Stormwater Management & LID Model Bylaw - Annotated
MODEL STORMWATER MANAGEMENT / LID BYLAW - Annotated
Section 1 Purpose and Authority
The purpose of this section is to protect, maintain, and enhance the public health, safety, and general welfare of the citizens of [name of Town/City] by establishing minimum requirements
and procedures to control the adverse impacts associated with stormwater runoff from new development and redevelopment.
The objectives of this section are:
Establish regulations for land development activities that preserve the health of water resources by reducing the adverse impacts to water quality from stormwater discharges to rivers,
lakes, reservoirs and streams in order to attain federal water quality standards;
Require that new development, redevelopment and all land conversion activities maintain the natural hydrologic characteristics of the land in order to reduce flooding, stream bank erosion,
siltation, nonpoint source pollution, property damage and the integrity of aquatic habitats and stream channels;
Prevent the discharge of pollutants, including hazardous chemicals, into stormwater runoff;
Minimize the volume and rate of stormwater which is discharged, to rivers, streams, reservoirs, lakes and combined sewers that flow from any site during construction and following development;
Prevent erosion and sedimentation from land development, and reduce stream channel erosion caused by increased runoff;
Require pre-development and post-development runoff volume and quality to be equivalent or improved by reducing runoff volumes, increasing infiltration and, improving runoff water quality.
Provide for the recharge of groundwater aquifers and maintain the base flow of streams;
Encourage the use of Low Impact Development (LID) practices such as reducing impervious cover, treating and infiltrating stormwater at the source, utilizing environmentally sensitive
site design and, the preservation of open space and natural areas, to the maximum extent practicable;
Coordinate site plans which include open space with the Town/City’s Open Space and Recreation Plan [or other community plans] to promote the connection of open space corridors.
Provide stormwater facilities that are attractive, maintain the natural integrity of the environment, and are designed to protect public safety;
Minimize damage to public and private property from flooding;
Establish maintenance provisions to ensure the stormwater treatment devices and facilities will continue to function as designed;
Establish procedures for the City/Town’s review of stormwater management plans, and for the City/Town’s inspection of approved stormwater controls; and,
Comply with state and federal statutes and regulations relating to stormwater discharges.
COMMENT: Palmer added the following objectives:
Inform the public about the value and benefits of groundwater recharge, pollution reduction and importance of clean water.
It is the intent that upon having followed the guidance of the Ordinance that the applicant will have done sufficient planning and documentation for Conservation Commission review (where
there is jurisdiction) and for U.S. Environmental Protection Agency review where a National Pollution Discharge Elimination System construction general permit is required.
The Authorized Permitting Agency shall administer and implement this [division/chapter/section].
COMMENT: Authorized permitting agency may vary depending on staffing capabilities and expertise of individual boards and departments. Most communities seek to incorporate Stormwater
Permit review alongside other permit application review.
Example (Westfield) - The board of public works or planning board or city council when an eligible project involves a zoning special permit, site plan approval or definitive subdivision
approval. When a project requires a Notice of Intent from the Conservation Commission and does not require review or permitting from any of the aforementioned boards and departments,
the Conservation Commission shall administer and implement this section.
In the case of a special permit, site plan approval and/or definitive subdivision approval said application for a stormwater management permit shall be incorporated and included as a
part of the applications for such other zoning and/or subdivision permit approvals, and shall be issued with and become a part of said other approved zoning and/or subdivision permits.
In the case of a Notice of Intent to the Conservation Commission, said application for a Stormwater Management Permit shall be incorporated and included as part of the applications if
none of the aforementioned permits are also triggered by the project.
Example (Palmer) – Authority shared between Department of Public Works and the Planning Board.
Authorized Administrative Agency is the Department of Public Works for all development projects involving new construction of single or two-family dwellings, and any additions to existing
single or two-family dwellings that result in ≤25% increase in floor area, vehicle traffic, parking, number of tenants, and/or number of employees. The Department of Public Works shall
also administer this Ordinance for
any land disturbance of one acre or more that does not fall under the Planning Board’s purview under this Ordinance. The Planning Board is the Authorized Administrative Agency for all
other land or building uses, and additions that result in >25% increase in floor area, vehicle traffic, parking, number of tenants, and/or number of employees. Authorized Administrative
Agency can include Building Inspector or Planning Board employees or agents designated to administer and implement this Ordinance by vote of either board.
Some communities also identify an Authorized Enforcement Agency if different than Authorized Administrative Entity (permit granting authority)
Example (Palmer) - Authorized Enforcement Agency The Zoning Enforcement Officer, Department of Public Works, Conservation Commission, Planning Board, Town Manager, and/or its employees
or agents.
Section 2 Definitions
The following definitions describe the meaning of the terms used in this ordinance:
Adverse impact: 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.
Authorized permitting agency: The [board of public works or planning board or conservation commission or city council] when an eligible project involves a [zoning special permit, site
plan approval or definitive subdivision approval or building permit or Notice of Intent].
COMMENT: See Section 1 Purpose and Authority above for further guidance on designating an Authorized permitting agency.
Best management practices (BMP): Stormwater management systems and facilities including structural or biological devices, manmade or natural, that temporarily store, treat, or convey
stormwater runoff to reduce flooding, remove pollutants, recharge groundwater, and provide other amenities. They can also be nonstructural practices that reduce pollutants at their source.
BMPs are further described in a stormwater design manual, Massachusetts Stormwater Handbook: Volume 2 Technical Guide for Compliance with the Massachusetts Stormwater Management Standards
(February 2008, Massachusetts Department of Environmental Protection),.Clean Water Act: The Federal Water Pollution Control Act (33 U.S.C. section 1251 et seq.) as hereinafter amended.
Construction activity: Disturbance of the ground by removal or moving of vegetative surface cover or topsoil, grading, excavation, clearing or filling.
Design storm: A rainfall event of specified size and return frequency that is used to calculate the runoff volume and peak discharge rate to a BMP.
Detention: The temporary storage of storm runoff in a BMP, which is used to control the "peak discharge" rates, and which provides gravity settling of pollutants.
Discharge of pollutants: The addition from any source of any pollutant or combination of pollutants into storm drain systems or into the waters of the United States or commonwealth from
any source.
Disturbance: Any land clearing, grading, bulldozing, digging or similar activities.
Drainage area: That area contributing runoff to a single point measured in a horizontal plane, which is enclosed by a ridgeline.
Drywell: Similar to an infiltration trench but smaller with inflow from a pipe; commonly covered with soil and used for drainage areas of less than 1 acre such as roadside inlets and
rooftops runoff.
Easement: A right of use over the property of another, generally for a specific purpose such as rights of access or rights regarding flowing waters or drainage.
Environmental Site Design (ESD): Site planning and layout that seeks to create pockets of development that avoid sensitive natural areas to prevent disruption of the natural hydrology
and habitat function of the site.
Flow attenuation: Prolonging the flow time of runoff to reduce the peak discharge.
Groundwater: All water beneath the surface of the ground not contained in a manmade structure.
Hydrology model: One of the following:
* TR-20, a watershed hydrology model developed by the Natural Resources Conservation Service Act that is used to route a design storm hydrograph through a pond;
* TR 55, or Technical Release 55, "Urban Hydrology for Small Watersheds" is a publication developed by the Natural Resources Conservation Service to calculate stormwater runoff and an
aid in designing detention basins; or,
* Hydrocad.
Illegal discharge: Any direct or indirect non-stormwater discharge to storm drain systems, except as specifically exempted in [insert reference to local Illicit Discharge Detection and
Elimination Bylaw]. The term does not include a discharge in compliance with an NPDES stormwater discharge permit or resulting from fire fighting activities exempted pursuant to aforementioned
bylaw.
Illicit connection: Any surface or subsurface drain or conveyance, which allows an illegal discharge into storm drain systems. Illicit connections include conveyances which allow a non-stormwater
discharge to storm drain systems including sewage, process wastewater or wash water and any connections from indoor drains, sinks or toilets, regardless of whether said connection was
previously allowed, permitted or approved before the effective date of this division.
Impervious surfaces: Developed areas, such as pavement or rooftops, which prevent the infiltration of water into the soil. Any material or structure on or above the ground that prevents
water from infiltrating the underlying soil.
Infiltration: The downward movement of water from the surface to the subsoil.
Infiltration trench: A stormwater management excavation filled with aggregate which removes both soluble and particulate pollutants. Trenches are not intended to trap coarse sediments.
Low Impact Development (LID): A set of approaches that seeks to mimic a site’s predevelopment hydrology using design techniques that infiltrate, filter, store, evaporate and detain runoff
close to its source. Instead of conveying, managing and/or treating stormwater in large, end-of-pipe facilities, LID utilizes small-scale, decentralized practices that infiltrate, treat,
evaporate, and transpire rain water and snow melt including bioretention areas, grassed swales, reducing impervious areas, preservation of open space, development density, lot size and
configuration, street design, parking design, and other structural stormwater treatment methods.
Municipal separate storm sewer system (MS4) or municipal storm drain system: The system of conveyances designed or used for collecting or conveying stormwater, including any road with
a drainage system, street, gutter, curb, inlet, piped storm drain, pumping facility, retention or detention basin, natural or manmade or altered drain channel, reservoir, and other drainage
structure that together comprise the storm drainage system owned and operated by the City of Westfield.
National Pollutant Discharge Elimination System (NPDES) stormwater discharge permit: A permit issued by the United States Environmental Protection Agency or jointly with the state that
authorizes the discharge of pollutants to waters of the United States.
Non-stormwater discharges: Any discharge to the storm drain systems not composed entirely of stormwater.
Outfall: The terminus of a storm drain or other stormwater structure where the contents are released.
Owner: Every person who alone, jointly or severally with others:
Has legal title to any building, structure or parcel of land; or,
Has care, charge or control of any building, structure, or parcel of land in any capacity including but not limited to, an agent, executor, executrix, administrator, administratrix,
trustee or guardian of the estate of the holder of legal title; or,
Lessee under a written lease agreement; or,
Mortgagee in possession; or,
Agent, trustee or other person appointed by the courts.
Peak discharge: The maximum instantaneous rate of flow during a storm, usually in reference to a specific design storm event
Permeable soils: Soil materials with a sufficiently rapid infiltration rate so as to greatly reduce or eliminate surface and stormwater runoff. These soils are generally classified as
NRCS hydrologic soil types A and B.
Person: Any individual, association, partnership, corporation, company, business, organization, trust, estate, administrative agency, public or quasi-public corporation or body, the
commonwealth or political subdivision thereof or the federal government, to the extent permitted by law and agent of such person.
Pollutant: Any element of property or sewage, agricultural, industrial or commercial waste, runoff, leachate, heated effluent, or other matter whether originating at a point or nonpoint
source, that is or may be introduced into any sewage treatment works or waters of the commonwealth. Pollutants shall include:
1. Paints, varnishes and solvents;
2. Oil and other automotive fluids;
3. Nonhazardous liquid and solid wastes and yard wastes;
4. Refuse, rubbish, garbage, litter, or other discarded or abandoned objects, ordnances, accumulations and floatables;
5. Pesticides, herbicides and fertilizers;
6. Hazardous materials and wastes; sewage, fecal coliform and pathogens;
7. Dissolved and particulate metals;
8. Animal wastes and residues;
9. Rock, sand, salt and soils;
10. Construction wastes and residues;
11. Noxious or offense matter of any kind.
Process water: Any water which, during manufacturing or processing, comes into direct contact with or results from the production or use of any material, intermediate product, finished
product or waste product.
Recharge: The process by which groundwater is replenished by precipitation through the percolation of runoff and surface water through the soil.
Retention: The holding of runoff in a basin without release except by means of evaporation, infiltration, or emergency bypass.
Start of construction: The first land-disturbing activity associated with a development, including land preparation such as: clearing and grubbing, grading and filling; installation
of streets and walkways; excavation for basements; footings, piers or foundations; erection of temporary forms; and installation of accessory buildings such as garages.
Stormwater: Runoff from precipitation or snow melt.
Storm drain system: The system of conveyances designed or used for collecting or conveying stormwater, including any road with a drainage system, street, gutter, curb, inlet, piped storm
drain, pumping facility, retention or detention basin, natural or manmade or altered drainage channel, reservoir, and other drainage structure that together comprise the storm drainage
system on public or private ways within the __________________.
Swale: A natural depression or wide shallow ditch used to temporarily store, route, or filter runoff.
Toxic or hazardous material or waste: Any material which, because of its quantity, concentration, chemical, corrosive, flammable, reactive, toxic, infectious or radioactive characteristics,
either separately or in combination with any substance or substances, constitutes a present or potential threat to human health, safety, welfare of to the environment. Toxic or hazardous
materials include any synthetic organic chemical, petroleum product, heavy metal, radioactive or infectious waste, acid and
alkali, and any substance defined as toxic or hazardous under M.G.L.A. c. 21C and c. 21E, and the regulations at 310 CMR 30.000 and 310 CMR 40.000.
Uncontaminated: Water containing no pollutants.
Watercourses: A natural or manmade channel through which water flows or a stream of water, including a river, brook or underground stream.
Waters of the commonwealth: All waters within the jurisdiction of the Commonwealth, including, without limitation, rivers, streams, lakes, ponds, springs, impoundments, estuaries, wetlands,
coastal waters and groundwater.
Wastewater: Any sanitary waste, sludge or septic tank or cesspool overflow and water that during manufacturing, cleaning or processing, comes into direct contact with or results from
the production or use of any raw material, intermediate product, finished product, byproduct or waste product.
Section 3 Applicability
COMMENT: NPDES only requires stormwater controls for sites disturbing one acre or more. Some communities have chosen to regulate additional uses and disturbances whether or not they
disturb one acre or more of land, such as the construction of single-family dwellings.
Example (Palmer) - …all land disturbance uses requiring a Special Permit, Site Plan Approval, and any residential uses, including residential dwellings that create land disturbances
and require a Building Permit. It shall also apply to all other land disturbances of one acre or more.”
NPDES requires communities to regulate stormwater discharges to the MS4. Some communities have chosen to regulate stormwater management at sites that do not discharge to the MS4 and
manage all stormwater on site in order to establish community wide standards for achieving improved water quality and groundwater recharge objectives.
Applicability
This [division/chapter/section] shall apply to stormwater entering the municipally-owned storm drainage system, and stormwater on private property for those activities identified in
Section 3 (B) whether or not flows enter the municipally owned storm drainage system.
Permit or Waiver Required
Prior to the commencement of construction for any proposed development listed below, a stormwater management permit, or a waiver of the requirement for a stormwater management permit,
must be approved by the applicable authorized permitting agency. No person shall, on or after the effective date of the section, initiate any land clearing and grubbing, land grading,
earth moving or development activities without first complying with this ordinance. The following uses and activities shall be required to submit drainage reports, plans, construction
drawings, specifications and as-constructed information in conformance with the requirements of this [division/chapter/section]:
1. Multifamily residential developments involving four or more units;
2. Any new commercial, industrial, and institutional structures under the same ownership, with at least 5,000 square feet of gross floor area, 10,000 square feet of impervious surface,
or that require ten or more parking spaces;
3. Redevelopment or additions to existing commercial, industrial, and institutional uses which result in an additional impervious surface area or gross floor area of greater than 5,000
square feet, or which results in an increase of ten or more parking spaces.
4. Construction activities and subdivisions disturbing greater than or equal to one acre.
5. Development or redevelopment involving multiple separate activities in discontinuous locations or on different schedules if the activities are part of a larger common plan of development
that together disturbs one or more acres.
Exemptions
The following uses and activities are exempt from the requirements for submittal and approval of a Stormwater Management Plan. All exempt uses and activities must still comply with the
purposes and the stormwater performance standards of this [division/chapter/section]. Failure of an exempt use or activity to comply with the provisions of this [division/chapter/section]
shall be interpreted as a violation and exempt status revoked.
1. Any agricultural activity which is consistent with an approved soil conservation plan prepared or approved by the Natural Resources Conservation Service;
2. Any logging which is consistent with a timber management plan approved under the Forest Cutting Practices Act by Massachusetts Department of Environmental Management;
3. Developments that do not disturb more than one acre of land, provided that they are not part of a larger common development plan;
COMMENT: Some communities have chosen to regulate disturbances smaller than one acre such as the construction of single-family dwellings. For those communities, this exemption is not
appropriate.
4. Repairs to any stormwater treatment system deemed necessary by the [town/city Department of Public Works/Highway Department];
5. Any emergency activity that is immediately necessary for the protection of life, property or the environment, as determined by the [Department of Public Works/Highway Department];
and
6. Any uses and activities not specified in subsection (3)(B).
D. Stormwater Design Manual
A stormwater design manual, Massachusetts Stormwater Handbook: Volume 2 Technical Guide for Compliance with Massachusetts Stormwater Management Standard (Massachusetts Department of
Environmental Protection, February 2008), as updated or amended, is hereby incorporated by reference
as part of this [division/chapter/section], and shall furnish additional policy, criteria and information including specifications and standards, for the proper implementation of the
requirements of this division. This manual includes a list of acceptable stormwater treatment practices, including the specific design criteria for each stormwater practice. The manual
may be updated and expanded from time to time, based on improvements in engineering, science, monitoring and local maintenance experience, at the discretion of the Massachusetts Department
of Environmental Protection. Stormwater treatment practices that are designed and constructed in accordance with these design and sizing criteria will be presumed to meet the minimum
water quality performance standards.
Section 4 Permit Procedures and Requirements
A. Permit required
No owner or operator may apply for nor be issued any of the building, grading, or other land development permits required for land disturbance activities as described in subsection (3)
above, and no owner shall commence any such land disturbance activities, without the prior approval of a stormwater management permit from the authorized permitting agency and meeting
the requirements of this [division/chapter/section].
B. Application
Application for approval of a stormwater management permit shall include the following:
1. A Stormwater Management Plan which shall contain sufficient information to describe the nature and purpose of the proposed development (see Section 5 Stormwater Management Plan
Contents below). The plan shall serve as the basis for all subsequent construction.
2. Supporting computations, drawings, and sufficient information describing the manner, location, and type of measures in which stormwater runoff and erosion will be managed for the
entire development during and after construction.
3. Ongoing maintenance agreement.
4. Nonrefundable permit fee.
COMMENT: Fees are discussed in detail under (H) below.
The applicant may request, and the authorized permitting agency may grant, a waiver from any information requirements it judges to be unnecessary to the review of a particular plan.
C. Procedures for review and approval of stormwater permits
1. A stormwater management plan (or an application for waiver) shall be submitted to the authorized permitting agency for review and approval for any proposed development specified
in subsection (4). [Number of] copies of the stormwater management plan shall be submitted (along with all other documents required for any zoning or subdivision permits/approvals when
required).
2. The procedures for review and approval of stormwater management plans shall be consistent with review procedures of the authorized permitting agency, as appropriate to the use.
3. The authorized permitting agency shall refer copies of the stormwater management plan to [the city engineer, department of public works, planning department, water department, health
department, conservation commission, building department and the gas and electric department] for review, and shall consider any comments submitted by said departments during the review
period.
4. The authorized permitting agency shall hold a public hearing. [The planning board and city council shall hold their public hearing as part of their special permit, site plan approval
and/or definitive subdivision approval process. The board of public works shall hold its public hearing within 45 days of the receipt of a complete application and shall take final
action within 45 days from the close of the hearing unless such time is extended by agreement between the applicant and board. Notice of the public hearing shall be given by publication
in a local paper of general circulation, by posting and by first-class mailings to abutters at least seven days prior to the hearing.]
COMMENT: It is recommended that the procedures of the public hearing and amount of time for final action be consistent with other permits issued by the authorized permitting authority.
D. Criteria for review of stormwater management plans
In addition to other criteria used by the authorized permitting agency in making permit decisions, for the uses specified in this [division/section/chapter], said authorized permitting
agency must also find that the stormwater management plan submitted with the permit application meets the following criteria:
1. The stormwater management plan is consistent with the purposes and objectives of this division in subsection (1);
2. The stormwater management plan meets the performance standards described in subsection (6); and,
3. The stormwater management plan meets the design requirements in subsection (7).
E. Authorized permitting agency action
The authorized permitting agency's action, rendered in writing, shall consist of either:
1. Approval of the stormwater management permit application based upon determination that the proposed stormwater management plan meets the purposes in subsection (1), the standards
in subsection (6), and is in compliance with the requirements set forth in this [division/section/chapter]; or,
2. Approval of the stormwater management permit application subject to any conditions, modifications or restrictions required by the board which will ensure that the project meets
the purposes in subsection (1) and the performance standards in subsection (6); or,
3. Disapproval of the stormwater management permit application based upon a determination that the proposed stormwater management plan, as submitted, does not meet the purposes in
subsection (1) and the performance standards in subsection (6) to adequately protect water resources, as set forth in this [division/section/chapter].
Failure of the authorized permitting agency to take final action upon an application within the time specified above shall be deemed to be approval of said application. Upon certification
by the city clerk that the allowed time has passed without authorized permitting agency action, the authorized permitting agency must issue a stormwater management permit.
F. Inspections
No plan will be approved without adequate provision for inspection of the property before development activity commences. The applicant shall arrange with the authorized permitting agency
(or its appointed agent) for scheduling the following inspections, or upon request by the authorized permitting agency, shall have a qualified third party as determined by the [City
Engineer /DPW Superintendent] perform the inspections and submit a detailed report as to their findings:
1. Initial inspection prior to approval of any plan;
2. Erosion control inspections after site clearing, rough grading and final grading to ensure erosion control practices are in accord with the plan;
3. Bury inspection prior to backfilling of any underground drainage or stormwater conveyance structures; and,
4. Final inspection when all work, including construction of stormwater management facilities and landscaping have been completed.
Inspection reporting shall either approve it or notify the applicant in writing in what respects there has been a failure to comply with the requirements of the approved plan. Any portion
of the work which does not comply shall be promptly corrected by the applicant or the applicant will be subject to the bonding provisions of subsection (9) or the penalty provisions
of subsection (10). The authorized permitting agency or its agent may conduct random inspections to ensure effective control of erosion and sedimentation during all phases of construction.
G. Right of entry for inspection
The filing of a Stormwater Management Permit application shall be deemed as the property owner's permission to the authorized permitting agency, or its agent, for the right to enter
the property at reasonable times and in a reasonable manner for the purpose of the inspection. This includes the right to enter a property when it has a reasonable basis to believe that
a violation of this [division/section/chapter] is occurring or has occurred, and to enter when necessary for abatement of a public nuisance or correction a violation.
H. Stormwater permit fees
COMMENT: Fee structures vary greatly and are determined by the availability of each communities staffing and funding resources to oversee permit applications, review plans, perform inspections,
and seek enforcement if needed. Some communities set a fee for the review of the application and a
separate fee for inspections. One fee rather than two separate fees with separate accounting needs is recommended to provide for both application review and inspection services.
If the bylaw establishes a single authorized permitting authority, the fees can be set via regulations adopted by that board. However, if there are multiple permit granting authorities,
the fee should be established in the bylaw.
Communities also have the right to require applicants to pay reasonable costs for outside professional expertise employed by the municipality to assist in review of an application in
accordance with MGL Chapter 44, Section 53G.
Example (Westfield) - For permits issued by the Planning Board, Conservation Commission or City Council, no additional fee is required. For permits issued by the Board of Public Works
the fee for review of any land development application shall be based on the amount of land to be disturbed at the site and the fee structure established by the board.
The stormwater permit fee is as follows _____________________ .
Section 5 Contents of the stormwater management plan
COMMENT: For communities seeking to regulate disturbances from single-family dwellings, a less technical stormwater management plan is required. For all other activities regulated under
this bylaw, a more detailed stormwater management plan is required.
1. A Stormwater Management Plan submitted with the permit application shall contain sufficient information for the Authorized Permitting Agency to evaluate the environmental impact,
effectiveness and acceptability of the measures proposed for reducing adverse impacts from construction stormwater runoff and post-development stormwater runoff. This plan shall comply
with the criteria established in the [division/section/chapter] and must be submitted with the stamp and signature of a professional Engineer (PE) licensed in the Commonwealth of Massachusetts.
2. For land altering activity subject to this [division/section/chapter] involving construction of a single-family dwelling, where “approval is not required” (ANR), as defined in the
Subdivision Control Act, and that disturbs less than 1 acre of land, the Stormwater Management Plan shall include:
a. A locus map;
b. The existing zoning and land use at the site;
c. The proposed land use;
d. The location(s) of existing and proposed easements;
e. The location of existing and proposed utilities;
f. The site's existing and proposed topography with contours at two-foot intervals unless the applicant can demonstrate that the proposed activity will meet the requirements of this
[division/section/chapter] without such information;
g. Proposed limits of disturbance;
h. Estimate of the total area expected to be disturbed by excavation, grading or other construction activities;
i. Description of existing site hydrology;
j. Description and location of existing stormwater conveyances, impoundments, and wetlands on or adjacent to the site or into which stormwater flows;
k. Description of the proposed management systems post-construction for runoff from impervious surfaces including roofs and driveways and the locations of any foundation drains, curtain
drains, or other site features that serve to collect and convey stormwater and their outfalls; and
l. Description of erosion and sediment control measures during construction.
3. For all other land altering activity subject to this [division/section/chapter], the Stormwater Management Plan shall fully describe the project in narrative, drawings and calculations
and shall include:
a. A locus map;
b. The existing zoning, and land use at the site;
c. The proposed land use and area of disturbance;
d. The location(s) of existing and proposed easements;
e. The location of existing and proposed utilities;
f. The site's existing and proposed topography with contours at two-foot intervals;
g. Description of existing site hydrology;
h. A description and location of existing stormwater conveyances, impoundments, and wetlands on or adjacent to the site or into which storm water flows;
i. A delineation of 100-year flood plains, if applicable;
j. Estimated seasonal high groundwater elevation (November to April) in areas to be used for stormwater retention, detention, or infiltration;
k. The existing and proposed vegetation and ground surfaces with runoff coefficient for each;
l. A drainage area map showing pre and post-construction watershed boundaries, drainage area and storm water flow paths;
m. A description and drawings of all components of the proposed drainage system including:
(1) Locations, cross sections, and profiles of all brooks, streams, drainage swales and their method of stabilization;
(2) All measures for the detention, retention or infiltration of water;
(3) All measures for the protection of water quality;
(4) The structural details for all components of the proposed drainage systems and storm water management facilities;
(5) Notes on drawings specifying materials to be used, construction specifications, and typicals;
(6) Expected hydrology with supporting calculations;
(7) Proposed improvements including location of buildings or other structures, impervious surfaces, and drainage facilities, if applicable;
(8) A description of construction and waste materials expected to be stored on site, and a description of controls to reduce pollutants from these materials including storage practices
to minimize exposure of the materials to stormwater, and spill prevention and response;
(9) Timing, schedules, and sequence of development including clearing, stripping, rough grading, construction, final grading, and vegetative stabilization; and,
(10) A maintenance schedule for the period of construction.
n. Environmentally sensitive site design and LID analysis demonstrating application of principles, where feasible, through:
(1) reduced impervious surface coverage through street design, street width, parking design, and sidewalks;
(2) open space/tree retention;
(3) increased development density in exchange for open space protection in other areas of site; and,
(4) incorporation of decentralized, naturalized LID stormwater management systems to treat and infiltrate stormwater at the source.
Section 6 Stormwater management performance standards
A. Minimum control requirements
Projects that require a permit under this [division/section/chapter] must meet the standards of the Massachusetts Stormwater Management Standards. These standards are:
1. No new stormwater conveyances (e.g. outfalls) may discharge untreated stormwater directly to or cause erosion in wetlands or water of the commonwealth.
2. Stormwater management systems must be designed so that post-development peak discharge rates do not exceed predevelopment peak discharge rates.
3. Loss of annual recharge to groundwater should be minimized through the use of infiltration measures, including but not limited to environmentally sensitive site design, low impact
development techniques, stormwater best management practices, and good operation and maintenance, to the maximum extent practicable. The annual recharge from the post-development site
should approximate the annual recharge rate from the predevelopment or existing site conditions, based on soil types.
4. Stormwater management systems must be designed to remove 80 percent of the average annual load (post development conditions) of total suspended solids (TSS).
5. For land uses with higher potential pollutant loads, source control and pollution prevention shall be implemented in accordance with the Massachusetts Stormwater Handbook to eliminate
or reduce the discharge of stormwater runoff from such land uses to the maximum extent practicable. The use of infiltration practices without pretreatment is prohibited.
6. Stormwater discharges within the Zone II or Interim Welhead Protection Area of a public water supply, and stormwater discharges near or to any other critical area, require the
use of the specific source control and pollution prevention measures and the specific structural stormwater best management practices determined to be suitable for managing discharges
to such area, as provided by the Massachusetts Stormwater Handbook.
7. Redevelopment of previously developed sites must meet the stormwater management standards to the maximum extent practicable. However, if it is not practicable to meet all the standards,
new (retrofitted or expanded) stormwater management systems must be designed to improve existing conditions.
8. Erosion and sediment controls must be implemented to prevent impacts during disturbance and construction activities.
9. All stormwater management systems must have an operation and maintenance plan to ensure that systems function as designed.
When the proposed discharge may have an impact upon a sensitive receptor, including streams, wetlands, vernal pools, storm sewers, and/or combined sewers, the authorized permitting agency
may require an increase in these minimum requirements, based on existing stormwater system capacity.
B. Stormwater management measures
1. Stormwater management measures shall be required to satisfy the minimum control requirements and shall be implemented in the following order of preference:
a. Infiltration, flow attenuation, and pollutant removal of runoff on site to existing areas with grass, trees, and similar vegetation and through the use of open vegetated swales
and natural depressions;
b. Use of stormwater on site to replace water used in industrial processes or for irrigation;
c. Stormwater detention structures for the temporary storage of runoff which is designed so as not to create a permanent pool of water; and
d. Stormwater retention structures for the permanent storage of runoff by means of a permanent pool of water; and,
e. Detention and evaporation of stormwater on rooftops or in parking lots.
2. Infiltration practices shall be utilized to reduce runoff volume increases. A combination of successive practices may be used to achieve the applicable minimum control requirements.
3. Best management practices shall be employed to minimize pollutants in stormwater runoff prior to discharge into a separate storm drainage system or water body.
4. All stormwater management facilities shall be designed to provide an emergency overflow system, and incorporate measures to provide a non-erosive velocity of flow along its length
and at any outfall.
5. The designed release rate of any stormwater structure shall be modified if any increase in flooding or stream channel erosion would result at a downstream dam, highway, structure,
or normal point of restricted stream flow.
COMMENT: Prioritize LID approach first - decentralized, watershed-wide approaches that treat and infiltrate stormwater at the source rather than large end of pipe systems.
Example (Palmer) - Stormwater best management practices that mimic natural hydrology (i.e., nonstructural and small-scale upland management approaches) should be considered as first-line
practices. Given appropriate soils and conditions, all opportunities to use nonstructural and small-scale upland management designs must be exhausted prior to exploring end-of-pipe
stormwater management approaches.
C. Specific design criteria
Additional policy, criteria, and information including specifications and design standards may be found in the stormwater design manual.
1. All projects subject to this [division/section/chapter] must consider the following environmentally sensitive site design and Low Impact Development (LID) techniques:
(a) Identify, map and preserve the site’s natural features and environmentally sensitive areas such as wetlands, native vegetation, mature trees, slopes, drainage ways, permeable soils,
flood plains, woodlands, and prime agricultural soils to the maximum extent practicable;
(b) Minimize grading and clearing;
(c) Delineate potential building envelopes, avoiding environmental resource areas and appropriate buffers by clustering buildings and reducing building footprints;
(d) Develop methods to minimize impervious surfaces, and protect and preserve open space. Reduce impervious surfaces where ever possible through alternative street design, such as omission
of curbs and use of narrower streets, shared driveways and through the use of shared parking areas;
(e) Manage runoff using smaller, decentralized, low-tech stormwater management techniques to treat and recharge stormwater close to the source;
Lengthen flow paths and maximize sheet flow;
(f) Use nonstructural, low-tech methods including open drainage systems, disconnection of roof runoff and street sweeping where possible;
(g) Use native plant vegetation in buffer strips and in rain gardens (small planted depressions that can trap and filter runoff);
(h) Use of vegetation that does not require irrigation during periods of drought; and,
(i) Integrate the following techniques into the site design to create a hydrologically functional site, including but not limited to the following:
(1)Grass swales along roads;
(2) Rain gardens;
(3) Buffer strips;
(4) Use of roof gardens where practicable;
(5) Use of amended soils that will store, filter and infiltrate runoff;
(6) Bioretention areas;
(7) Use of rain barrels and other cisterns to provide additional stormwater storage; and,
(8) Use of permeable pavement.
2. Infiltration systems
(a) Infiltration systems shall be equipped with clean stone and or filter fabric adjacent to the soil or other sediment removal mechanisms;
(b) Infiltration systems greater than three feet deep shall be located at least ten feet from basement walls;
(c) Due to the potential for groundwater contamination, dry wells shall not be an acceptable method for management of runoff containing pollutants;
(d) Infiltration systems designed to handle runoff from commercial or industrial impervious parking areas shall be a minimum of 100 feet from any drinking water supply well;
(e) Infiltration systems shall not be used as sediment control basins during construction unless specific plans are included to restore or improve the basin surface;
(f) Infiltration basins shall be constructed with a three foot minimum separation between the bottom of the structure and the seasonal high groundwater elevation, as determined by
a certified soil evaluator; and,
(g) Provisions shall be made for safe overflow passage, in the event of a storm which exceeds the capacity of an infiltration system.
3. Retention and detention ponds
Retention and detention ponds shall be designed and constructed in accordance with the criteria of the Massachusetts Stormwater Handbook: Volume 2 Technical Guide for Compliance with
Massachusetts Stormwater Management Standard (Massachusetts Department of Environmental Protection, February 2008), as updated or amended.
4. Natural topography and land cover
The applicant shall give consideration in any plan to incorporating the use of natural topography and land cover such as natural swales, and depressions as they exist prior to development
to the degree that they can accommodate the additional flow of water.
5. Swales
The authorized permitting agency shall give preference to the use of swales in place of the traditional use of curbs and gutters based on a case by case review of stormwater management
plans by the city engineer and authorized permitting agency.
6. Public safety
The applicant shall consider public safety in the design of any stormwater facilities. The banks of detention, retention, and infiltration basins shall be sloped at a gentle grade into
the water as a safeguard against personal injury, to encourage the growth of vegetation and to allow the alternate flooding and exposure of areas along the shore. Basins shall have a
four-to-one slope to a depth two feet below the control elevation. Side slopes must be stabilized and planted with vegetation to prevent erosion and provide pollutant removal. The banks
of detention and retention areas shall be designed with sinuous rather than straight shorelines so that the length of the shoreline is maximized, thus offering more space for the growth
of vegetation;
7. Where a stormwater management plan involves direction of some or all runoff off of the site, it shall be the responsibility of the applicant to obtain from adjacent property owners
any easements or other necessary property interests concerning flowage of water. Approval of a stormwater management plan does not create or affect any such rights.
8. All applicants for projects which involve the storage or use of hazardous chemicals shall incorporate handling and storage "best management practices" that prevent such chemicals
from contaminating runoff discharged from a site into infiltration systems, receiving water bodies or storm drains, and shall include a list of such chemicals in the application and
the Material Safety Data Sheets (MSDS) for each listed chemical
9. Runoff from parking lots and streets shall be treated by oil and water separators or other controls to remove oil and sediment;
10. The basic design criteria methodologies and construction specifications, subject to the approval of the authorized permitting agency and review and recommendation of the city engineer,
shall be those generally found in the most current edition of the Massachusetts Stormwater Handbook: Volume 2 Technical Guide for Compliance with Massachusetts Stormwater Management
Standard (Massachusetts Department of Environmental Protection, February 2008), as updated or amended.
D. Design requirements for construction related activities
The design requirements for construction related activities in the Stormwater Management Plan are:
1. Minimize total area of disturbance;
2. Sequence construction activities to minimize simultaneous areas of disturbance;
3. Minimize peak rate of runoff in accordance with the Massachusetts DEP Stormwater Policy;
4. Minimize soil erosion and control sedimentation during construction. Prevention of erosion is preferred over sedimentation control;
5. Divert uncontaminated water around disturbed areas;
6. Maximize groundwater recharge;
7. Install and maintain all erosion and sediment control measures in accordance with the manufacturer’s specifications and good engineering practices;
8. Prevent off-site transport of sediment including off-site vehicle tracking of sediment;
9. Protect and manage on- and off-site material storage areas (overburden and stockpiles of dirt, borrow areas, or other areas used solely by the permitted project are considered a
part of the project);
10. Comply with applicable federal, state and local laws and regulations including waste disposal, sanitary sewer or septic system regulations, and air quality requirements, including
dust control;
11. Prevent adverse impact from the proposed activities to habitats mapped by the Massachusetts Natural Heritage and Endangered Species Program as endangered, threatened or of special
concern, estimated habitats of rare wildlife and certified vernal pools, and priority habitats of rare species;
12. Institute interim and permanent stabilization measures. The measures shall be instituted on a disturbed area as soon as practicable but no more than 14 days after construction
activity has temporarily or permanently ceased on that portion of the site; and,
13. Properly manage on-site construction and waste materials.
E. Maintenance
1. Operation, maintenance and inspection agreement
(a) Prior to issuance of any building permit for which stormwater management is required, the authorized permitting agency shall require the applicant or owner to execute an operation,
maintenance and inspection agreement binding on all subsequent owners of land served by the private stormwater management facility. The agreement shall be designed to ensure that water
quality standards are met in all seasons and
throughout the life of the system. Such agreement shall provide for access to the facility at reasonable times for regular inspections by the [town/city] or its authorized representative
and for regular or special assessments of property owners to ensure that the facility is maintained in proper working condition to meet design standards and any provision established.
The agreement shall include:
(1) The name(s) of the owner(s) for all components of the system.
(2) Maintenance agreements that specify:
i. The names and addresses of the person(s) responsible for operation and maintenance
ii. The person(s) responsible for financing maintenance and emergency repairs.
iii. A maintenance schedule for all drainage structures, including swales and ponds.
iv. A list of easements with the purpose and location of each.
v. The signature(s) of the owner(s).
2. Stormwater management easements as necessary for:
(a) Access for facility inspections and maintenance;
(b) Preservation of stormwater runoff conveyance, infiltration, and detention areas and facilities, including flood routes for the 100-year storm event.
(c) Direct maintenance access by heavy equipment to structures requiring regular cleanout.
3. Stormwater management easement requirements
(a) Purpose of each easement shall be specified in the maintenance agreement signed by the property owner.
(b) Stormwater management easements are required for all areas used for off-site stormwater control, unless a waiver is granted by the city.
(c) Easements shall be recorded with the registry of deeds prior to issuance of a certificate of completion.
4. Changes to operation and maintenance plans
(a) The owner(s) of the stormwater management system must notify the authorized enforcement agency of changes in ownership or assignment of financial responsibility.
(b) The maintenance schedule in the maintenance agreement may be amended to achieve the purposes of this bylaw by mutual agreement of the authorized permitting agency and the responsible
parties. Amendments must be in writing and signed by all responsible parties. Responsible parties must include owner(s), persons with financial responsibility, and persons with operational
responsibility.
(c) The agreement shall be recorded by the applicant and/or owner in the land records of the registry of deeds. Proof of such recording shall be filed by the applicant and/or owner
with the authorized permitting agency.
(d) The agreement shall also provide that, if after notice by the city engineer to correct a violation requiring maintenance work, satisfactory corrections are not made by the owner(s)
within 30 days, by the authority, granted inter alia, Amendment Article 89 to Article II of the Massachusetts Constitution, Chapter 294 of the Acts of 1920, as amended, Sections one
through twenty-four of Chapter 83 of the General Laws of the
Commonwealth of Massachusetts, the City may seek civil penalties of up to $5,000 for each day of violation of this division, and/or seek remedy in Superior Court.
COMMENT: Amendment Article 89 to Article II of the Massachusetts Constitution, Chapter 294 of the Acts of 1920, as amended, Sections one through twenty-four of Chapter 83 of the General
Laws of the Commonwealth of Massachusetts, allows municipalities to seek civil penalties of up to $5,000 for each day for stormwater related violations, and/or seek remedy in Superior
Court.
5. Maintenance responsibility
(a) The owner of the property on which work has been done pursuant to this division for private stormwater management facilities, or any other person or agent in control of such property,
shall maintain in good condition and promptly repair and restore all grade surfaces, walls, drains, dams and structures, vegetation, erosion and sediment control measures and other protective
devices. Such repairs or restoration and maintenance shall be in accordance with approved plans.
(b) A maintenance schedule shall be developed for the life of any stormwater management facility and shall state the maintenance to be completed, the time period for completion, and
who shall be legally responsible to perform the maintenance. This maintenance schedule shall be printed on the stormwater management plan.
(c) Records of installation and maintenance.
(d) Failure to maintain practices.
F. Performance bond
The authorized permitting agency shall require from the developer a surety or cash bond, irrevocable letter of credit, or other means of security acceptable to the authorized permitting
agency prior to the issuance of any building permit for the construction of a development requiring a stormwater management facility. The amount of the security shall not be less than
the total estimated construction cost of the stormwater management facility. The bond so required in this subsection shall include provisions relative to forfeiture for failure to complete
work specified in the approved stormwater management plan, compliance with all of the provisions of this division and other applicable laws and regulations, and any time limitations.
The bond shall not be fully released without a final inspection of the completed work by the [city engineer], submission of" as-built" plans, and certification of completion by the authorized
permitting agency of the stormwater management facilities being in compliance with the approved plan and the provisions of this division.
G. Enforcement and penalties
1. Violations
Any development activity that has commenced or is conducted contrary to this division may be restrained by injunction or otherwise abated in a manner provided by law.
2. Notice of violation
When the authorized permitting agency or its designated agent determines that an activity is not being carried out in accordance with the requirements of this division, it shall issue
a written notice of violation to the owner of the property. The notice of violation shall contain:
(a) The name and address of the owner applicant;
(b) The address when available or the description of the building, structure, or land upon which the violation is occurring;
(c) A statement specifying the nature of the violation;
(d) A description of the remedial measures necessary to bring the development activity into compliance with this division and a time schedule for the completion of such remedial action;
(e) A statement of the penalty or penalties that shall or may be assessed against the person to whom the notice of violation is directed;
(f) A statement that the determination of violation may be appealed to the Authorized Permitting Authority by filing a written notice of appeal within 15 days of service of notice
of violation.
3. Stop work orders
Persons receiving a notice of violations will be required to halt all construction activities. This "stop work order" will be in effect until the authorized permitting agency or its
designated agent confirms that the development activity is in compliance and the violation has been satisfactorily addressed. Failure to address a notice of violation in a timely manner
can result in civil, criminal, or monetary penalties in accordance with the enforcement measures authorized in this division.
4. Criminal and civil penalties
Any person who violates any provision of this division, valid regulation, or the terms or conditions in any permit or order prescribed or issued there under, shall in accordance with
Section 10 of Chapter 83 of the Massachusetts General Laws, be subject to a civil penalty of $5,000 for each day such violation occurs or continues, which may be assessed in an action
brought on behalf of the [city/town] in any court of competent jurisdiction together with such equitable relief as is appropriate.
5. Noncriminal disposition
As an alternative to criminal prosecution or civil action, the city may elect to utilize the noncriminal disposition procedure set forth in [Town/City Bylaw/Ordinance]. The [Department
of Public Works] shall be the enforcing entity. The penalty for the first violation shall be up to $100.00. The penalty for the second violation shall be up to $200.00. The penalty for
the third and subsequent violations shall be $300.00. Each day or part thereof that such violation occurs or continues shall constitute a separate offense.
COMMENT: Not all municipalities have adopted Noncriminal Disposition procedures. If your community has not done so, these procedures would need to be enacted separately as part of the
General Bylaws/City Ordinance in order to utilize this alternative mode of enforcement.
6. Restoration of lands
Any violator may be required to restore land to its undisturbed condition. In the event that restoration is not undertaken within a reasonable time after notice, the [Department of Public
Works] may take necessary corrective action, the cost of which shall become a lien upon the property until paid.
7. Holds on occupancy permits
Occupation permits will not be granted until corrections to all stormwater practices have been made and accepted by the [Department of Public Works].
8. Severability
The invalidity of any section or provision of this section shall not invalidate any other section or provision thereof.