EPA Water Analysis

The U.S. Environmental Protection Agency (EPA) sets standards for water quality with respect to organic, inorganic and biological contamination. It also sets standards for turbidity and radioactive contamination. The EPA publishes sampling and analytical methods for each type of water contaminant analysis.

Primary and Secondary Standards

• The EPA has primary drinking water standards to protect against toxic substances from being in drinking water. These substances have been shown to have deleterious health effects such as birth defects or cancer. National Secondary Drinking Water Regulations prescribe maximum concentrations to avoid contaminants that may cause cosmetic effects (tooth or skin discoloration) or provide undesirable taste, odor or color. Secondary standards are un-enforceble guidelines that monitor aluminum, chloride, fluoride, iron, manganese, silver, sulfates and zinc. In addition, guidelines are suggested for limiting foaming agents, corrosiveness, color, odor, dissolved solids and pH.

Inorganic Contaminants

• Industrial products, byproducts and waste can contaminate water supplies.

  The EPA has primary standards for many inorganic contaminants. Inorganics are metals and minerals that come from natural sources as well as agriculture, industry and waste. Typical inorganics monitored by the EPA include asbestos, cadmium, chromium, copper, lead, mercury, selenium and thallium. Nitrates and nitrites are found in agricultural runoff and are also monitored. Other monitored inorganics include beryllium, barium and antimony. Acceptable levels are different for agricultural use and drinking water, and are measured in parts-per-million concentrations.

Organic Contaminants

• Agricultural runoff can contain organics such as pesticides.

  Organic (carbon compound) pollutants are mostly man-made chemicals that may leach into water supplies. The EPA tests for more than 40 different organics produced as pesticides, industrial byproducts and waste, petroleum byproducts and others. Organics are tested in the ranges of parts per million to parts per trillion. Potential organic contaminants are identified by regions where they are usually known to occur.

Biological Contaminants

• Improper sewage treatment can lead to bacterial contamination of water.

  Bacteria and virus levels are monitored to determine the effectiveness of treating water and identify possible contamination from sewage or other unclean sources of water. Species monitored include Giardia lamblia, legionella, and total coliform. In addition, turbidity (clarity) is monitored.

Radiological Contamination

• Radioactive waste often comes from natural sources.

  Radioactive contamination is monitored by alpha radiation emission and beta radiation emission. Combined radium 226/228 is also monitored. Radioactive contamination usually comes from natural deposits of radioactive materials.

Analytical Methods

• The EPA has specific guidelines for water analysis.

  The EPA has 10 publications outlining approved analytical methods for drinking water analysis and compliance. For more information on specific analyses, see Resources. In addition, the EPA outlines sampling methods including how to collect, preserve and store water samples.