AMSA Regulatory Alert (RA 04-16)

To: Members & Affiliates, Water Quality Committee
From: National Office
Date: September 1, 2004
Subject: EPA ISSUES REPORT TO CONGRESS ON CSOs AND SSOs
Reference: RA 04-16

On August 26, 2004, the U.S. Environmental Protection Agency (EPA or Agency) released its Report to Congress on the Impacts and Control of Combined and Sanitary Sewer Overflows (Report) (http://cfpub.epa.gov/npdes/cso/cpolicy_report2004.cfm), the second and final report that EPA was required to develop in accordance with the Consolidated Appropriations Act for Fiscal Year 2001. The long-awaited Report, originally due to Congress in December 2003, finds that while there is evidence that “CSOs [combined sewer overflows] and SSOs [sanitary sewer overflows] may cause or contribute to environmental and human health impacts” it is “difficult to establish a cause-and-effect relationship between” human illnesses or water quality impacts/impairments and overflows. The Report provides current estimates of the annual volumes of CSOs and SSOs, a modeled estimate of the number of illnesses caused each year by overflows, and an estimate of the resources that will be needed to further control overflows. The Report also notes that although there is evidence that the occurrence of CSOs and SSOs is widespread, municipal utilities have made significant progress in reducing them.

Although the Report makes no specific policy recommendations, it does provide one of the most comprehensive assessments of sewer overflows in the United States. For CSOs, the Report cites continued progress since EPA’s 2001 Report to Congress, noting the percentage of CSO long-term control plans submitted to permitting authorities has increased from 34 to 59 percent and since issuance of the CSO Control Policy in 1994, CSO volume has dropped from over 1 trillion gallons per year to 850 billion gallons per year. While EPA’s estimate that there are between 23,000 and 75,000 SSOs each year is consistent with earlier estimates, the Agency’s new estimate for the total annual volume of SSOs, three to 10 billion gallons, is two orders of magnitude lower than the 311 billion gallon estimate used in drafting the 2001 SSO Rule proposal.

AMSA has been involved with the effort to develop this Report from the beginning. In August of 2002, AMSA participated in an experts workshop, during which public health experts discussed the potential human health impacts associated with overflows. The following summer, AMSA participated in stakeholder meetings held in Washington, D.C. and California to discuss some of EPA’s preliminary data on the Report. Following those meetings, AMSA wrote EPA’s Assistant Administrator for Water expressing concerns about the validity of key information EPA had presented and to caution the Agency about making national conclusions based on data from a few states, especially with regard to SSOs. For the past year, AMSA has been working with its SSO Workgroup to formulate a potential response to the Report.

EPA’s current Acting Assistant Administrator for Water, Benjamin Grumbles, has already noted in interviews regarding the Report that the information it contains will inform EPA’s internal discussions regarding future Agency activity on SSO issues. AMSA believes the information in the Report, including EPA’s new volume estimate for SSOs, clearly demonstrates that any national policies on SSOs must be flexible enough to balance risk-based, site-specific factors that a one-size-fits-all approach simply cannot accommodate. While EPA’s Report places significant emphasis on looking at all wet weather discharges together on the watershed level, it does not acknowledge that the Agency’s long-standing zero tolerance position towards SSOs is incompatible with such a holistic approach. AMSA continues to advocate for a national SSO policy that mirrors the flexibility of the CSO Control Policy and that can be incorporated into larger, watershed-based control efforts.

Over the coming weeks, AMSA will continue to assess the potential impacts of the Report and consult with its SSO Workgroup and Wet Weather Issues Committee to determine the appropriate next steps. AMSA has reviewed much of the Report’s key chapters and offers the following summary and analysis.

Overview of the Report
The Report consists of an Executive Summary, ten chapters covering each of the major issues Congress asked EPA to address, and thirteen appendices. Chapters 4 through 6 contain the bulk of the key information, though also important are Chapter 7, which discusses EPA’s approach to controlling SSOs, and Chapter 9, which examines the federal, state, and municipal resources spent so far to control overflows and future resources needed to make additional progress. Chapter 10 contains some very generic conclusions and a list of challenges for the future.

Characterization of CSOs and SSOs – Chapter 4
This chapter contains EPA’s estimates for the total number and volume of overflows annually for the entire nation, as well as an overview of the types and quantities of pollutants contained in CSOs and SSOs. EPA appears to have taken to heart comments received during its stakeholder meetings regarding the relative contributions of other waterbody impairment sources. EPA includes a comparison of the volumes of treated wastewater, CSOs, SSOs, and urban stormwater runoff as well as a comparison of the accompanying pollutant loads. Treated wastewater accounts for 51% of all “municipal discharges,” followed closely by urban stormwater runoff at 45%, CSOs at 4% and SSOs at less than 1%.

EPA estimates that the annual CSO volume is approximately 850 billion gallons, down from over 1 trillion gallons prior to the Agency’s issuance of its CSO Control Policy. EPA also estimates that during that same period the number of CSO events has dropped from approximately 60,000 to around 43,000 – a reduction of 28 percent. As a part of developing the Report, EPA also identified latitude and longitude coordinates for more than 90 percent of the CSO outfalls in the U.S. EPA uses this geographical information in subsequent chapters to discuss the potential site-specific impacts of CSOs.

The most telling section of this chapter is the discussion of SSO frequency and volume. Although EPA did not follow the suggestions of many stakeholders to avoid generating national estimates of SSOs based on the data from only 25 states, EPA’s analysis is very revealing. Extrapolating from its database of information from 25 states, EPA estimated that there are between 23,000 and 75,000 SSOs each year in the United States. The annual volume of SSOs for the entire nation was estimated at between three and 10 billion gallons. EPA acknowledges that this analysis, in which they have a much higher degree of confidence, reveals a volume estimate that is two orders of magnitude lower than the 311 billion gallons per year figure it had estimated when developing the draft SSO Rule that would have imposed a zero overflow standard.

Environmental Impacts of CSOs and SSOs – Chapter 5
EPA’s chapter on environmental impacts begins with a statement that impacts from “CSOs and SSOs are often compounded by impacts from other sources of pollution such as storm water runoff, decentralized wastewater treatment systems, and agricultural practices” making it difficult to “assign specific cause-and-effect relationships between CSO and SSO events and observed water quality impacts and impairments.” As with the information EPA presented during its stakeholder meetings, much of this chapter’s water quality-related information is derived from its most recent National Water Quality Inventory (NWQI) report (based on 2000 Section 305(b) data), which EPA notes does not cite CSOs or SSOs as a leading source of impairment in any of the five main waterbody types. Using the latitude/longitude data compiled for CSOs, EPA analyzes potential impacts to 305(b) waters and 303(d) waters (impaired waters list) and later in the chapter to shellfish growing areas.

While EPA finds that between five and ten percent of the waters assessed as impaired are within one mile of a CSO outfall, EPA also notes that CSOs are generally in urban areas that receive high volumes of runoff and other pollutant loads and that waters within these urban areas are more likely to be assessed. For SSOs, where the location of specific overflows is unknown and a similar analysis is impossible, EPA instead looked at SSO impacts by modeling a range of stream flows, different strength (fecal count) wastewater, and varying levels of delivery (how much reaches the stream). Compliance with a single sample maximum (SSM) value for fecal coliform was evaluated. As expected, SSOs consisting of concentrated wastewater are predicted to violate the SSM a majority of the time, particularly in low flow conditions. SSOs consisting of more dilute wastewater are much less likely to cause exceedances of the SSM.

The remainder of Chapter 5 examines the results from several other studies and monitoring programs, including EPA’s Beach Program, the National Marine Debris Monitoring Program, the Ocean Conservancy’s 2003 International Coastal Cleanup, and the NOAA National Shellfish Register, as well as a number of state and local assessments in an attempt to document potential water quality impacts of CSOs and SSOs. In some cases, CSOs and SSOs were directly linked to the observed impacts, as in the case of several fish kills in North Carolina and an incident at Camp Pendleton in California. Beach closure information, including information from the California Beach Closure Report 2000 in which SSOs accounted for 42 percent of the closures, and shellfish harvesting impacts specific to one recent event in Raritan Bay were also cited as evidence that CSOs and SSOs can have environmental impact.

Human Health Impacts of CSOs and SSOs – Chapter 6
This chapter was perhaps the most anticipated section of the Report. During its stakeholder meetings and in earlier discussions, EPA had noted that there was very little data on the health effects of CSOs and SSOs. Stakeholders expressed concerns that EPA would conclude that because CSOs and SSOs contain disease-causing pathogens, there is an assumed direct link to human health impacts. Chapter 5 begins with a clear statement that although “CSOs contain disease-causing pathogens and other pollutants, EPA found limited quantitative evidence of actual human health impacts attributed to specific CSO and SSO events,” making it “difficult to establish a cause-and-effect relationship.”

The chapter starts with a discussion of the types of pollutants contained in CSOs and SSOs that may cause human health impacts, primarily pathogens, but also including toxics, and the various exposure pathways through which a human may come into contact with a CSO or SSO. EPA then outlines the reported human health impacts potentially associated with CSOs and SSOs. EPA primarily examines recreational waters, noting that there were 74 reported waterborne disease outbreaks from 1985 to 2000 (a total of 5,601 cases of illness), though the source of the pathogens in these cases was not identified. For the same time period, there were 191 outbreaks with 14,836 cases of illness reported associated with swimming pools and hot tubs, nearly 265 times the number of illnesses reported for recreational waters.

Lacking comprehensive data to evaluate the number of illnesses caused by CSOs and SSOs, EPA modeled the annual number of illnesses caused by recreational exposure to overflows at a small subset of the nation’s swimming areas (what EPA calls “recognized beaches” from its BEACH Survey, or approximately 9,000 beaches nationwide). The analysis was limited to gastrointestinal illness and estimated the number of illnesses by combining information on the number of exposed swimmer days, the concentration of indicator bacteria to which swimmers are exposed, and the Cabelli/Dufour dose-response functions for marine and fresh waters. EPA’s model (detailed in Appendix J to the Report) found that CSOs and SSOs are estimated to cause between 3,448 and 5,576 gastrointestinal illnesses annually at the “recognized beaches” included in the analysis. EPA does not provide any context for these numbers such as the number of illnesses caused by other water pollution sources (e.g., urban stormwater runoff) or other public health stressors (e.g., food poisoning).

EPA next looks at impacts to drinking water sources, again using the latitude/longitude data for CSO outfalls, but finds that out of only 11 outbreaks accounting for 7,764 illnesses linked to drinking water contamination with sewage, only one of the outbreaks is attributable to CSOs or SSOs, and that CSOs generally do not pose a major risk of contamination to most public drinking water intakes.

The remainder of the chapter examines land-based exposure, which EPA finds of little concern, and occupational exposures, specifically treatment plant workers, noting that comprehensive epidemiological research is lacking in this area. EPA also examines the different demographical groups that may face the greatest risk of exposure to CSOs and SSOs, including people recreating in impacted waters, subsistence fishers, shellfishers, and wastewater workers, and which populations face the greatest risk of illness from exposure to CSOs and SSOs.

Federal and State Efforts to Control CSOs and SSOs – Chapter 7
EPA’s CSO Control Policy and a list of regional and state efforts to control SSOs are outlined in this chapter to illustrate the efforts underway to control overflows. EPA acknowledges that there is no national regulatory program specific to SSOs, and instead highlights the existing standard permit conditions in 40 CFR Part 122.41 that apply to SSOs, including noncompliance reporting, recordkeeping (requiring retention of noncompliance reports), and proper operation and maintenance requirements, which require permittees to properly operate and maintain their collection systems as well as “take all reasonable steps to minimize or prevent SSO discharges.” These conditions, of course, would not apply to satellite collection systems, of which EPA estimates there are more than 4,000, that are not governed by a National Pollutant Discharge Elimination System (NPDES) permit.

Of particular interest in Chapter 7 is a description of North Carolina’s collection system permitting program. The permits contain five principal sections, performance standards, operation and maintenance, inspections, recordkeeping, and general conditions. Systems that fail to meet the standard permit conditions may be subject to enforcement action.

The chapter concludes with an overview of EPA and state enforcement activities including a summary of federal and state enforcement actions concluded against municipalities for CSO- and SSO-related violations.

Resources Spent to Address Impacts of CSOs and SSOs – Chapter 9
Chapter 9 presents a fairly comprehensive history of spending on wastewater infrastructure from early federal funding for CSO control projects in 1965, through the Construction Grants Program (which, according to EPA’s estimates, provided more than $100 billion between 1970 to 1995, peaking in 1977 at $14.1 billion), and finally to the Clean Water State Revolving Fund. EPA estimates that total local and state spending on wastewater infrastructure exceeded $535 billion between 1970 and 2000 and that current capital investment from all public sources is just over $13 billion annually.

Most of the information for this section was pulled directly from EPA’s Clean Water and Drinking Water Infrastructure Gap Analysis and the Clean Water Needs Survey Report to Congress, so these figures are not new. The Report finds that $50.6 billion is needed for CSO control and $88.5 billion to reduce SSOs to one overflow every five years for each system. EPA estimates the gap between project needs and current O&M spending over the next 20 years to be between $72 billion and $229 billion and adds that “if municipalities increase spending at the rate of expected economic growth, the gap largely disappears.”

Conclusions and Future Challenges – Chapter 10
Though EPA makes it clear that they are making no policy recommendations, the Report does lay out some basic findings and actions to be taken to reduce the impacts of overflows. EPA’s mention of the watershed approach, which AMSA believes must be a central component of any efforts to control wet weather overflows, is also noteworthy. No mention is made, however, of the conflict between handling wet weather issues on a watershed basis and the “zero tolerance for overflows” position that EPA enforcement continues to take toward SSOs.

EPA’s Findings

• The occurrence of CSOs and SSOs is widespread. They contain pollutants that are harmful to the environment and human health, and there is evidence that CSOs and SSOs may cause or contribute to environmental and human health impacts.

• CSOs and many SSOs are caused by wet weather conditions and occur at the same time that stormwater and other nonpoint source pollutant loads are delivered to surface waters. This often makes it difficult to directly attribute specific water quality and/or health impacts to CSOs and SSOs. This suggests that a holistic approach should be used to address wet weather impacts, rather than focusing exclusively on sewer overflows.

• There are many existing structural and non-structural technologies that are well-suited for CSO and SSO control. Implementation of emerging technologies and improved information management hold promise for increased effectiveness and efficiency.

• Costs associated with the technologies for controlling CSOs and SSOs are often substantial. Planning is needed to spread costs over time, as appropriate, in developing comprehensive, long-term programs.

To address the future challenges identified in the Report, EPA highlights the importance of protecting our existing infrastructure through proper operation and maintenance, evaluating the impacts of CSOs and SSOs at the watershed level, improving monitoring and reporting, and fostering more and expanded cooperative relationships between federal, state, and local agencies, as well as other clean water stakeholders.