A. 
Applicability.
(1) 
Except as expressly provided herein, stormwater runoff from ALL industrial, commercial, institutional, office, residential and transportation projects including site preparation, construction and redevelopment, and all point source stormwater discharges from said projects shall be managed according to the Stormwater Management Standards, as defined by the Massachusetts Department of Environmental Protection in the Stormwater Management Handbook, including, but not limited to:
(a) 
All housing development projects comprising three or more detached single-family dwellings;
(b) 
Housing development and redevelopment projects comprised of one or two detached single-family dwellings that have a stormwater discharge that may potentially affect a critical area;
(c) 
Construction or expansion of any parking lot where the total number of spaces is 10 or more; and,
(d) 
Any application required to comply with the Stormwater Management Standards by the Town of Easton' Wetland Protection Bylaw.
(2) 
The Stormwater Management Standards shall not apply to:
(a) 
Housing development and redevelopment projects comprised of detached single-family dwellings on one or two lots, provided that there are no stormwater discharges that may potentially affect a critical area;
(b) 
Multi-family housing development and redevelopment projects with four or fewer units, including condominiums, cooperatives, apartment buildings and townhouses, provided that there are no stormwater discharges that may potentially affect a critical area;
(c) 
Emergency repairs to roads or their drainage systems;
(d) 
Applications for Site Plan Approval where no new impervious surface is to be added provided that there are no stormwater discharges that may potentially affect a critical area;
(e) 
Applications for Site Plan Approval that result in fewer than 10 parking spaces; nor
(f) 
Applications for a Special Permit for a Common Driveway or Estate Lot.
(3) 
For phased projects, the determination of whether the Stormwater Management Standards apply is made on the entire project as a whole including all phases. When proposing a development project subject to the Stormwater Management Standards, proponents shall consider environmentally sensitive site design that incorporates low impact development techniques in addition to stormwater best management practices.
A. 
To the extent that it is feasible and in compliance with the Massachusetts Stormwater Management Policy, stormwater management shall incorporate Low Impact Development strategies. Low Impact Development (LID) is a stormwater management strategy concerned with maintaining or restoring the natural hydrologic functions of a site to achieve natural resource protection objectives and fulfill environmental regulatory requirements.
B. 
LID employs a variety of natural and built features that:
(1) 
Reduce the rate of runoff,
(2) 
Filter out its pollutants, and
(3) 
Facilitate the infiltration of water into the ground.
C. 
Rather than collecting runoff in piped or channelized networks and controlling the flow downstream in a large stormwater management facility, LID takes a decentralized approach that disperses flows and manages runoff closer to where it originates, and incorporates a set of overall site design strategies as well as highly localized, small-scale, decentralized source control techniques such as, for example, rain gardens, roof run-off collection or infiltration system, and permeable paving.
(1) 
The use of Low Impact Development techniques throughout the site is encouraged.
(2) 
Detention and filtration systems shall be located onsite and shall have curvilinear sides, so as to appear a natural part of the landscape.
(3) 
Manmade embankments shall have maximum side slopes of three feet horizontal and one foot vertical, or retaining walls shall be employed.
(4) 
Landscaped erosion control techniques will be preferred to the use of visible riprap.
(5) 
Roads, driveways and parking areas shall be graded, surfaced with asphalt, concrete, or other suitable non-erosive material, and drained in a manner to prevent nuisance of standing water, erosion, or excessive water flow across abutting streets, ways, or parking areas or to abutting properties and wetland resource areas.
(6) 
Natural drainage courses shall be utilized insofar as possible.
(7) 
Curbing shall be required only as necessary to limit off pavement vehicle access or for pedestrian safety, unless other suitable materials are used.
(8) 
All stormwater LID features, detention, and filtration systems shall be designed to conform to the stormwater Management Policy of the Massachusetts Department of Environmental Protection.
(9) 
Impervious surface should be minimized.
Every project subject to the the requirements of this Section shall submit a Stormwater Management Report. This report should document the stormwater management system proposed and provide the Town and its consultants with the information necessary to adequately evaluate the design.
A. 
Report Format.
(1) 
The report shall be ordered such that there is a section labeled and referenced to correlate directly to each section of the Massachusetts Department of Environmental Protection Checklist for Stormwater Report. All sections and information listed below shall be included in the report, in the order listed. Each section should be clearly labeled and separated from the previous section.
(2) 
Other information that should be included in the report in the as appropriate and within the relevant section includes, but is by no means limited to: established groundwater elevation,
(3) 
The report shall be printed double-sided.
B. 
Report Sections.
(1) 
Title. This section will identify the project name, location (i.e. street address and map and lot #), applicant, and engineer
(2) 
Introduction. This should be a summary narrative that includes:
(a) 
A description of existing topography and landscape at the site
(b) 
Existing stormwater drainage patterns
(c) 
Existing soil conditions and times of concentrations
(d) 
Proposed topographic, landscape and soil changes
(e) 
Proposed treatment methods and resulting stormwater drainage patterns
(f) 
A summary, in table format, of pre- and post-development curve numbers, run-off rates and times of concentration.
(3) 
Stormwater Checklist and Certification. The completed Checklist for Stormwater Report is to be included in this section
(4) 
LID Measures.
(a) 
Narrative that provides a summary of how the design is environmentally sensitive and what LID measures are being proposed.
(b) 
Detailed description and relevant design information for each method proposed. Operations and Maintenance plans for each design element must also be included.
(5) 
Stormwater Management Standards 1-11. For each standard, the report should address in sufficient detail each item that is checked on the Checklist for Stormwater Report. At a minimum, the detail should include a summary of the supporting calculations. The full drainage analysis calculations should be provided in an addendum to the report.
(6) 
Operations and Maintenance Plan.
(a) 
Plan must address operations and maintenance of all the proposed stormwater management structures and elements, including erosion control methods, during and post-construction
(b) 
The Operations and Maintenance Plan should have a section for each BMP structure or element proposed and shall include the following detailed information:
[1] 
Schedule of maintenance for each BMP
[2] 
Description of maintenance required for each BMP to ensure proper function
[3] 
Party responsible for conducting maintenance
Note: Reports should not include any information that is not relevant to the particular project being proposed. For example, portions of the regulations should not be quoted within the report unless they provide meaningful relevance; items in the checklist which have not been checked as applying to the proposed project should not be included.
As a standard condition of subdivision approval, upon completion of the project, the applicant shall submit the following:
A. 
A letter from a registered professional engineer certifying the structures and elements as constructed will meet the standards as intended by the approved plan and detailing any deviations from the approved proposed plan and their potential effect. A statement the work is in "substantial compliance" with no detailing of the deviations shall not be accepted.
B. 
An "As-Built" plan signed and stamped by a registered professional engineer or land surveyor showing in detail the exact location of all structures or elements, elevations and the topography of the finished grades. The issuing authority will issue a letter certifying completion upon receipt and approval of the final reports and/or upon otherwise determining that all work of the permit has been satisfactorily completed in conformance with this chapter.
A. 
The ability of Stormwater Management structures and elements to achieve the intended results is fully dependent on the system functioning properly on a continuing basis. To ensure the structures and elements are operated and maintained according to plan, as a standard condition of subdivision approval, the applicant shall submit an annual report to the Board for review no later than January 31 of each year. This report shall correlate to the originally approved Operations and Maintenance plan and shall include:
(1) 
Reference to each structure or element comprising the overall stormwater management system
(2) 
Information on when and by whom maintenance has been conducted over the past year
(3) 
Observation of proper function
(4) 
Recommendation for modifications or repairs, if necessary
B. 
Failure to Submit Annual Report May Result in a Fine.
(1) 
Failure to provide the report by the date due may result in a fine of up to $100 per day over the day on which the report was due.
(2) 
Submission of this report shall be the responsible of the developer until ownership of the stormwater maintenance system is turned over either to a homeowners' association or the Town; thereafter, if it is owned by a homeowners' association the annual report will be the responsibility of the homeowners' association.