For the purposes of these regulations, the following definitions describe the meaning of the terms used in these regulations and in the Sumner Development Specifications and Standard Details:
1. "Adverse impact"
means any deleterious effect on waters or wetlands, including their quality, quantity, surface area, species composition, aesthetics or usefulness for human or natural uses which are or may potentially be harmful or injurious to human health, welfare, safety or property, to biological productivity, diversity, or stability or which unreasonably interfere with the enjoyment of life or property, including outdoor recreation.
2. "Agricultural land management practices"
means those methods and procedures used in the cultivation of land in order to further crop production and conservation of related soil and water resources.
3. "Applicant"
means any person, firm, or government agency who executes the necessary forms to procure official approval of a project or a permit to carry out construction of a project.
4. "Aquifer"
means a porous, water-bearing geologic formation generally restricted to materials capable of yielding an appreciable supply of water.
5. "Artificial slope"
means a human-made construction of inclined earth which is designed to perform a specific function in a project or graded area not including existing slopes or manmade slopes altered through natural processes such as erosion.
6. "Best management practice (BMP)"
means the schedules of activities, prohibitions of practices, maintenance procedures, and structural and/or managerial practices that, when used singly or in combination, prevent or reduce the release of pollutants and other adverse impacts to waters of Washington State.
7. "Bond"
means a surety bond or assignment of funds to guarantee all work is done in compliance with all applicable city requirements.
8. "Buffer area"
is defined in the city of Sumner shoreline master program as currently adopted. Buffers shall not be used for stormwater management facilities unless otherwise specifically allowed in SMC Title 16.
9. "City"
means the city of Sumner, Washington, or, as indicated by the context, may mean the public works department, public works director, public works superintendent, city engineer, or other employee or agent representing the city in the discharge of his or her duties.
10. "City council"
means the publicly elected body of local representatives for the incorporated city of Sumner, Washington, vested with the power to enact and repeal local laws, regulations, rules, policies, and procedures.
11. "City engineer"
means the directing engineer for the city. Any act in this chapter requiring the authorization of the city engineer may be done by an authorized employee of the engineering department.
12. "Civil engineer"
means a professional engineer registered in the state of Washington to practice in the field of civil engineering.
13. "Clearing"
means the removal of trees, brush, and other vegetative growth from the land in such a manner to affect the erosion potential of the soils on a site. "Clearing" shall not include the ordinary mowing of grass.
14. "Construction"
means the implementation of all land-disturbing activities.
15. "Construction stormwater pollution prevention plan"
means an engineering plan showing all BMPs, controls, and measures which will be implemented by the applicant to minimize erosion on the subject property and remove suspended sediment from site runoff during and immediately after the period of construction or other land-disturbing activity. The construction stormwater pollution prevention plan is a required element of a stormwater site plan and shall be developed in accordance with the manual.
16. "Continuous construction"
means an orderly sequential construction with no significant delays due to factors within the control of the applicant.
17. "Detention facilities"
means facilities designed to hold runoff for a period of time and then release it to a natural or manmade watercourse at a predetermined rate generally approximating what would have occurred under predevelopment conditions.
18. "Development"
means land-altering activities that change the runoff characteristics of a parcel of land in conjunction with residential, commercial, industrial, or institutional construction or alteration. "Development" includes construction of new structures or redevelopment of previously altered sites.
New development includes land-disturbing activities, including Class IV – General forest practices that are conversions from timberland to other uses; structural development, including construction or installation of a building or other structure; creation of impervious surfaces; and subdivision, short subdivision and binding site plans, as defined and applied in chapter 58.17 RCW. Projects meeting the definition of "redevelopment" shall not be considered new development. |
On a site that is already substantially developed (that has 35 percent or more of existing impervious surface coverage), "redevelopment" means the creation or addition of impervious surfaces; the expansion of a building footprint or addition or replacement of a structure; structural development including construction, installation or expansion of a building or other structure; replacement of impervious surface that is not part of a routine maintenance activity; and land-disturbing activities. |
19. "Sumner Development Specifications and Standard Details"
means the specifications and standard details manual available from the public works department that contains technical specifications and details for the design, construction, and maintenance of stormwater facilities.
20. "Drainage"
means water originating from rainfall or other precipitation which is transmitted downhill through sheet flow, rivulets, channels, drainage ditches, pipes, creeks, streams, and rivers.
21. "Drainage area"
means that area contributing runoff to a single point measured in a horizontal plane, which is enclosed by a ridge line.
22. "Drainage basin plan"
means the plan adopted by ordinance for managing storm drainage and surface water runoff facilities and features within the city's drainage basins.
23. "Easement"
means a grant or reservation by the owner of land for the use of such land by others for a specific purpose or purposes, and which must be included in the conveyance of land affected by such easement.
25. "Equivalent service unit (ESU)"
means and is equal to 3,100 square feet of impervious groundcover to be used by the city in assessing service fees for the storm drainage utility and determining system development charges. A single-family residential parcel is designated as a single ESU irrespective of the size of parcel or the amount of impervious area on such parcel, until such time as the parcel is segregated or the use of the land is modified to other than single-family.
26. "Erosion"
means the wearing away of land surface from action of wind, water, gravity or any combination thereof.
27. "Erosion and sediment control best management practices (BMPs)"
means a practice, control device, or construction method which is designed to either prevent erosion or remove suspended sediment from runoff. Erosion and sedimentation control BMP options are identified in Volume II of the manual.
28. "Exemption"
means those land development activities that are not required to develop a stormwater site plan as outlined in these regulations.
29. "Existing conditions"a. b. i. ii. c. i. ii. iii. iv.
means:
Existing site conditions for sites that have not been developed or altered since 1993;
Existing site conditions for sites that have been developed or altered after 1993 if:
A building or grading permit was issued and includes a drainage system that was designed and constructed in accordance with the requirements of this chapter in effect at the time the permit was issued; or
A building or grading permit was issued but received an exemption or waiver from the city from compliance with this chapter in effect at the time the permit was issued;
Vegetated pervious cover for sites developed or altered after 1993 if:
A building or grading permit was required but application to the city was not provided; or
A drainage system was not designed and constructed in accordance with the requirements of this chapter in effect at the time of construction; or
Did not receive an exemption or waiver from the city for compliance with this chapter in effect at the time of construction;
Vegetated pervious cover shall be considered 100 percent pasture unless the site or portions thereof were wooded or forested prior to site work.
30. "Fee and rate schedule"
means the list of charges, to applicants or other persons, established by the city council to reimburse the city for time spent in review of permit applications and inspection of potential or actual violations of law.
31. "Flow attenuation"
means detaining or retaining runoff to reduce the peak discharge.
32. "Grading"
means any act by which soil is cleared, stripped, stockpiled, excavated, scarified, filled or any combination thereof. "Grading" also means movement of earth requiring the removal of most or all of the existing vegetation and in sufficient quantities to alter the natural topography and general character of a site.
32.5. "Hard surfaces"
means an impervious surface, a permeable pavement, or a vegetated roof.
33. "Illicit connection"
means any manmade conveyance that is connected to a municipal separate storm sewer without a permit, excluding roof drains and other similar type connections. Examples include sanitary sewer connections, floor drains, channels, pipelines, conduits, inlets, or outlets that are connected directly to the municipal separate storm sewer system.
34. "Illicit discharge"
means any discharge to a municipal separate storm sewer that is not composed entirely of stormwater except discharges pursuant to a NPDES permit (other than the NPDES permit for discharges from the municipal separate storm sewer) and discharges resulting from fire-fighting activities. Illicit discharges include, but are not limited to, sanitary sewer connections, industrial process water, interior floor drains, fuel islands, car washing, and grey water systems. Illicit discharges are further described in SMC § 13.48.820. Discharges from fire-fighting activities are not included in the definition of "illicit discharges."
35. "Impervious surface"
is a nonvegetated surface area that either prevents or retards the entry of water into the soil mantle under natural conditions prior to development, or which causes water to run off the surface in greater quantities or an increased rate of flow from the flow present under natural conditions prior to development. "Surfaces" include, but are not limited to, roof tops, walkways, patios, driveways, parking lots or storage areas, asphalt or concrete paving, gravel roads, packed earthen materials, and oiled, macadam, or other surfaces which similarly impede the natural infiltration of stormwater.
Open, uncovered retention/detention facilities shall not be considered as impervious surface for the purposes of determining whether thresholds for application of minimum requirements are exceeded. Open, uncovered retention/detention facilities shall be considered impervious surface, however, for the purposes of hydrologic modeling. |
For stormwater design, flow control, and water quality treatment purposes, graveled or rock surfaces for parking lots, storage areas, driveways, and other uses approved and constructed in accordance with city standards are considered impervious areas. |
For calculating rates and fees for the stormwater utility, graveled or rock surfaces for parking lots, storage areas, driveways, and other uses, whether existing or approved and constructed in accordance with city standards and requirements, and water surface areas of stormwater facilities, are not considered impervious areas. |
36. "Infiltration"
means the downward movement of water from the surface to the subsoil.
37. "Land-disturbing activities"
means any activity that results in a change in the existing soil cover (both vegetative and nonvegetative) and/or the existing soil topography. "Land-disturbing activities" include, but are not limited to, clearing, grading, filling, and excavation. Compaction that is associated with stabilization of structures and road construction shall also be considered a land-disturbing activity. Vegetation maintenance practices, including landscaping maintenance and gardening, are not considered land-disturbing activity. Stormwater facility maintenance is not considered land-disturbing activity if conducted according to established standards and procedures.
38. "Low impact development"
means a stormwater and land use management strategy that strives to mimic pre-disturbance hydrologic processes of infiltration, filtration, storage, evaporation and transpiration by emphasizing conservation, use of on-site natural features, site planning, and distributed stormwater management practices that are integrated into a project design.
40. "Minimum requirements"a. b. c. d. e. f. g. h. i.
means the minimum requirements for stormwater management described in the NPDES Phase II permit. The minimum requirements include:
Minimum Requirement 1, Preparation of Stormwater Site Plans.
Minimum Requirement 2, Construction Stormwater Pollution Prevention Plan (SWPPP).
Minimum Requirement 3, Source Control of Pollution.
Minimum Requirement 4, Preservation of Natural Drainage Systems and Outfalls.
Minimum Requirement 5, On-Site Stormwater Management.
Minimum Requirement 6, Runoff Treatment.
Minimum Requirement 7, Flow Control.
Minimum Requirement 8, Wetlands Protection.
Minimum Requirement 9, Operation and Maintenance.
41. "Municipal separate storm sewer system (MS4)"a. b. c. d.
means a conveyance, or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, manmade channels, or storm drains):
Owned or operated by a state, city, town, borough, county, parish, district, association, or other public body (created by or pursuant to state law) having jurisdiction over disposal of industrial wastes, stormwater, or other wastes, including special districts under state law such as a sewer district, flood control district, or drainage district, or similar entity, or an Indian tribe or an authorized Indian tribal organization, or a designated and approved management agency under the federal Clean Water Act (CWA) Section 208 that discharges to waters of the United States;
Designed or used for collecting or conveying stormwater;
Which is not a combined sewer; and
Which is not part of a publicly owned treatment works (POTW) as defined in 40 CFR 122.2.
42. "National Pollutant Discharge Elimination System (NPDES)"
means the national program for issuing, modifying, revoking, and reissuing, terminating, monitoring, and enforcing permits, and imposing and enforcing pretreatment requirements, under Sections 307, 318, 402, and 405 of the CWA, for the discharge of pollutants to surface waters of the state from point sources. These permits are referred to as NPDES permits and, in Washington State, are administered by the Washington Department of Ecology.
43. "Notice of violation"
means the written document served on an applicant or other person subject to the provisions of this chapter which precedes all forms of enforcement actions including stop work orders, revocation of permits, and assessment of cumulative civil penalties.
44. "NRCS"
means the Natural Resource Conservation Service, formerly the Soil Conservation Service. The NRCS is a federal agency within the United States Department of Agriculture.
45. "NPDES Phase II permit"
means the stormwater permit issued by Ecology in accordance with the NPDES as promulgated under the CWA.
46. "On-site stormwater management"
means the design and construction of systems necessary to control stormwater within an immediate development.
47. "Permittee"
means the person, property owner, corporation, utility, government agency, or any other private or governmental entity applying for or granted a site development or other permit.
48. "Private outfall"
means a stormwater conveyance element, e.g., a ditch or pipe, which discharges directly into a receiving water body that is exempt from flow control and does not divert water or upstream contributing area run-on from the natural discharge location of the site. Additional requirements for private outfalls are identified in the Sumner Development Specifications and Standard Details.
49. "Retention facilities"
means facilities designed to hold water for a length of time and then release it by evaporation, transpiration, or infiltration into the ground. Depending on infiltration rates, retention facilities may hold water longer than detention facilities.
50. "Rough grading"
means the preliminary clearing and shaping of a site.
51. "Runoff"
is the water that travels across the land surface and discharges to water bodies either directly or through a collection and conveyance system. See also "stormwater."
52. "SCS"
means the Soil Conservation Service, which is now the NRCS. Previously, the SCS issued several documents related to hydrology and hydraulics, such as soil maps, TR20, Computer Program for Project Formulation Hydrology, and TR55, Urban Hydrology for Small Watersheds.
53. "Sediment"
means soils or other surficial materials transported or deposited by the action of wind, water, ice, or gravity as a product of erosion.
54. "Sensitive areas"
means those areas defined and regulated under SMC Title 16. Sensitive areas shall not be used for stormwater management for proposed projects unless specifically allowed by SMC Title 16 and all required mitigation is provided.
55. "Single-family residential property or parcel"
means any property or parcel which contains only one residential unit. Properties or parcels which contain more than one residence or residential unit shall be classified as multifamily residential properties or parcels.
56. "Site"
means any tract, lot or parcel of land or combination of tracts, lots, or parcels of land which are in one ownership, or are contiguous and in diverse ownership, where development is to be performed as part of a unit, subdivision, or project.
57. "Short subdivision"
means the division or redivision of land into four or fewer lots, tracts, parcels, sites or divisions for the purpose of sale, lease or transfer of ownership.
58. "Slope grade"
means the ratio of horizontal run to vertical fall on a slope and shall be expressed as a ratio or as a percentage of a one-to-one ratio.
59. "Small municipal separate storm sewer system (small MS4)"a. b. c. d. e.
is a conveyance or system of conveyances including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, manmade channels, and/or storm drains which is:
Owned or operated by a city, town, county, district, association, or other public body created pursuant to state law having jurisdiction over disposal of sewage, industrial wastes, stormwater, or other wastes, including special districts under state law such as sewer districts, flood control districts, or drainage districts, or similar entity.
Designed or used for collecting or conveying stormwater.
Not a combined sewer system.
Not part of a publicly owned treatment works (POTW) as defined in 40 CFR 122.2.
Not defined as "large" or "medium" pursuant to 40 CFR 122.26(b)(4) and (7) or designed under 40 CFR 122.26(a)(1)(v).
Small MS4s include systems similar to separate storm sewer systems in municipalities such as: universities, large publicly owned hospitals, prison complexes, highways, and other thoroughfares. Storm sewer systems in very discrete areas such as individual buildings do not require coverage under this permit. |
Small MS4s do not include storm drain systems operated by nongovernmental entities such as: individual buildings, private schools, private colleges, private universities, and industrial and commercial entities. |
61. "Special district"
means a district formed and operated under the provisions of RCW Title 85. Special districts include diking districts; drainage districts; diking, drainage, and/or sewerage improvement districts; intercounty diking and drainage districts; consolidated diking districts, drainage districts, diking improvement districts, and/or drainage improvement districts; or flood control districts.
62. "Stabilization"
means the prevention of soil movement by any of various vegetative and/or structural means.
63. "Stabilize"
means to secure soil or deposited sediment so that the rate of erosion is minimized.
64. "Steep slopes"
means slopes which exceed 25 percent slope grade.
65. "Stormwater"
means runoff during and following precipitation and snowmelt events, including surface runoff and drainage.
66. "Stormwater comprehensive plan"
means the plan adopted by the city council for managing storm drainage and surface water runoff facilities and features within the city's drainage basins.
67. "Stormwater management"a. b.
means:
For quantitative control, a system of vegetative and/or structural measures that control the increased volume and rate of surface runoff caused by manmade changes to the land; and
For quality control, a system of vegetative, structural, and/or other measures that reduce or eliminate pollutants that might otherwise be carried by surface runoff.
68. "Stormwater management facilities"
means constructed facilities that collect, convey, treat, detain, or retain stormwater. Stormwater management facilities may include such elements as catch basins, manholes, pipes, LID BMPs, detention ponds, retention ponds, or other elements. Stormwater management facilities may be on private parcels, in public easements, or in public rights-of-way. Storm drainage systems with pipe and drainage structures are also considered stormwater management facilities for purposes of this chapter. Stormwater management facilities may also be referred to as "stormwater facilities."
69. "Stormwater management program (SWMP)"
means a set of actions and activities designed to reduce the discharge of pollutants from the regulated small MS4 to the maximum extent practicable and to protect water quality, and comprising the components listed in S5 or S6 of the NPDES Phase II permit and any additional actions necessary to meet the intent of these stormwater management regulations.
70. "Stormwater site plan"
means the comprehensive report containing all of the technical information and analysis necessary for the city to evaluate a proposed new development or redevelopment project for compliance with stormwater requirements. Contents of the stormwater site plan will vary with the type and size of the project, and individual site characteristics. The stormwater site plan includes a construction stormwater pollution prevention plan (construction SWPPP) and a permanent stormwater control plan. Guidance on preparing a stormwater site plan is contained in Volume I, Chapter 3 of the manual. The stormwater site plan shall be prepared by an engineer licensed by Washington State.
71. "Stripping"
means any activity which removes the vegetative surface cover including tree removal, clearing, grubbing and storage or removal of topsoil.
72. "Subdivision"
means the division or redivision of land into five or more lots, tracts, parcels, sites or divisions for the purpose of sale, lease or transfer of ownership, consistent with the provisions of this chapter; provided, that the term "subdivision" also includes the redivision of land into four or fewer lots, tracts, parcels sites or divisions for the purpose of sale, or transfer of ownership where such land has been short subdivided within the previous five years.
73. "Subject property"
means the tract of land which is the subject of the permit, and/or approval action, and/or inspection of violation, as defined by the full legal description of all parcels involved.
74. "System development charges"
are one-time charges assessed on new development or redevelopment to provide an equitable recovery of existing system infrastructure costs and to provide a source of revenue for future capital construction. System development charges are in addition to any actual cost incurred for system improvements or connection to an existing system as required for development.
75. "TESC"
means temporary erosion and sediment control measures to avoid adverse impacts to downstream water resources or on-site stormwater management facilities during construction. "TESC" also includes construction stormwater pollution prevention.
76. "UIC"
means the underground injection control rule promulgated by Ecology under chapter 173-218 WAC. Stormwater management facilities that are considered Class V wells under the UIC rule are usually shallow injection wells that inject fluids above the uppermost ground water aquifer. Some examples are dry wells, french drains, and drain fields. A UIC well is one of the following: (a) a bored, drilled, or driven shaft, or dug hole whose depth is greater than the largest surface dimension; (b) an improved sinkhole; or (c) a subsurface fluid distribution system. "Subsurface fluid distribution system" means an assemblage of perforated pipes, drain tiles, or other similar mechanisms intended to distribute fluids below the surface of the ground. Class V wells must be registered with Ecology in accordance with SMC § 13.48.350.
77. "Valley"
shall generally mean that portion within the incorporated limits of the city that drains through city owned, constructed storm drainage systems which outfalls directly to the Puyallup River or White River, which are defined by Ecology as flow control-exempt surface waters.
78. "Variance"
means the modification of the minimum stormwater management requirements for specific circumstances where strict adherence of the requirements would not fulfill the intent of these regulations and would result in unnecessary hardship.
79. "Waiver"
means the relinquishment from the stormwater management requirements by the city engineer for the specific development on a case-by-case review basis.
81. "Watercourse"
means any natural or artificial stream, river, creek, ditch, channel, swale, conduit, culvert, drain, gully, or ravine, in and including any area adjacent thereto, which is subject to inundation or conveys water by reason of runoff-producing precipitation events, overflow from adjacent areas, or flood water.
82. "Waters of the state"
includes those waters as defined as "waters of the United States" in 40 CFR 122.2 within the geographic boundaries of Washington State and "waters of the state" as defined in chapter 90.48 RCW, which includes lakes, rivers, ponds, streams, inland waters, underground waters, salt waters, and all other surface waters and watercourses within the jurisdiction of the state of Washington.
83. "Watershed"
means a geographic region within which water drains to a particular river, stream, or body of water. Watersheds can be as large as those identified and numbered by the state of Washington Water Resource Inventory Areas (WRIAs) as defined in chapter 173-500 WAC.
84. "Wetlands"
means those areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar areas. Wetlands do not include those artificial wetlands intentionally created from nonwetland sites, including, but not limited to, irrigation and drainage ditches, grass-lined swales, canals, detention facilities, wastewater treatment facilities, farm ponds, and landscape amenities, or those wetlands created after July 1, 1990, that were unintentionally created as a result of the construction of a road, street, or highway. Wetlands may include those artificial wetlands intentionally created from nonwetland areas to mitigate the conversion of wetlands. A wetland shall be delineated based on the U.S. Army Corps of Engineers Wetlands Delineation Manual, Technical Report Y-87-1, U.S. Army Engineers Waterways Experiment Station, Vicksburg, MS (1987).
(Ord. 2316 § 1 (part), 2010; Ord. 2356 § 11 (part), 2011; Ord. 2429 § 3, 2013; Ord. 2586 § 2 (part), 2016; Ord. 2826 § 1, 2022; Formerly 13.48.200 – 13.48.285)