REPORT TO THE CONGRESS Ill11 111111111111111 1111111111 LM103097 a\+ ‘7 -1 i> BY THE COMPTROLLER GENERAL ‘v\’ cOL OF THE UNITED STATES Unnecessary And Harmful Levels Of Domestic Sewage Chlorination Should Be Stopped Environmental Protection Agency Chlorine is frequently used to disinfect do- mestic sewage, and it is also used in industry and is discharged in various industrial wastes. Chlorinated discharges have been shown to be harmful to the aquatic environment, but they are still largely uncontrolled. In many situa- tions the use of chlorine is not needed. Ex- cept in areas of shellfish-harvesting or of un- restricted irrigation, disinfection of treated wastes usually is not needed to protect r) --swimmable waters in cold weather months, --waters rarely used for swimming, or --drinking water. When sewage disinfection is needed, present sewage chlorination practices generally result in excessive amounts of chlorine being dis- charged into waterways. More should be done to limit residuals and to promote the efficient use of chlorine in sewage disinfection. CED-77-108 AUGUST 30, 1977 COMPTROLLER GENERAL OF THE UNITED STATES WASHINGTON, D.C. 20548 B-166506 To the President of the Senate and the Speaker of the House of Representatives This report discusses the use of chlorine to disinfect domestic sewage at municipal waste treatment plants constructed under grants awarded by the Environmental Protection Agency. Chlorine is frequently used to disinfect domestic sewage. It is also used in industry and is discharged in various in- dustrial wastes. Chlorinated discharges have been shown to be harmful to the aquatic environment, but such discharges are still largely uncontrolled. We made this review to determine whether unnecessary chlorination has been stopped and whether, when disinfection is needed, municipalities and industries have prevented harmful levels of chlorine from being dis- charged into waterways. We made our review pursuant to the Budget and Accounting Act, 1921 (31 U.S.C. 53) and the Accounting and Auditing Act of 1950 (31 U.S.C. 67). We are sending copies of this report to the Director, Office of Management and Budget; the Chairman, Council on Environmental Quality; and the Administrator, Environmental Protection Agency. of the United States COMPTROLLER GENERAL'S UNNECESSARY AND HARMFUL LEVELS OF REPORT TO THE CONGRESS DOMESTIC SEWAGE CHLORINATION SHOULD BE STOPPED Environmental Protection Agency DIGEST ------ Chlorine discharges by municipal sewage treat- ment plants in the United States sometimes ex- ceed levels safe for the aquatic environment. Fish kills and water-life deterioration have resulted. Chlorine discharges, even at low- levels --roughly equivalent to a quart of laun- dry bleach in 2 million gallons of water-- have been shown to harm fish and other water life. (See pp. 3 through 5.) Municipal sewage treatment plant operators disinfect wastewater because it has been gen- erally thought to protect the public health from diseases transmitted through water. GAO found that the practice is widespread, With the possible exception of chlorine needed to protect areas of shellfish harvesting or of unrestricted irrigation with sewage, the pub- lic health benefits from chlorinating sewage are minimal. The widespread practice of sewage chlorina- tion is questionable for a number of reasons: --The relatively few incidents of disease transmitted through water in the United States generally are not serious and are al- most always transmitted through inadequately treated drinking ------ water. --Sewage disinfection is not practiced exten- sively in other industrialized countries with public health experiences similar to those in the United States. --Widespread sewage disinfection is a rela- tively recent phenomenon in the United States, with little accompanying improve- ment in public health. The Center for Disease Control has taken the official position that disinfection of sewage pro- vides little public health benefit. Tear Sheet. Upon removal, the report i CED-77-108 cover date should be noted hereon. --Epidemiological studies attempting to relate bacterial levels in swimming waters with levels of illness have been inconclusive. In particular, disinfection of treated wastes is usually not needed to protect waters that are ultimately used for drinking because these waters are purified in water treatment plants. Nor is disinfection usually required to pro- tect waters rarely used for swimming; nor is it needed to protect swimmable waters in cold weather. Disinfection should not be required unless it can be reasonably demonstrated that the public will benefit. In addition, the Environmental Protection Agency's rationale for disinfecting swimmable waters has no strong scientific basis. The States feel that the Agency has not supplied sufficient guidance to them as to when disinfection is not required. According to the Agency, the decision to chlorinate should be predicated on whether or not chlorination will protect the public health. Any decision to limit chlorination of wastewaters should be made on a case-by-case basis with consideration being given to drinking water source protec- tion, recreational water use, shellfish grow- ing, and other public health aspects. (See PP. 7 through 13.) Although the Agency could do more to prevent the unnecessary use of chlorine, it has taken steps to reduce the uncontrolled and excessive use of chlorine for wastewater disinfection. Since July 26, 1976, Agency regulations no longer require that all discharges from pub- licly owned treatment works provide a minimum level of disinfection. Because of the change, States now do not have to disinfect waste treatment plants' effluent unless it is needed to meet the States' water quality standards. The change, which allows States to determine the conditions under which they will use chlorine for disinfection, will not fully solve the problem. Officials of 25 of the States GAO contacted (50 percent) stated that they do not plan to reduce their chlo- rination requirements. Many cold weather States, including Alaska, Michigan, and Minne- sota, require continuous year-round sewage ii chlorination, with no reductions permitted during cold weather months. In addition, the Agency's water quality bacterial criteria for swimmable waters may be interpreted by the States to mean that year-round use of chlorine is required. Since the criteria are not suffi- ciently flexible to allow for less disinfection because of seasonal variations or a lack of us use of the waters by swimmers, the States may still disinfect regardless of how low the ex- posure risk to people might be. (See pp. 18 through 20.) Many sewage treatment plants use too much chlorine and have high chlorine residuals because of ine.fficient chlorination systems. Even in designing new plants, State and Fed- eral emphasis on improving chlorination effi- ciency has been inadequate. Chlorine produc- tion is energy intensive and a substantial reduction in its use would save a significant amount of energy. (See pp. 28 through 35.) RECOMMENDATIONS TO THE ADMINISTRATOR OF -----------------w---s---m------- E THE ENVIRONMENTAL PROTECTION AGENCY The Administrator, Environmental Protection Agency, should: --Revise the Agency's water quality criteria regarding the bacteria standard for swimmable waters to recognize seasonal variations and he should specifically delineate those cir- cumstances in which sewage chlorination is or is not needed to protect public health. --Include chlorine residual limitations in all National Pollutant Discharge Elimination System permits, when disinfection is judged l ” necessary for the protection of the public health, for sewage treatment plants and for all industrial dischargers of chlorinated I effluents. --Lower the limitation on chlorine residuals in powerplant effluents. --Require regional offices or the States, where appropriate, to tailor permits to Tear Sheet iii assure the use of chlorine testing and operating equipment which would signifi- cantly improve chlorination efficiency at individual treatment plants. --Incorporate key factors of efficient chlorination, such as rapid, thorough initial mixing and flow-proportional dosage adjustment, into construction review criteria for all new plant con- struction. (See pp. 20, 35, and 36.) RECOMMENDATION TO THE CONGRESS To reduce unnecessary chlorination of sewage, the Congress should amend the Federal Water Pollution Control Act Amendments of 1972 to permit exceptions from the national goal of swimmable waters to recognize those situa- tions in which waters are determined to be unswimmable because of other factors, such as heavy barge traffic, cold seasons of year, and general appearance. (See p. 20.) AGENCY COMMENTS NOT FURNISHED GAO requested written Agency comments in a letter dated January 11, 1977. Although sev- eral meetings were subsequently held with Agency officials to discuss GAO's findings and recommendations, the Agency has not submitted written comments. To avoid further delay, GAO is issuing the report without an official Agency expression of position. . iv Contents ---------- Page --- DIGEST i CHAPTER 1 INTRODUCTION 1 Chlorinated sewage and other chlorinated discharges 1 Scope of review 2 Agency comments not furnished 2 2 THE HARMFUL EFFECTS OF CHLORINATED DISCHARGFS 3 Chlorinated discharges are toxic to the aquatic environment 3 Only a small amount of suspected carcin- ogLns in drinking water are a result of sewage chlorination 5 3 UNNECESSARY SEWAGE CHLORINATION 7 Value of widespread sewage chlorination for disease control is questionable 8 Chlorination of sewage is not needed to protect swimmers during cold weather months 13 Chlorination is not needed for sewage discharges into waters rarely used for swimming 14 Chlorination of treated wastewater is usually not needed as a backup to drinking water disinfection 16 EPA could do more to discourage unnec- essary chlorination 18 Conclusions 20 Recommendations to the Administrator of EPA 20 Recommendation to the Congress 20 4 NEED TO PREVENT HARMFUL LEVELS OF RESIDUAL CHLORINE IN DISINFECTED SEWAGE AND OTHER EFFLUENTS 21 Sewage chlorination may be needed to protect shellfish-harvesting areas and when sewage is used for unre- stricted irrigation 22 Chlorine residuals in many locations are too high for safe discharge 23 Though a toxic pollutant, chlorine residuals are largely uncontrolled 25 Most toxic chlorine residuals can be removed 27 CHAPTER Page Improving plant effectiveness and efficiency permits lower chlorine residuals 28 Conclusions 35 Recommendations 35 APPENDIX I Review of epidemiological studies of disease transmission by swimming in polluted waters 37 II Alternatives to chlorine for sewage disinfec- tion- 40 III List of suggested references 42 IV Principal EPA officials responsible for activ- ities discussed in this report 48 ABBREVIATIONS EPA Environmental Protection Agency GAO General Accounting Office NPDES National Pollutant Discharge Elimination System ppb parts per billion ml milliliter Y Glossary Anaerobic Refers to life or processes that occur in the absence of oxygen. Baffle Any deflective device used to change the direction of flow or the velocity of sew- age. Carcinogen A cancer-producing substance. Chlorine contact A chamber in a waste treatment plant in chamber which effluent is disinfected by chlorine before it is discharged to receiving waters. Coliform A ‘group of bacteria recognized as an in- organisms dication of possible fecal pollution. Dechlorination The partial or complete reduction of re- sidual chlorine in water by any chemical or physical treatment. Dissolved oxygen The oxygen dissolved in water. Dissolved oxygen is necessary for the life of fish and other aquatic organisms and for the prevention of offensive odors. Effluent The wastewater discharged by an industry or municipality. Effluent Restrictions established by a State or limitations EPA on quantities, rates, and concentra- tions of chemical, physical, biological, and other constituents discharged from point sources. Epidemiology The study of diseases as they affect populations. Fecal coliform A group of organisms common to the in- testinal tracts of man and animals. The presence of fecal coliform bacteria in water is an indicator of possible fecal pollution. Nonpoint sources Sources of pollution that are difficult to pinpoint and measure. Common exam- ples include runoff from agriculture and forest lands, runoff from mining and con- struction activities, and storm runoff from urban areas. Nutrients Elements or compounds essential as raw materials for organism growth and de- velopment; e.g., carbon, oxygen, nitro- gen, and phosphorus. Pathogenic Causing or capable of causing disease. Primary waste Treatment using filtering and sedimenta- treatment tion techniques to remove about 30 per- cent of oxygen-demanding wastes. Sub- stantially all floating or settleable solids are removed. Secondary waste Treatment using biological processes to treatment accelerate the decomposition of sewage and thereby reduce oxygen-demanding wastes by 80 to 90 percent. Suspended solids Small particles of solid pollutants which are present in sewage and which resist separation from the water by conventional means. Water quality Specific concentrations of water pollut- criteria ants which, if not exceeded, are expected to allow a body of water to be suitable for its designated use. Water quality Water quality standards contain four ele- standards ments: the designated use (such as rec- reation, drinking water, fish and wildlife propagation) to be made for a body of water; criteria to protect those uses; im- plementation plans (for needed water qual- ity improvement programs); and a plan of enforcement. CHAPTER 1 INTRODUCTION ------------ CHLORINATED SEWAGE AND OTHER ~~~6RIN~~~~-DIB~~R~~~------ ------------------m-v The Federal Water Pollution Control Act Amendments of 1972, Public Law 92-500, clearly establishes the responsibil- ity of the Environmental Protection Agency (EPA) for reducing and controlling the pollution of navigable waters. The act establishes an interim national goal that, wherever attain- able, water quality should provide for the protection of fish, shellfish, and wildlife and for recreation in and on the wa- ter by July 1, 1983. It also establishes as national policy that the discharge of toxic pollutants be limited or prohib- ited and requires that effluent standards be established for toxic pollutants. In carrying out its responsibilities, EPA in 1973 in- cluded a bacterial limitation in its definition of secondary treatment of sewage. EPA had set a limit on bacterial dis- charge because it believed that discharges below the limita- tion would minimize the spread of disease. The attainment of this limitation, however, virtually required the use of chlorine in most sewage treatment facilities. In July 1976 EPA removed the limitation because of the toxic effect of chlorinated discharges on aquatic life, its concern about the public health effects of chlorinated organics, the cost of chlorine, and the energy needed to produce it. Chlorination of sewage is aimed primarily at preventing the transmission of waterborne diseases through destruction of the disease-causing bacteria and viruses. The need for sew- age chlorination is not universally agreed upon by public health officials, Unnecessary chlorination wastes energy and is also expensive. We estimate that the cost of the 200,000 tons of chlorine used for sewage disinfection in 1976 was $40 million. Chlorine is also found in industrial discharges. It has achieved major importance as an antifoulant in electric power- plants. Powerplants are estimated to add about 100,000 tons of chlorine chemicals to cooling water each year to control slime films. Such chlorinated waters are generally dis- charged intermittently. A variety of food processing indus- tries also use chlorination for equipment cleanup (slime con- trol), product wash, and can cooling. Breweries, pulp and paper mills, and plants producing chlorine may also dis- charge chlorinated effluents, as do industries using chlo- rine for cyanide removal (for example, electroplating plants). 1 SCOPE OF REVIEW Although chlorinated discharges have been found to be extremely toxic to fish and other water life, they occur widely throughout the country in disinfected sewage and other effluents. In view of the reported concern over chlorinated discharges, we reviewed the adverse effects of chlorination and EPA's efforts to reduce the discharge of chlorinated wastes. We made our review at EPA headquarters, Washington, D.C.; EPA regional offices in Seattle, Washington; Philadelphia, Pennsylvania; and Boston, Massachusetts; and at State agencies responsible for water quality in Washington, Oregon, Maryland, Pennsylvania, and California. We also examined construction review guidelines from all EPA regions. We sent question- naires to the State agencies responsible for water quality in all 50 States. In addition, we sent questionnaires to about 400 sewage treatment plants randomly selected from lists pro- vided by five geographically diverse EPA regions--Philadel- phia; Atlanta, Georgia; Chicago, Illinois; Denver, Colorado; and Seattle. The response rate was approximately 85 percent. We interviewed officials at the Center for Disease Control, U.S. Public Health Service, and various EPA laboratories as well as academic and professional experts on sewage chlorina- tion. We also obtained information on the sewage disinfec- tion practices of seven foreign countries. During the re- view, we were assisted by Dr. Murray Grant, GAO Medical Con- sultant; Dr. Frank D. Schaumburg, Head, Civil Engineering De- partment, Oregon State University; and Dr. Donald T. Lauria, Associate Professor of Water Resources Engineering at the University of North Carolina. AGENCY COMMENTS NOT FURNISHED On January 11, 1977, we forwarded a draft of this report to EPA and requested the Agency's written comments within 30 days. Although we subsequently met several times with Agency officials to discuss our findings and recommendations, the Agency has not submitted written comments. To avoid further delay, we are issuing the report without an official Agency expression of position. CHAPTER.2 -------- THE HARMFUL EFFECTS OF CHLORINATED DISCHARGES ----_l----l_---------~~~~~-~-~-~--~------ Chlorinated discharges are extremely harmful to creatures which live in the water. Major fish kills and significant water-life deterioration have resulted from chlorinated dis- charges. Such discharges, even at extremely low levels, have been shown to harm fish and other water organisms in various stages of their life cycle. Sewage chlorination creates compounds which are potentially carcinogenic, but only a small amount of these compounds are found in drinking water. CHLORINATED DISCHARGES ARE TOXIC ------------------------ TO-THE AQUATIC ENVIRONMENT ------------------- --- Many scientific studies have demonstrated the toxic effects of chlorinated discharges. Significant fish kills have been caused by such discharges. Although fish gener- ally try to avoid chlorinated discharges, major fish kills have been directly traced to chlorinated sewage, and chlorine residuals may have been a principal factor in other fish kills ascribed to sewage effluent. Fish kills have also been caused by chlorine discharges from powerplants. Very low levels of chlorine in sewage discharges harm fish repro- duction and growth. Chlorinated discharges have played a major role in the deterioration of aquatic life in various bodies of water in the United States as illustrated by the following examples: --Major fish kills occurred in the lower James River in Virginia in 1973 and 1974. The Virginia Institute of Marine Science investigated the kills and attributed them to chlorine residuals from sewage treatment plants. Overall, 5 to 10 million fish probably died over a 3-week period in 1973. The species affected included bluefish, striped bass, weakfish, and menhaden. Following a reduction in the levels of re- sidual chlorine in the sewage effluent, dead fish counts dropped from thousands to tens within 2 days. A similar experience occurred the following year. In addition, when the chlorine was cut back, the oyster season was unusually successful while other estuaries entering the Chesapeake Bay were no more productive than usual. --A major fish kill due to chlorine residuals from sew- age treatment plants was noted by the California Fish and Game Department in 1972 in the Sacramento River 3 of California. Estimated losses of eggs, larvae, and fingerlings were in the millions for salmon, and in the billions for striped bass and shad. Sturgeon and catfish were also killed. The California Fish and Game Department reported that the fish lost would have been a significant portion of the State's fish- ery resources. For king salmon alone, the Fish and Game Department estimated the loss at $1,123,200. --In studies of San Francisco Bay published in 1972 and 1974 (made because of periodic fish kills and deteri- oration of the fisheries there), sanitary engineering researchers at the University of California at Berkeley suggested that chlorine in wastewaters may be the largest single source of toxicity entering San Francisco Bay. The researchers concluded that chlorinated sew- age, even after secondary treatment, is harmful to aquatic life. The tests demonstrated impairment to oysters exposed near plant outfalls; and in laboratory studies, baby clams and oysters experienced 50-percent mortality at chlorine residuals less than 5 parts per billion (ppb). Chlorine discharges above 1,000 ppb are frequently found in sewage discharges. --In some years pollution from municipal waste was the leading cause of fish kills in the United States. Five fish kills in 1974-75 were specifically ascribed to chlorine in domestic sewage. However, many reports of fish kills from municipal operations have indicated that suffocation from low dissolved oxygen caused by sewage was the immediate cause of death. Studies of research literature done by an Assistant Director of EPA's Duluth, Minnesota, Environmental Research Lab- oratory cited two studies published in 1975 which suggested that, because chlorine interferes with a fish"s ability to respire, many fish may have died from residual chlorine or the combined effects of sew- age and residual chlorine. --A 1974 progress report prepared by fisheries research- ers at Oregon State University reported that coho salmon exposed to only 20 ppb of residual chlorine had significantly impaired growth. The illustration on page 6 demonstrates the effects of various levels of residual chlorine on the growth of continuously ex- posed coho salmon. --Chlorine has been found to affect the environment in very subtle ways. Several studies, including four done by Michigan Department of Natural Resources re- searchers in 1971, reported long river reaches down- stream rendered uninhabitable to many fish due to 4 chlorine residuals in sewage effluents. Aquatic organisms in the food chain other than fish may be killed or harmed. Tests have shown that the high- est total residual chlorine concentration having no measurable chronic adverse effect on an important fish food organism was 2 to 4 ppb. A level of 6 ppb is roughly equivalent to a quart of laundry bleach in 2 million gallons of water. Chlorine also in- terferes with the anaerobic conditions essential to the normal processes in a tidal salt marsh, or swamp, and with the reproduction of some aquatic animals. Chlorinated organics may interfere with chemical com- munications systems (for example, in the sensing which some fish species use for homing to breeding areas). ONLY -em--- A SMALL AMOUNT OF SUSPECTED ----1_ CARCINOGENS ----m------.-L- IN DRINKING WATER --- ARE A RESULT ------ OF SEWAGE -a----- CHLORINATION Sewage chlorination results in a large number of chlo- r inated organics. In a March 1976 task force report, EPA reported that some of these organics are suspected causes of cancer. One such organic--chloroform--was banned in foods and in medicinal and cosmetic products in July 1976 by the Food and Drug Administration. In a July 1975 report to the Congress, EPA reported that chloroform has been found widely dispersed in U.S. drinking waters. A study l/ pre- pared for EPA reported that almost all of the chloroform found in drinking water appears to have been formed during the process of drinking water chlorination, rather than dur- ing the process of sewage chlorination. Many organics formed in sewage chlorination have not yet been identified, and the effects of most of those which have been identified are unknown. Some scientists are con- cerned with the unknown effects of these organics considered either individually or collectively. Although sewage chlo- rination is a source of chlorinated organics in streams, fish, and shellfish, the major source is industrial dis- charges, especially from pulp and paper plants. Runoff of agricultural chemicals (for example, pesticides and herbi- cides) may also be a source of chlorinated organics. L/"Formation of Halogenated Organics by Chlorination of Water Supplies," prepared by Harvard University and distributed by the National Technical Information Service of the U.S. Department of Commerce. 5 EFFECT OF RESIDUAL CHLORINE ON GROWTH OF COHO SALMON COURTESY: OAK CREEK LABORATORY OF BIOLOGY. DEPARTMENT OF FISHERIES AND WILDLIFE, OREGON STATE UNIVERSITY CHAPTER 3 -------- UNNECESSARY SEWAGE CHLORINATION --------1------1-----w-v The value of widespread sewage chlorination appears to be questionable because: --The few incidents of disease transmitted through water in the United States are generally not serious and are generally transmitted through inadequately treated drinking water. --The effectiveness of sewage chlorination varies, de- pending on the specific waterborne disease agent in- volved. --Sewage disinfection is not extensively practiced in other industrialized countries with public health ex- periences similar to those in the United States. --Widespread sewage disinfection is a recent phenomenon in this country, with little accompanying improvement in public health. --Epidemiological studies attempting to relate bacterial levels in swimming waters with levels of illness have been inconclusive. Specifically, sewage disinfection is usually not needed to protect --swimmable waters in cold weather periods, --waters rarely used for swimming, or --drinking water. In addition, chlorine production is energy intensive and a substantial reduction in its use would save a signif- icant amount of energy. EPA could do more to discourage un- necessary sewage chlorination. Its virtual mandating of universal sewage disinfection in 1973 established year-round universal chlorination of sewage as a norm of water quality protection and, in many instances, resulted in chlorination of sewage which state officials believe was not necessary. Although EPA removed the year-round universal need for sewage chlorination, this action will probably not significantly reduce unnecessary chlorination since many States plan to continue year-round chlorination. In addition, EPA water quality bacterial criteria for swimming waters may effec- tively reinstate universal, year-round sewage chlorination 7 when compliance with the 1983 interim goal of swimmable waters is required. VALUE OF WIDESPREAD SEWAGE CHLORINATION PBR-~fS~~S~-~~~T~B~-~~-~~~~~~~~~~--- --------------------y___________ Diseases with known causes, for which the Center for Disease Control, U.S. Public Health Service, has reported waterborne incidents, include salmonellosis, shigellosis, typhoid, cholera, hepatitis-A, amoebic dysentery, and giardiasis. The most common of these diseases, salmonellosis and shigellosis, are both characterized by abdominal pain, diarrhea, nausea, and vomiting. Two other bacterial dis- eases, cholera and typhoid, are more serious, but the United States averages less than 430 cases and 8 deaths per year. from typhoid fever (1965-73) and has had only 1 indigenous case of cholera in the last 65 years. Most water borne illnesses are directly traced to inade- quately disinfected drinking water, not sewage water, al- though the contamination frequently originates from sewage. In addition to inadequately treated drinking water, in- gestion of raw or partially cooked shellfish (presumably from contaminated waters) may play a significant role in trans- mission of viral hepatitis. Due to the paucity of evidence., the role of swimming in sewage-polluted water in the trans- mission of illness has not been conclusively defined. The effectiveness of sewage chlorination against var- ious organisms that cause waterborne diseases varies, de- pending on the disease organism involved. Sewage chlorina- tion is aimed particularly at bacteria and has been thought to be generally effective in this regard. Levels of bac- teria, however, may actually establish their original numbers through regrowth. L/ Viruses are generally more resistant than bacteria to chlorination, and they require a much heavier dosage and longer contact time. Secondary wastewater treatment fol- lowed by chlorination, as generally practiced, will not re- duce virus concentrations effectively, particularly in the case of the more resistant viruses such as those which cause hepatitis. Only where plants provide tertiary treatment L/Report No. 76-17, "Wastewater Disinfection: The Case Against Chlorination," published in June 1976 by the De- partment of Research and Development of the Metropolitan Sanitary District of Greater Chicago. 8 (for example, high levels of filtration) to produce very clear affluent can they achieve effective virus inactiva- tion. A relatively small number of sewage treatment plants in the United States provide such tertiary treatment. Foreign disinfection ------a---- practices The United States appears to be unique in its exten- sive year-round chlorination of sewage. Representatives of other countries with public health experience similar to ours generally told us that sewage disinfection is only rarely practiced in their countries. --Officials from Scandinavian countries l/ said that sewage disinfection is rare in their countries'and cited the harmful environmental effects of chlorine as a reason. The Secretary of the Embassy of Norway said that c'llorine was not used for disinfection be- cause of the possible poisonous effects on the re- ceiving water body. The Science Attache of the Em- bassy of Sweden said that chlorine was not used for sewage disinfection and that it was regarded as a harmful substance not to be indiscriminately dumped into the nation's waters. --The Science Attache of the Embassy of Great Britain said that sewage disinfection is rarely practiced in Great Britain and that it is considered undesirable. He said that a study found no beneficial effects on the Thames River from chlorinating sewage discharges. -The Science Attache of the West German Embassy said that sewage disinfection is practiced very rarely in West Germany and that it is considered unnecessary. She said chlorination is only used in connection with some advanced waste treatment processes in which chlo- rine is used for its ability to oxidize certain sub- stances, not necessarily for its disinfectant proper- ties. --The Scientific Attache of the Embassy of France stated that there is no general requirement in France for sewage disinfection. Technicians may require disin- fection in particular instances. Most such instances involve the protection of (1) drinking water sources, (2) seaside resorts, and (3) shellfish. A French spe- cialist in sanitary engineering told us that less than ------ l/Denmark, Norway, and Sweden. 9 2 percent of the sewage in France is chlorinated and that requirements are imposed on a case-by-case basis, generally only for the 3 summer months. --The Science Attache of the Embassy of the Netherlands told us that sewage chlorination is practiced only at plants that discharge near oyster beds and, during the summer, at several municipal sewage treatment plants that discharge near public bathing beaches. * Public health statistics shown on page 11 indicate that death rates for bacterial and viral gastrointestinal diseases are similar in these countries to rates in the United States. It should be noted that while the Swedish rate for enteritis and * other diarrhea1 diseases is one-sixth that of the United States, the Norwegian rate is almost twice the rate for this country. Sewage disinfection in the United States Only recently has wastewater disinfection in the United States become widespread. Until 1945 most sewage treatment plants practicing disinfection belonged to the U.S. Armed Forces. In 1958 about 30 percent of all wastewater treatment facilities were equipped for chlorination; these chlorinating facilities served about 38 million people. In 1968, 41 per- cent of all municipal wastewater plants in the United States were using chlorine for disinfection. In mid-1976 our sur- vey of nearly 400 sewage treatment plants showed that 74 percent of those responding used chlorine for disinfection. The Executive Secretary of the Water Pollution Control Feder- ation explained that municipalities probably were slow in im- plementing disinfection because of the uncertain health ben- efits of disinfecting treated wastes and the cost of chlorine. Also, the Chief of EPA's Municipal Technology Branch stated that States have had differing views on the need for disin- fection. The Assistant Director of the Bacterial Diseases Division of the Center for Disease Control told us that there is no c evidence that the substantial increase in sewage chlorination over the last 5 to 10 years has resulted in any reduction in waterborne diseases. The Center for Disease Control has taken the position that disinfection of sewage produces few public c health benefits. The GAO medical consultant contacted a variety of ex- perts in epidemiology and sanitary engineering. He found that there is no unanimity of opinion concerning the desir- ability of discontinuing the chlorination of sewage efflu- ents. On the one hand, the medical epidemiologists we con- tacted tended to feel that sewage chlorination is wasteful 10 and does not really contribute to human health and well being. On the other hand, public health engineers favor continuing chlorination to ensure reasonably high water qual- ity standards for recreational waters. In our opinion, epidemiological studies attempting to relate bacterial levels in swimming waters with levels of illness have been inconclusive. (For a review of the prin- cipal studies, see app. I.) In fact, a 1952 study by the U.S. Public Health Service (see p. 38), suggested that swim- ming in a polluted river is no more hazardous to health than swimming in a chlorinated swimming pool. The Assistant Director of the Bacterial Diseases Divi- sion, Center for Disease Control, told us that the risk of a swimmer incurring a bacterial gastrointestinal infection from swimming is small. According to a Center for Disease Control memorandum dated August 20, 1975, and data from volunteer typhoid fever experiments i/, a large number of infectious organisms must generally be ingested to cause a typhoid or other salmonellosis infection in a healthy adult. The Assist- ant Director told us that the average number of typhoid and other salmonella bacteria occurring in the amount of sewage water normally ingested while swimming is only a fraction of the infectious dose (in the absence of raw sewage or fecal particles) and is highly unlikely to cause disease. Although the number of infectious organisms that would have to be in- gested to cause one form of shigellosis is quite low, only one outbreak of swimming-related shigellosis (possibly from raw sewage) had been documented as of March 1975. 2/ CHLORINATION OF SEWAGE IS NOT NEEDED TO PROTECT SWIMMERS DURING COLD WEATHER MONTHS We could find no justification for chlorinating munici- pal waste discharges during the nonswimming season (with the exception of shellfish-harvesting areas). Numerous experts told us that chlorination is usually unnecessary during cold winter months when human contact and the chance of disease transmission from undisinfected sewage is negligible. --The Assistant Director of the Bacterial Disease Divi- sion, Center for Disease Control, said that there is . L/A section entitled, "A Probabilistic Model of Bathing Beach Safety," in the book The Science of the Total Environment, 1975. z/From a Center for Disease Control report dated March 18, 1975, on the transmission of shigellosis by swimming on a portion of the Mississippi River in 1974. 13 no public health justification for sewage disinfection during the period of the year when swimming is not likely . Although officials of two States justified chlorination during cold winter months on grounds that it is necessary to protect hunters, fishermen, and hikers, the Center for Disease Control official told us that there is little public health evidence to support chlorinating to protect fishermen and hunters who may come into casual primary contact with waters receiving unchlorinated sewage. --A British sanitary engineer teaching at the University of California told us that chlorinating sewage in cold weather to protect fishermen from primary contact is inappropriate. --EPA scientists and foreign experts said that, in the absence of shellfish harvesting areas, other nations with similar levels of mortality from gastrointestinal diseases practice sewage chlorination near bathing beaches, if at all, only in the summer months. --EPA research scientists studying sewage disinfection said that the need for universal year-round sewage disinfection has not been clearly demonstrated. In addition, in March 1976, an EPA task force report on wastewater disinfection recommended that disinfec- tion not be required in cold weather when there is no swimming. The report cited favorably the example of communities, such as New York City, which chlorinate only during the swimming season. EPA has reported in the Federal Register that requiring a minimum level of disinfection for all wastewater is of question- able benefit when the possibility of human contact with the receiving water is remote. Even in the absence of shellfish-harvesting areas, we found that many cold weather States, including Alaska, Michigan, and Minnesota, require continuous year-round sewage chlo- rination, with no reductions permitted during cold-weather months. CHLORINATION IS NOT NEEDED FOR SEWAGE DmaS INTO WATERS RARELY USED FOR SWIMMING - Some lakes and streams are unswimmable for a variety of reasons and chlorinating discharges into these waters would still not make them swimmable. A public health expert from the Center for Disease Control said there is no need to chlorinate discharges into unswimmable waters since public health is not jeopardized. 14 Officials from several States told us that they had many lakes and streams that are never used for swimming or for irrigation and therefore they believed disinfection was prob- ably unnecessary. One Indiana State official estimated that only 50 of Indiana's estimated 300 municipal sewage treatment plants (17 percent) discharge sewage to waters used for di- rect water recreation, yet 90 percent of these plants dis- infect wastes. An Illinois State official estimated that 80 percent of all municipal sewage treatment plants in Illinois discharge to streams not used for swimming or other water recreation, but 60 percent disinfect wastes. A New York State official estimated that only 75 of New York's 500 mu- nicipal sewage treatment plants--l5 percent--discharge to waters used for swimming, but 90 percent of the plants dis- infect wastes. According to State officials, people avoid direct water recreation in some lakes and streams for the following rea- sons: --Man-made pollution makes water aesthetically unswim- mable. (For example, floating debris, algae blooms, or high proportions of sewage discourage swimming in the Spokane River and Long Lake in Washington State, the Trinity River in Texas, and streams in Indiana.) --Non-point source pollution makes water look unpleas- ant for swimming. (For example, soil erosion reach- ing levels of 20,000 tons a year makes the Palouse River in Washington State unattractive for swimmers.) --Heavy commercial navigation prevents safe water rec- reation. (For example, the Chicago barge canal and the Hudson River in New York are unswimmable for this reason.) --Stream water conditions are such that they do not lend themselves for water recreation. (For example, many streams in Illinois, Indiana, and Texas are too narrow or shallow for swimming, and in New York many are unswimmable for this and other reasons, namely, water temperature and speed of flow.) At least one unit of local government has attempted to prevent unnecessary chlorination where water (in this case, the Chicago Sanitary and Ship Canal) is not used for primary recreation. In February 1976 the Metropolitan Sanitary Dis- trict of Greater Chicago petitioned the Illinois Pollution Control Board to grant a sewage treatment plant a variance to the statewide disinfection requirement. Evidence cited by the sanitary district to support its petition included 15 --the board rules and regulations which designate that the Chicago Ship Canal is not intended for swimming; --heavy commercial use (2 million tons of freight carried by ships and barges each month) and its nar- row channel, which make recreational activities vir- tually impossible; --a lack of historical evidence to suggest that the canal is used by the citizens for recreational pur- poses; and --significant chlorination costs in excess of $1 million a year) without public health benefits. In November 1976 the director of research and develop- ment for the sanitary district told us that the State board had denied the variance. The district now plans to request a change in the statewide disinfection requirement. Most States, however, do not adjust requirements for disinfection of wastewater because of the use of the receiv- ing stream (if any) or the proximity of the wastewater dis- charge point to the location of water use. CHLORINATION OF TREATED WASTEWATER IS -----------v----1------------- USUALLY NOT NEEDED AS A BACKUP TO --------u_---------__I____ DRINKING WATER DISINFECTION ------l_-------------w Sewage chlorination has been supported on grounds that it is necessary to protect (1) raw drinking water supplies downstream from sewage outfalls, (2) water from private wells located near streams and rivers, and (3) drinking water for cattle which use streams and rivers as a source of water. We believe, however, that there is an insufficient public health basis to warrant widespread chlorination of treated sewage for any of these reasons. In its July 1976 change in disinfection requirements, EPA encouraged continued sewage disinfection to protect pu.b- lit water supplies. The Center for Disease Control, however, has taken the position that disinfection of sewage as a backup to disinfection of drinking water has very little public health basis. The Assistant Director of the Bacterial Dis- eases Division of the Center for Disease Control made the following comments concerning protection of drinking water supplies: --Sewage disinfection is generally not useful as a means of protecting drinking water, since water sup- plies can be much more appropriately and economically 16 disinfected during the course of drinking water treatment. Sewage disinfection as a preparation for drinking water treatment is usually not cost-benefi- cial because only a small percentage of diluted sewage water is generally reused in drinking water. --Available evidence suggests that the drinking water in areas of the United States where sewage disinfec- tion still is not widely practiced carries no more risk of disease transmission than in other areas. --Sewage disinfection does not provide an effective backup in cases of drinking water treatment failure. EPA research scientists also discounted the importance of chlorinating sewage as a safety factor in case of a drink- ing water chlorination breakdown. According to a professor of sanitary engineering at the Johns Hopkins University, the question as to whether sewage should be chlorinated should be determined on an individual basis taking into consider- ation proximity of the sewage outfall to the water intake, the rapidity of water movement, and the amount of sewage being deposited. Several public health officials expressed concern that sewage chlorination was necessary to protect owners of wells close to rivers that receive sewage discharges. According to EPA officials, sanitary practice requires that wastewater be disinfected as an added level of protection from source con- tamination which might be transmitted to these wells. De- pending on the quality of the raw well water, chlorination or other treatment to provide a potable supply may be needed. However, sewage seepage into drinking wells is unlikely be- cause the normal hydraulic flow would be in the opposite di- rection (that is, toward the river). The Assistant Director of the Bacterial Diseases Divison of the Center for Disease Control 'said that there have been a few cases in which a well near a river had been polluted by river water because of unusual conditions. However, he said that even in those few cases, the answer is not to attempt to make the raw river water drinkable by disinfecting sewage. Instead, he said it would be much safer and cost-effective for individual well owners to chlorinate their own well water or, where feasible, jointly to build a (drinking) water treatment plant. Several public health officials expressed a concern with transmission of diseases in human sewage to cattle who drink from streams receiving such sewage. Two professors of veter- inary medicine at Washington State University told us that such concerns were invalid because cattle generally are not subject to the human diseases normally transmitted through sewage. In addition, they said that there is no scientific 17 evidence tracing animal disease to sewage in river water. Although cattle are subject to tuberculosis and worm infesta- tions, normal sewage chlorination is not effective against the carriers of these diseases. l/ EPA COULD DO MORE TO DISCOURAGE ------------m----m---------- ---------------------- CHLORINATION UNNECESSARY An EPA report, "Restoring the Willamette River: costs and Impacts on Water Quality Control," published in Septem- ber 1976, concluded that post chlorination of wastewaters requires large amounts of energy and should be better regu- lated. The report recommended, among other things, that '* * * Chlorine production is highly energy inten- sive and a substantial reduction in its use would yield significant energy savings. This fact, along with chlorine's counter-productive instream biological effects and possible carcinogenicity, clearly shows the need for further research. This work should include evaluating the need for bac- terial reduction as well as evaluating, alternative means by which this reduction might occur." For the Willamette River Basin, the study reported that the energy needed to produce the chlorine used for dis- infection of municipal wastewaters was equal to between 40 and 50 percent of the electricity used to operate the treat- ment plants. In August 1973, although EPA was aware of the potential for harmful environmental effects from chlorinated dis- charges and although we believe the public health need for it was tenuous, EPA virtually mandated year-round universal sewage chlorination. It did so by defining secondary treat- ment to include a bacterial limitation based on levels attain- able in most facilities only by disinfection. Chlorine (in one form or another) was virtually the only sewage disinfec- tant available to meet these bacterial standards. In 1973 an estimated 2,000 tons of chlorine was used for wastewater treatment in the Willamette River Basin. The total annual expenditure for chlorine in the 1973-74 period was $260,000. --------- l/From an article entitled, "Compatability of Wastewater Dis- infection by Chlorination,"' in the September 1961 issue of the ------ Journal of the---mm Water Pollution -------------_l- Control. Federation. 18 In establishing bacterial standards, EPA stated that it considered disinfection to be an important element of second- ary treatment, which is necessary for protection of the pub- lic health. In our opinion, the effect of this action was to establish sewage disinfection as the norm in the protec- tion of national water quality. The EPA action, according to State officials, resulted in much unnecessary chlorina- tion, including that of discharges into dry stream beds. On July 26, 1976, approximately 3 years after establish- ing the requirement, EPA removed the bacterial standard from its definition of secondary treatment. Now State and local water quality standards are used to determine disinfection practices. State and local water quality standards will use EPA's water quality criteria as a basis for regulating a plant's effluent. This procedure allows the States to stop some chlorination if they consider it unnecessary, for example, discharges into dry stream beds and discharges dur- ing cold weather. The Chief of EPA's Municipal Technology Sranch stated that EPA intended to have the States determine site specific requirements based on water use. EPA's change in secondary treatment standards, however, will probably have only a lim- ited impact in reducing unnecessary chlorination. Our sur- vey of State disinfection practices and policies showed that 25 States did not plan to reduce chlorination requirements even with EPA's change. In addition, EPA's water quality criteria dated July 26, 1976, includes the same low bacterial levels (200 fecal coli- form per 100 ml.) for swimmable waters. No consideration was given to limiting the bacteria criteria for swimming to certain times of the year. Since Public Law 92-500 estab- lishes as a national goal that, wherever attainable, all waters be swimmable, inclusion of a bacterial limitation in water quality criteria for swimming waters will essentially reestablish universal year-round chlorination of sewage. An EPA official in the Criteria and Standards Division stated that the current water quality standards, including bacterial standards, do not allow for seasonal variation, and this might have to be changed. EPA's criteria for bacteria in swimmable waters do not have a strong scientific basis. The level of 200 fecal coli- form per 100 ml. as a safe level for swimming water was formulated from a 1952 study which reported that swimmers in a heavily polluted river experienced somewhat more nausea, cramps# and diarrhea than statistically expected when com- pared with swimmers in a chlorinated swimming pool. This study found no relationship, however, between bacterial 19 levels and disease incidence. (See p. 38.) After reviewing this and other studies, the National Academy of Sciences- National Academy of Engineering Committee on Water Quality Criteria, in 1972, refused to establish any standards for microbial organisms in swimming water because of the pau- city of evidence. CONCLUSIONS ---------mm There are many reasons for questioning the value of sewage chlorination as practiced in the United States today. There are differing views among experts concerning the need for disinfection, but it appears that widespread year-round sewage chlorination is questionable. Certainly, in the absence of shellfish harvesting or unrestricted irrigation, disinfection of treated wastes is usually not needed to pro- tect drinking water supplies since the water is purified in water treatment plants. Nor is it usually needed to protect swimming waters in cold weather or to protect waters rarely used for swimming. Chlorine is energy intensive and a re- duction in its use would save substantial amounts of energy. EPA could do more to discourage unnecessary disinfec- tion. Because EPA includes a bacterial limit in its water quality criteria for swimming, many States plan to continue to require universal year-round sewage disinfection. RECOMMENDATIONS TO THE ADMINISTRATOR OF EPA --------------------l______________l_ We recommend that the Administrator EPA: --Revise the Agency's water quality criteria regarding the bacteria standard for swimming waters to recog- nize seasonal variations and that he specifically de- lineate those circumstances in which sewage chlorina- tion is or is not needed to protect the public health. RECOMMENDATION TO --------e-e THE CONGRESS ---I_-- To reduce unnecessary chlorination of sewage, the Con; gress should amend the Federal Water Pollution Control Act of 1972 to permit exceptions from the national goal of swim- mable waters to recognize those situations in which waters are determined to be unswimmable because of other factors, such as heavy barge traffic, cold seasons of the year, and general appearance. 20 CHAPTER 4 NEED TO PREVENT HARMFUL LEVELS OF RESIDUAL CHLORINE IN DISINFECTED SEWAGE AND OTHER EFFLUENTS Although sewage disinfection appears to be needed only in certain specific situations, such as reducing disease transmission through raw shellfish and sewage used for un- restricted irrigation, sewage disinfection is widely practiced. Where sewage chlorination is practiced, levels of residual chlorine are far in excess of levels found safe to the aquatic environment, and frequently, because of imprecise testing procedures, the levels being reported grossly understate the actual levels being discharged. Public Law 92-500 calls for control of toxic pollutants, and chlorine is a toxic pollutant as defined by the act; how- ever, EPA has not listed residual chlorine as a toxic pollut- ant requiring standards for its discharge. Other groups, including both the U.S. National Academy of Sciences and the European Commission on Inland Fisheries, have strongly recom- mended control of chlorine residuals. EPA has taken some action, though inadequate to protect the aquatic environment, to limit chlorine residuals in powerplant discharges. In addition, several States have taken actions to limit chlorine discharges. Methods of removing most of the toxicity of chlorine residuals (dechlorinating) are available, though costly. Chlorine toxicity in receiving waters can be avoided by using other methods of disinfection. However, the prin- cipal alternatives, while appropriate under limited circum- stances, all have disadvantages which make it unlikely that any of them will generally replace chlorination in the near future as the principal means of disinfecting wastewater. These alternatives include land treatment, lagoons, and disinfection with ozone, ultraviolet radiation, and bromine chloride. For further details on these alternatives, see appendix II. Improving the efficiency of the disinfection process reduces both dosages and residuals and thus minimizes the toxic effects of chlorine on receiving waters and the dis- charge of potentially carcinogenic compounds. Improved effi- ciency can be achieved by improving the design of chlorina- tion facilities, selecting more effective equipment for the chlorination process, and improv,ing the quality of the ef- fluent. 21 Progress has been slow, however, by the States and EPA in improving the disinfection process in existing plants or in ensuring that new construction provides for efficient and effective chlorination. SEWAGE CHLORINATION MAY BE NEEDED TO PROTECT SHELLFISH-HARVESTING AREAS AND WHEN SEWAGE IS USED FOR UNRESTRICTED IRRIGATION The chlorination of sewage may be of significant value in reducing disease transmission through consumption of raw shell- fish grown in fecally contaminated water. In the process of feeding, shellfish, such as oysters and clams, filter and re- tain harmful bacteria and viruses; in doing soI they concen- trate these bacterial and viral pathogens in their flesh. Shellfish grow in coastal waters, and nearly all shellfish waters are subject to some degree of pollution. In the past, when typhoid fever was more prevalent, consumption of raw shellfish was associated with the transmission of that disease. The last such case in the United States occurred in 1939. In the United States, no outbreaks of salmonellosis or shigellosis have been traced to the consumption of raw shell- fish in the last 10 years. Chlorination of sewage discharges into shellfish-harvesting areas may therefore have helped con- trol transmission of bacterial diseases in shellfish. Infectious hepatitis continues to be associated with in- gestion of raw or partially cooked shellfish. The effective- ness of sewage chlorination in killing the hepatitis virus is not known with certainty. The virus that is presumed to cause hepatitis has never been isolated, Viruses are generally more resistant than bacteria to chlorination, and the hepatitis virus appears to be among the more resistant viruses. Fruits and vegetables growing in infected soil can be- come contaminated with pathogenic bacteria, and these bacteria may survive for periods from a few days to several weeks or more in the soil. However, pathogens are seldom detected on farm produce unless the plant samples are grossly contaminated with sewage or have fecal particles clinging to them. The National Academy of Sciences-National Academy of Engi- neering Committee on Water Quality Criteria, after reviewing the dangers of parasitic worms and other organisms not effec- tively destroyed by sewage treatment or chlorination, stated in its 1972 Water Quality Criteria that it is good practice to restrict irrigation with sewage water to crops that are adequately processed before sale and to crops that are not used for human consumption. For unrestricted irrigation, for example, on fresh fruits and vegetables, the 1972 Water 22 Quality Criteria indicated that wastewater should receive primary and secondary treatment and adequate chlorination. CHLORINE RESIDUALS IN MANY LOCATIONS ARE TOO HIGH FOR SAFE DISCHARGE Very low concentrations of chlorine residuals are toxic to aquatic life. Based on scientific research, experts--both foreign and American-- have developed the following residual chlorine standards to safeguard aquatic life: --The European Inland Fisheries Advisory Commission has recommended, as criteria to protect European fresh- water fish species, residual chlorine ranging from 4 to 121 ppb, depending on temperature and acidity/ alkalinity of the water. --Various U.S. scientists have developed residual chlorine criteria for freshwater aquatic life. These criteria run from 2 to 20 ppb for continuous discharge and from 40 to 200 ppb for intermittent discharge. --The National Academy of Sciences-National Academy of Engineering Committee on Water Quality in its fresh- water aquatic life criteria recommended a maximum residual chlorine concentration of 3 ppb for contin- uous discharge and 50 ppb for intermittent chlorination of up to 30 minutes in any 24-hour period. --Fifteen States have established maximum residual chlorine effluent standards for at least some waste- water discharges. Some States and local areas have established maximum residual standards for all chlori- nated discharges. For example, in the area of San Francisco Bay, all sewage dischargers are required to reduce chlorine residuals virtually to zero because of the toxic effects of chlorine, according to an official of the regional water quality control board. During our review, however, we noted that wastewater effluent often contains residual concentrations many times higher than the levels mentioned above that are considered safe. For example: --Research scientists have observed total residual chlorine values of 5,170 ppb in treatment plant 23 effluent in central Illinois l/, over 10,000 ppb in southern Wisconsin A/, and up-to 7,000 ppb in Cali- fornia. 2/ --Ten waste treatment plants in the Tualatin River Basin in Oregon reported annual average chlorine residuals in treatment effluents ranging from 1,300 to 3,400 ppb, with most of the values around 2,000 wb. Peak chlorine residuals during the year were much higher. --In our national survey of sewage plant disinfection practices, we found that over 30 percent reported an average chlorine residual for 1975 at or above 1,000 ppb in their effluents. About 27 percent reported a peak measurement for the year between 2,000 and 5,000 ppb, with about 8 percent reporting even higher peak measurements. In addition to being excessive, the reported residuals frequently understated the actual level of chlorine residual in the discharge. There are two principal causes of such understatement: (1) widespread use of an inadequate measur- ing method and (2) not sampling when chlorine residuals are likely to be high. Inadequate measuring method The most common means of measuring residual chlorine in wastewater is the orthotolidine method. Using this method, orthotolidine is added to a sample and the resulting color is compared to a color standard chart. This method is sub- ject to interferences, and it tends to understate the pres- ence of chlorine. Orthotolidine measurements generally re- port about one-half of the actual amount of chlorine 3/, L/From a paper by W. A. Brungs entitled, "Effects of Waste- t water Chlorination on Freshwater Aquatic Life" presented, at the annual meeting of the Water Pollution Control Fed- eration in October 1975. . /Mentioned in a November 1, 1974, transcript of proceedings of the California Regional Water Quality Control Board. g/From an article by C. M. Robson, B. S. Hyatt, Jr., and S. K. Banerji entitled, "We Must Improve Chlorination Design," in the September 1975 issue of Water and Wastes Engineering. 24 and they have reported as low as one-sixth L/ of the residual chlorine measured by more sophisticated methods. In our survey of sewage treatment plants, however, we found that 76 percent were still using the orthotolidine method. Inadequate testing of chlorine residuals Although chlorine residuals are monitored regularly by most treatment plants using chlorine, many plants in our survey reported that they did not test during the early morning hours (prior to 7 a.m.) when, we were told, condi- tions of low flow and demand and, thus, high residuals tend to predominate. The differences of chlorine residuals in tests taken at times of low flow and tests taken during periods of high flow can be substantial. An authority on wastewater disinfection said that in early morning hours (e.g., 5 a.m.) chlorine residuals from small plants may run as high as 22,000 ppb. THOUGH A TOXIC POLLUTANT, CHLORINE RESIDUALS ARE LARGELY UNCONTROLLED Public Law 92-500 established a national policy against discharge of toxic pollutants in poisonous'amounts. Sec- tion 502 of the act defines "toxic pollutant" as a pollutant which will cause death, disease, or physiological malfunc- tions after assimilation into any organism (human, fish, etc.). As demonstrated in chapter 2, residual chlorine fits this definition and it is being discharged in excessive amounts. Section 307 of the act requires the Administrator of EPA to publish a list of toxic pollutants and to set effluent standards for them. In June 1976 EPA published a list of 65 toxic substances proposed for control, but final effluent standards have not been established for any of these sub- stances. The Chief of EPA's Criteria Branch explained that elemental chlorine was not included in the list of 65 sub- stances because it does not persist in the aquatic environ- ment. Scientists are concerned, however, that when chlorine is mixed with sewage or cooling waters it may form toxic com- pounds such as chloroform. L/From a paper by Thomas E. Harr, entitled, "Residual Chlo- rine in Wastewater Effluents Resulting from Disinfection," -.Technical Paper No. 38, prepared by the Environmental Qual- ity Research Unit of the New York State Department of Environmental Conservation. 25 Research results presented at the Conference on the Environmental Impact of Water Chlorination in October 1975, indicated that five of the EPA listed toxic substances can be created by mixing chlorine with sewage or powerplant cooling waters. Two of these substances were included on an EPA priority list of toxic substances for which "no effective threshold dose can yet be established." The National Academy of Sciences classified substances as "highly toxic" to aquatic life when a concentration of 10,000 ppb will kill half a test population within 96 hours. The extreme toxicity of chlorine is best illustrated, there- fore, by research which found that a level of 10 ppb killed 67 percent of a population of brook trout in 96 hours. &/ The harmful effects of chlorine discharges on salmon, menhaden, and shrimp have already been illustrated earlier in this report. EPA has stated that effects on economically important species, such as trout, salmon, menhaden, and shrimp, are properly considered in the development of a pro- tective criterion level for toxic pollutants. Others also contend that chlorine discharges are a serious problem and that chlorine residuals should be con- trolled: --The Assistant Director for Water Quality Criteria at EPA's Environmental Research Laboratory, Duluth, Minnesota, said that one might hypothesize that chlorine as a pesticide should be registered just like other pesticides. --Water Quality Criteria-1972, a report prepared by the National Academy of Sciences-National Academy of Engi- neering Committee on Water Quality Criteria, under EPA contract and approved by EPA for publication, listed chlorine among toxic substances. The Chief of EPA's Standards and Criteria Development Branch, Water Supply Division, said the feeling at EPA was that to classify chlorine as a pollutant would be "illogi- cal" so long as it is still needed as a disinfectant. The Assistant Director of EPA's Effluent Guidelines Division said that he does not believe chlorine is toxic enough to be so classified under Public Law 92-500. He told us that L/From an article by William A. Brungs entitled, "Effects of Residual Chlorine on Aquatic Life" in the October 1973 issue of the Journal of the Water Pollution Control Federation. 26 EPA does not plan to control chlorine discharges from sewage plants or other industries. While EPA sets no limits on residual chlorine in ef- fluents from sewage treatment plants and other industrial effluents, in October 1974 it limited chlorine discharges in powerplant effluents. The maximum limit was set at 500 ppb of free residual chlorine, and the average limit was 200 ppb of free residual chlorine. In setting its standard, EPA noted the large quantities of chlorine added annually to waters from powerplant discharges. In contrast to the na- tional standard, an EPA region III official told us that re- gion III has set a maximum 200 ppb total of residual chlo- rine (free and combined chlorine) for powerplants in its re- gion. In contrast, EPA has not set a maximum standard for the levels of chlorine in discharges from sewage treatment plants, which collectively use an estimated 200,000 tons L/, about twice as much chlorine as powerplants. 2/ When EPA proposed the powerplant standards, comments were received from powerplant officials that sewage treatment plants were not similarly controlled in their chlorine discharges. MOST TOXIC CHLORINE RESIDUALS CAN BE REMOVED Means are available to remove most chlorine residuals and the hazards associated with them. The addition of sul- fur dioxide to wastewater is the most common dechlorination method. It increases the cost of chlorination by an esti- mated 20 to 30 percent. Addition of sulfur dioxide may reduce the level of dissolved oxygen, but an EPA Research Microbiologist said that reaeration would not be needed except in the case of gross overdosing with sulfur dioxide. Other chemicals may also be used as dechlorinating agents. In addition, dechlorination with activated carbonp a physi- cal filtering process, not only alleviates the problem of toxicity associated with chlorine but it also may remove some of the potentially toxic chlorinated organics. However, L/From an article entitled, "Toxicity of Wastewater Disinfect- ants," in the July 5, 1974, issue of the EPA News of En- vironmental Research in Cincinnati. z/From a paper entitled, "Effects of Wastewater and Cooling Water Chlorination on Aquatic Life," presented at the Washington State Department of Ecology Disinfection Seminar on May 26, 1976. 27 the costs of dechlorination using activated carbon are 13 to 20 times the cost of dechlorination with sulfur dioxide. Where sufficient land is available, holding chlorinated sewage in a pond or lagoon prior to discharge substantially reduces residual chlorine and its effects. IMPROVING PLANT EFFECTIVENESS AND EFFICIENCY -PERMITS LOWER CHLORINE RESIDUALS Improving the quality of sewage effluent reduces the levels of chlorine needed for good disinfection and thus reduces the toxicity of the sewage effluent. The quality of sewage effluent can be improved by (1) providing a higher c level of treatment and (2) improving the operation and main- tenance of the treatment facility. Many sewage treatment plants use too much chlorine and have high chlorine residuals because of inefficient chlorina- tion systems. Even in designs for new plants, elements of efficient chlorination are often overlooked. We believe State and EPA emphasis on improving chlorination efficiency has been inadequate. Need to improve treatment effectiveness and efficiency In primary treatment, solids are screened out and re- moved by settling. Secondary treatment removes more solid material and uses bacteria to break down the organic matter. By reducing the chlorine-demanding material and the bacteria levels in sewage, it is easier to obtain good disinfection with lower chlorine residuals. Also, the amount of chlori- nated organics is reduced. EPA has estimated that 40 to 50 percent of municipal dischargers will achieve secondary treat- ment by 1977. In addition, the EPA Administrator has pointed out that projects to be completed by 1978 will handle the wastes from approximately 80 percent of the population. As additional treatment plants are brought up to secondary treat- ment, effective disinfection with less chlorine will be pos- sible. c Good plant operation also reduces the chlorine needed for effective disinfection. Operation and maintenance prob- lems which adversely affect water quality are widespread in wastewater treatment plants. An EPA report published in September 1976 reported that overapplication of chlorine was noted at plants in the Willamette Basin, and a large savings of resources could be realized by proper surveillance of chlorine use. 28 I Our recent report on the "Continuing Need for Improved Operation and Maintenance of Municipal Waste Treatment Plants," B-166506, April 11, 1977, stated that many municipalities are not\efficiently operating their wastewater treatment facil- ities at designed pollution-removal levels. The basic causes of operation and maintenance problems include excessive flows of water from nonsewer sources, inadequate laboratory con- trols, lack of sufficient numbers of qualified staff, design deficiencies, inadequate budgets, and industrial wastes which upset treatment processes. Another recent report, "Improve- ment Needed in Operating and Maintaining Waste Water Treat- ment Plants," June 18, 1976, B-166506, stated that, of the Department of Defense waste treatment plants examined, 50 per- cent were understaffed and that there was a need for addi- tional operator training. The two reports included a number of recommendations for improving the operation and mainte- nance of treatment plants. Need to improve chlorination efficiency Because most plants do not vary the amounts of chlorine in proportion to the flow of wastewater, they use excessive amounts of chlorine. In addition, most plants use extra chlorine to compensate for contact times which are too short and/or for poor initial mixing. Flow-proportional dosage adjustment A procedural manual for evaluating the performance of wastewater treatment plants, prepared under EPA contract and published in 1972, states that all chlorination equipment used to disinfect wastewater effluent should at least provide for chlorine dosages which are proportionate to the effluent flow. If dosage adjustment must be done manually, a dosage set to achieve adequate disinfection at higher flows, unless manually reset, overchlorinates at lower flows. Amounts and concentrations of sewage vary substantially throughout the day, and a California Department of Health official told us a chlorinator set to dispense a dosage producing a 1,000 ppb residual at peak flow may produce a residual many times higher at low flow. In our survey of about 400 sewage treatment plants from five EPA regions, more than 82 percent of the plants using chlorine reported they still adjusted chlorine doses man- ually, and less than 23 percent of the plants that adjusted manually were staffed continuously. About 33 percent of the plants that adjusted manually did not adjust daily. In some cases chlorination rates appear to be set in periods of high flow (winter) and are not adjusted downward as dry weather approaches. 29 Contact times Increasing contact time between sewage and chlorine permits disinfection with less chlorine residuals. The May 1974 California Interim Manual for Wastewater Chlorination and Dechlorination Practices, written by nationally known disinfection experts, and an EPA technical bulletin published in July 1974, both recommended a contact time between the sewage and the chlorine of at least 30 minutes at peak flow. If the contact time is shorter than this, even for a portion of the sewage, an unnecessarily high amount of chlorine is needed for good disinfection, and in some cases good disin- fection cannot be achieved in spite of high residuals. In our survey of sewage plants, 43 percent of those practicing chlorination were not designed to provide even 30 minutes contact time. The actual contact time for the portion of the sewage that passes through the system fastest is generally far less than the theoretical contact time. Researchers have recommended a minimum 4O:l length-to- width ratio for the contact chamber to allow for adequate contact times. Baffling may permit a poorly designed rec- tangular chamber to attain this ratio. Many basins, however, have length-to-width ratios of 2:l or less and extremely in- adequate baffling. (See pictures on pp. 32 and 33.) An official of the California Water Resources Control Board told us that in many plants baffles could be added quickly and cheaply to improve contact times. Actual chlorine contact times can be measured by dye- tests, with minimum times being measured by the time it takes for the first dye to pass through the contact chamber. In our survey of sewage treatment plants using chlorine, 54 percent had never conducted such a test, and another 30 per- cent did not know if such tests had ever been conducted. Initial mixing Rapid and thorough initial mixing of wastewater with chlorine is needed for efficient chlorination. To achieve good initial mixing, it is necessary to apply chlorine in conditions of turbulent flow or by mechanical mixing. How- ever, specialists in sewage treatment told us it is common practice for the chlorine solution to be applied directly to chlorine contact basins or to open channels. More than two-thirds of the plants we studied had no special device-- hydraulic or mechanical-- to provide rapid mixing of chlorine and wastewater. An official of the Maryland State Water Resources Administration told us that existing chlorination facilities can be modified by adding mechanical mixers to im- prove initial mixing.. 30 Lack of State and EPA emphasis on chlorination efficiencv Neither EPA nor the States have effectively used the National Pollution Discharge Elimination System (NPDES) pro- gram to improve the efficiency of existing chlorination fa- cilities. In addition, neither EPA nor the States have ade- quately reviewed plans and specifications for new construc- tion of chlorination facilities to ensure chlorination effi- ciency. An official of EPA's Municipal Permits Section said that EPA could include requirements for specific equipment in NPDES permits but it avoids doing so because of the problem of liability if the equipment does not achieve the desired objective. In a recent report entitled, "Continuing Need for Improved Operation and Maintenance of Municipal Waste Treatments Plants," B-166506, April 11, 1977, we recommended using the NPDES pollutant discharge permits to require spe- cific actions at existing plants that would help improve plant operation and maintenance (for example, installing selected instrumentation). A similar approach could be used to improve the existing plants chlorination practices. In our survey of State policies and practices, less than 12 percent of the States said they required rapid mixing de- vices--hydraulic or mechanical --as a permit condition. Less than 16 percent said they required automatic dosage control for sewage treatment plants. Only about 40 percent required adequate contact times, and, of these, only 2 out of 18 re- quired as much as 30 minutes at peak flow. No States re- ported that they required dye testing of minimum contact times, and less than 10 percent required a minimum length-to width ratio for the contact chamber. EPA's review of plans and specifications for new chlo- rination facilities is inadequate. Our review of 20 sewage treatment plant designs approved in EPA region III (Philadel- phia), from July 1, 1974, through December 31, 1975, indi- cated the lack of review for elements of efficient chlorina- tion. Of the 20 plants, designs for 3 were approved without automatic dosage adjustment of chlorine. Only 4 of the 20 plant designs provided for even a contact time of 30 min- utes at peak flow. Ten had a contact time of 15 minutes, and six had a contact time of less than 15 minutes. None met the 40~1 length-to-width ratio; rather, they ranged from 1:l to 33:l. Seven of the 20 plant designs provided for the addition of chlorine inside the chlorine contact chamber without mechanical mixing. According to EPA engineers, ini- tial mixing was accomplished by turbulence of the wastewater as it entered the chlorine contact tank. At the insistence 31 EXAMPLES OF POOR BAFFLING IN CHLORINE CONTACT CHAMBERS THE CHLORINE CONTACT CHAMBER AT THIS PLANT HAD ONLY TWO BAF- FLES RESULTING lN LESS THAN ADEQUATE CONTACT TIME. THE SEWAGE FLOWING INTO THIS CHLORINE CONTACT CHAMBER IS BYPASSING THE INITIAL BAFFLES. 32 EXAMPLES OF GOOD BAFFLING IN CHLORINE CONTACT CHAMBERS BOTH OF THESE CHLORINE CONTACT CHAMBERS HAVE GOOD BAFFLING ALLOWING ADEQUATE CONTACT TIME. 33 of a State director concerned with the adequacy of mixing, plans for an eighth facility, originally designed to include an in-tank diffuser, were amended to include mechanical mixing. An EPA technical bulletin recommended that the chlorine be rapidly and thoroughly mixed with the wastewater,prior to its entering the chlorine contact chamber l/, and experts have stated that mixing inside the contact-chamber should be avoided. 2/ For these reasons, we concluded that the designs for the seven facilities would not ensure a sufficiently rapid and thorough initial mixing of chlorine and wastewater. In EPA region I (Boston), we reviewed plans and specifi- cations for 15 wastewater treatment plants'approved between July 1, 1974, and December 31, 1974. In eight cases, mixing was effected by the natural turbulence of the wastewater as it flowed across a chlorine diffuser. Two of the plants lacked automatic dosage control, and 11 of them provided less than 30 minutes contact time at peak design flow. Length-to- width ratios for the 14 plants having chlorine contact tanks generally fell far short of the desired 4O:l ratio. Seven provided less than 20:1, and three of these provided less than 1O:l. We examined construction review guidelines from all EPA regions included in our review and found little evidence of EPA concern with minimizing chlorine residuals by efficient chlorination except in Seattle (region X) and Kansas City (region VII). Region X has published design guidelines which, in part, require that --chlorine contact tanks be sized to provide each mole- cule of water with an actual contact time of not less than 30 minutes at peak flow; --the actual contact time be verified by dye testing or an equivalent method during start-up of the disinfec- tion facilities; --hydraulic or mechanical rapid-mix facilities be de- signed ahead of the contact tanks or basins; and -l/A technical bulletin entitled, "Protection of Shellfish Waters," published in July 1974 by the EPA Office of Water Program Operations. z/Reported in the support for a full-scale study of waste- water disinfection by a California Department of Health Senior Sanitary Engineer. 34 --automatic dosage adjustment be used for larger plants. For new construction, only about 43 percent of the States require a special mixing device--hydraulic or mechan- ical-- to ensure good initial mixing. Only slightly more than 40 percent require automatic dosage control in new construc- tion. While nearly all States require a minimum contact time at peak flow, only eight States require at least a contact time of 30 minutes at peak flows. Only 3 States require dye testing to assure actual minimum contact times prior to acceptance of new construction, and only 21--about 43 percent-- require any specific length-to-width ratio. In February 1976 EPA published a handbook of procedures for the construction grants program. The handbook contains a recommended checklist for the review of treatment facility plans and specifications. The checklist contains a section on chlorination facilities but it does not specify acceptable design or equipment requirements, such as rapid, thorough initial mixing and flow-proportional dosage adjustment; nor does the checklist refer to EPA technical bulletins that contain guidelines for regional and State personnel in re- viewing construction grant projects. A manual of design and practice for wastewater chlorination systems is also being developed by the State of California for the EPA Office of Research and Development. CONCLUSIONS m----m--- Sewage chlorination may be needed in certain specific circumstances. When it is practiced, however, residual chlo- rine is generally discharged far in excess of levels safe to aquatic life. Unnecessary use of chlorine contributes to energy sources being unnecessarily reduced since extensive amounts of energy are needed to produce chlorine. Although chlorine residuals are clearly toxic, improved sewage treat- ment and more efficient chlorination would allow disinfection with lower chlorine residuals. However, EPA and the States have generally failed to use NPDES permits to require sewage treatment plants to use specific pieces of equipment which would significantly improve chlorination efficiency. In re- viewing plans and specifications for new construction, EPA and the States have also generally failed to require effi- cient chlorination facilities. RECOMMENDATIONS --s----c-- We recommend that the Administrator, EPA: --When disinfection is deemed necessary for the protec- tion of the public health, include chlorine residual 35 limitations in all NPDES permits for sewage treatment plants and for all industrial dischargers of chlori- nated effluents. --Lower the limitation on chlorine residuals in power- plant effluents. --Require regional offices or the States, where appro- priate, to tailor NPDES permits to assure the use of chlorine testing and operating equipment which would significantly improve chlorination efficiency at in- dividual treatment plants. --Incorporate efficient chlorination factors, such as rapid, thorough, initial mixing and flow-proportional dosage adjustment, into construction review criteria for all new plant construction. 36 APPENDIX I APPENDIX I REVIEW OF EPIDEMIOLOGICAL STUDIES OF DISEASE TRANSMISSION BY SWIMMING ----------------------------- IN POLLUTED WATERS -------------mm- Epidemiological studies attempting to demonstrate the differences in bacterial levels in bathing waters to levels of illness in swimmers have been inconclusive. A cause-and- effect relationship, at the bacterial levels typically found in the United States today, is questionable considering the amount of swimming done by the American public, the number of polluted beaches and old swimming holes, and the insig- nificant number of illnesses related to water contact. Mar- ginal beaches and areas used by bathers despite high bac- terial levels have had an extremely favorable epidemiolog- ical record. The few studies conducted on bathing water quality and health have been, at best, inconclusive. In a 1961 study 1/ of salt water beaches on Long Island Sound, New York, no relationship between illness and water quality was observed. A 5-year British study l/ came to a similar conclusion, namely, that unless there were large visible amounts of human waste in the water, there was lit- tle risk to the health of bathers in salt water. A 1951 study at two Chicago beaches 2/ found a generally lower ratio of swimmer illness to nonswimmer illness preva- lent at the poorer quality beach. In addition, the percentage of illnesses reported as gastrointestinal was smaller at the poorer quality beach. Illness data were analyzed in various ways in an attempt to correlate illness with exposure to bath- ing waters of varying bacterial densities. Only one method of analysis offered any suggestion of a positive result--evi- dence of a higher illness incidence following 3 days of swim- ming in high bacterial density waters compared to 3 days of swimming in low bacterial density waters. Additional analy- sis, however, tended to refute the suggestion of a relation- ship between bacterial (coliform) levels and disease. . L/Reported in Water Quality Criteria 1972, a report of the Committee on Water Quality Criteria, National Academy of Sciences-National Academy of Engineering. z/"A Study of Bathing Water Quality on the Chicago Lake Front and Its Relation to Health of Bathers," Public Health Serv- ice Environmental Health Center, Cincinnati, Ohio. 37 APPENDIX I APPENDIX I A 1952 study 1/ compared the incidence of disease among persons swimming iz a heavily polluted river and persons swimming in a well-chlorinated swimming pool and found that: (a) The group that did most of its swimming in the chlo- rinated swimming pool apparently had the greatest number of illnesses. (b) There was no correlation between the bacterial qual- ity of the river water and the general illness inci- dence experienced by the bathers. (c) Pool swimmers showed a tendency to have more ill- ness of nongastrointestinal types (i.e., eye, ear, nose, throat, and skin) than did river swimmers. (d) River swimmers showed a statistically significant tendency to have more gastrointestinal illness than pool swimmers, although the number of gastrointes- tinal illnesses reported by river swimmers was only 53 in over 3,700 swimmer-days, 13 more than statis- tically expected. A 1974 study 2/ of illnesses related to two bathing beaches-- a relatively unpolluted beach and a barely accept- able beach-- found that the rate of subsequent vomiting, diar- rhea, and stomach ache was significantly higher among swim- mers (4.2 percent) relative to nonswimmers (2.6 percent) at the barely acceptable beach but not at the relatively unpol- luted beach (3.9 vs. 3.5 percent). This overall finding was highly dependent on illnesses experienced by children under age 10 --unusually high both for swimmers on the barely ac- ceptable beach and for nonswimmers on the relatively unpol- luted beach. Other data suggested that, within the range studied, ocean water quality is not related to rates of swim- mer illness: (a) The rate of swimmer gastronintestinal illness at the barely acceptable beach (4.2 percent) was not L/"A Study of Bathing Water Quality on the Ohio River at Day- ton, Kentucky, and Its Relation to Health of Bathers," Pub- lic Health Service Environmental Health Center, Cincinnati, . Ohio. Z/A draft paper on the Relationship of Microbial Indicators to Health Effects at Marine Bathing Beaches, EPA Health Effects Research Laboratory, Cincinnati, Ohio. 38 APPENDIX I APPENDIX I substantially different from that at the relatively unpolluted beach (3.9 percent) for persons over age 9; the rate at the relatively unpolluted beach (4.2 percent) was actually higher than that at the barely acceptable beach (3.7 percent) in spite of the fact that the barely acceptable beach was imme- diately adjacent to a beach posted as unsafe for swimming, and the data suggested an immediate source of raw fecal wastes. (b) For persons over age 9, the gastrointestinal illness rate associated with swimming (i.e., swimmer rate minus nonswimmer rate) on the relatively unpolluted beach (1.0 percent) was actually higher than that on the barely acceptable beach (0.8 percent); for per- sons over age 19, the gastrointestinal illness rate associated with swimming on the relatively unpolluted beach (1.3 percent) was nearly twice as great as that on the barely acceptable beach (0.7 percent). (c) Ethnic differences may account for the unusually high rate of illness associated with swimming, for chil- dren under 10, at the barely acceptable beach. The Latin Americans in the study experienced much higher swimming-associated illness rates, were more likely to swim than non-Latins, and constituted a much higher percentage of the beach population at the barely acceptable beach (54 percent) than at the relatively unpolluted beach (20 percent). 39 APPENDIX II APPENDIX II ALTERNATIVES TO CHLORINE FOR SEWAGE DISINFECTION LAND APPLICATION Land application frequently provides an effective way to remove harmful bacteria and viruses (and other pollutants) from wastewater. In addition, nutrients in wastewater enrich the land. Treated sewage is used for irrigation of crops, pasture lands, orchards, and vineyards; and for watering parks, golf courses, freeway landscapes, and forests. There are, however, disadvantages which limit the applicability of land treatment: --Local conditions have a major effect on applicability and economic feasibilty. --Each land application site generally requires a design produced specifically for it to preclude serious ad- verse environmental impacts; such designs frequently require input from a number of specialized profes- sions. --Harmful bacteria may survive for periods of a few days to several weeks or more in the soil and crops, and it may be transmitted when spray irrigation is used. Ac- cording to several experts, when chlorine disinfection is practiced prior to land treatment, the effects of the chlorine residual on the soil are not known. --Irrigation of pasture lands and of crops which are consumed raw may subject animals and humans to worm infestations. The eggs or intermediate forms of the organisms are resistant to both sewage treatment proc- esses and chlorination. WASTEWATER TREATMENT PONDS (LAGOONS) There are over 5,000 wastewater treatment ponds in the United States representing about 25 percent of all wastewater treatment facilities and 90 percent of the facilities in com- munities under 5,000 people. Well designed wastewater lagoons can reach disinfection standards without chlorination prior to discharge but they cannot normally meet suspended solids standards consistently. Most facilities could be economically upgraded to meet suspended solids standards. They require large tracts of land, however, and the cost of land for evaporation ponds is not an eligible cost for Fed- eral construction grants. Most lagoons are, therefore, con- structed in areas where land is readily available. 40 APPENDIX II APPENDIX II OZONATION -_I- Ozone has received the most attention as a disinfectant alternative to chlorine. Ozone has been used for 60 years to treat drinking water supplies in Europe and Canada. Its use in wastewater applications has been generally limited to pilot plant studies. Ozonated effluents appear to be less toxic than chlorinated effluents to aquatic life. Ozonation is also effective against viruses. In order to be an effec- tive disinfectant, however, ozone requires a highly treated effluent (beyond secondary treatment) at all times and/or very high doses of ozone. Even without the cost of the addi- tional treatment or high dosage, ozonation costs considerably more than chlorination/dechlorination and its production con- sumes considerably more energy than chlorine production. As with chlorine, toxic compounds may be formed from reaction of ozone with organics. ULTRAVIOLET --pm RADIAT-ION Ultraviolet radiation has seen limited use in wastewater disinfection. It is not toxic to the aquatic environment, but it is more expensive than chlorine, and, for adequate disinfection, a high quality effluent (beyond secondary treat- ment) must be provided. BROMINE -- CHLORIDE Bromine chloride, at an equal dosage with chlorine, will provide comparable bacterial disinf.ection and better viral disinfection. Brominated effluent may be as toxic as chlori- nated effluent, but its residual toxicity is much shorter- lived. Existing chlorination facilities would require only minor modifications to convert from chlorine to bromine chlo- ride. The cost may be considerably higher than that of chlo- rine, however, and the toxicity of brominated organic com- pounds is generally greater than that of the corresponding chlorine compounds. 41 APPENDIX III APPENDIX III LIST OF SUGGESTED REFERENCES Ad Hoc Study Group, "A Report Assessment of Health Risk from Organics in Drinking Water," Science Advisory Board, U.S. Environmental Protection Agency, April 30, 1975. American Water Works Association, "Water Chlorination Prin- ciples and Practices," American Water Works Asociation, New York, 1973. Benenson, Abram S, (ed.)p Control of Communicable Diseases in Man, 12th ed., American Public Health Association, 1975. Blogoslawski, Walter J. and Mary Elizabeth Stewart, Marine Applications of Ozone Water Treatment. Brungs, William A., "Effects of Residual Chlorine on Aquatic Life," Journal Water Pollution Control Federation, Washing- ton, D.C. Brungs, William A., "Effects of Wastewater and Cooling Water Chlorination on Aquatic Life," Program Element lBA608. Brungs, William A., "Effects of Wastewater Chlorination on Freshwater Aquatic Lifee" October 1975. Bureau of Sanitary Engineering, State of California Depart- ment of Public Health, "Wastewater Chlorination for Public Health Protection," Proceedings Fifth Annual Sanitary Engi- neering Symposium, May, 1970. Cabelli, Victor J., Alfred P. Dufour, Morris A. Levin, Leland J. McCabe, Paul W. Haberman, "Relationship of Micro- bial Indicators to Health Effects At Marine Bathing Beaches," Health Effects Research Laboratory Cincinnati, U.S. Environmental Protection Agency, Rhode Island, Center for Policy Research, New York. Cabelli, Victor J. and Leland J. McCabe, "Recreational Water Quality Criteria," News of Environmental Research in Cin- cinnati, U.S. Environmental Protection Agency, November 11, 1974. Cabelli, Victor J., Harriet Kennedy, and Morris A. Levin, "Pseudomonas Aeruginosa-fecal coliform relationships in estuarine and fresh recreational waterslm Journal of the Water Pollution Control Federation, vol. 48, no, 2, Feb- ruary 1976, 42 APPENDIX III APPENDIX III Cabelli, V.J., M.A. Levin, A.P. Dufourp and J.J. McCabe, "The Development of Criteria for Recreational Waters," U.S. Environmental Protection Agency, Recreational Water Cri- teria Program, National Environmental Research Center, Cincinnati, Ohio 1975. California State Water Resources Control Board, "Long Term Effects of Toxicants and Biostimulants on the Waters of Central San Francisco Bay," Publication no. 51, 1974. Chambers, Cecil W., "Chlorination for Control of Bacteria and Viruses In Treatment Plant Effluents,' Journal, February 1971. Collins, Harvey F. and David G. Deaner, "Sewage Chlorination Versus Toxicity-A Dilemma?" Journal of the Environmental Engineering Division, December 1973. Collins, Harvey F., George C. White, and Endel Sepp, "Interim Manual for Wastewater Chlorination and Dechlorination Prac- tices," the State Water Resources Control Board, California, 1974. Cookson, John T., Jr., "Virus and Water Supply," December 1974. Coordinating Council for Vocational Education, Division of Vocational Education, "Waste Water Plant Operators Manual," State of Washington. Gulp, Russell L., "Breakpoint Chlorination for Virus Inacti- vation,' Journal, December 1974. Gulp, Russell L.I "Virus and Bacteria Removal in Advanced Wastewater Treatment," Public Works for June 1971. Deanp Robert B., "Toxicity of Wastewater Disinfectants," News of Environmental Research in Cincinnati, U.S. Environmental Protection Agency, July 5, 1974. Deaner, David G., "Chlorine Contact Chamber Study at Redding Sewage Treatment Plant," Bureau of Sanitary Engineering, State of California - Human Relations Agency, Department of Public Health, 1970. Department of the Army Corps of Engineers, 'Assessment of the Effectiveness and Effects of Land Disposal Methodologies of Wastewater Managementpn Wastewater Management Report 72-1, January 1972. 43 APPENDIX III APPENDIX III Earampamoorthy, Sinnadurai, and Raymond S. Koff, "Health Hazards of Bivalve-Mollusk Ingestion," Annals of Internal Medicine 83:107-110, 1975. Esvelt, Larry A., Warren J. Kaufman, Robert E. Selleck, "Toxicity Assessment of Treated Municipal Wastewaters," pre- sented at the 44th Annual Conference of the Water Pollution Control Federation, San Francisco, California, October 4-8, 1971. * Esvelt, Larry A., ------ Toxicity Removal From Municipal Wastewaters, Volume IV of a Study o~-ToxiSity-ana-sios~i~~~~i~insan Francisco Bay-Delta Waters for the State Water Resources r Control Board Under Standard Agreement No. 260809, Octo- ber 1971. Fugs, G. Wolfgang, "A Probablistic Model of Bathing Beach Safety, "The Science of the Total Environment, Elsevier Sci- entific P~~i~~ns-~mpany,Amsterdam,----- Geldreich, Coastal Edwin E., Bathing Microbiological Wat-~-y-------"-----~--T--- Criteria Concepts for ---------~----- Elsevier Scientific Publishing Company, Amsterdam, Ocean Management, 3 (1974-75) 225-248. Genetelli, Emil J., B.A. Lubetkin, and J. Cirello, Chlorina- ----- tion of ------------- Wastewater Effluents A --y----v------ Critical Review. Harr, Thomas E., "Residual Chlorine in Wastewater Effluents Resulting from Disinfection," Environmental Quality Research Unit Technical Paper No. 38, March 1975. Harvard University, "Formation of Halogenated Organics by Chlorination of Water Supplies," March 26, 1975. Heukelekian, H. and S.D. Faust, "Compatibility of Wastewater Disinfection by Chlorination," presented at the Annual Meet- ing of the Pennsylvania Water Pollution Control Association in University Park, Pa., on August 10-12, 1960. Huff, E. Scott, "Diligent Chlorination Practices Yield Mul- tiple Savings," Water --------_I- & Sewage Works, July 1976. Huggett, Robert J., and Michael E. Bender, Investigations -- of Two Estuarine Fish -------~--------_uI-----~~~~--~-~ Kills Caused by ChlEiri?ie ResiauaTs. Ingols, Robert S., "Chlorination of Water-Potable, Possibly: Wastewater, No! ," -------m-e--- Water & Sewage Works, February 1975. Jolley, Robert L. (ed.), Proceedings of the Conference on the Environmental Impact of Water Chlorination, Oak Ridge Na- tional Laboratory, Energy Research and Development Adminis- tration, U.S. Environmental Protection Agency, July 1976. 44 APPENDIX III APPENDIX III Lewis, Ronald R. and John M. Smith, "Upgrading Existing Lagoons," National Environmental Research Center, Advanced Waste Treatment Research Laboratory, Office of Research and Development, Cincinnati, Ohio, October 1973. Lue-Hing, Cecil, Bart T. Lynam, David R. Zenz, "Wastewater Disinfection: The Case Against Chlorination," The Metro- politan Sanitary District of Greater Chicago, Department of Research and Development, report no. 76-17, June 1976. f Martens, D.W. and J.A. Servizi, "Dechlorination of Municipal Sewage Using Sulfur Dioxide," Progress Report No. 32, In- ternational Pacific Salmon Fisheries Commission, Canada, 1975. McCarthy, Jeremiah J., and Cecil H. Smith, "A Review of Ozone and Its Application to Domestic Wastewater Treatment," Journal AWWA, December 1974. Middlebrooks, E. Joe, Donna H. Falkenborg, Ronald R. Lewis, and Donald J. Ehreth (eds.), "Upgrading Wastewater Stabili- zation Ponds to Meet New Discharge Standards," Symposium Proceeding, November 1974. National Academy of Sciences and National Academy of Engi- neering, Water Quality Criteria 1972, A Report of the Com- mittee on Water Quality Criteria, Washington, D.C., 1972. Old, H.N., and S.L. Gill, "A Typhoid Fever Epidemic Caused by Carrier "Bootlegging" Oystersl" read before the Engineering Section of the American Public Health Association at the Sixty-eight Annual Meeting in Pittsburgh, Pa., October 1939. Robson, C.M., B.S. Hyatt, Jr., and S.K. Banerji, "We Must Improve Chlorination Design," Water and Waste Engineering, September 1975. Sew Endel, The Use of Sewaqe for Irriqation A Literature Review, Bureau of Sanitary Engineering, State of California- Human Relations Agency, Department of Public Health, re- vised 1971. Silvey, J.K.G., R.L. Abshire, and W.J. Nunez III, "Bacterio- i logy of Chlorinated and Unchlorinated Wastewater Effluents," Journal, vol 46, no. 9, September 1974. Smith, Russell S., et al., "Bathing Water Quality and Health I-Great Lakes," Environmental Health Center, Cincinnati, Ohio, 1951. 45 APPENDIX III APPENDIX III Smith, Russell S., "Bathing Water Quality and Health-II Inland River," Environmental Health Center, Cincinnati, Ohio, 1952. Stanier, Roger Y., Michael Doudoroff, and Edward A. Adelberg, The Microbial World, 2nd ed., Prentice-Hall, Inc., Engle- wood Cliffs, N.J., 1963. The Journal of Infectious Diseases, "Outbreaks of Waterborne Diseases in the United States, 1961-1970," vol. 125, No. 3, March 1972. * The Journal of Infectious Diseases, "Outbreaks of Waterborne Diseases in the United States, 1971-1972," vol. 129, no. 5, May 1974. 6 The Journal of Infectious Diseases, "Outbreaks of Waterborne Diseases in the United States, 1973," vol. 132, no. 3, Sep- tember 1975. Tsai, Chu-fa, "Effects of Sewage Treatment Plant Effluents on Fish: A Review of Literaturepn Chesapeake Research Con- sortium, Inc., March 1975. U.S. Department of Health, Education, and Welfare, "Hepatitis Surveillance," report no. 23, June 30, 1965. U.S. Department of Health, Education, and Welfare, "Prevalence of Selected Chronic Digestive Conditions, United States- July-December 1968," publication no. (HRA) 74-1510, series 10, no. 83, September 1973. U.S. Department of Health, Education, and Welfare, Reported Morbidity and Mortality In the United States 1974, vol. 23, no. 53, Center for Disease Control, Public Health Service, Atlanta, Georgia, for year ending December 28, 1974. U.S. Environmental Protection Agency, "Disinfection of Waste- water," task force report, General Services Administration, Denver, EPA-430/g-75-012, March 1976. u-s. Environmental Protection Agency, "Fish Kills Caused By Pollution In 1972," Thirteenth Annual Report, Government Printing Office, EPA-440/g-73-001. U.S. Environmental Protection Agency, "Fish Kills Caused By Pollution In 1973," Fourteenth Annual Report, Government Printing Office, EPA-440/g-75-003. U.S. Environmental Protection Agency, "Land Treatment of Mu- nicipal Wastewater Effluents," Case Histories, EPA Technol- ogy Transfer Seminar Publication, January 1976. 46 APPENDIX III APPENDIX III U.S. Environmental Protection Agency, "Land Treatment of Municipal Wastewater Effluents," Design Factors-I, EPA Technology Transfer Seminar Publication, January 1976. U.S. Environmental Protection Agency, "Land Treatment of Municipal Wastewater Effluents," Design Factors-II, EPA Technology Transfer Seminar Publication, January 1976. U.S. Environmental Protection Agency, "Preliminary Assessment of Suspected Carcinogens in Drinking Water," An Interim Report to the Congress, June 1975. U.S. Environmental Protection Agency, "Preliminary Draft Qual- ity Criteria tar Water," October 10, 1975. U.S. Environmental Protection Agency, Process Design Manual for Upgrading Existing Wastewater Treatment Plants, "Dis- infection and Odor Control," ch. 9. U.S. Environmental Protection Agency, "Protection of Shellfish Waters," July 1974 EPA 430/g-74-010. U.S. Environmental Protection Agency, "The Economies of Clean Water-1973," December 1973. Weibel, S.R., F.R. Dixon, R.B. Weidner, and L.J. McCabe, '-'Waterborne-Disease Outbreaks, 1946-60," A paper presented on Nov. 1, 1962, at the Ohio Section Meeting, Cincinnati, Ohio. Wheeland, Hoyt A. and B.G. Thompson, "Fisheries of the United States, 1974," United States Department of Commerce, Na- tional Oceanic and Atmospheric Administration, National Marine Fisheries Service, Washington, D.C., March 1975. World Health Statistics Annual - 1972, vol. 1, Vital Sta- tistics and Causes of Death, world Health Organization, 1975. 47 APPENDIX IV APPEDIX IV PRINCIPAL EPA OFFICIALS RESPONSIBLE FOR ACTIVITIES DISCUSSED IN THIS REPORT Tenure of office From -To ADMINISTRATOR: Douglas M. Costle Mar. 1977 Present John R. Quarles, Jr. (acting) Jan. 1977 Mar. 1977 Russell E. Train Sept. 1973 Jan. 1977 John R. Quarles, Jr. (acting) Aug. 1973 Sept. 1973 Robert W. Fri (acting) Apr. 1973 Aug. 1973 William D. Ruckelshaus Dec. 1970 Apr. 1973 ASSISTANT ADMINISTRATOR FOR WATER AND HAZARDOUS MATERIALS: Thomas C. Jorling June 1977 Present Dr. Andrew Breidenback Sept. 1975 June 1977 James L. Agee Apr. 1974 Sept. 1975 Roger Strelow (acting) (note a) Feb. 1974 Apr. 1974 Robert L. Sansom (note a) Apr. 1972 Feb. 1974 DEPUTY ASSISTANT ADMINISTRATOR FOR WATER PROGRAM OPERATIONS: John T. Rhett Mar. 1973 Present Louis De Camp (acting) Sept. 1972 Mar. 1973 Eugene T. Jensen June 1971 Sept. 1972 a/Before April 22, 1974, the title of this position was Assistant Administrator for Air and Water Programs. 08742 48 Copies of GAO reports are available to the general publrc at a cost of $1.00 a copy. There is no charge for reports furnished to Members of Congress and congressional committee staff members. Officials of Federal, State, and local governments may receive up to 10 copres free of charge. 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Unnecessary and Harmful Levels of Domestic Sewage Chlorination Should Be Stopped
Published by the Government Accountability Office on 1977-08-30.
Below is a raw (and likely hideous) rendition of the original report. (PDF)