A study published by New Solutions, A Journal of Environmental and Occupational Health Policy, examines the impact of the unconventionall gas industry on dairy production in Pennsylvania.
Unconventional drilling increased substantially in Pennsylvania between 2007 and 2011. The study found that during this period milk production and milk cows decreased in the five counties with the most wells drilled, compared to six adjacent counties where there were fewer than 100 wells drilled.
The study, Marcellus Shale Drilling’s Impact on the Dairy Industry in Pennsylvania: A Descriptive Report, by Madelon Finkel et al, references two earlier studies into animal health and unconventional gas drilling.
Another recently completed study investigating changes in milk production and cow numbers in Pennsylvania counties between 2007 and 2010 found an association between drilling and declining cow numbers, with higher drilling activity associated with larger average declines in cow numbers. Further, counties with 150 or more Marcellus Shale wells on average experienced an 18.5 percent decrease in total milk production compared to an average increase of 0.9 percent in counties with no Marcellus Shale wells drilled. While the study could not fully explain the findings, the implications for Pennsylvania, with its large dairy industry, need to be more fully investigated.
This descriptive study seeks to lay the basis for observing trends in a longi- tudinal approach and to raise questions that can be tested in a more analytic manner. We focus on Pennsylvania primarily because there has been an explo- sive increase in unconventional drilling in this state since 2006 (unlike in neighboring New York, which as of 2012 has a moratorium on drilling in place), and because the implications for its agricultural and dairy industries could be significant.
The authors of the study say that more research is needed.
While this descriptive study cannot draw a causal association between well drilling and decline in cows or milk production, given the importance of Pennsylvania’s dairy industry and the projected increase in unconventional natural gas drilling, further research to prevent unintended economic and public health consequences is imperative.
Unconventional natural gas drilling in Pennsylvania has accelerated over the past five years, and is unlikely to abate soon. Dairy farming is a large component of Pennsylvania’s agricultural economy. This study compares milk production, number of cows, and production per cow in counties with significant unconventional drilling activity to that in neighboring counties with less unconventional drilling activity, from 1996 through 2011. Milk production and milk cows decreased in most counties since 1996, with larger decreases occurring from 2007 through 2011 (when unconventional drilling increased substantially) in five counties with the most wells drilled compared to six adjacent counties with fewer than 100 wells drilled. While this descriptive study cannot draw a causal association between well drilling and decline in cows or milk production, given the importance of Pennsylvania’s dairy industry and the projected increase in unconventional natural gas drilling, further research to prevent unintended economic and public health consequences is imperative.