Enacted in 1976, the National Primary Drinking Water Regulations are an outgrowth of the Safe Drinking Water Act (SDWA), and the first to be applied to all public water systems within the United States. These federal regulations protect the 250 million people who are served by public water systems. 

Regulation increases and evolves as the EPA continues to identify water-borne contaminants, sets limits for presence in drinking water, outlines acceptable water treatment techniques, specifies water-testing schedules, and develops analytical methods for water evaluation. Each National Primary Drinking Water Regulation must be reviewed at least once every six years, and any revision must maintain or increase public health protection.

The United States has one of the safest water supplies in the world. However, national statistics don't necessarily reflect the quality of your water. The quality and safety of the water you drink depends on the condition of your specific source, and on the treatment that water receives before it arrives at your tap.

While EPA and state governments set and enforce standards, local governments and private water suppliers are ultimately responsible for your tap water quality.   Water systems test and treat their water, maintain the distribution systems that deliver water to consumers, and report on their water quality to the state. 

Neilson Research Corporation provides analytical testing for public water systems to meet all current state and federal regulation. Our staff maintains a careful watch over ever-changing requirements, as well as testing methods and schedules to assist our clients with regulatory compliance.

Congress requires the EPA to regulate contaminants in public drinking water supplies through the Safe Drinking Water Act. The legal limits set by the EPA reflect both the maximum contaminant level that protects human health and the level that water systems can achieve using the best available technology. In addition to establishing these limits, the EPA sets water-testing schedules and methods that public water systems must follow. The rules also list acceptable water treatment techniques. The Act allows individual states the opportunity to set and enforce their own drinking water standards if the standards are at least as stringent as EPA's national standards. Most states and territories directly oversee the water systems within their borders.

For each contaminant, EPA set a health goal, or MCLG. At this level, a person could drink two liters of water containing the contaminant every day for 70 years without any ill effects. The MCLG is not a legally enforceable limit but a goal for healthy water. For known carcinogens the Agency set the health goal at zero, assuming that any exposure to the chemical presents a cancer risk.

In addition to the health-based MCLG, the rules also set a legal limit for each contaminant. Keeping in mind that technical and financial barriers exist, the EPA sets each legal limit as close to the health goal as is feasible.

Neilson Research Corporation can provide information regarding individual contaminants and their MCLs and MCLGs. Our knowledgeable staff is happy to assist you with any questions you may have regarding regulatory compliance or analytical testing.