ARTICLE XXI 21

STORMWATER MANAGEMENT

1. PURPOSE AND OBJECTIVE

A. The purpose of this bylaw is to protect public health, safety, general welfare, and environment by controlling the adverse effects of construction site stormwater runoff and post-construction runoff from new development and redevelopment. The construction phase and post-development impacts of stormwater runoff quantity and quality can adversely affect public safety, public and private property, surface water drinking water supplies, groundwater drinking water supplies, recreation, aquatic habitats, fish and other aquatic life, property values, and other uses of lands and waters.

B. The objectives of this bylaw are to:

1. Protect water resources;

2. Comply with state and federal statutes and regulations relating to stormwater discharges;

3. Prevent and reduce pollutants from entering the Canton’s municipal separate storm sewer system (MS4);

4. Establish minimum construction and post construction stormwater management standards and design criteria for the regulation and control of stormwater runoff quantity and quality;

5. Require the use of nonstructural stormwater management, stormwater better site design practices or “low-impact development practices”, such as reducing impervious cover and the preservation of greenspace and other natural areas, unless infeasible

6. Establish provisions for the long-term responsibility for, and maintenance of, structural stormwater control facilities and nonstructural stormwater best management practices to ensure that they continue to function as designed are maintained;

7. Establish administrative procedures and fees for the submission, review, approval or disapproval of stormwater management plans, and for the inspection of approved active projects, and long-term follow up;

21 Inserted under article 16, ATM May 2, 2007; deleted in its entirety and replaced under article 2, STM June 22, 2020 190

8. Ensure that there is an adequate funding mechanism, including surety, for the proper review of applications, inspection of projects, and assurance of the long-term maintenance of stormwater facilities implemented as part of this Bylaw;

9. Recognize Canton’s legal authority to ensure compliance with the provisions of this bylaw through inspection, monitoring, and enforcement.

10. Require, through issuance of a Stormwater Management Permit, and through an inspection program described in the Stormwater Regulations, the proper management of construction phase soil erosion and sediment control to minimize or eliminate erosion and maintain sediment on site so that it is not transported in stormwater and allowed to discharge to a water of the U.S through Canton’s drainage system, as required by the Town of Canton’s Small Municipal Separate Storm Sewer System (MS4) Permit issued by the United States Environmental Protection Administration (EPA).

2. APPLICABILITY

A. No person may undertake a construction activity or land disturbance, including clearing, grading, excavation or redevelopment that will disturb or alter equal to or greater than 20,000 square feet without a Stormwater Management Permit approved by a majority of the Stormwater Authority members or as otherwise provided in this Bylaw. Any person that fails to follow the requirements of a Stormwater Management Permit and the related Erosion Control Plan, and Operations and Maintenance Plan, shall be in violation of this Bylaw.

1. This Bylaw shall be applicable to all new development and redevelopment, including, but not limited to, site plan applications, subdivision applications, grading applications, land use conversion applications, any activity that will result in an increased amount of stormwater runoff or pollutants flowing from a parcel of land, or any activity that will alter the drainage characteristics of a parcel of land, unless exempt pursuant to Section 2.C of this Bylaw. All new development and redevelopment under the jurisdiction of this Bylaw as prescribed in this Bylaw shall be required to obtain a Stormwater Management Permit.

2. The holder of a Stormwater Management Permit must employ sediment and erosion control at the permitted construction site in accordance with an Erosion Control Plan approved by the Stormwater Authority. The Erosion Control Plan must be prepared in accordance with the Canton Stormwater Regulations and the “Massachusetts Erosion and Sediment Control Guidelines for Urban and Suburban Areas”, May 2003 (or as modified).

B. Hotspots - An alteration, redevelopment, or conversion of land use to a hotspot such as, without limitation: auto salvage yards, auto fueling facilities, fleet 191

storage yards, commercial parking lots with high intensity use, road salt storage areas, commercial nurseries and landscaping businesses, outdoor storage and loading areas of hazardous substances, shall require a Stormwater Management Permit.

C. Exemptions – The following activities are exempt from the requirement to obtain a Stormwater Management Permit:

1. Any activity that will alter an area less than 20,000 square feet, with the exception of any projects which file for a Stormwater Management Permit between the effective date of this Bylaw and prior to August 30, 2020, for which the threshold will be 5,000 square feet of disturbance or less than 25% of a contiguous property, whichever is less. This exception may not be applied for contiguous properties held in common ownership at the time of adoption of this Bylaw that may have been previously subdivided and/or are attributed to multiple separate owners.

2. Normal maintenance and improvement of land in agricultural use as defined by the Wetlands Protection Act.

3. Maintenance of existing landscaping, gardens or lawn areas associated with a single family dwelling.

4. Repair or replacement of an existing roof of a single-family dwelling.

5. The construction of any fence that will not alter existing terrain or drainage patterns.

6. Construction or repair of utilities (gas, water, electric, telephone, etc.) other than drainage, which will not alter terrain, ground cover, or drainage patterns.

7. Emergency repairs to any stormwater management facility or practice that poses a threat to public health or safety, or as deemed necessary by the Conservation Commission.

8. Any work or projects for which all necessary approvals and permits have been issued before the effective date of this Bylaw.

D. Nothing in this Bylaw is intended to replace the requirements of the Town of Canton Zoning Bylaw, Flood Plain Overlay District, the Town of Canton Wetlands Protection Bylaw, the Consolidated Drainage Bylaw or any other Bylaw that may be adopted by the Town of Canton. Any activity subject to the provisions of the above cited Bylaws must comply with the specifications of each. 192

Nothing in this Bylaw is intended to replace the requirements of construction site operators to comply with the terms and conditions of EPA’s Construction General Permit.

3. AUTHORITY

This Bylaw is adopted under authority granted by the Home Rule Amendment of the Massachusetts Constitution, the Home Rule statutes, and pursuant to the regulations of the federal Clean Water Act found at 40 CFR 122.34.

4. ADMINISTRATION

A. The Conservation Commission or its authorized Agent(s) shall administer, implement and enforce this Bylaw. Any powers granted to or duties imposed upon the Commission may be delegated in writing by the Commission to its employees or agents.

B. Stormwater Regulations. The Conservation Commission may adopt, and periodically amend, rules and regulations relating to the terms, conditions, definitions, enforcement (including sanctions for violation), fees (including application, inspection, and/or consultant fees), procedures and administration of this Stormwater Management Bylaw by majority vote of the Commission after conducting a public hearing to receive comments on any proposed revisions. Such hearing dates shall be advertised in a newspaper of general local circulation, at least seven (7) days prior to the hearing date. After public notice and public hearing, the Commission may promulgate rules and regulations to effectuate the purposes of this Bylaw. Failure by the Commission to promulgate such rules and regulations or a legal declaration of their invalidity by a court shall not act to suspend or invalidate the effect of this Bylaw. As revisions to this Bylaw may precede updates to the Stormwater Regulations, in case of conflict, this Bylaw shall govern and the Conservation Commission and its Agent may waive provisions of the Stormwater Regulations which are in conflict with this Bylaw. Applicants should consult with the Conservation Agent.

C. Massachusetts Stormwater Handbook. The Conservation Commission, at a minimum, may utilize the policy, criteria and information including specifications and standards of the latest edition of the Massachusetts Stormwater Handbook for execution of the provisions of this Bylaw. This Handbook includes a list of acceptable stormwater treatment practices, including the specific design criteria for each stormwater practice. The Handbook may be updated and expanded periodically, based on improvements in engineering, science, monitoring, and local maintenance experience. Unless specifically altered in the Stormwater Regulations, stormwater management practices that 193

are designed, constructed, and maintained in accordance with the Handbook will be presumed to be protective of Massachusetts water quality standards.

D. Stormwater Management Permit. The Conservation Commission shall have the authority to adopt rules and regulations further defining the Stormwater Management Permit (SMP) for projects as described in section 2.A.

E. Actions by the Conservation Commission. The Conservation Commission may take any of the following actions as a result of an application for a Stormwater Management Permit as more specifically defined as part of Stormwater Regulations promulgated pursuant to this Bylaw: Approval, Approval with Conditions, Denial, or Denial without Prejudice.

F. Appeals of Action by the Conservation Commission. A decision of the Conservation Commission shall be final. Further relief of a decision by the Conservation Commission made under this Bylaw shall be appealed to a court of competent jurisdiction.

G. Stormwater Utility. The Select Board may adopt, pursuant to any applicable law or Bylaw, a Stormwater Utility pursuant to M.G.L. Chapter 83 Section 16 and Chapter 40 Section 1A. The Select Board shall administer, implement, and enforce this Utility. Failure by the Canton Select Board to promulgate such a Stormwater Utility through its Regulations or a legal declaration of its invalidity by a court shall not act to suspend or invalidate the effect of the other provisions of this Bylaw.

H. Stormwater Credit System. The Canton Conservation Commission may adopt, through the Regulations authorized by this Stormwater Management Bylaw, a Stormwater Credit System. This credit system will allow applicants the option, if approved by the Commission, to take credit for the use of stormwater low impact design practices to reduce some of the requirements specified in the criteria section of the Regulations. Failure by the Commission to promulgate such a credit system through its Regulations or a legal declaration of the invalidity of the credit system by a court shall not act to suspend or invalidate the effect of the other provisions of this Bylaw.

5. PROCEDURES

Permit Procedures and Requirements shall be defined and included as part of any rules and regulations promulgated as permitted under Section 4.B. of this Bylaw. As revisions to this Bylaw may precede updates to the Stormwater Regulations, in case of conflict, this Bylaw shall govern and the Conservation Commission and its Agent may waive provisions of the Stormwater Regulations 194

which are in conflict with this Bylaw. Applicants should consult with the Conservation Agent.

6. ENFORCEMENT

The Conservation Commission, or an authorized agent of the Conservation Commission shall enforce this Bylaw, regulations, orders, violation notices, and enforcement orders, and may pursue all civil and criminal remedies for such violations. Enforcement shall be further defined and included as part of any Stormwater regulations promulgated as permitted under Section 4.B. of this Bylaw.

7. COORDINATION WITH OTHER TOWN DEPARTMENTS

Any person filing a permit application with the Conservation Commission shall submit a copy thereof at the same time, by email, certified mail, or hand delivery, to the Select Board, Planning Board, DPW Engineering Department, Board of Appeals, Board of Health, and the Building Inspector. The person filing such application shall at the same time submit to the Conservation Commission a written notice that these copies have been submitted to these other departments. The Conservation Commission shall not take final action on an application until such boards and officials have had fourteen calendar days from their receipt to submit written comments, if any, to the Conservation Commission. The applicant shall have the right to receive such written comments, if any, and to respond to them, if desired, prior to final action.

8. DEFINITIONS

The following definitions shall apply in the interpretation and implementation of this Bylaw. Additional definitions may be adopted by separate regulation:

A. ALTER: Any activity which will measurably change the ability of a ground surface area to absorb water or will change existing surface drainage patterns. Alter may be similarly represented as “alteration of drainage characteristics,” and “conducting land disturbing activities.”

B. BEST MANAGEMENT PRACTICE (BMP): Structural, non-structural and managerial techniques that are recognized to be the most effective and practical means to prevent and/or reduce increases in stormwater volumes and flows, reduce point source and nonpoint source pollution, and promote stormwater quality and protection of the environment. “Structural” BMPs are devices that are engineered and constructed to provide temporary storage and treatment of stormwater runoff. “Nonstructural” BMPs use natural measures to reduce pollution levels, do not require extensive construction efforts (e.g. policies

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or procedures such as enhanced street sweeping), and/or promote pollutant reduction by eliminating the pollutant source.

C. EROSION AND SEDIMENT CONTROL PLAN: A document containing narrative, drawings, and details developed by a qualified professional engineer (PE) or a Certified Professional in Erosion and Sediment Control (CPESC) which includes best management practices or equivalent measures designed to control surface runoff, erosion and sedimentation during pre-construction and construction related land disturbing activities in accordance with requirements of this bylaw.

D. EROSION: The wearing away of the land surface by natural or artificial forces such as wind, water, ice, gravity, or vehicle traffic and the subsequent detachment and transportation of soil particles.

E. GRADING: Changing the level or shape of the ground surface.

F. HOTSPOT: Land uses or activities with higher potential pollutant loadings, such as auto salvage yards, auto fueling facilities, fleet storage yards, commercial parking lots with high intensity use, road salt storage areas, commercial nurseries and landscaping, outdoor storage and loading areas of hazardous substances, or marinas.

G. LAND-DISTURBING ACTIVITY (also referred to as LAND DISTURBANCE, DISTURBANCE OF LAND and LAND ALTERATION): Any activity that causes a change in the position or location of soil, sand, rock, gravel, or similar earth material; results in an increased amount of runoff or pollutants; measurably changes the ability of a ground surface to absorb waters, involves clearing (of soil, trees or vegetation) and grading, and/or results in an alteration of drainage characteristics.

H. LOW IMPACT DESIGN (formerly Better Site Design): Site design approaches and techniques that can reduce a site’s impact on the watershed through the use of nonstructural stormwater management practices. Also known as environmentally sensitive design, low impact design includes conserving and protecting natural areas and greenspace, reducing impervious cover, and using natural features for stormwater management.

I. MASSACHUSETTS STORMWATER MANAGEMENT STANDARDS: The Standards issued by the Massachusetts Department of Environmental Protection, as further defined in the Massachusetts Stormwater Handbook, as amended, that coordinates the requirements prescribed by state regulations promulgated under the authority of the Massachusetts Wetlands Protection Act G.L. c. 131 § 40 and Massachusetts Clean Waters Act G.L. c. 21, §. 23-56. The Standards address stormwater impacts through implementation of performance 196

standards to reduce or prevent pollutants from reaching water bodies and control the quantity of runoff from a site.

J. MS4 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 man-made or altered drainage channel, reservoir, and other drainage structure that together comprise the storm drainage system owned or operated by the Town of Canton.

K. NEW DEVELOPMENT: Any construction or land disturbance of a parcel of land that is currently in a natural vegetated state and does not contain alteration by man-made activities

L. NONPOINT SOURCE POLLUTION: Pollution from many diffuse sources caused by rainfall or snowmelt moving over and through the ground. As the runoff moves, it picks up and carries away natural and human-made pollutants, finally depositing them into water resource areas.

M. NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES) STORMWATER DISCHARGE PERMIT: A permit issued by United States Environmental Protection Agency or jointly with the Commonwealth of Massachusetts that authorizes the discharge of pollutants to waters of the United States.

N. OPERATION AND MAINTENANCE PLAN: A plan setting up the functional, financial and organizational mechanisms for the ongoing operation and maintenance of a stormwater management system to insure that it continues to function as designed.

O. PERSON: Any individual, group of individuals, association, partnership, corporation, company, business organization, trust, estate, the Commonwealth or political subdivision thereof to the extent subject to Town Bylaws, administrative agency, public or quasi-public corporation or body, the Town of Canton and any other legal entity, its legal representatives, agents, or assigns.

P. POLLUTANT: Any element or property of 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, watercourse, or Waters of the Commonwealth. Pollutants include, but are not limited to:

i. Paints, varnishes, and solvents;

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ii. Oil and other automotive fluids;

iii. Nonhazardous liquid and solid wastes and yard wastes;

iv. Refuse, rubbish, garbage, litter, or other discarded or abandoned objects, ordnance, accumulations and floatables;

v. Pesticides, herbicides, and fertilizers;

vi. Hazardous materials and wastes;

vii. Sewage, fecal coliform and pathogens;

viii. Dissolved and particulate metals;

ix. Animal wastes;

x. Rock, sand, salt, soils;

xi. Construction wastes and residues; and

xii. Noxious or offensive matter of any kind.

Q. PRE-CONSTRUCTION: All activities in preparation of construction.

R. PRE-DEVELOPMENT: The conditions that exist at the time that plans for the development of a tract of land are submitted to the Canton Conservation Commission. Where phased development or plan approval occurs (preliminary grading, roads and utilities, etc.), the existing conditions at the time prior to the first plan submission shall establish pre-development conditions.

S. RECHARGE: The process by which groundwater is replenished by precipitation through the percolation of runoff and surface into the soil.

T. REDEVELOPMENT: Development, rehabilitation, expansion, demolition, construction, land alteration, or phased projects that disturb the ground surface, including impervious surfaces, on previously developed sites. The creation of new areas of impervious surface or new areas of land disturbance on a site constitutes development, not redevelopment, even where such activities are part of a common plan which also involves redevelopment. Redevelopment includes maintenance and improvement of existing roadways including widening less than a single lane, adding shoulders, correcting substandard intersections, improving existing drainage systems and repaving; and remedial projects specifically designed to provide improved stormwater management such as projects to separate storm drains and sanitary sewers and stormwater retrofit projects.

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U. SEDIMENT: Mineral or organic soil material that is transported by wind or water, from its original to another location; the product of erosion processes.

V. SEDIMENTATION: The process or act of deposition of sediment.

W. SITE: Any lot or parcel of land or area of property where land-disturbing activities are, were, or will be performed.

X. STORMWATER AUTHORITY: The Town of Canton Conservation Commission or its authorized agent(s). The Conservation Commission is responsible for coordinating the review, approval and permit process as defined in this Bylaw. Other Boards and/or departments participate in the review process as defined in the Stormwater Regulations adopted by the Conservation Commission.

Y. STORMWATER MANAGEMENT FEE: a charge for the use of the Stormwater Management Services.

Z. STORMWATER UTILITY: A specific management structure for the Stormwater Management Fee, in which a municipal utility is established to administer the fee and the Stormwater Management Program similar to a water or sewer utility.

AA. 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, groundwater, and Waters of the United States as defined under the Federal Clean Water Act as hereafter amended.

9. SEVERABILITY

The invalidity of any section, provision, paragraph, sentence, or clause of this Bylaw shall not invalidate any other section, provision, paragraph, sentence, or clause thereof, nor shall it invalidate any permit or determination that previously has been issued.

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