If your water is supplied by a city water system (such as in Santa Fe) or a community water system (such as in Eldorado), U.S. Environmental Protection Agency (EPA) regulations govern contaminant compliance and monitoring. EPA regulations do not apply to private water wells, so if you're dependent on a private well you're on your own! The good news is that EPA standards are useful guidelines for well-water treatment.

The Safe Drinking Water Act, passed by Congress in 1974 and amended in 1986 and 1996, gives the EPA authority to set drinking-water standards. The EPA is charged with assessing and protecting public drinking-water sources and collection systems, making sure that water is treated by qualified operators, ensuring the integrity of distribution systems, and making information about the quality of drinking water available to the public.

There are two categories of drinking water standards: primary and secondary. Primary standards deal with micro-organisms, disinfectants, disinfection byproducts, inorganic chemicals, organic chemicals, and radionuclides. These standards limit levels of contaminants that can adversely affect public health and are known or anticipated to occur in water. These standards, listed as maximum contaminant levels (MCLs), are enforceable and are defined as the highest level of a contaminant allowable in drinking water. The EPA also sets MCL goals, which are non-enforceable public health goals. For some contaminants, treatment techniques are set rather than MCLs.

City and community water systems, which are defined as public water systems that have at least 15 service connections used by year-round residents, fall under EPA regulations and are required by law to meet EPA drinking-water standards. In New Mexico these systems must also comply with State of New Mexico drinking-water regulations. Community systems are tested at regular intervals and are closely monitored for compliance with MCL levels. Compliance testing is conducted by the New Mexico Environment Department's Drinking Water Bureau and is a matter of public record.

The EPA's Consumer Confidence Rule requires that public water suppliers provide a consumer confidence report (CCR) to their customers. These reports are also known as annual water quality reports or drinking water quality reports and contain information regarding supply sources (rivers, lakes, reservoirs, and aquifers), any contaminants detected, compliance efforts, and educational information. In

Santa Fe, these reports are distributed annually to Sangre de Cristo Water Division customers.
Secondary standards are the EPA's recommended, non-enforceable guidelines regarding contaminants that may cause cosmetic effects (such as skin or tooth discoloration) or aesthetic effects (such as taste, odor or color) in drinking water. Iron and manganese, which may result in staining, are included on this list. There is no EPA standard for hardness, which many Santa Feans find to be the most annoying contaminant of all.

The EPA recommends, but does not require, annual testing of private water supplies for coliform bacteria, total dissolved solids, and pH levels for early detection of contamination problems. In addition to contaminants that commonly occur in wells, residents of the Santa Fe area should also be cognizant of possible contamination by naturally-occurring radionuclides.

Stephen Wiman has a background in earth science (Ph.D. in geology) and is the owner of Good Water Company in Santa Fe. He may be reached at 505-471-9036 or skwiman@goodwatercompany.com.

Originally published 3/4/2007 in Santa Fe New Mexican's Real Estate Guide p101