What is Water Contamination?

Safe Drinking Water Act – The Safe Drinking Water Act (SDWA), passed by Congress in 1974, authorized the United States Environmental Protection Agency (EPA) to establish minimum standards to protect tap water. SDWA defines “contaminant” broadly, to include any physical, chemical, biological or radiological substance or matter in water. Drinking water often contains small amounts of some contaminants. Some drinking water contaminants may be harmful at certain levels, but the presence of contaminants does not necessarily indicate a health risk. Germs that commonly include tap water, according to the U.S. Center for Disease Control and Prevention (CDC), include:

• Cryptosporidium (Crypto)
• Campylobacter
• E. coli O157
• Enterovirus
• Giardia
• Hepatitis A virus
• Legionella
• Norovirus
• Rotavirus
• Salmonella
• Shigella

Chemical contamination can occur naturally. Some rocks and soil naturally contain chemicals and minerals such as arsenic, copper, lead, nitrate, radon and uranium. Other common chemical contaminants include nitrogen, bleach, salts, pesticides, metals, toxins produced by bacteria, and human or animal drugs. 

How does contamination happen?

The CDC lists common ways that harmful germs and chemicals can get in the water:

• Fertilizers, pesticides and other chemicals from nearby land
• Feeding operations from industrial animal farms
• Manufacturing
• Overflowing sewers
• Storm water
• Wildlife
• Distribution system problems, including cracks in pipes

Who regulates water contamination?

Who regulates water?   The SDWA gave the EPA authority to establish minimum standards to protect tap water. The SDWA was amended in 1986 and 1996 requiring a variety of specific actions to protect drinking water and its sources including rivers, lakes, reservoirs, springs, and ground water wells. Thewas amended in 1986 and 1996 requiring a variety of specific actions to protect drinking water and its sources including rivers, lakes, reservoirs, springs, and ground water wells. The EPA currently sets legal limits on over 90 water contaminants. EPA also sets water-testing schedules and methods for water systems. The EPA’s Contaminant Candidate List (CCL). is a list of contaminants that are known or anticipated to occur in public water systems but are not subject to any regulation. SDWA requires the EPA to publish the CCL every five years. After a final CCL is published, EPA conducts Regulatory Determinations, using SDWA criteria, to determine whether the contaminant should be regulated:

• Does it have an adverse human health effect?
• Is it known or likely to occur in public water systems with a frequency and at levels of public health concern?
• Will regulation present “a meaningful opportunity for health risk reductions for persons served by public water systems?”

SDWA authorizes the EPA to oversee the states, localities and water suppliers who implement its standards. SDWA also gives individual states the opportunity to set and enforce their own drinking water standards, as long as the local standards are as least as stringent as EPA’s national standards. New York, for example, has a Drinking Water Source Protection Program to help communities implement protection programs through water use regulations. New Jersey has its own version of the SDWA.