Pre-drill Water Quality Data Demonstrates the Importance of Private Water Supply Testing
Posted: April 16, 2012
State law defined in the Oil and Gas Act of 1984 regulates oil and gas drilling in the commonwealth. Recent amendments to the law have refined the act to account for the unique circumstances involved with developing unconventional oil and gas resources from shale. An important section (208) of the law addresses the protection of drinking water supplies.
The law requires operators to follow specific practices to protect ground and surface water supplies while developing the natural gas resource. Perhaps the most important aspect of the law presumes operators to be responsible (for up to a year after a gas well is drilled) for any impairment of a private water supply within 2500 ft of their drilling operation. Furthermore, the law requires an operator to restore or replace any private or public water supply deemed impaired by the Pa. Dept. of Environmental Protection. As a result, responsible operators make efforts to limit their liability by collecting pre-drilling water samples from landowners near proposed gas well locations. Typically, a landowner is asked to grant access to a consultant hired by the driller to collect the samples before drilling occurs in the area. Once collected, the consultants deliver the samples to an accredited laboratory for analysis. While the samples are collected and analyzed in a legal context to protect the driller, the results also have utility for the landowner. A landowner may duplicate or extend this testing on their own, but must use a third party sampler and a DEP-accredited laboratory for results to be considered as legal evidence of their pre-drilling water quality.
In the absence of state law regarding water well construction standards and minimum consumptive quality standards, Penn State Extension has long advocated for the wise management of private water systems. Perhaps the most common theme to our educational message has been to encourage landowners to routinely test their private water supplies. Testing, and reacting appropriately to any contaminant found at harmful levels, remains the measure of our educational objectives and impact.
Penn State research prior to Marcellus shale development has found that only half of the private water supplies in the state have been tested, and fewer still have been tested regularly. A result of the natural gas development has been a significant number of private water systems being tested for the first time. Statewide to date, tens of thousands of water tests have been completed by the natural gas drilling companies. One company alone has collected over 18,000 samples in Tioga, Bradford, Susquehanna and Sullivan Counties. Other companies, working in the same area, have added significantly to the total number of tests run.
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 PA, 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.
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.