Storm water management’s history started in the 80s when the EPA did a Nationwide Urban run-off Program (NURP) study. This study was to evaluate the extent of the effects of urban run-off on water quality problems, and also to evaluate how to control urban run-off. The recommendation that resulted from the NURP study was that urban run-off should be added to the list of environmental issues that require control in order to protect water quality.
The damage associated with elevated urban flow, flooding, erosion, and aquatic habitat destruction were fairly easy to deduct and then control. Toxicity levels required extensive collection and documentation of water samples during storms. The NURP study increased evidence of high pollutant levels found in urban run-off.
The NURP study was able to identify ‘point sources’ as the main contamination source of storm water pollution in the nation’s water bodies. Point source is identified by the EPA as “any single identifiable source of pollution from which pollutants are discharged, such as a pipe, ditch, ship or factory smokestack.”
Commonplace point sources include industrial buildings such as factories, sewerage facilities, oil refineries, mills, chemical handling facilities, automobile manufacturers, etc. These types of business usually discharge at least one pollutant from their facilities into water bodies. Large farms, like concentrated animal feeding operations (CAFOs), can also pose a risk if untreated animal waste enters water bodies as raw sewerage. The effects of unregulated discharge from point sources can be water pollution resulting in unsafe swimming and wildlife harm, and unsafe drinking water. While some chemicals released are harmless, others are toxic to both wildlife and humans. A chemical can be harmful dependent on various factors; type of chemical, concentration, release timing, weather conditions, and local organisms.
In order to control point source discharges, the Clean Water Act established the National Pollutant discharge Elimination System (NPDS) in 1987. Under the NPDES program, point sources must acquire a permit from the state and EPA before discharging into any body of water. The point source must treat its discharge to reduce the level of pollutants. More stringent controls can be placed on a point source to protect a specific body of water.
In 2014, a new Industrial General Permit (IGP) was adopted, under which even facilities that do not have exposure to storm water must obtain a No Exposure Certificate (NEC) from the State Water Resources Control Board (SWRCB). NECs state that industrial activities will not be exposed to rain water, and, that contaminants will not be picked up by storm water run-off which will discharge off-site, and includes previously excluded ‘light industry’. The IGP allows the SWRCB to enforce requirements for industries to adopt plans, practices, storm water testing, spill clean-ups, and reporting schedules that demonstrate the industry is operating in ways that safeguard water quality.