Business and Industry
The City's storm drain system conveys stormwater runoff from developed areas to local waterways to prevent flooding. This system includes publicly-owned storm drain inlets (which are the grated inlets commonly located in gutter flowlines adjacent to streets or in parking lots), and a network of underground piping and manholes, open channels, and roadside ditches. The City's storm drain system also includes publicly-owned streets, sidewalks and gutters. Stormwater flows from these surfaces into the storm drain system. Privately-owned drainage systems usually discharge to the City's storm drain system as well.
Sinks, toilets, and interior floor drains must be connected to the sanitary sewer system. The wastewater discharged to the sanitary sewer receives treatment to remove pollutants prior to release to creeks and rivers. Pollutants contained in stormwater runoff flow directly into local waterways, without treatment where they can be harmful to humans and the environment. Oil and grease, food waste, paint, concrete-related wastewater, chemicals and even dirt must be prevented from entering the storm drain system in order to preserve our local waterways.
Pollutants can also be washed into the storm drain system and local waterways by non-stormwater discharges such as irrigation runoff or in wastewater from hosing down or pressure washing polluted surfaces into the storm drain system.
BMPs are measures that reduce or eliminate pollutant discharges to the storm drain system. BMPs commonly fall into three categories:
All treatment control BMPs require regular inspection and maintenance to ensure proper operation.
BMPs should be considered and implemented in the above order: administrative, source control, and then treatment control. Implementing BMPs in this order is the most cost effective and does the best job of protecting stormwater quality. Administratively eliminating pollution sources will almost always be the best solution. Using source control BMPs to eliminate pollutant sources prior to polluting stormwater runoff should be your next option. Your last option is to treat stormwater runoff in an effort to remove pollutants. Treatment is likely the most expensive and often least effective way to go. Treatment control should be a part of your overall stormwater pollution prevention strategy as a last and final effort to remove pollutants that could not feasibly be addressed through administrative and source control BMPs. Treatment control BMPs should not be used as stand alone BMPs.
Pressure washing is an excellent way of removing pollutants from outdoor surfaces. However, pressure washing wastewater should never be discharged to a storm drain. Storm drains should be covered, or the path to the drain should be blocked during pressure washing. With the property owner's permission, the collected wastewater can then be pumped into a sanitary sewer clean out, or, in some instances, discharged to a landscaped area, provided that the discharge does not overflow the landscaped area, contain hazardous constituents, or create nuisance conditions. Sump pumps and wet/dry shop vacuums can be used to pump the wastewater.