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Stormwater Resources for Site Development & Construction Activities

The City of Manchester is doing its part to manage stormwater. However, everyone living and working in Manchester can help manage stormwater and prevent water pollution, including developers and construction site managers/operators. Stormwater discharges from construction activities can contribute to larger pollutant loads that can have a detrimental impact on water quality if proper stormwater management practices and techniques are not employed.  

Manchester’s regulations have requirements for developers and construction site managers/operators designed to protect water quality. In the City of Manchester, subdivision and site plan review projects and construction activities that disturb >0.5 acres or >1,000 square feet of land with a 15% or greater slope must meet the requirements of the Stormwater Ordinance and Regulations and DPW Standard Specifications.

Permit Requirements for Construction Activities

Construction General Permit (CGP) Requirements: For construction sites that disturb one acre or more, operators must obtain coverage under a National Pollutant Discharge Elimination System (NPDES) permit, administered by EPA under the Construction General Permit (CGP) prior to the start of construction. The CGP requires operators of construction sites to meet effluent limits and requires operators to develop a Stormwater Pollution Prevention Plan (SWPPP) detailing the erosion and sediment controls and pollution prevention measures that will be implemented to meet the requirements of the CGP.

City of Manchester’s Site Plan and Subdivision Applications: For construction sites that meet the requirements of the City of Manchester’s Subdivision and Site Plan Review Regulations, a Site Plan application and checklist or Subdivision application and checklist are required to be submitted to the Planning Board. Projects must also meet the requirements of the Stormwater Ordinance and Regulations and Standard Specifications and include a completed Stormwater Management Checklist for Planning Projects if they wish to be exempt from a separate application filing under the Stormwater Ordinance.

City of Manchester’s Land Disturbance Permit: For construction sites that do not require a Site Plan or Subdivision application and disturb >0.5 acres or >1,000 square feet of land with a 15% or greater slope, operators must submit a Land Disturbance Permit Application form and checklist to DPW-EPD for permitting and demonstrate compliance with the City of Manchester’s Stormwater Ordinance and Regulations and Standard Specifications. 

Other Regulations – Sewer: New development or redevelopment projects must also comply the City of Manchester’s Code of Ordinances, Chapter 52: Sewers. New or modified sewer connections shall be clearly depicted on site plans, with support data/calculations provided for increases in flow to confirm that the existing municipal sewer system  and the existing service connection are able to handle both estimated peak and daily average sewer flow increases. Projects that propose new discharges of industrial wastewaters into a City sewer also require special permitting through the City’s Industrial Pre-treatment Program outlined in Chapter 52: Sewers. 

Best Practices at Construction Sites
The following practices will help reduce the volume of stormwater created and help prevent pollutants from coming in contact with stormwater. Click this link to learn more!

  • Reduce the amount of runoff from development. Maintain existing vegetation where possible, install perimeter controls such as hay bales and silt fences, and reduce the total amount of impervious cover on your site.
  • Encourage infiltration by installing infiltration-based features such as infiltration basins, subsurface infiltration, rain gardens, and bio-swales.
  • Only rain down the drain. Protect all storm drain inlets and streams located on your construction site or property.
  • Limit access to and from the site and stabilize construction entrances and exits.
  • Sweep frequently.
  • Protect stockpiles by storing under a roof, impermeable tarp, or plastic sheeting. Do not store or stockpile materials near a storm drain, wetland, or stream.
  • Perform major maintenance and repair of vehicles off-site.
  • Wash out concrete mixers only in designated washout areas away from resources, and set up small mixers on tarps.
  • Designate waste disposal areas. Remove trash, debris, and wastes on a regular basis and ensure that dumpsters are covered.
  • Clean up small spills immediately using dry cleanup methods.
  • Manage winter salt application and storage. Cover salt piles. Limit the amount of salt applied. Sweep and properly dispose of any visible salt deposits once the application surface or storage area has dried.


Resources for Developers and Construction Site Operators

If you have any stormwater-related issues or questions, please contact the EPD Stormwater Department at (603) 621-7735 or email us by clicking on the link below and selecting Stormwater from the subject drop-down: 
Email the Stormwater Department