The National Water Quality Inventory Report to Congress provides a general assessment of water quality based on biennial reports submitted under the Clean Water Act. The report states that approximately 30 percent of identified cases of water quality impairment reported in the United States are attributable to stormwater discharges.
When there is a storm event or snowmelt, stormwater runoff can flow directly into lakes, streams, rivers and oceans, affecting water quality. In developed areas, runoff enters a storm drain or sewer system, and then seeps into the environment. Again, water quality can be harmed with pesticides, fertilizers and many other man-made chemicals and pollutants that can be harmful to animals and vegetation. Industrial activity also is a source of runoff that demands stormwater sampling. Collecting a stormwater sample is called for.
Regarding stormwater samples, per the State of Washington Department of Ecology, “Stormwater management activities include keeping rainwater clean and using best management practices at sites or regional facilities to treat or infiltrate water before it's discharged. Stormwater monitoring and tracking stormwater quality helps us understand how well these activities by permittees and/or best management practices are working.”
In 1972, the U.S. Congress created the National Pollutant Discharge Elimination System (NPDES) as part of the Water Pollution Contract Act. The Act set a target date for the elimination of pollutant discharges, but by 1985, it became evident that the early focus on “point source” discharges (i.e., industrial activity and municipal wastewater treatment facilities) simply wasn’t comprehensive enough to fully address the problem.
Two years later, the NPDES program was expanded to include “non-point source” discharges – stormwater runoff from many varied sites (i.e., construction sites, croplands, and urban areas), as it was now understood that such runoff was a major contributor to the pollution of our surface waters. The collection of stormwater samples was an increasing need.
Today, U.S. federal and state laws covering virtually all lakes, rivers, and streams (as well as the oceans themselves), are in place to reduce pollution from stormwater runoff. To operate, those industries and municipalities affected by such regulations must comply with ever-increasing demands for stormwater
runoff control and stormwater sample reporting. Complete details of federal stormwater monitoring rules, regulations and practices can be found on the U.S. Environmental Protection Agency website.
The stormwater program includes Industrial Run-off, Construction site Run-off, Municipal Run-off, nd TMDL (Total Maximum Daily Load).
The EPA’s NPDES Storm Water Sampling Guidance Document explains that, “Data that characterize storm water discharges are valuable to permitting authorities and permittees for several reasons. First, stormwater sampling provides a means for evaluating the environmental risk of the storm water discharge by identifying the types and amounts of pollutants present. Evaluating these data helps to determine the relative potential for the stormwater discharge to contribute to water quality impacts or water quality standard violations. And, stormwater sampling data can be used to identify potential sources of pollutants. These sources can then be either eliminated or controlled more specifically by the permit.”