How Stormwater and Debris Separators Help To Keep The Streams and Rivers Clean
Stormwater that has been contaminated as it flows along streets, off roofs, and from parking lots is a major source of pollution in nearby creeks. The storm drains that are located at the street level collect water that has flowed onto the street from industrial sites, urban centers, farmland and residential properties. This water carries with it oils, greases, litter, garbage, pesticides, silt, heavy metals, and an unlimited number of other waste products. It is imperative to sort out as much of the debris and contaminants long before the water reaches the local streams and rivers. There are a number of types of stormwater and debris separators that are used along the way to help purify the water. Here are just a few.
The First Line of Defense Is The Storm Grate
Keeping large plastic bags, food containers, tree branches and other debris from entering the stormwater system at all is the first step. These extra large items can serve to clog up the system and prevent good flow when the hard rains hit. So it’s best in most cases to catch them right at the entrance with the proper grate. Then the street cleaners, whether manual or machine, can clean the grates regularly to prevent the entrance of these contaminants.
Even before that, some businesses will be forced to install catch basins that will prevent most of their runoff from entering the street. Some industrial locations are even forced to cover areas so that rainfall won’t leach heavy metals from the soil and carry it into the street. These are all preventative measures that need to be taken on a site by site basis after careful inspection and consideration.
After The Stormwater Enters The System
Then, almost immediately there are debris separators called hydrodynamic separators that will remove up to 80% of the remaining contaminants. They do this without moving parts, taking advantage of gravity and water’s natural swirling properties.
Floating debris, like litter, plastics, oils, and greases, are usually eliminated to an underground retention tank by the swirling action. Then, heavier debris and silt is allowed to settle to the bottom where it accumulates as well. These hydrodynamic separators come in many sizes to fit the amount of runoff, types of debris, and restrictions of space due to bedrock or utilities underground.
Each large separator will have clean-out manhole covers that can easily be accessed by large vac trucks that make regular rounds on dry days. The debris can then be extracted and processed either by pyrolysis or dumping in a landfill.
After The First Line Of Defense
There are several other types of stormwater and debris separators that can be installed inline or at a stormwater collection basin. These can continue to separate out silt, organic debris, and chemicals until the water is sufficiently clean to enter a local creek without causing a shock to the local wildlife.
When it comes to keeping the streams and rivers clean the most important place to start is at the source of the contaminants. Then all along the way, each type of contaminant is removed before it gets to the final stage. This is by far the preferable way to handle storm water. It takes hard work and diligence but pays off with clean water in the streams with plenty of natural wildlife.