Do air emissions from compressor stations pose serious health risks?

1. Do air emissions from compressor stations pose serious health risks? • Pipeline Safety Trust Conference • November 21, 2008 • Chris Nidel, MS, JD

2. Serious? Risk? • serious|ˈsi(ə)rēəs| adjective • 1 (of a person) solemn or thoughtful in character or manner : her face grew serious. • • (of a subject, state, or activity) demanding careful consideration or application : marriage is a serious matter. • • (of thought or discussion) careful or profound : we give serious consideration to safety recommendations. • • (of music, literature, or other art forms) requiring deep reflection and inviting a considered response : he bridges the gap between serious and popular music. • 2 acting or speaking sincerely and in earnest, rather than in a joking or halfhearted manner : suddenly he wasn't teasing any more—he was deadly serious | actors who are serious about their work. • 3 significant or worrying because of possible danger or risk; not slight or negligible : she escaped serious injury. • risk |risk|noun • a situation involving exposure to danger • the possibility that something unpleasant or unwelcome will happen

3. Air Emissions of Concern • Formaldehyde - Reasonably anticipated to be a human carcinogen (NTP), genotoxic • Acetaldehyde - Reasonably anticipated to be a carcinogen (NTP), genotoxic • Acrolein - weakly positive for genotoxic assays • PM - respiratory toxicant, cardiac disease • NOx, Methane, CO, CO2, - asthma, secondary particulates, greenhouse gases, etc.

4. Dose Makes the Poison? • General premise of toxicology that the dose makes the poison • The idea is that many things are toxic at some dose • However, not all doses of toxic substances have toxic effect

5. Poison Makes the Dose? • How general is the general premise? • Very little is known about synergistic and compound exposures. • Children and other populations may be significantly more susceptible to exposures at the same dose • Exposures to genotoxic compounds do not play by the rules

6. Cancer, Genotoxins, and No-threshold Effects • Genotoxicity is the presumed mechanism of many carcinogens • Theoretically, one molecule of a genotoxic compound (e.g. formaldehyde, acetaldehyde) can cause a mutation --> leading to cancer • This theoretical possibility leads to the conclusion that there is no “safe” exposure to genotoxins or carcinogens • This means that any exposure creates cancer risk

7. Compressor Station

8. Transco 130 - Comer, GA • “Actual” emissions estimated using emissions factors from the EPA

9. Emissions Estimates for Compressor Station • NOx, CO, and total hydrocarbon (THC) emissions based on testing done in the early 1990’s. • VOC component of the THC estimated by EPA database, approximated at 9.31% • The “actual” emissions for specific VOCs then estimated using the EPA AP-42 emissions factors

10. Emissions Estimates for Compressor Station • NOx, CO, and total hydrocarbon (THC) emissions subject to uncertainty • Testing is ~15 years old • No information regarding overhaul status or age of equipment at testing vs. current performance • VOCs not tested directly • EPA’s SPECIATE database is subject to uncertainty in converting THC to VOCs • AP-42 Emissions factors used to get individual VOC emissions is limited and may significantly underestimate actual emissions

11. Compressor Age at Transco Station 130

12. AP-42 and Uncertainty • Canadian study looked at emission from a petroleum refinery • Direct testing of emissions using laser based “DIAL” testing • Generated an emissions inventory for facility operations and compared to inventory based on AP-42 estimates • DIAL measurements showed actual VOC emissions almost 15X AP-42 estimates • Dial measurements showed actual benzene emissions 18X AP-42 estimates

13. Emissions vs. Exposure • Emissions estimates in tons/year need to be translated into concentrations such as ppm, ppb, or ug/m3 • This is typically done using an air disperson model

14. Air Dispersion Modeling • Resulting model is only as good as the inputs, remember, garbage in equals garbage out • The emission rates of the pollutants of concern are the most important inputs to the model for its accuracy • Also dependent on climatological variables, wind speeds and direction, temperatures, and pressures

15. What We Don’t Know About the Health Risk • Uncertainty in actual emissions from facility • AP-42 may significantly underestimate or mischaracterize the actual emissions • Transco test data may not be representative of current emissions • TPH emissions may not be accurately represented by the EPA database • No estimates of exposure or dose information from an air dispersion model or equivalent • No understanding of individual susceptibilities downwind of the station • No appreciable understanding of synergistic or compound risk from multiple exposures

16. What We DO Know About the Health Risk • Cancer risk begins even at low exposures • Cancer risk for children is estimated at 10-100X the risk for adults at the same exposure • Respiratory and other effects of exposure to these VOCs may occur at low exposures (e.g. formaldehyde effects in FEMA trailers) • Formaldehyde, acetaldehyde, and benzene (carcinogens or reasonably anticipated to be) are released in significant quantities • PM and greenhouse gases present both regional and global health risks

17. Is There a Serious Health Risk? • There certainly is some risk based on what is known. • How serious is that risk? • We need a better understanding of the uncertainties that we have identified before we can qualify or quantify the risk • Should start with improving our understanding of the actual emissions rates • And then use these inputs in an air dispersion model

18. Without Knowing What the Risk Is... • The surrounding public should not be subjected to the industry’s experiment - the industry should bear the burden of showing that there is no risk. • Currently regulations require almost no control on these emissions - permits merely report emissions • older and higher polluting equipment is effectively grandfathered - similar to coal-fired power plants • Significant improvements in emissions could be achieved by installing new compressors and: • Selective Catalytic Reduction (SCRs) - to reduce NOx emissions • Catalytic oxidation equipment to reduce carbon monoxide emissions (yielding more CO2 however)

19. Conclusions • Hazardous emissions from compressor stations have been largely overlooked by current regulations • Regulatory programs must be improved to address the “loophole” • Short of regulatory programs, pipeline operators should take steps to minimize the threat to neighboring populations as well as the regional and global environment by: • better understanding emissions and associated risks • upgrading to modern compressors with control equipment • increasing the use of engineering controls, such as enclosing compressor facilities and treating or scrubbing compressor emissions