Model Stormwater Management/ Lid Ordinance/Bylaw

MODEL STORMWATER MANAGEMENT/ LID ORDINANCE/BYLAW

Pioneer Valley Planning Commission

March 17, 2011

Section 1 Purposeand Authority

1. 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 runofffrom new development and redevelopment.

1. The objectives of this section are:

1. 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;

1. 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;

1. Prevent the discharge of pollutants, including hazardous chemicals, into stormwater runoff;

1. 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;

1. Prevent erosion and sedimentation from land development, and reduce stream channel erosion caused by increased runoff;

1. Require post-development runoff volume and quality to be equivalent to or an improvement on pre-development runoff conditions by reducing runoff volumes, increasing infiltration and, improving runoff water quality.

1. Provide for the recharge of groundwater aquifers and maintain the base flow of streams;

1. 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;

1. 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.

1. Provide stormwater facilities that are attractive, maintain the natural integrity of the environment, and are designed to protect public safety;

1. Minimize damage to public and private property from flooding;

1. Establish maintenance provisions to ensure the stormwater treatment devices and facilities will continue to function as designed;

1. Establish procedures for the [City/Town’s] review of stormwater management plans, and for the [City/Town’s] inspection of approved stormwater controls; and,

1. 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.

1. 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 concurrent with other permit application review.

Example #1 (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 beincorporated and included as part of the applications if none of the aforementioned permits are also triggered by the project.

Example #2 (Holyoke) - The City Engineer shall administer and implement this division. A Building Permit shall not be issued without a Stormwater Permit. For projects that do not trigger review by any City Board or Commission, the City Engineer shall independently conduct an administrative Stormwater Management Plan review and issue a Stormwater Permit. For projects that trigger Subdivision, Special Permit, Site Plan, Conservation Commission or any other Review, the City Engineer’s review of the Stormwater Management Plan shall take place concurrently, and the appropriate reviewing Board or Commission shall approve the Stormwater Management Plan pursuant to recommendations made by the City Engineer. Once approved by the

Example #3 (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 conveystormwater 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): Stormwater management techniques appropriate to the size, scale, and location of the development proposal that limit off-site stormwater runoff (both peak and non-peak flows) to levels substantially similar to natural hydrology (or, in the case of a redevelopment site, that reduce such flows from pre-existing conditions), by emphasizing decentralized management practices and the protection of on-site natural features. LID approaches 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:

1. Has legal title to any building, structure or parcel of land; or,
2. 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,
3. Lessee under a written lease agreement; or,
4. Mortgagee in possession; or,
5. 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.”