It shouldn’t come as a surprise that soil exposed by construction activities is vulnerable to erosion. In fact, runoff from a construction site can result in the loss of 35–45 tons of sediment per acre each year. Even during a short period of time, construction sites can contribute more sediment to streams than would be deposited naturally over several decades. Excess sediment can cloud the water, reducing the amount of sunlight reaching aquatic plants; clog fish gills; smother aquatic habitat and spawning areas; and impede navigation in our waterways. (EPA) That’s why learning about stormwater pollution is so important.
What is Stormwater Runoff?
Stormwater runoff is rain or snowmelt that flows over land and does not sink into the soil. In small amounts, stormwater runoff occurs naturally from almost any type of land surface, especially during larger storm events.
Buildings, homes, roads, parking lots, sidewalks, and other surfaces that don’t absorb water can increase the volume and velocity of runoff, which causes erosion and flooding. This, in turn, can degrade the biological habitat of waterways.
Imagine a city street during a thunderstorm. As rainwater flows over asphalt, it washes away drops of oil that leaked from car engines, particles of tire rubber, dog waste, and trash. The runoff goes into a storm sewer and eventually ends up in a nearby river. This is stormwater pollution.
What can We do about Stormwater Pollution?
The Clean Water Act (CWA) was enacted in 1972 with the hope of restoring and maintaining clean, healthy waterways in the United States. It was a revision of an earlier law, the Federal Water Pollution Control Act of 1948. However, it is the Water Quality Act of 1987 that is the basis for current regulations.
Now, stormwater discharge permits are required for a number of activities, including those associated with industrial activities. Permits are also required for discharges from municipal separate sewer systems that serve a population of 100,000 or more.
In the construction industry, following the EPA’s regulations means applying for, receiving, and adhering to a Construction General Permit. This requires construction projects to develop a plan for limiting the amount of runoff that comes from the site. This is called a Stormwater Pollution Prevention Plan (or SWPPP for short).
What’s a SWPPP?
A SWPPP is a site-specific, written document that identifies potential sources of stormwater pollution. It also describes practices that will be put in place to control how much pollution is discharged from the site. Last, but far from least, it must identify the procedures that will be implemented to comply with the CGP. These controls are more commonly known as best management practices (BMPs). Which BMP is best? Well, that depends on the site!
We’ll discuss BMPs and their different uses next week (so be sure to check back). Until then, if you need training in stormwater pollution prevention (it’s required, y’all), visit us at hardhattraining.com.
Good luck and stay safe!