Health Indicator Report of Gross Alpha in Private Wells
Gross Alpha is a test that is performed to measure the overall radioactivity in drinking water. Naturally occurring radioactive elements emit alpha particles as they decay. Alpha radiation exists in soil, air, and water. Sampling of public and private wells that draw water from southern New Jersey's Cohansey aquifer has shown elevated levels of naturally occurring radioactivity. Exposure to radium over a long period of time is believed to increase one's lifetime risk of developing certain types of cancer.
Gross Alpha in Private Wells, Percent of Tested Wells Exceeding MCL, by County, Sept 2002 - April 2014
NotesGross alpha testing of private wells is required in these 12 NJ counties under the NJ Private Well Testing Act. Denominator is the number of tested private wells. Data Source: NJ Department of Environmental Protection, Division of Water Supply and Geoscience, and Division of Science, Research, and Environmental Health, Private Well Testing Act Data Summary page, [http://arcg.is/1CPkHyC], obtained on July 6, 2016.
Data Interpretation IssuesGross alpha particle activity is a surrogate measurement for radium and is a measurement of all alpha radioactivity present, regardless of the specific radionuclide source. The federal maximum contaminant level (MCL) for gross alpha is 15 pCi/l minus the contribution from uranium. Nine southern New Jersey counties in the Coastal Plain (Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester, Monmouth, Ocean, and Salem) and three northern counties (Hunterdon, Mercer, and Middlesex) are required to monitor for gross alpha. In the Coastal Plain, where the only radionuclide present is radium, this surrogate test works well. However, outside of the Coastal Plain, groundwater samples may contain uranium, radium, or a combination of both. Both elements emit alpha radioactivity and so gross alpha measurements do not provide sufficient information to determine whether a particular sample exceeds the drinking water MCL. Of all of the private wells sampled statewide, 10.1 percent contained gross alpha levels above the federal MCL. In the Coastal Plain, 11.5 percent of private wells tested contained levels of gross alpha above the federal MCL.
DefinitionPercent of tested private wells with gross alpha exceeding the maximum contaminant level of 15 picoCuries per liter(pCi/l)
NumeratorNumber of tested private wells with gross alpha concentration exceeding the maximum contaminant level of 15 pCi/l in a specified period of time
DenominatorNumber of tested private wells in a specified period of time
How Are We Doing?Between September 2002 and April 2014, 10.1% of 48,315 private wells in New Jersey tested for gross alpha exceeded the MCL of 15 pCi/l. Gross alpha exceedances were most commonly found in Camden (34.4% of wells), Cumberland (28.2% of wells), Salem (15.4% of wells), Gloucester (11.1% of wells), and Atlantic Counties (10.9% of wells). Online maps showing gross alpha exceedances are available at the county level, municipal level, and for 2 mile by 2 mile grids from NJDEP, http://arcg.is/1CPkHyC
What Is Being Done?The New Jersey Private Well Testing Act (N.J.S.A. 58:12A-26 et seq.) became effective in September 2002. The PWTA requires the buyer or the seller of a property to test untreated well water prior to the sale and review the results prior the closing of title. It also requires landlords to test the private well water supplied to their tenants every five years and provide their tenants with a written copy of the results. The data generated by this program are provided to the homeowners by the laboratory performing the analyses and then sent to the New Jersey Department of Environmental Protection (NJDEP). The NJDEP notifies local health agencies when a well within their jurisdiction is tested under the PWTA. The data from the PWTA are used by NJDEP to assess the quality of the water from private wells throughout the state.
Available ServicesIf 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 the NJDEP Office of Quality Assurance at (609) 292-3950 for information on laboratories certified to test drinking water or look for the information online at: [https://www13.state.nj.us/DataMiner] using the "Search by Category" option, select "Certified Laboratories", and search for "Certified Drinking Water Labs", "PWTA Laboratories Certified for Sampling", or "Laboratories Certified by Parameter". Testing is required for sale of residential real estate when a private well is the source of drinking water. For more information, contact the NJDEP Private Well Testing Program at (866) 479-8378 or visit: [http://www.nj.gov/dep/watersupply/pw_pwta.html] Private Well Testing Act Frequently Asked Questions: [http://www.nj.gov/dep/watersupply/pwta/pwta_faq.htm] NJ Private Well Testing Act Data Summary, by county, municipality, and 2 mile by 2 mile grid: [http://arcg.is/1CPkHyC] NJDEP, A South Jersey Homeowner's Guide to Radioactivity in Drinking Water, [http://www.nj.gov/dep/rpp/rms/agreedown/radwater.pdf] NJDOH, Drinking Water Facts: Private Wells, [http://www.nj.gov/health/ceohs/documents/eohap/pw_faq.pdf] NJDOH Drinking Water and Public Health Project, [http://www.nj.gov/health/ceohs/sanitation-safety/drinking-water-public-health/]
Page Content Updated On 07/14/2016, Published on 08/25/2017