On a steamy summer morning, Steve Duker perched on the banks of the Gunpowder River in Monkton and dipped a mason jar into the water.

Nearby, children and parents floated on inner tubes, laughing and splashing. But the water was the color of coffee, stirred up by an overnight storm. And that, Duker knew, likely signaled high levels of E. coli.

For four years, the Gunpowder Riverkeepers, the organization for which Duker volunteers, has been testing the waters at this and four other sites along the Gunpowder and its tributaries that are not monitored by any government agency.

The results are striking. Samples collected within 48 hours of a heavy rain frequently have E. coli levels 10 times the Environmental Protection Agency’s acceptable swimming threshold. The spot in Monkton, where hundreds gather to go tubing on summer weekends, has had high levels of E. coli five of the ten times that volunteers have tested this summer.

Few who dip their toes in the Gunpowder are aware of the threats the river faces— or its importance in the region.

The Gunpowder, dammed at Prettyboy and Loch Raven reservoirs, provides drinking water for 1.8 million people in the Baltimore region. The two branches of the waterway— Big Gunpowder Falls and Little Gunpowder Falls — wind through and around northern and eastern Baltimore County, providing valuable habitats for ecologically-sensitive animals, and places for people to boat, fish and swim — a particularly valuable resource in a county that has no public swimming pools.

Brown, rainbow and native brook trout dart through the chilly waters of the Big Gunpowder Falls in northern Baltimore County. Families swim at the Hammerman Beach section of Gunpowder Falls State Park. Fishermen toss crab pots into the tidal basin where the waters of the Big and Little Gunpowder Rivers and the Bird River flow toward the Chesapeake Bay.

Yet the Gunpowder, its scores of tributaries and the 450-square-mile watershed that surrounds them face myriad risks: sediment from development; pesticides, herbicides and fertilizers from farms, golf courses and private homes; tire dust; road salt; and warming temperatures. And of course E. coli, which signals contamination from fecal matter.

Elected officials represent residents. Lawyers and lobbyists advocate for businesses and developers. But who speaks for the natural world that sustains us?

For the Gunpowder, and 300 other bodies of water around the world, the answer is water keepers, a team of dedicated workers and volunteers who monitor, protect and advocate for the water.

Theaux Le Gardeur founded the Gunpowder Riverkeepers in 2011, modeling it on a pioneering organization formed in the 1970s to protect New York’s Hudson River.

“From forest to faucet, it’s all connected,” said Le Gardeur, 54. He has an outdoorsman’s habit of scanning the horizon when he talks. His eyes, behind wire-rimmed glasses, are the same greenish brown as the river.

Le Gardeur, a native of Louisiana who moved to northern Baltimore County in 2001 to start a fly fishing shop, Backwater Angler, can rattle off a seemingly endless series of facts about the Gunpowder, the creatures that live in and around it and the battles he has fought on behalf of the river.

“Anything we do to protect the cold, clean water in the upstream segments of the watershed goes a long way to making sure that the crabs, the shad and the rockfish and the largemouth bass in the tidal basin are protected,” Le Gardeur said.

Since its inception, the Gunpowder Riverkeepers has managed to shut down a coal plant on the banks of the lower tidal river. It’s suing a new housing development, which it says has failed myriad state erosion and sediment control inspections. The nonprofit is fighting the Maryland Department of the Environment for stricter stormwater controls and is pushing state regulators to more closely monitor a rubble landfill on the banks of Days Cove in eastern Baltimore County.

The organization has also educated thousands of residents about ways they can protect the water, from avoiding lawn fertilizer to promptly picking up pet waste.

By teaming up with law schools, pro bono legal organizations and universities, Le Gardeur has been able to stretch the budget of the nonprofit, which took in less than $115,000 in grants and cash donations last year.

The Gunpowder group is one of eight riverkeepers organizations in Maryland. The Patuxent River, the Severn River and the Baltimore Harbor are all monitored by similar groups.

Gussie Maguire, a staff scientist with the Chesapeake Bay Foundation in Maryland, said Le Gardeur and the other waterkeepers are invaluable allies in efforts to protect the bay.

“I’m trying to keep track of everything going on in Maryland all at once and I’d never be able to do it without the riverkeepers,” Maguire said. “They’re the boots on the ground. They understand what the problems are. They’re on their rivers every day.”

Testing the waters

Early on a clear morning in late July, Le Gardeur launched the riverkeepers’ boat from the Dundee Creek Marina in Middle River. Onboard was Tristan McGregor, an intern from Towson University, along with Kate Stoneman and Anna Van Dongen, interns from Chesapeake Water Watch, a project of the Smithsonian Research Institute.

Le Gardeur stopped the boat a few hundred yards from the shore so the interns could test the turbidity, or cloudiness, of the water using three different technologies: an app called Hydrocolor; a sophisticated device called a YSI that also measures pressure, pH and temperature; and the low-tech option, a black-and-white disk attached to a measuring tape.

As he piloted the boat to five other sampling spots, Le Gardeur explained some of the Gunpowder’s history. The origin of the name is uncertain, but some say Native American people mined salt peter, a mineral used to make gunpowder, from its banks, he said.

“Did you hear that?” Le Gardeur asked as a muffled boom echoed over the water. He pointed out Aberdeen Proving Ground in the distance, theorizing that workers were probably testing weapons.

Le Gardeur wound the boat under a railroad bridge as an Amtrak train rattled above, then paused by a tall wooden nest box where an osprey was tending to its fledgling.

“There’s SAV,” an intern called out, pointing to bits of plants, or Submerged Aquatic Vegetarian, in the water. Such plants, which provide food and protection from predators for fish, have become rare in this stretch of the Gunpowder due to an influx of sediment, Le Gardeur said. About 1,500 acres of underwater grass abruptly died off in the Gunpowder and the Middle River, according to a 2022 study from the Virginia Institute of Marine Science.

Near Mariner’s Point Park in Joppa, Le Gardeur cut the boat’s motor, as the water was less than two feet deep. Four hundred years ago, the water was 38 feet deep and Joppa was a bustling port, Le Gardeur said. But as the population grew, sediment disturbed by construction, deforestation and agriculture settled on the river bottom, making it impossible for large ships to pass.

‘We cannot do without nature’

Gunpowder Riverkeeper volunteers also check the water quality at five other sites along the river each Tuesday morning. While the Baltimore County Department of Health posts water quality reports for Hammerman Beach and select sites on the Gunpowder and its tributaries, many sites along the massive and complex river system are not tested.

Duker, a retired microbiologist and avid fly fisher, visits several of the locations each week, using a mason jar fastened to a long wooden pole to retrieve water samples without stirring up silt.

Duker then brings the samples to Chichedo Duru, a Morgan State University doctoral candidate in bioenvironmental science, who analyzes the amount of organic matter and bacteria, including E. coli, in the water. The results are posted on the Riverkeepers’ website and social media pages each Thursday.

An independent lab analyzed the E. coli DNA from water samples collected in 2022 and found that it stemmed from human fecal matter, not pet or wild animal waste. While it’s not clear what has caused the recent spikes in E. coli levels in the Gunpowder after heavy rains, Le Gardeur thinks it is probably coming from septic systems.

The Maryland Department of Natural Resources advises swimmers to avoid all natural bodies of water for 48 hours after a one-inch rain due to the threat of contamination. During this steamy, wet summer, it’s hard to find a day that doesn’t come within two days of a hard rain.

Swimmers should also avoid getting in water that is murky or has an unpleasant or unusual odor, DNR advises.

While E. coli most commonly causes gastrointestinal disturbances, it can also occasionally cause skin infections, meningitis or septicemia, commonly known as blood poisoning, said Dr. Karroll Cortez, an infectious disease specialist at the Greater Baltimore Medical Center in Towson.

Young children, elderly people and those with weakened immune systems are most susceptible to gastric E. coli infections, she said. People who regularly take antacids are also at higher risk because stomach acids kill pathogens, she said.

In addition to following DNR’s safe swimming guidelines, people should avoid contact with the warm still water at the edges of brackish rivers, Cortez said. Such water is more likely to play host to vibrio, another dangerous bacteria.

These pathogens are killed during the drinking water treatment process, said Jennifer Combs, a spokeswoman for the Baltimore Department of Public Works, which supervises the Prettyboy and Loch Raven reservoirs and the production of drinking water for city and county residents.

Our future drinking water flows from Prettyboy to Loch Raven to filtration plants at Lake Montebello, where the water is treated by “disinfection, coagulation, flocculation and sedimentation, sand filtration, fluoridation, and pH adjustment,” Combs said in an email.

The treated water meets or exceeds the EPA’s standards for drinking water, Combs said.

For Le Gardeur and the volunteers and students who work with him, the ultimate goal is to keep the Gunpowder clean, flowing and full of life. They hope to conduct more refined testing to determine where and how E. coli enters the river.

Duru, the Morgan State doctoral candidate, said she feels a deep sense of purpose in her work.

“I believe every human has a responsibility to keep the environment safe,” she said. “Nature can do without us, but we cannot do without nature.”