Updated Resource Compiles, Compares Water Regulations in the Region

NEIWPCC recently completed a major update to our water quality standards matrix, designed to make it easy to compare how the states in the Northeast regulate different water quality parameters.

View from a bridge

The matrix includes criteria for thirty water quality parameters— that is, pollutants or characteristics—that some or all the states regulate, from the aesthetics of water bodies to tritium concentrations (a radioactive hydrogen isotope). Water quality criteria describe what states mean by “clean water,” and are based on the main ways people and wildlife use a water body.

Every state has different regulations in place to preserve and advance water quality. Under the Clean Water Act, the EPA usually delegates their authority to regulate water quality to the states. While states often follow recommendations made by the EPA, they can also set science-based standards which better reflect the unique natural conditions and water resource needs in their state.

NEIWPCC’s matrix helps compare the language states use to describe a parameter as well as the specific criteria states have in place for different designated uses of water bodies.  For example, Connecticut, Maine, New Hampshire, and Rhode Island all follow the EPA’s recommended maximum chloride concentration to protect freshwater aquatic life: 860,000 µg/L. However, New York also regulates chloride concentrations to protect human health in specific water bodies, and has a stricter standard in place for those waters: 250,000 µg/L.

The matrix is available as a searchable, interactive table on our website or to download as a Microsoft Excel spreadsheet. It is intended as an informative guide which we will update periodically. For the most up-to-date information, consult the relevant state regulations, linked below the table. For more information or to provide updates to the matrix, contact Richard Friesner.

If you’re interested in learning more about water quality standards, you can watch recordings from a training NEIWPCC held for state and EPA personnel in 2019. The training was a regional supplement to the EPA’s national Water Quality Standards Academy.