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Air Quality Impacts from Oil and Gas
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Air Quality Impacts from Oil and Gas

Boulder County as a whole is very active in addressing the impacts from existing and new oil and gas development, including impacts to air quality and public health.

Boulder County Public Health has specifically undertaken and supported studies and analyses to understand the potentially hazardous impacts of oil and gas development on public health, safety, and the environment. Public Health is also involved in local and state-level oil and gas emissions regulatory processes in the interest of preserving public health.

Current News

Since 2017, Boulder County has funded an air quality monitoring study at the Boulder Reservoir. Monitoring tracks the presence of compounds such as nitrogen oxides, methane, ethane, propane, pentanes, and benzene and provides near real-time measurements of their concentrations. Go to Boulder A.I.R’s website to see this data. See “Current Studies” below for more information.

Boulder County has been actively involved in a series of oil and gas rulemakings before Colorado’s Air Quality Control Commission and works collaboratively with many local governments from across the state who are all seeking to reduce pollution and improve air quality and climate impacts.


Local oil and gas production has more than doubled since 2000 with more likely to come. The Denver Metro area has exceeded the National Ambient Air Quality Standard for ozone since 2004. Ozone forms in the atmosphere through a series of chemical reactions involving volatile organic compounds (VOC) and nitrogen oxides (NOx). Despite efforts to regulate ozone pollution, levels in Denver and the Front Range are often above national health standards. Boulder County’s air quality is complex because it is located where the following meet:

  • The heavily urbanized City of Denver
  • Weld County oil and gas development
  • The rural wilderness of the Rocky Mountains

Downtown Boulder, with its dense vehicle traffic, has elevated levels of air pollution common to vehicle exhaust. In Longmont, locations near oil and gas development have shown elevated levels of pollutants found in gasoline vapor and natural gas condensate.

Monitoring helps us to better manage and reduce air pollution.

Boulder County is concerned about the impact of oil and gas on ozone pollution in our area.

  • The state of Colorado’s ozone monitor, located at the Boulder Reservoir, often records ozone readings in excess of the federal ozone standards.
  • Air quality analyses show that oil and gas development is often the largest contributor to high ozone levels in Boulder County.


Benzene is a hazardous air pollutant (HAP) that is regulated by the U.S. Environmental Protection Agency (EPA) under the Clean Air Act (CAA). Sources of benzene include motor vehicle exhaust; vapors from oil and gas production activities and gas stations; emissions from the burning of oil, coal, wood, and cigarettes; and household products containing petroleum‐based chemicals (e.g. glue, paint, furniture wax, and lubricants). Boulder County Public Health’s fact sheet on benzene on benzene includes information on health impacts, health standards for benzene, and monitored levels of benzene in Boulder County and around the state. Data from the County-funded monitoring study at the Boulder Reservoir show that benzene levels at that site are in the low range for health standards.

Research Findings

Boulder County Public Health has put together a brief overview of recent studies related to oil and gas and public health that are locally relevant.

A 2017 study reviewed air samples collected across Colorado’s Northern Front Range. The study found:

  • An elevated health risk for residents in proximity to oil and gas development.
  • The lifetime cancer risk for people living within 500 feet of an oil and gas facility is eight times higher than the Environmental Protection Agency’s upper risk threshold (8.3 per 10,000 vs 1 per 10,000 population respectively).

A 2014 Boulder County Air Quality Monitoring Study gathered data to quantify methane, ozone, and volatile organic compound (VOC) levels and to field test two new measurement devices (OG Pods) alongside traditional devices (summa canisters). The study found:

  • Oil and gas emissions were higher along the eastern portion of the county.
  • Promising results from OG Pods as an alternative measurement device.

2008: Understanding Air Toxics and Carbonyl Pollutant Sources in Boulder County, Colorado. This study, funded by the EPA and completed in partnership with University of Colorado, Boulder, used air quality monitors to provide a baseline to assess changes in emissions of air toxics over time. This study found that vehicles are an important contributor to air toxics in the urban and suburban portions of the County, and also found that the monitoring sites closest to oil and gas development had higher levels of compounds found in gasoline vapor and natural gas condensate.

Current Studies

Air Quality Monitoring Study

  • Boulder County Public Health is collaborating with atmospheric researchers (and in partnership with the Colorado Department of Public Health and the Environment (CDPHE)) to monitor concentrations of gases at the Boulder Reservoir. View air quality monitoring data and a summary of the current air quality study findings.
    • Monitoring tracks the presence of compounds such as nitrogen oxides, methane, ethane, propane, pentanes, and benzene and provides near real-time measurements of their concentrations.
    • An air quality modeling analysis of the monitoring data is being conducted and results will be available in 2021.
    • Atmospheric monitoring at Boulder Reservoir helps Boulder County officials to understand more about how oil and gas emissions are affecting ozone levels. It also provides a baseline against which to measure potential increases in future local and regional oil and gas emissions.

Leak Inspection & Repair at Existing Oil & Gas Facilities

Public concern has grown in Boulder County regarding the health and safety implications of emissions from oil and gas activity. Boulder County has implemented a voluntary oil and gas inspection program in order to respond to this concern. Inspections have collected data on gaseous leaks and repairs since 2014, and an analysis of this data is now available:

State and Local Regulations

Boulder County Public Health is actively engaged in task forces and regulatory processes within the County and at the state level, including providing testimony and comments to the Colorado Air Quality Control Commission and the Regional Air Quality Council to ensure the protection of public health and the environment.

Boulder County Oil and Gas Development Regulations

  • In March of 2017, the County Commissioners adopted the strongest set of oil and gas development regulations in the state of Colorado. See Article 12 of the Boulder County Land Use Code – Special Review For Oil and Gas Operations. The regulations will apply to new oil and gas development and substantial modifications to existing operations (such as the addition of new wells on an existing pad or refracking of an existing well).
  • Public Health provides ongoing expertise and support for County review of work at existing facilities.

State Level Regulatory Efforts

  • 2014: Participated in Regulation 7 rulemaking at the Colorado Department of Public Health and Environment. As part of a Local Government Coalition, Boulder County Public Health helped to achieve greater emission controls and established leak detection and repair programs statewide for oil and gas production facilities.
  • 2016: As part of a Local Government Coalition, presented initial findings from its oil and gas inspection program to the Air Quality Control Commission. The Local Government Coalition, along with environmental groups, advocated for an open stakeholder process for the October 2017 EPA Control Technique Guidelines for oil and gas emissions.
  • 2017: Participated in the 7-month stakeholder process with the Air Quality Control Commission, environmental groups, local governments, and the oil and gas industry.
  • August 2017: Along with the City and County of Denver, became a party to the Regulation 7 rulemaking at the Colorado Department of Public Health and Environment. And published a white paper that discussed the findings of the Voluntary Oil and Gas Inspection Program and presented it on the record for the rulemaking.
  • October 2017: Participated as part of the Local Government Coalition to increase the frequency of leak detection and repair inspections and the inclusion of pneumatic controllers in inspections. As a result, Colorado’s Regulation 7 was updated in December 2017.

Other State Level Efforts to Control Emissions

  • On-going: Participating in the Air Quality Control Commission’s Pneumatic Controller Task Force, attempting to better understand the impacts associated with emissions from malfunctioning pneumatic controllers used at production facilities and identifying the potential for alternative approaches.
  • On-going: Participating in the Statewide Hydrocarbon Emission Reduction (SHER) Task Force to establish new voluntary and regulatory methods to reduce hydrocarbon emissions statewide.

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Air Quality Program

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