How Stormwater Filters Clean The Effluent Many Times Through The System
As with most things in life, prevention is far better than trying to fix things at a later date. In stormwater treatment that statement is true in every sense because stopping the pollutants at their source is many times better than cleaning them up at the end. In addition to that, filtering the stormwater all along the way for various contaminants, pollutants, and debris is the preferred way to end up with clean water for disposal into creeks and rivers. In order to do the best job, it’s important to analyze the water at various intervals and install stormwater filters in addition to preventative measures. That will require people walking through the entire watershed and making assessments of what is in the runoff, where it comes from, and how to intervene to limit the amounts of contaminants.
After The Prevention Measures Are Implemented
Prevention will entail going to every storm drain and examining the contents, then taking a look around to find the source. It may be a fast food restaurant, an industrial site, a large parking lot, a home, or any one of thousands of sources. Some can be eliminated while others can only be mitigated, but that’s where to start.
The contents of the storm water at each drain have to be analyzed for all types of contaminants that still remain after prevention measures. Then special stormwater filters can be installed to separate out various pollutants like litter, cigarette butts, oils, heavy metals, sand or silt. The first filter is always a storm drain grate that is the right shape and size to capture the garbage that presents itself most often.
Stormwater Separators Are The Next Step
Once the rain runoff has passed into the system below the storm drain it can then be filtered in many ways. There are hydrodynamic separators to separate solids from floatables in the runoff, this is a major step. After that, there are at least another dozen types of filters each with a special function of removing oils, pesticides, fertilizers, silt, sand, rocks, leaves, or any other type of problem. Most are 80% to 90% effective in removal of their target pollutant.
Most of the time the pollutants are diverted into separate underground retention chambers that will allow clear water to siphon off of the top while still holding the pollutants. Then, on a regular schedule, vacuum trucks will come by and quickly remove the manhole cover and vacuum out the contents for further processing.
There Are Also Special Stormwater Filters for Special Pollutants
Many times in industrial areas, near busy highways, or near landfills and wrecking yards there hare high concentrations of a certain pollutant. In those cases, there are special filters that can be added to the storm drains to either skim off oils, or filter out pesticides on the spot. These have to be changed frequently but do offer an excellent solution to the problem of many chemicals that are hard to filter out in the final settling pond before the water enters the local stream.
The job of stormwater management is more important than ever with the streams and rivers clogged with debris, chemicals, and other pollutants already. The planet can’t afford another 100 years of dumping wastes into the oceans either. Getting to the source and then filtering the runoff water every step of the way is the only solution that works.