The Storm Water System and the Sewer System

The Differences Between the Storm Water System and the Sewer System

The storm water system and the sewer system have a lot in common. They are both pipe systems and they both convey liquid from one place to another. However, that's about as far as the similarities go.

Many people don't even realize there is a difference. As we drive around on our way to work or to the grocery store, we see the storm water system. The inlets in the gutters are what we notice, but how many of us have taken notice of exactly what these are? A lot of cities these days paint slogans like 'no dumping, drains to lake' or 'caution: drains to creek' right above the storm water inlet. This is to notify or remind people to be careful what they are discharging into the drains.

The main function of the storm water drainage system is to keep storm water from flooding the streets, businesses and homes, however, it also picks up any pollutants that might be lying around. This includes paper, empty food or beverage containers, pet waste, oils, pesticides, cigarette butts or anything else that doesn't belong on the streets or in the gutters. Since the storm water system does not go to a treatment plant, whatever is washed into the system is carried along to the discharge point. The discharge is the nearest stream, creek, lake or even the ocean. Therefore, pollution is a major environmental hazard in the storm water system.

Now, the sewer system is very different in that it is not designed to drain the streets of flood waters, unless the storm water system is flooded, then the extra water will sometimes wash into the sewers. But, the sewer system's main function is to convey waste water from homes and businesses directly to a waste water treatment plant where the waste is strained, clarified and disinfected before being discharged into a lake, pond or creek. Even though the treatment plant cleans and filters the water, unless it receives a series of disinfecting procedures, it's generally not fit for drinking. There are also some pollutants that cannot be effectively removed from the waste stream. Heavy metals are very difficult, if not impossible, to remove.