EHP study recommends 1 to 2 kilometer setbacks

August 21, 2018

oil and gas drilling, setbacks

How close is too close? A subdivision in Erie, CO is surrounded by gas drilling. [Photo credit: Ted Wood/The Story Group]

A mountain of scientific evidence based on peer-reviewed studies has shown that living in close proximity to unconventional oil and gas development (UOGD) is associated with serious health risks.

For their newly published Delphi study, the Environmental Health Project (EHP) looked at the question: “How close is too close?”

The study, Setback distances for unconventional oil and gas development: Delphi study results was published last week at PLOS ONE.

A setback distance is the distance a shale gas facility is required by law to be from a structure or building. In Pennsylvania, as of 2018, setback distance is 500 feet for horizontally-drilled well pads from the well bore to the edge of an existing building, and 750 feet for compressor stations and processing plants. Allowances for the distance to be as little as 300 feet for well pads apply in residential districts if the 500 feet restriction cannot be met.

Based on the results of their study, EHP recommends increasing Pennsylvania’s current existing building setback distance to a minimum of 0.6 miles (3,281 feet or 1 km), and increasing the current setback for gas processing plants and large compressor complexes to a minimum of 1.25 miles (6,600 feet or 2 km).

Colorado regulations specify minimum setback requirements for oil and gas facilities at 350 feet for outdoor-activity areas like playgrounds, 500 feet for occupied buildings, and 1,000 feet for high-occupancy buildings like schools or hospitals. Those setbacks are measured from the center of the well to the buildings, not the property line.

In Colorado, Initiative 97 would mandate that new oil and gas development, including fracking, be a minimum distance of 2,500 feet from occupied buildings, as well as public parks, public open space, irrigation canals, lakes, rivers, perennial or intermittent streams and any additional vulnerable areas designated by the state or a local government. Initiative 97 is awaiting approval from Secretary of State Wayne Williams. If approved, the measure will appear on the November ballot.

For the EHP Delphi study, 18 panelists, including health care providers, public health practitioners, environmental advocates, and researchers/scientists, considered all aspects surrounding the issue of setbacks. Panelists looked at several studies including Dr. Lisa Mackenzie’s studies in Garfield County, Colorado. Three rounds were used to identify and seek consensus on recommended setback distances.

Round 1 questions revealed four categories:

  • recommend setback distances
  • do not recommend setback distances
  • recommend additional setback distances for vulnerable populations
  • do not recommend additional setback distances for vulnerable populations.

Round 2:  Panelists indicated their level of agreement with the statements in each category using a five-point Likert scale.

Round 3: Using emerging consensus from the first 2 rounds, statements within each category were collapsed into seven statements for recommend set back distances:

  • less than ¼ mile
  • ¼ to ½ mile
  • 1 to 1 ¼ mile
  • more than 2 mile
  • not feasible to recommend setback distances
  • recommend additional setbacks for vulnerable groups
  • not feasible to recommend additional setbacks for vulnerable groups.

The panel reached consensus that setbacks of less than ¼ mile should not be recommended and additional setbacks for vulnerable populations should be recommended. The panel did not reach consensus on recommendations for setbacks between ¼ and 2 miles.

The results suggest that setback distances should be greater than ¼ of a mile from human activity, and that additional setbacks should be used for schools, daycare centers, and hospitals where vulnerable groups are found. The lack of consensus on setback distances between 1/4 and 2 miles reflects the limited health and exposure studies and need to better define exposures and track health.

While appropriate setback distances are also important related to water sources and pipelines, they are not addressed in this study.

Shale gas facilities release emissions into the air. These emissions contain methane as well as toxic substances including formaldehyde, and volatile organic compounds (VOCs) such as benzene and toluene. Air currents carry the emissions away from facilities into surrounding communities.

In addition, methane is explosive. Accidents involving explosions have occurred at shale gas facilities including well pads, pipelines and compressor stations. In order to protect public health, setback distances need to be adjusted for facilities to address both emissions and explosion dangers.


Source: Marcellus Outreach Butler

Studies indicate that negative health effects increase the closer one is to shale gas facilities:

  • Negative birth outcomes from 0.6 to 1.8 miles of shale gas development including low birth weight (5.8 lbs and less), and higher rates of small-for-gestational-age (SGA).
  • Babies born to mothers living less than a mile from wells were 25 percent more likely to weigh less than 5.8 pounds at birth.
  • Increase in number of babies born with congenital heart disease and possibly neural tube defects is related to both the number of wells in the vicinity and the distance from them to the mother’s homes.
  • Worsening asthma symptoms are linked to nearness of shale gas facilities.
  • Self-reported symptoms, including headaches, fatigue, upper and lower respiratory complaints, skin rashes, and mental health concerns (anxiety and depression) are seen up to 5 miles from well pads.
  • Health symptoms reported by residents, such as headaches and wheezing, were more frequent the closer the resident lived to wells.

Low birth weight, small for gestational age, and preterm birth, listed above, should not be taken lightly. They may lead to serious future consequences in growth and development including: diabetes, heart disease, high blood pressure, intellectual and developmental disabilities, obesity, and death.

Stress, anxiety and other mental health symptoms also increase the closer one is to shale gas development. Residents have reported anxiety/stress/anger/depression related to air, water, noise, light pollution, current or existing health issues, and the possibility of having to move. More appropriate setback distances could reduce impacts of these factors.

In a 2016 EHP study, The Problem of Setback Distance for Unconventional Oil & Gas Development: An analysis of expert opinions, 89 percent of participants agreed that setbacks from shale gas infrastructure should not be less than ¼ mile [1320 feet]. Many participants felt that additional studies are required to accurately determine a safe setback distance, but a 1 to 1¼ mile setback distance received 50 percent support. The experts also agreed that greater setback distances should be considered for buildings that house vulnerable populations, such as schools, day care centers, and hospitals.

In 2014, the University of Maryland conducted a comprehensive study of the potential public health effects of shale gas development prior to the state’s ban on fracking: Potential Public Health Impacts of Natural Gas Development and Production in the Marcellus Shale in Western Maryland. Based on emissions and possible explosions at shale gas sites, the study recommends no less than a 2000 feet setback for well pads as well as compressor stations not using electric motors. When burning raw gas or gas that has not been processed, toxic emissions are higher.

A well explosion in Belmont County, Ohio, in February 2018, resulted in a 1 mile evacuation radius impacting 30 homes. The damaged well took 3 weeks to cap, releasing methane and related emissions into the air.
Return frack fluid also poured from the damaged well, threatening local waterways.

It is difficult to determine a safe setback for accidents involving explosions and fireballs. What can be observed, however, are evacuation zones from previous shale gas accidents. In Adequacy of Current State Setbacks for Directional High-Volume Hydraulic Fracturing in the Marcellus, Barnett, and Niobrara Shale Plays (M. Haley et al) of the incidences studied, the average evacuation zone was 0.8 miles or 4224 feet.

“Based on historical catastrophic events, thermal modeling, vapor cloud modeling, and air pollution data, these [setback] distances do not appear sufficient to protect public health and safety.”

Setbacks should account for the number of people to be evacuated, the time it would take to evacuate, and the route of evacuation.

These studies suggest that current setback distances fail to protect the public from both emissions of toxic air pollution and extreme heat due to a possible explosion from shale gas facilities. Additionally, these minimal setbacks do not take into account the time needed to evacuate high occupancy buildings (schools, hospitals, malls, etc.).

Based on the literature available today, it is reasonable that health effects from shale gas development occur more frequently the closer to the source. In addition, different shale gas infrastructure produces different volumes of emissions. For example, processing plants and compressor stations emit more frequently and in greater volume than do wells. This should be considered in determining setback distances.

Recommendations to Regulatory Agencies to Better Protect Public Health:

  • Establish a setback distance minimum of 0.6 mile (3281 feet or 1 km) from smaller shale gas facilities, such as wells, that emit 100 to 500 grams/hour.
  • Establish a setback distance minimum of 1 ¼ miles (6600 feet or 2 km) from gas processing plants and large compressor complexes whose emissions exceed 1000 grams/hour.
  • Establish a setback distance minimum of 1 ¼ miles (6600 feet or 2 km) for schools/daycares, hospitals, nursing homes, and other high-occupancy buildings that house vulnerable populations and/or are difficult to evacuate.


Setback distances for unconventional oil and gas development: Delphi study results

Hydraulic fracturing and infant health: New evidence from Pennsylvania

Final Report: Potential Public Health Impacts Of Natural Gas Development And Production In The Marcellus Shale In Western Maryland

XTO Well in Powhatan Point Capped After 20 Days

Birth Outcomes and Maternal Residential Proximity to Natural Gas Development in Rural Colorado

Proximity to Natural Gas Wells and Reported Health Status: Results of a Household Survey in Washington County, Pennsylvania

Adequacy of Current State Setbacks for Directional High-Volume Hydraulic Fracturing in the Marcellus, Barnett, and Niobrara Shale Plays

Drilling and Production Activity Related to Unconventional Gas Development and Severity of Preterm Birth

Association Between Unconventional Natural Gas Development in the Marcellus Shale and Asthma Exacerbations

Associations between Unconventional Natural Gas Development and Nasal and Sinus, Migraine Headache, and Fatigue Symptoms in Pennsylvania

Human exposure to unconventional natural gas development: A public health demonstration of periodic high exposure to chemical mixtures in ambient air

Health symptoms in residents living near shale gas activity: A retrospective record review from the Environmental Health Project

Public health implications of environmental noise associated with unconventional oil and gas development

Psychosocial implications of unconventional natural gas development: Quality of life in Ohio’s Guernsey and Noble Counties

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