Environmental monitoring

The Radiation Control Program (RCP) conducts environmental radiation monitoring within the 10-mile Emergency Planning Zones (EPZs) of operating nuclear power stations in or near the Commonwealth as part of our regulating responsibilities.

Nuclear Power Plant Emergency Planning Zones

Within the Emergency Planning Zones of active nuclear power plants, RCP monitors radiation levels in samples of environmental media including:

  • Food crops
  • Milk
  • Surface water
  • Sediment and biota (seaweed and grasses)
  • Fish and Shellfish
  • Air

The Massachusetts Environmental Radiation Laboratory (MERL) analyzes the samples collected and the Environmental Toxicology Program (ETP) reviews and interprets the results from a human health and exposure perspective.

The Bureau of Climate and Environmental Health has a network of stationary monitors surrounding Pilgrim Nuclear Power Station that measure gamma radiation in real-time and transmit the data to a computer monitored by DPH staff. If radiation is detected above typical background levels, DPH receives emergency text alerts. The alerts ensure that immediate actions can be taken if necessary. Real-time air monitoring is also done by the C-l 0 Research & Education Foundation, Inc., a non-profit under contract with DPH, in the Massachusetts communities within the Seabrook EPZ.

Environmental monitoring reports and presentations are provided below.

Additional Resources

Tritium in Groundwater Monitoring at Pilgrim Nuclear Power Station


2006: The Nuclear Entergy Institute proposed that nuclear power plants begin a voluntary groundwater protection initiative aimed at monitoring for tritium in groundwater. In response, Entergy began monitoring for tritium in groundwater in 6 monitoring wells at Pilgrim Station in 2007.

2010: In response to tritium in groundwater findings at the Vermont Yankee Power Plant in VT, Pilgrim installed 6 additional groundwater monitoring wells. Based on increased tritium measured at one well, (MW205) in 2010, and review of available groundwater information at Pilgrim Station, DPH recommended that Entergy develop a comprehensive plan to identify tritium sources, install additional monitoring wells, and increase communication between DPH, Entergy, and Massachusetts Emergency Management Agency (MEMA) representatives.

From 2010 to the present: Entergy has continued to monitor for tritium and investigate possible sources. Currently, Entergy collects samples at 23 groundwater wells and one surface water location and analyzes them for tritium. Sampling intervals are based on past monitoring results and review of possible pathways for tritium in groundwater. Samples are sent by Entergy to an independent analytical lab, and duplicate samples are analyzed at the Massachusetts Environmental Radiation Lab (MERL). Updates summarizing groundwater monitoring activities are provided by year below.

View all updates on the tritium investigation, laboratory results, and approximate locations of monitoring wells.

Contact   for Environmental monitoring


250 Washington St., 7th Floor, Boston, MA 02108

Help Us Improve Mass.gov  with your feedback

Please do not include personal or contact information.