Stormwater runoff is unfiltered water that reaches streams, lakes, and oceans by means of flowing across impervious surfaces such as roads, parking lots, drive ways, and roofs. Naturally, rain water would dissolve into the ground, however this process is destroyed when buildings, roads, and parking lots cover the ground. Instead, rain runs into storm drains and streams, without being filtered, often picking up pollutants along the way.
Monitoring of fresh water sites in California conducted between 2001 and 2010 found that over 50 percent of collection sites showed some degree of toxicity or pollution harmful to fish or other aquatic life. It wasn’t until 1990, in response to the Clean Water Act of 1987, that the federal government began requiring effective storm water controls on development, in an effort to cut back on pollutants.
Catch basins and curb inlets often provide the first opportunity to trap pollutants from stormwater runoff, making them a popular choice among commercial developers for stormwater management. According to a University of California study, catch filters, or catch basin inserts, were able to remove 81.6 percent of lead and 54.3 percent of copper out of the water that passed through them.
Other solutions for stormwater runoff or stormwater pollution include a drop inlet spillway, which is a mechanical system that lowers water through a box or pipe structure, keeping it from coming into contact with impervious surfaces.
Finally, to reduce storm drainage, retain natural ground cover whenever possible in order to cut down on polluted stormwater drainage. Stabilize areas of bare soil with vegetation as soon as possible after grading, and plant more trees and shrubs. They capture and hold a lot of rain before it reaches the ground. Wherever possible, keep existing trees and bushes and plant more.
Whatever you choose to do to help with stormwater runoff, stormwater treatment is a step toward pollution management, and greener practices. Whether it is to plant more trees, or to use a catch basin, any bit of effort helps.