Volatile organic chemicals (VOC)-State regulations set Maximum Contamination Levels (MCLs) for 8 chemicals and monitoring requirements for 51 additional contaminants for systems serving less than 3,300 people.
Total Coliform- Public water systems are required to sample for total coliform on a monthly basis. Sampling must be conducted in accordance with a written plan. The number of samples required per month depends on the number of persons served. Systems that serve 25 to 1000 persons, for example, must take 1 sample per month. When a Total Coliform sample is positive, additional testing of the sample must be conducted for fecal coliform and E. coli and repeat samples must be taken. If the repeat sampling and testing indicates fecal coliform or E. coli is present, the public must be notified.
Lead and Copper- Rules for minimizing lead and copper in drinking water have been developed. The regulations include corrosion control treatment, sampling for lead and copper levels in drinking water, water treatment if required, and public education.
Synthetic organic and inorganic chemicals (SOC and IOC)-This rule sets MCLs for 33 contaminants and require monitoring for 110 additional contaminants.
Additional rules are expected to be implemented in the future that will address additional volatile organic and synthetic organic chemicals, radionuclides, radon, disinfectants, arsenic, and many other contaminants.
The expense of conducting the comprehensive testing program mandated by the SDWA will drive up water system costs. The potential for additional expenses which could result if sampling uncovers problems with water systems may far exceed the cost of sampling. For example expensive water treatment could be necessary or some water sources may have to be abandoned and new sources developed (e.g., drill a new well at some distance from the old one and lay pipe to move water to the system).