Construction Sites and Stormwater
Construction Sites and Stormwater
When stormwater drains off a construction site, it carries sediment and other pollutants that can harm lakes, streams, and wetlands. The U.S. Environmental Protection Agency estimates that 20 to 150 tons of soil per acre are lost every year to stormwater runoff from construction sites.
To protect Minnesota waters, the MS4 permit required by the Minnesota Pollution Control Agency (MPCA), sets regulations for construction site owners and operators to prevent stormwater pollution during and after construction. As part of the City’s building permit application, site owners/operators must create a stormwater pollution prevention plan that explains how they will control stormwater. This plan must also be reviewed and approved by our Stormwater Inspector (Residential) or our City Engineers (Commercial).
Current Stormwater Challenges in Construction
The top five construction stormwater permit violations:
Missing or inadequate soil stabilization — Mats, mulches, blankets, and other strategies keep disturbed soils in place during construction.
Missing silt fence or other perimeter controls — Perimeter controls such as silt fence and biorolls prevent runoff and allow water through while sediment settles out.
Missing or inadequate inlet protection — Inlet protection captures sediment before it enters storm sewers.
Vehicle tracking — Vehicles driving off the site can track sediment onto paved surfaces. Rock pads/driveways and similar practices knock dirt off tires before it can be carried off the construction site.
Stormwater protection practices not maintained — For instance, it's not enough to just install a silt fence. It must be checked to ensure it hasn't been breached or knocked down.
Minnesota Pollution Control Agency. Construction stormwater. Retrieved from: https://www.pca.state.mn.us/business-with-us/construction-stormwater
*Please contact the City of St. Francis at 763-233-5200, if you see any of the above violations happening around construction areas.
