Expert reports many water wells in Pa. do not meet safe water standards


UNIVERSITY PARK, Pa. — A Penn State Extension water specialist told a House committee Jan. 10 that research has shown about 40 percent of all water wells in the state fail to meet at least one safe-drinking-water standard.

Bryan Swistock, senior water resources extension associate at Penn State, testified before the House Consumer Affairs Committee in a hearing on House Bill 1855, which would create standards for water-well construction. Pennsylvania is currently one of just a few states that do not have statewide requirements for the construction of private water wells.

“While proper well construction does not completely eliminate water-quality problems, it clearly plays a role in preventing surface contaminants from getting into wells,” he said. “Our research has shown that inadequate water-well construction is a contributing factor to the failure of some private wells to meet safe-drinking-water standards.”


Swistock noted that for the past 23 years he has conducted both research and outreach programs offered by Penn State’s College of Agricultural Sciences related to private water wells in Pennsylvania.

“We recognize that private water wells are a critical part of the water infrastructure in Pennsylvania, providing drinking water to millions of residents in rural homes, farms and businesses,” he testified.

“In the absence of both regulatory protections and unbiased assistance, Penn State has devoted considerable research and extension efforts to meet the demands of private well owners interested in properly constructing and managing their drinking water supply.”

Over the past three decades, Swistock pointed out, the university has conducted numerous research projects on various aspects of water quality that have included thousands of private water wells.

“Our research has consistently found that approximately 40 percent of private water wells in Pennsylvania fail to meet at least one safe-drinking-water standard,” he said. “The most frequently detected pollutant with a potential health effect is coliform bacteria, which occurred in about one third of the water wells tested in our research.

“The presence of these bacteria indicates the potential for disease-causing bacteria to occur in drinking water. E. coli bacteria, which originate from either animal or human wastes and thus represent a more serious health risk, were found in 14 percent of the water wells in our recent study.”


While these bacteria can be related to various land uses near water wells, they also can occur from surface water, insects or small mammals entering poorly constructed wells, Swistock explained.

This surface contamination often can be prevented by extending a properly sized well casing above the ground surface, installing a cement-like grout seal around the casing, and fitting the top of the casing with a vermin-proof or “sanitary” well cap.

According to Swistock, recent Penn State research found that many water wells lack at least one of these water well features.

“More importantly, this same research showed a statistical correlation between water-well construction and the occurrence of both coliform bacteria and E. coli bacteria in the well water,” he said.

“Bacterial contamination rates in water wells with sanitary construction were about half of the rates found in water wells that lacked any sanitary construction components.”


An earlier, small-scale Penn State study found that some bacterial contamination in water wells could be removed simply by having a water-well professional disinfect the well and replace loosely fitted well caps with a sealed, sanitary well cap. Unfortunately, many rural residents are unaware of water-quality problems, Swistock told the committee.

Most bacteria problems and similar problems with health-related pollutants in water wells often are discovered only after proper testing by a state-accredited laboratory and interpretation of these water-test records.

“Several of our research projects have shown that homeowners with water wells that fail at least one health-based drinking water standard are typically unaware that their water is unsafe,” he said.


Just as one example, of the 203 water wells that contained unsafe levels of coliform bacteria in our 2006 study, only 11 percent were aware of this problem before our study.

“We have found that about one-third of water-well owners have never had their water tested properly by a state-accredited laboratory, and many who have done testing don’t understand the meaning of the results.”

Inadequate water well construction and the lack of awareness of water-quality problems by well owners represent significant potential health risks among the millions of rural residents, farmers and businesses that access the shared groundwater resource, Swistock concluded.


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