Chapter 6

Human Health Impacts of CSOs and SSOs In this chapter: 6.1 What Pollutants in CSOs n addition to causing and This chapter documents and expands and SSOs Can Cause contributing to the environmental the current understanding of human Human Health Impacts? impacts reported in Chapter health impacts from CSOs and I 6.2 What Exposure Pathways 5, CSOs and SSOs can cause or SSOs. The chapter first describes contribute to human health impacts. the pollutants commonly present in and Reported Human Health Impacts are Microbial and toxics can CSOs and SSOs that can cause human Associated with CSOs and be present in CSOs and SSOs at levels health impacts. The next sections SSOs? that pose a risk to human health. discuss human exposure pathways; Human health impacts occur when demographic groups and populations 6.3 Which Demographic people become ill due to contact that face the greatest exposure and Groups Face the Greatest with or ingestion of water or shellfish risk of illness; and ways in which Risk of Exposure to CSOs and SSOs? that have been contaminated with human health impacts from CSOs and microbial pathogens or toxics. SSOs are communicated, mitigated, 6.4 Which Populations Face or prevented. The identification and the Greatest Risk of Illness Although it is clear that CSOs tracking of illnesses associated with from Exposure to the and SSOs contain -causing CSOs and SSOs are also discussed. Pollutants Present in CSOs pathogens and other pollutants, EPA Several examples of human health and SSOs? found limited quantitative evidence impacts are provided in the chapter. 6.5 How are Human Health of actual human health impacts Impacts from CSOs and attributed to specific CSO and SSOs, Communicated, SSO events. Factors such as under- 6.1 What Pollutants in CSOs Mitigated, or Prevented? reporting and incomplete tracking and SSOs Can Cause 6.6 What Factors Contribute of waterborne illness, the presence of Human Health Impacts? pollutants from other sources, and to Information Gaps in Identifying and Tracking the use of non-pathogenic indicator he principal pollutants present Human Health Impacts in CSOs and SSOs that can bacteria in water quality monitoring from CSOs and SSOs? often make it difficult to establish a Tcause human health impacts cause-and-effect relationship between are microbial pathogens and toxics. 6.7 What New Assessments human illnesses and CSO and SSO The presence of biologically active and Investigative Activities discharges. chemicals (e.g., , hormones, are Underway?

6-1 Report to Congress on the Impacts and Control of CSOs and SSOs

and steroids) is also a concern but is indicators include total coliform, fecal less well understood at this time. coliform, E. coli, and enterococci. Further discussion of bacterial 6.1.1 Microbial Pathogens indicators is provided in Section 6.6.

Microbial pathogens include hundreds Pathogenic bacteria are also common of different types of bacteria, , in human waste and are capable and parasites. Microbial pathogens of causing disease. Human health of human and non-human origin are impacts from pathogenic bacteria present in domestic and industrial most often involve gastrointestinal wastewater. The presence of specific illnesses. The predominant symptoms microbial pathogens in wastewater of pathogenic bacterial depends on what is or include abdominal cramps, diarrhea, in the local community and , and vomiting. Pathogenic is often transient. Some microbial bacteria can also cause such pathogens also have environmental as , although this is sources. In general, microbial not common in the United States. pathogens are easily transported In addition to attacking the human by water. They can cause disease in digestive tract, the pathogenic bacteria aquatic biota and illness or even death present in CSOs and SSOs can in humans. The three major categories cause illnesses such as pneumonia, of microbial pathogens present in bronchitis, and swimmer’s ear. CSOs and SSOs are bacteria, viruses, Common pathogenic bacteria, typical and parasites. Fungi do not have a concentrations present in sewage major presence in wastewater (WERF (where available), and associated 2003b), and thus in CSOs and SSOs. disease and effects are summarized in Table 6.1. Bacteria Bacteria are microscopic, unicelluar Viruses organisms. Two broad categories Viruses are submicroscopic infectious of bacteria are associated with agents that require a in which wastewater: indicator bacteria and to reproduce. Once inside the host, pathogenic bacteria. Indicator bacteria the reproduces and manifests are common in human waste and in illness (EPA 1999c). More than are relatively easy to detect in water, 120 enteric viruses are found in but they are not necessarily harmful sewage (NAS 1993). The predominant themselves. Their presence is used symptoms resulting from enteric virus to indicate the likely presence of include vomiting, diarrhea, disease-causing, fecal-borne microbial skin rash, fever, and respiratory pathogens that are more difficult to infection. Most waterborne and detect. Enteric (intestinal) bacteria seafood-borne diseases throughout have been used for more than 100 the world are caused by viruses (NAS years as indicators of the presence 2000). Many enteric viruses, however, of human feces in water and overall cause infections that are difficult to microbial water quality (NAS 1993). detect (Bitton 1999). A list of common Enteric bacteria commonly used as enteric viruses, including typical

6-2 Chapter 6—Human Health Impacts of CSOs and SSOs

Bacteria Concentration Diseaseb Effectsb Infective Dosec,d in Sewagea Table 6.1 (per 100mL) Common Pathogenic Campylo- 3,700 -100,000 Gastroenteritis Vomiting, diarrhea 102 - 106 Bacteria Present in bacter Sewage Pathogenic 30,000 - Gastroenteritis Vomiting, diarrhea, 106 - 108 E. coli 10,000,000 Hemolytic Uremic Infective dose is defined as the syndrome (HUS), number of pathogens required to death in susceptible cause subclinical infection. Infective populations doses are typically given as ranges, 0.2 - 11,000 Salmonellosis Diarrhea, dehydration 104 - 107 as the actual infective dose depends S. typhi Typhoid fever High fever, diarrhea, 103 - 107 on the strain and an ulceration of the small individual’s health condition. intestine Shigella 0.1 - 1,000 Shigellosis Bacillary dysentery 101 - 102 Vibrio Cholera Extremely heavy 103 - 108 cholera diarrhea, dehydration Vibrio non- 10 - 10,000 Gastroenteritis Extremely heavy 102 - 106 cholera diarrhea, nausea, vomiting Yersinia Yersinosis Diarrhea 106 a Details in Appendix I c Yates and Gerba 1998 b EPA 1999C d Lue-Hing 2003 concentrations present in sewage Parasites (where available), and associated Parasites by definition are animals or disease and effects are summarized plants that live in and obtain nutrients in Table 6.2. Infective doses are not from a host organism of another reported; enteric viruses typically are species. The parasites in wastewater very infectious. that pose a primary public health

Table 6.2 Virus Group Concentration Diseaseb Effects b in Sewagea Common Enteric Viruses (per 100mL) Present in Sewage Adenovirus 10 - 10,000 Respiratory disease, Various effects gastroenteritis, Enteric viruses are typically very pneumonia infectious: 1-10 virus particles can cause infection. Astrovirus Gastroenteritis Vomiting, diarrhea Noraviruses (includes Gastroenteritis Vomiting, diarrhea Norwalk-like viruses) Echovirus Hepatitis, respiratory Various effects, infection, aseptic including liver disease Enterovirus (includes 0.05 - 100,000 Gastroenteritis, Various effects , encephalitis, heart anomalies, aseptic conjunctivitis, and meningitis, polio coxsackie viruses) Reovirus 0.1 - 125 Gastroenteritis Vomiting, diarrhea Rotavirus 0.1 - 85,000 Gastroenteritis Vomiting, diarrhea

a Details in Appendix I c Yates and Gerba 1998 b EPA 1999C d Lue-Hing 2003

6-3 Report to Congress on the Impacts and Control of CSOs and SSOs

concern are protozoa and helminths Indicator Bacteria and Microbial (NAS 1993). Parasitic protozoa Pathogens in Sewage commonly present in sewage include Microbial pathogen concentrations Giardia lamblia, Cryptosporidium in sewage vary greatly depending on parvum, and Entamoeba histolytica. the amount of illness and infection in These protozoa cause acute and the community served by the sewer chronic diarrhea (NAS 1993). Giardia system. The time of year can also causes giardiasis, which is one of the be important, as some outbreaks of most prevalent in viral disease are seasonal. Average the United States (EPA 2001e). concentrations of indicator bacteria (e.g., fecal coliform) and other Ranges of typical concentrations of microbial pathogens (enteric viruses protozoa in sewage and information and protozoan parasites) shed by on infective doses are summarized an infected person are shown in in Table 6.3. As shown, ingestion of Table 6.4. These high concentrations a small number of parasitic protozoa illustrate that a single person shedding is capable of initiating infection. pathogenic organisms can cause a Therefore, the presence of low levels large pathogen load to be discharged of parasitic protozoa in wastewater to a municipal sewer system. is a greater health concern than are low levels of most pathogenic bacteria 6.1.2 Toxics (NAS 1993). As described in Section 4.1 of this Helminths, or parasitic worms, include report, toxics are chemicals or roundworms, hookworms, tapeworms, chemical mixtures that, under certain and whipworms. These organisms are circumstances of exposure, pose a endemic in areas lacking adequate risk to human health. Individuals can hygiene. Very little documentation of suffer chronic health effects resulting waterborne of helminth from prolonged periods of ingestion infection is available (NAS 1993). or consumption of water, fish, and Helminth infections can be difficult to shellfish contaminated with a toxic diagnose and often exhibit no obvious substance. Generally, metals and symptoms. synthetic organic chemicals are the

Table 6.3 Parasitic Concentration Diseaseb Effectsb Infective Dosec Protozoa in Sewagea Common Parasitic Protozoa Present in (per L) Sewage Cryptosporidium 3 - 13,700 Crypto- Diarrhea 1 - 150 sporidiosis Parasitic protozoa have very low Entamoeba 4 - 52 Amedbiasis Prolonged diarrhea 10 - 20 infective doses, which makes their (amoebic with bleeding, abscess presence in CSO and SSO discharges dysentery) of the liver and small intestine an important public health concern. Giardia 2 - 200,000 Giardiasis Mild to severe diarrhea, 10 - 100 nausea, indigestion a Details in Appendix I c Yates and Gerba 1998 b EPA 1999C

6-4 Chapter 6—Human Health Impacts of CSOs and SSOs

Organism Number per Gram of Feces Table 6.4

Fecal Coliform Bacteria 108 to 109 Concentration of Indicator Bacteria and Enteric Viruses 103 to 1012 Enteric Pathogens Shed Protozoan Parasites 106 to 107 by an Infected Individual (Schaub 1995)

This table shows that a single toxic substances present in CSO and therefore did not consider receiving infected person can shed a large SSO discharges that can cause human water impacts. number of pathogenic organisms. health impacts. Metals and synthetic organic chemicals are introduced into Metals are a human health concern sewer systems through a variety of for two reasons. First, metals are pathways (Ford 1994). These include persistent in the environment. This permitted industrial discharges, creates an increased chance of long- improper or illegal connections, term human exposure once metals are improper drain disposal of chemical introduced to a waterbody. Second, remnants, and urban runoff in areas metals such as arsenic, cadmium, served by CSSs. While the occurrence lead, and mercury bioaccumulate and concentration of specific toxics in the human brain, liver, fat, and in CSOs and SSOs vary considerably kidneys, causing detrimental effects. from community to community and Other impacts that can be caused by from event to event depending on site- metals include dermatitis, hair loss, specific conditions (see Tables 4.4 and gastrointestinal distress, bone disease, 4.5), EPA found no evidence of human and developmental illnesses. health impacts due to toxics in CSO and SSO discharges. Synthetic Organic Chemicals The synthetic organic chemicals that Metals have been identified in CSOs and The metals most commonly identified SSOs include chlorinated aromatic in wastewater include cadmium, hydrocarbons such as polychlorinated chromium, copper, lead, mercury, biphenyls (PCBs), chlorinated nickel, silver, and zinc (AMSA hydrocarbons such as pesticides, and 2003a). In CSSs, storm water can also polycyclic aromatic hydrocarbons. contribute metals. EPA’s Nationwide Synthetic organic chemicals can be Urban Runoff Program (NURP) ingested by drinking contaminated identified copper, lead, and zinc in water or by eating contaminated 91 percent of urban storm water fish that have bioaccumulated the samples collected (EPA 1983a). That chemical. Synthetic organic chemicals is, all three metals were present in can also be absorbed through the skin. 91 percent of samples. Other metals Their effects on humans range from commonly detected in urban runoff skin rash to more serious illnesses include arsenic, cadmium, chromium, including anemia, nervous system and nickel. The NURP Program and blood problems, liver and kidney focused on end-of-pipe samples and problems, reproductive difficulties, and increased risk of cancer.

6-5 Report to Congress on the Impacts and Control of CSOs and SSOs

6.1.3 Biologically Active Chemicals Little is known about the effectiveness Recent research efforts have begun to of conventional wastewater treatment consider the presence of biologically processes in the removal of these active chemicals—antibiotics, caffeine, biologically active chemicals. The hormones, human and veterinary relative concentrations of these drugs, and steroids—in wastewater chemicals in CSOs and SSOs are also (Kümmerer 2001). For the most part, unknown. these chemicals have not undergone extensive analysis for environmental fate and transport, human health 6.2 What Exposure Pathways impacts, or ecological impacts. and Reported Human Concerns about the presence of these Health Impacts are biologically active chemicals focus on Associated with CSOs and abnormal physiological processes and SSOs? reproductive impairments, increased of cancer, development umans may be exposed of -resistant bacteria, to the pollutants found in and potential increased toxicity of HCSOs and SSOs through chemical mixtures. Human health several pathways. The most common effects, however, are largely unknown pathways include recreating in waters (Kolpin et al. 2002). receiving CSO or SSO discharges, drinking water contaminated by CSO

Sources of Synthetic Organic Chemicals Deposition: The New York-New Jersey Harbor Estuary Program sponsored studies to estimate NY/NJ Harbor pollutant loads, including loads of synthetic organic chemicals to New York Harbor. As shown, the studies identified six sources of PCB inputs to the harbor. Application of a mass balance water quality food chain model for PCBs indicated that discharges of PCBs to the lower estuary from municipal point sources and CSOs are significant in causing PCB levels in striped bass to exceed the FDA standard for fish consumption (NYNJHEP 1996).

Atmospheric deposition 3% CSOs Landfill leachate <1% 10%

Urban storm water 15% Tributaries/ upstream inputs 50%

Municipal point sources 22%

6-6 Chapter 6—Human Health Impacts of CSOs and SSOs or SSO discharges, and consuming participating in water-based recreation or handling fish or shellfish that activities. Participation in more than have been contaminated by CSO one activity in a single water-based or SSO discharges. Other pathways recreation category is possible (e.g., include direct contact with discharges, respondents may report both sailing occupational exposure, and secondary and canoeing). Data from the most transmission. recent version of the survey (the period of July 1999 to January 2001) During wet weather events, CSO- and are presented in Table 6.5. SSO-impacted waterbodies typically receive microbial pathogens and A number of studies have documented toxics from a variety of other sources the risks of gastroenteritis among including municipal and industrial people recreating in water wastewater discharges, urban storm contaminated with microbial water runoff, and agricultural pathogens (NAS 1993; Wade et al. nonpoint source discharges. These 2003). Recreational exposure generally “interferences” can complicate the comes from contaminants suspended identification of specific cause-and- in the water column entering the body effect relationships between individual via oral ingestion. Exposure can also CSO or SSO discharges and human occur through the eyes, ears, nose, health impacts. anus, genitourinary tract, or dermal cuts and abrasions (Henrickson et 6.2.1 Recreational Water al. 2001). Contact with and ingestion of ocean water near wastewater or In the United States, millions of storm drain outfalls have resulted in people use natural waters (e.g., oceans, increases in reported respiratory, ear, lakes, rivers, and streams) each year and eye symptoms by ocean swimmers for a variety of recreational activities. and surfers (Corbett et al. 1993; Haile Table 6.5 The National Survey on Recreation et al. 1999). and the Environment, conducted by Participation in Water- the U.S. Forest Service and NOAA, Based Recreation in U.S. As described in Chapter 5, 25 percent between July 1999 and describes nationwide participation in of the beaches inventoried in EPA’s January 2001 50 categories of outdoor recreation National Health Protection Survey of activities (Leeworthy 2001). The Beaches under the BEACH Program The National Survey on Recreation survey estimates the percentage of the had at least one advisory or area and the Environment estimates population, 16 years of age or older, nationwide participation in various closing during the 2002 swimming outdoor recreation activities, including water-based recreation. Participation in more than one U.S. Population Boating/Floating a Fishing Swimming b activity is possible. (16 and Older) Percent participating 36% 34% 61% Number in millions 77 72 131 a Includes sailing, canoeing, kayaking, rowing, motor-boating, water skiing, personal watercraft use, wind surfing, and surfing. b Includes swimming in freshwater or saltwater, snorkeling, scuba, and visiting a beach.

6-7 Report to Congress on the Impacts and Control of CSOs and SSOs

season. Elevated bacteria levels were The source of the pathogens causing cited as the primary cause for 75 these waterborne disease outbreaks percent of these beach advisories or was not identified in CDC’s reports. closures. CSOs were reported to be These waterborne disease outbreaks, responsible for 1 percent of reported however, were caused by the types of closings and advisories, and 2 percent microbial pathogens found in CSOs of advisories and closures that had and SSOs. Figure 6.1 shows that a known cause. SSOs (including Shigella, which is present in CSOs sewer line breaks) were reported to and SSOs, caused the largest number be responsible for 6 percent of all of recreational water-associated reported advisories and closings, and outbreaks having a known cause. 12 percent of advisories and closing that had a known cause (EPA 2003a). Additional information from CDC Surveillance Summaries on outbreaks linked to recreational exposure in Reported Human Health Impacts fresh or marine waters contaminated A review of CDC Surveillance with microbial pathogens is presented Summaries identified 74 waterborne in Appendix I. disease outbreaks linked to open recreational waters (i.e., rivers, streams, CDC Surveillance Summaries also beaches, lakes, and ponds) from 1985 identify outbreaks linked to swimming to 2000. A waterborne pools or hot tubs. For swimming is defined by CDC as two or more pools and hot tubs, 191 recreational people experiencing similar illness after waterborne disease outbreaks with exposure to a waterborne pathogen. 14,836 cases of illness were reported Figure 6.1 A total of 5,601 cases of illness were to CDC between 1985 and 2000 (CDC attributed to these 74 waterborne Microbial Pathogens 1988, 1990, 1992, 1993, 1996a, 1998, Linked to Outbreaks disease outbreaks (CDC 1988, 1990, 2000, 2002). This is 265 times the in Recreational Waters, 1992, 1993, 1996a, 1998, 2000, 2002). 1985 - 2000

Shigella was the most commonly Other known agents identified cause of waterborne Norwalk-like 7% disease outbreaks linked to virus recreational waters between 1985 4% and 2000. Shigella has a relatively Giardia Unknown Agent 4% low infective dose of 10-100 and 23% is typically found in wastewater in concentrations of 0.1-1,000 per 100 Crypotosporidium mL of sewage. 4% Schistosoma spp. 7%

Shigella Pathogenic E.coli 21% 13%

Naegleria fowleri 17%

6-8 Chapter 6—Human Health Impacts of CSOs and SSOs number of illnesses reported for open ● Average concentration of fecal recreational waters. coliform bacteria at affected beaches;

Estimated Illnesses at Recognized ● Rate of infection for exposed Beaches population; and In developing this Report to ● Total annual number of Congress, EPA found an absence of gastrointestinal illnesses. direct cause-and-effect data relating the occurrence of CSO and SSO The number of highly credible discharges to specifi c human health gastrointestinal illnesses (HCGI) impacts. Lacking comprehensive resulting from human exposure data, EPA was able to implement an to SSOs and CSOs at recognized alternate approach to estimate the beaches was estimated by combining annual number of illnesses caused information on the number by recreational exposure to CSO and of exposed swimmer days, the SSO discharges at a small subset of the nation’s swimming areas—that is, concentration of indicator bacteria those recreational beaches recognized to which swimmers are exposed, and by state authorities (“recognized the Cabelli/Dufour dose-response beaches”). EPA’s illness estimate was functions for marine and fresh based on existing environmental waters. First, EPA calculated the total and recreational use databases. Data number of illnesses caused by CSOs limitations made it impossible to and SSOs, and then attributed them develop a comprehensive estimate separately to CSO illnesses or SSO of illness at all swimming areas at illnesses according to the ratio of CSO this time, but EPA believes that a to SSO events in the BEACH Survey. signifi cant number of additional A more detailed presentation of EPA’s illnesses occur in exposed swimmers methodology is included in Appendix at many inland and unrecognized J. beaches. Results from the analyses are presented EPA’s estimation of illness at in Table 6.6. The range shown reflects recognized beaches was limited to differences in how compliance rates gastrointestinal illness. EPA employed with beach advisories were estimated. a multi-step process, including the The lower bound uses a compliance following: rate of 90 percent, and the upper bound uses a compliance rate of 36 ● Number of recognized beaches percent. As shown, CSOs and SSOs using specific management are estimated to cause between 3,448 approaches; and 5,576 illnesses annually at the ● Number of CSO and SSO events recognized beaches included in this impacting recognized beaches; analysis. This estimate captures only a portion of the likely number of annual ● Number of individuals exposed illnesses attributable to CSO and SSO annually; contamination of recreational waters.

6-9 Report to Congress on the Impacts and Control of CSOs and SSOs

Table 6.6 Sourcee Lower Bound Upper Bound Estimated Illness SSOs 2,269 3,669 Resulting from CSOs 845 1,367 Recreational Exposure to CSOs and SSOs at Select CSO/SSOs 334 540 Beaches Total 3,448 5,576

This table shows the portion of the estimated number of annual illnesses attributable to exposure to CSO and 6.2.2 Drinking Water Supplies is accidentally ingested, drinking water SSO contaminated water at state- is an important pathway of exposure. recognized beaches in the U.S. and Public water systems regulated by EPA, its territories. states, and tribes provide drinking From 1985 to 2000, 251 outbreaks and water to 90 percent of Americans (EPA 462,169 cases of waterborne illness 2002e). Approximately 65 percent of related to contaminated drinking the population served by these systems water were reported to CDC (CDC receive water primarily taken from 1988, 1990, 1992, 1993, 1996a, 1998, surface water sources such as rivers, 2000, 2002). The vast majority of lakes, and reservoirs. The remaining 35 these cases of illness are from a percent drink water that originated as 1993 outbreak in groundwater (EPA 1999d). Milwaukee, Wisconsin, which affected an estimated 403,000 people; the CDC Reported Human Health Impacts did not specifically identify untreated wastewater as contributing to the People can contract waterborne Milwaukee outbreak. diseases through consumption of municipal drinking water, well As shown in Appendix I, EPA water, or contaminated ice. Because identified a subset of 55 of these 251 drinking water is directly ingested, outbreaks linked to drinking source and it is generally ingested in larger water contaminated with human quantities than recreational water that sewage or to drinking water taken

Between December 15, 1989, and January 20, 1990, residents of and visitors to SSOs linked to Drinking Cabool, Missouri, experienced 243 cases of diarrhea and four deaths (Swerdlow Water Contamination: et al. 1992). The CDC conducted a household survey and concluded that persons Cabool, MO drinking municipal water were 18.2 times more likely to develop diarrhea than persons using private well water (Geldreich et al. 1992). Observations suggested that Cabool’s SSS was prone to excessive storm water infiltration and therefore was unable to convey all of the wastewater to the treatment facility. As a result, frequent capacity-related SSOs occurred, spilling sewage onto the ground surface in areas over drinking water distribution lines and near water meter boxes. During the outbreak, the water distribution system was under construction, allowing untreated sewage to contaminate the drinking water system (Geldreich et al. 1992).

6-10 Chapter 6—Human Health Impacts of CSOs and SSOs

Other known Figure 6.2 Shigella agents 2% 7% Microbial Pathogens 2% Causing Outbreaks Pathogenic E. coli Linked to Drinking Water 6% 1985 - 2000

Giardia was responsible for 42 Giardia Cryptosporidium 42% percent of the outbreaks of 10% waterborne disease linked to drinking water.

Unknown agent 31% from rivers, streams, or lakes. Of Proximity of CSO Outfalls to Drinking these, EPA identified 11 outbreaks Water Intakes accounting for 7,764 cases of As described in Chapter 5 and waterborne illness that CDC linked documented in Appendix F, EPA geo- to drinking water contamination with referenced more than 90 percent of sewage. Only one of these outbreaks all CSO outfalls. EPA compared the was linked directly to CSOs or SSOs. locations of these CSO outfalls to The outbreaks were caused, however, drinking water intakes. Only drinking by the types of microbial pathogens water systems that serve a community found in CSOs and SSOs. As shown in on a year-round basis and that use Figure 6.2, Giardia, which is present surface water as the primary source in significant concentrations in CSOs of water were considered in this and SSOs, caused the largest number analysis. Approximately 7,519 such of outbreaks linked to drinking water. systems operate in the United States, A summary of these outbreaks is of which 6,631 (85 percent) have been provided in Appendix I.

In July 1998, a lighting strike and the subsequent power outage caused 167,000 gallons of raw sewage to flow into Brushy Creek in Texas (TDH 1998). The sewage Drinking Water contaminated municipal drinking water wells that supplied the community of Contaminated by Sewage: Brushy Creek. Although the wells are not in direct contact with surface waters (the Brushy Creek, TX wells are more than 100 feet deep and encased in cement), drought conditions at the time are thought to have caused water from Brushy Creek to be drawn down into the aquifer and into the wells through a geologic fissure. It is estimated that 60 percent of Brushy Creek’s population of 10,000 were exposed to Cryptosporidium and approximately 1,300 residents became ill with cryptosporidiosis. Residents of Brushy Creek were supplied water from the contaminated wells for approximately eight days (TDH 1998).

6-11 Report to Congress on the Impacts and Control of CSOs and SSOs

geo-referenced to the NHD and are authorities found, where a primary included in this analysis. drinking water intake was located within one mile of an active CSO, each All of the drinking water systems drinking water authority was aware within one mile of any CSO of the CSO. Further, in all cases, lines outfall were selected for further of communication existed between analysis. As shown in Table 6.7, EPA the drinking water authority and the identified seven states with outfalls NPDES permit-holder. In many cases located within one mile upstream the drinking water authority indicated of a drinking water intake. Phone adjustments are made to the treatment interviews were conducted with process during wet weather. both the NPDES permit-holder and drinking water authority in This assessment indicates that CSO’s the identified areas to confirm the generally do not pose a major risk location of the CSO outfall, the status of contamination to most public of the CSOs (active/inactive), and the drinking water intakes. However, to location of the drinking water intake. understand the relationship between In many cases, the NPDES permit- a discharge point and a downstream holder reported that the CSO was drinking water intake the transport inactive, as a result of sewer separation and fate of the discharge between the or other CSO controls. two points must be modeled under the range of real world flow conditions for EPA identified and confirmed 59 that stream reach. Such modeling is active CSO outfalls within one mile of beyond the scope of this report. a drinking water intake. One NPDES- permit holder reported that receiving 6.2.3 Fish and Shellfish water modeling found that the Table 6.7 drinking water intake (located within Fish and shellfish are widely Association of CSO one mile, but on the opposite side consumed in the United States and Outfalls with Drinking of the river) was not affected by the are a valued economic and natural Water Intakes CSO. Interviews with drinking water resource (NYNJDEP 2002a). In 1995, EPA identified 59 CSO outfalls in seven states with outfalls located within one mile upstream of a EPA Region State Number of CSO Outfalls within 1 mile drinking water intake. upstream of a drinking water intake 1ME7 2NY7 3PA19 3WV9 4KY7 5 IN 3 5OH7 Total: 59

Note: EPA was unable to confirm data for an additional 14 outfalls in two states ( PA and WV); these outfalls are not included in this table.

6-12 Chapter 6—Human Health Impacts of CSOs and SSOs the most recent year for which data illness associated with eating sewage- are available, 77 million pounds of contaminated raw shellfish and fish is clams, oysters, and mussels were gastroenteritis (CERI 1999). harvested in the coastal United States (NOAA 1997). Shellfish grown in A review of CDC Surveillance contaminated waters concentrate Summaries identified eight microbial pathogens and can have waterborne disease outbreaks linked to higher concentrations than the the consumption of contaminated fish waters in which they are found. or shellfish for the period 1985-2000. Viable pathogens can be passed on These outbreaks resulted in 995 cases to humans by eating whole, partially of illness (CDC 1990, 1995, 1996b, cooked, or raw contaminated shellfish. 1997). More information on these outbreaks is provided in Appendix I. In most cases, the contaminated Reported Human Health Impacts fish or shellfish were exposed to or The World Health Organization grown in sewage-contaminated water. reported that seafood is involved in 11 Waste dumped overboard by boaters percent of all disease outbreaks from and improperly treated sewage were food ingestion in the United States the most commonly cited sources (WHO 2001). The most common of fish and shellfish contamination.

The New York State Department of Health compiled data on shellfish-associated illness (most commonly gastroenteritis) recorded in New York State from 1980 to 1999 (NYNJHEP 2002b). The incidence of reported illness has dropped markedly Shellfish-Associated Illness: since its peak in 1982. The study was able to trace most of the outbreaks in 1982 to New York State Rhode Island shellfish. The study noted that it is often difficult to identify the source of the shellfish that induced the outbreak. Decreases in shellfish-associated disease are attributed to a number of factors including: improvements in wastewater treatment leading to reductions in concentrations of waterborne microbial pathogens; more restrictions on shellfish harvesting in contaminated areas; and more public awareness of the risks associated with consuming raw shellfish. The study also noted that although shellfish beds are carefully monitored for pathogenic contamination, the levels of toxic contaminants in shellfish, including impacts from marine algal toxins, need additional study.

Number of Reported Outbreaks of Shellfish Associated Illnesses, New York State 140 120 100 80 60 40 # Outbreaks 20

0

98

1982 1980 1984

1986 1990 1988

19 1996 1992 1994 Year

6-13 Report to Congress on the Impacts and Control of CSOs and SSOs

Direct links to CSO and SSO events This event resulted in 39 cases of as a cause of contamination were not hepatitis A (Vonstille 1993). made. 6.2.5 Occupational Exposures 6.2.4 Direct Contact with Land- Many occupational settings Based Discharges occasionally expose personnel to Many SSOs discharge to terrestrial microbial pathogens. These include environments including streets, restaurants and food processing, parks, and lawns. CSSs and SSSs agriculture, hospitals and healthcare, can also back up into buildings, emergency response, and wastewater including residences and commercial treatment. establishments. These land-based discharges present exposure pathways Wastewater treatment plant workers that are different than those pathways and public works department associated with typical discharges to personnel operate and maintain water bodies. Exposure to land-based wastewater treatment facilities and SSOs and building backups typically respond to CSO or SSO events. In occurs through dermal contact. The doing so, they may be exposed to resulting diseases are often similar microbial pathogens present in CSOs to those associated with exposure and SSOs. Police, firefighters, rescue through drinking or swimming in divers, and other emergency response contaminated water, but may also personnel also face exposure to include illness caused by inhaling CSOs and SSOs. Depending on the microbial pathogens (CERI 1999). context in which the overflow event occurs, exposure can occur through Reported Human Health Impacts inhalation, ingestion, and dermal contact. Adherence to good personal In general, very few outbreaks hygiene and the appropriate use of associated with direct contact personal protective equipment are with land-based SSOs have been important in minimizing the potential documented. Land-based SSOs for injury or illness. tend to leave visible evidence of their occurrence, such as deposits of sanitary products and other wastes Reported Human Health Impacts commonly flushed down a toilet. The Comprehensive epidemiologic presence of these items often acts as research on waterborne illness a deterrent to direct contact with the associated with occupational exposure SSO. Further, municipal response to untreated wastewater is lacking. to land-based SSOs often includes Some researchers believe that cleaning the impacted area by washing wastewater workers may experience the sewage into a nearby manhole increased numbers of bacterial, viral, or storm drain and disinfecting as and parasitic infections without needed. This review identified one exhibiting signs or symptoms of confirmed outbreak resulting from illness. These are called “sub-clinical” direct contact with a discharge of infections (AFSCME 2003). One untreated sewage in Ocoee, Florida. study concluded that the lowest rates

6-14 Chapter 6—Human Health Impacts of CSOs and SSOs of illness are found among workers 6.2.6 Secondary Transmission employed in wastewater treatment An individual who contracts for less than five years, the highest an infection from exposure to a rates in workers with five to 10 years waterborne microbial pathogen may, of exposure, and lower rates again in turn, infect other individuals, in workers with 15 years or more regardless of whether symptoms are of exposure (Dowes et al. 2001). An apparent in the first individual. This explanation for this is that workers is commonly referred to as “secondary build immunity to many of the transmission.” The rate of secondary microbial pathogens present in the transmission depends largely on work environment over the course the particular microbial pathogen. of their employment, and those who Illnesses caused by secondary become very ill no longer work in the transmission are not included in CDC plant. This phenomenon is also known Surveillance Summaries, which list as the “healthy worker effect.” only primary illnesses. In general, the effect of microbial pathogens, other than hepatitis A, on Reported Human Health Impacts wastewater workers has been given Secondary transmission statistics little attention, and “there have been obtained from a variety of waterborne few epidemiologic studies conducted and non-waterborne disease outbreaks among sewage workers in the U.S. to are shown in Table 6.8 (NAS 1998). As determine the actual and presented, the secondary attack ratio types of infections” (AWR 2001). represents the ratio of secondary cases to primary cases. One confirmed waterborne disease outbreak through occupational exposure was identified from 6.3 Which Demographic the review of CDC Surveillance Groups Face the Greatest Summaries. In 1982, 21 cases Risk of Exposure to CSOs of gastrointestinal illness were and SSOs? identified among 55 police and fire department scuba divers training everal demographic groups in sewage-contaminated waters face increased risk of exposure (CDC 1983). The divers developed Sto the pollutants in CSOs and gastrointestinal disease more than SSOs because they are more likely to four times as frequently as nondiving spend time in locations impacted by firefighters, the control group in the such discharges. These groups include study. Although the causes of illness people recreating in CSO- and SSO- in many divers were not identified, impacted waters, subsistence fishers, gastrointestinal parasites were found shellfishers, and wastewater workers. in 12 divers: Entamoeba histolytica The sections that follow describe in five divers, and Giardia lamblia in exposure risks for each of these groups seven divers. in greater detail. This information is

6-15 Report to Congress on the Impacts and Control of CSOs and SSOs

Table 6.8 Microbial Pathogen Secondary Attack Ratio Source of Outbreak Examples of Secondary Transmission from Cryptosporidium 0.33 Contaminated apple cider Waterborne and Non- Shigella 0.28 Child day care center Waterborne Disease Rotavirus 0.42 Child day care center Outbreaks (NAS 1998) Giardia 1.33 Child day care center An individual who contracts an Unspecified virus causing 0.22 Contaminated drinking water infection may, in turn, infect other viral gastroenteritis individuals. This table shows for Norwalk virus 0.5 - 1.0 Contaminated recreational water every two individuals infected with Norwalk virus, one to two individuals can become infected via secondary presented based on the availability of 6.3.2 Subsistence and Recreational transmission. literature documenting each group’s Fishers potential for exposure, rather than Subsistence and recreational fishers on the relative sensitivity of each and their families tend to consume population to the pollutants in CSO more fish and shellfish than the and SSO discharges. general population, and men tend to consume more fish and shellfish than 6.3.1 Swimmers, Bathers, and women (Burger et al. 1999). Further, Waders in areas conducive to fishing, people Swimming in marine and fresh water with lower education levels or lower has been linked directly to diseases income levels consume more fish and caused by the microbial pathogens shellfish, as it is often an inexpensive found in wastewater (Cabelli et source of protein (Burger et al. 1999). al. 1982). For example, a 1998 Cultural preferences influence the study comparing bathers and non- amount and frequency of fish as well bathers found that 34.5 percent of as shellfish consumption and the gastroenteritis and 65.8 percent of ear methods for preparing and serving infections reported by participants fish and shellfish. For example, a study were linked to bathing in marine of two Native American groups in waters contaminated with sewage. Puget Sound in Washington found The percentage of people who lost at that these groups consumed fish at least one day of normal activity due to much higher rates than the general contacting one of the illnesses studied public and at rates greater than those ranged from 7 to 26 percent (Fleisher recommended by EPA (Toy et al. et al. 1998). 1996). Asians and Pacific Islanders Many variables influence the exposure generally consume fish at much higher of people to pathogens in recreational rates than the general United States water. These factors include whether population (Sechena et al. 1999). people swim or wade, the type of In addition, cooking methods and pathogens present at the time of consumption rates of parts of the exposure, the route of exposure fish that tend to concentrate toxins (ingestion or skin contact), and (e.g., skin, head, organs, and fatty individual susceptibility to waterborne tissue) can increase the risk of human disease (WSDH 2002). health impacts from consuming

6-16 Chapter 6—Human Health Impacts of CSOs and SSOs contaminated fish and shellfish (e.g., resulting from exposure to the types Wilson et al. 1998; WDNR 2003). of pollutants present in CSOs and SSOs. Specific characteristics of Fish and shellfish advisories target these demographic groups that make recreational and subsistence fishers. them particularly susceptible to these Despite warnings and advisories, illnesses are discussed in more detail in however, many fishers consume the following sections. These sensitive their catch. May and Burger (1996) groups represent almost 20 percent found that a majority of urban and of the U.S. population (Gerba et al. suburban recreational fishers ignored 1996). Also, tourists and travelers may warnings issued by the New York State be more prone to waterborne illnesses Department of Health and the New than local residents (EPA 1983b). EPA Jersey Department of Environmental research has found that when exposed Protection. to pathogens found in local sewage, local residents have been shown to 6.3.3 Wastewater Workers develop fewer symptoms than non- Wastewater workers are more likely residents or visitors. to come into contact with untreated wastewater than the general public, 6.4.1 Pregnant Women but there is insufficient data to During , women appear determine whether wastewater to be at greater risk of more serious workers or their families face an disease outcomes from exposure to increased risk of illness as a result the types of enteric viruses found of this exposure. Although there is in CSOs and SSOs (Reynolds 2000). disagreement regarding the benefits of Waterborne diseases contracted during additional immunization above those pregnancy may result in transfer of recommended by CDC for the adult the illness to the child either in utero, general population (i.e., diptheria during birth, or shortly after birth and tetanus), WERF (2003b) asserts (Gerba et al. 1996). that wastewater workers should be vaccinated for both Hepatitis A and B. 6.4.2 Children The incidence of several waterborne 6.4 Which Populations Face infectious diseases caused by the the Greatest Risk of Illness types of pollutants present in CSO and SSO discharges is significantly from Exposure to the greater in infants and children than Pollutants Present in CSOs in the general population (Laurenson and SSOs? et al. 2000). Factors contributing to ertain demographic groups, the susceptibility of children include including pregnant women, children’s naturally immature immune Cchildren, individuals with systems and child-associated behaviors compromised immune systems, that result in abnormally high and the elderly, may be at greater ingestion rates during recreational risk than the general population for exposure to contaminated water serious illness or a fatal outcome (Laurenson et al. 2000). For example,

6-17 Report to Congress on the Impacts and Control of CSOs and SSOs

children frequently splash or swim in 5, respectively experience the highest waters that would be considered too mortality from diarrhea as a result of shallow for full-body immersion by infection by waterborne or foodborne adults (EPA 2001b). illness (Gerba et al. 1996). Studies of a giardiasis outbreak in Sweden 6.4.3 Immunocompromised Groups that occurred when untreated sewage contaminated a drinking water supply People with compromised immune found people over 77 years old faced systems, such as those with AIDS, an especially high risk of illness organ transplant recipients, and (Ljungstrom and Castor 1992). people undergoing chemotherapy, are more sensitive than the general public to infection and illness caused 6.5 How are Human Health by the types of pollutants present in CSO and SSO discharges (Gerba Impacts from CSOs and et al. 1996). Using Wisconsin death SSOs Communicated, certificate data, Hoxie et al. (1997) Mitigated, or Prevented? analyzed cryptosporidiosis-associated variety of programs are in mortality in AIDS patients following place to reduce human health the 1993 Milwaukee outbreak that Aimpacts associated with affected an estimated 403,000 people. exposure to microbial pathogens The researchers found that AIDS and toxics. These programs generally was the underlying cause of death involve preventive measures enacted for 85 percent of post-outbreak by public health officials, including: cryptosporidiosis-associated deaths communication efforts to warn the among residents of the Milwaukee public about risk and threats; and area. Further, the researchers found monitoring, reporting, and tracking that AIDS mortality increased activities. This section is focused on significantly in the six months agencies, activities, and programs immediately after the outbreak, designed to communicate, mitigate, then decreased to levels lower than or prevent potential human health expected, and then returned to impacts from exposure to CSOs and expected levels. This suggests that SSOs. some level of premature mortality was associated with the outbreak. 6.5.1 Agencies and Organizations Responsible for Protecting 6.4.4 Elderly Public Health The elderly are at increased risk for Numerous agencies and organizations waterborne illness due to a weakening have responsibilities for monitoring, of the immune system that occurs tracking, and notifying the public of with age (Reynolds 2000). Studies potential human health impacts. These have found that people over 74 years include federal and state agencies, old, followed by those between 55 local public health officials, owners and 74, and then by children under and operators of municipal wastewater

6-18 Chapter 6—Human Health Impacts of CSOs and SSOs collection and treatment facilities, and infectious diseases. Waterborne non-governmental organizations. disease prevention is a priority for this program. Working with EPA, CDC Federal Agencies coordinates national reporting of EPA administers a national water waterborne illness outbreaks through quality standards program that its Outbreak Surveillance System. establishes criteria to support This system compiles state-reported designated uses including recreation, outbreaks to characterize waterborne drinking water supply, and shellfish outbreaks epidemiologically (e.g., to harvesting. EPA also administers a investigate the agents, reasons for the national safe drinking water program outbreak, and adequacy of various with a goal that, by 2005, 60 percent of treatment methods) and to strengthen the population served by community the public health community’s ability drinking water systems will receive to respond. Outbreak summaries their water from systems with active are produced biennially. With source water protection programs the cooperation of state health (EPA 1997b). In developing source departments and other national water protection programs, EPA partners, CDC’s Division of Parasitic specifically encourages suppliers Diseases and Division of Bacterial and to consider CSOs, sewer system Mycotic Diseases are responsible for failures, and wet weather municipal the investigation, surveillance, and effluent point source discharges as control of specific groups of diseases, sources of microbial contamination. including many pathogens linked to Further, drinking water intakes and waterborne illness. their designated protection areas are NOAA works to protect and identified as “sensitive areas” under the preserve U.S. living marine resources CSO Control Policy. The elimination, through scientific research, fisheries control, or relocation of CSO outfalls management, enforcement, and that discharge to sensitive areas habitat conservation. As detailed in are to be given high priority in the Section 5.3.2 of this report, NOAA development and implementation of is currently working with Interstate CSO LTCPs (EPA 1994a). Shellfish Sanitation Conference As discussed earlier in Section 5.5.2 (ISSC), EPA, and FDA to develop an of this report, EPA’s BEACH program information resource on shellfish conducts an annual survey of the safety. This data system will house nation’s swimming beaches. The shellfish growing area monitoring, program was created to reduce health survey, and classification data. risks to swimmers due to contact FDA administers the National Shellfish with contaminated water by working Sanitation Program, an effort intended to improve monitoring and public to standardize the inspection and notification procedures at beaches. monitoring of shellfish growing CDC’s National Center for Infectious areas and shellfish packing/shucking Diseases works to prevent illness, facilities. Working with EPA, FDA disability, and death caused by

6-19 Report to Congress on the Impacts and Control of CSOs and SSOs

publishes guidance on the safety coordination with other state and attributes of fish and fishery products, federal agencies and programs. This including acceptable levels of organic coordination includes providing and inorganic compounds such as data on waterborne illness and mercury and PCBs. investigations to CDC.

USGS plays an active role in State environmental agencies conduct monitoring and reporting the water quality monitoring and quantity and quality of the nation’s assessment programs and require water resources. USGS helps to assess monitoring to be conducted by others, water quality problems and sources such as local sanitation districts, of pollution, including CSOs and public water systems, regional SSOs, by studying how pathogens and planning agencies, and recreational other agents of waterborne disease facilities. State environmental or interact with the environment and by natural resource agencies also monitoring and reporting the quality monitor fish and shellfish. These of the nation’s water resources. monitoring programs provide data for management decisions at the state State Agencies level in response to environmental and public health concerns. In addition State public health agencies track to monitoring, state agencies perform communicable diseases, perform sanitary surveys to identify problems outbreak investigations, and issue that could affect the safety of the warnings to the public. These agencies drinking water supply. A sanitary integrate and compile findings survey is a physical inspection of the from local efforts, and they provide

The State of Connecticut has a comprehensive monitoring program for its coastal Coastal Beach waters, with standards and guidelines set by the state. The state collects and Monitoring Program: analyzes samples taken at four coastal state parks on Long Island Sound. At least Connecticut 18 municipalities in the state’s four coastal counties monitor their own beaches, following the ocean and bay beachwater-quality monitoring protocol established by the Connecticut Departments of Public Health and Environmental Protection. In 2002, Connecticut set aside a $226,000 grant to integrate monitoring at municipal beaches into a state-administered sampling and public notification plan for the entire state. The beach grant funded a courier service to bring municipal beach samples to the Department of Public Health lab, where the state analyzes the samples free of charge.

The Rhode Island Health Department requires every licensed beach to sample its Beach Monitoring and water and test for the presence of fecal coliform bacteria. The Rhode Island water Public Notification Program: quality standard for recreation is 50 MPN per 100 ml of salt water and 200 MPN Rhode Island per 100 ml of fresh water. Results are posted on the department’s website, along with advisories on waterborne illness and beach closures and openings. Public notification of beach closures is accomplished in several ways, including the use of color-coded flags at beaches, press releases, and notices on the department website. The website also supports on-line reporting by the public of suspected beach-related illnesses.

6-20 Chapter 6—Human Health Impacts of CSOs and SSOs water treatment and distribution health divisions generally have system and a review of operation and responsibility for monitoring, analysis, maintenance practices. and posting of recreational waters, where needed. Owners and operators States also implement notification of municipal wastewater collection programs to warn citizens about and treatment facilities have their human health impacts associated with own responsibilities, many of which recreation at contaminated beaches are stipulated as NPDES permit and consumption of contaminated requirements, including notifying water, fish, or shellfish. the public when SSOs occur and reporting SSOs to state regulatory and Local Agencies public health agencies. Communities Local public health agencies, regional with CSSs are required to implement planning authorities, and the owners public notification programs as part of and operators of wastewater collection implementing the NMCs. and treatment facilities have distinct responsibilities to protect public 6.5.2 Activities to Protect Public health. Working with state oversight, Health from Impacts of CSOs city and county health departments and SSOs often maintain separate divisions The principal activities undertaken to for tracking communicable diseases protect the public from the impacts and for environmental health. The of CSOs and SSOs can be grouped communicable disease divisions into three areas: exposure pathway of these departments generally monitoring, public notification, and have responsibility for cataloging, research. These activities protect investigating, and reporting cases of public health by identifying possible “reportable illness” to the appropriate sources of pathogens, reducing public state agency. The environmental exposure through notification and

In California, the Orange County Health Care Agency’s Ocean Water Protection Program has a mission to ensure that all public recreational waters meet Local Public Health Activity: bacteriological water quality standards for full body contact recreation activities, Orange County, CA such as swimming, surfing, and diving. Staff collect water samples at approximately 150 locations along the shoreline of Orange County for laboratory analysis for indicator bacteria. Results of the analysis are reviewed by program specialists who determine if action needs to be taken to protect the public. Staff are available to respond on a 24-hour basis to investigate reports of contamination incidents, including SSOs, affecting Orange County’s public beaches.

The Allegheny County Health Department in Pennsylvania implemented a public notification program designed to warn recreational users of health risks in Local Public Health Activity: CSO-impacted waters in the Pittsburgh area. The program includes publishing Allegheny County, PA advisories in local newspapers and producing public service announcements on local television stations to educate the public about health risks associated with CSO discharges. The department also installed orange warning flags that read “CSO” at 30 locations near CSO outfalls. The flags are raised to warn recreational users whenever CSO discharges cause or contribute to elevated bacteria levels.

6-21 Report to Congress on the Impacts and Control of CSOs and SSOs

use restriction, when necessary, and ● including continuing research by public health indicator organisms, enteric experts to better protect public health viruses, and parasitic protozoa; in the future. More detail on each ● Disinfectants including chlorine, activity is presented below. chlorine dioxide, and chloramine;

Exposure Pathway Monitoring ● Disinfection byproducts including Exposure pathway monitoring bromate, chlorite, haloacetic acids, programs focus on recreational waters, and trihalomethanes; public drinking water systems, and ● Inorganic chemicals including fish and shellfish in order to reduce metals, nitrate, and nitrite; the risk of human health impacts from exposure to contaminated water and ● Organic chemicals including a food. broad list of agricultural and industrial products; and Recreational waters are typically ● Radionuclides. monitored using indicator bacteria to detect the presence of or the potential If monitoring shows the drinking for microbial pathogen contamination. water is contaminated, the owner or If the bacteria levels in a given water operator of the public water system sample exceed the state standard for is required to shut down the system recreational waters, advisories are and/or direct the public to take posted or the waterbody is closed. For precautions, such as boiling water. example, EPA’s 2002 BEACH Program found that 91 percent of surveyed Fish and shellfish monitoring is beaches had some type of water administered jointly by state agencies, quality monitoring program. Though EPA, NOAA, and FDA. Bacteriological the frequency of monitoring varied, 63 monitoring is used to assess the percent of the beaches were monitored potential presence of microbial at least once per week (EPA 2003a). pathogens in shellfish harvesting areas. States, U.S. territories, and authorized Public water systems are governed tribes have primary responsibility for by National Primary Drinking Water protecting residents from the health Standards, also known as primary risks of consuming contaminated, standards (EPA 2003f). Primary noncommercially caught fish. This standards are legally enforceable is accomplished by issuing of fish standards that protect public health consumption advisories. These by limiting the levels of specific advisories inform the public when contaminants in drinking water. high concentrations of contaminants To protect the health of those have been found in local fish. They being served, public water systems also include recommendations to have monitoring requirements. limit or avoid eating certain fish Contaminants monitored are as species from specific waterbodies or follows (EPA 2002f): waterbody types.

6-22 Chapter 6—Human Health Impacts of CSOs and SSOs

Public Notification EPA’s National Epidemiological Public notification programs provide and Environmental Assessment of information to communities regarding Recreational (NEEAR) Water Study the occurrence of CSO and SSO is intended to develop a better events and ongoing efforts to control understanding of water pollution at discharges. beaches, recreational use of beaches, and public health. As part of the Public notification programs include BEACH Program, this effort seeks to posting temporary or permanent improve beach monitoring by linking signs where CSOs and SSOs real-time monitoring results with occur, coordinating with civic and meaningful risk-based guidelines. environmental organizations, and distributing fact sheets to the public EPA’s Office of Research and and the media. Notices in newspapers Development has completed the are used to publicize CSO or SSO first in a planned series of studies discharges in some states. Radio and to estimate the urban contribution television announcements may be to the total Cryptosporidium and appropriate for CSOs and SSOs with Giardia loads to receiving waters (EPA unusually severe impacts. Distribution 2003f). It is hoped that the studies will of information on websites is rapidly provide a basis for designing source gaining wider use. Additional water protection programs. information on reporting and public notification is presented in Chapter 8 of this Report to Congress and in the 6.6 What Factors Contribute technology descriptions included as to Information Gaps in Appendix L. Identifying and Tracking Human Health Impacts Research from CSOs and SSOs? Several research activities are expected ystematic data on human to improve the ability of public health health impacts as a result of programs to protect humans from Sexposure to CSOs and SSOs impacts associated with CSOs, SSOs, are not readily available. The chief and other sources of pollution. Two factors that account for the absence examples are provided below. of direct cause-and-effect data

Monitoring Identifies SSS In 1984, public drinking water for the community surrounding Braun Station, Texas, as Source of Drinking Water was drawn from an artesian well that was not filtered but was chlorinated prior Contamination: to distribution. At the time, well water was not routinely sampled in this region Braun Station, TX of Texas. Community complaints, however, convinced authorities to begin testing. Fecal coliform level as high as 2,600/100 mL were measured in untreated well water samples. Subsequent dye tests indicated that the community’s SSS was leaking into the well water. When attempts to identify the exact site of contamination were not successful, an alternative water source was provided to the community (D’Antonio et al. 1985).

6-23 Report to Congress on the Impacts and Control of CSOs and SSOs

are underreporting of waterborne tracking systems employed by the disease and the reliance of water CDC; and quality monitoring activities on ● The integration of state and indicator bacteria instead of microbial local reporting and investigation pathogens. Both factors are discussed protocols for waterborne disease below. outbreaks. Large outbreaks are more likely 6.6.1 Underreporting to be noticed and reported than Reporting and tracking of outbreaks smaller outbreaks. Nevertheless, the of waterborne disease are difficult source and exposure pathway of the under the best circumstances. 1993 Milwaukee cryptosporidiosis Underreporting stems from a number outbreak, the largest documented in of causes. CDC’s waterborne disease U.S. history, remained unidentified for outbreak surveillance system depends more than two weeks (CDC 1996a). on states to report outbreaks, and This outbreak, affecting an estimated this reporting is often incomplete. 403,000 people, was detected only Existing local systems for tracking “when increased sales of antidiarrheal these outbreaks often lack sufficient medicines were observed and reported information on the cause of the to the local public health agency” outbreak to establish whether CSOs (Frost et al. 1995). and SSOs are suspected source. 6.6.2 Use of Indicator Bacteria Factors that affect the likelihood that outbreaks will or will not be detected, Indicator bacteria are used to investigated, and reported include evaluate human health risks from (adapted from CDC 2000): contaminated water without sampling for every possible microbial pathogen. ● Public awareness about illness As described in Section 6.1.1, symptoms, environmental indicator bacteria are relatively easy conditions that might precipitate to detect and are used to indicate an outbreak, and where to report the likely presence of fecal-borne symptoms; microbial pathogens. There is ongoing scientific debate regarding the use of ● The frequency with which people indicators and their ability to predict experiencing illnesses related to human health impacts. Some specific exposure to contaminated water criticisms of the use of indicator seek medical care from the same bacteria are as follows: provider;

● The adequacy of laboratory ● A single indicator organism infrastructure to fully investigate may be insufficient to establish outbreaks; water quality standards. EPA’s current water quality criteria ● The compatability of local are targeted toward protecting reporting requirements for specific people participating in waterborne diseases with data

6-24 Chapter 6—Human Health Impacts of CSOs and SSOs

recreational activities from acute ● Indicator bacteria area simple and gastrointestinal illness (EPA inexpensive to measure (Griffin et 2002g). al. 2001).

● Current bacterial detection ● Studies show that E. coli and methods are subject to false enterococci exhibit a strong positives and false negatives relationship to swimming- (Griffin et al. 2001). associated gastrointestinal illness (Fattal et al. 1987; Cheung et al. ● Coliform bacteria can survive and 1990; EPA 2002g). replicate in waters and soils under certain environmental conditions. ● Indicator bacteria are present Their presence is not always due where fecal contamination occurs; to recent fecal contamination. they are always present in feces In addition, all current bacteria and at higher levels than most indicators are shed by animals. enteric pathogens (Griffin et al. Their occurrence in the 2001). environment does not always EPA continues to encourage states indicate that human pathogens are and authorized tribes to use E. coli present or that contamination was or enterococcci as the basis of their due to a human source (Griffin et water quality criteria for protecting al. 2001). recreational waters. ● Indicator bacteria do not directly indicate the presence of viruses, which survive longer in marine 6.7 What New Assessment and waters and have a low infective Investigative Activities are dose (Seyfried et al.1984; Freeman Underway? 2001; Schvoerer et al. 2001). everal local government agencies Bacteriophages have shown merit are implementing innovative for use as an alternative to indicator programs to identify risks and bacteria to identify human health S to track the types of illness associated risks. Specifically, Bacteroides fragilis with the pathogens present in CSO bacteriophages have been found to be and SSO discharges. Select examples more resistant to chlorine than current are provided in this section. indicator bacteria and are thought to be good indicators of enteric viruses. 6.7.1 Investigative Activities Bacteriodes also show potential for use as an indicator of recent fecal Monitoring, modeling, and other contamination (Griffin et al. 2001). investigative activities are useful tools in reducing human exposure Although EPA recognizes the to pathogens, identifying waterborne limitations of indicator bacteria, they and foodborne disease outbreaks, continue to be used to assess potential and assessing illness patterns. Some human health risk because: innovative investigative programs

6-25 Report to Congress on the Impacts and Control of CSOs and SSOs

intended to reduce human health ● San Diego County, California impacts and risk are described below. Department of Environmental Health and a group called Surfers ● In Texas, the Austin-Travis Health Tired of Pollution conducted a and Human Services Department self-reported ocean illness survey. has a predictive model for Between August 1, 1997, and recreational water quality at the December 31, 1999, 232 illnesses Barton Springs pool. If the Barton were reported. The county plans a Creek watershed receives more second survey (Clifton 2002). than one inch of rainfall, the pool is closed until monitoring ● The Douglas County, Nebraska determines it is safe to reopen Health Department compares (Staudt 2002). reported illnesses with a computer model that provides epidemiologic ● New York City has an advanced analysis for 1- to 10-year periods. rainstorm modeling system that Reported illnesses are compared predicts the estimated amount of with projected baselines and trends fecal matter that will contaminate to determine if an outbreak is beaches after a measurable rainfall. occurring (Kurtz 2002). This information is used to make decisions on beach closures and is ● New York City has an active shared with all area beaches and outbreak monitoring procedure. neighboring states (Luke 2002). The Department of Health tracks reports of giardiasis and ● Orange County, California, cryptosporidiosis by visiting labs maintains a passive reporting in New York City on a weekly system for illnesses from basis and making sure all samples recreational waters. Between 1998 testing positive for the pathogens and 2002, Orange County received are reported. The Department of 110 ocean and bay bather illness Health receives weekly tallies of reports and one illness report diarrheal medicine sold in the area from a freshwater lake (Mazur and has a clinical lab monitoring 2002). system to track the number of ● Boston, Massachusetts, operates stool samples tested. Finally, the a waterborne surveillance project city monitors hospital emergency that monitors Cryptosporidium rooms for the number of people and Giardia illnesses from complaining of diarrhea and drinking water. The program uses vomiting (Seeley 2002). fixed populations within the city (schools, nursing homes, prisons) as control groups (Gurba 2002).

6-26