Man Fishing in the River
Why does wastewater regulation matter for rivers?

Wastewater from municipal and industrial sources has historically been one of the most serious threats to water quality. Discharging bacteria, industrial waste products, pharmaceuticals, and many other waste products damage our waters. These nutrients contribute to excessive plant growth in our rivers, and deplete oxygen necessary to support aquatic species health. High levels of chemical buildup harm species living in or along rivers, while also affecting downstream communities that use rivers for drinking water. Unfortunately, many Massachusetts waterways still suffer from nutrient pollution from wastewater treatment plants, including the Assabet and Blackstone Rivers.

The Clean Water Act, passed in 1972, created the National Pollution Discharge Elimination System (NPDES) Program to address these ‘point’ sources of discharge. Industrial polluters receive permits from EPA that limit how much they can discharge into waterways.


In Massachusetts the NPDES program is responsible for successful efforts to restore and protect the Assabet River, which has four municipal wastewater treatment plant discharges along its course and very high levels of phosphorus in its water. To learn more about wastewater issues on the Assabet, go to http://www.oars3rivers.org/threats/water-pollution/tmdl.

The health of the Charles River, the Nashua, the Blackstone, and Boston Harbor have also greatly improved, thanks to the NPDES program.