Publication Detail
Proposed State Route 125 South Air Emissions and the Sweetwater Reservoir: A Review of Recent Reports Sponsored by the Sweetwater Authority
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UCD-ITS-RR-99-09 Research Report |
Suggested Citation:
Eisinger, Douglas, Tom P. Kear, Daniel P. Chang, K. Dougherty, M. Stallard, M. Johnson (1999) Proposed State Route 125 South Air Emissions and the Sweetwater Reservoir: A Review of Recent Reports Sponsored by the Sweetwater Authority. Institute of Transportation Studies, University of California, Davis, Research Report UCD-ITS-RR-99-09
The California Department of Transportation (Caltrans) asked scientists at U.C. Davis (UCD) to review the relationship between proposed SR 125 (including an associated extension of SR 54) and its potential impact on water quality at the Sweetwater Reservoir. Specifically, Caltrans asked UCD to review and comment on two recent studies: "SR 125 South Route Alternatives: Potential Air Emissions Impact on Sweetwater Reservoir (Ogden, 1997a and 1997b)," and "The Impact of SR 125 Vehicle Emissions on the Sweetwater Reservoir, Transport, Environmental Fate, and Cancer Risk Assessment (Byard and Giroux, 1999)." As part of that review, UCD examined health risk estimates in the Sweetwater Authority-sponsored studies that estimated the relationship between SR 125-generated air pollution and health risks to reservoir water users.
In summary, the most important UCD findings follow:
In summary, the most important UCD findings follow:
- 1. Based upon examination of the Sweetwater Authority's consultant reports and additional data collected by UCD, there are no significant health effects that would result from SR 125-generated air emissions depositing onto the Sweetwater Reservoir.
- 2. Both the Ogden report (especially the draft version, Ogden 1997a, as well as the final version, Ogden 1997b) and the Byard report (Byard and Giroux, 1999) include unrealistic assumptions that increase the estimated SR 125-related health risks to Sweetwater Reservoir drinking water users.
- 3. UCD briefly reviewed data from other reservoirs located near highways; the review did not identify any evidence that roadway-related air emissions degrade water quality.
- 4. Regional scale air emissions (Le., emissions from the entire metropolitan region) already affect ambient air concentrations over the reservoir, and contribute hundreds of times more pollutant deposition onto the reservoir than the projected emissions from SR 125. Either there is an existing problem with water quality in the reservoir, or common sense indicates that no measurable problem will result in the future from SR 125.