“The OEHHA chronic benzene REL considers several studies published after USEPA’s 2002 benzene assessment, which found increased efficiency of benzene metabolism at low doses, decreased peripheral blood cell counts at low doses (800−1860 μg/m3)…”

It takes another 20 words — with terms like “metabolic enzymes” and “benzene detoxification” — to close out this sentence from a recent University of Colorado study that looked at the potential health impacts of Front Range oil and gas operations. Thousands of equally abstruse passages fill hundreds of other studies from around the world examining the effects of drilling and hydraulic fracturing on human health.

Welcome to the science behind Proposition 112, the oil and gas setbacks measure that will likely be among the most complex ballot issues to ever go before Colorado voters.

The initiative aims to increase the required distance of any newly drilled wells from homes, schools and water sources to 2,500 feet. The current setback is 500 feet from homes and 1,000 feet from densely occupied buildings, like hospitals and schools.

Opponents say the measure will block off so much acreage to drill rigs — it’s estimated that 85 percent of non-federal land in Colorado would be off-limits — that the $31 billion industry in Colorado would virtually collapse. Backers of 112 say without bigger buffers, Coloradans will continue to be exposed to noxious emissions from well sites, like toluene, formaldehyde, xylene, and cancer-causing benzene, to say nothing of the environmental harm from potent greenhouse gases, like methane.

What is the average voter supposed to do with the reams of data, some in conflict with one another, in deciding whether Proposition 112 is critical to public health or ruinous to Colorado’s economy?

“It’s hard when we ask voters to vote on technical issues like this,” said Tanya Heikkila, a professor at CU Denver’s School of Public Affairs who focuses on environmental policy, management and law.

She said few voters have the time, patience or expertise to navigate through the copious scientific research that has been done on energy extraction. As such, she said, they’ll likely turn to the people they know for advice on which box to check on the ballot — their friends, their neighbors, their doctor.

“I don’t think people’s decision on this will come down to what the science says — it will come down to who they trust,” Heikkila said.

It’s also likely, she said, that voters will employ “motivated reasoning” or be swayed by “confirmation bias” to make their choice on Proposition 112.

“Cognitive research has shown that when people are emotionally attached to an issue, it’s easier to reason away or dismiss the information that contradicts those beliefs — or conversely use information that supports their beliefs to confirm those beliefs,” Heikkila said.

Arguments from each camp are compelling, she said, and voters may find virtue on both sides of the issue.

“No one wants to be exposed to carcinogens, to noise, to (truck) traffic,” she said. “At the same time, when people say 112 is going to cost them their jobs and ruin the tax base, that resonates too.”

“Something is happening here”

Anne Lee Foster, who is with the pro-112 group Colorado Rising, knows she can’t fight the oil and gas industry on the financial front. As of the most recent reporting period from late September, the anti-112 group Protect Colorado had dropped just over $20 million on its battle against the measure, while Colorado Rising had spent less than $650,000.

Foster hopes science speaks louder than cash. She and her allies point to a compendium of studies — now numbering more than 1,300 — that are assembled and updated on the Physicians for Social Responsibility website. The studies have examined one aspect or another of fracking’s harms and risks, pointing out connections to cancer, low birth-weight babies, asthma, headaches and bloody noses for families living near oil and gas wells.

Fracking involves injecting at high pressure a mixture of water, sand and chemicals into a well to fracture rock and allow minerals trapped underground to flow back out. An assortment of toxic and combustible gases and compounds often rise to the surface as well.

The danger of oil and gas activity close to neighborhoods was thrown into stark relief last year, when a leaking flowline filled the basement of a home in Firestone with gas. The gas ignited and exploded, killing two men and injuring a woman. Scrutiny of Colorado’s oil and gas sector has picked up in the last few years as production has ramped up, much of it near fast-growing communities north of Denver.

The state produced 132 million barrels of oil last year — four times its 2010 volume. There were more than 55,000 producing wells in Colorado as of the end of 2017, according to the Colorado Oil and Gas Conservation Commission, with nearly half located in Weld County.

The COGCC has received more than 2,200 complaints from residents between January 2015 and May of this year regarding oil and gas activity, ranging from odor to air quality to noise to flaring.

“Something is happening here,” Foster said. “This is about health and safety — this is about keeping an explosive industry away from our homes and keeping benzene away from our playgrounds and children.”

But exactly what the health hazards are — and more specifically what distance from wells is required to avoid them — is the confounding question at the heart of Proposition 112.

“No bright line”

In April, the former head of the Colorado Department of Public Health and Environment criticized a CU study that found that those living just outside the 500-foot oil and gas buffer faced an increased risk of developing cancer. Then-CDPHE Executive Director Dr. Larry Wolk said the study’s data conflicted with the state’s own monitoring, which hasn’t detected worrying levels of benzene or other chemicals. He called for further study.

John Adgate, a professor in the Department of Environmental and Occupational Health at the Colorado School of Public Health, said one of the big challenges in the field is trying to pinpoint the source of pollution. How much is the oil and gas industry to blame, as opposed to other sources like highways or emissions from industrial activity wafting in from other states, he asked.

Add in topography, weather conditions, the size of the well pad, and people’s lifestyles and genetic predispositions — and determining an optimum setback distance that protects public health is a tough call.

“There is no bright line between safe and unsafe,” Adgate said. “It’s hard to do the causal attribution the public would like to see.”

Even the CDPHE, which released a report in 2017 that found “the risk of harmful health effects is low for residents living near oil and gas operations,” noted there is a need for more research.

The agency analyzed 10,000 air samples for 62 substances associated with oil and gas activity and estimated that for those living just outside a 500-foot buffer from a well pad, exposure to those substances was in a safe range. However, the agency suggested levels of hazardous benzene, formaldehyde and acetaldehyde “are a high priority for continued monitoring.”

“We couldn’t conclusively say there were no problems from the existing data, but we didn’t find anything that was elevated risk from that data,” said Tami McMullin, state toxicologist with CDPHE.

Colorado Oil and Gas Association President and CEO Dan Haley criticizes the proposed 2,500-foot setback as arbitrary and unscientific.

“I have seen no credible science that indicates that the current setback distances need to be increased,” he said.

The fact that Proposition 112 would place so much of Colorado’s land surface off limits to new drilling, Haley said, means companies would likely pick up and leave the state. The Colorado Legislative Council calculated that a 2,500-foot buffer would designate 450 acres surrounding a protected point as a no-drill zone; under a 500-foot setback, 18 acres is off-limits.

A study from a local business consortium that 112 opponents often cite calculated that the greater setback would jettison up to 147,800 jobs in Colorado by 2030 and slash state and local tax revenues from oil and gas activity by up to $258 million in 2019 alone.

Both candidates for governor have come out against Proposition 112, as has Gov. John Hickenlooper.

“We can have a healthy economy and a healthy environment,” Haley said. “We can and we do.”

The precautionary principle

But if there’s even a modicum of doubt about how volatile organic compounds and other pollutants associated with fracking are affecting people living nearby, why not err on the side of safety? That’s the question that Sandra Steingraber, a biologist with the Concerned Health Professionals of New York, asks.

“The science of public health errs on the side of protecting people,” Steingraber said. “It comes down to how you want to look at uncertainty and the burden of proof.”

The precautionary principle was invoked by Howard A. Zucker, acting state health commissioner for New York, when that state banned fracking five years ago.

“We cannot afford to make a mistake,” Zucker said in December 2014, as reported by The New York Times. “The potential risks are too great. In fact, they are not even fully known.”

Steingraber said the resistance to larger setbacks for oil and gas wells reminds her of the early opposition that was mounted by industry when it came to acknowledging the hazards of lead paint or secondhand smoke.

As it stands, the science — both in quality and volume — is firmly on the side of those pushing for Proposition 112, Steingraber said. She criticized the 2017 CDPHE study for a lack of rigor, saying it didn’t consider local geography or weather events and didn’t feature continuous monitoring, meaning any “conclusions about short-term impacts will be invalid.”

If recent fires and leaks at oil and gas facilities on the Front Range are any indication of the sudden and severe danger a highly industrialized facility like an oil and gas pad can pose, many say caution is the recommended course of action.

A Denver Post review of state records found that at least a dozen explosions and fires occurred along Colorado oil and gas industry pipelines in the eight months after the April 2017 Firestone tragedy. Two of those explosions killed workers.

Less than half a year following Firestone, a crowd at a football game in Greeley had to be evacuated after an equipment failure on a compressor resulted in a high-pressure gas leak. Last November, state regulators cited Denver-based Crestone Peak Resources after workers improperly vented volatile organic compounds at a well pad next to Aspen Ridge Preparatory School in Erie.

“We found leaks and contamination at every step of the process,” Steingraber said of oil and gas sites across the globe. “If you have bigger setbacks, you’ll save lives.”

Fracking: The “f-word”

How big matters to Mike Eberhard, chief operations officer for SRC Energy. The company’s 8-acre fracking site, known as the Greeley Rothe pad, has nearly 40 employees and contractors working there on any given day. The drilling of 12 wells began in the summer and fracking those wells will continue through the rest of 2018.

He said the pad, which features horizontal wells that extend two miles underground toward downtown Greeley, wouldn’t have been allowed under Proposition 112’s 2,500-foot setback.

Colorado has some of the strictest regulations on the industry, Eberhard said, but even so fracking has become the “f-word” in the larger conversation about energy development — politicized to the point where no matter what environmental controls are put in place by oil and gas operators, it won’t satisfy the anti-drilling contingent.

“Hydraulic fracturing has become a synonym for so much,” he said.

The improvements the industry have made in the last few years are substantial, Eberhard said. At the Greeley Rothe pad, he pointed to sound walls with lights mounted inside the walls, an arrangement designed to cut down on noise and light pollution. SRC uses a Sandbox system to deliver sand to the site, which greatly reduces the amount of particulates escaping and blowing off site, he said.

The pad also has water piped in off site, which sharply reduces truck traffic and accompanying emissions across Weld County, Eberhard said.

The industry points to its use of pollution-reduction technology, like methane capture, leak detection cameras and remote monitoring equipment, for helping make drilling and fracking a cleaner process than it once was.

“These are some of the things we’ve done to minimize impacts,” Eberhard said. “We take it very seriously. We live here.”

But claims of improved operations at Colorado’s oil and gas sites are of little solace to those who feel like they are under siege in their own homes, suffering from unexplained health ailments.

Stacy Lambright, who lives near a producing well pad in her North Creek Farms neighborhood in Thornton, said she and her children began experiencing nose bleeds and headaches right around the time a subcontractor found a leaking flow line at the site nearly three years ago.

That discovery triggered a remediation effort that resulted in the excavation and treatment of 3,500 cubic yards of soil and the removal of 3,000 barrels of groundwater, which contained elevated levels of benzene. A children’s playground sits just a few hundred feet away from the well pad.

“We are guinea pigs,” Lambright said. “I really think in so many years from now we’ll look back at this and say we were wrong. There are too many unknowns.”

Susan Noble, a Commerce City resident, says energy companies are seeking permits for nearly 200 wells at multiple well pads within just a mile or two of her Reunion neighborhood.

“Parents are especially concerned about their children’s and future children’s health — kids are most susceptible to the VOC emissions from these sites — and are talking about moving away,” she said. “Heavy petrochemical activity doesn’t belong near or in residential areas.”

Just a year ago, state regulators were putting pressure on the industry for more controls to cut Front Range air pollution and smog. Ozone levels in the metro area haven’t met limits set by the federal government in years.

“A political mistake”

Pat Quinn, Broomfield’s former mayor who served on the state’s 19-member oil and gas task force a few years ago, is no fan of Proposition 112. At the same time, Quinn thinks a 500-foot setback is insufficient.

That’s largely because today’s well pads can have up to 30 or more wells, he said. While the multi-well approach limits impacts to the land surface, it boosts industrial activity at a well pad to a much more intense level.

“Once you’re 500 feet away, they are practically in your backyard,” said Quinn, who has worked for the oil and gas industry as an accountant. “I don’t believe that even the industry believes 500 feet is acceptable for a 40-well pad.”

Broomfield established a 1,320-foot buffer — one-quarter mile — that oil and gas firms are asked to comply with if they want to drill in the city. It’s a compromise that addresses the desires of both sides in the debate, he said.

“Had the industry addressed this issue five years ago when they started coming into these urban and suburban areas — letting local governments have a say about where the locations would be — it would have taken the pressure off of the industry,” Quinn said. “It was a political mistake.”

COGA’s Haley admits that the industry didn’t do a good job in the last few years of communicating with homeowners and city officials when it came to the issue of compatibility of drilling and fracking with fast-growing communities. But he said Proposition 112 is not the answer.

“What I know doesn’t work is inserting blunt instruments into state law that don’t allow for dialogue, waivers or nuance,” he said. “COGCC is a better place to address this issue than the ballot box.”