Only 10 of the 300 sewage treatment plants that dump waste into the Chesapeake Bay are using the right equipment to remove nitrogen because the plants are outdated and regulators fail to require upgrades, according to a report released yesterday.
The Chesapeake Bay Foundation says that regulatory officials are not enforcing Clean Water Act provisions that require sewer plant upgrades when plants discharge nitrogen and other pollutants into an "impaired" waterway such as the bay.
"Nitrogen is the single most significant source of pollution in the bay. It's not being stopped and it's time to enforce the law and stop it. It's as simple as that," said William C. Baker, president of the Chesapeake Bay Foundation.
Federal, state and city officials said the report -- based on 2002 sewer plant discharge records -- fails to account for recent upgrades, planned upgrades and the size and age of some of the area's largest sewage treatment plants. The report also uses as a model nitrogen reduction technology that only became available in the past few years.
"What we'd like to see is some recognition that that there has been significant progress," said Richard Batiuk, associate director for science in the Environmental Protection Agency's Chesapeake Bay Program office.
He said that despite population growth, sewer plant improvements have cut nitrogen and other nutrient pollution by 32 percent since 1985.
State officials said most of Maryland's 66 major sewage treatment plants -- responsible for 95 percent of the effluent being discharged into the state's portion of the bay -- have either been upgraded or are about to be upgraded.
Baltimore officials say they've made more than $500 million in upgrades at the Patapsco and Back River treatment plants in the past decade and will spend $200 million to reduce nitrogen at the Patapsco plant by 2010.
"We haven't had a chance to look through this whole report, but we're pretty comfortable with what we're doing," said Kurt Kocher, a spokesman for the Baltimore City Department of Public Works, which operates both plants.
Nitrogen is the bay's chief pollutant and sewer plants are its second largest source, contributing about 20 percent of what flows into the bay. Agriculture contributes another 41 percent.
Baker said nitrogen helps create dead zones in the bay, areas unable to support aquatic life because of a lack of oxygen. Nitrogen and other nutrient runoff fuel algae blooms, which block sunlight and kill underwater vegetation that would otherwise produce oxygen. When the algae die and decompose, bacteria feed on them and deplete oxygen, creating the zones.
The report says that Maryland dumps 8.4 million pounds of nitrogen in the bay each year, compared with 22 million pounds from Virginia.
But the report says the six states in the bay watershed, along with the District of Columbia, need to improve sewage treatment plants so they reduce nitrogen discharge by 39 million pounds each year. A bay task force in November last year put the cost of the improvements in the watershed at between $2.7 billion and $4.4 billion.