Fracking Risk Assessment - Letter to the Arapahoe County Commissioners
April 4, 2025
Dear County Commissioners,
I am writing on behalf of Colorado Physicians for Social Responsibility (PSR Colorado), an organization guided by the values and expertise of medicine and public health, and dedicated to protecting present and future generations from the negative health impacts of hydraulic fracturing, the climate crisis and exposures to radionuclides and other toxic substances.
We have followed the progression of continued growth and permitting for oil and gas development while tracking the growing body of epidemiological studies that have documented elevated occurrence ofhealth harms, including birth defects, childhood cancers, and other short term and chronic impacts in people living in close proximity to this development as compared with those living a greater distance from production facilities.
As a PSR Colorado Advisory Council member, I recently met with community organizers who have been actively opposing hydraulic fracturing in Adams and Arapahoe Counties for several years. Presently, they are concerned about the upcoming decision by Arapahoe County on the Sunlight-Long well pad. Dr. Mckenzie's second and most recent study that links childhood leukemia to proximity to oil and gas wells has again raised concerns about impacts on children in particular.
We are also concerned, particularly, by how this evidence is being consistently dismissed by public agencies at the state and local level.
At an August 2, 2024 ECMC hearing last year, the 2019 CDPHE/ICF risk assessment was used as evidence of no harm. And the ECMC, in part, based their approval of the Lowry Ranch CAP on this.
That risk assessment was based on a study of emissions from oil and gas operations in Weld and Garfield counties conducted by Colorado State University. ICF International, the authors of the risk assessment, stated that "CSU researchers worked with several industry partners to identify sites suitable for conducting the studies."
While we do not currently question the methodology used in the risk assessment, it appears that this CSU study did not include a random sample but rather a potentially biased sample. The CSU study was also funded in part by numerous oil and gas companies.
At the August 2, 2024 hearing, Dr. McMullen, an ICF epidemiologist stated that "based upon all the scientific evidence and all the data that have been collected by multiple agencies across Colorado when you look at the evidence there's not an evidence that there's been health risks to people actually even as close as probably less than 500 feet. I've conducted thousands of studies I mean and collected data around Civitas and Creststone well pads probably for over five years and I'll tell you we've even collected samples as close as 100 feet to their well pads where we have not seen adverse health impacts related to air quality that would be at levels of concern to cause health impacts.”
Dr. McMullen dismissed the findings of the many epidemiology studies that found statistically significant association between risks of certain conditions and density and proximity of wells within well distances of up to and beyond 8 miles. These epidemiological studies, many of which were conducted at our own Colorado School of Public Health and published in peer reviewed journals, are being dismissed as being only "associative"by the agencies and individuals charged with protecting the public interest..
Epidemiological studies that are “associative” have been held in high regard. They are the basis upon which cigarette smoking was linked to lung cancer. The June 2024, California Oil and Gas Public Health Rulemaking Scientific Advisory Panel report Public Health Dimensions of Upstream Oil and Gas Development in California: Scientific Analysis and Synthesis to Inform Science-Policy Decision Making concluded that the "epidemiologic evidence indicates that close residential proximity to OGD is associated with adverse perinatal and respiratory outcomes" and that "the setback distance should be at least 1 km (3,281 ft). In communities with higher well density, high hydrocarbon production volumes, dense ancillary oil and gas development infrastructure, and the presence of other environmental hazards and socioeconomic stressors, a larger setback should be applied."
We believe that the CDPHE and other agencies have an ethical responsibility to take into account evidence from epidemiological studies in their decision-making process. We also question whether the study sample chosen in cooperation with operators compromises the validity of the study and hence the risk assessment.
We ask that the evidence from dozens of epidemiological studies be taken into account when Arapahoe County makes this very important decision.
Barbara Donachy, MPH
PSR Colorado Advisory Council
