This week, the federal Agency for Toxic Substances and Disease Registry (ATSDR), a part of the Center for Disease Control (CDC), released its findings on the U.S. Environmental Protection Agency’s (EPA) data from water testing in Dimock, Pennsylvania over a six-month period in 2012. Although the owners of the 64 wells tested were given reports and met with officials from ATSDR and EPA back in 2012, the data has only been released to the public this week.
Activists are already jumping on this report claiming it finds contamination from fracking, but at no point does the agency link these findings to oil and gas development in the region.
Here are some important facts from the 121-page report:
Fact #1: Report does not link water issues to fracking
First and foremost, ATSDR does not link water issues to fracking in the area. In fact, it is very clear that it did not consider the sources of the contamination as part of its evaluation. From the report,
“For this public health evaluation, ATSDR conservatively assumed ingestion of residential well water with the maximum detected chemical concentration(s) and included all detected contaminants in the evaluation regardless of the source of the contaminant in the residential well (e.g., naturally occurring or otherwise). Per ATSDR’s health assessment process, ATSDR made conservative assumptions about exposures to the chemicals detected in the residential well water at this site, and made recommendations based on this information.”
It also wasn’t ATSDR’s job to determine whether or not nearby gas drilling was responsible for the contaminants. E&E News quoted Bryce Payne, a Pennsylvania environmental scientist who has studied aspects of the Dimock case: “It’s not their job to look at who caused whatever contamination there is. It’s their job to see if there are health implications.”
Fact #2: Study does not include baseline data; admits numerous limitations
As ATSDR explains when discussing limitations in the report, the agency did not evaluate baseline samples,
“There is a lack of pre-drilling data for comparison to post-drilling residential water well data, or for chronic exposure evaluations. Methane, industry-specific chemicals, and many metals were typically not assessed prior to the start of natural gas activities in the Dimock area.” (emphasis added)
In addition to this, ATSDR describes a variety of other limitations to its analysis including,
“The majority of the environmental sampling data reviewed in this document are limited temporally to a six month period of time in 2012 when a moratorium was in place for natural gas drilling and completion activities in the site area. This time- and condition-limited data may not represent past, current or future exposures for Dimock area residents consuming groundwater.” (emphasis added)
That’s just the beginning of the studies stated limitations, which include:
- Samples may not have been reported with precise or accurate concentrations, particularly for polycyclic aromatic hydrocarbons (PAHs)
- ATSDR did not review the original laboratory analytical packages.
- “Information on pH, total dissolved solids (TDS), and odor was not consistently collected and documented during EPA 2012’s assessment activities.”
- “Information on potential pathways of exposure beyond the groundwater pathway (e.g., ambient air inhalation) is not available to ATSDR for this site at this time.”
- “There is limited toxicological information on the effects of exposures to metal salt mixtures in drinking water.”
So ATSDR had no way to make a comparison between past issues or the current state of these wells without baseline data. The agency was also given the data secondhand—researchers did not take their own samples—which limited its understanding of certain inconsistencies and may have impacted the accuracy of the information, forcing assumptions to be made at times.
Fact #3: Numerous studies have shown historic water issues throughout the Pennsylvania Marcellus Shale region.
While this study didn’t evaluate baseline data, historic information and baseline water testing in the region is available. In fact, in 2013 a study published in the peer-reviewed journal for the National Groundwater Association looked at over 1700 wells in Susquehanna County and found:
- “Historical documentation suggests that the presence of methane gas in the shallow subsurface has been observed for over 200 years in Susquehanna County…”
- “There are several dozen instances of flammable effervescing springs and water wells dating back to the late 1700’s…”
- “Water well drillers have frequently reported encountering gas during drilling, particularly in valleys and other low-lying areas…”
It went on to explain,
“The results of the extensive ‘predrill’ water well sampling and background survey show methane to be nearly ubiquitous in water wells in this region, with over 78% of the water wells exhibiting detectable methane concentrations.” (p. 3, emphasis added)
Further, the most comprehensive analysis of baseline water tests to date, conducted by Syracuse University, looked at over 21,000 water samples in the Norther Tier, where Dimock is located, and found that,
“…exceedance of at least one water-quality standard occurs in 63% of water well samples in NE Pennsylvania and 87% in the Western area.”
“My opinions are that the plaintiff’s water wells contain naturally occurring compounds, natural compounds consistent with background, ground water condition. I didn’t see anything outside the range of what I would call bad ground water condition. These wells are not impacted by gas well operations.”
So yes residents in the region have known that they have water issues for quite some time – generations even.
Fact #4: The identified chemicals could be from a variety of sources.
One of the interesting parts in the report is that for each contaminant, ATSDR lists places where it is found. So for instance, it explains,
“Manganese is a naturally occurring substance found in many types of rock and soil…In addition to its natural origin, manganese can be found in groundwater as a result of its use in industrial activities and manufacturing, such as production of batteries, pesticides, and fertilizers.” (page 38)
Or that Di-ethylhexyl phthalate (DEHP), is
“the most commonly used plasticizing agent for the widely used plastic polyvinylchloride (PVC). Consequently, this compound is found everywhere in the environment of civilization, where it is in frequent contact with every person.” (page 21)
The report does this for each contaminant that had elevated levels in any household, and while ATSDR makes no attempt to say what did in fact cause each one, the information is helpful in showing that the compounds are often found naturally or through items on or near our properties.
The people who need to see this information — those individuals who had some compound in their water — have had it for many years and have already had one-on-one conversations with EPA and ATSDR about these issues. At the end of the day, this report, while interesting in what it explains about certain compounds found in our region’s water supply, isn’t going to open any new chapters on Dimock.