The 130th Annual Meeting of APHA

Abstract #35148

Jeffrey Soller, MS¹, Adam Olivieri, Dr PH¹, Robert Spear, PhD², and Don Dodge³. (1) EOA, Inc., 1410 Jackson St., Oakland, CA 94612, 510.832.2852, jasoller@eoainc.com, (2) University of California, at Berkeley, 140 Warren Hall, Berkeley, CA 94720, (3) City of Stockton, 2500 Navy Drive, Stockton, CA 95206

The City of Stockton, California operates a regional wastewater control facility (RWCF) that discharges treated effluent into the San Joaquin River, which is also used by the public for recreational purposes such as swimming, boating, and water skiing. The primary public health risk from exposure to treated wastewater is to enteric viruses. Investigations were carried out between 1996 and 2000 to characterize the estimated level of public health risk associated with enteric viruses that is attributable to the RWCF discharge. A secondary objective was to characterize how additional treatment processes at the RWCF could affect the attributable level of public health risk in the population.

A dynamic, population based model of waterborne disease transmission was developed and implemented in conjunction with a hydrodynamic water quality model. The disease transmission model tracks over time, the number of individuals in relevant epidemiological states based on water quality and population exposure data. This modeling approach provides a transparent structure to incorporate clinical, dose-response, and exposure data into the modeling process. The results of the investigation indicate that the public health risk from enteric viruses that is attributable to the RWCF from recreational activities in the San Joaquin River are well below the risk levels considered tolerable by USEPA for recreation in freshwaters. Moreover, the methodologies employed during these investigations are widely applicable for assessing the public health risk associated with exposure to waterborne microbiological contaminants.

Learning Objectives: Attendess will be introduced to an innovative approach for assessing the public health risk associated with exposure to waterborne microbial pathogens. Participants will acquire an understanding of quantitative microbial risk assessment. At the conclusion of the session, the participant in this session will be able to

• Articulate the primary public health risk from recreational exposure to treated wastewater;
• Describe how epidemiological status of the population is related to risk; and
• Assess watershed based risk management considerations in terms of attributable risk

Keywords: Statistics, Epidemiology

Presenting author's disclosure statement:
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.