A partnership created over 30 years ago to restore water quality and replenish aquatic life in the Chesapeake Bay is halfway through a landmark effort to reduce pollution that has choked the world’s third-largest estuary.

“The bay and the watershed are responding because of thousands of actions by our farmers, by our municipalities and homeowners,” said Rich Batiuk, associate director for science, analysis and implementation for the U.S. Environmental Protection Agency.

Batiuk was one of several speakers at the 8th annual conference of the Choose Clean Water Coalition held in Charlottesville this week.

As part of the event, participants were briefed on the status of a pollution diet for the Bay referred to as the Total Maximum Daily Load.

That scientific term is how advocates and scientists refer to the process mandated by the U.S. Environmental Protection Agency in December 2010 that requires states to reduce nitrogen, phosphorous, sediment and other pollutants that reach the bay.

The 4,479 square-mile bay is filled with freshwater that flows from six states and the District of Columbia and became polluted following hundreds of years of development of the Eastern seaboard.

This is the year in which a “mid-point” assessment of the TMDL must be made to see whether each state is on track to meet reduction goals required by the year 2025.

Efforts to clean up the bay date back to 1983, when the states came together with nonprofit groups and the EPA to form the Chesapeake Bay Partnership.

Since then there has been some progress towards reducing pollution. For instance, nitrogen loads from municipal and industrial wastewater treatment plants have dropped from over 100 million pounds a year in 1985 to less than 50 million in 2015.

“[That’s] sixty million pounds of reductions across almost 470 wastewater treatment facilities,” Batiuk said. “We’re not done on wastewater but that is a tremendous story. That is millions of dollars of investment.”

Some of that reduction was attained locally by the Rivanna Water and Sewer Authority with the $48 million upgrade of the Moores Creek Wastewater Treatment Plant. That was paid for by ratepayers and by $21 million from Virginia’s water quality improvement fund.

Before the upgrade, the average yearly nitrogen load released into the Rivanna River between 2007 and 2010 was 506,720 pounds. That number dropped to an average of 62,958 pounds a year between 2013 and 2016, an 88 percent reduction.

“We’ve been so successful we are also earning revenue through Virginia’s nutrient exchange program,” said Teri Kent, communications manager for the RWSA. “That’s a total of $284,560 since 2013.”

Another issue with the Bay is the oxygen-free “dead zone” where aquatic life cannot survive. Batiuk said this region has reduced over time and that aquatic grasses have more than doubled since 1985.

However, Batiuk said there is a long way to go to meet the 2025 goals, and that more reductions will need to come from the agricultural sector.

Batiuk said the commonwealth of Pennsylvania has a long way to go to reduce nitrogen that flows from fertilizer spread on farms. Specifically, they must find a way to reduce nitrogen loads that reach the Susquehanna River watershed by over 30 million pounds by 2025.

“If Pennsylvania doesn’t get there, we don’t have a restored Chesapeake Bay,” Batiuk said. “They don’t have a mile of tidal shoreline but they have fifty percent of the fresh water and a large portion of the nitrogen, phosphorous and sediment in there.”

Maryland and Virginia each have to find ways to reduce their nitrogen loads by over million additional pounds a year to meet their targets.

“For them to be successful, we all need to continue to work together to be successful,” Batiuk said.

Beth McGee, senior scientist with the Chesapeake Bay Foundation, sounded less optimistic. She said that President Donald Trump’s recommended budget proposes eliminating all federal funding for the Chesapeake Bay clean-up.

“They fund the monitoring work that allows us to understand how grasses are responding and how the dead zone is responding,” McGee said. “They fund the modeling, the science and the tools that we need to continue to make progress to understand how our management actions will affect water quality and how the system will respond.”

McGee said the midpoint assessment of the TMDL also provides an opportunity to reassess the science and the tools.

“It’s not going to get any easier,” McGee said. “We’ve really gotten the low-hanging fruit. We’re going to have these new pollution targets to achieve and we also know that the challenges are going to be even steeper as we march toward 2025.”

Localities will have to come up with draft plans for how they implement the pollution targets by December 2018.

In the meantime, both Albemarle and Charlottesville have been taking steps to do their part.

Charlottesville City Council initiated a stormwater utility fee in February 2013, in part to fund ways to comply with the TMDL. So far the city has collected nearly $4.9 million from the fee.

“The utility was established to support a water resources protection program to address increasingly stringent stormwater regulations and manage the City’s water resources in an economically practicable and sustainable manner,” said Kristel Riddervold, the city’s environmental sustainability manager.

Some of the funding has gone to pay for street sweeping and to restore streams and stream banks to stop erosion.

Albemarle County has been studying whether to follow suit with its own fee.

The Board of Supervisors has not yet voted on the idea, but has dedicated 0.7 cents of the real estate property tax rate towards its own water resources management program.

The Board of Supervisors indicated last October they would support a fee but are waiting until county staff complete their plan.