Manganese. Arsenic. Dioxane. In all, eight substances, including PFAS, were found in the groundwater around the old landfill at levels that exceed various state and federal drinking water standards.
The Massachusetts Department of Environmental Protection is requiring Harvard to officially close the old landfill that was located in the area behind the trash compactors at the Transfer Station. The town stopped using the landfill in 1984. Part of that process includes groundwater monitoring, and in March, seven monitoring wells were installed near the old landfill. The water was tested for 23 substances and 17 PFAS—an abbreviation for per- and polyfluoroalkyl substances—in April. The town recently received the first round of test results.
Groundwater from four of the seven wells showed PFAS levels over the state’s maximum contaminant level of 20 parts per trillion (ppt) for the sum of six substances: PFOS, PFOA, PFHpA, PFHxS, PFNA, and PFDA, collectively known as PFAS6. Two of the wells had levels 10 times higher than the state’s maximum, while the other two were only slightly over the maximum. Those same four wells also had levels of PFOA and PFOS that exceeded the EPA’s new maximum contaminant level of 4 ppt for each of those two substances. The PFOA level in one well was 135 ppt and 83.7 ppt in another.
The level of arsenic in one of the wells, 104 micrograms per liter, also exceeded the state’s maximum contaminant level of 10 micrograms per liter.
Secondary contaminants
MassDEP also has standards for contaminants that affect the aesthetic properties of drinking water, such as taste, odor, or color. The state uses the federal Environmental Protection Agency’s guidelines called secondary maximum contaminant level (SMCL) for these substances.
About half of the wells had levels that exceeded the SMCL for iron, chloride, and total dissolved solids. Iron, which affects the taste and color of water and can cause staining, was found at a level of 13,400 micrograms per liter in one well; the SMCL for iron is 300 micrograms per liter. In another well, chloride, which affects the taste of water and can contribute to pipe corrosion, was nearly 10 times the SMCL of 250 milligrams per liter. That same well had a level of total dissolved solids, which have a metallic taste and can corrode pipes and stain plumbing fixtures, more than seven times the SMCL of 500 milligrams per liter.
More concerning is the high levels of manganese found in six of the seven wells. MassDEP’s Office of Research and Standards has also established guidelines (ORSGs) for some substances that do not have a maximum contaminant level but have been shown to be a health risk. Manganese is one of those substances, and its ORSG is 300 micrograms per liter. Test results from four of the seven wells showed manganese levels over 1,000 micrograms per liter, with the level in one of those wells at 16,700 micrograms per liter. According to the Centers for Disease Control and Prevention, “extremely high levels of manganese exposure may produce undesirable effects on brain development, including changes in behavior and decreases in the ability to learn and remember.”
Dioxane 1,4 is another substance with an ORSG of 0.3, and the CDC reports that drinking water with the substance can cause liver and kidney damage. The level of dioxane 1,4 in one well was 0.46.
Elevated sodium
The water in the ground under the Department of Public Works is salty. Very salty. Six of the seven monitoring wells exceeded the ORSG for sodium, which is 20,000 micrograms per liter. Two of the wells had over 1,000,000 micrograms per liter.
In 1984, residents on Mill Road across the street from the DPW complained to the town about salty drinking water from their private wells. The water was tested, and sodium levels were high, although the Press could not obtain the test results. The source of the salt in the water was thought to be road salt stored in uncovered piles at the DPW. The town installed a new private well near the baseball field on Depot Road to provide water for three Mill Road residents as well as the DPW facility. It also built a shed for road salt storage. It is unclear whether the high sodium levels in the groundwater tests are from that 40-year-old salt contamination, or if road salt is still leaching into the water from the area around the facility.
Source of the other contaminants?
Leachate, the substance that is released when landfill waste soaks up rainwater and releases its chemicals into that water before the water soaks into the ground, could be responsible for at least some of the groundwater contamination in the area around the DPW.
Town officials initially thought the landfill occupied only the area behind the trash bins at the Transfer Station. But in 2023, buried trash, some nearly 10 feet deep, was found near the pole barn during geotechnical testing that was done during the initial design and estimate for a new facility. Since then, underground trash has been found along all the boundaries of the Transfer Station, including behind the metal pile, as well as alongside the chain link fence that separates the DPW facility from the soccer fields on Depot Road.
Town Administrator Dan Nason reported the monitoring well test results to the Select Board at its May 20 meeting, saying that the levels of several compounds, including PFAS, were considered “reportable” by MassDEP. Nason also said multiple contaminants listed on the Massachusetts Oil and Hazardous Materials list, including arsenic, barium, cadmium, lead, sodium, zinc, PFAS, and diethyl ether were found in surface water samples also taken from the area around the old landfill. The town is waiting for further direction from MassDEP.
