[HISTORY: Adopted 5-13-2008 Annual Town Meeting, Art. 27. Amendments noted where applicable.]
GENERAL REFERENCES
Subdivision rules and regulations — See Ch. 192.
The purpose of this bylaw is to protect, maintain and enhance the public health, safety, environment and general welfare by establishing minimum requirements to control the adverse effects of stormwater runoff and erosion. Through proper management of stormwater, sediment and erosion controls this bylaw safeguards the public health, safety, environment and general welfare of the public. This bylaw serves to protect water and groundwater resources, promote groundwater recharge and prevent flooding.
The requirements of this bylaw shall apply to existing development, new development, and redevelopment projects to minimize adverse impacts of erosion and stormwater runoff off site and downstream which would be borne by abutters, townspeople and the general public. The Board of Selectmen may delegate from time to time certain duties described in this bylaw to designees who will act on its behalf for the purposes of enforcement.
a. 
Runoff. All runoff from impervious surfaces of a lot shall be recharged on that lot. Runoff shall be diverted towards areas covered with vegetation for surface infiltration.
b. 
Stormwater. All stormwater drainage shall be contained on the development site and away from wetland resources. All stormwater shall be treated on site unless there is a public benefit to connecting to another drainage system or allowing stormwater to flow off site. Commercial development shall be required to handle calculated flows from a 25-year storm.
c. 
Drains. In no instance shall roof drains, subsurface drains, or overflow drains of any kind be directed to the public road layout.
d. 
Post-construction stormwater management. For new development or redevelopment, any construction activities or land alteration resulting in total earth disturbance equal to or greater than one (1) acre [or activities that are part of a larger common plan of development disturbing greater than one (1) acre], shall meet the following stormwater management requirements:
[Added 5-13-2019 ATM by Art. 47]
1. 
Low impact development (LID) site planning and design strategies must be used to the maximum extent feasible.
2. 
The design of treatment and infiltration practices should follow the guidance in Volume 2 of the Massachusetts Stormwater Handbook, as amended, or other state approved BMP design guidance.
3. 
Stormwater management systems on new development sites shall be designed to:
i. 
Not allow new stormwater conveyances to discharge untreated stormwater in accordance with Massachusetts Stormwater Handbook Standard 1;
ii. 
Control peak runoff rates in accordance with Massachusetts Stormwater Handbook Standard 2;
iii. 
Recharge groundwater in accordance with Massachusetts Stormwater Handbook Standard 3;
iv. 
Eliminate or reduce the discharge of pollutants from land uses with higher pollutant loads as defined in the Massachusetts Stormwater Handbook in accordance with Massachusetts Stormwater Handbook Standard 5;
v. 
Protect Zone II or interim wellhead protection areas of public water supplies in accordance with Massachusetts Stormwater Handbook Standard 6;
vi. 
Implement long term maintenance practices in accordance with Massachusetts Stormwater Handbook Standard 9; and
vii. 
Require that all stormwater management systems be designed to:
1) 
Retain the volume of runoff equivalent to, or greater than, one (1.0) inch multiplied by the total post-construction impervious surface area on the site and/or
2) 
Remove 90% of the average annual load of total suspended solids (TSS) generated from the total post-construction impervious area on the site and 60% of the average annual load of total phosphorus (TP) generated from the total post-construction impervious surface area on the site. Pollutant removal shall be calculated consistent with EPA Region 1's BMP Performance Extrapolation Tool or other BMP performance evaluation tool provided by EPA Region 1, where available.
4. 
Stormwater management systems on redevelopment sites shall meet the following sections to the maximum extent feasible:
i. 
Be designed to meet Massachusetts Stormwater Standard Volumes 1-3 and the pretreatment and structural best management practices requirements of Massachusetts Stormwater Standards 5 and 6.
ii. 
Stormwater management systems on redevelopment sites shall also improve existing conditions by requiring that stormwater management systems be designed to:
1) 
Retain the volume of runoff equivalent to, or greater than, 0.80 inch multiplied by the total post-construction impervious surface area on the site and/or
2) 
Remove 80% of the average annual post-construction load of total suspended solids (TSS) generated from the total post-construction impervious area on the site and 50% of the average annual load of total phosphorus (TP) generated from the total post-construction impervious surface area on the site. Pollutant removal shall be calculated consistent with EPA Region 1's BMP Performance Extrapolation Tool or other BMP performance evaluation tool provided by EPA Region 1, where available.
iii. 
Stormwater management systems on redevelopment sites may utilize offsite mitigation within the same USGS HUC10 as the redevelopment site to meet the equivalent retention or pollutant removal requirements as described in the Massachusetts 2016 MS4 Permit part 2.3.6.a.ii.4(b).
iv. 
Redevelopment activities that are exclusively limited to maintenance and improvement of existing roadways, (including widening less than a single lane, adding shoulders, correcting substandard intersections, improving existing drainage systems, and repaving projects) shall improve existing conditions where feasible.
Roadway widening or improvements that increase the amount of impervious area on the redevelopment site by greater than or equal to a single lane width shall meet the requirements fully.
5. 
As-built drawings shall be submitted no later than two years after completion of construction projects and must depict all on-site stormwater controls (both structural and non-structural) designed to manage the post-construction stormwater associated with the site. The submittal shall include planned long-term operation and maintenance practices that will be undertaken to ensure adequate on-going functioning of site controls.
a. 
Erosion. Erosion control provisions shall be designed and executed to prevent erosion or excessive uncontrolled surface water runoff from draining onto any public way, both during and after construction. No grading or clearing of land shall begin until all required erosion control measures are in place and fully constructed. Permanent erosion control measures including but not limited to re-vegetation, retention basins and siltation barriers may be required to ensure stormwater will not discharge onto the public way.
b. 
Sediment control. The Town may require measures to reduce tracking of sediment from construction vehicles onto the public way. The contractor is required to clean up any sediment inadvertently discharged, through tracking or other means, into the public way or drainage systems. In no case shall sediment be allowed to discharge onto a public way or into public drainage infrastructure.
[Added 5-13-2019 ATM by Art. 47[1]]
This section is applicable to any construction activities or land alteration resulting in total earth disturbance equal to or greater than one (1) acre (or activities that are part of a larger common plan of development disturbing greater than one (1) acre).
a. 
In addition to complying with· § 88-4, Erosion and sediment control requirements, controls must be in place to ensure proper handling and disposal of demolition debris, litter, concrete truck wash out, chemicals and sanitary wastes to prevent these wastes from being discharged into the public stormwater system or waters of the commonwealth.
b. 
Construction site operators performing land disturbing activities must implement a sediment and erosion control program that includes best management practices (BMPs) as appropriate for the conditions at the site. The BMPs shall meet the design standards as detailed in the Massachusetts Stormwater Handbook, as amended.
c. 
The Town has the right to inspect construction sites and enforce compliance with approved stormwater management plans and construction permits.
[1]
Editor's Note: This article also renumbered former § 88-5, Fines and penalties, as § 88-6.
Any person violating this chapter shall be punished by a fine of not more than two hundred dollars ($200.) for each offense, and may have his permit revoked. Each day that such offense continues shall constitute a separate offense.