A new study from researchers at the Colorado School of Public Health suggests that living near oil and gas operations could result in exposure to dangerously high levels of carcinogens — and that current state regulations aren’t sufficient to protect public health.

According to the study, which looked at families living near oil and gas wells in Colorado’s Northern Front Range, the lifetime cancer risk of living within 500 feet of a well was eight times higher than the highest level of risk allowed by the Environmental Protection Agency (EPA).

The study looked at 500 feet, specifically, because Colorado law requires that new oil and gas wells be built at least 500 feet from homes. According to FracTracker, there were more than 60,000 active oil and gas wells in Colorado as of May 2017. It’s unclear how many wells are within 500 feet of homes, though an analysis by Inside Energy found that since 2013, 220 new wells have been built within 500 feet of homes in Colorado’s Northern Front Range.

Living near oil and gas operations comes with a host of concerns, from nuisance noise to the danger of an explosion. But the Colorado School of Public Health Study — published in the journal Environmental Science and Technology — looked specifically at air quality near oil and gas operations, and found high levels of carcinogenic compounds like benzene, which has been linked to certain kinds of cancers, like leukemia.


“The highest concentrations of hazardous air pollutants were measured in samples collected nearest to an oil and gas facility,” Lisa McKenzie, an assistant research professor in the Environmental and Occupational Health department at Colorado School of Public Health and the study’s lead author, said in a press statement. “For example, average benzene concentrations were 41 times higher in samples collected within 500 feet of an oil and gas facility than in samples collected more than a mile away.”

Colorado, which produced 9.1 million barrels of crude oil in 2016, requires oil and gas operations to be at least 500 feet from homes, and 1,000 feet from high-occupancy buildings like schools.

But the study from the Colorado School of Public Health suggests that those standards might not be strong enough to protect the public from potentially adverse health impacts associated with diminished air quality around oil and gas operations — a finding that could have serious policy implications for a state that has continued to see oil production expand as prices remain low.

“Our previous work shows that thousands of people along the Front Range of Colorado live closer than 500 feet from a well and related infrastructure and that the population living close to these facilities continues to grow,” MacKenzie said.


A previous study, published last year by the Colorado Department of Public Health and Environment, did not find strong evidence linking proximity to oil and gas wells with health risks. Other studies, however, have linked living close to oil and gas operations with adverse health impacts.

One study, which looked at health impacts near fracking operations in Pennsylvania, found that 39 percent of those living less than 0.6 miles from a gas well reported upper-respiratory problems, compared with just 18 percent of those living more than 1.2 miles away.

Another study, which looked at more than 1.1 million births in Pennsylvania, found that babies born to mothers who lived within 0.6 miles of an oil or gas well weighed, on average, 1.38 ounces less than babies born to mothers who lived 1.8 miles or more from wells.

The distance that an oil or gas operation can be placed with respect to a home — known as a setback — has been the topic of political debate both in Colorado and in oil and gas producing states around the country.

In 2016, oil and gas operators spent more than $15 million to defeat a pair of ballot initiatives in Colorado that would have moved the setback limit from 500 feet to 2,500 feet.


And the setback isn’t an ironclad rule — homes can be built closer than 500 feet to an oil or gas well, and operators can ask for permission to drill within 500 feet of homes. In Greeley, Colorado, for instance, residents are currently fighting a proposal by a Denver-based oil and gas company to construct a well within 500 feet of a local school’s playground.

Across the country, there is little consistency from state to state with respect to setback requirements.

Los Angeles County, which is home to the largest urban oil field in the country, has a setback requirement of just 300 feet, though the Los Angeles City Council has considered expanding that to 2,500 feet. In Oklahoma, there is no statewide requirement for how far oil and gas wells need to be from homes and schools, leaving cities responsible for determining whether or not to restrict oil and gas wells from being drilled near homes.

In Texas, oil and gas wells must be at least 200 feet from a private residence, though oil companies are allowed to apply for an exemption if they want to drill closer. In Pennsylvania, oil and gas operations are required to be setback 500 feet from buildings, but again, oil companies are allowed to apply for exemptions.

Because setback requirements are often the result of political compromises rather than scientific understanding of the risks of living near oil and gas operations or historical modeling of potential dangers, a 2016 study that looked at the efficacy of setback requirements in Colorado, Pennsylvania, and Texas found that “current natural gas well setbacks in the Barnett Shale of Texas, the Marcellus Shale of Pennsylvania, and the Niobrara Shale of Colorado cannot be considered sufficient in all cases to protect public health and safety.”