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SJVAPCD Adopts Stricter Health Risk Calculation Methods; Strives To Avoid Unnecessary Barriers to Development

The San Joaquin Valley Air Pollution Control District (SJVAPCD, or “District”) has adopted changes to the methodology it uses to assess health risks from development projects’ air pollution emissions, and the thresholds it uses to determine whether such projects’ cancer risk is “significant” under the California Environmental Quality Act, or CEQA.

These changes, which increase the likelihood of finding any given project to have a significant health risk impact, are based upon recent revisions to the state Office of Environmental Health Hazard Assessment’s (OEHHA’s) Guidance Manual for Preparation of Health Risk Assessments (“Guidance Manual”), and may provide insight into how other local “Air Districts” around the state will incorporate OEHHA’s new advice. Because the Air Districts issue permits to “stationary sources” of air pollution, and because their health risk thresholds are often followed by other local agencies in preparing Environmental Impact Reports under CEQA, adoption of stricter health risk assessment practices by Air Districts could lead to an increase in the number of projects determined to pose significant health risk impacts to the environment.

OEHHA’s revisions to its Guidance Manual were primarily designed to ensure that the greater sensitivity of children to cancer and other health risks is reflected in Health Risk Analyses (HRAs), as required under California’s Children’s Environmental Health Protection Act. For example, OEHHA now recommends that risks be analyzed separately for multiple age groups, focusing especially on young children and teenagers, rather than the past practice of analyzing risks to the general population, without distinction by age. OEHHA also now recommends that statistical “age sensitivity factors” be incorporated into Health Risk Analyses, and that children’s relatively high breathing rates be accounted for. These revisions, compared with the former methodology, would greatly increase the calculated health risk levels for any given project.

On the other hand, the Guidance Manual revisions also include some changes that would reduce calculated health risks. For example, under the former guidance, OEHHA recommended that residential cancer risks be assessed by assuming 70 years of exposure at a residential receptor; under the revised guidance, this assumption is lessened to 30 years. The recommendation for assumed years of worker exposure was also reduced, to 25 years from the former 40. Overall, however, initial assessments indicate that the revisions to the Guidance Manual, if followed, would more than double the calculated health risks, for identical projects. This increase in calculated risk, in turn, has the potential to result in significant delay or even prevent permitting of many common types of projects, notably gas stations, hospital emergency engines, and automotive body shops.

Apprised in advance of the Guidance Manual revisions, the SJVAPCD’s Governing Board in 2013 requested its staff for advice on how to incorporate all proposed additional protections of children and avoid any relaxation of existing health protections, yet at the same time avoid unreasonable restrictions on project permitting. After careful consideration, the District decided to adopt some OEHHA recommendations (e.g., use of “age groups” and factoring in of age sensitivity factors and children’s breathing rates) while retaining the existing, more “conservative” standards for assumed years of residential and worker exposure (70 and 40 years, respectively). These changes, which would increase the likelihood of finding significant health risks by as much as three-fold, were balanced by a change to the District’s recommended CEQA threshold: Formerly, a project would be found to have a significant impact if it would cause a cancer risk rate of 10 in a million;under the new SJVAPCD threshold, that threshold would rise to 20 in a million. The District expects that these changes will result in substantially improved health protections to children and the general population, without excessively chilling approval of development projects with air pollution effects.