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  • Writer's pictureMark Gruber

What's Up with the Surge in HRA Requests?

Has your facility been asked to prepare a health risk analysis recently? In the last few years California has experienced a wave of Toxic Emission Inventory Plans and Reports (TEIP and TEIR), and Health Risk Assessment (HRA) requests. You may be wondering what happened, and why all the new requirements?

Well, the requirements really aren’t new. The Air Toxics Hot Spots Program has been around since the 1980’s in California. Air Districts take facilities’ reported emissions, run them through a screening model, and most facilities would screen out of any further review. But in 2015 the Office of Environmental Health Hazard Assessment (OEHHA) updated the guidance on how to determine cancer risk, with the most noteworthy change incorporating age sensitivity factors that dramatically affected the estimated cancer risk in residential receptors. As quadrennial (i.e., every four years) toxic emission inventory reports started coming in, there has been a large increase in the number of facilities whose toxic air pollutant emissions, though similar to previous years, now are triggering a detailed toxic emissions review.

Since 2015, numerous facilities who had been reporting their toxic air emissions for years, suddenly were asked to submit a Toxic Emission Inventory Plan (TEIP), followed by a Toxic Emission Inventory Report (TEIR), and potentially a Health Risk Assessment (HRA). Some of these facilities were even asked to bypass the TEIP/TEIR step and go straight to the HRA. ALG has prepared TEIPs, TEIRs, and HRAs for a number of facilities and can help you if you are asked to prepare these documents. In the event the HRA results trigger public notice and/or risk reduction measures, ALG can help identify ways to reduce risk in the most efficient manner.

Interestingly, the main culprit in the reported emission inventory that drives the TEIP/TEIR/HRA requirement is often exhaust from diesel engines. Diesel particulate matter (DPM), the surrogate used by OEHHA for the numerous toxic chemicals in diesel engine exhaust, has a high cancer potency and can be the largest source of cancer risk from a facility. Even for large oil and gas and manufacturing facilities, the main source of cancer risk can be DPM from old Tier 0 diesel fired emergency fire pumps and backup generators, or diesel engines used by contractors performing maintenance or construction projects onsite. And for smaller facilities, a single Tier 0 diesel engine, even used sparingly, can be enough to require at least a TEIP and a TEIR. If you are responsible for reporting toxic emissions, be sure you are using the correct DPM emission factors. If your facility operates Tier 3 and Tier 4 engines and your DPM emissions are calculated based on default uncontrolled PM emission factors, you could be overestimating DPM emissions tenfold or more.

If you would like to learn more about our services in this area, contact Mark Gruber at or at (805) 764-6015.

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