Part 3 in a continuing series of CBA -- What is SDWA? It will be difficult to discuss this issue without understanding the basics of the legislation and what it is supposed to do. Since my free time is short and I can type faster than I can compose my own sentences, I've copied this section from various parts of the CBO study. The next part after this will start to address the CBA section of the study (finally), after a brief pause so that people can digest parts 1-3. ---------------------------------------------------------------------------- Maximum Contaminant Levels -------------------------- "The 1986 amendments directed the EPA to develop regulations for 83 specific contaminants as well as regulations mandating filtration (for those water systems supplied by surface water sources) and disinfection (for all water from all public water supplies). In addition, the law required the EPA to regulate 25 additional contaminants every three years. Since 1986, the EPA has issued seven major regulations that establish standards for either a specific contaminant or groups of contaminants. Under those rules, the EPA sets standards -- called maximum contaminant levels (MCLs) -- for each contaminant." (pg. 6) EPA sets drinking water standards in a two-stage process. First, it establishes maximum contaminant level goals (MCLGs). "MCLGs are nonenforceable health-based goals which are set at the level at which no known or anticipated adverse effects on the health of persons occur and which allows an adequate margin of safety" (EPA, _Technical and Economic Capacity of States and Public Water Systems to Implement Drinking Water Regulations_, Sep 1993, pg. 22). Then EPA sets an enforceable MCL as close to the MCLG as is feasible, "taking costs into consideration." The legislative history of SDWA directs EPA to base feasibility on what is affordable to large systems. (above paragraph paraphrased from pg. 30). Existing and Proposed Rules Under the SDWA as of Sep 1994 (Box 1 on pg. 4-5) --------------------------------------------------------- Existing -------- Fluoride 1986 "Fluorides occur naturally and are added during the treatment process in many water systems. Amount greater than two parts per million can have harmful effects, ranging from discoloration and pitting of teeth to bone and skeletal damage. Systems must test for fluoride. If it is found to be above allowable levels, they must change their operations or take other actions to lower the level." Phase I Volatile Organic Compounds 1987 "Volatile synthetic organic chemicals (VOCs) are man-made compounds used for a variety of industrial and manufacturing purposes in the form of products such as solvents, degreasers, and dry cleaning chemicals. VOCs have adverse effects on the liver, kidneys, and nervous system, and they may cause cancer in humans. Water systems must sample for VOCs. When the compounds are found, the source of the VOCs must be removed or treatment must be undertaken." Surface Water Treatment Rule 1989 "The rule for treating surface water requires treatment to control bacteria and other microbes that are difficult to detect and pose immediate health risks. This rule covers all surface water systems and groundwater systems that are under the direct influence of surface water. The rule requires affected systems to disinfect and install a subset of systems to filter their water. Total Coliform Monitoring 1989 "Total coliform monitoring requirements affect all community water systems. Systems are required to conduct monthly tests for coliform bacteria, which indicate whether potentially harmful bacteria may be in the water. Over the years, bacteria from sewage and animal wastes have presented the most frequent and immediate health risks to community water supplies." Phase II Synthetic Organic Compounds 1990/91 "This rule covers Phase II synthetic organic compounds (SOCs) and nonvolatile man-made compounds, primarily pesticides and polychlorinated biphenyls. Adverse health effects from exposure to SOCs include damage to the nervous system and kidneys and risk of cancer. Vulnerable water systems must test for SOCs. If the contaminents are found, the source of the SOCs must be removed or the water supply must be treated to remove them. Phase II Inorganic Compounds 1990/91 "Phase II inorganic compounds (IOCs) may be naturally occuring in geological structures or they may be caused by mining, industrial, or agricultural activities. In large amounts, these chemicals can damage the liver, kidney, nervous system, circulatory system, blood, gastrointestinal system, bones, or skin. All community water systems must be monitored for regulated IOCs. If IOCs are found, their level must be adequately reduced or treatment must be undertaken." Lead and Copper 1991 "Lead and copper contamination generally occurs after water has left the public water system. Therefore, testing for it should be done at household faucets. Water systems must target homes with a high risk of lead and copper contamination and conduct tests in those locations. If contamination is found, water systems must reduce the corrosiveness of the water or replace materials containing lead under the control of the water system. Water systems are not required to replace customers' pipes containing lead." Phase V SOCs and IOCs 1992 "See the description above for Phase II SOCs and IOCs." Proposed Rules -------------- Radionuclides Rule "The Radionuclides Rule sets standards for radon-222, radium-226, radium-228, uranium, and adjusted gross alpha emitters. Those radionuclides are classified as Group A human carcinogens; in addition, uranium is toxic to kidneys. People can be exposed to radionuclides by drinking tap water that contains them or by inhaling radionuclides released into indoor air from tap water. The proposed rule on radionuclides primarily affects groundwater systems." Disinfectants and Disinfection By-Products "Disinfectants (such as chlorine) are used by over 90 percent of surface water systems and less than one-half of groundwater systems to prevent diseases caused by microbiological contaminants. Although disinfection provides important benefits, the disinfectants themselves can react with organic materials in water supplies to form disnfection by-products. Such byproducts may ultimately increase the risk of cancer. Stage I of the proposed rule would require systems to use existing treatment processes to remove precursors (for example, total organic carbon) of disinfection by-products. Stage II would require systems serving more than 10,000 people to undertake testing and treatment for disinfection by-products. An extended Stage II would expand those requirements to all systems." Enhanced Surface Water Treatment Rule "The rule on enhanced surface water treatment (ESWT) would expand the controls established under the Surface Water Treatment Rule. Additional controls are proposed because of new evidence that exposure to microbial contaminants in surface waters may be significantly greater than previously beleived. In addition, requirements under the proposed rule for disinfectants and disinfection by-products may result in greater risk from microbial contaminants. Under the proposed rule, an "interim" ESWT rule would require additional controls for systems serving more than 10,000 people. A "long-term" ESWT rule would extend those requirements to all systems." Sulfate Rule "The primary adverse health effect of ingested sulfate is diarrhea in unacclimated individuals, who include infants and new residents and visitors to high-sulfate areas. The EPA is proposing four options for regulating sulfate. The preferred option, Option 1, is an alternative to central treatment. Under that option, a system may comply by providing the exposed population with alternative water supplies, establishing and maintaining a public education program, and carrying out a public notice program. Under that option, systems may still opt for central treatment, and almost all large systems are expected to do so."