This chapter shall be known and may be cited as the "Montgomery
Township Stormwater Management Ordinance."
The Board of Supervisors finds that:
A.
Inadequate management of accelerated stormwater runoff resulting
from development and redevelopment throughout a watershed increases
flood flows and velocities, contributes to erosion and sedimentation,
overtaxes the carrying capacity of streams and storm sewers, greatly
increases the cost of public facilities to convey and manage stormwater,
undermines floodplain management and flood reduction efforts in upstream
and downstream communities, reduces groundwater recharge, and threatens
public health and safety, and increases nonpoint source pollution
of water resources.
B.
Inadequate planning and management of stormwater runoff 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 streambeds and stream banks, thereby elevating sedimentation),
destroying aquatic habitat, and elevating aquatic pollutant concentrations
and loadings such as sediments, nutrients, heavy metals, and pathogens.
C.
A comprehensive program of stormwater management (SWM), including
reasonable regulation of development and activities causing accelerated
runoff, is fundamental to the public health, safety, welfare, and
the protection of the people of the Township and all the people of
the commonwealth, their resources, and the environment.
D.
Stormwater is an important water resource by providing groundwater
recharge for water supplies and base flow of streams, which also protects
and maintains surface water quality.
E.
Public education on the control of pollution from stormwater is an
essential component in successfully addressing stormwater.
F.
Federal and state regulations require certain municipalities to implement
a program of stormwater controls. These municipalities are required
to obtain a permit for stormwater discharges from their separate storm
sewer systems under the National Pollutant Discharge Elimination System
(NPDES).
G.
Impacts from stormwater runoff can be minimized by using project
designs that maintain the natural hydrologic regime and sustain high
water quality, groundwater recharge, stream baseflow, and aquatic
ecosystems.
H.
Nonstormwater discharges to municipal separate storm sewer systems
can contribute to pollution of waters of the commonwealth.
I.
The use of green infrastructure and low-impact development (LID)
are intended to address the root cause of water quality impairment
by using systems and practices which use or mimic natural processes
to: 1) infiltrate and recharge; 2) evapotranspire; and/or 3) harvest
and use precipitation near where it falls to earth. Green infrastructure
practices and LID contribute to the restoration or maintenance of
predevelopment hydrology.
The purpose of this chapter is to promote the public health, safety, and welfare within the Township by maintaining the natural hydrologic regime and by minimizing the harms and maximizing the benefits described in § 206-2, through provisions designed to:
A.
Meet legal water quality requirements under state law, including
regulations at 25 Pa. Code Chapter 93 to protect, maintain, reclaim,
and restore the existing and designated uses of the waters of this
commonwealth.
B.
Minimize increases in stormwater volume and control peak flows.
C.
Minimize impervious surfaces.
D.
Provide review procedures and performance standards for stormwater
planning and management.
E.
Preserve the natural drainage systems.
F.
Manage stormwater impacts close to the runoff source, reduce runoff
volumes, and mimic predevelopment hydrology.
G.
Focus on infiltration of stormwater to maintain groundwater recharge,
to prevent degradation of surface and groundwater quality, and to
otherwise protect water resources.
H.
Preserve and restore the flood-carrying capacity of streams.
I.
Prevent scour and erosion of stream banks and streambeds.
J.
Provide standards to meet National Pollution Discharge Elimination
System (NPDES) permit requirements.
K.
Address certain requirements of the municipal separate stormwater
sewer system (MS4) NPDES Phase II stormwater regulations.
L.
Provide for proper operation and maintenance of all stormwater management
facilities and best management practices (BMPs) that are implemented
in the Township.
M.
Implement the requirements of the Neshaminy Creek Watershed Act 167
Stormwater Management Plan (includes Little Neshaminy Creek Watershed).
N.
Implement the requirements of the Wissahickon Creek Watershed Act
167 Plan.
O.
Provide procedures and performance standards for stormwater planning
and management.
P.
Maintain groundwater recharge to prevent degradation of surface and
groundwater quality and to otherwise protect water resources.
The Township is empowered to regulate land use activities that
affect runoff, surface, and groundwater quality and quantity by the
authority of:
A.
All regulated activities and all activities that may affect stormwater
runoff, including land development and earth disturbance activity,
are subject to regulation by this chapter.
B.
Regulated activities include, but are not limited to:
(1)
Land development;
(2)
Subdivisions;
(3)
Prohibited or polluted discharges;
(4)
Alteration of the natural hydrologic regime;
(5)
Construction or reconstruction of, or addition of new impervious
or semipervious surfaces (i.e., driveways, parking lots, roads, etc.),
except for reconstruction of roads where there is no increase in impervious
surface;
(6)
Construction of new buildings or additions to existing buildings;
(7)
Redevelopment;
(8)
Diversion piping or encroachments in any natural or man-made channel;
(9)
Nonstructural and structural stormwater management best management
practices (BMPs) or appurtenances thereto;
(10)
Earth disturbance activities of equal to or greater than 1,000
square feet;
(11)
Any of the above-regulated activities which were approved more
than five years prior to the effective date of this chapter and resubmitted
for municipal approval.
A.
Table 206-6.1 summarizes the exemptions from certain requirements in this chapter. "Proposed impervious surface" in Table 206-6.1 includes new, additional, or replacement impervious surface/cover. "Repaving" existing surfaces without reconstruction (see § 206-13) does not constitute replacement.
|
Table 206-6.1: Exemption Thresholds
| |||||
|---|---|---|---|---|---|
|
Chapter Article or Section
|
Type of Project
|
Less Than 5,000 Square Feet Disturbed Area and Proposed Impervious
Surface
|
Equal to or Greater Than 5,000 Square Feet Disturbed Area
| ||
|
0 to 1,000 Square Feet
|
More Than 1,000 to Less Than 5,000 Square Feet
|
Equal to or Greater Than 5,000 Square Feet
| |||
|
Article IV, SWM site plan requirements
|
All development
|
Exempt
|
Not exempt (except residential activity)
|
Not exempt
|
Not exempt
|
|
Appendix F, Nonengineered small project site plan
|
Only residential development applicable
|
Exempt
|
Not exempt
|
Not applicable
|
Not applicable
|
|
§ 206-17, Volume control requirements
|
All development
|
Not applicable
|
Not exempt
|
Not exempt
|
Not exempt
|
|
§ 206-18, Peak rate control requirements
|
All development
|
Exempt
|
Exempt
|
Not exempt
|
Not exempt
|
|
§ 206-19, Nonstructural project design requirements
|
All development
|
Exempt
|
Not exempt
|
Not exempt
|
Not exempt
|
|
§ 206-20, Stream bank erosion requirements
|
All development
|
Exempt
|
Not exempt
|
Not exempt
|
Not exempt
|
|
§ 206-16, Erosion and sediment pollution control requirements
|
See Table 206-6.2
| ||||
|
Article V, Inspections
|
All development
|
Exempt
|
Not exempt
|
Not exempt
|
Not exempt
|
|
Article VII, Maintenance responsibilities
|
All development
|
Exempt
|
Not exempt
|
Not exempt
|
Not exempt
|
|
Table 206-6.2: Erosion and Sediment Pollution Control Exemption
Thresholds
| |||||
|---|---|---|---|---|---|
|
Disturbed Area
|
Written E&S Plan
|
E&S Plan Review for Adequacy by MCCD
|
E&S Plan Review for Adequacy by the Township
|
NPDES Permit
|
Written PCSM Plan Required
|
|
0 to 1,000 square feet
|
Not required unless in HQ or EV watershed, or is a condition
of other state permit
|
Exempt
|
Exempt
|
Exempt
|
Exempt
|
|
1,000 to 5,000 square feet
|
Required by the Township
|
Exempt
|
Not exempt
|
Exempt
|
Per Table 206-6.1
|
|
5,000 square feet to less than 1 acre
|
Required by the Township
|
Required by the Township
|
Not exempt
|
Exempt
|
Per Table 206-6.1
|
|
1 acre or greater
|
Required by MCCD
|
Required by MCCD
|
Not exempt
|
Not exempt
|
Per Table 206-6.1
|
B.
Agricultural activity is exempt from the peak rate control requirements
and SWM site plan preparation requirements of this chapter provided
the activities are performed according to the requirements of 25 Pa.
Code Chapter 102.
C.
Forest management and timber operations are exempt from the peak
rate control requirements and SWM site plan preparation requirements
of this chapter provided the activities are performed according to
the requirements of 25 Pa. Code Chapter 102.
D.
Any aspect of BMP maintenance to an existing SWM system made in accordance
with plans and specifications approved by the Township is exempt.
E.
The use of land for gardening and/or landscaping for home consumption
is exempt from the requirements of this chapter.
G.
Infiltration exemptions.
(1)
Depth to limiting zone: A minimum of two feet of soil suitable for
infiltration must exist between the invert of the infiltration BMP
and the top of the nearest limiting zone. Otherwise, the volume control
requirement shall not be applied to the development site, and the
entire volume must be treated.
H.
Hotspots.
(1)
Stormwater hotspots: Appendix D[1] contains a list of types of hotspots that may be recognized
by the Township. If a site is a potential hotspot, it has important
implications for how stormwater is managed. First and foremost, untreated
stormwater runoff from hotspots concentrated into a collection system
shall not be recharged into groundwater where it may contaminate water
supplies. Therefore, the volume control requirement shall not be applied
to development sites that lie within a hotspot (the entire volume
must still be treated). Second, a greater level of stormwater treatment
shall be applied at hotspot sites to prevent pollutant washoff after
construction. The Environmental Protection Agency's (EPA) National
Pollutant Discharge Elimination System (NPDES) stormwater program
requires some industrial sites to prepare and implement a stormwater
pollution prevention plan.
[1]
Editor's Note: Appendix D is included as an attachment
to this chapter.
(2)
Rate of infiltration: When infiltration is not feasible due to poor
infiltration rates or hotspot, the water quality volume must be treated
by an approved SMP.
I.
Additional exemption criteria.
(1)
Exemption responsibilities: An exemption shall not relieve the applicant
from implementing such measures as are necessary to protect public
health, safety, and property.
(2)
Drainage problems: Where drainage problems are documented or known
to exist downstream of or is expected from the proposed activity,
the Township may deny exemptions.
(3)
Exemptions are limited to specific portions of this chapter.
(4)
HQ and EV streams: The Township may deny exemptions in high quality
(HQ) or exceptional value (EV) waters and source water protection
areas (SWPA).
(5)
For a development taking place in stages, the entire development
plan must be used in determining compliance with these exemption criteria.
The starting point from which to consider tracts as "parent tracts"
in which future subdivisions and respective impervious area computations
are cumulatively considered shall be the date of the municipal adoption
of the original Montgomery Township Stormwater Management Plan Ordinance
(May 12, 2014).
(a)
For example: If a property owner in Montgomery Township proposes a 300-square-foot shed after adoption of the municipal stormwater management ordinance, that property owner would be exempt from site plan and peak rate control requirements. If, at a later date, the property owner proposes to construct a garage and driveway adding an additional 1,300 square feet of impervious surface, the applicant would be required to submit a SWM site plan or small project SWM site plan (or if applicable a fee-in-lieu of alternative for small projects) in accordance with Article IV demonstrating the stormwater control requirements for the total impervious surface of 1,600 square feet.
J.
The Township may deny or revoke any exemption pursuant to this section
at any time for any project that the Township believes may pose a
threat to public health, safety, property or the environment.
Approvals issued pursuant to this chapter do not relieve the
applicant of the responsibility to secure required permits or approvals
for activities regulated by any other applicable code, rule, act,
or ordinance.
Any other ordinance provision(s) or regulation of the Township
inconsistent with any of the provisions of this chapter is hereby
repealed to the extent of the inconsistency only.
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 taken by a board, agency or employee
of the Township purporting to validate such a violation.
B.
Waivers or modifications of the requirements of this chapter may
be approved by the Township if enforcement will exact undue hardship
because of peculiar conditions pertaining to the land in question,
provided that the modifications will not be contrary to the public
interest and that the purpose of the chapter is preserved. Cost or
financial burden shall not be considered a hardship. Modification
may be considered if an alternative standard or approach will provide
equal or better achievement of the purpose of the chapter. A request
for modifications shall be in writing and accompany the stormwater
management site plan submission. The request shall provide the facts
on which the request is based, the provision(s) of the chapter involved
and the proposed modification.
C.
No waiver or modification of any regulated stormwater activity involving
earth disturbance greater than or equal to one acre may be granted
by the Township unless that action is approved in advance by the Department
of Environmental Protection (DEP) or the delegated county conservation
district.
The appendixes listed below are incorporated herein by reference,
as amended, and shall be updated periodically as necessary by resolution
of the Township Board of Supervisors:
(1)
Appendix A, Stormwater Management Design Criteria.
(2)
Appendix B, Low-Impact Development Practices.
(3)
Appendix C, Disconnected Impervious Area.
(4)
Appendix D, Hotspots.
(5)
Appendix E, West Nile Virus Guidance.
(6)
Appendix F, Small Project Stormwater Management Site Plan.
(7)
Appendix G, Nonstructural Project Design Checklist.
(8)
Appendix H, Riparian Buffer Trail Guidelines.
(9)
Appendix I, References.
