Air pollution from Pennsylvania shale gas compressor stations is a significant, worsening public health concern.

By Cynthia Walter, Ph.D.

Dr. Walter is a retired biology professor who has worked on shale gas industry pollution since 2009 through Westmoreland Marcellus Citizens Group, Protect PT and other groups. Contact: walter.atherton@gmail.com

Executive Summary

Compressor Stations (CS) in the gas industry are sources of serious air pollutants known to harm humans and the environment. CS are permanent facilities required to transport gases from wells to major pipelines and along pipelines. Additional operations and equipment located at CS also emit toxins. In the last 20 years, CS abundance and sizes have dramatically increased in shale gas extraction areas across the US. This report will focus on CS in and near Southwestern Pennsylvania. Numbers of CS there have risen more than tenfold in the last decade in response to well completions and pipelines after the local fracking boom began in 2005. For example, Westmoreland County, Pennsylvania, had two CS before 2005 and now has 50 CS corresponding with about 341 active shale gas wells. In Pennsylvania, state regulations allow CS to be as close as 750 feet from homes, schools, and businesses. Emission monitoring relevant to public health exposure is limited or absent.

Current Pennsylvania policies allow rapid CS expansion. Also, regulations do not address public health risks due to several major flaws. First, permits allow annual totals of emitted toxins using models that assume constant releases, but substantial emissions from CS occur in peaks that expose citizens to concentrations may impair health, ranging from asthma to cancer. Second, permits do not address the fact that CS simultaneously release many serious air toxins including benzene and formaldehyde, and particulates that carry toxins into lungs. This allowance of multiple toxin release does not reflect the well-established science that public health risks multiply when people are exposed to several toxins at once. Third, permit reviews rarely consider nearby known air pollution sources contributing to aggregate air toxin exposures that occur in bursts and continually. Fourth, permits do not require operators to provide public access to real-time reports of air pollutants released by CS and ambient air quality near CS.

Poor air quality causes harm directly, e.g. respiratory distress, and indirectly, e.g., through increased vulnerability to respiratory viruses. The annual cost of damages from air pollution from CS was estimated at $4 million-$24 million in Pennsylvania based on emissions from CS in 2011. These damages include harm to human and livestock health and losses of crops and timber. After 2011, CS and gas infrastructures continue to expand, with increasing air pollution and damages, especially in shale gas areas. These costs must be compared to the benefits of using alternative energy sources. For example, in a neighboring state, New York, shifting to renewable energy will save tens of billions of dollars annually in air pollution costs, prevent thousands of premature deaths each year, and trigger substantial job creation, based on peer-reviewed research using US government data.

Table of Contents

Chemistry of Compressor Station Emissions

Health Effects of Compressor Station Emissions

Regional Air Toxins and Cancer Risk in Southwestern Pennsylvania

Measurements of Compressor Station Emissions

Compressor Station Locations

Costs of Compressor Stations and Air Pollution

Appendix – Compressor Station Locations in Westmoreland County, Pennsylvania

Chemistry of Compressor Station Emissions

CS emissions contribute major air pollutants to the total pollution from unconventional gas development (UCGD), but their role in regional air quality problems has not always been noted. In 2009, when UCGD operations were only a few years in this region and many CS had not yet been built, CS emissions were estimated to be a small component. Now, in 2020, gas transport requirements have increased, leading to many more and larger CS. The amounts of CS emissions have increased accordingly, based on estimates by Carnegie Mellon University atmospheric researcher, Robinson (Figure 1). Part of the reason that CS are such a major pollution source is that they run constantly, in contrast to machinery for well development and trucking that fluctuate with the market for new wells.

Figure 1. Relative contribution of compressor stations and other components of shale gas industry to Nitrous Oxides (NOx) and Volatile Organic Compounds (VOC). Source: Clean Air Council- adapted from webinar by Alan Robinson.

 

Air pollutants in CS emissions vary substantially in chemistry and concentrations due to differences in equipment (Table 1). Emissions in CS can come from several types of sources described below.

1. Engines: Compression engines powered with methane release nitrogen oxides (NOx), carbon monoxide (CO), volatile organic compounds (VOCs) and hazardous air pollutants (HAP). Diesel engines release those pollutants as well as sulfur dioxide (SO₂) and substantial particulate matter. In addition, diesel storage on site is a hazard. Electric engines produce less pollutants, but they are much less common than fossil fuel engines in southwestern Pennsylvania. CS operators can vary the use of engines at a station, and therefore, emissions vary during partial or full shutdowns and start-up periods.
2. Blowdowns: Toxic emissions dramatically increase during blowdowns, a procedure that is scheduled or used as needed to release the build-up of gases. Blowdown frequency and emissions vary with the rate of gas transport and the chemistry of transported gases. The full extent of emissions from any CS, therefore, is not known. Blowdowns can release a wide range of substances, and when flaring is used to burn off gases, the combustion creates new substances and additional particulates. Blowdowns are the most likely source of peaks in emissions at continuously operated CS. For example, Brown et al. (2015) used PA DEP measures of a CS in Washington County, Pennsylvania, alongside likely blowdown frequencies and weather models to predict peak emission frequency. They estimated nearby residents would experience over 118 peak emissions per year.
3. Non-compression Procedures: CS facilities are often the location for equipment that separate gases, remove water and other fluids, and run pipeline testing operations called pigging. These activities can be constant or intermittent and release a wide range of substances which may or may not be included in estimates for a permit. In addition, some of the processing releases gases which are flared at the facility, thus releasing a range of combustion by-products and particulate pollution. For example, the Shamrock CS operated by Dominion Transfer Inc. includes equipment for dehydration, glycol processing and pigging. The Janus facility operated by EQT includes dehydration and flaring. Permitted emissions for those facilities are listed in Table 1.
4. Storage Tank Emissions: CS often include storage tanks that hold substances known to release fumes. For example, the Shamrock CS was permitted to have an above ground storage tank of 3000 gallons for drip gas and a 1000-gallon tank for used oil, both of which release volatile organic compounds. The EQT Janus CS has two 8,820-gallon tanks. Gas releases from such tanks could be controlled and recorded by the operator or they could be unrecorded leaks.
5. Fugitive emissions: Gas leaks, called fugitive emissions, occur readily from many components in CS facilities; such problems will increase as equipment ages. A study of CS stations in Texas is an example.

“In the Fort Worth, TX area, researchers evaluated compressor station emissions from eight sites, focusing in part on fugitive emissions. A total of 2,126 fugitive emission points were identified in the four month field study of 8 compressor stations: 192 of the emission points were valves; 644 were connectors (including flanges, threaded unions, tees, plugs, caps and open-ended lines where the plug or cap was missing); and 1,290 were classified as Other Equipment. The Other category consists of all remaining components such as tank thief hatches, pneumatic valve controllers, instrumentation, regulators, gauges, and vents. 1,330 emission points were detected with an IR camera (i.e. high-level emissions) and 796 emission points were detected by Method 21 screening (i.e. low-level emissions). Pneumatic Valve Controllers were the most frequent emission sources encountered at well pads and compressor stations.”

Eastern Research Group (2011).

Table 1. Examples of air pollutants allowed for release by compressor stations. Air pollutants (pounds/year) are estimates provided by the companies for permits in West Virginia and Pennsylvania in recent years. Total compressor engine horsepower (hp) is noted. Sources: Janus and Tonkin CS Permits at WV DEP website. Shamrock CS permit. Buffalo CS, Washington, Co PA – PENNSYLVANIA BULLETIN, VOL. 45, NO. 16 APRIL 18, 2015.

Pollutant	Term	Janus (WV) 22,000 hp	Tonkin (WV) 4390 hp	Shamrock* (PA) 4140 bhp	Buffalo ** (PA) 20,000 hp + 5,000 bhp
Nitrogen Oxides	NOx	254,400	248,000	170,000	155,800
Volatile Organic Compounds	VOC	191,200	30,000	66,000	77,000
Carbon Monoxide	CO	118,200	80,000	154,000	144,400
Sulfur Dioxide	SO2	1,400	400	10,000	5,400
Hazardous Air Pollutants-Total	HAP	48,200	3,280	19,400	30,000
Formaldehyde			1,080	12,800	12,200
Benzene			540
Ethylbenzene			60
Toluene			140
Xylene			200
Hexane			500
Acetaldehyde			600
Acrolein			160
Total Particulate Matter (PM-2.5, PM-10-separate or combined)	PM	18,200	11,000	32,000	PM-10       32,000 PM-2.5      32,000
TOTAL TOXINS		631,600	372,680	417,400	444,600
Carbon Dioxide Equivalents	CO2-e	29,298,000	27,200,000	367,000,000	214,514,000

 

Health Effects of Compressor Station Emissions

Several toxic chemicals are released by individual CS in amounts that range from a few thousand pounds to a quarter of a million pounds per year (Tables 1 & 2) as described below.

• Nitrous Oxides (NOx) are often the largest total amount of emissions from fossil fuel machinery. In CS, these oxides are formed when a fossil fuel such as methane or diesel is combusted to produce the energy to compress and propel gases. NOx contribute to acid rain. Excess acids in rain lower the pH of waters, in some cases to levels that dissolve toxic metals in drinking water supplies. NOx also trigger the formation of ozone, a substance well known to impair lungs.
• Ozone forms when oxygen reacts with nitrous oxides, carbon monoxide, and a wide range of volatile organic compounds. Ozone exposure can trigger asthma and heart attacks in sensitive individuals, and for healthy people, ozone causes breathing problems in the short term and eventual scarring of lungs and impaired function.
• Volatile Organic Compounds (VOCs) are gaseous compounds containing carbon, such as benzene and formaldehyde. In air pollution regulation, the EPA lists many compounds as VOC, but excludes carbon dioxide, carbon monoxide, methane and butane. Many VOC’s are toxic in themselves (Tables 2, 3 and 4). Also, several VOC’s react to form ozone.  https://www.epa.gov/air-emissions-inventories/what-definition-voc
• Carbon Monoxide (CO) is another product of fossil fuel combustion and another contributor to ozone formation. CO is directly toxic because it prevents oxygen from binding to the blood.
• Sulfur Dioxide (SO₂) adds to lung irritation. It also contributes to acid rain, lowering the pH of water and increasing the ability of toxic metals to dissolve in water supplies.
• Hazardous Air Pollutants (HAP) include highly toxic substances such as formaldehyde and benzene, which are known carcinogens, as well as the other substances known to be emitted from CS (Tables 3 & 4). The EPA lists 187 substances as HAP, which include many VOC’s as well as some non-organic chemicals such as arsenic and radionuclides including Radon. (https://www.epa.gov/haps/initial-list-hazardous-air-pollutants-modifications)
• Particulate Matter (PM) usually refers to particles in small size classes. Most state or federal regulations address measures of particles less than 10 microns (PM-10) and some monitoring systems separate out particles less than 2.5 microns (PM-2.5). Particles in either of those size ranges are not visible, but highly damaging because they travel deep into the lungs where they irritate tissues and impair breathing. Also, these tiny particles carry toxins from air into the blood passing through the lungs. This blood transports substances directly to the brain where toxins can quickly impair the nervous system and subsequently impact other organs. (https://www.epa.gov/pm-pollution/particulate-matter-pm-basics)

Health impacts from many of the substances released by CS are well-known in medical research. For example, many of the VOC and HAP compounds permitted for release by state agencies are known carcinogens (Table 3). Many of these substances also impact the nervous system as shown in the organic compounds measured in CS in PA and listed in Table 4. Also, a study of 18 CS in New York by Russo and Carpenter (2017) found that all 18 CS released substances with known impacts on the nervous system and total annual emissions were over five million pounds, among the highest of all types of emissions (Table 5). Russo and Carpenter also found high annual emissions of over five million pounds for substances known to be associated with each of the following other health problems: digestive problems, circulatory disorders, and congenital malformations.

Congenital defects were significantly more common for mothers living in a 10-mile radius of denser shale gas development in Colorado compared to reference populations (MacKenzie et al. 2014). Currie et al. (2017) examined over a million birth records in Pennsylvania and found statistically significant increased frequencies of low birth weight and negative health scores for infants born to mothers within 3 km of unconventional gas wells compared to matching populations more distant from shale gas developments. Such developments include a wide range of gas infrastructure including CS and also high truck traffic and fracking. One plausible mechanism for harm to developing babies is exposure to VOCs such as benzene, toluene and xylene associated with CS and well operations. These VOC’s are classified by the Agency for Toxic Substances and Disease Registry as known to cross the placental barrier and cause harm to the fetus including birth deformities.

In sum, CS are a significant source of air pollutants with direct and indirect impacts on health. One indirect impact especially important during the COVID-19 pandemic in 2020, is the increased incidence and severity of respiratory viral infections in populations living in areas with poor air quality. Ciencewicki, and Jaspers (2007) write, “a number of studies indicate associations between exposure to air pollutants and increased risk for respiratory virus infections.”

Table. 2. Health effects of air pollutants permitted for release by compressor stations.

Pollutant	Health Effects
Particulate Matter	Impairs lungs and transfers toxins into body when microscopic particles carry chemicals deep into lungs and release into bloodstream.
Nitrogen Oxides	Forms ozone that impairs lung function which can trigger asthma and heart attacks and scars lungs in the long term. Forms acid rain that dissolves toxic metals into water supplies.
Volatile Organic Compounds	Includes a wide variety of gaseous organic compounds, some of which cause cancer. Many VOC react to form ozone that impairs lungs as noted above.
Carbon Monoxide	Blocks ability of blood to carry oxygen. Also forms ozone that impairs lungs as noted above.
Sulfur Dioxide	Irritates lungs, triggering respiratory and heart distress. Forms acid rain that dissolves toxic metals into water supplies.
Hazardous Air Pollutants	Category of various toxic compounds many of which impact the nervous system. Includes formaldehyde, benzene and several other carcinogens.
Total Toxins	Sum of emissions of all toxins. Exposure to multiple toxins exacerbates harm directly through impairment of lungs and circulatory system and indirectly through injury to detoxification mechanisms, such as liver function.
Carbon Dioxide Equivalents	A measure of the combined effects of greenhouse gases such as CO2 and Methane expressed in a standard unit equivalent to the heat trapping effect of CO2. Greenhouse gases trap heat and worsen climate change and related harm to health when increased air temperatures directly cause stress directly and indirectly accelerate ozone formation.

 

Table 3. Gas industry list of carcinogenicity rating for Hazardous Air Pollutants (HAPs) released by compressor stations in a factsheet prepared by EQT for Janus compressor, WV. 2015 Source: DEP.

Substance	Type	Known/Suspected Carcinogen	Classification
Acetaldehyde	VOC	Yes	B2-Probable Human Carcinogen
Acrolein	VOC	No	Inadequate Data
Benzene	VOC	Yes	Category A – Known Human Carcinogen
Ethyl-benzene	VOC	No	Category D Not Classifiable
Biphenyl	VOC	Yes	Suggested Evidence of Carcinogenic Potential
1,3 Butadiene	VOC	Yes	B2-Probable Human Carcinogen
Formaldehyde	VOC	Yes	B1- Probable Human Carcinogen
n-Hexane	VOC	No	Inadequate Data
Naphthalene	VOC	Yes	C- Possible human Carcinogen
Toluene	VOC	No	Inadequate Data
2,3,4-Trimethlypentane	VOC	No	Inadequate Data
Xylenes	VOC	No	Inadequate Data

 

Table 4. Center for Disease Control list of health effects for volatile organic carbons measured by PA DEP near compressor station. Source: CDC.

Substance	Exposure Symptoms	Target Organs
Ethylbenzene	Irritation to eyes and nose; nausea, headache; neuropath; numb extremities, muscle weakness; dermatitis; dizziness	Eyes, skin, respiratory system, central nervous system, peripheral nervous system
n-Butane	Drowsiness	Central nervous system
n-Hexane	Irritation to eyes, skin & respiratory system; headache, dizziness; nausea	Eyes, skin, respiratory system, central nervous system
2-Methyl Butane	n/a	n/a
Iso-butane	Drowsiness, narcosis, asphyxia	Central nervous system

 

Table 5. Amounts of pollutants known to be associated with health impacts in a review of 18 New York compressor stations. Emissions were grouped and tallied based on their impacts on disorders classified by ICD codes as defined by the International Statistical Classification of Diseases and Related Health Problems (ICD), a medical classification list by the World Health Organization. Source: Copy of Table 3.17b, Russo and Carpenter 2017.

ICD-10			Facilities				Chemicals				Pounds
#	Description		‘08	‘11	‘14	Tot	‘08	‘11	‘14	Tot	2008	2011	2014	Total
1	Q00-Q89	Congenital malformations and deformations	18	18	17	18	57	54	54	57	4,393,806	6,607,676	5,900,691	16,902,175
1.1	Q00-Q07	Nervous system	18	18	17	18	16	16	16	16	4,068,877	5,882,704	5,258,344	15,209,926
1.2	Q10-Q18	Eye, ear, face and neck	15	15	12	15	4	4	4	4	5,825	19,569	11,475	36,869
1.3	Q20-Q28	Circulatory system	18	18	17	18	10	10	10	10	4,269,779	6,336,905	5,651,896	16,258,581
1.4	Q30-Q34	Respiratory system	14	8	7	14	4	4	4	4	150	107	113	372
1.5	Q35-Q45	Digestive system	18	18	17	18	17	17	17	17	4,386,043	6,586,345	5,884,324	16,856,713
1.6	Q50-Q56	Genital organs	6	7	8	8	2	2	2	2	1,399	4,373	2,612	8,385
1.7	Q60-Q64	Urinary system	18	17	16	18	9	9	9	9	119,382	254,922	237,359	611,663
1.8	Q65-Q79	Musculoskeletal system	18	18	16	18	19	19	19	19	122,314	262,300	243,932	628,547
1.9	Q80-Q89	Other	18	18	17	18	55	52	52	55	2,124,445	3,614,575	3,413,375	9,152,395
2	Q90-Q99	Chromosomal abnormalities, nec	18	18	16	18	30	31	31	32	120,669	256,739	239,709	617,118
	Q00-Q99	Total	18	18	17	18	57	56	56	59	4,393,806	6,607,676	5,900,691	16,902,175

Regional Air Toxins and Cancer Risk in Southwestern Pennsylvania

Cancer risks from HAPs have been elevated for many years in several areas of Southwestern PA, as noted in a map from 2005 (Figure 2), when most air pollution was from urban traffic and single sources such as coke works and unconventional gas development (UCGD) had just begun in the region. The cancer risk pattern changed by 2014 (Figure 3). The specific numbers of excess cancer risk predicted for each location cannot be compared between the two maps because each map was produced using different sources of information and models. The pattern, however, can be compared and shows that elevated cancer risk is now more widespread across Southwestern PA and no longer primarily in Allegheny County.

Cancer risk maps are constructed by the EPA office of National Air Toxics Assessment (NATA) using models of reported air toxics and their relationship to cancer as a risk factor, as defined by NATA: “A risk level of “N”-in-1 million implies that up to “N” people out of one million equally exposed people would contract cancer if exposed continuously (24 hours per day) to the specific concentration over 70 years (an assumed lifetime). This would be in addition to cancer cases that would normally occur in one million unexposed people.” (https://www.epa.gov/national-air-toxics-assessment/nata-glossary-terms) In the current context, the NATA models are useful to compare the relative differences in air quality from a public health perspective, assuming the data on air pollutants is complete.

Another, very different statistic regarding cancer is the rate of cancer, also called the incidence. This number is based on actual reported cases and applies to cancers that occur due to all causes. The cancer rate, therefore, is a much higher number than a risk factor. For example, according to the US Center for Disease Control, the annual rate of new cases of cancer in PA in 2016, the most recent year reported, was 482.5 per 100,000 people. Compared to other states, PA is among the ten states with the highest cancer incidence. In the US, one in four people die from cancer, placing it second to heart disease as a leading cause of death. (https://gis.cdc.gov/Cancer/USCS/DataViz.html). Compared to other nations, the US has the fifth highest cancer rate, with 352 new cases each year per 100,000 people. (https://www.wcrf.org/dietandcancer/cancer-trends/data-cancer-frequency-country)

Compressor station emissions contribute to air pollutants known to be associated with cancer. For example, in a review of emissions for 18 CS in New York, Russo and Carpenter (2017) found that most or all CS released substances associated with a wide range of cancers (Table 6). Up to 56 such chemicals were emitted in amounts that totaled over 1 million pounds each year.

Maps of cancer risk are likely to be under-reporting risk levels in both the amount rates of risk and also the locations. Cancer risks from serious air pollutants cannot be properly mapped for several reasons. First, reports on concentrations of HAP in emissions are limited. HAP emissions are in accounts required only from large facilities, and thus, smaller operations, such as many CS, are likely be ignored. Second, general air quality monitoring stations are limited in location and do not measure HAP. For example, the PA DEP maintains 47 air quality stations dispersed among over 60 counties (http://www.dep.state.pa.us/dep/deputate/airwaste/aq/aqm/pollt.html). Most stations report hourly measures of Ozone and PM-2.5, and only a handful also monitor one or more other substances such as CO, NOx, SO ₂ or H₂S. One county in Southwestern PA has additional air quality stations. Allegheny has a county health department that maintains 17 stations to report real-time air quality based on Ozone, SO₂ or PM-2.5 (https://alleghenycounty.us/Health-Department/Programs/Air-Quality/Air-Quality.aspx).

In sum, cancer risk estimates from air pollution fall short in the following ways:

• Estimates of air quality do not reflect the reality of air pollution from CS as well as many other new sources such as increased truck traffic associated with shale gas development.
• Tallies of annual emissions do not represent the actual exposures of individuals to pulses of toxins.
• Models of air pollution and cancer are not sufficiently based on real world studies of impacts from multiple toxins in short and long-term exposures.

Figure 2. Cancer risk map in Southwestern Pennsylvania in 2005 from the National Air Toxics Assessment program in the EPA. Total Lifetime Cancer Risk from Hazardous Air Pollutants (HAP) per million. Colors indicate yellow for 28-78, gold for 79-95, light orange for 99-148, orange for 149-271, bright orange for 272-517, and red for 518-744 excess cancer risk per million. (https://www.epa.gov/national-air-toxics-assessment)

Figure 3. Cancer risk map in Southwestern Pennsylvania in 2014 from the National Air Toxics Assessment in the EPA. Facilities are locations where air quality information was available for modeling. Total Risk of cancer as a baseline was assumed to be 1 per 1,000,000.  Estimates of risk predict known air pollution sources alone will cause 1-24 excess cancers per million in Light Pink areas, 25-49 excess cancers per million in Gray areas, and 50-74 excess cancers per million in Blue areas. Source: EPA.

Table 6. Amounts of pollutants known to be associated with cancer in a review of 18 New York compressor stations. Emissions were grouped and tallied based on their impacts on disorders classified by ICD codes as defined by the International Statistical Classification of Diseases and Related Health Problems (ICD), a medical classification list by the World Health Organization. Source: Copy of Table 3b, Russo and Carpenter 2017.

 

ICD-10			Facilities				Chemicals				Pounds
#	Code	Description	‘08	‘11	‘14	Tot	‘08	‘11	‘14	Tot	2008	2011	2014	Total
1	C00-C97	Malignant neoplasms	18	18	17	18	53	54	54	56	744,394	1,679,621	1,583,745	4,007,761
2	C00-C14	Lip, oral cavity and pharynx	18	18	16	18	12	14	14	14	118,992	254,897	238,943	612,833
3	C15-C26	Digestive organs	18	18	16	18	37	38	38	38	121,690	258,670	241,866	622,227
4	C30-C39	Respiratory system and intrathoracic organs	18	18	17	18	36	37	37	38	740,798	1,673,574	1,579,882	3,994,254
5	C40-C41	Bone and articular cartilage	18	18	17	18	33	34	34	35	694,106	1,551,399	1,492,704	3,738,210
6	C43-C44	Skin	16	15	13	16	12	12	12	14	2,362	5,008	4,029	11,400
7	C45-C49	Connective and soft tissue	17	17	15	17	17	17	17	17	1,929	5,074	4,639	11,643
8	C50-C58	Breast and female genital organs	18	18	16	18	23	25	25	25	361,015	823,303	663,237	1,847,556
9	C60-C63	Male genital organs	18	17	16	18	12	13	13	13	111,217	233,176	224,147	568,541
10	C64-C68	Urinary organs	18	18	16	18	24	24	24	25	119,062	255,474	238,596	613,133
11	C69-C72	Eye, brain and central nervous system	18	18	16	18	20	20	20	20	121,282	258,655	241,954	621,892
12	C73-C75	Endocrine glands and related structures	18	17	16	18	10	10	10	10	112,911	235,120	225,269	573,300
13	C76-C80	Secondary and ill-defined	17	16	14	17	6	6	6	6	2,054	5,690	5,771	13,516
14	C81-C96	Malignant neoplasms, stated or presumed to be primary, of lymphoid, haematopoietic and related tissue	18	18	16	18	31	31	31	31	364,338	833,140	671,245	1,868,724
15	C97	Malignant neoplasms of independent (primary) multiple sites	0	0	0	0	0	0	0	0	0	0	0	0
16	D00-D09	In situ neoplasms	16	15	13	16	3	3	3	3	3,313	7,557	6,606	17,477
17	D10-D36	Benign neoplasms	17	17	14	17	27	27	27	27	12,499	35,013	23,068	70,580
18	D37-D48	Neoplasms of uncertain or unknown behavior	18	18	16	18	39	40	40	41	121,277	257,142	240,115	618,535

Measurements of Compressor Station Emissions

Studies of real-world concentrations of air pollutants from CS emissions are lacking, but some reports exist. Of these, a few records are in peer-reviewed studies, and cited in reviews such as Saunders et al. 2018.  A few published reports are described below. They all show the high variation over time for CS emissions and the occurrence of peak concentrations.

Macey et al. (2014) observed ambient air near CS contained toxins at concentrations that impair health. They collected grab samples of air from industrial sites including CS in Arkansas and Pennsylvania and analyzed them for toxins using EPA approved methods. Most of the CS studied in Arkansas (Table 6) and Pennsylvania (Table 7) released formaldehyde at amounts associated with a cancer risk from exposure to this substance of 1/10,000 which is equivalent to 100 times higher risk than the widely accepted baseline risk of 1 per million. This means the amounts of formaldehyde found near CS substantially increased the risk of cancer using well-established federal analyses (https://www.atsdr.cdc.gov/hac/phamanual/appf.html).  Some toxins Macey et al. recorded are less well studied than formaldehyde and benzene. For example, 1,3-butadiene is classified by the EPA as a known human carcinogen, but a calculation of cancer risk for this substance is lacking. Air samples in the Macey study were collected close to the CS (e.g., 30-42m) and at greater distances (e.g., 254-460m). Those distant samples were well beyond the 750-foot set-back rule for Pennsylvania. At all these distances, air movement modeling predicts that toxins released from a source such as a CS are likely to travel downwind within the air mass under most weather conditions, thus exposing residents near and further from CS. Many people, therefore, in homes, schools and businesses that are downwind of CS are likely to experience serious air toxins at concentrations that harm their health.

Air toxins were also measured by the Pennsylvania Department of Environmental Protection in 2010 in a variety of unconventional gas extraction facilities including one CS in Washington County, PA. Brown et al. (2015) reported these data, showing the concentrations that citizens could experience near a compressor station varied greater than tenfold within a day and among consecutive days (Table 8). The length of time for peak concentrations was unknown, but Brown et al. used a model of weather including wind patterns to estimate citizens are likely to experience 118 peak concentrations per year.

Goetz et al. (2015) sampled air in Marcellus shale regions of Pennsylvania for short periods (1-2.5 hrs.) at distances 480-1100 meters from eight CS, four with relatively small capacity (5,000-9,000 hp) and four with moderate capacity (14,000-17,000 hp). They found that each CS had a different pattern of relatively higher concentrations of some pollutants, such as NOX versus other pollutants, e.g., CO. Also, totals of all pollutants did not correlate with compressor engine capacity, probably because the CS they sampled include a mix of engines using fossil fuels and electric power. Goetz et al. concluded with recommendations for more comprehensive and longer-term monitoring to better understand air pollution from CS and all components in shale gas development.

Radionuclides in CS emissions are almost never measured, even though Marcellus shales are well known for containing elevated amounts of radiologic substances such as uranium, radium and radon. The only published report of testing for radionucleotides in CS emissions in PA was a test of a single CS emission for one period of time. In a review of radiation in shale gas industry components, the Pennsylvania Department of Environmental Protection (PA DEP) measured radon (Rn) in ambient air at one CS by deploying sample bags in four cardinal directions at the fence line at a height of 5 feet for 62 days. They reported Rn concentrations of 0.1-0.8 pCi/L, values they stated were within the range of outdoor air in the US.  (https://www.dep.pa.gov/Business/Energy/OilandGasPrograms/OilandGasMgmt/Oil-and-Gas-Related-Topics/Pages/Radiation-Protection.aspx)  Given the high variation of amounts of emissions from CS and variable chemistry in sources of gases released from combustion, blowdowns and leaks, frequent testing for radionucleotides should be standard in monitoring CS emissions.

Methane is the substance tracked most often in emissions from CS and other gas industry facilities because of its central role in operations, requirements to avoid explosive concentrations, and readily available measurement technology, in comparison to other substances emitted from CS. Although methane emissions from CS are not always correlated with amounts of other, more toxic emissions, patterns observed in plumes of methane from CS are likely to reflect elevated concentrations of other harmful substances from CS.

Nathan et al (2015) sampled methane emissions from one CS in the Barnett shale region using a sensor carried on a model aircraft. The open-path, laser sensor produced measures with a precision of 0.1 ppmv over short intervals, allowing researchers to see emission variation in time and space as the aircraft changed position. Based on 22 flights within a week period, they observed a substantial range in methane released from 0.3 – 73 g CH4 per second. These values calculate to 0.02 – 6.3 metric tons of methane per day, a range that matches that estimated by Goetz of 0.5 – 9 metric tons per day. In addition, Nathan et al. found high variability in concentrations at different heights, as the emission plumes shifted in response to wind velocity, direction and topography. They recommend caution in interpretations of ground-based emission monitors and called for more monitoring of air movements and emissions at different elevations.

Payne et al. 2017 confirmed these ideas when they mapped plumes of methane in CS in New York and Pennsylvania using a sensor capable of recording methane in parts per million (ppm) every 0.25 – 5 seconds. The sensor was located on a mobile unit that marked GPS location. They found high variability in the shape and extent of plumes. For example, one of most extensive plumes was recorded near Dimock, Pennsylvania in a locale with CS as the only major source of methane. Researchers recorded the highest concentrations of methane in the study, 22 ppm, at 500 m from the CS, with a second peak of 0.6 ppm noted over 1 km from the CS and elevated methane as far as 3 km from the site (Figure 4). Wind direction did not always predict the shape of the plume, but data collection was restricted by the path of the sensor and the transport vehicle (Figure 8). Most importantly, they found that …“during atmospheric temperature inversions, when near-ground mixing of the atmosphere is limited or does not occur, residents and properties located within 1 mile of a compressor station can be exposed to rogue methane from these point sources.” These residents are likely to also experience excess toxins from CS as well, especially under such weather conditions.

Exposure to peak concentrations of air pollutants have dramatic effects on health for several reasons. First, lungs carry toxins into the blood within seconds, and the blood quickly transfers compounds to the brain and other vital organs. Many of the substances released by compressor stations impact the central nervous system as seen in Table 3, and these toxins are released simultaneously. Citizens, therefore inhaling a plume of emissions will have impacts from the total of these compounds. The health impacts for these combined toxins are unknown, and especially of concern during pregnancy and child development. Exposure studies in animals and humans test individual substances and the Center for Disease Control and NIOSH use these to develop exposure guidelines for a healthy adult in a work-place. In contrast, residents near compressor stations will include citizens of all ages with various health conditions. For example, the American Lung Association determined that over 50% of the 360,000 residents of Westmoreland County are at greater risk for health impairment due to air pollution because they have one or more of these conditions: asthma, diabetes, heart disease, respiratory illness, advanced age (https://www.lung.org/our-initiatives/healthy-air/sota/key-findings/people-at-risk.html).

In sum, the research on CS emissions of methane, air pollutants such as NOx, and hazardous air pollutants such as formaldehyde and benzene, all indicate exposures to CS emissions pose a threat to public health, but the emissions have not yet been fully quantified and modeled. Documenting CS contributions to harmful ambient air quality is feasible, however. The published studies from as far back as 2011 indicate that instrumentation to record substances and weather are readily available. Activities within a station such as compressor function, blowdowns, venting and flaring are all recorded by operators, but such reports are not released to researchers or the public. The science of models that predict public health risks in response to air pollution exposure are highly developed. In sum, operators of CS have the technology to measure emissions and ambient air quality and scientists have the models, but lack of industry data prevents the public from knowing impacts from CS.

 

Table 6. Air toxins found in grab samples near Arkansas compressor stations including concentrations, the Agency for Toxic Substances and Disease Registry (ASTDR), Minimum Risk Level (MRL) exceedance, and the Environmental Protection Agency (EPA) Integrated Risk Information System (IRIS) cancer risk. Source: Copy of Table 4 from Macey et al. 2014.

State/ID	County	Nearest infrastructure	Chemical	Concentration (μg/m3)	ATSDR MRLs exceeded	EPA IRIS cancer risk exceeded
AR-3136-003	Faulkner	355 m from compressor	Formaldehyde	36	C	1/10,000
AR-3136-001	Cleburne	42 m from compressor	Formaldehyde	34	C	1/10,000
AR-3561	Cleburne	30 m from compressor	Formaldehyde	27	C	1/10,000
AR-3562	Faulkner	355 m from compressor	Formaldehyde	28	C	1/10,000
AR-4331	Faulkner	42 m from compressor	Formaldehyde	23	C	1/10,000
AR-4333	Faulkner	237 m from compressor	Formaldehyde	44	C, I	1/10,000
AR-4724	Van Buren	42 m from compressor	1,3-butadiene	8.5	n/a	1/10,000
AR-4924	Faulkner	254 m from compressor	Formaldehyde	48	C, I	1/10,000

C = chronic; I = intermediate.

 

Table 7. Air toxins found in grab samples near Pennsylvania compressor stations including concentrations, the Agency for Toxic Substances and Disease Registry (ASTDR), Minimum Risk Level (MRL) exceedance, and the Environmental Protection Agency (EPA) Integrated Risk Information System (IRIS) cancer risk. Source: Copy of Table 5 from Macey et al. 2014

State ID	County	Nearest infrastructure	Chemical	Concentration (μg/m3)	ATSDR MRLs exceeded	EPA IRIS cancer risk exceeded
PA-4083-003	Susquehanna	420 m from compressor	Formaldehyde	8.3		1/10,000
PA-4083-004	Susquehanna	370 m from compressor	Formaldehyde	7.6		1/100,000
PA-4136	Washington	270 m from PIG launcha	Benzene	5.7		1/100,000
PA-4259-002	Susquehanna	790 m from compressor	Formaldehyde	61	C, I, A	1/10,000
PA-4259-003	Susquehanna	420 m from compressor	Formaldehyde	59	C, I, A	1/10,000
PA-4259-004	Susquehanna	230 m from compressor	Formaldehyde	32	C	1/10,000
PA-4259-005	Susquehanna	460 m from compressor	Formaldehyde	34	C	1/10,000

C = chronic; A = acute; I = intermediate.

aLaunching station for pipeline cleaning or inspection tool.

 

Table 8. Variation in air pollutants measured in ug/cubic meter by PA DEP during two sampling times per day for three consecutive days near a compressor station in Southwest PA. Source: Copied from Table 1. Brown et al. 2015 based on data from Southwestern Pennsylvania Short Term Marcellus Ambient Air Sampling Report, Pennsylvania Department of Environmental Protection, Nov. 2010.

May 18		May 19			May 20
Chemical	Morning	Evening		Morning	Evening		Morning	Evening	3-day Average
Ethylbenzene	No detect	No detect		964	2015		10,553	27,088	13,540
n-Butane	385	490		326	696		12,925	915	5,246
n-Hexane	No detect	536		832	11,502		33,607	No detect	15,492
2-Methyl Butane	No detect	230		251	5137		14,271	No detect	6,630
Iso-butane	397	90		No detect	1481		3,817	425	2070

 

 

 

Figure 4. Methane emission plumes from compressor stations near Dimock, Pennsylvania (left) and Springvale, Pennsylvania (right). Source: Copied from Payne et al. 2017.

 

Compressor Station Locations

Prior to 2008, compressor stations were infrequent with one or a few per county broadly distributed across PA as part of gas transport from locations outside of PA (Figure 5). These pipelines were mainly an issue for public health in the case of explosions. Major transmission pipelines use pressures up to 1500 psi. Leaks, therefore, release large amounts of gas much of which is not noticed because it lacks the mercaptan odorant added to household methane. For example, the 30-inch Spectra gas pipeline that exploded in 2016 in Westmoreland County caused a hole 12 feet deep and1500 square feet in area and burned 40 acres. The PA DEP claimed to have measured air quality, but they did not arrive until long after the plume from the fire traveled downwind. This pipeline was transporting gas from one of the largest gas storage facilities in the country, the Sunoco Gas Depot in Delmont, Pennsylvania to New Jersey as part of over 9,000 miles of pipelines in the Texas Eastern system from the Gulf Coast to the Northeast. That section of pipeline was built in 1981 and had recently been increased in pressure, probably using older or newer compressors in nearby locations. Faulty joints between pipeline sections were blamed for the catastrophic release of gas. (Phillips, S. 2016. State Impact, NPR). Immediately after the explosion, while gas continued to pour out of the pipeline, emergency workers needed at least one hour to locate shut-off locations. In general, pipeline shut-offs are sited at compressors stations or at intervals along a pipeline.

CS abundance in counties with shale gas extraction increased over tenfold in the decade after 2005 when the gas industry obtained exemptions to the Clean Water Act and began unconventional gas extraction in Pennsylvania (Figure 6). Permit applications for new wells, pipelines and CS continue throughout southwest Pennsylvania. In PA, the Oil and Gas law states the following: “ In order to allow  for the reasonable development of oil and gas resources, a local ordinance … Shall authorize natural gas compressor stations as a permitted use in agricultural and industrial zoning districts and as a conditional use in all other zoning districts, if the natural gas compressor building meets the following standards:….(i) is located 750 feet or more from the nearest existing building or 200 feet from the nearest lot line, whichever is greater, unless waived by the owner of the building or adjoining lot;”  (Pennsylvania Statutes Title 58 Pa.C.S.A. Oil and Gas §3304). CS and many aspects of the shale gas industry are controlled by this state law.

Each stage of gas extraction involves emissions that can be close or far from the well pad. Most emissions involve diesel engines. Diesel engines are well-known to produce substantial amounts of VOC’s, NOx and particulate pollution (PM-2.5, PM-10). Well pad construction requires intense activity by diesel trucks and earth moving equipment. Well drilling uses diesel engines. From 3 – 5 million gallons of water are used for each fracking event and up to 300 truck visits are needed to transport water for the many wells that are not close to water supplies from piped sources. Trucks are used to transport the 1 – 2 million gallons of produced water that emerges from the well for disposal in injection wells likely to be distant from most wells. Additional waste is carried long distances as well, including drill cuttings and sludge. For example, shale gas industry waste was handled for years in Max Environmental, one of the largest industrial waste sites in the eastern US located in Yukon, Westmoreland County since the 1960’s. Within one mile of Yukon is Reserved Environmental, a waste facility with operations focused since 2008 on processing sludge from fracking into solid cakes to be trucked to other landfills. In sum, all stages of shale gas industry contribute to many poorly documented sources of air pollution likely to be near CS.

The density of CS in some areas such as southwest Pennsylvania impacts the local and regional air quality. For example, Westmoreland County has 50 CS and 341 shale gas wells (https://www.fractracker.org) and some neighboring counties have even more shale gas emission sources. People in Westmoreland County receive pollutants from shale gas activities in their immediate vicinity and additional air pollutants from CS and other industries in neighboring counties. Wind patterns shown in Figure 7 indicate Westmoreland County is frequently downwind from Washington County, a county with a very high density of shale gas operations, and Eastern Allegheny County where large industries such as coke works release substantial amounts of air pollutants.

Figure 5. Compressor Stations prior to 2008 and in around 2013. Source: Copied from article by James Hilton in Pittsburgh Post-Gazette.

 

Figure 6. Compressor Stations in Pennsylvania mapped in 2019. Source: FracTracker Alliance. 2000.

Figure 7. Wind patterns at small airports around Pennsylvania 1991-2005 showing predominant direction of wind and velocity in knots (Orange 0 – 4, Yellow 4 – 7, Turquoise 7 – 11, Medium Blue 11 – 17, Dark Blue 17 – 21). Source: The Pennsylvania State Climatologist.

Costs of Compressor Stations and Air Pollution

As permanent, constant sources of air and noise pollution and safety risks, CS add significant costs to communities. Poor air quality alone is well-established as an economic drain for a region due to many factors including increased health care, lower property values, a declining tax base, and difficulty in attracting new businesses or housing development. Litovitz et al. (2013) estimated that, compared to other activities of shale gas extraction, CS made up the majority of the annual emissions of important air toxins in 2011, and therefore a majority of the damages from air pollution, totaling 4 – 24 million dollars of the 7 – 32 million dollars of the aggregate air pollution damages from gas operations (Table 9).

Litovitz and others recognize that the costs of damages from the gas industry air pollution in 2011 may appear smaller than the state-wide impacts from other industries, such as coal burning power plants and coke production, but that appearance deserves a second look. First, shale gas extraction activities are concentrated in a few regions of Pennsylvania, and local air quality is most relevant to public health and local economics such as property values. Second, emissions from gas extraction in 2011 was only in its early stages in Pennsylvania and shale gas operations will expand greatly unless regulations change, while coal-fired power plants are declining due to the advanced age of most facilities. For example, in Westmoreland County, PA alone there are over 50 CS in 2020, the number currently in the entire state of New York, where unconventional gas development was suspended due, in large part, to concerns for public health. Costs from one aspect of an energy sector can be viewed in the context of economic and other benefits of alternative energy efforts. For example, Jacobson et al. (2013) estimated that shifting to clean, renewable energy in NY state would prevent 4000 premature deaths each year and save $33 billion/year through air pollution reductions that impact health care, crop production and other costs. Jacobson et al. used government data in their models regarding health benefits and also identified substantial job growth during and after the transition away from fossil fuels toward renewable energy. Pennsylvania has the potential to attain similar benefits in air quality, public health, savings and job growth gained from a shift to clean, renewable energy in place of fossil fuels.

Table 9.  a) Emissions from shale gas industry in 2011 throughout Pennsylvania in metric tons per year. b) Costs of damages due to air pollution from shale gas extraction in 2011 throughout Pennsylvania. Copied from Tables 5 and 6 in Litovitz et al. 2013.

a)

Activities	VOC	NOx	PM2.5	PM10	SOx
(1) Transport	31–54	550–1000	16–30	17–30	0.82–1.4
(2) Well drilling and hydraulic fracturing	260–290	6600–8100	150–220	150–220	6.6–190
(3) Production	71–1800	810–1000	15–78	15–78	4.8–6.2
(4) Compressor stations	2200–8900	9300–18 000	280–1100	280–1100	0–340
Totalᵃ	2500–11 000	17 000–28 000	460–1400	460–1400	12–540

ᵃ These totals are reported to two significant figures, as are all intermediate emissions values in this document. The activity emissions may not exactly sum to the totals.

b)

Activities	Timeframe	Total regional damage for 2011 ($2011)	Average per well or per MMCF damage ($2011)
(1) Transport	Development	$320 000–$810 000	$180–$460 per well
(2) Well drilling, fracturing	Development	$2 200 000–$4 700 0	$1 200-$2 700 per well
(3) Production	Ongoing	$290 000–$2 700 0	$0.27-$2.60 per MMCF
(4) Compressor stations	Ongoing	$4 400 000–$24 000 000	$4.20-$23.00 per MMCF
(1)-(4) Aggregated	Both	$7 200 000–$32 000 000	NA

Major Studies Cited in Text:

Brown, David, Celia Lewis, Beth I. Weinberger and Heather Bonaparte. 2014. Understanding air exposure from natural gas drilling put air standards to the test. Reviews in Environmental Health. https://doi.org/10.1515/reveh-2014-0002

Brown, David, Celia Lewis and Beth I. Weinberger. 2015. Human exposure to unconventional natural gas development; a public health demonstration of high exposure to chemical mixtures in ambient air. Journal of Environmental Science and Health (Part A) 50: 460-472.

Ciencewicki, J. and I. Jaspers 2007. Air Pollution and Respiratory Viral Infection. Inhalation Toxicology 19:1135–1146, DOI: https://doi.org/10.1080/08958370701665434

Currie, J, M Greenstone and K Meckel. 2017. Hydraulic fracturing and infant health: New evidence from Pennsylvania.   Science Advances 2017;3:e1603021

Eastern Research Group, Inc. and Sage Environmental Consulting, LP. City of Fort Worth natural gas air quality study: final report. July 13, 2011. http://fortworthtexas.gov/gaswells/air-quality-study/final/

Goetz, J.D. E. Floerchinger, E., C. Fortner, J. Wormhoudt, P. Massoli, W. Berk Knighton, S.C. Herndon, C.E. Kolb, E. Knipping, S. L. Shaw, and P. F. DeCarlo. 2015. Atmospheric Emission Characterization of Marcellus Shale Natural Gas Development Sites. Environ. Sci. Technol. 49, 7012−7020. DOI: https://doi.org/10.1021/acs.est.5b00452

Jacobson, MZ, RW Howarth, MA Delucchi, ST Scobie, JH Barth, M Dvorak, M Klevze, H. Hatkhuda, B. Mirand, NA Chowdhury, R Jones, L Plano, AR Ingraffea. 2013. Examining the feasibility of converting New York State’s all-purpose energy infrastructure to one using wind, water, and sunlight. Energy Policy 57: 585-601.

Litovitz, A., A. Curtright, S. Abramzon, N. Burger and C. Samaras. 2013. Estimation of regional air-quality damages from Marcellus Shale natural gas extraction in Pennsylvania. Environ. Res. Lett. 8; 014017 (8pp) doi:10.1088/1748-9326/8/1/014017. https://iopscience.iop.org/article/10.1088/1748-9326/8/1/014017/meta

Macey, G.P., Breech, R., Chernaik, M. (2014) Air concentrations of volatile compounds near oil and gas production: a community-based exploratory study. Environ Health 13, 82 (2014). https://doi.org/10.1186/1476-069X-13-82

McKenzie, LM, G Ruisin, RZ Witter, DA Savitz, LS Newman, JL Adgate. 2014. Birth Outcomes and Maternal Residential Proximity to Natural Gas Development in Rural Colorado.  Environmental Health Perspectives Vol 22.  http://dx.doi.org/10.1289/ehp.1306722.

Nathan BJ, LM Golston, AS O’Brien , K Ross, WA Harrison, L Tao, DJ Larry, DR Johnson, AN Covington, NN Clark, MA Zondlo. 2015. Environ Sci Technol. 2015   Near-Field Characterization of Methane Emission Variability from a Compressor Station Using a Model Aircraft. Environ Sci Technol. 2015 Jul 7;49(13):7896-903 doi: 10.1021/acs.est.5b00705.

Payne, RA, P Wicker, ZL Hildenbrand, DD Carlton, and KA Schug. 2017. Characterization of methane plumes downwind of natural gas compressor stations in Pennsylvania and New York. Science of The Total Environment  580:1214-1221

Russo, PN and DO Carpenter 2017. Health Effects Associated with Stack Chemical Emissions from NYS Natural Gas Compressor Stations: 2008-2014 Institute for Health and the Environment, A Pan American Health Organization / World Health Organization Collaborating Centre in Environmental Health, University at Albany, 5 University Place, Rensselaer New York. Https://www.albany.edu/about/assets/Complete_report.pdf

Saunders, P.J., D. McCoy. R. Goldstein. A. T. Saunders and A. Munroe. 2018.   A review of the public health impacts of unconventional natural gas development Environ Geochem Health 40:1–57. https://doi.org/10.1007/s10653-016-9898-x

 

Appendix

Compressor Stations in Westmoreland Co. PA in Dec 2019, based on information from FracTracker Alliance, Pennsylvania Department of Environmental Protection Air Quality Report, and the Department of Homeland Security.

ID #	Facility #	Name/Operator	Municipality	Latitude	Longitude	Status
627743	645570	CNX GAS CO/HICKMAN COMP STA	Bell Twp	40.5174	-79.5498	Active
693305	696606	PEOPLES TWP/RUBRIGHT COMP STA	Bell Twp	40.5278	-79.5561	Active
626482	644726	CNX GAS CO/BELL POINT COMP STA	Bell Twp	40.5413	-79.5338	Active
na	na	NORTH OAKFORD	Delmont	40.4018	-79.5597	Active
714057	713241	RW GATHERING LLC/ECKER BERGMAN RD COMP STA	Derry Twp	40.3533	-79.3028	Active
760724	752063	RE GAS DEV/ORGOVAN COMP STA	Derry Twp	40.3857	-79.4019	Active
736807	732436	RW GATHERING LLC/SALEM COMP STA	Derry Twp	40.3908	-79.3361	Active
714057	713241	RW GATHERING LLC/ECKER BERGMAN RD COMP STA	Derry Twp	40.3533	-79.3028	Active
774714	766854	EQT GATHERING LLC/DERRY COMP STA	Derry Twp	40.4511	-79.3161	Active
na	na	Layman Compressor, Range Resources Appalachia, LLC	East Huntingdon	40.1113	-79.6345	Unknown
na	na	Key Rock Energy/LLC	East Huntingdon	40.1228	-79.6489	Unknown
662759	673466	Kriebel Minerals Inc./Sony Compressor Station (Inactive)	East Huntingdon	40.181	-79.5882	Unknown
662781	673477	Lynn Compressor, Kriebel Minerals Inc.	East Huntingdon	40.1798	-79.5557	Unknown
636316	660570	Range Resources Appalachia/ Layman Compressor Station	East Huntingdon	40.1086	-79.6359	Unknown
na	na	Keyrock Energy LLC/ Hribal Compresor Station, East Huntingdon, Pa. (active)	East Huntingdon	40.1353	-7905653	Unknown
761545	752755	KeyRock Energy LLC/ Hribal Compressor Station (Active)	East Huntingdon	40.1333	-79.55	Unknown
649767	663499	Range Resources Appalachia/Schwartz Comp. Station	East Huntingdon	40.0879	-79.601	Unknown
652968	665874	TEXAS KEYSTONE/FAIRFIELD TWP COMP STA	Fairfield Twp	40.3363	-79.1786	Active
557780	572987	EQUITRANS LP/W FAIRFIELD COMP STA	Fairfield Twp	40.3333	-79.1167	Active
675937	683303	DIVERSIFIED OIL & GAS LLC/MURPHY COMP SITE	Fairfield Twp	40.3362	-79.1122	Active
812881	806928	TEXAS KEYSTONE INC/ MURPHY COMP STA	Fairfield Twp	40.3543	-79.1123	Active
na	na	SOUTH OAKFORD/Dominion	Greensburg	40.365	-79.5585	Unknown
na	na	OAKFORD	Greensburg	40.3848	-79.5489	Active
na	na	DELMONT	Geensburg	40.382	-79.5554	Active
496667	626720	Silvis Compressor Station, Exco Resources Pa. Inc	Hempfield	40.2022	-79.5526	Unknown
na	na	Dominion Trans Inc., Lincoln Heights	Hempfield Township	40.3004	-79.6193	Active
812660	806731	CNX Gas Co. LLC	Hempfield Township	40.2957	-79.6277	Active
812661	806732	CNX Gas Co. LLC/ Jackson Compressor Station, Status: Active	Hempfield Township	40.2931	-79.6119	Unknown
601521	626775	PEOPLES NATURAL GAS CO/ARNOLD COMP STA	Lower Burrell City	40.3623	-79.4316	Active
812883	806930	TEXAS KEYSTONE INC/LOYALHANNA	Loyalhanna Twp	40.4514	-79.4727	Inactive
na	na	J.B. TONKIN	Murrysville Boro	40.4629	-79.6402	Active
815083	809310	HUNTLEY & HUNTLEY INC/BOARST COMP STA	Murrysville Boro	40.4686	-79.6417	Inactive
735725	731655	MTN GATHERING LLC/10078 MAINLINE COMP STA	Murrysville Boro	40.4708	-79.65	Active
241708	276314	Dominion Trans Inc/Jeannette	Penn Township	40.3317	-79.5935	inactive
na	701239	DOMINION ENERGY TRANS INC/ROCK SPRINGS COMP STA	Salem Twp	40.4052	-79.5546	Unknown
na	na	OAKFORD	Salem Twp	40.4052	-79.5546	Unknown
465965	495182	EQT GATHERING/SLEEPY HOLLOW COMP STA	Salem Twp	40.3634	-79.5426	Inactive
465965	495182	EQT GATHERING/SLEEPY HOLLOW COMP STA	Salem Twp	40.3634	-79.5426	Inactive
483173	512126	COLUMBIA GAS TRANS CORP/DELMONT COMP STA	Salem Twp	40.3871	-79.5638	Active
707759	708010	LAUREL MTN MIDSTREAM OPR LLC/SALEM COMP STA	Salem Twp	40.3782	-79.4929	Active
459024	488214	CNX Gas Co./ Jacobs Creek Compressor Station,	South Huntingdon Twp	40.1172	-79.6681	Unknown
634559	650802	Rex Energy I LLC/Launtz	Unity Twp	40.3325	-79.4295	Unknown
na	668776	Keyrock Energy LLC/ Unity Compressor Station	Unity Twp	40.2251	-79.5109	Unknown
na	na	Nelson/RE Gas Dev LLC	UnityTwp	40.3378	-79.4348	Unknown
657366	66932	People’s Natural Gas/ Latrobe Compressor Station	Unity Twp	40.3075	-79.4369	Inactive
812662	806733	CNX Gas Co. LLC, Troy Compressor Station	Unity Twp	na	na	Unknown
657366	564168	Dominion Peoples (Inactive)	Unity Twp	40.3073	-79.4371	Inactive
815196	809457	HUNTLEY & HUNTLEY INC/WASHINGTON STATION	Washington Twp	40.4967	-79.6206	Active
605562	629821	PEOPLES NATURAL GAS/MERWIN COMP STA	Washington Twp	40.5083	-79.6203	Active
815203	809466	HUNTLEY & HUNTLEY INC/TARPAY STA	Washington Twp	40.5222	-79.6186	Active
na	na	Mamont (CNX GAS CO/MAMONT COMP STA)	Washington Twp	40.5046	-79.5862	Unkown
741197	735870	CONE MIDSTREAM PARTNERS LP/MAMONT COMP STA	Washington Twp	40.5067	-79.5644	Active

 

Feature image of a compressor station within Loyalsock State Forest, PA. Photo by Brook Lenker, FracTracker Alliance, June 2016.