Pre-drill Water Quality Data Demonstrates the Importance of Private Water Supply Testing (Part 2 of 2)

Posted: May 13, 2012

Many people with a private water well have never or seldom have their well water tested. Pre-drilling water testing provides homeowners with useful information on their water wells as well as helpful research data. Part 2 provides some of the data found.

As mentioned last week, the collective water quality data provided by the industry correlates closely with previous studies conducted in the area by Penn State Extension. Previous studies and current results show that many private water supplies in Pennsylvania fail at least one water quality standard - and many of these pre-existing conditions warrant the attention of the homeowner.

Manganese, for example, is detected above the recommended maximum contaminant level in approximately 1/3 of the industry samples locally; while iron is in excess of the recommended drinking water standard in about a quarter of the samples collected by the industry. Statewide, Penn State data found a 27% and 20% exceedance rate for manganese and iron, respectively. But, while manganese and iron are considered secondary (not health threatening) contaminants, other naturally-occurring health-adverse contaminants like arsenic and barium show up in about 1 of every 30 water wells tested by the industry in northeastern PA.  Penn State’s research shows about a 1% incidence rate for barium and 4% for arsenic. Lead detections above the drinking water standard occur in about 3% of the local wells according to one operator’s data set and another operator, also working in the area, reports a 6% lead  exceedance rate, albeit with a much smaller data set.  Statewide, about 6% of lead tests exceed the standard according to Penn State Extension’s research. 

Methane, rarely tested by private landowners nor by Penn State Extension before Marcellus shale drilling came to Pennsylvania, was detected in approximately 20+% of the water wells tested locally by industry prior to drilling while our most recent Penn State research, funded by the Center for Rural Pennsylvania1, revealed a similar finding across the study area (about 20%). Methane levels below 10mg/L are generally considered safe and the 98% of the detections by Penn State Extension were below this level action level.

The gas industry usually doesn’t test for bacteria but we know from previous studies that bacteria are the most prevalent contaminant of private water supplies, and in Pennsylvania, Penn State’s research suggests 33% - 40% of the wells fail this water quality parameter. Although limited, the data available from the natural gas industry matches the Penn State Extension findings.

Regardless of how it’s paid for, or the impetus for it to occur, (regular) testing is key to the good management of a private water supply. For some, the testing provided by the natural gas industry is the first test of their private water supply.  For others, the more extensive array of parameters analyzed by the industry might have expanded upon previous tests done by the homeowner.  The identification of excessive contaminant levels in pre-drilling water samples is arguably an unaccounted for benefit of Marcellus shale development.  Problems discovered by the testing can now be corrected. The impact of the previously unknown contaminant(s) will most likely remain unknown.

In the future, pre-drill water testing presents a continuing opportunity to help landowners discover the quality of their water and to determine management strategies and appropriate treatment options. And, to that extent it may improve the health and well-being of many rural Pennsylvanians living in the shale fields.

written by Mark Madden, Penn State Educator