The Board of Health has expanded the regulation for water quality testing on all new and altered wells to include a “gross alpha screen,” which detects the presence of radioactive particles and determines whether further testing is needed for uranium or radium. The new requirement comes in the wake of a recent U.S. Geological Survey (USGS) study that identified areas in Harvard that are at increased risk for low-level radioactivity in water from bedrock wells.
The USGS uranium risk map identifies a zone on the western side of a line that runs northeast to southwest, passing almost directly through the center of Harvard. The probability that uranium levels will be higher than the standard for public drinking water in that zone is between 4.8 and 13 percent. Uranium and radium occur naturally in bedrock, and as they decay, they emit alpha particles that can enter the groundwater through rock fractures. The gross alpha test measures the level of those particles in water, indicating that the water may also contain uranium, radium, or both.
Two wells over, public water under
Over the past few weeks, three new wells were tested for gross alphas, and two of the three tested higher than the regulation’s limit of 15 picocuries per liter. As a result, the water from both of those wells is now being tested for radium 226, radium 228, and uranium. One of the wells is on Depot Road; the other is on Ayer Road. Department of Public Works Director Rich Nota confirmed that both public water supply wells on Pond Road, which lie on the border of the higher uranium zone, were tested in 2015. Both were below the regulation’s gross alpha limit.
The board defines the maximum allowable level of uranium in drinking water to be 30 micrograms per liter, and 5 picocuries per liter for radium. If uranium or radium levels are higher than the maximum allowed, the board requires a remediation plan as well as retesting to make sure that remediation has been successful. In addition, a notice must be recorded on the deed when the property is sold.
Radon in well water
Radon, another radioactive element, is a gas produced from the natural breakdown of uranium or radium and can also be present in well water, but its presence is not definitively predicted by the gross alpha test. The board already has a policy in place for radon in drinking water. It defines the maximum allowable level to be 10,000 picocuries per liter. Levels above that require remediation, retesting to show that remediation is working, and notification on the property deed. Levels between 4,000 and 10,000 picocuries per liter require notification to the Board of Health and periodic retesting.
Uranium and radium are health hazards only if they are ingested either in high concentrations or over a long period of time. The primary health effect of uranium is kidney damage, while radium may result in an increased risk of bone cancer, leukemia, and lymphoma. Radon, the second leading cause of lung cancer in the U.S., is of greatest risk if inhaled. Radon in well water can enter the air in a home from faucets, showerheads, dishwashers, and clothes washers.
Periodic testing recommended
Nashoba Associated Boards of Health sanitarian Ira Grossman said in an interview that he recommends that all residents test their water periodically, including gross alpha testing. The board also recommends that all private well water be tested for gross alpha particles prior to any sale of the property. Tests should be conducted by a lab certified by the Massachusetts Department of Environmental Protection. The closest such laboratory to Harvard is Nashoba Analytical in Ayer, which currently charges $75 for gross alpha testing.
More information, including the USGS uranium risk map, can be found on the Board of Health page on the town website: www.harvard.ma.us/Pages/HarvardMA_BComm/BOH/index.
