Improvements to wastewater treatment plants have drastically cut the amount of sewage polluting the Chesapeake, meeting a key goal in bay cleanup a decade early, environmental officials said Tuesday.
Levels of nitrogen flowing from the plants have fallen 27 percent since 2010, the year the Environmental Protection Agency set long-term standards for how much pollution the bay could withstand. The 38 million pounds of nitrogen now flowing into the bay each year meets that target, which carried a 2025 deadline, officials said.
Along with farms and stormwater runoff, sewage treatment plants are one of the main sources of nitrogen and other nutrients that degrade bay water quality. The pollutants cloud waters, blocking sunlight from reaching underwater plants, and they feed algae blooms that suck oxygen from the water when they die.
The EPA established what is known as the Total Maximum Daily Load, or TMDL, for the bay in 2010. The so-called "pollution diet" sets goals to reduce the amount of pollution flowing into waterways from various sources.
"The wastewater sector is leading the way at this point in our efforts to restore the Bay and local waters," EPA Regional Administrator Shawn M. Garvin said in a statement. "While we’ve reached a critical milestone in reducing pollution from wastewater plants, we need to keep up the momentum and ensure that other sectors do their share."
The officials attributed the gains to technological upgrades to treatment plants, bans on phosphorus detergent and enforcement of Clean Water Act permits.
There are 472 municipal and industrial wastewater treatment plants in the Chesapeake Bay watershed that have been designated as significant sources of nutrient pollution.