Environmentalists and local and state officials wade into the Anacostia River at Bladensburg Waterfront Park. (LAUREN GENTILE/THE HATCHER GROUP)

For the 15 or so people who took the plunge this morning, the trigger was frustration that the Chesapeake Bay ecosystem is still not in compliance with the Clean Water Act, 28 years after the deadline that all rivers should be fishable and swimmable.

The plunge, spearheaded by Howard Ernst, an author and Naval Academy teacher who writes the BayActionPlan.com blog, was a filthy affair, to judge from the photos. Within steps of the shore at Bladensburg Waterfront Park, the waders in mock-hazmat suits encountered floating garbage, smelly muck and who-knows-what toxins.

The EPA lists 90 percent of the bay as being in violation of the Clean Water Act, and health departments often issue warnings to stay out of the water for two days after heavy rain due to sewage overflowing into the river. Speakers Thursday called on federal, state and local officials to take action on storm water discharge and other measures to restore the Anacostia and other rivers leading into the Chesapeake Bay.