Excavating and grading soil can cause sediment and other pollutants to flow into storm drains. The content in storm drains then flows directly into streams and the ocean.

Erosion control blankets cover bare soil and freshly graded surfaces. (Photo by Mike Hug)

Sediment is Dirty

Sediment is the most common pollutant washed from work sites into storm drains. Once in the water supply it can clog fish gills, block sunlight needed by marine life and increase the ocean’s water temperature. These consequences harm sea life and disturb the food chain upon which both fish and people depend.

Furthermore, poorly maintained vehicles or heavy construction equipment can leak fuel and oil. Sediment may soak up these chemicals, as well as other work-site pollutants such as pesticides, cleaning solvents, cement wash and asphalt which increases the potential harm from sediment runoff.

Act Preventively

SLAC personnel can employ simple measures to reduce the amount of sediment pollution.

• During construction, cover all excavated material with plastic or place it in a bin. If covering the piles is impractical, other protective measures can be used with the approval of the ES&H Construction Inspector (Ext. 4512).

• Protect the nearest catch basins with fiber rolls, berms or plastic to keep material from entering the storm drain system.

• During the rainy season, cover freshly graded surfaces with erosion control blankets to minimize erosion.

• Finally, clean the work site at the end of each day.

Be a Good Soil Steward

Once construction is complete, there are a few steps you can take to further ensure construction activities do not damage the environment.

• Inspect all catch basins in the area of the site and clean if necessary.

• Remove construction debris from the entire site at the end of the project.

• Cover bare soil with seed and erosion control blankets.

• Revegetate the site with fast-growing annual and perennial grasses to bind the soil and prevent erosion.