Private Drinking Water Wells

water sampling

Expanding its research on hormonal pollutants leaching from septic systems into groundwater and public drinking water supplies on Cape Cod, Silent Spring Institute conducted a study of pharmaceuticals, hormones, and household chemicals in private drinking water wells.

Institute researchers partnered with Cape Cod residents with private wells who volunteered to participate. Well water samples from 20 private wells in seven towns were tested for over 100 emerging contaminants, including pharmaceuticals, hormones, personal care products, herbicides, alkylphenols, flame retardants, and highly fluorinated chemicals. The results were published in the journal Science of the Total Environment.

The 27 contaminants detected included pharmaceuticals (the most common being an antibiotic and an epilepsy drug), highly fluorinated chemicals (found in non-stick and stain-resistant household products), flame retardants, hormones, a skin care product, an artificial sweetener, an insect repellent, and a plastics additive. The most frequently detected chemical was acesulfame, an artificial sweetener, which was found in 85 percent of wells.  Seventy percent of wells contained at least one highly luorinated chemical.

Health-based guideline values were available for only four chemicals detected in this study, and no samples approached or exceeded these values.  However, most of the target chemicals are not currently regulated in drinking water and the health effects of low levels of exposures are not known.

“Our results demonstrate the widespread impact of wastewater, primarily from septic systems, on Cape Cod drinking water quality,” said Dr. Laurel Schaider, a research scientist at Silent Spring Institute and the study director. “Many Cape communities are facing challenging decisions about reducing the impact of nutrients from wastewater on Cape water quality. These findings clearly show that the issue of emerging contaminants also needs attention.”