[HISTORY: Adopted by the Town Council of the Town of Merrimack 7-21-2011; amended in its entirety 12-7-2017. Subsequent amendments noted where applicable.]
The purpose of this chapter is to protect water quality in the Town of Merrimack (Town).
As used in this chapter, the following terms shall have the meanings indicated:
- BEST MANAGEMENT PRACTICE (BMP)
- As set forth in the New Hampshire Stormwater Manual, a proven or accepted structural, nonstructural or vegetative measure which reduces the quantity or improves the quality of stormwater runoff.
- Any construction, land altering or grading activities, other than for agricultural practices.
- ENVIRONMENTAL PROTECTION AGENCY (EPA)
- Federal agency responsible for implementing the Clean Water Act.
- Detachment or movement of soil or rock fragments by water, wind or ice.
- NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM (NPDES)
- The water quality program, as part of the Clean Water Act, implemented by the EPA to control the discharge of pollutants into surface waters of the United States.
- NEW HAMPSHIRE STORMWATER MANUAL
- Reference guide prepared by the New Hampshire Department of Environmental Services to manage stormwater, which, unless expressly exempted by the Town, shall include any and all amendments adopted subsequent to the enactment of these standards.
- PROJECT AREA
- Disturbed area plus any area with associated off-site improvements.
- RESPONSIBLE PARTY
- Entity responsible for submitting a SWMP such as the owner, developer, applicant or owner's legally designated representative.
- Water that is not absorbed, evaporated or otherwise stored within the contributing drainage area.
- Mineral or organic matter transported or deposited by water or air.
- STORMWATER MANAGEMENT PLAN (SWMP)
- A plan, required by the Town, which manages stormwater runoff through site design, pollutant source controls, structural BMPs and construction phase practices.
Prior to disturbance, the responsible party shall submit a SWMP to the Community Development Department (CDD) for any tract(s) of land that results in a total disturbance of 20,000 or more square feet of land.
Construction stormwater management.
Design standards. Design of erosion and sediment control BMPs shall be in accordance with, at a minimum, the design guidance set forth in the New Hampshire Stormwater Manual, which are hereby incorporated by reference.
Pre-construction meeting. Responsible party and its engineer or technical representative shall attend a mandatory pre-construction meeting with the CDD and the Department of Public Works (DPW) at least two weeks prior to commencement of disturbance. Two copies of the SWMP shall be provided at that time. All documents shall bear the seal and signature of a New Hampshire registered professional engineer (PE).
Responsibility. The responsible party shall install, inspect, report, operate and maintain all stormwater management and erosion control measures required by these standards.
Bonding. A bond or other security shall be provided in an amount, with surety conditions satisfactory to CDD and DPW, for construction and installation of control measures.
Site development commencement. Development shall not commence before the SWMP receives approval from CDD and DPW and BMPs are installed in accordance with the approved SWMP.
Reporting. A log and report must be submitted to CDD each week and within 24 hours of any storm event with greater than 0.5 inches of rainfall. Reports shall detail all inspections, actions taken per the SWMP, dates of action and follow-up action required.
Post-construction stormwater management.
Design standards. Design of post-construction stormwater management shall be in accordance with, at a minimum, the design guidance set forth in the New Hampshire Stormwater Manual, which are hereby incorporated by reference.
Post-construction meeting. The responsible party and its engineer or technical representative shall attend a post-construction meeting with CDD and DPW.
Responsibility. The responsible party shall install, inspect, report, operate and maintain any post-construction stormwater management and erosion control measures.
Bond release requirements.
Ongoing inspection and operational maintenance requirements for water quality measures required by the SWMP shall be a condition of site plan approval or, in the case of other development not subject to site plan approval, included as a covenant in the underlying deed(s).
Attendance by the responsible party at a post-construction meeting.
As-built plans bearing the seal and signature of a New Hampshire registered PE.
Approval of the bond release by both CDD and DPW.
Reporting. Each SWMP shall require annual site inspections by the responsible party that shall be documented and, at a minimum, include review of stormwater flow paths, accumulation of any sediment, condition of contaminant control devices, stormwater quality observations, corrective actions and time frames. All records of the inspections shall be submitted to CDD.
The purpose of this section is to enact locally, administrative and enforcement procedures set forth in RSA Title LXIV, specifically RSA 676:15, 17, 17-a and 17-b, and to authorize penalties and remedies for enforcement of the provisions of these standards. Any violation of these standards shall be subject to enforcement by either the Code Enforcement Officer or the Planning and Zoning Administrator or their designated agent.
Nothing contained herein, or any SWMP granted pursuant hereto, shall be construed to exempt any responsible party from complying with all applicable state or federal laws/regulations. In the event of conflicting requirements, the stricter standard shall apply.
A waiver of these standards, in whole or in part, may be granted when the strict application of these standards would impose unnecessary hardship because of the unique characteristics of the land including, but not limited to, the size, character, location, nature of use, or other unspecified conditions of the project area. Waivers shall only be granted with approval of both CDD and DPW.
All construction contemplated by the SWMP shall be completed within a period of four years from the date of approval.