2
Status of Small Water Systems

More than 50 million U.S. residents (nearly 20 percent of the population) obtain their water from water utilities serving fewer than 10,000 people (EPA, 1994). The communities that rely on these smaller water systems are responsible for providing the financial means to build the systems, operate and maintain them, and ensure that they meet federal drinking water standards. This chapter discusses the financial status of small communities, their track record in meeting requirements of the Safe Drinking Water Act (SDWA), and their ability to pay for needed improvements to water treatment systems and infrastructures. It also reviews existing data on outbreaks of waterborne disease in small and large communities. As discussed in this chapter, small communities are often ill-equipped to assume the financial and managerial responsibilities associated with providing high-quality water service.

Financial Resource Limitations in Small Communities

While every town and city is unique and not all face the same problems, many small communities have economic characteristics that make it difficult for them to raise the funds needed for adequate drinking water service. Small communities can generally be divided into two groups: those in nonmetropolitan areas and those in the outlying suburbs of major metropolitan communities.

Financial resources are typically most limited in nonmetropolitan communities. Small, nonmetropolitan communities, on average, have low per capita incomes compared to larger urban communities. Incomes averaged $38,233 in metropolitan areas in 1990 (Bureau of Census, 1990). In contrast, average incomes



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--> 2 Status of Small Water Systems More than 50 million U.S. residents (nearly 20 percent of the population) obtain their water from water utilities serving fewer than 10,000 people (EPA, 1994). The communities that rely on these smaller water systems are responsible for providing the financial means to build the systems, operate and maintain them, and ensure that they meet federal drinking water standards. This chapter discusses the financial status of small communities, their track record in meeting requirements of the Safe Drinking Water Act (SDWA), and their ability to pay for needed improvements to water treatment systems and infrastructures. It also reviews existing data on outbreaks of waterborne disease in small and large communities. As discussed in this chapter, small communities are often ill-equipped to assume the financial and managerial responsibilities associated with providing high-quality water service. Financial Resource Limitations in Small Communities While every town and city is unique and not all face the same problems, many small communities have economic characteristics that make it difficult for them to raise the funds needed for adequate drinking water service. Small communities can generally be divided into two groups: those in nonmetropolitan areas and those in the outlying suburbs of major metropolitan communities. Financial resources are typically most limited in nonmetropolitan communities. Small, nonmetropolitan communities, on average, have low per capita incomes compared to larger urban communities. Incomes averaged $38,233 in metropolitan areas in 1990 (Bureau of Census, 1990). In contrast, average incomes

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--> were $25,785 in nonmetropolitan communities with fewer than 1,000 residents, $28,872 in nonmetropolitan communities with 1,000 to 2,499 residents, and $29,192 in nonmetropolitan communities with 2,500 to 9,999 residents. Small nonmetropolitan communities also tend to have higher unemployment rates and a larger proportion of aging residents than urban communities. The average unemployment rate in urbanized areas in 1990 was 4.9 percent, while in communities of 2,500 to 9,999 located outside of urbanized areas the average unemployment rate was 7.5 percent (Bureau of Census, 1990). A study in Virginia showed that throughout the 1980s, unemployment in nonmetropolitan areas was consistently more than 50 percent higher than in metropolitan areas (Virginia Water Project, 1994). This same study showed that 13 percent of the residents of nonmetropolitan areas in the state were over age 65, as compared to 9 percent of the population in metropolitan areas. The age demographics of small nonmetropolitan communities reflect a historical trend of younger generation increasingly migrating to larger cities in search of jobs. For example, in 1880, 75 percent of Americans lived in rural areas, but now 75 percent live in urban areas (Lindsey, 1995). Adding to the financial difficulties of small nonmetropolitan communities, lenders are less willing to loan to rural communities than to metropolitan ones because of the increased effort needed to monitor smaller loans relative to the profits they generate. Rural banks often prefer to invest in government securities rather than in local efforts because of the need to diversify their risks (Lindsey, 1995). A shortage of loan capital is an especially significant problem for privately owned small water systems because they are not eligible to receive the government grants available to some publicly owned systems. Some small water systems are located in or near metropolitan areas, where they could be, but often are not, connected to a major municipal water supply. An example of such a system is one that until recently served the town of Aroma Park, Illinois, which is 50 miles from Chicago and only 2 miles from a major water utility serving cities south of Chicago (see Box 2-1). Small water systems located in metropolitan communities are becoming an increasingly common phenomenon as city residents migrate to new housing developments in suburban and periurban areas. The private developers who build these new communities may purposefully avoid acquiring water service from the central city in order to save on development costs. The water purveyor is initially the developer, but once the development is complete, responsibility shifts to a homeowners' association, which may be poorly equipped to manage water service. An example of a region with a large number of small systems in a metropolitan area is Kitsap County, Washington (see Box 2-2). Whether a small community is located in a metropolitan area or a nonmetropolitan one, it will lack the economies of scale of larger communities in providing water service. The small ratepayer base available in small communities means

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--> BOX 2-1 Small Water Supply System Near Chicago The Village of Aroma Park, Illinois, is located approximately 50 miles south of Chicago. Prior to 1944, the source of water for this municipal system, which serves approximately 700 people, was two wells. During periods of low precipitation, this supply was diminished, and the village was forced to institute water use restrictions. The village water system investigated additional ground water supplies, but these other ground water sources were not adequate. The cost to provide a surface water plant was excessive. In 1994, the village and Consumers Illinois Water Company (CIWC), an investor-owned water utility using a major surface water source and serving the nearby larger communities of Kankakee, Bradley, and Bourbonnias (combined population of approximately 60,000), worked together to extend a 12-in.-diameter main approximately 2 miles from the main CIWC system to the Aroma Park system. The village now receives a reliable, ample supply of water from CIWC and has retained its employees and the ownership of its system. The project, which cost approximately $300,000, was funded half by a state grant obtained by the village and half by CIWC. In addition to residents of Aroma Park, a number of rural and suburban residents along the route of the new main have connected to the new main and enjoy improved water service and fire protection. that per capita water rates must be higher than in larger, urban communities in order to provide the same level of service. Small pipes, tanks, and pumps cost more per unit of water delivered than the larger sizes. For example, the per capita capital cost of a conventional water treatment plant with a maximum flow capacity of 0.01 m3/s (0.23 million gallons per day), which would be adequate for a population of about 1,500, is more than three times as high as the per capita cost for a system with a maximum flow capacity of 0.1 m3/s (2.3 million gallons per day), which would be adequate for a population of approximately 15,000 (McMahon, 1984; Montgomery, 1985). Thus, residents of very small communities might pay more than three times as much to finance construction of a new water treatment plant as residents of larger towns. Similarly, paying staff to operate and maintain small water systems is much more costly per unit of water delivered than paying staff to run larger systems. In one small Connecticut community, capital and operating improvements to a failing water system would have increased residential water rates nearly sevenfold per year, from $144 to $1,000. When this system merged with a large one, the community's residents obtained better quality water or $269 per year instead of $1,000 per year because their capital and operation and maintenance costs were spread across a much larger service area (EPA, 1989a). The limitations in financial resources available to many small communities for water service create a variety of problems. In the most extreme instances, residents of small communities may lack running water altogether. As of 1990,

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--> BOX 2-2 Proliferation of Urban Small Systems in Kitsap County, Washington Washington State has experienced almost a 24 percent increase in population over the last 10 years. This rapid growth has occurred primarily in proximity to urban centers, but largely in areas where services and infrastructures were not available. While Washington has been a leader in promoting comprehensive planning and the concept of water service areas with sole providers, there has been a proliferation of small systems over the past ten years, not only in the rural areas but even more so in the suburban areas and urban fringes. Kitsap County is one example of a highly populated area where the number of small water supply systems has increased in recent years. The county is one of four that make up the greater Puget Sound metropolitan area, which includes the urban corridor from Everett (Snohomish County) to Tacoma (Pierce County), with Seattle (King County) in between. Although land-use patterns indicate that a large part of Kitsap County is rural and forested, the county is second only to King County in population density of all counties in Washington State; in 1995, the population density was 582 persons per square mile. Despite Kitsap County's proximity to major metropolitan centers and its high population density, the number of regulated water systems that must meet SDWA requirements (15 connections or more) increased from 216 in 1987 to 255 in 1995. Water systems with 3 to 14 connections increased from 453 in 1987 to 810 in 1995. Factors driving the increase in small water systems in Kitsap County include the costs of connecting to an existing system and, perhaps more importantly, state water allocation policies. Water rights are required for larger systems to increase their allocations to provide additional service connections. They are not required for smaller systems. It currently can take up to 5 years for allocation decisions (yes or no) to be made. This state water resource policy failure has had severe impacts on attempts to stop the proliferation of small systems, particularly in areas that have above-average county population densities. In 1995, the state legislature passed a bill that requires new water systems to be owned or managed by satellite operators certified by the state if the community cannot be served by an adjacent, preexisting utility. This should help stop the proliferation of small systems. more than 1.1 million U.S. households lacked plumbing, according to the U.S. Census Bureau. Of these 1.1 million households, approximately 760,000 are located in communities with populations of less than 10,000. Lack of water service may result not just from the absence of household plumbing and water mains to the community but also from seasonal inadequacies in the water source and infrastructure failure because of poor operation and maintenance. Low water pressure, caused by an inadequate or intermittent supply, may have serious consequences for water quality because it can allow contaminants to infiltrate the water through leaks in the pipes. Backsiphonage of contaminants into water pipes during periods of low pressure has caused dozens of waterborne disease

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--> BOX 2-3 Water Supply Problems in a Small Pennsylvania Town Residents of the Village of Onnalinda, in Cambria County, Pennsylvania, have had to boil their drinking water for more than a year. The village water system provides water to residents from a reservoir on a tributary of the Little Conemaugh River. Until the chlorinator broke, the water was disinfected just before it entered the village. However, when the chlorinator broke and the village could not afford to replace it, residents were advised to boil their water. The water system ceased all water quality monitoring at this time, claiming lack of financial resources. The utility claimed it would also be unable to afford installation of a filtration system, which is now required for all water systems using surface water sources. In addition to these problems, many of the pipes in the water system are old and require replacement. A 1994 study by the Redevelopment Authority of Cambria County concluded that Onnalinda's water supply problems could best be solved by connecting to a nearby larger water utility, the Highland Sewer and Water Authority (Pellegrini Engineers, 1994). The study estimated the total costs of this project at $286,000, or nearly $16,000 for each of the village's 18 homes. The Highland Sewer and Water Authority concluded that in order to take over the system, it would need a grant or other attractive offer because on its own the Onnalinda system would not generate enough income to pay for the project. outbreaks over the past two decades (Craun, 1996). While data on water quality failures are readily available, data on service failures are not routinely acquired by any agency. While most small communities in the United States do have access to running water, they often cannot afford to construct the facilities or maintain the staff needed to ensure compliance with the SDWA. In addition, small communities may be unable to replace corroded distribution piping and other failing or substandard infrastructure. Further, they may lack the resources needed to develop and carry out the detailed planning necessary for long-term improvements to their water service. The town described in Box 2-3 illustrates these types of problems. Compliance with the Safe Drinking Water Act in Small Communities The limited resources available to small communities can create difficulties in complying with the SDWA. The SDWA regulates two broad types of contaminants: microbiological and chemical. Analysis of U.S. Environmental Protection Agency (EPA) data on SDWA compliance shows that small communities, especially those with fewer than 500 people, often have difficulty in meeting the requirements for microbiological contaminants and have more difficulty than large communities in meeting requirements for chemical contaminants.

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--> Compliance with Microbiological Standards Waterborne diseases—caused by microorganisms that enter water sources from the wastes of infected humans and animals—have been largely but not entirely eliminated in the United States and other industrialized countries, thanks in part to better protection of water sources and wider use of water treatment systems. While in recent years the public and federal policymakers have placed more emphasis on chemical contaminants than on microbiological ones, publicity surrounding a 1993 epidemic in Milwaukee brought national attention to the risk of waterborne pathogens. An estimated 403,000 Milwaukee residents contracted cryptosporidiosis (severe, prolonged diarrhea caused by the parasite Cryptosporidium) via the city's drinking water supply (MacKenzie et al., 1994). Public health investigators estimated that more than half of those who obtained their water from the contaminated supply became ill (MacKenzie et al., 1994), and deaths due to cryptosporidiosis were reported among patients with compromised immune systems. Health investigators estimated that this outbreak cost the city more than $133 million in direct medical costs (such as those for hospital and clinical treatments) and indirect medical costs (such as those associated with lost wages) (P. A. Shaffer, Centers for Disease Control, personal communication, 1996). The microbiological quality of drinking water is regulated under the SDWA by requiring water systems to monitor for coliform bacteria, which indicate the possible presence of fecal contamination and disease-causing organisms (see Box 2-4). Table 2-1 shows the number of community water systems that violated the maximum contaminant level (MCL) for total coliforms by size of community and water source (ground or surface) for the 27-month period October 1, 1992, through December 31, 1994.1 Most of the systems in violation were in ground water systems serving 500 or fewer people, presumably because many of these systems do not disinfect their water. The violation rate for system with fewer than 500 customers is more than twice the rate for systems serving larger populations: a violation of the MCL for total coliforms was reported by 29.5 percent of the systems serving fewer than 500 people as compared to less than 14.5 percent of the systems serving larger communities. The large number of small community water systems in violation of the SDWA poses a serious management problem for state regulatory agencies. As 1   A large number of systems fail to follow EPA requirements for contaminant monitoring, so the actual number of systems in violation could be much higher than shown in Table 2-1. In 1993, for example, 26 percent of water systems serving 500 or fewer people, 20 percent of those serving 501 to 3,300 people, 37 percent of those serving 3,301 to 10,000 people, and 26 percent of those serving larger communities violated one or more of EPA's monitoring and reporting requirements (EPA, 1994).

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--> BOX 2-4 Monitoring the Microbiological Quality of Drinking Water A wide variety of bacteria, viruses, and parasites can cause illness when present in drinking water. However, because monitoring for each of the possible waterborne disease agents is technically difficult, coliform bacteria have been used for many decades as an indicator of the microbiological quality of drinking water. Rather than requiring water systems to monitor for all possible types of waterborne pathogens, SDWA regulations require that systems check for the presence of coliform bacteria. These bacteria are present in the normal intestinal flora of humans and other warm-blooded animals and are found in large numbers in fecal wastes. Most species of coliforms are also free-living in the environment. Thus, their presence in drinking water does not necessarily represent fecal contamination. However, finding coliform bacteria in a drinking water system indicates possible fecal contamination due to inadequate water treatment or deficiencies in the distribution system. In 1977, the EPA issued regulations for total coliforms in drinking water, establishing an MCL based on coliform density, monitoring requirements, and analytical method used (EPA, 1976). A revised regulation, which became effective on December 31, 1990 (EPA 1989b), specifies an MCL based on the presence of coliforms in a 100-ml water sample: coliform bacteria can be detected in no more than 5.0 percent of the samples collected during a month; systems collecting fewer than 40 samples per month may have no more than one positive sample without violating the MCL. The revised regulation specifies a monitoring frequency based on the number of people served and requires additional monitoring whenever a positive sample occurs. For example, systems serving 25 to 1,000 people need collect only one coliform sample per month, while systems of 1,001 to 2,500 and 2,501 to 3,300 consumers must collect two and three samples per month, respectively. A maximum of 480 samples per month is required of systems serving more than 3,960,000 people. shown in Table 2-1, 96 percent (13,039 of 13,526) of the systems in violation serve communities with 10,000 or fewer people. While it is generally presumed that coliform-free water contains few or no pathogens and is therefore unlikely to cause waterborne disease, the risk of infectious waterborne disease may be greater than is suggested by the number of violations of the MCL for total coliforms. Waterborne disease outbreaks, especially those caused by disinfectant-resistant organisms such as Giardia and Cryptosporidium, have occurred in water systems that have not violated the coliform MCL (Craun, 1984, 1990a; Moore et al., 1994; Kramer et al., 1995). For example, the 1993 outbreak in Milwaukee and an outbreak in Las Vegas in 1994 occurred even though both cities were in compliance with the coliform MCL (MacKenzie et al., 1994; Goldstein et al., 1996). Thus, federal data on violations of coliform standards may understate the degree to which drinking water supplies are contaminated with pathogenic organisms.

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--> TABLE 2-1 Number of Community Water Systems that Violated the Maximum Contaminant Level for Total Coliform Bacteria Between October 1, 1992, and December 31, 1994   Size of Population Served by Water System   500 and Under 501–3,300 3,301–10,000 10,001 and Over Total Surface water systems 524 294 167 199 1,184 Ground water systems 9,985 1,644 425 288 12,342 Total number of systems with violations 10,509 1,938 592 487 13,526 Percentage of systems with violations 29.5 13.4 14.4 14.4 23.5   SOURCE: Federal Reporting Data System (data summaries provided by Jeff Sexton, EPA). Compliance with Chemical Standards A major factor leading to passage of the SDWA was public concern about contamination of the environment with man-made chemicals that, over long periods of exposure, can lead to cancer and other chronic diseases. Thus, the SDWA requires the EPA to set MCLs for dozens of chemical contaminants. With the exception of nitrate and nitrite, which can cause acute methemoglobinemia, the MCLs for chemicals are based on the prevention of adverse health effects associated with long-term, low-level exposures (see Box 2-5). Tables 2-2, 2-3, and 2-4 show the number of community water systems with violations of chemical MCLs for the 27-month period October 1, 1992, through December 31, 1994. Table 2-2 shows violations by individual contaminant for systems using ground water as a water source; Table 2-3 shows violations for systems using surface water; and Table 2-4 summarizes the data from these tables and shows the percentage of systems in violation for various sizes of water systems. As documented in Table 2-4, the likelihood that a water system will violate chemical MCLs is a function of the size of the system. The violation rate for systems serving 500 or fewer people is more than triple the rate for systems serving populations of greater than 10,000 people. While the rate of violation of chemical standards appears to be low based on these data, the actual violation rates are likely higher than the data show because violations are not always reported. According to EPA data, 11 percent of systems serving 500 or fewer

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--> BOX 2-5 Assessing Risks of Chemical Contaminants Understanding the nature of risks associated with long-term, low-level exposures to chemical contaminants requires knowledge of how MCLs are established. Although human health effects data are used when available, this information is sparse for most chemicals. The MCLs are derived almost exclusively from toxicological studies on animals in combination with an analysis of the technical feasibility of monitoring for and removing the contaminant in question. Risk assessments used to establish health effects of a chemical are based on one of two approaches, depending on whether the chemical is considered to cause cancer (i.e., every dose has a risk) or not (i.e., there is a threshold dose below which no effect is expected). For chemicals not suspected to cause cancer, either the dose at which no detectable adverse health effect occurs or the lowest dose at which an adverse effect is detected can be used in establishing an MCL. For carcinogens, MCLs are generally based on the estimated risk of one additional cancer per 100,000 to 1 million people exposed over a lifetime. A number of uncertainties are associated with these risk assessments, including the quality and quantity of the available health data, extrapolation of toxicological data from high to low doses and from animals to humans, and assumptions used to derive the quantitative risk estimates (ingestion of 2 liters of water per day is assumed for a lifetime of 70 years, and exposure from drinking water must be estimated relative to exposure from other sources). Thus, the MCLs, although they are legal requirements, should be considered only crude indications of the actual health risk associated with long-term exposure to any chemical. It should be recognized that the use of large uncertainty factors for nonthreshold chemicals and conservative estimates for cancer risks generally ensures that moderate short-term exposure to levels exceeding the MCL will not significantly increase the risk of disease. customers failed to meet monitoring and reporting requirements for chemical contaminants in 1994–1995; approximately 6 percent of systems serving 501 to 10,000 customers failed to meet these requirements (EPA, 1995). Table 2-2 shows that for small systems using ground water, the most common individual chemical contaminant is nitrate. Of the 646 small ground water systems with reported violations, 463 (72 percent) had problems meeting the standards for nitrate. The second leading problem for these systems was fluoride, which was reported as a problem by 57 (8.8 percent) of the small ground water systems with violations. As a group, man-made organic chemicals (including all of the contaminants included in phase I of the SDWA regulations and some of those included in phase II) were reported as problems by 81 (13 percent) of the small ground water systems with violations. Table 2-3 shows that for small systems using surface water, the leading chemical contamination problem is atrazine. Atrazine violations were reported by 37 (51 percent) of the 72 small surface water systems with violations. Nitrate was the second leading cause of chemical contamination for small surface water

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--> TABLE 2-2 Number of Ground Water Systems that Violated Drinking Water Standards for Chemical Contaminants Between October 1, 1992, and December 31, 1994   Size of Population Served by Water System Chemical 500 and Under 501–3,300 3,301–10,000 10,001 and Over Individually regulated contaminants Arsenic 5 Fluoride 48 9 1 Lead (prior to distribution system) 1 Phase I contaminants Benzene 8 1 Carbon tetrachloride 3 1,2-Dichloroethane 2 1,1-Dichloroethylene 7 3 1,1,1-Trichloroethane 4 Trichloroethylene 14 3 3 1 Vinyl chloride 3 1 Phase II contaminants Barium 6 5 Cadmium 2 1 1,2-Dichloropropane 3 1 Ethylene dibromide 3 1 Monochlorobenzene 1 Nitrate 369 87 7 2 Nitrite 1 Selenium 20 6 Tetrachloroethylene 13 3 2 1 Total number of systems with violations 512 119 15 5 NOTE: Only contaminants for which violations occurred are included on this list. Also, contaminants for which regulations did not yet apply to small systems during the period covered by this table are excluded from the list. SOURCE: Federal Reporting Data System (data summaries provided by Jeff Sexton, EPA).

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--> TABLE 2-3 Number of Surface Water Systems that Violated Drinking Water Standards for Chemical Contaminants Between October 1, 1992, and December 31, 1994   Size of Population Served by Water System Chemical 500 and Under 501–3,300 3,301–10,000 10,001 and Over Individually regulated contaminants Fluoride 1 2 Phase 1 contaminants (VOC rule) 1,1,1-Trichloroethane 1 Trichloroethylene 1 2 Phase II contaminants Atrazine 8 23 6 1 Chromium 1 Ethylene dibromide 2 1 Mercury 1 Nitrate 7 13 4 6 Tetrachloroethylene 1 1 Total number of systems with violations 19 43 10 10 NOTE: Only contaminants for which violations occurred are included in this list. Also, contaminants for which regulations did not yet apply to small systems during the period covered by this table are excluded from the list. SOURCE: Federal Reporting Data System (data summaries provided by Jeff Sexton, EPA). TABLE 2-4 Violations of Drinking Water Standards for Chemical Contaminants by Size of Water System: Summary Data for the Period October 1, 1992, to December 31, 1994   Size of Population Served by Water System Source of Water 500 and Under 501–3,300 3,301–10,000 10,001 and Over Ground water 512 119 15 5 Surface water 19 43 10 10 Total number of systems with violations 531 162 25 15 Percentage of systems with violations 1.5 1.1 0.61 0.44   SOURCE: Tables 2-2 and 2-3.

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-->

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--> TABLE 2-5 Infectious Waterborne Disease Outbreaks Caused by Contaminated Drinking Water Systems in the United States, 1971–1994 Etiologic Agent Type of Organism Outbreaks Cases of Illness Giardia lamblia Parasite 113 26,670 Shigella Bacteria 40 8,962 Norwalk-like virus Virus 20 10,552 Hepatitis A Virus 28 827 Campylobacter Bacteria 15 5,459 Salmonella Bacteria 13 2,995 Cryptosporidium parvum Parasite 10 419,934a All others (toxigenic E. coli bacteria, Yersinia bacteria, rotavirus, S. typhi bacteria, V. cholerae bacteria, and others)   15 3,263 Unidentified etiologies   325 81,554 TOTAL   579 560,421 a Of these cases, 403,000 were from a single outbreak in Milwaukee. SOURCE: Compiled from CDC and EPA data in CDC, 1973, 1974, 1976a,b 1977, 1979, 1980, 1981, 1982a,b, 1983, 1984, 1985; St. Louis, 1988; Levine et al., 1990; Herwaldt et al., 1991; Moore et al., 1993; Kramer et al., 1996a,b. and nausea followed by jaundice. As shown in the table, the pathogen causing the illness is unidentified for more than half of the outbreaks. Table 2-6 shows incidents of acute chemical poisoning caused by drinking water contamination between 1971 and 1994. Copper and fluoride were the most frequently identified chemicals causing acute illness—usually vomiting within a short time after consuming the water or using it in beverages. The source of copper in these outbreaks was leaching from plumbing and water service pipes due to corrosive water (a problem that can be controlled with proper water treatment). The source of fluoride was various operational and technological deficiencies in the equipment used to fluoridate the water to prevent dental problems. Two deaths occurred as a result of high fluoride levels. Other deaths included two attributed to arsenic contamination of a private well, one caused by high levels of nitrate in a private well, and one resulting from high levels of ethylene

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--> TABLE 2-6 Chemicals Associated with Waterborne Outbreaks of Acute Illness in the United States, 1971–1994 Chemical Community Water Systems Noncommunity Water Systems Individual Water Systems Total Number of Outbreaks Copper 13 2 2 17 Fluoride 7 5 0 12a Nitrate 0 0 7 7 Oils 4 1 0 5 Chlordane 4 0 0 4 Lead 1 0 5 6 Ethylene glycol 2 0 0 2 Sodium hydroxide 2 0 0 2 Arsenic 0 1 1 2 Unidentified herbicide 2 0 0 2 All othersb 7 0 5 12 TOTAL 42 9 20 71 a Includes an outbreak where high levels of both fluoride and copper were present. b Single outbreaks caused by ingestion of selenium, phenol, benzene, PCB, gasoline, chromium, trichloroethylene, ethyl acrylate, morpholine, or hydroquinone and a dermatitis outbreak due to high levels of chlorine. SOURCE: Compiled from CDC and EPA data in CDC, 1973, 1974, 1976a,b, 1977, 1979, 1980, 1981, 1982a,b, 1983, 1984, 1985; St. Louis, 1988; Levine et al., 1990; Herwaldt et al., 1991; Moore et al., 1993; Kramer et al., 1996a,b. TABLE 2-7 Causes of Waterborne Outbreaks of Acute Chemical Illness in the United States, 1971–1994   Cause of Outbreak Type of Water System Ground Water Contamination Treatment Deficiencies Distribution or Storage Deficiencies Unidentified Deficiencies Community 4 7 29 2 Noncommunity 1 4 3 1 Individual 12 1 5 2 All systems 17 12 37 5   SOURCE: Compiled from CDC and EPA data in CDC, 1973, 1974, 1976a,b, 1977, 1979, 1980, 1981, 1982a,b, 1983, 1984, 1985; St. Louis, 1988; Levine et al., 1990; Herwaldt et al., 1991; Moore et al., 1993; Kramer et al., 1996a,b.

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--> glycol from a cross-connection. As shown in Table 2-7, 52 percent of acute illnesses due to chemical contamination were caused by contamination of the water distribution system, either by cross-connections, backsiphonage, or corrosive water. In addition, 24 percent of the outbreaks were caused by ground water contamination, often with nitrate. While these data show that waterborne disease is still a problem in the United States, health experts generally agree that the number of reported outbreaks represents only the tip of the iceberg. For a variety of reasons, the scope and quality of the available data are highly variable. Problems with the interpretation of these data include the following: Some states have weak disease surveillance systems. As a consequence, waterborne disease outbreaks may have occurred in these states without being recognized and investigated by state officials. Even where adequate disease surveillance systems are in place, health officials may not recognize small outbreaks or recognize that water is the route of disease transmission for endemic diseases. When low levels of waterborne pathogens are present, sporadic cases of infection may occur at various times and points throughout the water distribution system and never be recognized as an outbreak because it is difficult to separate these cases from background levels of disease. Only a small proportion of people who develop diarrhea illness, which is sometimes caused by waterborne infections, seek physician assistance. Not all outbreaks are adequately investigated. Outbreaks are included in the EPA and CDC database only if water quality and/or epidemiologic data are collected to document water as the route of disease transmission. States do not always report waterborne disease outbreaks to the CDC. As mentioned above, reporting of disease outbreaks to the federal government is voluntary. The data do not reflect the risks of long-term, low levels of exposure to chemical contamination, only the cases of acute chemical poisoning. Consumption of water with levels of a carcinogen higher than the established MCL can theoretically increase the potential cancer risk for the exposed population, especially as the duration of exposure and concentration of the carcinogen increase. However, scientists are usually unable to accurately quantify this risk for the specific population that may be exposed. The same is true for potential teratogens. Although public health officials acknowledge that the incidence of waterborne disease is much higher than the reported waterborne outbreak statistics indicate, the actual incidence is difficult to estimate. Few studies have attempted to quantify the extent of underreporting of waterborne outbreaks and associated disease. Limited evidence suggests that anywhere from 50 to 90 percent of waterborne outbreaks may be unreported (Craun and McCabe, 1973; Craun,

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--> 1990b). Furthermore,the extent to which endemic disease is associated with drinking water is unknown. An epidemiologic study in the Montreal area attributed 35 percent of mild, unreported cases of diarrhea to the consumption of tap water that met water quality regulations (Payment et al., 1991). In Vermont, waterborne transmission was suggested to be an important cause of non-outbreak-related giardiasis, as rates of infection were almost twice as high in persons receiving unfiltered versus filtered municipal water (Birkhead and Vogt, 1989). Although the number of waterborne disease outbreaks is greater for small systems, available data do not indicate whether small water systems experience a higher percentage of outbreaks than larger systems (Craun and McCable, 1973; G. F. Craun, Global Consulting for Environmental Health, unpublished data, 1993). Analyses of differences in the occurrence of waterborne disease between small and large communities are complicated by outbreak and disease reporting differences. Detection and investigation of outbreaks may differ between large and small communities. In small communities, for example, waterborne disease outbreaks may not be recognized because of the small number of people affected. Adequacy of Water Treatment and Distribution Systems in Small Communities Public health officials have long advocated a ''multiple barrier" approach to disease prevention, and drinking water treatment and distribution systems are key components of this approach. The multiple barriers to waterborne disease include selection of the purest sources of water; protection of both ground and surface water sources from municipal, agricultural, and industrial pollution; appropriate treatment of drinking water; effective operation and monitoring of drinking water treatment facilities; and prevention of contamination during the storage and distribution of treated water. As the U.S. population continues to increase and put pressure on natural resources, finding high-quality source water will become more difficult, and water treatment system will increase in importance as a barrier to waterborne illnesses. Failures and weaknesses in this barrier leave small communities more vulnerable to outbreaks of waterborne disease. Many small water systems require major upgrades to their treatment and distribution systems. A recent EPA survey of 600 small systems selected at random from around the United States revealed major deficiencies in drinking water treatment (Fraser et al., 1995). Some of the surveyed systems using surface

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--> water disinfect but do not filter their water, putting consumers at significant risk of exposure to waterborne pathogens, particularly disinfectant-resistant protozoa such as Giardia and Cryptosporidium. Many of the small surface water systems that do provide filtration use turbid sources of water with inadequate filtration. For example, one system in Wyoming must issue boil water advisories for long periods each spring because its filtration system is not adequate to purify the extremely turbid spring runoff water. Ground water systems using water with high concentrations of iron and manganese often lack adequate equipment for removal of these metals, which can cause foul tastes and odors and clog pipes. In some small ground water systems, high concentrations of total dissolved solids make the water unpalatable or even undrinkable. The EPA survey also found that maintenance of water treatment and distribution systems is often poor in small communities. The survey found frequent instances of facilities that, although within their service life, are inoperable because of lack of maintenance. In many of the small systems surveyed, equipment such as chemical pumps, turbidimeters, and pH monitors is broken. Water distribution lines are often substandard or have not been replaced for many decades or even a century. One system distributes water through garden hoses. Others have small-diameter galvanized steel water mains that are completely corroded. Maintenance in some plants is so poor that the entire plant needs to be replaced to make the system reliable. Improving deteriorating or inadequate water treatment and distribution facilities is the responsibility of local authorities, whether village, town, city, or county governments, or, in the case of private developments, the owner of the development. Many small communities lack the resources to initiate, let alone carry out, the steps necessary to upgrade their water service and would be obliged to call on the state for assistance even when only a simple treatment technology is required. However, as discussed in Chapter 1, most state agencies lack the resources to provide the detailed technical assistance necessary at the local level. As a consequence, small communities with poorly performing water systems can have difficulty in obtaining the help they need to improve their water service. In addition, state regulators may be unable to provide the oversight needed to ensure that small water systems are properly maintained. Diversity of Local Water Supply Agencies Originally, most local water supply service was provided privately by entrepreneurs who saw financial opportunity in filling the need for a necessary service. However, in the late nineteenth and early twentieth centuries, as many private enterprises failed for lack of adequate capital resources to keep up with population growth, or for other reasons, local governments began to take over these utilities, especially in larger communities. As shown in Table 1-2, most

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--> very small systems are still privately owned, but most systems serving 500 or more people are now publicly owned. Various arrangements are commonly found for providing water supply services in smaller communities: The water supply system is owned and operated by the local authority, which may be most commonly the incorporated community, village, town, city, county, or regional government that serves the small community systems and individual householders within its jurisdiction. The water purveyor is initially the developer of a suburban community, but when the development is complete, responsibility for the water service may become that of a homeowners' association of some type. The movement of populations to suburban and periurban areas has led to private developers being responsible for the creation of free-standing residential communities; developers often purposefully avoid acquiring water service from the central city for financial reasons. The water supply is owned and operated by the owner of a mobile home park. In such situations, the capital costs of water supply (and sewerage) facilities are a much larger fraction of the overall costs of the residences than in conventional single-family housing communities. The residents of mobile home parks, in addition, are more severely constrained in borrowing for such facilities. The community, which may have built and initially operated its water supply system, contracts to a private company some or all of its responsibilities for managing the system. The contracting out of specific tasks such as meter reading, billing, and analytical work to meet water quality monitoring obligations are examples of this practice. The water utility, including all of its capital facilities, is owned and operated by a private investor-owned company, generally one that owns and operates small systems throughout a region or throughout the United States. A community in the vicinity of a larger city arranges for service from that city. The larger city may provide all of the infrastructure and deal with individual customers in the outlying community from the outset. More commonly, a small community will provide its own distribution system, often following the guidelines and standards of the larger city, and arrange to purchase raw or treated water wholesale from the larger city but be responsible for dealing with individual customers. In time, the smaller community may be absorbed into the service area of the larger one. Complexity of Improving Water Service Regardless of who owns the water system, improving or providing new water supply service requires a series of complex steps. These steps may be

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--> beyond the capability of small communities, especially those without links to larger utilities. The first step in improving water supply service is planning (see Chapter 5). This involves developing quantitative information about the future population, water users, water demand, current and future yield of water sources, quality of the sources, treatment methods for the sources, environmental consequences associated with the water supply (including creating the need for additional sewerage), financing, and capital and operating costs. It also requires establishment of the mechanisms for obtaining the necessary engineering services and selecting engineers for design and construction. The second step in improving water service is designing the system improvements. Even if package plants are being considered, the community will need to retain a design engineer for tasks such as selecting the water source, designing the transmission and distribution system lines, designing the reservoir, and selecting the most appropriate package plant from amongst the many available options. The third step in upgrading water service is constructing the new system. It is common for a community consulting engineer to help negotiate the contract for construction of the facilities with a general contractor. In cases where all design and construction work is purchased in a package, a community representative or paid staff person must supervise construction to ensure that the design and specifications are fully met by the contractor. The final step in upgrading water service is to provide for adequate operation, maintenance, and management of the system. Large communities usually employ large staffs—including a manager, one or more engineers, a chemist and/or microbiologist, laboratory technicians, one or more plant operators, maintenance personnel for the distribution system and treatment facilities, meter readers, clerical personnel, customer service representatives, and drivers—to manage their water systems. While the chemistry and microbiology involved in small water supply systems are little different from those of larger systems, the staff resources for small communities are far more limited. In small systems, it is not uncommon for one part-time individual to manage the system alone. In sum, improving water supply service is a complex task that many small communities are unable to handle on their own. Conclusions While waterborne disease in the United States is far less prevalent now than it was at the turn of the century, U.S. public water supplies still face significant difficulties. Small communities face special problems in supplying high-quality drinking water because many of them cannot afford the technologies or trained personnel needed to meet federal drinking water standards. As the population continues to increase and sources of clean water become harder to find, the safeguards provided by properly operated, modern water treatment technologies

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--> will become increasingly important in communities of all sizes. Yet, small communities are often ill equipped to arrange for improvements to their water service. A sustained national effort is needed to ensure that small communities have the support they need to provide an adequate quantity of water that meets the standards of the SDWA. In particular, policymakers need to address the following issues: Small communities have economic characteristics that make it difficult for them to raise the funds needed for adequate water supply service. Small communities, especially those in nonmetropolitan areas, may have relatively low per-capita incomes, high unemployment rates, large populations of elderly residents, and limited access to capital for loans. In addition, because of their small ratepayer bases, per-person water rates in small communities must be higher than those in large communities in order to provide the same level of service. Small water systems, especially the very small ones, have difficulty complying with SDWA requirements for microbiological and chemical contaminants. Systems serving fewer than 500 people exceeded MCLs more than twice as often as those serving more than 10,000 people. Many small water systems require major capital investments to upgrade their treatment systems and infrastructure. Many small systems not only lack the treatment facilities needed to meet regulatory requirements but also have broken equipment or corroded or substandard distribution lines that need to be replaced. These small systems could benefit from technical assistance from state water supply regulators, but state agencies generally lack the resources to provide the detailed assistance that would most benefit small systems. Failure to provide adequate water treatment and to comply with drinking water standards leaves small communities vulnerable to outbreaks of waterborne illnesses. More than 600 outbreaks of waterborne disease have been reported in the United States in the past two decades; these reported outbreaks represent only a fraction of the total incidence of waterborne disease because many outbreaks are unrecognized or unreported. References Birkhead, G., and R. S. Vogt. 1989. Epidemiologic surveillance for endemic Giardia lamblia infection in Vermont. American Journal of Epidemiology 129(4):762–768. Bureau of Census. 1990. 1990 Census of Population: Social and Economic Characteristics. Washington, D.C.: Department of Commerce. CDC (Centers for Disease Control). 1973. Foodborne Outbreaks, Annual Summary, 1972. Publication No. (CDC) 74-8185. Washington, D.C.: Department of Health, Education, and Welfare. CDC. 1974. Foodborne and Waterborne Outbreaks, Summary, 1973. Publication No. (CDC) 75-8185. Washington, D.C.: Department of Health, Education, and Welfare. CDC. 1976a. Foodborne and Waterborne Outbreaks, Summary, 1974. Publication No. 76-8185. Washington, D.C.: Department of Health, Education, and Welfare.

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--> CDC. 1976b. Foodborne and Waterborne Outbreaks, Summary, 1975. Publication No. 76-8185. Washington, D.C.: Department of Health, Education, and Welfare. CDC. 1977. Foodborne and Waterborne Outbreaks, Summary, 1976. Publication No. 78-8185. Washington, D.C.: Department of Health, Education, and Welfare. CDC. 1979. Foodborne and Waterborne Disease, 1977. Publication No. 79-8185. Washington, D.C.: Department of Health, Education, and Welfare. CDC. 1980. Water-related Disease Outbreaks, Summary, 1978. Publication No. 80-8385. Washington, D.C.: Department of Health and Human Services. CDC. 1981. Water-related Disease Outbreaks, Summary, 1979. Publication No. 81-8385. Washington, D.C.: Department of Health and Human Services. CDC. 1982a. Water-related Disease Outbreaks, Summary, 1980. Publication No. 82-8385. Washington, D.C.: Department of Health and Human Services. CDC. 1982b. Water-related Disease Outbreaks, Summary, 1981. Publication No. 82-8385. Washington, D.C.: Department of Health and Human Services. CDC. 1983. Water-related Disease Outbreaks, Summary, 1982. Publication No. 83-8385. Washington, D.C.: Department of Health and Human Services. CDC. 1984. Water-related Disease Outbreaks, Summary, 1983. Publication No. 84-8385. Washington, D.C.: Department of Health and Human Services. CDC. 1985. Water-related Disease Outbreaks, Summary, 1984. Publication No. 99-2510. Washington, D.C.: Department of Health and Human Services. Craun, G. F. 1984. Waterborne outbreaks of giardiasis: current status. In Giardia and Giardiasis, S. L. Erlandsen and E. A. Meyer, eds. London: Plenum Press. Craun, G. F. 1990a. Waterborne giardiasis. In Giardiasis, E. A. Meyer, ed. Amsterdam: Elsevier Science Publishers. Craun, G. F. 1990b. Review of the causes of waterborne outbreaks. Pp. 1–22 in Methods for the Investigation and Prevention of Waterborne Disease Outbreaks. EPA/600/1-90/005a. Washington, D.C.: Environmental Protection Agency. Craun, G. F. 1996. Waterborne disease in the United States. Pp. 55–77 in Water Quality in Latin America, G. F. Craun, ed. Washington, D.C.: ILSI Press. Craun, G. F., and L. J. McCabe. 1973. Review of the causes of waterborne disease outbreaks . Journal of the American Water Works Association 65(1):74. EPA (Environmental Protection Agency). 1976. National Interim Primary Drinking Water Regulations. EPA 590/9-76-003. Washington, D.C.: EPA. EPA. 1989a. Ensuring the Viability of New, Small Drinking Water Systems: A Study of State Programs. EPA-57019-89-004. Washington, D.C.: EPA. EPA. 1989b. Drinking Water: National Primary Drinking Water Regulations, Total Coliforms. 40 CFR Parts 141, 54 (124):27-544 and 142, 54 (124):27-568. EPA. 1994. The National Public Water System Supervision Program FY 1993 Compliance Report. EPA 812-R-94-001. Washington, D.C.: EPA, Office of Water. EPA. 1995. Unpublished data from the Safe Drinking Water Information System. Washington, D.C.: EPA. September 20. Fraser, D., C. Davies, and R. T. Jones. 1995. Capital needs of small systems. Journal of the American Water Works Association 87(11):32–38. Goldstein, S. T., D. D. Juranek, O. Ravenholt, A. W. Hightower, D. G. Martin, J. L. Mesnik, S. D. Griffiths, A. J. Bryant, R. R. Reich, and B. L. Herwaldt. 1996. Cryptosporidiosis: an outbreak associated with drinking water despite state-of-the-art water treatment. Annals of Internal Medicine 124(5):459-468. Herwaldt, B. L., G. F. Craun, S. L. Stokes, and D. D. Juranek. 1991. Waterborne disease outbreaks, 1989-1990. Morbidity and Mortality Weekly Report 40(SS-3):1–22. Kramer, M. H., B. L. Herwaldt, G. F. Craun, R. L. Calderon, and D. D. Juranek. 1996a. Surveillance for waterborne disease outbreaks-U.S., 1993-1994. Morbidity and Mortality Weekly Report 45(SS-1):1–33.

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--> Kramer, M. H., B. L. Herwaldt, G. F. Craun, R. L. Calderon, and D. D. Juranek. 1996b. Waterborne disease: 1993 and 1994. Journal of the American Water Works Association 88(3):66–80. Levine, W. C., W. I. Stephenson, and G. F. Craun. 1990. Waterborne disease outbreaks, 1986–1988. Morbidity and Mortality Weekly Report 39(SS-1):1–13. Lindsey, L. B. 1995. The Future in Rural America. Presentation at the Renaissance of Rural America Conference, Memphis, Tenn., March 7. MacKenzie, W. R., N. J. Hoxie, M. E. Proctor, M. S. Gradus, K. A. Blair, D. E. Peterson, J. J. Kazmierczak, D. G. Addiss, K. R. Fox, J. B. Rose, and J.P. Davis. 1994. A massive outbreak in Milwaukee of Cryptosporidium infection transmitted through the public water supply. New England Journal of Medicine 331:161–167. McMahon, L. A. 1984. 1984 Dodge Guide to Public Works and Heavy Construction, Annual Edition No. 16. Princeton, N.J.: McGraw-Hill Information Systems Company. Montgomery, J. M., Consulting Engineers. 1985. Water Treatment Principles and Design. New York: John Wiley & Sons. Moore, A. C., B. L. Herwaldt, G. F. Craun, R. L. Calderon, A. K. Highsmith, and D. D. Juranek. 1993. Surveillance for waterborne disease outbreaks-U.S., 1991–1992. Morbidity and Mortality Weekly Report 42(SS-5):1–22. Moore, A. C., B. L. Herwaldt, G. F. Craun, R. L. Calderon, A. K. Highsmith, and D. D. Juranek. 1994. Waterborne disease outbreaks in the United States, 1991 and 1992. Journal of the American Water Works Association 84(2):87–99. Payment, P., L. Richardson, J. Siemiatycki, R. Dewar, M. Edwards, and E. Frances. 1991. A randomized trial to evaluate the risk of gastrointestinal disease due to consumption of drinking water meeting current microbiological standards. American Journal of Public Health 81(6):703-8. Pellegrini Engineers. 1994. Small Water Systems Feasibility Study in Connection with the Highland Sewer and Water Authority for Redevelopment Authority of Cambria County. Altoona, Pa.: Pellegrini Engineers. St. Louis, M. E. 1988. Water-related disease outbreaks, summary, 1985. Morbidity and Mortality Weekly Report 37(SS-2):15–24. Virginia Water Project. 1994. Rural Virginia: A Profile in Diversity. Roanoke, Va.: Virginia Water Project.