New Jersey Environmental Public Health Tracking Program

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Drinking Water Quality

Drinking Water QualityThe New Jersey EPHT program, working in close partnership with the NJ Department of Environmental Protection (NJDEP), has summarized data on water quality for over 600 community water systems in New Jersey, as well as on water quality for numerous private wells.  Community water systems provide drinking water to more than 85% of the state’s population.  The New Jersey EPHT Network currently contains information on disinfection by-products for community water systems (trihalomethanes and haloacetic acids), and arsenic and nitrate in both community water systems and private wells.

What Information Does the EPHT Network Contain About Drinking Water Quality in New Jersey?


Arsenic (As) is a naturally-occurring element in the earth’s crust and was used in the past as a pesticide.  Elevated arsenic levels found in some groundwater sources in New Jersey are most likely from natural sources.  Arsenic has been classified as a known human carcinogen, based on human epidemiological data, and can also cause other health effects. 

Disinfection by-products:

Disinfection by-products (DBPs) are formed when disinfectants, such as chlorine used during water treatment to destroy harmful bacteria and viruses, react with natural organic matter in water. A wide variety of DBPs are formed, but only trihalomethanes (THMs) and haloacetic acids (HAAs) are typically measured since they are produced in the largest amounts.


Nitrate may be found in drinking water as a result of the use of fertilizers on agricultural lands.  Exposure to high levels of nitrate in drinking water may result in a condition, particularly in infants, in which the blood is unable to carry sufficient amounts of oxygen.

To view a list of additional water system contaminant data, click here to go to the index of EPHT indicator reports and select the + symbol next to Drinking Water Quality.

Where Can I Get More Information about my Own Drinking Water Quality?

If your drinking water comes from a public community water system:
Your water supplier is required by law to test it to ensure that it meets state and federal Maximum Contaminant Levels (MCLs).  Most MCLs are set by the US Environmental Protection Agency, but in New Jersey many MCLs are set more stringently by the NJDEP.  The MCLs are based on information on health effects, treatment, analytical methods and contaminant occurrence.  You can get the most recent test results for your water system by contacting your water supplier or the NJDEP Division of Water Supply and Geoscience at (609) 292-5550. 

If your drinking water comes from a private well:
You are responsible for testing.  The NJDEP recommends that you use a laboratory that is NJDEP-certified. You can call NJDEP Office of Quality Assurance at (609) 292-3950 for information on laboratories certified to test drinking water.  In New Jersey, testing is required for sale of residential real estate when a well is the source of water.  For more information, contact the NJDEP Private Well Testing Program or call (866) 479-8378.

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