Environmental Health, Environmental Justice
Well water quality in Maryland: Results of a pilot study to analyze private drinking water wells and educate homeowners
(School of Public Health (UMD) Maryland Institute for Applied Environmental Health (MIAEH) Doctoral Student)
An estimated 1 million Maryland residents rely on private wells for drinking water. The Safe Drinking Water Act (SDWA) protects public health by regulating the nation's public drinking water supply; however, private wells that serve less than 25 people are not regulated by SDWA. In 2012 a collaborative team of University of Maryland (UMD) Extension professionals and UMD researchers launched a pilot project to analyze water quality and educate homeowners in Maryland. Safe Drinking Water Clinics were conducted for private well owners in four counties and included training on collection of well water samples. A survey also captured the current knowledge base of residents and included questions on well characteristics and management practices. Well water samples were collected by clinic participants (n=117) and analyzed for total coliforms, fecal coliforms, E.coli, Enterococcus, Salmonella, total dissolved solids (TDS), pH, nitrates, sulfates and total arsenic. We also evaluated whether certain well characteristics and proximity to animal feeding operations influenced well contamination using logistic regression models in SAS 9.2. 24% (28/117) of wells tested positive for total coliform bacteria, while fecal coliforms were detected in 15% (18/117) of samples. E. coli was detected in 3% of samples and Enterococcus in 5% of samples. 4% of wells exceeded the EPA maximum contaminant level (MCL) for nitrate, 1% of wells exceeded the MCL for TDS, and 26% of wells exceeded the recommended range for pH. Well characteristics did not impact the presence of total coliform bacteria in tested wells. Samples from zip codes with cattle operations had significantly higher odds of being positive for total coliforms compared to those from zip codes without cattle operations (OR: 1.702; 95% CI: 1.130- 2.561). This study will continue in 2015 in order to reach additional private well owners and build a database on private well water quality in Maryland.
Importance to public health: