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Water: Basic Information about Regulated Drinking Water Contaminants

Basic Information about Polychlorinated Biphenyls (PCBs) in Drinking Water

Polychlorinated Biphenyls (PCBs) at a Glance

Maximum Contamlnant Level (MCL) = 0.0005 milligrams per Liter (mg/L) or 500 parts per trillion (ppt)

Maximum Contaminant Level Goal (MCLG) = zero

Health Effects
Some people who drink water containing polychlorinated biphenyls in excess of the MCL over many years could experience changes in their skin, problems with their thymus gland, immune deficiencies, or reproductive or nervous system difficulties, and may have an increased risk of getting cancer.

Drinking Water Health Advisories provide more information on health effects

Chemical Abstract Service Registry Number
1336-36-3

Sources of Contamination
Runoff from landfills; discharge of waste chemicals

List of all Regulated Contaminants (PDF) (6 pp, 396 K, About PDF)

EPA regulates polychlorinated biphenyls in drinking water to protect public health. Polychlorinated biphenyls may cause health problems if present in public or private water supplies in amounts greater than the drinking water standard set by EPA.

What are polychlorinated biphenyls?
Polychlorinated biphenyls are a group of organic chemicals which can be odorless or mildly aromatic solids or oily liquids.

Uses for polychlorinated biphenyls.
Polychlorinated biphenyls were formerly used in the United States as hydraulic fluids, plasticizers, adhesives, fire retardants, way extenders, de-dusting agents, pesticide extenders, inks, lubricants, cutting oils, in heat transfer systems, carbonless reproducing paper.

If you are concerned about polychlorinated biphenyls in a private well, please visit:

What are polychlorinated biphenyls's health effects?
Some people who drink water containing polychlorinated biphenyls well in excess of the maximum contaminant level (MCL) for many years could experience changes in their skin, problems with their thymus gland, immune deficiencies, or reproductive or nervous system difficulties, and may have an increased risk of getting cancer.

This health effects language is not intended to catalog all possible health effects for polychlorinated biphenyls. Rather, it is intended to inform consumers of some of the possible health effects associated with polychlorinated biphenyls in drinking water when the rule was finalized.

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How is polychlorinated biphenyls regulated?
In 1974, Congress passed the Safe Drinking Water Act. This law requires EPA to determine safe levels of contaminants in drinking water which do or may cause health problems. These non-enforceable health goals, based solely on possible health risks and exposure over a lifetime, are called maximum contaminant level goals (MCLG). Contaminants are any physical, chemical, biological or radiological substances or matter in water.

The MCLG for polychlorinated biphenyls is zero. EPA has set this level of protection based on the best available science to prevent potential health problems.

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What are EPA's drinking water regulations for polychlorinated biphenyls?
EPA has set an enforceable regulation for polychlorinated biphenyls, called a maximum contaminant level (MCL), at 0.0005 mg/L or 500 ppt. MCLs are set as close to the health goals as possible, considering cost, benefits and the ability of public water systems to detect and remove contaminants using suitable treatment technologies.

The Phase II Rule, the regulation for polychlorinated biphenyls, became effective in 1992.  The Safe Drinking Water Act requires EPA to periodically review the national primary drinking water regulation for each contaminant and revise the regulation, if appropriate. EPA did review polychlorinated biphenyls as part of the Six Year Review and determined that the zero MCLG and 0.0005 mg/L or 500 ppt MCL for polychlorinated biphenyls are still protective of human health.

States may set more stringent drinking water MCLGs and MCLs for polychlorinated biphenyls than EPA.

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How does polychlorinated biphenyls get into my drinking water?
The major sources of polychlorinated biphenyls in drinking water are runoff from landfills; and discharge of waste chemicals.

A federal law called the Emergency Planning and Community Right to Know Act (EPCRA) requires facilities in certain industries, which manufacture, process, or use significant amounts of toxic chemicals, to report annually on their releases of these chemicals. For more information on the uses and releases of chemicals in your state, contact the Community Right-to-Know Hotline: (800) 424-9346.

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How will I know if polychlorinated biphenyls is in my drinking water?
When routine monitoring indicates that polychlorinated biphenyls levels are above the MCL, your water supplier must take steps to reduce the amount of polychlorinated biphenyls so that it is below that level. Water suppliers must notify their customers as soon as practical, but no later than 30 days after the system learns of the violation. Additional actions, such as providing alternative drinking water supplies, may be required to prevent serious risks to public health.

If your water comes from a household well, check with your health department or local water systems that use ground water for information on contaminants of concern in your area.

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How will polychlorinated biphenyls be removed from my drinking water?
The following treatment method(s) have proven to be effective for removing polychlorinated biphenyls to below 0.0005 mg/L or 500 ppt: granular activated carbon.

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How do I learn more about my drinking water?
EPA strongly encourages people to learn more about their drinking water, and to support local efforts to protect the supply of safe drinking water and upgrade the community water system. Your water bill or telephone book's government listings are a good starting point for local information.

Contact your water utility. EPA requires all community water systems to prepare and deliver an annual consumer confidence report (CCR) (sometimes called a water quality report) for their customers by July 1 of each year. If your water provider is not a community water system, or if you have a private water supply, request a copy from a nearby community water system.

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