One of the most-read posts on the blog is the disturbing story of the town of Vernal and the Uintah Basin in eastern Utah, where decades of oil and gas exploration have led to terrifying public health problems, and the prospects for the future are bleak.

One of the key points of that post, and others, is that there are many “unknown unknowns” — things we just don’t know yet about how oil and gas drilling affect the health of newborns, of residents over time, and of domestic and wild animals in the area.

Today we have some new knowledge about the Uintah Basin that begins to answer some of the questions about why these health impacts are taking place. The information comes from a study led by the Cooperative Institute for Research in Environmental Sciences (CIRES) that pinpoints the sources of airborne pollutants. CIRES is a joint institute of the University of Colorado Boulder and the National Oceanic and Atmospheric Administration. The study appears in the journal Atmospheric Chemistry and Physics.

Lead author Carsten Warneke, an atmospheric chemist with CIRES at the University of Colorado Boulder, explained the value of this information.

“Before you can stop a leak, you have to know where it is. This study tells us where the largest emissions are coming from, and that, in turn, helps industry identify what they can do to reduce emissions as cheaply and effectively as possible.”

Oil and gas production fields produce volatile organic compounds (VOCs) such as methane, toluene and benzene. Methane is a greenhouse gas that is a primary cause of global warming, toluene can harm the liver and kidneys, and benzene is a carcinogen. Oil and gas produce VOCs, and air pollution produced in oil and gas fields can damage the lungs.

The study shows that in the Uintah Basin, equipment located on well pads—such as condensate tanks, dehydrators, and pumps—are key sources of pollutants. It also found that well operations frequently emit high levels of benzene and toluene, and that emissions vary by production method.

Key findings

1. On well pads, some equipment leaks more VOCs than others. The main emitters include separators, dehydrators, and oil and natural gas liquid (condensate) tanks. Separators divide natural gas into its liquid and gas fractions, and dehydrators remove water from natural gas.
   

   Photo credit: CIRES

2. Different production techniques result in different emissions. For example, dehydrating gas on-site (at the well pad) leads to higher emissions of VOCs than dehydration carried out off-site at a centralized facility.
3. The scientists found high ambient levels of benzene and toluene (another air toxic) at specific sites in the basin, with measurements reaching up to 1,000 parts per billion (1 part per million) by volume. “In urban areas, values are closer to 0.1 to 0.2 parts per billion by volume,” Warneke said. One such site was a recently re-fractured well with a flow-back pond. Evaporation ponds were also a large source of VOCs.
   

   Photo credit: CIRES

4. In Rangely, Colorado, where the team also took measurements, they found fewer emissions, probably because of two key factors: Rangely’s gas field is drier than Uintah Basin’s, and most wells have electric power. Both factors lessen the need for production equipment, such as dehydrators and storage tanks. “Less equipment means fewer opportunities for leaks
   

   Photo credit: CIRE

What it means for us
This study shows how we are slowly beginning to learn what we don’t know about the long-term impacts of oil and gas drilling on our communities. The data shows that certain types of equipment, certain climates, and certain production techniques reduce emission levels. As we learn we have an opportunity to develop best practices that will minimize the adverse impacts of drilling.

However, this learning process will likely take decades. In the meantime more communities will suffer the devastating results seen in Vernal, Utah.

What we need to do now is demand protection  by requiring the highest and best management practices in oil and gas drilling. If we don’t, the unknown unknowns will come back to hurt us now and in years to come.

This is a key reason behind our push for citizen initiated zoning. If you have the opportunity to sign up, be sure to do it. As citizens and land owners we must establish critical protections now.