How to Prevent Stormwater Pollution: 7 Guaranteed Practices

Stormwater pollution is the contamination of natural water sources caused by the runoff of chemicals or sediment during rain or snowfall. 

While residential neighborhoods and land development are typical causes of stormwater pollution, the EPA has identified construction sites, in particular, as an area of concern in their fight to curb stormwater pollution. 

In response, many states now require construction managers to apply for NPDES (National Pollutant Discharge Elimination System​​) permits for any construction site with water discharge that enters public waterways. In addition, some states even require construction sites to acquire clean water and sewage permits before beginning work.

While regulatory compliance could be a nightmare, the larger concern for construction managers, will be best preserving their work zone and the surrounding ecological habitat.

Stormwater pollution and improper sediment/erosion control can be devastating for construction projects. Not only do improper BMPs pose a risk to your construction site and materials, but they could come with hefty fines that threaten to derail projects altogether. 

Fortunately, with the help of a proper stormwater management plan, active stormwater consulting, and some of these BMPs listed below, you can plan ahead and ensure adequate safety of all site materials and stormwater runoff. 

1. Erect Structures for Sediment Loss

Soil and sediment control is especially critical because it’s one of the areas of a construction zone most easily disturbed. Unfortunately, sediment is also one of the biggest pollutants found in stormwater runoff. 

Sediment disturbance doesn’t need to be filled with chemical fertilizers and pesticides to be dangerous. Natural runoff of the native topsoil can disturb surrounding water sources, like lakes and streams, leading to a total loss of plant and aquatic life in those areas. 

Fortunately, construction managers can take several strategies to control sediment loss. Some BMPs include:

  • Stockpiling native topsoil and covering them with a protective tarp
  • Installing a silt fence on graded lots to absorb topsoil runoff
  • Installing organic filter tubes on downward slopes to impede the flow of sediment runoff
  • Protecting stormwater inlets with secure materials, including an organic filter tube, gravel, or silt fencing
  • Stabilizing exits with gravel to prevent waste materials from leaving the site
  • Temporary stabilization of disturbed areas that are not currently active

Using these strategies, you can help slow the flow of sediment runoff, thus allowing nature to filtrate sediment runoff as it enters water sources. 

2. Stabilize Soil

The EPA’s General Construction Permit (GCP), along with numerous state permits, requires construction managers to preserve the native topsoil unless deemed “unfeasible.” One strategy they recommend is stockpiling topsoil to use later to stabilize native vegetation. 

Another strategy is stabilizing the topsoil through a bevy of strategies, including seeding, mulching, and erosion control blankets. 

For example, applying a uniform layer of mulch in high-traffic areas will help prevent soil disturbance and encourage vegetation regrowth after construction. 

An erosion control blanket is also a temporary measure to stabilize soil and promote the regrowth of the vegetation afterward. Erosion control blankets consist of a woven blanket of organic materials that help feed soil nutrients and protect them against disruption. 

As a final note, plan for soil stabilization once construction projects have ended or if construction zones will be inactive for as many as 14 days. 

3. Manage Vegetation

Fortunately, you could save a lot of money on these temporary sediment controls by implementing strategies to preserve the native vegetation surrounding construction zones. 

However, where not possible, placing temporary vegetation on slopes, grass sod around inlets, and erecting rain gardens on site will help filter out any stormwater and sediment runoff from your construction site.

Once construction has ceased, be sure to reseed and restore all disturbed vegetation to return the ecological habitat to its previous form. 

4. Dispose of Waste Properly

Sediment runoff is not the only source of pollution from a construction zone. Workzone materials and hazards could be even more devastating sources of pollution if not properly controlled.

Train and educate all workers in proper waste disposal management. Provide onsite containers marked off for waste disposal. Be sure to inspect sites daily to collect any remaining debris after the workday and properly dispose of materials. 

Finally, you should set up BMPs for overlooked things like toilets, which should be located off construction sites, far away from any natural water sources, and out of the path of stormwater runoff. Identify all potentially hazardous sources and implement proper BMPs to eliminate the risk of any potential runoff or leaching of hazardous chemicals. 

5. Cover Up Construction Materials

All construction materials, including hardware, mechanical equipment, and machinery, should be covered up when not in use to prevent chemical runoff during storms or off days. Reserve an area of your construction zone to store all materials and equipment, and cover them with a protective tarp. 

As a bonus tip, minimize trips on and off-site to prevent runoff from exits and help keep an accurate inventory of all materials to prevent run-off or pollution. 

6. Hazardous Washout

Common construction materials like stucco, concrete and paint have the potential to cause devastating environmental damage if they are not properly disposed of or contained after a washout. For example, concrete washout has the potential to kill all surrounding wildlife it comes in contact with and will even cause burns and skin irritation to anyone who comes in contact with it. 

To eliminate the risk of washout pollution, place-specific washout areas on your site to eliminate runoff from concrete chutes being washed as they enter the site. In addition, you should also handle all stucco and paint that enters the site in a washout area. 

While temporary barriers will help prevent liquids that slosh around after washouts, we often recommend creating washout basins to properly contain any washout liquids to eliminate the risk of runoff entirely. Furthermore, use as little liquid as possible to wash equipment and chutes to reduce the risk of washout pollution. 

Storing and disposing of washout materials in a leakproof container will eliminate almost any risk of pollution from washout. 

Finally, never dump washout material in a storm drain, and be sure to recycle washout materials at a qualified recycling plant or waste disposal site. 

7. Plan Ahead with Your SWPPP

Finally, the best way to minimize ecological disturbance through stormwater runoff is to plan ahead and educate workers on proper BMPs. 

Work with an environmental consultant to create an SWPPP to erect proper BMPs that address each area we’ve covered above. 

A proper SWPPP plan will identify sources of pollution, prescribe control measures to reduce pollution, and ensure compliance with local and federal regulations to prevent fines. 

Stormwater runoff and pollution are major areas of concern that all construction managers must take seriously. Not only does stormwater pollution leave your business susceptible to fines, but it could ruin your reputation and cause extensive damage to the surrounding area that takes years to recover. 

Fortunately, with these BMPs, you’ll be better prepared to prevent stormwater and sediment runoff before it occurs. For help constructing an SWPPP or navigating environmental permits and regulations, be sure to work with a qualified environmental consultant. 

Consultants are trained in proper BMPs and regulatory compliance and can help you create an SWPPP that leaves your site squeaky clean.