THE BIG SPILL – Sewage Assaults the Bay

By Henry S. Parker

If 300 million gallons of raw sewage surged into Northwest Stadium (formerly FedEx Field), the toxic flood would rise to 300 feet above the playing surface – the height of a 15-story commercial building. That’s how much wastewater erupted into the Potomac River when, on Jan. 19, 2026, a 60-year-old, poorly maintained sewer pipe ruptured near Washington, DC. It took two months for emergency repairs to contain the spill – one of the largest in U.S. history. By then the sewage could be seen and smelled 30 miles downstream.

The temporary repairs kept most of the Jan. 19 discharge out of Chesapeake Bay, but the Bay is under constant assault from human waste. From Havre de Grace to Hampton Roads, chronic spills from aging municipal sewage plants and failing residential septic systems disgorge hundreds of millions of gallons of raw sewage into the estuary every year. Chesapeake Bay is in danger of becoming a giant cesspool.

Wastewater enters the Bay from households, farms, commercial facilities, roadways, and other sources. The effluent may contain solid materials; pathogens (bacteria, viruses); nutrients (especially nitrogen and phosphorus that can fuel algal blooms and cause dead zones in the Bay); toxic metals like lead and Mercury; medical waste, including pharmaceutical products; pesticides, microplastics, and a host of other noxious materials.

We know what’s needed to address this threat: rigorous, enforceable policies and advanced treatment technologies. But knowledge is not action. Successful management of wastewater is stymied by the scope of the problem and a scarcity of funding. Chesapeake Bay, the nation’s largest estuary, comprises a six-state watershed of over 64,000 square miles and is fed by more than 100,000 tributaries. Ten million people live along the Bay and its waterways. The Bay area is home to thousands of commercial establishments, schools, and factories. Farms, with their associated fertilizers, agricultural chemicals, and manure, occupy a third of Bay watershed acreage. So there’s a lot of waste to deal with. At a lot of expense.

We’re making progress on both the policy and technology fronts. Under the Clean Water Act, the EPA established Total Maximum Daily Load limits for sediments, nitrogen, and phosphorus entering the Bay, with a 2025 target date for specified pollution reduction goals. Detergents containing phosphorus have been widely banned. In 2007, Maryland enacted legislation to stem the runoff of nutrient- and sediment-laden stormwater. Maryland also created a Bay Restoration Fund (aka “Flush Fee”) to finance upgrades to the state’s 66 major wastewater treatment plants. In 2010, the Chesapeake Clean Water Blueprint established a Bay-wide framework for reducing nutrient pollution. Many farmers are following Best Management Practices to diminish pollution discharge into waterways. Sewage treatment plants increasingly use advanced technologies to strip out toxins, heavy metals, nitrogen, and phosphorus. Even homeowners are beginning to employ “best available technology” to lower nitrogen and pathogen levels in septic systems. 

Despite these measures, Bay-area jurisdictions are well behind schedule in achieving pollution reduction goals. Many treatment plants suffer from aging infrastructure. “Backyard” residential septic systems are often outdated or poorly maintained. Agricultural runoff continues to account for half the nutrient discharges into the Bay. The cost of implementing widespread advanced treatment technologies for wastewater facilities, homeowners, and farmers is currently prohibitive. Climate change also presents challenges, with larger. more frequent storms causing increased runoff and straining treatment systems. And the population of the Bay area keeps growing.

Still, there has been some success. Between 2010 and 2024, wastewater treatment plants cut nitrogen levels in half and significantly reduced phosphorus discharges. Parts of the Bay are showing improved water clarity. And growing awareness has strengthened public and private commitment to address the wastewater threat to the Bay.

For the foreseeable future the Bay area will continue to experience both large and chronic sewage spills. But we need not despair. Even as we await the required funding to significantly improve waste management systems, there is plenty we can do as individuals, starting at home. Here are a few simple suggestions:

• Periodically inspect and regularly maintain your septic system.
• Be careful about what you flush. Foreign objects can clog sewer pipes.
• Don’t pour grease down the sink; it can foul plumbing systems and sewer pipes. Instead, collect the grease, cool it, and dispose of it in a trash-bound container.
• Use strainers for shower and sink drains to prevent food scraps and hair from entering plumbing systems.
• Encourage public officials to support wise investments in waste management systems and infrastructure.
• And, finally, cherish the Bay.

Henry S. Parker is a scientist and writer who previously lived in Annapolis and now resides in Vermont.