Tanja Srebotnjak, Public Health Research Fellow, San Francisco
The concerns about air and water pollution resulting from the explosive growth in unconventional oil and gas development using hydraulic fracturing (‘fracking’) and other controversial stimulation methods have received a lot of attention recently. Increased oil and gas production using these new technologies can bring more contaminants—many of which have been linked to respiratory and neurological problems, birth defects, and cancer [1,2]—to backyards, communities, and cities. One type of pollution at oil and gas sites, however, remains woefully under-studied contrary to its public health significance: noise.
Environmental noise caused by oil and gas drilling activities is often overlooked entirely or rejected as a minor, temporary nuisance by industry and regulators alike – despite the fact that drilling and other activities at well sites are very noisy and can be close to homes. In fact, public health experts have identified noise as a ubiquitous health threat for communities near oil and gas development sites and studies have found noise levels above safety thresholds [3,4]. They note that insufficient steps have been taken to reduce noise levels in impacted communities. So why isn’t there more noise about noise?
What is environmental noise?
Simply stated, environmental noise relates to the summary of ambient sound that people perceive as unwanted. It includes noise from traffic, construction, industrial and even some recreational activities. What makes sound unwanted depends on environmental factors (e.g., urban versus rural) and time of day. Generally speaking, sound becomes unwanted when it interferes with normal activities such as sleeping, conversation, or diminishes quality of life (see table below for examples of noise impacts).
Noise Source
Decibel level (dBA)*
Impact
EPA guideline values (1974) and OSHA Occupational Noise Exposure Limits
Examples of noise levels measured near oil and gas sites
Breathing
10
Barely audible
Whisper; Rustling leaves
20
About twice as loud as 10 dBA
Quiet room
28-33
About 4 times as loud as 10 dBA
Lowest limit of urban ambient sound; Typical living room; Forced hot air heating system
40-50
Disturbance of sleep patterns ( sleep quality)
45 dBA annual 24 hour average for no interference with indoor activities
New York (2011) 44 to 68 dBA during drilling at 250-2,000 feet
Quiet suburb; Clothes dryer; Printer
50-60
Disturbance of sleep patterns ( awakening and mood impacts)
55 dBA annual 24 hour average for no activity interference outdoors
West Virginia (2013) one-hour noise measurements at several of 7 well pads exceeded 55 dB annual 24 hour average
Conversation in a restaurant; Window Fan on High
60-70
Impacts on school performance
New York (2011) 52 to 75 dBA during well pad construction
Vacuum cleaner
70-80
Ischemic heart disease, hypertension
70 dBA annual 24-hour average lifetime exposure above which hearing loss may occur
Fort Worth (2006) 71-79 dBA drilling noise at 200 feet from well
Freight train at 50 feet; Propeller plane at 1000 feet; Food blender
80-90
Hearing damage possible if exposed for 8 hours or more
90 dbA permissible noise exposure limit for a maximum of 8 hrs per day (OSHA)
New York (2011) 72 to 90 dBA during fracking at 250-2,000 feet
Power mower; Boeing 737 at 6000 feet
90-100
Hearing loss at sustained exposure
Fort Worth (2006) 102 dBA rig generator at 10 feet; New York (2011) up to 102 dBA during fracking at 50-500 feet
Chain saw
120
Pain
115 dBA permissible noise exposure limit for a maximum of 15 min per day (OSHA)
*dBA: decibel A-weighted. A-weighting is applied to instrument-measured sound levels in effort to account for the relative loudness perceived by the human ear, as the ear is less sensitive to low audio frequencies. Sources: West Virginia Department of Environmental Protection, Division of Air Quality, “Air, Noise, and Light Monitoring Results For Assessing Environmental Impacts of Horizontal Gas Well Drilling Operations (ETD‐10 Project),” prepared by Michael McCawley for the West Virginia Department of Environmental Protection, May 3, 2013. Galen Carol Audio, “Decibel (Loudness) Comparison Chart,” www.gcaudio.com/resources/howtos/loudness.html (accessed October 6, 2014); WHO, “Noise Data and Statistics,” www.euro.who.int/en/health-topics/environment-and-health/noise/data-and-statistics (accessed October 22, 2014); Public Health Madison & Dane County, “Potential Health Effects of Noise Exposure,” June, 7, 2013.
Can excessive noise impact health?
Acute and chronic exposure to high levels of noise is associated with serious health risks, including hearing damage and loss, sleep disturbance, stress, reduced school and work performance, headaches, high blood pressure, and other cardiovascular problems. Especially nighttime noise has been found to increase these risks.
Noise is one of the most ubiquitous environmental health problems in the U.S. and other countries [5]. Particularly vulnerable are children, the elderly, the chronically ill, and hearing-impaired individuals. Emerging science also indicates that stress caused by noise can affect the immune system and may be related to birth defects and low birth-weight babies [6,7].
To combat environmental noise, the EPA has specified guideline values of annual 24-hour averages of 45 dB (decibel [8]) indoors and 55 dB in outdoor environments [9]. The agency also states that lifetime exposure (i.e., being exposed continuously for 70 years) to noise above 70 decibels (dB) over a 24-hour period may lead to hearing loss. However, these guideline values are more than 30 years old and do not reflect scientific advances in our understanding of the health impacts of noise. The Occupational Safety and Health Administration (OSHA) – tasked with protecting the health and safety of workers – has developed occupational permissible noise exposure limits that specify the maximum periods of time workers can be exposed to different noise levels. For example, at 90 dBA exposure is limited to a maximum of 8 hours per day, while at 115 dBA exposure duration must be at most 15 minutes.
What is known about noise and unconventional oil and gas development?
Unconventional oil and gas development, including the use of hydraulic fracturing, are industrial processes that generate prolonged periods of noise pollution for workers and nearby communities. Well pad preparation, drilling, and well stimulation generate significant noise levels for neighboring residences, schools, and work places. The noise—from trucks, generators, drilling operations, and pumps—can occur intermittently for days at a time and over several years as wells are hydraulically fractured and reworked many times [10]. The more recent practice of drilling multiple wells per well pad at higher well density can further increase the duration, frequency, and intensity of noise pollution. As a result of the expansion of unconventional oil and gas development into populated areas, a growing number of people are potentially exposed to harmful noise pollution.
At the same time, concerned scientists and community members point to the paucity of measurement data at and near drilling sites. A 2006 study for the City of Fort Worth in Texas found that drilling noise was audible at 700 feet from the wellbore and drilling brakes could still be heard at 1000 feet [11]. The average noise level at 200 feet was between 71-79 dBA. The loudest noise at 102 dBA, measured at 10 feet, was caused by rig generators. In West Virginia researchers studied noise levels at seven well pads during site clearing and preparation, vertical drilling, horizontal drilling, hydraulic fracturing, and flowback operations. Some of the one-hour noise measurements taken exceeded EPA’s guideline annual average daily exposure value of 55 dBA and local noise limits for Jefferson County, WV and the city of Morgantown, WV [12]. The State of Maryland in its Health Impact Assessment of potential Marcellus shale gas development [13] expects increased noise levels during all phases of well development and production. New York State’s 2011 draft Supplemental Generic Environmental Impact Statement [14] on the proposed regulations regarding high-volume hydraulic fracturing estimated that noise levels would range from 52 to 75 dBA during well pad construction, 44 to 68 dBA during drilling, and 72 to 90 dBA during high volume hydraulic fracturing – all at a distance of 250-2,000 feet. At 50 to 500 feet, hydraulic fracturing noise could reach 102 dBA.
These studies show that noise from unconventional oil and gas development poses real risks to the health and wellbeing of the people and communities impacted by it.
Regulating noise
Although Congress in 1972 passed the Noise Control Act to regulate major sources of noise, including from transportation vehicles and equipment, machinery, and appliances, noise control has fallen behind scientific knowledge on the health impacts of environmental noise and the growth in population and economic activity. In addition to outdated federal and state protections, the oil and gas industry also managed to carve out exemptions from several sections of the Occupational Safety and Health Administration’s noise standards, which also leaves oil and gas workers potentially exposed to unhealthy levels of noise every day [15].
Left with a vacuum of federal action, some states and municipalities with intense drilling activities have begun to address noise concerns by setting or increasing setback distances and noise limits. Colorado, for example, specified maximum permissible noise levels according to zoning districts and time of day in 2013. These range from a low end of 50 dBA for nighttime noise in residential/agricultural/rural zones to 80 dBA for daytime noise industrial zones [16]. The 2012 Pennsylvania Oil and Gas Act requires that compressor stations and natural gas processing plants do not exceed 60 dBA at the nearest property line or the applicable Federal law (whichever is less). The City of Fort Worth, TX ordained a 600 feet setback distance of oil and gas wells to ‘Protected Land Uses,’ including residences, religious institutions, hospital buildings, schools, and public parks. The city also set maximum permissible noise levels on a sliding scale according to process stage and time of day, and requires operators to submit noise management plans as part of its drilling permit applications [17].
These are important first steps towards protecting communities from oil and gas related noise pollution, but more needs to be done, including using the best available science to set maximum permissible noise levels and to extend them to all regions with current and potential future unconventional oil and gas development.
What should be done?
In order to expand and strengthen noise standards and to bring relief to impacted communities, in particular the most vulnerable population groups, we need:
Assessments of the health impacts of noise at and near oil and gas development, including fracking,
Research into characterizing noise pollution in the vicinity of unconventional oil and gas well sites in terms of its sources, intensities, frequencies, and duration,
Increase noise monitoring at and near unconventional oil and gas development sites,
Adequate setback distances to minimize noise impacts on communities affected by oil and gas development,
Federal assessment and regulations of noise need to be updated to reflect current research and increased threats from expanding sectors, like oil and gas,
Strengthened state and local laws and ordinances requiring operators to submit noise management plans with their drilling permit applications.
References
[1] John L. Adgate, Bernard D. Goldstein, Lisa M. McKenzie, “Potential Public Health Hazards, Exposures and Health Effects from Unconventional Natural Gas Development,” Environmental Science & Technology, February 2014, doi:10.1021/es404621d.
[2] Lisa M. McKenzie et al., “Birth Outcomes and Maternal Residential Proximity to Natural Gas Development in Rural Colorado,” Environmental Health Perspectives, 2014, doi:http://dx.doi. org/10.1289/ehp.1306722.
[3] Maryland Institute for Applied Environmental Health, “Potential Public Health Impacts of Natural Gas Development and Production in the Marcellus Shale in Western Maryland,” University of Maryland, School of Public Health, 2014.
[4] Roxana Z. Witter, et al., “Health Impact Assessment for Battlement Mesa, Garfield County Colorado,” www.garfield-county.com/public-health/documents/1%20%20%20Complete%20HIA%20without%20Appendix%20D.pdf, 2010.
[5] Hänninen, Otto, Anne B. Knol, Matti Jantunen, Tek-Ang Lim, André Conrad, Marianne Rappolder, Paolo Carrer et al. "Environmental burden of disease in Europe: assessing nine risk factors in six countries." Environ Health Perspect 122, no. 5 (2014): 439-446.
[6] Passchier-Vermeer W, Passchier WF (2000) Noise Exposure and Public Health. Environmental Health Perspectives 108 Suppl:123–31.
[7] K.I. Hume, M. Brink, M. Basner, “Effects of environmental noise on sleep,” Noise Health, 14(61):297‐302 (2012).
[8] The decibel (dB) is a logarithmic unit used to express the ratio between two values of a physical quantity, often power or intensity. As the human ear can detect sounds with a wide range of amplitudes, sound pressure is often measured as a level on a logarithmic decibel scale.
[9] EPA, “EPA Identifies Noise Levels Affecting Health and Welfare,” http://www2.epa.gov/aboutepa/epa-identifies-noise-levels-affecting-health-and-welfare (accessed September 26, 2014).
[10] Alan Krupnick, Hal Gordon, Sheila Olmstead, “Pathways to Dialogue: What the Experts Say about the Environmental Risks of Shale Gas Development,” Resources for the Future, 2013.
[11] Behrens and Associates, “Gas Well Drilling Noise Impact and Mitigation Study,” study commissioned by the City of Fort Worth, TX, 2006.
[12] West Virginia Department of Environmental Protection, Division of Air Quality, “Air, Noise, and Light Monitoring Results For Assessing Environmental Impacts of Horizontal Gas Well Drilling Operations (ETD‐10 Project),” prepared by Michael McCawley for the West Virginia Department of Environmental Protection, May 3, 2013.
[13] Ibid. [3].
[14] New York State Department of Environmental Conservation, “Revised Draft SGEIS on the Oil, Gas and Solution Mining Regulatory Program, Well Permit Issuance for Horizontal Drilling and High-Volume Hydraulic Fracturing in the Marcellus Shale and Other Low-Permeability Gas Reservoirs,” September 2011, http://www.dec.ny.gov/energy/75370.html (accessed October 6, 2014).
[15] Roxana Z. Witter, et al., “Occupational Exposures in the Oil and Gas Extraction Industry: State of the Science and Research Recommendations,” American Journal of Industrial Medicine, March. doi:10.1002/ajim.22316, 2014.
[16] Colorado Oil and Gas Conservation Commission, “Aesthetic and Noise Control Rules,” Series 800, 2013, https://cogcc.state.co.us/RR_Docs_new/rules/800series.pdf (accessed October 6, 2014).
[17] City of Fort Worth, “ORDINANCE NO. 18449-02-2009,” An Ordinance amending the Code of Ordinances of the City of Fort Worth, by amending Article II of Chapter 15, “Gas” entitled, “Gas Drilling and Production,” regulating drilling and production of gas wells within the city to provide revised regulations regarding distance, noise, gas pipelines, and technical provisions. City of Fort Worth, 2009.