City of Altoona, PA Stormwater Management, Erosion and Sedimentation Control

It shall be unlawful for any person, landowner, business or corporation to undertake any earthmoving activities without developing, implementing, and maintaining erosion and sedimentation control measures and facilities that effectively minimize accelerated erosion and prevent sediment pollution to waters of the commonwealth, both during and after construction. These controls shall be contained in an erosion and sedimentation control plan that meets the requirements of the Department of Environmental Protection (25 Pa. Code, Chapter 102, Erosion and Sediment Control Regulations). An approved copy of the erosion and sedimentation control plan must be available at the earthmoving site at all times. An additional approved copy must be provided by the applicant to the Director of the City of Altoona Inspections Department and to the Director of Public Works.

Prior to the commencement of any improvement which involves an earthmoving disturbance greater than 5,000 square feet, all erosion and sedimentation control plans must be submitted by the applicant to, and approved by, the Blair County Conservation District prior to formal approval of land development plans or the issuance of any building or other permit by the City of Altoona. In addition, all earthmoving disturbances for sites involving one acre or more and/or runoff to the storm sewer or one acre or more will require that the appropriate Department of Environmental Protection permit and review be obtained from the Department of Environmental Protection or the Blair County Conservation District.

All Pennsylvania Department of Environmental Protection and/or Blair County Conservation District permits reviews involving earthmoving disturbances shall be attached to said approved plan and shall be the responsibility of the applicant to obtain. Copies of the approved erosion and sedimentation control plans must be submitted to the City of Altoona Department of Inspections, and the City Engineering Department.

All earthmoving activities less than 5,000 square feet shall be exempt from plan and permit approvals; however, all other provisions of this article shall apply. Best management practices must be implemented to prevent sediment from leaving the site.

For all regulated earth disturbance activities, erosion and sediment control best management practices shall be designed, implemented, operated, and maintained during the regulated earth disturbance activities (e.g. during construction) to meet the purposes and requirements of this chapter and to meet all requirements under Title 25 of the Pennsylvania Code and the Clean Streams Law.[1] Various best management practices and their design standards are listed in the Erosion and Sediment Pollution Control Program Manual, aka the E&S Manual, No. 363-2134-008, dated April 15, 2000, as amended and updated.

[1]

Editor's Note: See 35 P.S. § 691.1 et seq.

All E&S and stormwater facilities shall be conducted and constructed to minimize accelerated erosion and resulting sediment pollution. Measures to control erosion and resulting sediment pollution shall, at a minimum, meet the standards of 25 Pa. Code, Chapter 102, Erosion and Sediment Pollution Control, and the latest edition of the Erosion and Sediment Pollution Control Manual.

§ 620-2 Plan contents.

Erosion and sedimentation control plans shall be developed in accordance with the Department of Environmental Protection Regulations, which include 25 Pa. Code Chapter 93 requirements for water quality standards and antidegradation. A complete explanation of the regulations and recommendations for preparing plans is available in the Department of Environmental Protection's publication, Erosion and Sediment Pollution Control Program Manual, aka the E&S Manual, as amended and updated. This manual is available from the local County Conservation District, 1407 Blair Street, Hollidaysburg, Pennsylvania, 16648; phone (814) 696-0877.

§ 620-3 Definitions.

See Article II, § 620-10.

§ 620-4 Administration.

Application for approval of an erosion and sedimentation control plan under the requirements of this article shall be made directly to the Blair County Conservation District. Information on submission and resubmission requirements, review time required, cost of permits, and plan review fees can be obtained from the Blair County Conservation District offices. For penalties and enforcement remedies, preventive remedies, jurisdiction and appeals to court, see §§ ections 620-17 and 620-18.

§ 620-5 Fees.

Municipal fees. Fees payable to the City are established by resolution of the City Council from time to time.

County fees. Fees for the review and comment on erosion and sedimentation control plans will be at the discretion of the Blair County Conservation District, and payable thereto.

Filing date and payment of fees. A completed application and plans for any proposed erosion and sediment pollution control plan shall not be considered as filed until all fees are paid, if applicable, and all applications are properly signed.

§ 620-6 Monitoring.

The City of Altoona and the Blair County Conservation District are hereby authorized to conduct both routine and emergency site inspections of ongoing earthmoving operations within the municipal boundaries to establish compliance with the approved erosion and sedimentation control plan.

§ 620-7 Compliance.

All violations of this article and/or the Department of Environmental Protection Chapter 102 Regulations, as determined during a site inspection, shall be listed on an inspection report which itemizes the following items for each violation:

Specific type of violation, including location and scope.

Provides a period of time during which the person(s) responsible for the earthmoving activity may correct the violations without the assessment of any penalties.

The inspection report shall be signed by the inspector and person responsible for the earthmoving activity (or authorized agent) and a copy provided to the latter party.

§ 620-8 Enforcement.

See Article II, § 620-17.

Article II Stormwater Management

§ 620-9 General Provisions.

Short title. This article shall be known and may be cited as "Altoona Stormwater Management Regulations."

Statement of findings. The City Council of the City of Altoona finds that:

(1)

Stormwater runoff from lands modified by human activities threatens public health and safety by causing increased runoff flows and velocities, which overtaxes the carrying capacity of existing streams and storm sewers causing flooding, loss of water quality, and greatly increases the cost of public facilities to convey and manage stormwater.

(2)

Inadequate planning and management of stormwater runoff, as well as inadequate maintenance of stormwater facilities and best management practices (BMPs), resulting from land development and redevelopment throughout a watershed can also harm surface water resources by changing the natural hydrologic patterns, accelerating stream flows (which increase scour and erosion of stream beds and stream banks thereby elevating sedimentation and aggregation), destroying aquatic habitat and elevating aquatic pollutant concentrations and loadings such as sediments, nutrients, heavy metals, and pathogens.

(3)

These impacts happen mainly through a decrease in natural infiltration of stormwater, with groundwater resources impacted through loss of recharge for water supplies and base flow of streams, which protects and maintains surface water quality.

(4)

A comprehensive program of stormwater management, including reasonable regulation of development and other activities causing loss of natural infiltration, is fundamental to the public health, safety, welfare, and the protection of the people of the City of Altoona, and all the people of the commonwealth including the greater Susquehanna River/Chesapeake Bay Watershed, their resources and the environment.

(5)

Stormwater is an important resource. Public education on the control of pollution from stormwater is an essential component in successfully addressing stormwater and stormwater management issues.

(6)

Federal and state regulations require the City to implement a program of stormwater controls. The City is required to obtain a federal permit for stormwater discharges from its storm sewer systems under the National Pollutant Discharge Elimination System (NPDES).

(7)

Permittees are required to enact, implement, and enforce a prohibition of nonstormwater connections and discharges to their separate storm sewer systems (MS4s) under their NPDES permit. Nonstormwater discharges to separate storm sewer systems can contribute to pollution of waters of the commonwealth by the City.

Purpose. The purpose of these regulations is to promote the public health, safety and welfare within the City and its watershed by minimizing the damages and maximizing the benefits described in § 620-9 of this article by provisions designed to:

(1)

Assure safe management of stormwater runoff resulting from land alteration and disturbance activities in accordance with watershed stormwater management plans adopted pursuant to the Pennsylvania Stormwater Management Act[1] (Act 167 of 1975, as amended).

[1]

Editor's Note: See 32 P.S. § 680.1 et seq.

(2)

Utilize and preserve existing natural drainage systems to the extent possible, and to preserve the flood carrying capacity of streams.

(3)

Encourage natural infiltration of rainfall to preserve groundwater recharge supplies and stream flows, and to prevent degradation of surface and groundwater quality and to otherwise protect water resources.

(4)

Provide for proper and adequate operation and maintenance of all permitted stormwater management facilities and stormwater management BMPS within the municipality.

(5)

Provide standards to achieve compliance with the requirements of the City's stormwater NPDES permit requirements.

(6)

Provide review procedures, performance standards, and design criteria for stormwater planning and management.

(7)

Meet legal water quality requirements under federal and state law, including the regulations of 25 Pa. Code Chapter 93 to protect, maintain, reclaim, and restore the existing and designated uses and maintain the level of water quality to support those uses in all waters of the commonwealth, and to protect and maintain water quality in special protection streams.

(8)

Prevent stream bank and streambed scour and erosion.

(9)

Manage stormwater impacts close to the runoff source, which requires a minimum of structures and relies on natural processes.

(10)

Implement an illegal discharge detection and elimination program to address nonstormwater discharges into the separate storm sewer system.

Statutory authority. The City also is empowered to regulate land use activities that affect runoff by the authority of the Act of July 31, 1968, P.L. 805, No. 247. The Pennsylvania Municipalities Planning Code, as amended, and/or the Act of October 4, 1978, P.L. 864 (Act 167), 32 P.S. § 680.1 et seq., as amended, the Stormwater Management Act.

Applicability. All regulated activities and all activities involving alteration, land development, or earth disturbance deemed to have possible effects upon stormwater runoff characteristics and/or any activity that may contribute nonstormwater discharges to a regulated MS4 are included within the scope and subject to regulation by this chapter. Examples include, but are not limited to:

(1)

Subdivision or parcels of subdivision.

(2)

Land development.

(3)

Construction of new or additional impervious surfaces with reduced permeability (driveways, parking lots, etc.).

(4)

Installation, additions, replacement or substantial repair of stormwater systems or appurtenances.

(5)

All earthmoving activities, including but not limited to those as regulated or required by the Erosion and Sediment Pollution Control Ordinance of the City of Altoona.

(6)

Placement of fill, structure(s), or pipe(s) in the floodplains, as designated on the official floodplain map and as may be documented by other pertinent sources of floodplain information used by the City.

(7)

Construction of new buildings or additions to existing buildings.

(8)

Forest management operations.

(9)

Nursery operations.

(10)

Diversion or piping of any natural or man-made stream channel.

(11)

Mining operations.

(12)

In general, this article applies to any land development activities within the City, all stormwater runoff entering into the separate storm sewer system from lands within the City, as well as existing and proposed stormwater best management practices.

(13)

Stormwater activities are also regulated under existing state or federal law and their implementing regulations. The article shall operate in conjunction with those parallel requirements; the requirement of this article shall be no less restrictive in meeting these purposes than state or federal law.

Compatibility with other requirements. Actions taken under this chapter do not affect any responsibility, permit or approval for any activity regulated by any other code, law, regulation, or ordinance.

Erroneous permit. Any permit or authorization issued or approved based on false, misleading or erroneous information provided by an applicant is void without the necessity of any proceedings for revocation. Any work undertaken or use established pursuant to such permit or other authorization is unlawful. No action may be willingly and with knowledge of purport to validate such a violation.

§ 620-10 Definitions.

Hierarchy of definitions. In determining the meaning of a word in this chapter, the hierarchy below shall apply. The reader should use the definition appearing in the highest priority document, unless the context of the language clearly indicates otherwise.

(1)

The definitions listed below shall have first priority.

(2)

The definitions shown for a specific referred chapter shall have second priority.

(3)

The definitions listed in the Pennsylvania Stormwater BMP Manual shall have third priority.

(4)

Definitions not listed in any document above shall be based on common American English vernacular and have last priority.

General rules. Unless otherwise expressly stated, the following words shall, for the purpose of this chapter, have the meanings herein indicated.

(1)

Words used in the present tense include words in the future tense.

(2)

The singular number includes the plural.

(3)

Masculine gender includes the feminine gender, and vice versa.

(4)

The word "include" and its various grammatical forms shall not limit the term to the specific listing or example given but is intended to extend its meaning to all other instances of like kind and character.

(5)

The words "shall," "will" and "must" are mandatory.

(6)

The words "may," "could" and "should" are permissive.

(7)

The words "used" and "occupied" include the concepts of "intended," "designed," "maintained" or "arranged" to be used or occupied.

Definitions.

ABACT ANTIDEGRADATION BEST AVAILABLE COMBINATION OF TECHNOLOGIES

Environmentally sound and cost effective treatment, land disposal, pollution prevention and stormwater reuse BMPs that individually or collectively manage the difference in the net change in stormwater volume, rate, and quality for storm events up to and including the two-year/twenty-four-hour storm when compared to the stormwater rate, volume and quality prior to the earth disturbance activities to maintain and protect the existing quality of the receiving surface waters of this commonwealth.

ABUTTING

Parcels shall be considered to be abutting when they touch or their lot lines are directly across from easements, utilities, parks, watercourses, water bodies, natural features, or private rights-of-way.

ACCELERATED EROSION

The removal of the surface of the land through the combined action of human activities and natural processes at a rate greater than would occur because of the natural processes alone.

ACRE

A acre contains 43,560 square feet.

ADJOINING

See "abutting."

ADVERSE IMPACT

A condition that creates, imposes, aggravates, or leads to inadequate, impractical, unsafe, or unhealthy conditions on a site proposed for development or on off-tract property or facilities.

ADVERSE POSSESSION

The right of an occupant to acquire title to a property after having continuously and openly used and maintained such property over a period of 21 years without protest from the owner(s) of record.

AESTHETIC

The perception of artistic elements or elements in the natural or created environment that are pleasing to the eye.

AGRICULTURAL ACTIVITY

Activities associated with agriculture such as agricultural cultivation, agricultural operation, and animal heavy use areas. This includes the work of producing crops including tillage, land clearing, plowing, disking, harrowing, planting, harvesting crops or pasturing and raising livestock and installation of conservation measures. Construction of new buildings or impervious area is not considered an agricultural activity.

AGRICULTURAL OPERATIONS

The production, keeping, or maintenance for sale, lease, or personal use of plants and animals useful to man. These activities shall include, but are not limited to, forages and sod crops; grains and seed crops; dairy animals and dairy products; poultry animals and poultry products; livestock, including beef cattle, sheep, swine, horses, ponies, mules, goats, or any mutations or hybrids thereof, including the breeding and grazing of any and all such animals; bees and apiary products; fur animals; trees and forest products; fruits of all kinds, including nuts and berries; vegetables; nursery, floral, ornamental and greenhouse products; or lands devoted to a soil conservation or forestry management program; and establishments primarily engaged in supplying soil preparation services, crop services, horticultural services, veterinary and other animal services, and farm labor and management services. It does not include landscaping services.

AISLE

The traveled way by which cars enter and depart parking spaces.

ALKALINITY

A measure of the capacity of water to neutralize acids because of the presence of one or more of the following bases in the water: carbonates, bicarbonates, hydroxides, borates, silicates, or phosphates,

ALLEY

A minor public or private thoroughfare other than a side street, which affords only a secondary means of access to abutting property and not for general traffic circulation.

APPEAL

A means for obtaining review of a decision, determination, order, or failure to act pursuant to the terms of this chapter.

APPLICANT

An individual, including his or her heirs, successors and assigns, making application according to the regulations contained in this chapter, and whose signature appears on any application. The "applicant" must be the property owner or authorized agent.

APPLICATION

(1)

(verb) The submitting of an application for permit or service in a complete state.

(2)

(noun) The document which an applicant completes, along with all supporting documents, exhibits, and plans required for development review purposes or for approval to engage in any regulated activity at a project site.

APPOINTING AUTHORITY

Altoona City Council or its designee.

APPROVING AUTHORITY/BODY

The agency, board, group, or other legally designated individual or agency that has been charged with the review and approval of applications.

ASPECT RATIO

Ratio of wetland cell length to width.

ATTENUATION

Reduction in magnitude, as in the lowering of peak runoff discharge rates, in the case of dry ponds; or the reduction of contaminant concentrations, as in the action of biodegradation in wetlands or bioretention facilities.

AUTHORITY

A political or corporate body created pursuant to the former act of May 2, 1945 (P.L. 382, No. 164), known as the "Municipality Authorities Act of 1945."[1]

AUTHORIZED CITY REPRESENTATIVE

Staff member assigned to represent the City of Altoona.

BASE FLOW

Normally refers to the stream levels associated primarily with groundwater or subsurface contributions, as opposed to storm flow which corresponds to stream levels associated with recent precipitation and surface runoff.

BEDROCK

Layer of consolidated rock over which lies an overburden of soil (regolith), including unconsolidated rock.

BENTHIC

Pertaining to occurrence on or in the bottom sediment of wetland and aquatic ecosystems, including wetlands.

BERM

A mound of earth, or the act of creating such a mound.

BEST MANAGEMENT PRACTICE (BMP)

(1)

Activities, facilities, designs, measures, or procedures used to manage stormwater impacts from regulated activities, to meet state water quality requirements, to promote groundwater recharge, and to otherwise meet the purposes of this chapter. Stormwater BMPs are commonly grouped into one or two broad categories or measures: structural or nonstructural. In this chapter, nonstructural BMPs or measures refer to operational and/or behavior-related practices that attempt to minimize the contact of pollutants with stormwater runoff whereas structural BMPs or measures are those that consist of a physical device or practice that is installed to capture and/or treat stormwater runoff. Structural BMPs include, but are not limited to, a wide variety of practices and devices, from large-scale retention ponds and constructed wetlands, to small-scale underground treatment systems, infiltration facilities, filter strips, low impact design, bioretention, wet ponds, permeable paving, grassed swales, riparian or forested buffers, sand filters, detention basins, and manufactured devices. Structural stormwater BMPs are permanent appurtenances to the project site.

(2)

Management activities, facilities, measures, or procedures used to minimize pollution to the waters of the commonwealth.

(3)

Activities, facilities, measures, or procedures used to manage the volume, rate and water quality of stormwater runoff.

BIOCHEMICAL OXYGEN DEMAND (BOD)

A measure of the concentration of aerobically degradable compounds in water. It is measured as the oxygen consumed during degradation of organic and inorganic materials in water.

BIODIVERSITY

The number of species of plants and animals in a defined area. Biodiversity is measured by a variety of indices that consider the number of species and, in some cases, the distribution of individuals among species.

BIOMASS

The total mass of living tissues (plant and animal).

BIORETENTION

A method of treating stormwater by pooling water on the surface and allowing filtering and settling of suspended solids and sediment at the mulch layer, prior to entering the plant/soil/microbe complex media for infiltration and pollutant removal.

BIOSWALE

A swale which promotes infiltration and pollutant reduction by use of amended soils allowing filtering and settling of suspended solids and sediment through the mulch and amended soil layer.

BMP FINGERPRINING

A series of techniques for locating BMPs (particularly ponds) within a development site so as to minimize their impacts to wetlands, forest, and sensitive stream reaches.

BMP MANUAL

Pennsylvania Department of Environmental Protection Stormwater Best Management Practices Manual, as amended or revised.

BOARD

Any body granted jurisdiction under a land use ordinance or under this chapter to render final adjudications. In this chapter, this term usually, but not always, refers to the Zoning Hearing Board.

BUFFER

A vegetated strip immediately adjacent to a water body. The primary function of buffers is to protect the receiving water from sediment and pollutants derived from upstream areas. Ancillary benefits may include infiltration of rainfall and habitat enhancement. A buffer is a special case of a filter strip. Forested riparian buffers are one example of a best management practice related to the use of buffers.

BUFFER AREA

An open area made available to physically separate two land uses. A buffer area exists laterally; it does not in and of itself include screening, fences, landscaping, or other treatments which exist on a vertical plane to provide additional separation between uses.

BUILDING FOOTPRINT

The area of ground hidden by a building when the building is viewed from directly above.

CALIPER

The diameter of a tree trunk.

CAMPUS

The grounds and buildings of an institution, educational facility, or business park.

CARPORT

A structure with at least three sides open used for storage of one or more vehicles.

CARTWAY

The portion of a street right-of-way, paved or unpaved, intended for vehicular traffic.

CATCH BASIN

A storm sewer inlet; see inlet.

CENTER LINE

The projected line running exactly halfway between and parallel to the right-of-way lines of a street.

CERTIFICATE OF FLOODPLAIN COMPLIANCE

A certificate issued by the Floodplain Permit Officer after it has been determined that all construction, development, use of land, or interior repair have been completed according to the requirements of this chapter. No structure shall be occupied, use undertaken, or dedication accepted by the City until after a certificate of floodplain compliance has been legally issued.

CHANNEL

A perceptible natural or artificial waterway which periodically or continuously contains moving water or which forms a connecting link between two bodies of water. It has a definite bed and banks which confine the water.

CHANNELIZATION

The creation of a channel or channels resulting in faster water flow, a reduction in hydraulic residence time, and less contact between water and solid surfaces in the water body.

CHOKER COURSE

A filter layer of finer material, usually crushed stone, that is installed over a coarse road base material. The purpose of the choker course is to provide a stable foundation for the construction of a pavement.

CISTERN

An underground reservoir or tank for storing rainwater.

CITY

Altoona, Pennsylvania.

CITY COUNCIL

The governing body of the City of Altoona.

COMMISSION

The Altoona City Planning Commission.

COMMON OPEN SPACE

A parcel or parcels of land, an area of land, an area of water, or a combination of land and water within a development site designed and intended for the use or enjoyment of residents of the development, not including streets, off-street parking areas, and areas set aside for public facilities.

COMMON OWNERSHIP

Ownership by one or more individuals in any form of ownership of two or more contiguous lots.

COMPLETE STATE

An application submitted with all required, relevant and pertinent information necessary for the approving body to render an informed decision.

COMPLETELY DRY SPACE

A space which will remain totally dry during flooding; the structure is designed and constructed to prevent the passage of water and water vapor.

COMPREHENSIVE PLAN

When capitalized, the Comprehensive Plan for Altoona, as it may be amended from time to time. Otherwise, a plan plus any amendments or any of its component parts for the development of a county or municipality, providing the continuing orderly development of the municipality. The plan includes such elements as a statement of community development objectives, plans and policies for land use, housing, transportation, community facilities and utilities, and strategies for plan implementation.

CONCENTRATED WATER FLOW AREAS

Those natural or manmade ares where stormwater runoff is channeled and conveyed directly to a surface body of water. Concentrated water flow areas include but are not limited to ditches, waterways, gullies, and swales.

CONSERVATION DISTRICT

(The Blair County Conservation District). A conservation district, as defined in Section 3(c) of the Conservation District Law [3 P.S. § 851(c)] that has the authority under a delegation agreement executed with DEP to administer and enforce all or a portion of the regulations promulgated under 25 Pa. Code 102.

CONSERVATION PLAN

A plan that identifies conservation practices and includes site specific BMPs for agricultural plowing or tilling activities and animal heavy use areas.

CONSTRUCTION

Any grading, excavating, or placing of earth fill, erection of buildings or other structures, including the grubbing and clearing of trees, brush, and other vegetation; provided, however, that any such activity in connection with farming, forestry, test boring or surveying shall not be deemed construction. Also includes the reconstruction, renovation, repair, extension, expansion, alteration, adaptive reuse, rehabilitation, restoration or relocation of a building or structure, including the placement of a manufactured home.

CONSTRUCTION PLAN

The maps, plans, plats, or drawings accompanying a development plan and showing the specific location and design of improvements to be installed in the project in accordance with the requirements of this chapter.

COUNTY

Blair County, Pennsylvania.

COUNTY PLANNING COMMISSION

The Blair County Planning Commission.

COVERAGE

See "building, coverage" and "lot, coverage."

CRITICAL DEPTH

The depth of flow at which the specific energy is a minimum for a given discharge rate. Flow is critical when the Froude number is equal to one:

where V, is the velocity of the flow, g, is the gravitational constant, and D, is the hydraulic depth of the flow.

CULVERT

A pipe, conduit, or similar structure for the free passage of surface drainage through or under a highway, railroad, canal, or other embankment.

CUT

(1)

An excavation.

(2)

The difference between a point on the original ground and designated point of lower elevation on the final grade.

(3)

Also, the material removed in excavation.

DECISION

Final adjudication of any board or other body granted jurisdiction under any land use ordinance or this chapter to do so, either by reason of the grant of exclusive jurisdiction or by reason of appeals from determinations.

DEDICATION

The deliberate appropriation of land by its owner for any general and public use, reserving to himself no other rights than those that are compatible with the full exercise and enjoyment of the public uses to which the property has been devoted.

DENSE GRADED MATERIAL

Granular mixture characterized by a large range in particle sizes. Dense graded materials have superior structural properties to open graded materials. However, they are less permeable.

DENSITY

The cumulative measure of the average number of items in a specific space.

DEP

The Pennsylvania Department of Environmental Protection.

DEPARTMENT

Altoona City departments may be referred to in this manner when the context is appropriate,

DEPARTMENT OF ENVIRONMENTAL PROTECTION

The Pennsylvania Department of Environmental Protection, its bureaus, departments, or divisions. May be abbreviated as PA DEP or DEP.

DEPARTMENT OF TRANSPORTATION

The Pennsylvania Department of Transportation, its bureaus, departments, districts, or divisions. May be abbreviated as PennDOT.

DESIGN CONTINUITY

A unifying or connecting theme or physical feature for a particular setting or place.

DESIGN CRITERIA

(1)

Engineering guidelines specifying construction details and materials.

(2)

Objectives, results, or limits which must be met by a facility, structure, or process in performance of its intended functions.

DESIGN FIT

Continuity in a scale, quality, or character between new and existing development so as to avoid abrupt or severe differences.

DESIGN STORM

The magnitude and temporal distribution of precipitation from a storm event measured in probability of occurrence (e.g., fifty-year storm) and duration (e.g., 24 hours), and used in the design and evaluation of stormwater management control systems. Also see "return period."

DESIGN VOLUME

The volume of runoff that is captured and released into the waters of the commonwealth at a controlled rate.

DETENTION

The slowing, dampening or attenuating of runoff flows entering the natural drainage pattern or storm drainage system by temporarily holding water on a surface area in a detention basin or within the drainage system.

DETENTION BASIN

A basin designed to retard stormwater runoff by temporarily storing the runoff and releasing it at a predetermined rate. A detention basin is designed to drain completely after a storm event.

DETENTION FACILITIES

Can be above or below ground, open or enclosed, including but not limited to pipe storage, wet ponds, basins, rain gardens, bioretention areas, etc. For further reference, refer to the City of Altoona Planning Code and the DEP BMP Manual for further examples.

DETENTION VOLUME

The volume of runoff that is captured and released into the waters of the commonwealth at a controlled rate.

DETERMINATION

Final action by an officer, body, or agency charged with the administration of any land use ordinance or applications thereunder, except City Council, the Zoning Hearing Board, and the Planning Commission.

DEVELOPER

The person, persons, or any corporation, partnership, association, or other entity or any responsible person therein or agent therefor that undertakes the activities associated with changes in the built or human environment. The term "developer" is intended to include but not necessarily be limited to the terms "subdivider," "owner," and "builder" even though the individuals involved in successive stages of a project may vary.

DEVELOPMENT

Any man-made change to improved or unimproved real estate, including, but not limited to, the construction, reconstruction, renovation, repair, expansion, or alteration of buildings or other structures; the placement of streets and other paving; any activity affecting stormwater runoff characteristics; utilities; filling, grading and excavation; mining; dredging; drilling operations; storage of equipment or materials; and the subdivision of land.

DEVELOPMENT PLAN

The provision for development including a plat, all covenants relating to use, location and bulk of buildings and other structures, intensity of use or density of development, streets, ways and parking facilities, common open space and public facilities. The phrase "provisions of the development plan," when used in this chapter, shall mean the written and graphic materials referred to in this definition.

DEVELOPMENT SITE

See project site.

DEVELOPMENT WHICH MAY ENDANGER HUMAN LIFE

In accordance with the Pennsylvania Floodplain Management Act[2] and regulations adopted by the Department of Community and Economic Development pursuant to that act, any activity requiring the production, storage, use of any amount of radioactive substances; structures or land used for the production or storage of any quantity of the following materials; or structures or land used for any activity requiring the maintenance of a supply (more than 550 gallons or other comparable volume) of the following materials;

Acetone.

Ammonia.

Benzene.

Calcium carbide.

Carbon disulfide.

Celluloid.

Chlorine.

Hydrochloric acid.

Hydro cyanic acid.

Magnesium.

Nitric acid and oxides of nitrogen.

(12)

Petroleum products (gasoline, fuel oil, etc.).

Phosphorus.

Potassium.

Sodium.

Sulfur and sulfur products.

(17)

Pesticides (including insecticide, fungicides and rodenticides).

(18)

Radioactive substances, insofar as such substances are not otherwise regulated.

DISCHARGE

The flow or rate of flow from a canal, conduit, channel or other hydraulic structure.

DISTURBED AREA

An unstabilized land area where an earth disturbance activity is occurring or has occurred.

DITCH

A trench dug in the ground that is shaped in a V or U that conveys stormwater.

DIVERSION TERRACE

A channel and a ridge constructed to a predetermined grade across a slope and designed to collect and divert runoff from slopes which are subject to erosion.

DRAINAGE

The removal of surface water or groundwater from land by drains, grading or other means, and includes control of runoff to minimize erosion and sedimentation during and after construction or development.

DRAINAGE AREA

(1)

The area of a drainage basin or watershed, expressed in acres, square miles, or other unit of area. Also called "catchment area," "watershed," "river basin."

(2)

The area served by a sewer system receiving stormwater and surface water or by a watercourse.

DRAINAGE EASEMENT

A right granted by a landowner to a grantee allowing the use of private land for stormwater management purposes.

DRAINAGE FACILITY

Any ditch, gutter, culvert, storm sewer or other structure designed, intended, or constructed for the purpose of carrying, diverting, or controlling surface water or groundwater.

DRIVEWAY

A private vehicular passageway providing access between a street and a private parking area or private garage.

DRY SWALE

The dry swale consists of an open channel capable of temporarily storing the water quality treatment volume, and a filtering medium consisting of a soil bed with an underdrain system. The dry swale uses volume-based sizing criteria. The dry swale is designed to drain down between storm events within approximately one day. The water quality treatment mechanisms are similar to bioretention practices, except that the pollutant uptake is likely to be more limited since only a grass cover crop is available for nutrient uptake.

E&S

Erosion and sedimentation.

E&S PERMIT

A permit required for earth disturbance activities where the earth disturbance is associated with timber harvesting, road maintenance activities, or oil and gas activities.

EARTH DISTURBANCE ACTIVITY

A construction or other human activity which disturbs the surface of the land, including, but not limited to: land clearing and grubbing, grading, excavations, embankments, land development, agricultural plowing or tilling, operation of animal heavy use areas, timber harvesting activities, road maintenance activities, oil and gas activities, well drilling, mineral extraction, and the moving, depositing, stockpiling, or storing of soil, rock or earth materials. Earth disturbance activity is subject to regulation under 25 Pa. Code 92, 25 Pa. Code 102, and/or the Clean Streams Law.[3]

EASEMENT

The grant of one or more property rights by the property owner to and/or for use by the public, a corporation, an entity, or a person or persons.

ECOSYSTEM

All organisms and the nonliving environmental factors with which they interact.

ELEVATION

An elevation measured from a datum plane. For the purpose of this chapter, all elevations are referenced to the National Geodetic Vertical Datum of 1929 (NGVD) based on mean sea level.

ELEVATION PLAN OR VIEW

A plan view of a building drawn as it would appear if the viewer were looking at the building across a horizontal plane standing at ground level.

EMERGENT PLANT

A rooted, vascular plant that grows in periodically or permanently flooded areas and has parts of the plant (stems and leaves) extending through and above the water plane.

EMINENT DOMAIN

The authority to acquire or take, or to authorize the taking of, private property for public use or public purpose.

ENCROACHMENT

Any structure or activity which in any manner changes, expands or diminishes the course, current or cross section of any watercourse, floodway or body of water, or intrudes within established regulatory or ownership boundaries.

ENGINEER

An individual licensed and registered under the laws of the commonwealth of Pennsylvania to engage in the practice of engineering. An engineer shall not practice land surveying as defined and set forth in this chapter, unless the engineer is also a registered surveyor.

ENGINEERING

The application of the mathematical and physical sciences for the specific design of any construction, development, use of land, or interior repair as defined herein.

ENGINEERING SPECIFICATIONS

The engineering criteria of the City of Altoona regulating the installation of any improvement or facility.

EROSION

The natural process by which the surface of the land is worn away by water, wind, ice, glaciers, or chemical action.

EROSION AND SEDIMENTATION (E&S) CONTROL

The application of measures to reduce erosion and sedimentation to land surfaces.

EROSION AND SEDIMENTATION (E&S) CONTROL PLAN

A plan for a project site which identifies best management practices to minimize accelerated erosion and sedimentation resulting from the removal of the surface of the land through the combined action of man's activities and natural processes.

ESSENTIALLY DRY SPACE

A space which will remain dry during flooding, except for the passage of some water vapor or minor seepage; the structure is substantially impermeable to the passage of water.

EUTROPHIC

Water containing an excess of plant-growth nutrients that typically result in algae blooms and extreme (high and low) dissolved-oxygen concentrations.

EVAPOTRANSPIRATION

The combined processes of evaporation from the water or soil surface and transpiration of water by plants.

EXCAVATION

Any act by which earth, sand, gravel, rock, or any other material is dug into, cut, quarried, uncovered, removed, displaced, relocated, or bulldozed. It shall include the conditions resulting therefrom.

EXCESSIVELY RAPID DRAINAGE

For purposes of the PA BMP manual, this corresponds to infilitration rates of soils in excess of six inches per hour. (Normally six inches is considered rapid drainage but the PA BMP manual indicates that special precautions need to be taken with an infiltration rate of six inches per hour or more.)

EXFILTRATE

The leaking of water to surrounding ground through openings in structures.

EXISTING CONDITION

The dominant land cover during the five-year period immediately preceding a proposed regulated activity.

EXOTIC SPECIES

A plant or animal species that has been intentionally or accidentally introduced and that does not naturally occur in a region.

EXTENDED DETENTION

A function provided by BMPs which incorporate a water quality storage. BMPs with extended detention, intercept runoff and then release it over an extended period of time.

EXTENDED DETENTION (ED) POND

Temporarily detains part of stormwater runoff for up to 24 hours after a storm by using a fixed orifice. ED ponds normally are "dry" between storm events and do not have permanent standing water. An enhanced ED pond is designed to prevent clogging and resuspension. It provides flexibility in achieving target detention times. It may be equipped with plunge pools near the inlet, a micropool at the outlet, and may have an adjustable reverse-sloped pipe at the ED control device.

EXTENDED DETENTION CONTROL DEVICE

A pipe or series of pipes that extend from the riser of the stormwater pond that are used to gradually release stormwater from the pond over a twelve- to forty-eight-hour interval.

FASCINE

Bundled willow cuttings used to stabilize stream banks. Bundling allows otherwise weak green twigs to reinforce each other and resist the forces of stream currents.

FEMA

The Federal Emergency Management Agency.

FIELD CAPACITY

The quantity of water which will not freely drain from the root zone of shallow soil layers. Usually measured as the moisture content (by volume) in soil at a capillary tension of .33 bars.

FILL

Sand, gravel, earth or other material placed or deposited so as to form an embankment or raise the elevation of the land surface. The term includes material used to replace an area with aquatic life with dry land or to change the bottom elevation of a surface water area.

FILTER STRIP

A vegetated boundary characterized by uniform mild slopes. Filter strips may be provided down-gradient of developed tracts to trap sediment and sediment-borne pollutants and to reduce imperviousness. Filter strips may be forested or vegetated turf. Filter strips located adjacent to waterbodies are called buffers.

FLASH BOARDS

Removable boards used in a weir to control water levels.

FLOATING AQUATIC PLANT

A rooted or non-rooted vascular plant that is adapted to have some plant organs (generally the chlorophyll-bearing leaves) floating on the surface of the water in wetlands, lakes, and rivers.

FLOOD

A temporary inundation of normally dry land areas.

FLOOD FRINGE

The flood fringe occupies the distal parts of the floodplain, outside of the floodway. Complete obstruction of the flood fringe will not significantly increase flood levels. The flood fringe boundary is typically based on an increase in flood level of one foot during the one-hundred-year return frequency flooding event.

FLOOD INSURANCE RATE MAP (FIRM)

The official map on which the Federal Emergency Management Agency or Federal Insurance Administration has delineated both the areas of special flood hazards and the risk premium zones applicable to the community.

FLOOD INSURANCE STUDY (FIS)

The official report provided by the Federal Insurance Administration that includes flood profiles, the Flood Insurance Rate Map, the Flood Boundary Map, and the water surface elevation of the base flood.

FLOODPLAIN

(1)

Any land susceptible to being inundated by water from any source during the base flood, as delineated on the most current floodplain maps prepared by the Federal Insurance Administration and approved by the Federal Emergency Management Agency (FEMA) for the purpose of determining the official federal designated floodplain, floodway and floodway fringe. These maps are based on the most current Flood Insurance Study prepared by the Federal Emergency Management Agency; the study being the definitive source of floodplain information, particularly in regards to base flood elevations and floodway widths as reflected in the floodplain regulations of the City of Altoona and indicated on the flood boundary and Floodway Maps. Also includes areas that comprise Group 13 soils, as listed in Appendix A of the DEP Technical Manual for Sewage Enforcement Officers, as amended.

(2)

Lands adjoining a river or stream that have been or may be expected to be inundated by flood waters in a one-hundred-year frequency flood.

FLOODPLAIN ADMINISTRATOR

The individual appointed to enforce the provisions of floodplain ordinance.[4]

FLOODWAY

The channel of a water course and those portions of the adjoining floodplains that are reasonably required to carry and discharge the one-hundred-year flood or base flood without cumulatively increasing the water surface elevation more than one foot. Unless otherwise specified, the boundary of the floodway is indicated on maps and flood insurance studies provided by FEMA. In any case where no FEMA maps or studies have defined the boundary of the one-hundred-year floodway, it is assumed (absent evidence to the contrary) that the floodway extends from the stream to 50 feet from the top of the bank of the stream.

FOREBAY

Stormwater design feature that uses a small basin to settle out incoming sediment before it is delivered to a stormwater BMP.

FOREST MANAGEMENT/TIMBER OPERATIONS

All activities connected with management of forestland. These include inventory, preparation, growing and harvesting of forest products including the site preparation, cultivation and logging of trees, and the construction and maintenance of roads.

FORESTRY ACTIVITIES

The management of forests and timberlands when practiced in accordance with accepted silvicultural principles, through developing, cultivating, harvesting, transporting and selling trees for commercial purposes, which does not involve any land developments.

FREEBOARD

The vertical distance between water surface elevation experienced during the design flood and the crest elevation of a dam, levee, floodwall or other embankment.

FRESH WATER

Water with a total dissolved solids content less than 500 mg/L (0.5 parts per thousand salts).

FRONTAGE

The linear distance which a property line runs coincident with a street right-of-way line. Frontage may be measured from any abutting street, but all required frontage must be measured from the same street. The street from which frontage is gained need not be the street to which the structure(s) on the lot are faced. Frontage cannot be gained from alleys, driveways, or elevated or buried roadways.

FRONTAGE ROAD

Minor collector streets parallel and adjacent to arterial streets, providing access to abutting properties and control of intersections with an arterial street.

GABION

Wire cage used to contain rip rap and stone. Gabions are used to increase the resistance of rip rap to movement caused by flowing water.

GENERAL PUBLIC

Any and all individuals, without any prior qualifications.

GEOTEXTILE

A fabric manufactured from synthetic fiber that is designed to achieve specific engineering objectives, including seepage control, media separation (e.g., between sand and soil), filtration, or the protection of other construction elements such as geomembranes.

GOVERNING BODY

The Altoona City Council.

GOVERNMENT FACILITIES

A building or lot owned or occupied by a governmental agency for any purpose.

GOVERNMENTAL AGENCY

Any department, commission, independent agency, or instrumentality of the United States, the commonwealth of Pennsylvania, a Pennsylvania county, the City of Altoona, a Pennsylvania municipality or authority. The administrative offices of a public school district are included, but no other school district use or building qualifies.

GRADE

The slope of ground, street, or other public way, specified in percentage of change in elevation per horizontal distance; the act of altering the topography of undisturbed land.

GRADE, FINISHED

The completed surfaces of lawns, walks, and roads brought to grades as shown on official plans or designs relating thereto.

GRASSED WATERWAY

A natural or man-made low-lying stretch of land which gathers or carries surface water runoff, also known as a "swale."

GREEN INFRASTRUCTURE

Systems and practices that use or mimic natural processes to infiltrate, evapotranspire, or reuse stormwater on the site where it is generated.

GREENWAY

A strip or belt of vegetated land that typically includes both upland and riparian areas. Greenways are often used for recreation, as a land use buffer, or to provide a corridor and habitat for wildlife.

GROUND COVER

Materials covering the ground surface.

GROUNDWATER

Subsurface water occupying the saturation zone from which wells and springs are fed.

GROUNDWATER RECHARGE

Replenishment of existing natural underground water supplies or groundwater naturally by precipitation or runoff.

HABITAT

The environment occupied by individuals of a particular species, population, or community.

HEADWALL

A wall of stone, metal, concrete, or wood at the end of a culvert or drain to protect fill from scour or undermining, increase hydraulic efficiency of conduit, divert flow, retard disjointing of short sectional pipe, or serve as a retaining wall.

HEARING

An administrative proceeding conducted by a board.

HEAVY METALS

Metallic elements having atomic weights above 21 on the periodic table.

HERBACEOUS

Plant parts that contain chlorophyll and are nonwoody.

HOLDING POND

A retention or detention pond.

HYDRAULIC CONDUCTIVITY (K)

An expression of the readiness with which a liquid such as water flows through a soil in response to a given potential gradient. Hydraulic conductivity is a constant physical property of soil or rock, one of several components responsible for the dynamic phenomenon of flow.

HYDRAULIC LOADING RATE (HLR)

Ratio of the surface area of a hydraulic device and the average rate at which water is delivered to the area. Measure of the application of a volume of water to a land area with units of volume per area per time or simply reduced to applied device water depth per time (for example, m³/(m²/d) or cm/d).

HYDRAULIC RESIDENCE TIME (HRT)

A measure of the average time that water occupies a given volume with units of time. The theoretical HRT is calculated as the volume divided by the flow (for example, m³/(m²/d)). The actual HRT is estimated on the basis of tracer studies that used conservative tracers such as lithium or dyes.

HYDRIC SOIL

A soil that is saturated, flooded, or ponded long enough during the growing season to develop anaerobic conditions. Hydric soil that is in areas having indicators of hydrophytic vegetation and wetland hydrology is wetland soil.

HYDROGRAPH

A record of the change in flow rate with time.

HYDROLOGIC SOIL GROUP (HSG)

(1)

Infiltration rates of soils vary widely and are affected by subsurface permeability as well as surface intake rates. Soils are classified into four HSGs (A, B, C, and D) according to their minimum infiltration rate, which is obtained for bare soil after prolonged wetting. The NRCS defines the four groups and provides a list of most of the soils in the United States and their group classification. The soils in the area of the development site may be identified from a soil survey report that can be obtained from local NRCS offices or conservation district offices. Soils become less pervious as the HSG varies from A to D.

(2)

A designation developed by the NRCS which describes the infiltration capacity of soil. Soil associations are categorized in decreasing infiltration capacity from A to D.

HYDROPERIOD

The period of wetland soil saturation or flooding. Hydroperiod is often expressed as a number of days or a percentage of time flooded during an annual period (for example, 25 days or 7%).

IMPACT FEE

A fee imposed on a development to finance the cost of improvements to services and infrastructure necessary to accommodate the development and its effects.

IMPERVIOUS

Not allowing or allowing only with great difficulty the movement of water; impermeable.

IMPERVIOUS SURFACE (IMPERVIOUS AREA)

A surface that prevents the infiltration or percolation of water into the ground. Impervious surfaces (or areas) shall include, but not be limited to: roofs, additional indoor living spaces, patios, garages, storage sheds and similar structures; and any new street, sidewalk, deck, parking lots, as well as driveway areas.

IMPLEMENTED (also IMPLEMENTATION)

Adequately applied or having a written schedule for implementation.

IMPROVEMENTS

Any physical addition or installation or construction required by the City to render land suitable for the use intended and including, but not limited to, streets, curbs and gutters, sidewalks, street signs and lights, walkways, sewer and water facilities, monuments and markers, grading, and stormwater drainage facilities.

INFILTRATION

(1)

The flow or movement of water through the interstices or pores of a soil or other porous medium.

(2)

The entrance or absorption of surface water into the soil, usually at the soil/air interface.

INFILTRATION STRUCTURES

A structure designed to direct runoff into the ground (e.g., french drains, seepage pits, seepage trenches).

INFILTRATION TESTING

Specific tests designed to measure the saturated movement of water into the soil in a single direction downward through a two dimensional soil surface.

INLET

There are four major types of stormwater inlets:

(1)

GRATED INLETStandard inlet of various sizes and various type grates.

(2)

CURB INLETHas an opening in the curb. Also referred to as an open mouth inlet.

(3)

GRATED/CURBED INLETInlet comprised of both a curb opening and a grate.

(4)

COMBINATION INLETInlet tied into the combined storm/sanitary sewer system.

INLET TRAP

An inlet trap is used on a combined sewer/storm sewer system. A ninety-degree bend turned down on the outlet pipe in an inlet. Water builds up in the inlet sump covering the bottom of the elbow thus preventing sewer gas from entering the inlet.

INTERMITTENT STREAM

A body of water flowing in a channel or bed composed primarily of substrates associated with flowing water, which, during periods of the year, is below the local water table and obtains its flow from both surface runoff and groundwater discharges.

KARST

A type of topography or landscape characterized by surface depressions, sinkholes, rock pinnacles/uneven bedrock surface, underground drainage, and caves. Karst is formed on carbonite rocks, such as limestone or dolomite.

KNOWINGLY

As used in this chapter, means having knowledge of, or reason to know, or a belief or ground for belief which warrants further inspection or inquiry of: the character and content of any material or performance described herein which is reasonably susceptible of examination by a licensee or person; the age of the minor; provided, however, that an honest mistake shall constitute an excuse from liability hereunder if the licensee or person made a reasonable bona fide attempt to ascertain the true age of such minor. "Knowingly" also means that a reasonable person using reasonable skills and faculties would have known or been aware.

LAND

Ground, soil, or earth, including structures on, above, or below the surface.

LAND DEVELOPMENT (DEVELOPMENT)

Inclusive of any or all of the following meanings: The improvement of one lot or two or more contiguous lots, tracts, or parcels of land for any purpose involving any activity enumerated in § 640-44 or as otherwise defined in the Municipalities Planning Code (Section 503(1.1).

LAND DISTURBANCE

Any activity involving the changing, grading, transportation, fill and any other activity which causes land to be exposed to the danger of erosion.

LAND SURVEYING

The location, relocation, establishment, reestablishment or retracement of any property line or boundary of any parcel of land or any lot right-of-way, easement, or alignment. This process shall include the principles of land surveying; determination of the position of any monument or reference point that marks a property line, boundary, or corner; setting, resetting, or replacing any such monument or individual point, including the writing of deed descriptions. This process shall also include the determination of elevations and topographic surveys. Land surveying shall be practiced by a surveyor or engineer registered under the laws of the commonwealth of Pennsylvania to engage in the practice of land surveying.

LANDLOCKED

Any lot or parcel without any access to the public roadway system.

LANDOWNER

The legal or beneficial owner or owners of land, including the holder of an option or contract to purchase (whether or not such option or contract is subject to any condition), a lessee if he or she is authorized under the lease to exercise the rights of the landowner, or other person having a proprietary interest in land.

LANDSCAPE

(1)

An expanse of natural scenery.

(2)

Lawns, trees, plants, rocks, wood chips, and decorative features such as sculptures, patterned walks, fountains, and pools.

LICENSED PROFESSIONAL

Professional engineers, landscape architects, geologists and land surveyors licensed to practice in this commonwealth.

LIMNETIC

Relating to or inhabiting the open water part of a freshwater body with a depth that light penetrates. The area of a wetland without emergent vegetation.

LITTORAL ZONE

The shoreward zone of a lake or wetland. The area where water is shallow enough for emergent vegetation to dominate.

LONG TERM OPERATION AND MAINTENANCE

The routine inspection, maintenance, repair or replacement of a BMP to ensure proper function for the duration of time that the BMP is needed.

LOW IMPACT DEVELOPMENT

Sight design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration, evapotranspiration, and the reuse of rainwater. LID can be applied to new development, urban retrofits, and revitalization projects LID utilizes design techniques that infiltrate, filter, evaporate, and store runoff close to its source. Rather than rely on costly large scale conveyance and treatment systems, LID addresses stormwater through a variety of small cost-effective landscape features located on-site.

MAINTENANCE

The upkeep necessary for efficient operation of physical properties or BMPs.

MANNING'S EQUATION

A formula for calculating the anticipated uniform flow in an open-channel flow, published by Manning in 1890.

MARSH

A wetland dominated by herbaceous emergent plants.

MEDIATION

A voluntary negotiating process in which parties in a dispute mutually select a neutral mediator to assist them in jointly exploring and settling their differences, culminating in a written agreement which the parties themselves create and consider acceptable.

MITIGATION

(1)

Methods used to alleviate or lessen the impact of development.

(2)

The replacement of functional values lost when an ecosystem is altered. Mitigation can include replacement, restoration, and enhancement of functional values.

MODIFICATIONS

No modification or changes, during or after construction, to the approved Stormwater Management Plan are permitted without written permission from the City of Altoona. If permission is granted, an as-built or record drawing must be submitted to the City of Altoona Stormwater Officer.

MONUMENT

Stone or concrete monument of known coordinates, established by professional land surveyors, and utilized to locate property lines.

MUNICIPAL AUTHORITY

A body politic and corporate created pursuant to the Act of May 2, 1945 (P.L. 382, No. 164), formerly known as the Municipality Authorities Act of 1945.[5]

MUNICIPAL ENGINEER

A professional engineer licensed in the commonwealth of Pennsylvania, duly appointed by the City of Altoona.

MUNICIPALITY

City of Altoona, Blair County, Pennsylvania.

NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)

A program of the United States Government implementing the Federal Clean Water Act through the issuance of permits. In Pennsylvania this program is delegated to the Department of Environmental Protection.

NATIONAL RESOURCES CONSERVATION SERVICE (NRCS)

Natural Resources Conservation Service (NRCS) of the United States Department of Agriculture (USDA) formally known as Soil Conservation Service (SCS).

NATURAL STORMWATER RUNOFF REGIME

A watershed where natural surface configurations, runoff characteristics and defined drainage conveyances have attained the conditions of equilibrium.

NEW CONSTRUCTION

Structures, including any improvements or alterations, for which the necessary permits to start construction were applied for on or after July 24, 2003.

NITRIFICATION

Biological transformation (oxidation) of ammonia nitrogen to nitrite and nitrate forms.

NITROGEN FIXATION

A microbial process in which atmospheric nitrogen gas is incorporated into the synthesis of organic nitrogen.

NOI NOTICE OF INTENT

A request, on a form provided by the Department, for coverage under a general NPDES permit for stormwater discharges associated with construction activities or an E&S permit.

NONDISCHARGE ALTERNATIVE

Environmentally sound and cost-effective BMPs that individually or collectively eliminate the net change in stormwater volume, rate and quality for storm events up to and including the two-year twenty-four-hour storm when compared to the stormwater rate, volume and quality prior to the earth disturbance activities to maintain and protect the existing quality of the receiving surface waters of this commonwealth.

NORMAL POOL ELEVATION

(1)

For bodies of water which have no structural measures to regulate height of water, the height of water at ordinary stages of low water unaffected by drought.

(2)

For structurally regulated bodies of water, the elevation of the spillway, outlet control, or dam crest which maintains the body of water at a specified height.

(3)

The term does not apply to wetlands.

NOTICE OF TERMINATION

A request, on a form provided by DEP, to terminate coverage under a general or individual NPDES permit for stormwater discharges associated with construction activities or other permits under Chapter 102.

NPDES

See National Pollutant Discharge Elimination System.

NPDES PERMIT FOR STORMWATER DISCHARGES ASSOCIATED WITH CONSTRUCTION ACTIVITIES

A permit required for the discharge or potential discharge of stormwater into waters of this commonwealth from construction activities, including clearing and grubbing, grading and excavation activities involving one acre (0.4 hectare) or more of earth disturbance activity or an earth disturbance activity on any portion, part, or during any stage of, a larger common plan of development or sale that involves one acre (0.4 hectare) or more of earth disturbance activity over the life of the project.

NRCS

USDA Natural Resources Conservation Service (formerly SCS).

OBSTRUCTION

Any wall, dam, wharf, embankment, levee, dike, pile abutment, projection, excavation, channel, rectification, culvert, building, fence, stockpile, refuse, fill, structure, or matter in, along, across, or projecting into any channel, watercourse, or flood-prone areas:

(1)

Which may impede, retard, or change the direction of the flow of water either in itself or by catching or collecting debris carried by such water; or

(2)

Which is placed where the flow of the water might carry the same downstream to the damage of life and property.

ON-SITE STORMWATER MANAGEMENT

The control of runoff to allow water falling on a given site to be absorbed or retained on site to the extent that, after development, the peak rate of discharge leaving the site is not significantly different than if the site had remained undeveloped.

OPEN SPACE

That space open from the ground to the sky of which 80% must be vegetative material.

OPEN SPACE RATIO

Total area of open space divided by the total site area in which the open space is located.

OPEN-GRADED MATERIAL

Uniform granular mixture with a narrow distribution of grain sizes. Open-graded material has higher permability than dense graded material.

OPERATOR

A person who has one or more of the following:

(1)

Oversight responsibility of earth disturbance activity on a project site or a portion thereof who has the ability to make modifications to the E&S plan, PCSM plan or site specifications.

(2)

Day-to-day operational control over earth disturbance activity on a project site or a portion thereof to ensure compliance with the E&S plan or PCSM plan.

ORGANIC NITROGEN (ORG-N)

Nitrogen that is bound in organic compounds.

OUTFALL

(1)

The point, location or structure where drainage discharges from a sewer, drain, pipe, or other conduit.

(2)

A point of discharge from a sewer or drain to a water body.

OUTLET

The point at which water discharges from a river, creek or other flow line; lake, tidal basin or drainage depression; or pipe, channel, dam or other hydrologic structure.

OUTLET CONTROL STRUCTURE

The means of controlling the relationship between the headwater elevation and the discharge, placed at the outlet or downstream end of any structure through which water may flow.

PALUSTRINE WETLAND

All nontidal wetlands dominated by trees, shrubs, persistent emergents, emergent mosses, or lichens; and all such tidal wetlands in areas where salinity from ocean - derived salts is below 0.5 parts per thousand.

PCSM

Post construction stormwater management.

PCSM PLAN

A site-specific plan consisting of both drawings and a narrative that identifies BMPs to manage changes in stormwater runoff volume, rate and water quality after earth disturbance activities have ended and the project site is permanently stabilized.

PEAK ATTENUATION STORAGE

The volume set aside within a BMP for the purpose of attenuating the inflow runoff peak rate.

PEAK DISCHARGE

The maximum rate of flow of water at a given point and time resulting from a storm event.

PEAK FLOW

Maximum flow resulting from a storm event.

PENNDOT

The Pennsylvania Department of Transportation.

PENNSYLVANIA AGRONOMY GUIDE

The quick reference book published by the Cooperative Extension Service as a practical guide to gain and forage production, soil fertility management, pest management, and erosion control, with special reference to Pennsylvania conditions.

PENNSYLVANIA EROSION & SEDIMENT POLLUTION CONTROL PROGRAM MANUAL

A primary reference document published by the Pennsylvania Department of Environmental Resources, Bureau of Land and Water conservation, which is used by technically trained persons to prepare erosion and sedimentation control plans for earth moving activities.

PENNSYLVANIA SOIL AND WATER CONSERVATION TECHNICAL GUIDE

A primary reference document published by the United States Department of Agriculture's NRCS, which is used by technically trained persons to plan and apply BMPs.

PERCOLATION

The downward movement under the influence of gravity of water under hydrostatic pressure through the interstices of the rock or soil.

PERCOLATION TEST

A test which evaluates the soil suitability by determining the rate at which effluent can be expected to seep into the soil.

PERENNIAL

Persisting for more than one year. Perennial plant species persist as woody vegetation from year to year or resprout from their rootstock annually.

PERENNIAL STREAM

A body of water flowing in a channel or bed composed primarily of substrates associated with flowing waters and capable, in the absence of pollution or other manmade stream disturbances, of supporting a benthic macro-invertebrate community which is composed of two or more recognizable taxonomic groups of organisms which are large enough to be seen by the unaided eye and can be retained by a United States Standard No. 30 sieve (28 meshes per inch, 0.595 mm openings) and live at least part of their life cycles within or upon available substrates in a body of water or water transport system.

PERFORMANCE STANDARD

A standard which establishes an end result or outcome which is to be achieved but does not prescribe specific means for achieving it.

PERIMETER BMPs

BMPs placed or constructed along the perimeter of an earth disturbance area to prevent runoff from entering the disturbed area, or to capture and treat sediment runoff prior to leaving a disturbed area.

PERMANENT STABILIZATION

Long-term protection of soil and water resources from accelerated erosion.

PERMEABILITY

The ability of rock, soil or other material to transmit a gas or liquid.

PERMIT

Written governmental permission issued by an authorized official, empowering the holder thereof to do some act not forbidden by law but not allowed without such an authorization.

PERMITTEE and/or LICENSEE

A person in whose name a permit and/or license has been issued. This person is also the individual listed as an applicant on the application for a permit and/or license.

PERMITTIVITY (CROSS-PLANE FLOW CAPACITY)

Rate that water will flow freely through a thin layer, such as a geotextile. Equal to the hydraulic conductivity divided by the thickness of the layer. Permittivity is measured in units of inverse time.

PERSON

An individual, partnership, sole proprietorship, public or private association or corporation, firm, trust, company, corporation, estate, municipality, government unit, public utility or any other legal entity whatsoever which is recognized by law as the subject of rights and duties.

PERVIOUS AREA

Any area not defined as impervious.

PHOTIC ZONE

The area of a water body receiving sunlight.

PIEZOMETRIC SURFACE

The surface defined by elevation to which groundwater will rise in a well.

PLAN, FINAL

A complete and exact development plan prepared for official recording as required by statute; a final plat.

PLAN, PRELIMINARY

A development plan in lesser detail than a final plan.

PLAN, SKETCH

An informal optional submission preparatory to the preliminary plan, showing the general intent of the applicant.

PLANNED RESIDENTIAL DEVELOPMENT (PRD)

An area of land controlled by a landowner to be developed as a single entity for a number of dwelling units or combination of residential and nonresidential uses, the development plan for which does not correspond in lot size, bulk, type of dwelling, or use, density, or intensity, lot coverage and required open space to the regulations established in any one district created, from time to time, under the provisions of this chapter.

PLANNING COMMISSION

The Altoona City Planning Commission.

PLANNING DEPARTMENT

Altoona Planning and Community Development Department.

PLUG FLOW

Linear flow along the length of a wetland cell. Ideal plug flow does not involve the dispersion or diffusion of constituents. The flow can be perceived as a series of independent packets of water that do not interact with each other.

PLUNGE POOL

A small permanent pool at either the inlet to a BMP or at the outfall from a BMP. The primary purpose of the pool is to dissipate the velocity of stormwater runoff.

POINT SOURCE

Any discernible, confined, and discrete conveyance, including but not limited to, any pipe, ditch, channel, tunnel, or conduit from which stormwater is or may be discharged and further defined in State regulations at 25 Pa. Code § 92a2.

POLLUTANT

Any contaminant or other alteration of the physical, chemical, biological or radiological integrity of surface water which causes or has the potential to cause pollution as defined in Section 1 of the Clean Streams Law (35 P.S. § 691.1).

POLLUTANT REMOVAL

Removing pollutants by decomposing them or eliminating them from an area or system (e.g., volitize), or rendering nonharmful or unavailable in a soil or medium by means of adsorption, chelation, and similar binding mechanisms.

PORE SPACE

Open space in rock or granular material; also known as interstices.

PPC PLAN—PREPAREDNESS, PREVENTION AND CONTINGENCY PLAN

A written plan that identifies an emergency response program, material and waste inventory, spill and leak prevention and response, inspection program, housekeeping program, security and external factors, and that is developed and implemented at the construction site to control potential discharges of pollutants other than sediment into waters of this commonwealth.

PRECIPITATION

A deposit on the earth of hail, mist, sleet, rain or snow.

PREMISES

Any lot, parcel or tract of land and any building constructed thereon.

PRINCIPAL USE

The primary or predominant uses of any lot or parcel.

PRIVATE ROAD

A legally established right-of-way, other than a street, which provides the primary vehicular access to a lot or lots, and is privately maintained.

PROBABLE MAXIMUM FLOOD (PMF)

The flood that may be expected from the most severe combination of critical meteorological and hydrologic conditions that are reasonably possible in an area. The PMF is derived from the probably maximum precipitation (PMP) as determined on the basis of data obtained from the National Oceanographic and Atmospheric Administration (NOAA).

PROJECT SITE

The specific area of land where any regulated activities in the City are planned, conducted, or maintained.

PROPERTY

A lot, parcel, or tract of land, as well as the building and structures located thereon.

PUBLIC HEARING

A formal meeting held pursuant to public notice by the appropriate agency, intended to inform and obtain public comment, prior to taking action on a matter before the agency.

PUBLIC MEETING

A forum held pursuant to notice under the act of July 3, 1986 (P.L. 388. No. 84), known as the "Sunshine Act."[6]

PUBLIC NOTICE

Notice published pursuant to controlling legislation intended to inform the general public of an activity, usually a hearing or series of meetings.

QUALIFIED PROFESSIONAL

Any person licensed in Pennsylvania or otherwise qualified by law to perform the work required by this chapter.

QUIT CLAIM

A legal document conveying interest, not property, between parties.

QUORUM

A majority of the full authorized membership of a board or agency.

RAINGARDEN

Also called bioretention, a raingarden is an excavated shallow surface depression planted with specially selected native vegetation to treat and capture runoff. Also see bioretention.

RATE OF FLOW

The quantity of water that flows in a certain time under specified conditions.

REASONABLE USE DOCTRINE

A common law principle that no one has the right to use his or her property in a way that deprives others of the lawful enjoyment of their property.

RECEIVING WATER

A water body into which wastewater or treated effluent is discharged.

RECHARGE

Replenishment of groundwater reservoirs by infiltration through permeable soils.

RECORD DRAWINGS

Set of prints of the original facilities showing those changes made during the construction process.

REGULATED ACTIVITY

Any earth disturbance activities or any activity that may affect stormwater runoff. Also any activities that contribute stormwater or nonstormwater discharges to a regulated small MS-4.

REGULATED EARTH DISTURBANCE ACTIVITY

Activity involving earth disturbance subject to regulation under 25 Pa. Code Chapter 92, Chapter 102, or the Clean Streams Law.

REGULATORY FLOOD ELEVATION

The one-hundred-year flood elevation plus a freeboard safety factor of 1 1/2 feet.

RELEASE RATE PERCENTAGE

The watershed factor determined by comparing the maximum rate of runoff from a subbasin to the contributing rate of runoff to the watershed peak rate at specific point of interest.

REPORT

Any letter, review, memorandum, compilation, or similar writing made by any body, board, officer, or consultant other than a solicitor to any other body, board, officer, or consultant for the purpose of assisting the recipient of such report in the rendering of any decision or determination. All reports shall be deemed recommendatory and advisory only and shall not be binding upon the recipient, board, officer, body, or agency, nor shall any appeal lie therefrom. Any report used, received or considered by the body, board, officer, or agency rendering a determination or decision shall be made available for inspection to the applicant and all other parties to any proceeding upon request, and copies thereof shall be provided at cost of reproduction.

RESERVE STRIP

A parcel of ground separating a street from other adjacent properties or from another street, which shall prevent a street from being connected or extended across property lines.

RETENTION POND

A basin, usually enclosed by artificial dikes, that is used to retard stormwater runoff by temporarily storing the runoff and releasing it at a predetermined rate. Retention ponds remain wet once the runoff has been discharged.

RETENTION VOLUME/REMOVED RUNOFF

The volume of runoff that is captured and not released directly into the surface waters of this commonwealth during or after a storm event.

RETURN PERIOD

(1)

The average interval, in years, within which a storm event of a given magnitude can be expected to occur one time. For example, the twenty-five-year return period rainfall would be expected to occur on an average once every 25 years; or stated another way, the probability of twenty-five-year storm occurring in any one year is 0.04 or a 4% chance.

(2)

The average period of time between the occurrence of storms of equal or greater magnitude. The probability that such a storm will occur in any given year is equal to the reciprocal of the return period (e.g. there is a 50% chance that a two-year storm event will occur in any given year, but only a 10% chance that a ten-year storm event will occur).

RIGHT-OF-WAY

(1)

A strip of land that is acquired by reservation, dedication, forced dedication, prescription, or condemnation, and is intended to be occupied by a road, crosswalk, railroad, electric transmission line, oil pipeline, gas pipeline, waterline, sanitary sewer line, storm sewer line, and/or other similar use;

(2)

Generally, the right of one to pass over the property of another.

RIPARIAN

Pertaining to a stream or river. Also, plant communities occurring in association with any spring, lake, river, stream, or creek through which waters flow at least periodically.

RIPARIAN BUFFER

A permanent area of trees and shrubs located adjacent to streams, lakes, ponds, and wetlands.

RIPARIAN CORRIDOR

Narrow strip of land, centered on a stream, that includes the floodplain as well as related riparian habitats adjacent to the floodplain.

RIPARIAN FOREST BUFFER

A type of riparian buffer that consists of permanent vegetation that is predominantly native trees, shrubs and forbs along surface waters that is maintained in a natural state or sustainably managed to protect and enhance water quality, stabilize stream channels and banks, and separate land use activities from surface waters.

RUNOFF

The surface water discharge after a fall of rain or snow that does not enter the soil but runs off or flows over the surface of the land.

RUNOFF CAPTURE DESIGN STORM

Benchmark rainfall event, used to develop criteria for designing the groundwater recharge function of BMPs. The runoff capture design storm is the largest rainfall event from which no appreciable runoff is expected to occur. Complete specification of the storm includes the rainfall depth in inches, return frequency and storm duration. The distribution of rainfall in Pennsylvania is a Type II rainfall distribution. See Section 5.3 of the PA BMP Handbook.

RUNOFF CAPTURE STORAGE

The combined storage volume provided by BMPs on a site for the retention and eventual infiltration of rainfall.

RUNOFF CAPTURE VOLUME

The minimum volume of rainfall that should be retained and completely infiltrated onsite during every storm. It is also equal to the rainfall quantity associated with the runoff capture design storm. The runoff capture volume is conveniently stated as a rainfall volume, in inches, over the area of the site.

RUNOFF CHARACTERISTICS

The surface components of any watershed which affect the rate, amount, and direction of stormwater runoff. These may include, but are not limited to, vegetation, soils, slopes and man-made landscape alterations.

RUNOFF CURVE NUMBER (CN)

A parameter developed by the NRCS which is an indicator of runoff potential. Curve number is related to hydrologic soil group and land use type. The larger the runoff curve number, the greater the percentage of rainfall that will appear as runoff.

RUNOFF PEAK ATTENUATION DESIGN STORM

Benchmark rainfall event, used to develop criteria for the design of runoff peak attenuation BMPs. The design criteria generally requires that the predicted post development peak runoff rate for the selected runoff peak attenuation design storm will not exceed the peak associated with redeveloped condition. Complete specification of the storm includes rainfall depth in inches, return frequency and storm duration. The distribution of rainfall in Pennsylvania is a Type II rainfall distribution. See Section 5.3 of the Handbook.

SANITARY SEWAGE DISPOSAL, COMMUNITY

A sanitary sewage collection system, either publicly or privately owned, in which sewage is carried from individual lots by a system of pipes to a temporary central treatment and disposal plant, generally serving a neighborhood area.

SANITARY SEWAGE DISPOSAL, ON-LOT

Any structure designed to biochemically treat sanitary sewage within the boundaries of an individual lot.

SANITARY SEWAGE DISPOSAL, PUBLIC

A sanitary sewage collection system in which sewage is carried from individual lots by a system of pipes to a central treatment and disposal plant.

SATURATED SOIL

Soil in which the pore space is completely filled with water.

SCREENING

A vegetative material, landscaping, or opaque fencing of sufficient height and density to filter adequately from the adjacent properties light, noise, odors, and the views of the structures and uses on the premises upon which the landscaping, vegetative material, or fence is located.

SEASONALLY HIGH WATER TABLE

Shallow water tables associated with periods of recent high levels of precipitation and/or low levels of evapotranspiration. Frequently determined in the spring.

SEDIMENT

Soils or other solid materials, both mineral and organic, that is in suspension and transported or moved from its site of origin by water as a product of erosion.

SEDIMENT BASIN

A barrier, dam, retention or detention basin located and designed to retain rock, sand, gravel, silt, or other material transported by water.

SEDIMENTATION

The process by which mineral or organic matter is accumulated or deposited by moving water, wind or gravity.

SEEPAGE PIT/SEEPAGE TRENCH

An area of excavated earth filled with loose stone or similar material and into which surface water is directed for infiltration into the ground.

SEMI-PERVIOUS SURFACE

A surface such as stone, rock, concrete or other materials which permits some vertical transmission of water.

SEPTIC TANK

A watertight receptacle which receives sewage or industrial wastes and is designed and constructed to provide for sludge storage, sludge decomposition, separating solids from liquids through a period of detention before allowing the liquid to be discharged.

SETBACK

A distance from the edge of a water body within which intensive development is restricted. Setbacks are established by local regulation for the purpose of maintaining open space next to streams, lakes, and other water bodies. The area within setbacks is frequently used for flood control, recreation, preservation of drinking water supply, and wildlife habitat enhancement.

SETBACK LINE

The line within a property defining the required minimum or maximum distance between any building to be erected and the adjacent property line.

SHADE TREE

A tree in a public place, street, special easement, or right-of-way adjoining a street, as provided in these regulations.

SHEET FLOW

Water flow with a relatively thin and uniform depth.

SHORT CIRCUIT

A faster, channelized water flow route that results in a lower actual hydraulic residence time than the theoretical hydraulic residence time. This may reduce the effectiveness of a BMP.

SIGHT DISTANCE

The required length of roadway visible to the driver of a passenger vehicle at any given point on the roadway when the view is unobstructed by traffic. Sight distance measurements shall be made from a point 10 feet from the edge of a cartway 3 1/2 feet high, to a point 3 1/2 feet above the road surface.

SLOPE

The rise or fall of the land usually measured in percent slope. The percent slope is equal to the rise or fall in feet for a horizontal distance of 100 feet.

Gentle: 0% to 8%.

Rolling: 9% to 15%.

Hilly: 16% to 25%.

Steep: 25% to 40%.

Unbuildable: 41% +.

SOIL CONSERVATION SERVICE (SCS)

The United States Department of Agriculture Soil Conservation Service; now known as the Natural Resources Conservation Service (NRCS).

SOIL PERCOLATION TEST

A field test conducted to determine the suitability of the soil for on-site sanitary sewage disposal facilities by measuring the absorptive capacity of the soil at a given location and depth.

SOIL-COVER-COMPLEX METHOD

A method of runoff computation developed by the Soil Conservation Service, found in Technical Release No. 55, that is based on relating soil type and land use/cover to a runoff parameter called a curve number (CN).

SPILLWAY DESIGN FLOOD (SDF)

Benchmark rainfall event, used to develop criteria for the design of BMPs that incorporate emergency spillways or overflows. Complete specification of the storm includes rainfall depth in inches, return frequency and storm duration. The distribution of rainfall in Pennsylvania is a Type II rainfall distribution. See Section 5.3 of the Handbook.

STABILIZATION

Natural or mechanical treatment of a mass of soil or ground area to increase or maintain its stability and ensure its resistance to erosion, sliding, or other movement.

STAGE DISCHARGE CURVE

A line graph showing the relationship between water depth and outflow from a body of water.

STAGE-AREA CURVE

A line graph showing the relationship between the depth of water and the surface area of a pond, wetland, or lake.

STATE WATER QUALITY REQUIREMENTS

The regulatory requirements to protect, maintain, reclaim, and restore water quality under Title 25 of the Pennsylvania Code Chapters 93 and 96 and the Clean Streams Law.

STORAGE FACILITY

A permanent structure designed to provide space for the storage of materials. Such storage space is usually provided on a rental basis by the owner to the general public. This definition does not include storage incidental to other uses on a property.

STORM FREQUENCY

The average interval in years over which a storm event of a given precipitation volume can be expected to occur.

STORM SEWER

A sewer, system of pipes or conduits, which carries intercepted surface runoff, street water and other drainage but excludes domestic sewage and industrial waste.

STORMWATER

Drainage runoff from the surface of the land resulting from precipitation or snow or ice melt.

STORMWATER (MANAGEMENT) FACILITY

Any facility or structure, natural or man-made that due to its condition, design, or construction conveys, stores, or otherwise affects stormwater runoff. Typical stormwater management facilities whether existing or proposed, open or closed, that retains, detains, holds, carries or transmits stormwater include, but are not limited to: detention and retention basins; open channels; storm sewers; pipes; and infiltration facilities.

STORMWATER COLLECTION SYSTEM

Natural or man-made structures that collect and transport stormwater through or from a drainage area to the point of final outlet, including, but not limited to, any of the following: conduits and appurtenant features, canals, channels, ditches, streams, culverts, streets, and pumping stations.

STORMWATER DRAINAGE SYSTEM

A system of pipes or other conduits which carries intercepted surface runoff, street water and other wash waters, or drainage, but excludes domestic sewage and industrial wastes.

STORMWATER MANAGEMENT PLAN

The plan for managing stormwater runoff adopted by the City of Altoona and Blair County as required by the Stormwater Management Act 167.

STORMWATER MANAGEMENT SITE PLAN

The plan prepared by the developer or his representative indicating how stormwater runoff will be managed at the development site in accordance with this chapter. Stormwater management site plan will be designated as SWM site plan throughout this chapter.

STORMWATER MANAGEMENT/BEST MANAGEMENT PRACTICES

Are abbreviated as BMPs or SWM BMPs throughout this chapter.

STORMWATER OFFICER

Designated employees of the City of Altoona who deal with stormwater or stormwater related issues and/or performs the duties of a Stormwater Officer as defined in this chapter.

STRUCTURE

Any man-made object having an ascertainable stationary location on or in land or water, whether or not directly affixed to the land.

SUBCRITICAL FLOW

The state of flow when the depth is greater than the critical depth.

SUBDIVISION

The division or redivision of a lot, tract or parcel of land by any means into two or more lots, tracts, parcels or other divisions of land, including changes in existing lot lines for the purpose, whether immediate or future, of lease, partition by the court for distribution to heirs or devisees, transfer of ownership or building or lot development; provided, however, that the subdivision by lease of land for agricultural purposes into parcels of more than 10 acres, not involving any new street or easement of access or any residential dwelling, shall be exempted. As defined in the Pennsylvania Municipalities Planning Code, Act of July 31, 1968, P.L. 805, No. 247.

SUBSTANTIAL IMPROVEMENT

(1)

Any reconstruction, rehabilitation, addition, or other improvement of an existing structure, the cost of which equals or exceeds 50% of the market value of the structure before the start of construction of the improvement. This term includes structures which have incurred substantial damage, regardless of the actual repair work performed. The term does not, however, include either:

(a)

Any project for improvement of a structure to correct existing violations of state or local health, sanitary, or safety code specifications which have been identified by the local code enforcement official and which are the minimum necessary to assure safe living conditions; or

(b)

Any alteration of a historic structure, provided that the alteration will not preclude the structure's continued designation as a historic structure.

(2)

Where sexually oriented businesses are concerned, the term "substantial improvement" shall hold the same meaning as the term "substantial enlargement" above.

SUBSTANTIALLY COMPLETED

The condition where a project has been constructed to the point where:

(1)

All basic features have been completed.

(2)

All features necessary for public health, safety and welfare have been installed and are functioning properly.

(3)

No more than 10% of the project cost remains outstanding.

(4)

There is sufficient reason to believe the developer will complete the remaining portions of the project in a timely manner.

SUBSTRATE

Substances used by organisms for growth in a liquid medium. Surface area of solids or soils used by organisms to attach.

SUCCESSION

The temporal changes of plant and animal populations and species in an area that has been disturbed.

SUMP

The area in an inlet from the lowest outlet pipe invert to the bottom of the inlet. This area serves to catch and hold debris in the inlet. Normally varies from 18 to 30 inches.

SUPER CRITICAL FLOW

The state of flow when the depth is less than the critical depth. Transitions between supercritical and subcritical flow may result in turbulence associated with a hydraulic jump.

SURFACE DRAINAGE PLAN

A plan showing all present and proposed grades and facilities for stormwater drainage.

SURFACE INFILTRATION RATE

The rate at which water enters the soil or other porous surface. The measurement of surface infiltration rates requires that the underlying soil be completely saturated and that infiltration occurs by gravity under a unit hydraulic gradient.

SURFACE WATER OF THE COMMONWEALTH

Any and all rivers, streams, creeks, rivulets, runs, impoundments, watercourses, lakes, ponds, springs, and all other bodies of water or channel of conveyance of surface water, or parts thereof within or on the boundaries of the commonwealth.

SURVEYOR

An individual licensed and registered under the laws of the commonwealth of Pennsylvania to engage in the practice of land surveying. A surveyor shall not perform engineering as defined by this chapter, unless the surveyor is also a registered engineer.

SWALE

A low-lying stretch of land which gathers or carries surface water runoff. Usually of a trapezoid shape with gentle side slopes.

TAILWATER CONDITION, MINIMUM AND MAXIMUM

The depth of water in the receiving water body at a structure outfall.

TERRESTRIAL

Living or growing on land that is not normally flooded or saturated.

TOP OF STREAMBANK

First substantial break in slope between the edge of the bed of the stream and the surrounding terrain. The top of streambank can either be a natural or constructed (that is, road or railroad grade) feature, lying generally parallel to the watercourse.

TOPOGRAPHIC MAP

A map showing the elevations of the ground by contours or elevations, including all existing topographic features such as streams, roads, streets, existing facilities, and improvements, as specified herein.

TOPSOIL

Surface soil and subsurface soil which presumably is fertile soil and ordinarily rich in organic matter or humus debris.

TOTAL NITROGEN (TN)

A measure of all organic and inorganic nitrogen forms in a water sample. Functionally, TN is equal to the sum of TKN and NO₃ + NO₂-N.

TOTAL ORGANIC CARBON (TOC)

A measure of the total reduced carbon in a water sample.

TOTAL PHOSPHORUS (TP)

A measure of the total phosphorus in a water sample, including organic and inorganic phosphorus in particulate and soluble forms.

TOTAL SUSPENDED SOLIDS (TSS)

A measure of the filterable matter in a water sample.

TRACTIVE FORCE

The total cross-sectional force experienced by a rigid channel or conduit as a result of channel flow (expressed in units of force per length). This force tends to displace soil particles, rocks and channel liners in the downstream direction and must be resisted by friction or by structural anchors. The tractive force is equal to the unit tractive force multiplied by the wetted perimeter of the conduit.

TRANSITION ZONE

The area between habitats or ecosystems (see ecotones). Frequently, transition zone is used to refer to the area between uplands and wetlands. In other cases, wetlands are referred to as transitional areas between uplands and aquatic ecosystems.

TRANSMISSIVITY (IN-PLANE FLOW CAPACITY)

Rate that water can be made to flow through the cross section of a thin layer or conduit under the influence of a unit hydraulic gradient. Measured as a volumetric rate per unit width (e.g., square feet meters per minute, or gallons per minute per foot). Equal to the hydraulic conductivity times the thickness of the layer or conduit.

TRANSPIRATION

The transport of water vapor from the soil to the atmosphere through growing plants.

TYPE II RAINFALL DISTRIBUTION

Standard NRCS twenty-four-hour rainfall distribution which applies to the state of Pennsylvania. The distribution allocates rainfall as a percentage of total rainfall over discrete time intervals.

UNIFORMITY COEFFICIENT

A measure of the range in particle sizes associated with a granular mixture. Materials with the lowest uniformity coefficients are most uniform. Uniform materials are also called open graded materials. If the uniformity coefficient is less than four or five the material is considered uniform in particle size. The uniformity coefficient is computed as follows:

C_u = (D₆₀/D₁₀)

D₆₀ is the sieve opening size through which 60% of the layer material will pass. D₁₀ is the sieve opening size through which 10% of the layer material will pass.

UNIT TRACTIVE FORSE (OR TRACTIVE STRESS)

The stress (expressed in units of force per area) induced by open channel flow on the bottom and sides of its conduit or channel. This stress is responsible for sediment erosion and the downstream transport of streambed materials. The average unit force acting on a channel cross-section is equal to the product of the unit weight of water, the slope of the channel, and the hydraulic radius of the flow.

UPLAND

An area that is not an aquatic, wetland, or riparian habitat. An area that does not have the hydrologic regime necessary to support hydrophytic vegetation.

USDA

United States Department of Agriculture.

USE

The specific purpose for which land or a building is designed, arranged, intended or for which it is or may be occupied or maintained. The term "permitted use" or its equivalent shall not be deemed to include any nonconforming use.

UTILITY

Any agency that provides the public with electricity, gas, heat, water, sewer, communications, and transportation. Includes public utilities, though not all services included within this definition are public utilities.

VARIANCE

A variance is a modification of the strict terms of zoning regulations where such modification will not be contrary to the public interest and where, owing to physical conditions peculiar to the property and not the result of the action of the applicant, a literal enforcement of the regulations would result in unnecessary and undue hardship.

VARIATION

A variation is a modification of the strict terms of the floodplain regulation where such modification shall not be contrary to the public interest and where, owing to physical conditions peculiar to the property and not the result of the action of the applicant, a literal enforcement of this regulations would result in unnecessary and undue hardship. A variation is similar to a variance but is held to a lower test of hardship.

WAIVER

No waiver will be given for stormwater management. A written variance with regard to fencing around shallow detention ponds can be submitted if it meets the three criteria established in the stormwater ordinance, criteria for detention facilities.

WALL

The vertical exterior surface of a building. Also, the vertical interior surfaces that divide the space within a building into rooms.

WATER QUALITY DESIGN STORM

Benchmark rainfall event, used to develop criteria for the design of water quality BMPs. Water quality design storms are used to size BMPs that are intended to achieve specific quality treatment objectives. Criteria based on water quality storms generally require that the design treatment efficiency be achieved during the water quality design storm and all smaller events. Complete specification of the storm includes rainfall depth in inches, return frequency and storm duration. The distribution of rainfall in Pennsylvania is a Type II rainfall distribution. See Section 5.3 of the PA BMP Handbook.

WATER QUALITY STORAGE

The volume set aside within a BMP to detain storm runoff. The detained water is released over an extended period of time. The water quality storage is frequently expressed as a multiple of the water quality volume.

WATER QUALITY VELOCITY

The maximum flow velocity encountered in a water quality BMP during the course of the water quality design storm.

WATER QUALITY VOLUME

The total volume of runoff which is delivered to the inlet of a water quality BMP during the course of the water quality design storm.

WATER SUPPLY AND DISTRIBUTION SYSTEM, COMMUNITY

A system for supplying and distributing water from a common source to two or more dwellings and other buildings within a subdivision, neighborhood, or whole community, the total system being publicly or privately owned.

WATER SUPPLY AND DISTRIBUTION SYSTEM, ON-LOT

A system for supplying and distributing water to a single dwelling or other building from a source located on the same lot.

WATER SURVEY

An inventory of the source, quantity, yield, use of groundwater and of surface water resources within a municipality.

WATERCOURSE

Any channel of conveyance of surface water having defined bed and banks, whether natural or artificial, with perennial or intermittent flow.

WATERS OF THE COMMONWEALTH

Any and all rivers, streams, creeks, rivulets, impoundments, ditches, water courses, storm sewers, lakes, dammed water, wetlands, ponds, springs, and all other bodies or channels of conveyance of surface and underground water, or parts thereof, whether natural or artificial, within or on the boundaries of the commonwealth of Pennsylvania.

WATERSHED

The entire region or area drained by a river, watercourse, or other surface water whether natural or artificial of the commonwealth. A "designated watershed" is an area delineated by the Pennsylvania DEP and approved by the Environmental Quality Board, for which counties are required to develop watershed stormwater management plans.

WATERSHED STORMWATER MANAGEMENT PLAN

The plan for managing stormwater runoff throughout a designated watershed adopted by Blair County as required by the Pennsylvania Stormwater Management Act.

WATTLES

Fence or barrier constructed of interwoven twigs and branches used to stabilize soil from erosive forces.

WEIR

A device used to control and measure water flow.

WEIR GATE

Water-control device used to adjust water levels and measure flows simultaneously.

WET SWALE

The wet swale also consists of a broad open channel capable of temporarily storing the water quality treatment volume (also a volume-based sizing criteria), but does not have an underlying filtering bed. The wet swale is constructed directly within existing soils and may or may not intercept the water table. Like the dry swale, the water quality volume within the wet swale should be stored for approximately 24 hours.

WETLAND

An area that is inundated or saturated by surface water or groundwater at a frequency, duration, and depth sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions, including swamps, marshes, bogs and similar areas.

WILTING POINT

Quantity of water which will not be removed from soil under normal conditions of evaporation and plant transpiration. Usually measured as the moisture content (by volume) in soil with a capillary tension of 15 bars.

ZONATION

The development of a visible progression of plant or animal communities in response to a gradient of water depth or some other environmental factor.

[1]

Editor's Note: See 53 P.S. § 5601 et seq.

[2]

Editor's Note: See 32 P.S. § 679.101 et seq.

[3]

Editor's Note: See 35 P.S. § 691.1 et seq.

[4]

Editor's Note: See Ch. 362, Floodplain Regulations.

[5]

Editor's Note: See 53 P.S. § 5601 et seq.

[6]

Editor's Note: See 65 Pa. C.S.A. § 701 et seq.

§ 620-11 Stormwater management performance standards.

General standards and requirements.

(1)

Maintenance of natural drainageways. All natural streams, channels, swales, drainage systems and/or areas of surface water concentration shall be maintained in their existing condition unless an alteration is approved by the Altoona City Council. All encroachment activities shall comply with the requirements of Chapter 105, Dam Safety and Waterway Management, and Chapter 106, Floodplain Management, of Title 25 of the Pennsylvania Code, as amended, Rules and Regulations of the Pennsylvania Department of Environmental Protection.

(2)

Diffused or concentrated stormwater flows onto adjacent property shall not be created, increased, decreased, relocated, or otherwise altered without written notification to and acknowledgement from the property owner affected. Such stormwater flows shall be subject to the requirements of this chapter. A stormwater runoff easement from the adjacent property owner(s) to the developer will be acquired, if required.

(3)

Methods of stormwater runoff detention and control.

(a)

The following is a partial listing of detention and control methods which may be utilized in stormwater management systems, if appropriate. The choice of control techniques is not limited to the ones appearing on this list. Please refer to the PA BMP manual and E&S manual for various BMPs and their design standards. Additional techniques not listed in any of these references must be approved by the City of Altoona. Some examples of approved techniques include but are not limited to:

[1]

Decreased impervious area covered.

[2]

Routed flow over grass.

[3]

Grassed channels and vegetated strips or areas.

[4]

Where soil conditions permit, roof drain seepage pits, seepage trenches or other infiltration structures.

[5]

Porous pavement and concrete lattice-block surfaces.

[6]

Cisterns and underground reservoirs.

[7]

Detention and retention basins, including biodetention/bioretention.

[8]

Parking lot ponding.

[9]

Rooftop storage.

(b)

The City may, after consultation with DEP, approve measures for meeting the state water quality requirements other than those in this chapter, provided that they meet the minimum requirements of, and do not conflict with state law including, but not limited to, the Clean Streams Law.[1]

[1]

Editor's Note: See 35 P.S. § 691.1 et seq.

(4)

All proposed stormwater control measures shall be evaluated according to the following performance standards:

(a)

Any developer, landowner and/or any person engaged in the alteration or development of land which may affect stormwater runoff characteristics shall implement such measures as are reasonably necessary to promote public health, safety, and welfare on the property and adjacent lands and to control the rate, volume, and quality of the stormwater runoff. Such measures shall include such actions as are required:

[1]

To assure that the peak runoff volume and maximum rate of stormwater runoff from the two-, ten-, twenty-five-, and one-hundred-year storms is no greater after development than prior to development activities.

[2]

To manage the quantity, velocity and direction of resulting stormwater runoff in a manner which adequately protects health and property from possible injury.

[3]

To assure no adverse effect will occur to any adjacent or abutting property.

(b)

The stormwater management plan for the development site shall consider all the stormwater runoff flowing over the site, regardless of where the runoff initiates.

(c)

No discharge of nonstormwater or any toxic materials shall be permitted into any stormwater management system. Where required by federal and state regulation, the landowner or developer shall be responsible for obtaining an NPDES permit for stormwater discharges.

(d)

All land disturbance activities shall be conducted in such a way as to minimize any erosion and sedimentation. Measures to control erosion shall, at a minimum, meet the standards of the County Conservation District and the rules and regulations of the Pennsylvania Department of Environmental Protection.

(e)

No site shall be subdivided by the property owner/applicant which allows one or more parcels to not meet Subsection A(1) of this section or any other requirement of this section, unless approved in writing by the City.

(f)

For all regulated activities, stormwater management BMPs shall be designed, implemented, operated, and maintained to meet the purposes and requirements of this chapter and to meet all requirements under Title 25 of the Pennsylvania Code, the Clean Streams Law, and the Stormwater Management Act. Various BMPs and their design standards are listed in the BMP Manual.

(g)

All stormwater facilities shall be constructed to minimize accelerated erosion and resulting sediment pollution. Measures to control erosion and resulting sediment pollution shall, at a minimum, meet the standards or 25 Pa. Code, Chapter 102, Erosion and Sediment Pollution Control, and the latest edition of the Erosion and Sediment Pollution Control Manual.

(h)

Be designed so that the construction of basins within the one-hundred-year floodplain are avoided wherever possible. But where unavoidable, the situation must be consistent with the City's Floodplain regulations and 25 Pa. Code, Chapter 106, Floodplain Management.

(i)

Be designed by a licensed professional, trained and experienced in stormwater management. The design, and installation of the control measures are the responsibility of the developer.

(j)

Any stormwater management facility that is located in or adjacent to waters of the commonwealth or wetlands shall be subject to approval by DEP through the joint permit application process or where deemed appropriate by DEP, the general permit process.

(k)

Any stormwater facilities that is located on a state highway right-of-way or connected to stormwater facilities within the state right-of-way shall be subject to PennDOT approval and permitting.

(l)

Connection of roof drains to streets, storm sewers, or roadside ditches should be avoided. Promote infiltration/percolation of stormwater where it is feasible to do so. When it is more advantageous to connect to streets, ditches, or storm sewers, it shall be permitted on a case by case basis by the City.

(m)

Preparation and implementation of an approved stormwater management plan is required. No activities shall commence until the City issues written approval of a SWM plan, which demonstrates compliance with the requirements of this chapter.

(n)

SWM site plans approved by the City in accordance with this chapter shall be on site throughout the duration of the construction or regulated activity.

§ 620-12 Stormwater management technical standards.

Stormwater runoff, volume, and quality control standards.

(1)

Runoff rates. There shall be no increase in the peak rate of stormwater runoff discharge from the two-, five-, ten-, twenty-five-, fifty-, and one-hundred-year storms for any activity covered by this article following the completion of the activity (post-development conditions) over the rate that would have occurred from the entire development or land parcel prior to the activity (predevelopment conditions). This criteria shall apply to the total activity even if the activity is to take place in stages.

(a)

Areas not covered by a release rate map from an approved Act 167 stormwater management plan: post development discharge rates shall not exceed the predevelopment discharge rates for the two-, five-, ten-, twenty-five-, fifty-, and one-hundred-year twenty-four-hour storms. If it is shown that the peak rates of discharge indicated by the postdevelopment analysis are less than or equal to the peak rates of discharge indicated by the predevelopment analysis for the two-, five-, ten-, twenty-five-, fifty-, and one-hundred-year twenty-four-hour storms, then the requirements of this section have been met. Otherwise, the applicant shall provide additional controls as necessary to satisfy the peak rate of discharge requirement.

(b)

Areas covered by a release rate map from an approved Act 167 stormwater management plan: for the two-, five-, ten-, twenty-five-, fifty-, and one-hundred-year storms, the postdevelopment peak discharge rates will follow the applicable approved release rate maps. For any areas not shown on the release rate maps, the postdevelopment discharge rates shall not exceed the predevelopment discharge rates.

(c)

Off site areas which drain through a proposed development site are not subject to the control standard when determining allowable peak runoff rates. However, on-site drainage facilities shall be designed to safely convey off-site flows through the development site. The preceding standard is at the discretion of the Stormwater Officer. Onsite runoff rates will be per Subsection A(1) of this section.

(d)

Where the site area to be impacted through a proposed development activity differs significantly from the total site area, only the proposed impact area shall be subject to the runoff criteria; however, the entire site will be considered for total runoff.

(2)

Storm frequencies.

(a)

Stormwater management facilities on all development sites shall control the peak stormwater rates of discharge for the two-, five-, ten-, twenty-five-, fifty-, and one-hundred-year storm frequencies. At a minimum, the United States Department of Agriculture's Natural Resources Conservation Service (USDA NRCS) twenty-four-hour, Type II Rainfall Distribution or the National Oceanic and Atmospheric Administration (NOAA) Precipitation-Frequency Atlas of the United States, Atlas 14, Volume 2, version 3.0 shall be used for analyzing stormwater runoff for both pre- and post-development conditions. The twenty-four-hour total rainfall for these storm frequencies in the watershed are:

	Storm Frequency	Rainfall Depth (inches)
	2-year	2.7
	5-year	3.3
	10-year	3.9
	25-year	4.7
	50-year	5.3
	100-year	6.1

(b)

If at any time, the United States Department of Agriculture Natural Resources Conservation Service (USDA NCRS) or the National Oceanic and Atmospheric Administration (NOAA) updates the rainfall depths for these storm frequencies, the new data shall be used.

(3)

Volume control. The low impact development practices provided in the BMP Manual shall be utilized for all regulated activities to the maximum extent practicable. Water volume controls shall be implemented using the design storm method in Subsection A or the simplified method in Subsection B. For regulated activity areas equal or less than one acre that do not require hydrologic routing to design the stormwater facilities, this chapter establishes no preference for either methodology.

(a)

The Design Storm Method (CG-1 in the BMP Manual) is applicable to any size of regulated activity. This method requires detailed modeling based on site conditions.

[1]

Do not increase the post development total runoff volume for all storms equal to or less than the two-year twenty-four-hour precipitation duration.

[2]

For modeling purposes:

[a]

Existing (predevelopment) non-forested pervious areas must be considered meadow in good condition unless the natural ground cover generates a lower curve number (i.e., forest).

[b]

Twenty percent of existing impervious area, when present, shall be considered meadow in good condition in the model for existing conditions.

(b)

The simplified method (CG-2) in the BMP manual provided below is independent of site conditions and should be used if the design storm method is not followed. This method is not applicable to regulated areas greater than one acre or for projects that require hydrologic routing to design stormwater storage facilities. For new impervious surfaces:

[1]

Stormwater facilities shall capture at least the first two inches of runoff from all new impervious surfaces.

[2]

At least the first one inch of runoff from new impervious surfaces shall be permanently removed from the runoff flow i.e., it shall not be released into the surface waters of the commonwealth. Removal options include reuse, evaporation, transpiration, and infiltration.

[3]

Whenever possible, infiltration facilities should be designed to accommodate infiltration of the entire permanently removed runoff; however, in all cases at least the first 0.5 inch of the permanently removed runoff should be infiltrated.

(4)

Calculation methods.

(a)

Development sites. For the purpose of computing peak flow rates and runoff hydrographs from development sites, calculations shall be performed using one of the following: United States Department of Agriculture's Natural Resources Conservation Service (USDA NRCS) publications, Technical Release (TR) 55 or 20, HEC I or Penn State Runoff Model (PSRM) or Modified Rational Method. Under special circumstances, other computation methods may be used, subject to the approval of the City of Altoona. The designer must list or identify the method and resources used in the stormwater design report or narrative.

(b)

Stormwater collection/conveyance facilities. For the purposes of designing storm sewers, open swales and other stormwater runoff collection and conveyance facilities, the Rational Method or other method as approved by the City of Altoona may be applied. Current rainfall intensities for design should be obtained from the United States Department of Agriculture's Natural Resources Conservation Service, NOAA, or the Pennsylvania Department of Transportation rainfall charts (the more restrictive of the three shall apply).

(c)

Routing of hydrographs through detention/retention facilities for the purpose of designing those facilities shall be accomplished using the recognized reservoir routing methods, subject to the approval of the Stormwater Officer.

(d)

Predevelopment conditions. Predevelopment conditions shall be assumed to be those which exist on any site prior to commencing any development activities. Natural Resources Conservation Service (NRCS, formerly "SCS") runoff curve numbers selected for use in the calculations shall accurately reflect existing conditions subject to the approval of the City of Altoona. The runoff curve number is based on the area's hydrologic soil group, land use, treatment and hydrologic condition. References, such as those from the USDA indicate the runoff curve numbers for characteristic land cover descriptions and a hydrologic soil group. See Appendix A for Table 2-2a[1] from SCS TR-55. At its discretion, the City of Altoona may direct that hydrologic conditions for all areas with pervious cover (i.e., fields, woods, lawn areas, pastures, cropland, etc.) shall be assumed to be in "good" condition, and the lowest recommended Natural Resources Conservation Service (NRCS) runoff curve number (CN) shall be applied for all pervious land uses within the respective range for each land use and hydrologic soil group. Use CN values for specific conditions, i.e. grass, paved area, gravel, dirt, etc. Average values, such as those for urban or residential districts, are discouraged and their use prohibited unless necessary. Impervious cover shall include, but not be limited to, any roof, parking, or driveway areas, and any new streets and sidewalks. Any areas designed to initially be aggregate, gravel or crushed stone shall be considered impervious (use the highest CN value for Impervious) for the purposes of the stormwater design and these criteria. The Stormwater Officer has the authority to require that computed existing runoff rates be reconciled with field observations and conditions. If the designer can substantiate through actual physical calibration that more appropriate runoff values should be used at a particular site, then appropriate variations may be made upon review and recommendations of the Stormwater Officer. Calibration shall require detailed gauge and rainfall data for the particular site in question.

[1]

Editor's Note: Said appendix is included as an attachment to this chapter.

(e)

As required by DEP's Pennsylvania Stormwater Best Management Practices Manual's model for existing conditions, all redevelopment sites must consider 20% of existing impervious surfaces to be meadow in good condition for predevelopment calculations.

(f)

Calculations for any development site one acre or less should be calculated in square feet. Calculations for sites greater than on acre may be calculated in acres.

(5)

Stormwater quality management requirements.

(a)

Applicability. In addition to the other performance standards and design criteria requirements of this article, the land developer shall implement the following water quality requirements unless otherwise exempted by the provisions of this article.

(b)

Water quality requirements.

[1]

No regulated activities within the City of Altoona shall commence until approval by the City of Altoona of a plan which demonstrates compliance with state water quality requirements after construction is complete.

[2]

Stormwater best management practices must be designed, implemented, and maintained to meet all applicable state water quality requirements in effect at the time of design/submission.

[3]

To control postconstruction stormwater impacts from regulated activities, state water quality requirements can be met by BMPs, including site design, which provide for replication of preconstruction stormwater infiltration and runoff conditions, so that postconstruction discharges do not degrade the physical, chemical, or biological characteristics of the receiving waters. This may be achieved by, but not limited to, the following:

[a]

Infiltration: replication of preconstruction stormwater infiltration conditions.

[b]

Treatment: use of water quality treatment BMPs to ensure removal of the chemical and physical pollutants from the stormwater runoff.

[c]

Stream bank and streambed protection: management of volume and rate of postconstruction stormwater discharges to prevent physical degradation of receiving waters (e.g., from scouring).

[4]

Provisions for the assurance of long-term operations and maintenance of BMPs must be provided in accordance with § 5.

[5]

Acceptable stormwater management BMPs must be provided to manage the net increase in stormwater runoff volume from the land development activities from a two-, ten-, twenty-five-, and one-hundred-year/twenty-four-hour frequency storm. A two-year/twenty-four-hour frequency storm equates to 2.6 inches of rainfall occurring over a twenty-four-hour period.

[6]

Evidence of any necessary permit(s) for earth disturbance activities from the appropriate DEP or soil conservation district office must be provided to the City of Altoona.

(c)

BMP selection criteria.

[1]

BMP selection and application shall be in accordance with guidance provided in the BMP manuals published by the Department of Environmental Protection. In selecting the appropriate BMPs or combinations thereof, the land developer shall consider the following:

[a]

Total contributing area.

[b]

Permeability and infiltration rate of the site soils.

[c]

Slope and depth to bedrock and other applicable geological features.

[d]

Seasonal high water table.

[e]

Proximity to building foundations and wellheads.

[f]

Erodibility of soils.

[g]

Land availability and configuration/slope of the topography.

[2]

The following additional factors should be considered when evaluating the suitability of the BMPs used to control water quality at a given development site:

[a]

Peak discharge and required volume control.

[b]

Soil or stream bank erosion.

[c]

Efficiency of the BMPs to mitigate potential water quality problems.

[d]

The volume of runoff that will be effectively treated.

[e]

The nature of the pollutant(s) being removed.

[f]

Maintenance requirements.

[g]

Recreation value.

[h]

Enhancement of aesthetics and property values.

[3]

Refer to Appendix B for worksheets 11,12, and 13 from the PA Stormwater BMP manual.

Design criteria for stormwater management controls.

(1)

General criteria.

(a)

Applicants may select runoff control techniques, or a combination of techniques, which are most suitable to control stormwater runoff from the development site. All controls shall be subject to approval of the Stormwater Officer. The Stormwater Officer may request specific information on design and/or operating features of the proposed stormwater controls in order to determine their suitability and adequacy in terms of the standards of this chapter.

(b)

The applicant should consider the effect of the proposed stormwater management techniques on any special soil conditions or geological hazards which may exist on the development site. In the event such conditions are identified on the site, the Stormwater Officer may require in-depth studies by a competent geotechnical engineer. Not all stormwater control methods may be advisable or allowable at a particular development site.

(c)

In developing a stormwater management plan for a particular site, stormwater controls shall be selected according to the following order of preference:

[1]

Infiltration and/or treatment of runoff on site.

[2]

Flow attenuation by use of open vegetated swales and natural depressions.

[3]

Stormwater detention/retention structures.

(d)

Infiltration practices shall be used to the extent practicable to reduce volume increases and promote groundwater recharge. A combination of successive practices may be used to achieve the applicable minimum control requirements. Justification shall be provided by the applicant for rejecting each of the preferred practices based on actual site conditions.

(2)

Criteria for infiltration systems.

(a)

Infiltration systems shall be sized and designed based upon local soil and groundwater conditions as well as subsurface geological features. Provide percolation test results and in-depth studies by a competent Geotechnical Engineer.

(b)

Infiltration BMPs should be spread out, made as shallow as practicable, and located to maximize use of natural on-site infiltration features while still meeting the other requirements of this chapter. Infiltration systems greater than three feet deep shall be located a minimum of 10 feet from basement walls.

(c)

Infiltration systems shall not be used to handle runoff from commercial or industrial working or parking areas. This prohibition does not extend to roof areas which are demonstrated to be suitably protected from the effects of the commercial/industrial activities. Consideration and approval may be given to commercial infiltration systems on a case-by-case basis, provided the stormwater is clean and/or is treated in a water quality device prior to being infiltrated. Pretreated water will meet the requirements of the Pennsylvania Department of Environmental Protection.

(d)

Infiltration systems once installed may not receive construction traffic which could affect the design and/or working integrity of the system.

(e)

Infiltration systems may not receive runoff until the entire drainage area to the system has received final stabilization.

(f)

The stormwater infiltration facility design shall provide an overflow system with measures to provide a nonerosive velocity of flow along its length and at the outfall.

(g)

Roof drain stormwater infiltration systems shall provide a volume of at least one cubic foot for every two square feet of roof surface.

(3)

Criteria for attenuation facilities.

(a)

If flow-attenuation facilities are employed to assist in the control of peak rates of discharge, their effects must be quantified using the NRCS (Natural Resources Conservation Service) Technical Release (TR) 55, Urban Hydrology for Small Watersheds, or other approved method. The effects of the flow-attenuation facilities on travel time should be reflected in the calculations.

(b)

Flow-attenuation facilities such as swales and natural depressions should be properly graded to ensure positive drainage and avoid prolonged ponding of water.

(c)

Swales shall be properly vegetated and stabilized or otherwise lined to prevent erosion.

(d)

Swales shall be designed according to the recommendations contained in the commonwealth of Pennsylvania's Erosion and Sediment Pollution Control Program Manual and the Stormwater Best Management Practices Manual.

(e)

Swales, ditches, etc., that are equal to or in excess of 15% grade shall be rock-lined or designed with an approved energy dissipater. Rock lining may be required regardless of the slope or for any reason by the Stormwater Officer.

(4)

Criteria for stormwater detention facilities.

(a)

All detention facilities including wet ponds, rain gardens, bio-retention areas, etc. will be per the design criteria in the Pennsylvania Stormwater Best Management Practices Manual and shall be equipped with outlet structures to provide discharge control for the four designated storm frequencies. Provisions shall also be made to safely pass the post-development one-hundred-year storm runoff with a minimum of one foot of freeboard without damaging or impairing the continued function of the facilities. Should any stormwater management facilities qualify as a dam under Pennsylvania Department of Environmental Protection Chapter 105, the facility shall be designed in accordance with those regulations and meet the regulations concerning dam safety.

(b)

Shared-storage facilities which provide detention of runoff for more than one development site within a single sub area are encouraged wherever feasible, and provided such facilities meet the criteria contained in this section. In addition, runoff from the development sites involved shall be conveyed to the facility in a manner that avoids adverse impacts (such as flooding or erosion) to channels and properties located between the development site and the shared-storage facilities.

(c)

Where detention facilities will be utilized, multiple use facilities, such as wetlands, lakes, ballfields or similar recreational/open space uses are encouraged wherever feasible, subject to the approval of the City of Altoona and compliance with Pennsylvania Department of Environmental Protection Chapter 105 Regulations.

(d)

Other considerations which should be incorporated into the design of the detention facilities include:

[1]

Stormwater system shall be the first thing constructed unless otherwise noted in writing by the City.

[2]

Inflow and outflow structures shall be designed and installed to prevent erosion, and bottoms of impoundment-type structures should be protected from soil erosion.

[3]

Control and removal of debris both in the storage structure and in all inlet or outlet devices shall be a design consideration.

[4]

Inflow and outflow structures, pumping stations, and other structures shall be designed and protected to minimize safety hazards.

[5]

The water depth at the perimeter of a storage pond should be limited to that which is safe for children. Current chapters require restriction of access by use of fencing, refer to [10] below. Further restriction of access (i.e. walls, etc.) may be necessary depending on the location of the facility and/or the maximum depths of water.

[6]

Side slope of storage ponds shall not exceed a ratio of 2 1/2 to one (2.5:1) horizontal-to-vertical dimension.

[7]

Landscaping shall be provided for the facility which harmonizes with the surrounding area. Native (noninvasive) woody and herbaceous vegetation and tree planting is encouraged for shading, water quality, and site enhancement.

[8]

Facility shall be located to facilitate maintenance, considering the frequency and type of equipment that will be required. All detention ponds shall be provided with a suitable access road with a minimum width of 12 feet located within a twenty-foot minimum easement.

[9]

Bottoms of detention basins should be graded with sufficient slope to provide positive surface drainage. A sub-drainage system may be required, depending on the location of the pond bottom relative to groundwater levels. Note: This is not to be interpreted as an exclusion of wet ponds, bioretention areas, and basins with forebays, islands, or other permitted stormwater structures that may have irregular bottoms as a design feature.

[10]

Fencing shall be provided around the entire perimeter for all above ground retention/detention stormwater facilities. The height of the fence shall be a minimum of six feet. A double gate having a minimum width of 12 feet shall be installed to provide access to the stormwater detention basin. A written variance may be requested/submitted if the proposed facility meets the following three criteria:

[a]

Maximum possible ponding depth of 12 inches or less.

[b]

Maximum side slopes of the facility are three horizontal to one vertical (3:1).

[c]

Calculations are provided to demonstrate the facility will dewater within 48 hours of a storm event.

[11]

Where any tract is traversed by a watercourse, drainageway, channel, stream, etc., there shall be provided a drainage easement, conforming substantially with the line of such watercourse, drainageway, channel or stream, of such width as will be adequate to: preserve the unimpeded flow of natural drainage; or encompass the widening, deepening, improving or protecting of such drainage facilities. An existing watercourse, drainageway, channel, or stream location shall be changed only when approved by the City of Altoona.

[12]

Natural drainageways shall be utilized to the maximum extent possible in carrying stormwater runoff.

[13]

Erosion and sedimentation. All earthmoving activities shall be conducted in such a way as to minimize accelerated erosion and resulting sedimentation. Measures to control erosion and sedimentation shall at a minimum meet the standards of the Conservation District and Chapter 102 (Erosion and Sedimentation Control) of Title 25 Pa. Code, Rules and Regulations of the Pennsylvania Department of Environmental Protection, and Article XV of Part 4 of this chapter.

[14]

All structures are to be located and sited to minimize the risk of flooding of said structures. When the elevation of any entrance, including windows, to a structure, whether existing or to be constructed on a site, is lower than the elevation of the public cartway serving that site, the site plan which includes construction or alteration of the structure(s) and/or grading shall show a method to minimize the risk of flooding from drainage moving from the public cartway.

[15]

In areas underlain with limestone geology, detention and retention ponds shall be lined. If at any time a sinkhole develops in a pond or channel, a lining shall be required to be installed by the developer. Stormwater resulting from land development shall not be discharged into sinkholes.

[16]

Methods of stormwater detention/retention and control which are designed to result in the surface accumulation of ponding may be enclosed, at the discretion of the City. Said enclosure shall be designed to restrict access to unauthorized individuals only, while providing maintenance capabilities.

[17]

Any stormwater management facility required or regulated by this chapter shall be designed to provide an emergency spillway to handle flow up to and including the one-hundred-year post-development conditions. The height of embankment must be set as to provide a minimum one foot of freeboard above the maximum pool elevation computed when the facility functions for the one-hundred-year post-development inflow. However, criteria for design and construction of stormwater management facilities are not the same criteria that are used in permitting of dams under the Department of Environmental Protection's Dam Safety Program. Depending upon the physical characteristics of a dam, a dam permit may be required, and the design will have to meet the provisions of the Dam Safety and Encroachments Act, as amended, Chapter 105 of Title 25 of the Pennsylvania Code. Depending on the physical characteristics of a dam, the design could require that anywhere from a fifty-year to a "probable maximum flood" storm event be considered.

[18]

A percolation test may be required after an evaluation of the soil profile indicates that soils may be suitable for an on-lot stormwater runoff control system. In accordance with DEP requirements, applicable geotechnical information, percolation test results, infiltration test pit results, test location map, etc., will be submitted along with the stormwater plans and/or narratives for stormwater review. Refer to the Pennsylvania Stormwater Best Management Practices Manual for test criteria.

[19]

Construction criteria for stormwater management facilities shall be in accordance with the approved plans and accompanying specifications.

[20]

Cut-and-fill slopes shall be no steeper than two horizontal to one vertical feet, unless substantiated data justifying steeper slopes, presented by a professional engineer, are submitted to and approved by the City of Altoona. If fill is used, it shall:

[a]

Consist of soil or small rock materials only. Sanitary landfills shall not be permitted.

[b]

Be compacted to provide the necessary permeability and resistance to erosion, scouring, setting or settlement.

[c]

Be used to the extent to which it does not adversely affect adjacent properties.

[d]

Meet the requirements of Standards Specifications — Form A, General Technical Provisions, Section 1, Earthwork, of the City of Altoona.[2]

[2]

Editor's Note: Said standards and specifications are on file in the City's offices.

Design criteria for collection/conveyance facilities.

(1)

Criteria for collection and conveyance facilities: All stormwater runoff collection or conveyance facilities, whether storm sewers, open or closed channels, or other shall be designed in accordance with the following criteria:

(a)

All sites shall be graded to provide positive drainage away from and around structures. This will help in preventing any potential flooding damage. If not provided, the City may require a grading and drainage plan.

(b)

Lots located on the high side of streets shall extend roof, French drains, and other stormwater discharges to the curb line and/or storm sewer (if applicable). Low side lots shall extend roof, French drains, and other stormwater discharges to a stormwater collection/conveyance/control system or natural watercourse in accordance with the approved stormwater management plan for the development site.

(c)

Collection/conveyance facilities should not be installed parallel and close to the top or bottom of a major embankment to avoid the possibility of failing or causing the embankment to fail.

(d)

All collection/conveyance facilities shall be designed to convey the twenty-five-year storm peak flow rate from the contributing drainage area and to carry it to the nearest suitable outlet such as a stormwater control facility, curbed street, storm sewer or natural watercourse without damage to the drainage structure or roadway, with runoff from the twenty-five-year design storm at a minimum one foot of freeboard measured below the lowest point along the top of the roadway. Roadway crossings located within designated floodplain areas must be able to convey runoff from a one-hundred-year design storm with a minimum of one-and-one-half-foot freeboard measured below the lowest point along the top of the roadway.

[1]

When it can be shown that, due to topographic conditions, natural drainageways on the site cannot adequately provide for drainage, open channels may be constructed conforming substantially to the line and grade of such natural drainageways. Work within natural drainageways shall be subject to approval by Pennsylvania Department of Environmental Protection through the joint permit application process or, where appropriate, by the Pennsylvania Department of Environmental Protection through the general permit process.

(e)

Where drainage swales or open channels are used, they shall be suitably lined to prevent erosion and designed with energy dissipaters to avoid excessive velocities. Swales, ditches, etc. that are equal to or in excess of 15% grade shall be rock-lined or designed with an approved energy dissipater. Rock lining may be required regardless of the slope or for any reason by the Stormwater Officer. The minimum size rock shall be R4.

(f)

Stormwater drainage systems shall be provided in order to permit unimpeded flow along natural watercourses, except as modified by stormwater management facilities or open channels consistent with this chapter.

(g)

Existing points of concentrated drainage that discharge onto adjacent property shall not be altered without permission of the altered property's owner(s) and shall be subject to any applicable discharge criteria specified in this chapter.

(h)

Areas of existing diffused drainage discharge shall be subject to any applicable discharge criteria in the general direction of existing discharge, whether proposed to be concentrated or maintained as diffused drainage areas, except as otherwise provided by this chapter. If diffused flow is proposed to be concentrated and discharged onto adjacent property, the developer must document that adequate downstream conveyance facilities exist to safely transport the concentrated discharge or otherwise prove that no erosion, sedimentation, flooding, or other harm will result from the concentrated discharge.

(i)

Where a development site is traversed by watercourses, drainage easements shall be provided conforming to the line of such watercourses. The terms of the easements shall prohibit excavation, the placing of fill or structures, and any alterations that may adversely affect the flow of stormwater within any portion of the easement. Maintenance within the easement shall be required. Mowing of vegetation will be subject to approval by the Stormwater Officer.

(j)

Any stormwater management facilities regulated by this article that would be located in or adjacent to waters of the Commonwealth of Pennsylvania or wetlands shall be subject to approval by the Pennsylvania Department of Environmental Protection through the joint permit application process or, where deemed appropriate by the Pennsylvania Department of Environmental Protection, the general permit process. When there is a question whether wetlands may be involved, it is the responsibility of the developer or his or her agent to show that the land in question cannot be classified as wetlands; otherwise, approval to work in the area must be obtained by the Pennsylvania Department of Environmental Protection.

(k)

Any stormwater management facilities regulated by this Article that would be located on federal or state highway rights-of-way shall be subject to approval by the appropriate governing agency having jurisdiction.

(l)

In order to promote overland flow and infiltration/percolation of runoff where it is advantageous to do so, roof drains must not be connected to streets, sanitary or storm sewers, or roadside ditches. When it is more advantageous to connect directly to streets or storm sewers, then it shall be permitted on a case-by-case basis by the Stormwater Officer.

(m)

Stormwater drainage, including roof drains, from any new construction shall not be connected to the sanitary sewer system.

(2)

Criteria for proposed storm sewers: Wherever storm sewers are proposed to be utilized, they shall comply with the following criteria:

(a)

Where practical, designed to traverse under seeded and planted areas. If constructed within 10 feet of road paving, walks or other surfaced areas, storm sewers or drains shall have the minimum allowable trench and maximum compaction of backfill to prevent settlement of the superimposed surface or development.

(b)

Preferably installed after excavating and/or filling of the area to be traversed is completed, unless the storm sewer is installed in the original ground with a minimum of three feet of cover and/or adequate protection is provided during the fill construction. At no time may additional fill be added over the pipe thereby increasing the amount of cover over the designed elevations. This restriction of adding additional fill over the pipe applies to existing storm sewers and piping as well as proposed.

(c)

Storm sewers shall be designed:

[1]

With cradles, when traversing fill areas of indeterminate stability or when required due to lack of vertical clearance between utilities.

[2]

With anchors, when slope gradient exceeds 20%.

[3]

With encasement and/or special backfill requirements as otherwise directed by the Stormwater Officer and/or backfilled with PennDOT 2A coarse aggregate when traversing under a paved area and/or shoulder area.

[4]

To include a gas trap at the point of discharge; his standard is applicable only when tying into a combined sewer system.

(d)

Designed to adequately handle the anticipated stormwater flow and be economical to construct and maintain. The minimum pipe size shall be 15 inches in diameter in a City right-of-way.

(e)

Drain pipe, trenching, bedding and backfilling requirements shall conform to the requirements of the City of Altoona and/or applicable Pennsylvania Department of Transportation Specifications, Form 408.

(f)

All corrugated metal pipe shall be polymer-coated, with asbestos bonding and paved inverts where prone to erode. All plastic pipe shall be double wall. Pipe within a municipal right-of-way shall be reinforced concrete pipe with a minimum diameter of 15 inches, unless otherwise directed or approved by the Stormwater Officer.

(g)

Storm inlets shall conform to the requirements of the City of Altoona and/or applicable Pennsylvania Department of Transportation Specifications and Roadway Construction (RC) Standards. Storm inlets and structures shall be designed to be adequate, safe, self-cleaning and unobtrusive and consistent with City and PennDOT standards. At a minimum, storm inlets shall be two feet by four feet in size (inside measurements) with a minimum sump of 1 1/2 feet and a maximum sump of three feet. A minimum sump of one foot may be approved by the Stormwater Officer due to extreme depth or extenuating circumstances on a case-by-case basis. To encourage infiltration, leaching-type catch basins are allowed, subject to design approval.

(h)

Appropriate style grates shall be designed for all catch basins, stormwater inlets and other entrance appurtenances. All inlet grates in paved areas must be bicycle safe. Where practical or appropriate, provide pre-cast or after-market medallions with wording such as "only rain in the drain," "drains to the stream," "stormwater only," "no dumping," etc.

(i)

All manholes to be a minimum four feet in diameter and comply with the standards of the City of Altoona and/or applicable Pennsylvania Department of Transportation Specifications and Roadway Construction (RC) Standards. Manholes located in roadways and parking areas shall be designed so that the top of the frame and lid shall be at finished grade and sloped to conform to the slope of the finished grade. Top castings of structures located in roads or parking areas shall be manufactured and installed to preclude movement or "rattling." Manholes located in earthen areas shall extend a minimum of 1 1/2 feet above the earth finished grade.

(j)

Where a proposed storm sewer connects with an existing storm sewer system and there will be an increase in the rate of flow of stormwater into the downstream system, the applicant shall demonstrate that sufficient capacity exists in the downstream system to handle the additional rate of flow.

(k)

Storm sewer outfalls and culverts shall be equipped with either reinforced concrete headwalls or pipe end sections and energy dissipation devices to prevent erosion and conform to applicable requirements of the Pennsylvania Department of Environmental Protection for stream encroachments (Chapter 105 of Title 25 Pa. Code Department of Environmental Protection Rules and Regulations).

(l)

Any connection to the City storm sewer system, whether to an inlet, manhole, or direct connection must be approved by the City of Altoona. A separate fee will be charged by the City of Altoona for the tapping of any public storm sewer or existing inlet. Said fee shall include the cost of the tap inspection.

Prohibitions.

(1)

Prohibited discharges. Any drain or conveyance whether on the surface or subsurface, that allows any nonstormwater discharge including sewage, process wastewater, and wash water to enter a regulated MS4 or to enter the waters of the commonwealth is prohibited.

(a)

No person in the City shall allow, or cause to allow, discharges into the separate storm sewer system (MS4) or discharges into any waters of the commonwealth, which are not composed entirely of stormwater, except discharges allowed under a state or federal permit.

(b)

Discharges which may be allowed, based on a DEP determination or a finding by the Stormwater Officer that the discharges do not significantly contribute pollution to a regulated MS4 or surface waters of the commonwealth of Pennsylvania, are:

[1]

Discharges from fire-fighting activities.

[2]

Potable water sources including dechlorinated waterline and fire hydrant flushing.

[3]

Irrigation drainage.

[4]

Routine external building wash down (which does not use detergents or other compounds).

[5]

Air-conditioning condensate.

[6]

Water from individual residential car washing.

[7]

Water from crawl space (sump) pumps.

[8]

Uncontaminated water from foundation and/or footing drains.

[9]

Flows from riparian habitats and wetlands.

[10]

Lawn watering.

[11]

Pavement wash waters where spills or leaks of toxic or hazardous materials have not occurred (unless all spill material has been removed) and where detergents are not used.

[12]

Dechlorinated swimming pool discharges.

[13]

Uncontaminated groundwater.

[14]

Springs and diverted stream flows.

(c)

In the event that the Stormwater Officer or DEP determines that any of the discharges identified in Subsection E(1)(b) significantly contribute pollution to a regulated MS4 or to waters of the commonwealth, the Stormwater Officer or DEP will notify the responsible person(s) to cease the discharge.

(d)

Upon notice provided by the Stormwater Officer under Subsection E(1)(c), the person(s) causing the discharge will be given a time, as determined by the Stormwater Officer, to cease the discharge consistent with the degree of pollution caused by the discharge.

(e)

Nothing in this section shall affect a discharger's responsibilities under state or federal law.

(2)

Prohibited connections.

(a)

Except as provided in Subsection D(1) above, any drain or nonstormwater conveyance, whether on the surface or subsurface, which allows any nonstormwater discharge including sewage, process wastewater, and wash water to enter the separate storm sewer system is prohibited. In addition any connections to the storm sewer system from indoor drains and sinks are prohibited.

(b)

Except as provided in Subsection D(1) above, any drain or conveyance connected from a commercial or industrial land use to the separate storm sewer system which has not been documented in plans, maps, or equivalent records and approved by the City is prohibited.

(3)

Roof drains.

(a)

Roof drains shall not be connected to streets, sanitary or storm sewers or roadside ditches except as provided in Subsection D(3)(b) below.

(b)

When it is more advantageous to connect directly to streets or storm sewers, connections of roof drains to streets or roadside ditches may be permitted by the Stormwater Officer.

(c)

Roof drains and sump pumps shall discharge to infiltration areas or vegetative BMPs to the maximum extent practicable.

(4)

Alteration of BMPs.

(a)

No person shall modify, remove, fill, landscape or alter any existing stormwater BMP, unless it is part of an approved maintenance program without the written approval of the City Engineer or Stormwater Officer.

(b)

No person shall place any structure, fill, landscaping or vegetation into a stormwater BMP or within a drainage easement which would limit or alter the functioning of the BMP without written approval of the Stormwater Officer.

§ 620-13 Stormwater plan requirements.

General requirements. No permit authorizing construction can be issued, nor can any clearing and grubbing, or earth moving or land disturbance activity be initiated until the final stormwater management plan for the development site is approved and a stormwater consistency letter issued in accordance with the provisions of this article. Stormwater management plans shall be approved as part of the required land development reviews in a sequence and manner best fitting the site and situation of the project.

Exemptions. The following activities are exempt from the stormwater management plan preparation provisions of this article. Exemption shall not relieve the applicant from providing adequate stormwater management to meet the purpose of this article.

(1)

Any regulated activity that would create 5,000 square feet or less of impervious area. This criterion shall apply to the total development even if development is to take place in phases. For the purpose of stormwater management there will be no development phasing. Even if no plan is required, the owner still must provide adequate stormwater management, such as roof drain seepage pits or any other stormwater management that may be required by the City.

(a)

As stated, exemption shall not relieve the applicant from providing adequate stormwater management to meet the purpose of this article; in particular, § 620-12A(1) and (2).

(b)

Exemption based on impervious area must be verified through a stormwater narrative which includes a plan or sketch documenting all pervious and impervious areas with dimensions and area calculations shown for both existing and proposed conditions.

(c)

Credit for impervious areas from buildings, paved areas, sidewalks, etc., which have been removed or razed can only be credited within 12 months from the date of removal or razing. After the twelve-month time frame, the existing site condition shall apply.

(2)

Land disturbance associated with existing one- and two-family dwellings.

(3)

Use of land for gardening for home consumption.

(4)

Agriculture when operated in accordance with a conservation plan or erosion and sedimentation control plan approved by the Conservation District. The agricultural activities, such as growing crops, rotating crops, filling of soil and grazing animals and other such activities, are specifically exempt from complying with the requirements of this article when such activities are conducted in accordance with a conservation plan prepared by the Blair County Conservation District. The construction of buildings, parking lots or any activity that may result in impervious surface which increases the rate and volume of stormwater runoff shall comply with the requirements of this article.

(5)

Forest management operations which are following the Department of Environmental Protection's management practices contained in its publication Soil Erosion and Sedimentation Control Guidelines for Forestry and are operating under an erosion and sedimentation control plan.

Stormwater plan contents. Stormwater plan contents shall conform to the requirements of the appropriate sections of the City's Subdivision and Land Development Ordinance,[1] this chapter, as well as but not limited to, the following:

(1)

The City shall not approve any SWM plan that is deficient in meeting the requirements of this chapter. At its sole discretion and in accordance with this chapter when a SWM plan is found to be deficient, the City may either disapprove the submission and require a resubmission, or in the case of minor deficiencies, the City may accept corrections or submission of modifications.

(2)

Provisions for permanent access or maintenance easements for all physical Stormwater Management BMPs, such as ponds and infiltration structures, as necessary to implement the Operation and Maintenance as discussed in § 620-8.

(3)

A statement, signed by the landowner, acknowledging that the stormwater BMPs are fixtures that cannot be altered or removed without written approval by the City Engineer.

(4)

A signature block on the plans that reads: "I (qualified professional), on this date (date of signature), hereby certifies that the stormwater management site plan meets all design standards and criteria of Chapter 620 of the City of Altoona codified ordinances, as amended (number assigned to the ordinance)."

(5)

Existing and proposed features. The plan shall provide the overall stormwater management concept for the project as well as show the following under both predevelopment and postdevelopment conditions:

(a)

A determination of site conditions in accordance with this chapter, NRCS TR55, and the PA BMP Manual.

(b)

The design professional shall perform a detailed site evaluation for projects proposed in areas of carbonate geology or karst topography, and other environmentally sensitive areas, such as brown fields.

(c)

Stormwater runoff design computations and documentation as specified in this chapter, or as otherwise necessary to demonstrate that the maximum practicable measures have been taken to meet the requirements of this chapter.

(d)

Floodplain boundaries. Identify one-hundred-year floodplains on the development site (as appropriate) based on the FEMA Flood Study maps.

(e)

Natural features. Show all bodies of water (natural or artificial), watercourses (permanent and intermittent) swales, wetlands and other natural drainage courses on the development site, or which will be affected by runoff from the development.

(f)

Soils. Provide an overlay showing soil types and boundaries within the development site with identification of the Hydraulic Soil Group classification (consult the Conservation District, SCS and United States Geological Survey for information).

(g)

Contours. Show existing and final contours at intervals of two feet; in areas with slopes greater than 15%, five-foot contour intervals may be used.

(h)

Land cover. Show existing and final land cover classifications as necessary to support and illustrate the runoff calculations performed.

(i)

Drainage area delineations. Show the boundaries of the drainage areas employed in the runoff calculations performed.

(j)

Stormwater management control. Show any existing stormwater management or drainage controls and/or structures, such as storm sewers, swales, culverts, etc, which are located on the development site, or which are located off-site but will be affected by runoff from the development.

(k)

A soil erosion and sediment control plan, where applicable, as prepared for and submitted to the Blair County Conservation District. An approved (by the Blair County Conservation District) E&S plan must be provided to the City.

(l)

The effect of the project (in terms of runoff volumes, water quality, and peak flows) on surrounding properties and aquatic features and on any existing stormwater conveyance system that may be affected by the project.

(m)

Plan and profile drawings and construction details of all stormwater management BMPs, including drainage structures, pipes, open channels, and swales.

(n)

The stormwater management site plan shall show the locations of existing stormwater management facilities as well as existing or proposed on-lot wastewater facilities and water supply wells.

(o)

The stormwater management site plan shall include an operation and maintenance plan for all existing and proposed physical stormwater management facilities. This plan shall address long-term ownership and responsibilities for operation and maintenance (O&M) as well as schedules for O&M activities.

(p)

Easements, rights-of-way, deed restrictions. All existing and proposed easements and rights-of-way for drainage and/or access to stormwater control facilities shall be shown along with any areas subject to special deed restrictions relative to or affecting stormwater management on the development site.

[1]

Editor's Note: See Ch. 640, Subdivision of Land and Land Developments.

Stormwater Plan review. Plans shall be reviewed for consistency in accordance with the provisions of this chapter. The City shall not approve any stormwater management plan that is deficient in meeting the requirements of this chapter. At its sole discretion and in accordance with this article, when a stormwater management plan is found to be deficient, the City may either disapprove the submission and require a resubmission, or in the case of minor deficiencies, the municipality may accept submission of modifications or corrections.

Stormwater report requirements. The stormwater management site report shall include, but not be limited to, the following information:

(1)

The name of the development; name and location address of the property site; name, address, and telephone number of the applicant/owner of the property; and name, address, telephone number, email address, and engineering seal and signature of the individual preparing the stormwater management site report.

(2)

Adhere to all the provisions of § 620 for stormwater management technical standards with regard to stormwater rate of runoff, volume, and quality, and calculation methods.

(3)

Project description narrative including expected project time schedule.

(4)

Location map showing the project site.

(5)

Drainage area maps for all watersheds and inlets depicting the time of concentration paths.

(6)

A detailed description of the existing site conditions and area calculations, in square feet for areas under an acre and acres for areas over an acre, for each condition.

(7)

Provide complete hydrologic, hydraulic, structural computations, calculations, hydrographs, assumptions, and all other criteria for design of all stormwater BMPs.

(8)

Description of, justification, and actual field results for infiltration testing with respect to type of test and test location for the design of infiltration BMPs.

(9)

Calculations showing the total drainage area and impervious area loading rates to each BMP.

(10)

The effect of the project (in terms of runoff volumes, water quality, and peak flows) on all properties and aquatic features and on any existing municipal stormwater collection system that may receive runoff from the project site.

(11)

Description of any proposed changes to the land surface and vegetative cover, including the type and amount of impervious area to be added.

(12)

All applicable worksheets from Chapter 8 of the BMP Manual when establishing volume controls and water quality compliance.

(13)

Identification of short-term and long-term ownership, operation, and maintenance responsibilities as well as schedules and costs for inspection and maintenance activities for each permanent stormwater or drainage BMP, including provisions for permanent access or maintenance easements.

As-built plans.

(1)

The developer or their engineer shall be responsible for providing as-built plans of all stormwater management (SWM) BMPs included in the approved SWM site plan. The as-built plans and an explanation of any discrepancies with the construction plans shall be submitted to the City. Include a final certification statement to the as-built or record drawings which reads: "I (name) do hereby certify pursuant to the penalties of 18 Pa.C.S.A. § 4904 to the best of my knowledge, information, and belief, that the accompanying record drawings accurately reflect the as-built conditions, are true and correct, and are in conformance with the City's ordinance and the rules and regulations of the Department of Environmental Protection and that the project site was constructed in accordance with the approved PCSM Plan, all approved plan changes and accepted construction practices."

(2)

Licensed professional oversight of critical stages. A licensed professional or a designee shall be present onsite and be responsible during all critical stages of implementation of the approved post construction stormwater maintenance plan. The critical stages will include critical processes of the installation of underground treatment or storage BMPs, structurally engineered BMPs, and all other BMPs unless deemed inappropriate or unnecessary by the City of Altoona or the Department of Environmental Protection.

§ 620-14 Authorization to construct and terms of validity.

The City's approval of an SWM site plan authorizes the regulated activities contained in the SWM site plan for a maximum term of validity of five years following the date of approval. The City may specify a term of validity shorter than five years in the approval for any specific SWM site plan. Terms of validity shall commence on the date the municipality signs the approval for an SWM site plan. If an approved SWM site plan is not completed according to the term of validity, then the municipality may consider the SWM site plan disapproved and may revoke any and all permits or approvals. SWM site plans that are considered disapproved by the municipality shall be resubmitted in accordance with the appropriate sections of this chapter.

§ 620-15 Operation and maintenance.

Operation and maintenance responsibilities.

(1)

Facilities, areas, or structures used as stormwater management BMPs shall be enumerated as permanent real estate appurtenances and recorded as deed restrictions or conservation easements that run with the land.

(2)

Approved operation and maintenance (O&M) plans for stormwater management shall be recorded as a restrictive deed covenant that runs with the land.

(3)

The City may take enforcement actions against an owner for any failure to satisfy the provisions of this chapter.

(4)

The stormwater management plan for the development site shall contain an operation and maintenance plan prepared by the developer or developer's engineer and approved by the Planning Agency on the recommendations of the Stormwater Officer. The operation and maintenance plan shall outline required routine maintenance actions and schedules necessary to ensure proper operation of the facility(ies).

(5)

A note on the plan indicating the location and responsibility for maintenance of stormwater management facilities that would be located off site. All off site facilities shall meet the performance standards and design criteria specified in this article.

(6)

A statement, signed by the landowner, acknowledging the stormwater management system to be a permanent fixture that can be altered or removed only after approval by the City of a revised plan, shall be placed on the title sheet of the plans.

(7)

The maintenance plan for stormwater management facilities located on the development site shall establish responsibilities for the continuing operation and maintenance of all proposed stormwater control methods and facilities, consistent with the following principles:

(a)

If a development consists of structures or lots which are to be separately owned and in which streets, storm sewers, and other public improvements located in the right-of-way are to be dedicated to the City of Altoona, stormwater control facilities located within these public improvements shall also be dedicated to and maintained by the City of Altoona.

(b)

If a development site is to be maintained in a single ownership or if storm sewers and other public improvements are to be privately owned and maintained, then the ownership and maintenance of stormwater control methods and facilities shall be the responsibility of the owner or private management entity.

(c)

Any existing inlets, piping, ditches, swales, channels, etc. located within a site and/or property are considered stormwater facilities. These existing facilities are considered private, and maintenance of the stormwater management facilities will be required and the responsibility of the owner or private management entity.

(8)

The City or the Stormwater Officer shall make the final determination regarding the continuing maintenance responsibilities prior to final approval of the stormwater management plan. Notwithstanding any provision to the contrary herein, City Council reserves the right to accept or reject the ownership and operating responsibility for any or all of the stormwater control methods and facilities, and to determine the terms and conditions under which it will accept ownership and operating responsibility.

(9)

Requirements and agreement for the operation and maintenance plan as submitted and approved will be covered under the Developers Agreement between the City and the developer. If for whatever reason a developer's agreement is not required a separate operation and maintenance agreement will be required.

Maintenance agreement for privately owned stormwater facilities.

(1)

The City or its Stormwater Officer shall make final determination on the continuing maintenance responsibilities prior to final approval of the SWM plan. Upon final approval of the site's stormwater management plan, the property owner and the City shall execute (sign and record) a developers agreement covering all stormwater control facilities which are to be privately owned. The developers agreement shall be recorded with the final subdivision/land development plan for the site. The agreement shall stipulate that:

(a)

The owner, successor and assigns shall operate and maintain all facilities in accordance with the approved maintenance schedule(s) in the O&M plan and shall keep all facilities in a safe and attractive manner.

(b)

The owner shall convey to the City of Altoona easements and/or rights-of-way to assure access for periodic inspections by the City of Altoona and maintenance, if necessary or required.

(c)

The owner shall keep on file with the City of Altoona the name, address and telephone number of the person or company responsible for operation and maintenance activities. In the event of a change, new information will be submitted by the owner to the City of Altoona within 10 working days of the change.

(d)

The engineer must meet with and provide the developer or owner with a copy of the operation and maintenance plan. The engineer is required to explain all required maintenance to the developer or owner as well as all associated requirements of this chapter (i.e., recordkeeping, contact information, submittal of records, etc.)

(e)

The owner is responsible for operation and maintenance (O&M) of the SWM BMPs. If the City of Altoona determines at any time that any permanent stormwater management control facility has been eliminated, altered or improperly maintained in accordance with the O&M agreement, the owner of the property shall be advised of corrective measures required and given a reasonable period of time to take necessary action. If such action is not taken by the property owner, the City of Altoona may institute penalties or cause the work to be done, file a municipal claim or lien against the property, or institute an action in assumpsit against the property owner, to collect all costs, i.e., contractor's work, administrative costs, filing, fees, and interest at 6% on the unpaid balance.

(2)

Other items may be included in the agreement where determined necessary to guarantee the satisfactory maintenance of all facilities. The maintenance agreement shall be subject to the review and approval of the Municipal Solicitor and governing body.

(3)

Municipal stormwater maintenance fund.

(a)

Persons installing stormwater storage facilities shall be required to pay a specified amount to the municipal stormwater maintenance fund to help defray costs of periodic inspections and maintenance expenses. The amount of the deposit shall be determined as follows:

[1]

If the storage facility is to be privately owned and maintained, the deposit shall cover the cost of periodic inspections performed by the City of Altoona for a period of 10 years, as established by the City fee schedule or as estimated by the Stormwater Officer. After that period of time, inspections will be performed at the expense of the City. Said fee may also be used to help defray the costs of maintaining the existing separate storm system within the City of Altoona.

[2]

If the storage facility is to be owned and maintained by the City of Altoona, the deposit shall cover the estimated costs for maintenance and inspections for 10 years. The Stormwater Officer will establish the estimated costs utilizing information submitted by the applicant.

[3]

The amount of the deposit to the fund shall be converted to present worth of the annual series values. The Stormwater Officer shall determine the present worth equivalents, which shall be subject to the approval of the planning agency.

(b)

If a storage facility is proposed that also serves as a recreation facility (e.g., ball field, park, lake, etc.), the Altoona City Planning Commission may reduce or waive the amount of the maintenance fund deposit based upon the value of the land for public recreation purposes.

(c)

If in the future a storage facility (whether publicly or privately owned) is eliminated due to the installation of storm sewers or other storage facility, the unused portion of the maintenance fund deposit will be applied to the cost of abandoning the facility and connecting to the storm sewer system or other facility. Any amount of the deposit remaining after the costs of abandonment are paid will be returned to the depositor.

(d)

In the event of a dispute between the owner and the Stormwater Officer over the amount of the maintenance fund deposit, both parties shall appear before the Planning Commission, which shall mediate the dispute. Parties aggrieved by the Commission's decision may appeal to a court of competent jurisdiction.

Postconstruction inspections of stormwater facilities.

(1)

The owner of the stormwater management facilities shall a keep record or log of all activities undertaken in compliance with the approved maintenance schedule, as well as any other maintenance activities that were necessary.

(2)

Said records shall be kept on site, accessible and opened to the Stormwater Officer upon request so that he or she may verify that maintenance is proceeding as approved. A copy of the prior year's maintenance records will be submitted to the City of Altoona Public Works Department, no later than January 31 of each year. Send to the attention of: Stormwater Officer, City Hall, Suite 300, 1301 12th Street, Altoona, PA, 16601.

(3)

The stormwater management facilities shall be made available to the Stormwater Officer upon request for the purpose of inspection.

(4)

Where the stormwater management facilities are tied into a combined sewer system, the Altoona City Authority shall also have the same inspection rights as the Stormwater Officer so as to properly operate the sewer system. This includes the imposition of permits and fees as deemed necessary by said Authority.

(5)

Stormwater management facilities shall be inspected by the Stormwater Officer at a minimum of once in every two-year period.

§ 620-16 Fees and expenses.

Review fees.

(1)

The City may include all costs incurred in the review fee charged to the applicant. In-house costs will be hourly rate plus benefits, rounded to the nearest 1/2 hour. The review fee may include, but not be limited to, costs for the following.

(a)

Review of the SWM site plan, details, and any other STM related plans.

(b)

Review of the SWM narrative including all calculations, hydrographs, etc.

(c)

All administrative/clerical processing.

(d)

Attendance at meetings.

(e)

Any independent reviews, may be in addition or in lieu of in-house reviews.

(2)

Average cost calculated and included in the City's fee schedule as established by resolution of City Council from time to time. (Any independent reviews would be additional and at reimbursement cost.)

Construction inspection. The City may include all costs incurred in the reimbursement of construction inspection costs for the SWM facilities (BMPs) inspection. The reimbursement costs may include, but not be limited to, costs for the following:

(1)

All time involved in the inspection including travel time (hourly pay plus benefits), rounded to the nearest 1/2 hour.

(2)

Travel time and mileage.

(3)

All administrative/clerical processing.

Postconstruction maintenance inspection fee.

(1)

The postconstruction inspection fee will be for the annual or semiannual maintenance inspection. The fee will be as calculated for the maintenance inspection, including but not be limited to the following costs:

(a)

All time involved in the inspection including BMP maintenance inspection, record review, and travel time (hourly pay plus benefits) rounded to the nearest 1/2 hour.

(b)

Office plan review and correspondence.

(c)

All administrative/clerical processing.

(d)

Follow up, if required.

(2)

The average cost for 10 years of postconstruction inspections for small, regular, and large stormwater management facilities has been calculated and included in the City's fee schedule adopted by resolution of City Council from time to time.

§ 620-17 Enforcement and penalties.

Right-of-entry.

(1)

The Stormwater Officer or any duly authorized representatives of the City may enter at reasonable times upon any property within the City to investigate, inspect, or ascertain the condition of the stormwater structures and facilities of the subject property in regard to any aspect regulated by this chapter.

Inspection.

(1)

SWM BMPs should be inspected by the landowner, or the owner's designee according to the individual maintenance agreement for the property or SWM BMPs.

(2)

If a maintenance time frame is not specifically referred to, the BMPs, at a minimum will be inspected by the owner annually, and after every ten-year or greater storm.

Enforcement.

(1)

The City of Altoona is hereby authorized and directed to enforce all of the provisions of this chapter.

(a)

A set of design plans approved by the City shall be on file at the site throughout the duration of the construction activity. Periodic inspections may be made at anytime by the City during construction.

(b)

It shall be unlawful for any person, firm, or corporation to undertake any regulated activity on any property except as provided for in the approved drainage or stormwater management plan and pursuant to this chapter. It shall be unlawful to alter or remove any control structure required by the stormwater management plan pursuant to this chapter or to allow the property to remain in a condition which does not conform to the approved stormwater plans.

(c)

At the completion of the project and prior to occupying of the site, the owner or said owner's representative shall provide to the City of Altoona:

[1]

A certification of completion from an engineer or other qualified person verifying that all permanent facilities have been constructed according to the plans and specifications and approved revisions thereto.

[2]

A set of as-built drawings.

(d)

Occupancy permit. An occupancy permit shall not be issued unless the certification of completion and record drawings have been secured and all fees due and owing to the City have been paid in full.

(e)

Prior to revocation or suspension of a permit, the City will schedule a meeting to discuss the noncompliance if there is no immediate damage to life, public health or property.

Suspension and revocation.

(1)

Any approval or permit issued may be suspended or revoked by the City for:

(a)

Noncompliance with or failure to implement any provision of the stormwater plan or the O&M agreement.

(b)

A violation of any provision of this chapter or any other applicable law, ordinance, rule, or regulation relating to the project or stormwater activity.

(c)

The creation of any condition or the commission of any act during construction or development which constitutes or creates a hazard, nuisance, pollution, or which endangers the life or property of others.

(2)

A suspended approval or permit shall be reinstated by the City of Altoona when:

(a)

The City, or its designee has inspected and approved the corrections to the stormwater management measures, or the elimination of the hazard or nuisance,

(b)

The City is satisfied that the violation of the ordinance, law, or rule and regulation has been corrected.

(3)

An approval or permit which has been revoked by the City cannot be reinstated. The applicant may apply for approval or a new permit under the provisions of this chapter.

Notification.

(1)

In the event that an owner, developer or their agent, or any person fails to comply with the requirements of this chapter, provided it does not cause any immediate danger to life, health, or property or fails to conform to the requirements of any permit issued hereunder, the City shall provide written notification of the violation. Such notification shall set forth the nature of the violation(s) and establish a time limit for correction of these violation(s). Failure to comply within the time specified shall subject such person to the penalty provisions of this chapter. All such penalties shall be deemed cumulative and shall not prevent the City from pursuing any and all remedies. It shall be the responsibility of the owner of the real property on which any regulated activity is proposed to occur, is occurring, or has occurred, to comply with the terms and conditions of this chapter.

(2)

As a result of an on-site inspection by the Stormwater Officer or designee of City of Altoona, if it has been determined that an owner, developer, or their agent has failed to comply with the terms and conditions of this chapter, or fails to conform to the requirements of any permit or agreement issued thereunder, the City or its designee shall provide written notification of violation within 10 days of said on-site inspection. The violation shall be deemed a public nuisance, and the notification shall set forth the nature of the violation(s) and establish a time limit for correction of these violation(s). Upon failure to comply within the time specified, the owner, developer, or their agent shall be subject to the penalty provisions of this chapter or other penalty.

(3)

Each day that the public nuisance violation continues shall be a separate offense. In addition, the City may institute injunctive mandamus or any other appropriate action or proceeding at law or in equity for the enforcement of this chapter. Any court of competent jurisdiction shall have the right to issue restraining orders, temporary or permanent injunctions, mandamus, or other appropriate forms of remedy or relief.

Enforcement remedies and penalties.

(1)

Any person, firm, or corporation who shall violate any provision of this chapter, upon conviction thereof in an action brought before a magisterial district judge in the manner provided for the enforcement of summary offenses under the Pennsylvania Rules of Criminal Procedure, shall be sentenced to pay a fine of not more than $1,000 plus costs and, in default of payment of said fine and costs, to a term of imprisonment not to exceed 30 days. Each day that a violation of this part continues or each section of this chapter which shall be found to have been violated shall constitute a separate offense.

(2)

In addition, the City, through its Solicitor may institute injunctive, mandamus or any other appropriate action or proceeding at law or in equality for the enforcement of this chapter. Any court of competent jurisdiction shall have the right to issue restraining orders, temporary or permanent injunctions, mandamus or other appropriate forms of remedy or relief.

§ 620-18 Appeals.

Appeal to Appeals Board.

(1)

Any person aggrieved by any action of the City or its agent, relevant to the provisions of this chapter, may appeal to the Board of Appeals established pursuant to Chapter 15, Article VIII, § 15-31 et seq. of this Code within 30 days of that action. Said Board of Appeals is hereby given the authority to entertain such appeals and may interpret the provisions of this chapter as necessary to decide such an appeal.

Appeal to court.

(1)

Any person aggrieved by any decision of the City Appeals Board, relevant to the provisions of this chapter, may appeal to the County Court of Common Pleas in Blair County where the activity has taken place as provided in Chapter 15 for appeals from the Appeal Board.