The City of Nashua is doing its part to manage stormwater. However, everyone living and working in Nashua 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.  

Construction activities that disturb one or more acres; Or smaller sites disturbing less than one acre that are part of development or sale are regulated under the NPDES stormwater permitting program. Nashua's Stormwater Regulations have requirements for developers and site operators designed to protect water quality.

Prior to the start of construction, operators must obtain coverage under a  National Pollutant Discharge Elimination System (NPDES) permit, administered by EPA under the Construction General Permit (CGP). 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.

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

• EPA NPDES MS4 Information
• NH Soak up the Rain
• NHDES Guidance For Estimating Pre- And Post-Development Storm water Pollutant Loads
• UNH Stormwater Center Guidance For Stormwater Designs 
• EPA Stormwater BMP Pollutant Removal Tools and Information