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Regulatory Alert - RA 03-07 - DATA NEEDED FOR PATHOGEN STUDY

Member Pipeline - Regulatory - Alert (RA 03-07)

To: Members & Affiliates, Wet Weather Issues Committee
From: National Office
Date: June 27, 2003
Subject: DATA NEEDED FOR PATHOGEN STUDY
Reference: RA 03-07

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Action Please By:
July 11, 2003

The Association of Metropolitan Sewerage Agencies’ (AMSA) newly formed Pathogens Workgroup has begun an effort to characterize, to the extent feasible, the potential adverse human health effects that may be associated with human exposure to pathogenic microorganisms through combined and sanitary sewer overflows (CSOs and SSOs). AMSA hopes to complete the initial phase of the project over the next few months in order to use the results as a key component of the Association’s response to the U.S. Environmental Protection Agency’s (EPA) Report to Congress on the impacts and controls of CSOs and SSOs, due this December. While in subsequent phases of the project AMSA plans to collect new data on pathogen concentrations in wet weather flows, the timing of EPA’s Report to Congress will require the use of existing data for this initial phase.

To meet this schedule, AMSA asks that any member agency or affiliate that has access to any of the following data contact Chris Hornback, AMSA’s Director of Regulatory Affairs at 202/833-9106 or chornback@amsa-cleanwater.org by July 11, 2003:

Concentrations of pathogens¹ in raw wastewater, primary effluent, and unchlorinated and chlorinated secondary effluent, and a description of the associated treatment;
Concentrations of pathogens in urban runoff and/or receiving waters;
Actual or representative ranges of dilution that feasibly occur or have occurred (with storm water and/or receiving waters) during specific CSO and/or SSO events;
Actual or representative ranges of the number of individuals that potentially are/were exposed to CSO and/or SSO events;
Actual and/or representative estimates of the number (or frequency) and duration of CSO and/or SSO events that occur annually in a given jurisdiction (town, city, county, state, etc.).

Project Background
EPA’s initial research indicated that little data were available that linked waterborne illness or other exposures to CSOs and SSOs. To assist in understanding the factors that complicate the collection of information and data to characterize the potential adverse human health effects associated with exposure to pathogens via CSOs and SSOs, EPA held an experts workshop in August 2002 on the public health impacts of sewer overflows. During this workshop there was general agreement on the specific pathogens of concern, the illnesses that are associated with those pathogens, which pathogens produce the most serious illnesses, the myriad of exposure pathways, and the sensitive subpopulations of most concern. There was not, however, agreement with respect to the relative importance of CSOs and SSOs compared to the array of pathogens that the public faces on a daily basis.

More recently, a stakeholder meeting held in Washington, D.C. June 24 and 25, to discuss EPA’s progress to date on developing its Report to Congress, revealed that the Agency has relied primarily on indicators such as fecal coliform and E. coli to characterize pathogen levels in wet weather flows, and has collected little information on the relative risk associated with CSOs and SSOs compared to other pathogen exposures.

AMSA, in collaboration with its contractor EOA Inc., will develop information related to and characterize, to the extent feasible, the potential adverse human health effects that may be associated with human exposure to pathogenic microorganisms through CSOs and SSOs. The investigation will encompass the critical factors associated with characterizing the potential public health risk associated with exposure to pathogens via CSOs and SSOs, including representative ranges for concentrations of pathogens in treated and untreated wastewater, dilution of wastewater during CSO and SSO events, volume of wastewater the public may be exposed to during CSO and SSO events, pathogen infectivity, and number of individuals exposed. The intent of the investigation is to demonstrate how the data may be used to characterize the expected level of public health risk/concern associated with a CSO or SSO event and to identify the types of CSO and/or SSO events that may present less concern from a public health perspective.

Again, please contact Chris Hornback, AMSA’s Director of Regulatory Affairs at 202/833-9106 or chornback@amsa-cleanwater.org with relevant information relating to the data categories discussed above or with any questions or concerns regarding this project.

¹ AMSA would be interested in pathogenic bacteria (salmonella, shigella, Camplyobacter, E. Coli 0157:H7, etc), parasites (giardia lamblia, cryptosporidium parvum, Entamoeba histolytica, etc.), total culturable virus, and human enteric viruses (Adenoviruses, Rotavirus, etc.). Bacterial indicator data (total & fecal coliform, eterococcus) are not of particular interest.