Keeping it Clean

On any given summer weekend, Conquest Beach on the upper Eastern Shore’s Chester River undergoes an invasion of sorts. Typically occupied by residents like bald eagles, turtles, and racoons, the beach and its shallow waters are transformed into a floating Margaritaville by scores of boaters who anchor there.

The popular spot is a scenic place to hang out, swim, sunbathe, fish, water ski, and tube. It’s also a great example of why the Chester River and its tributaries in 2021 became Maryland’s newest No Discharge Zone (NDZ), after five years of persistent effort by water quality advocates and others who worked with the Maryland Department of Natural Resources (DNR) to successfully apply to the Environmental Protection Agency (EPA) for the designation.

“This is all about keeping boat waste out of the water,” says Isabel Hardesty, executive director of ShoreRivers, one of the organizations that developed the application. “Having a no discharge zone is just one strategy to doing that. Even though our land use is 65% row-crop agriculture and we have a huge agriculture and restoration department working with landowners [to reduce polluted runoff], that doesn’t mean we shouldn’t work on all the other sources of pollution as well.”

The Chester River and its tributaries joined Maryland’s other NDZs—northern portions of the Maryland Coastal Bays, including the tidal waters of Ocean City Inlet, Sinepuxent Bay, Isle of Wight Bay, Assawoman Bay, and their tributaries, and Herring Bay on the western shore near Deal, all established in 2001. This summer, 13 waterbodies in Anne Arundel County are slated to become the newest NDZ in state waters—Stoney Creek, Rock Creek, Bodkin Creek, the Atlantic Marina Resort (south shore Patapsco River), Magothy and Little Magothy rivers, Severn River, South River, West and Rhode rivers, Podickory Creek, Sandy Point/Mezick ponds, Whitehall Bay, Oyster Cove, and Fishing Creek.

Simply put, a No Discharge Zone is a body of water where boats may not dump any sewage overboard. For those who aren’t boaters, this may seem self-evident, but as recently as 30 years ago, it wasn’t uncommon for boat toilets (known as marine heads or marine sanitation devices, MSDs) to pump their contents directly into the water, much like cities once dumped their raw, untreated sewage. Today, federal law prohibits boats from discharging raw or insufficiently treated sewage within three nautical miles of shore; properly treated sewage may be discharged within three nautical miles.

No boats may discharge any sewage—treated or not—within an NDZ.

Under the Clean Water Act, the US Coast Guard (USCG) and EPA regulate MSDs on boats; the EPA sets standards for effluent levels, and the USCG certifies and regulates the three types of marine heads. Two of them—Types I and II—use a variety of chemical and other methods such as maceration to pre-treat sewage onboard, meeting federal standards for fecal coliform bacteria, and then release the treated effluent. Type III MSDs hold sewage onboard and prevent it from ever being released; this can be via a holding tank, a portable toilet, or even a composting toilet.

Boats with Type III MSDs typically get rid of their sewage at a marina’s pump out station or into a local pump out boat. Those with Types I and II can do the same, or they can discharge their treated waste, as long as they’re not in an NDZ.

Scores of NDZs are located throughout the country, among them all waters in Vermont, including Lake Champlain, all New Hampshire coastal waters, much of the Great Lakes, Washington’s Puget Sound, and state waters within the Florida Keys National Marine Sanctuary.

In addition to Maryland’s designated zones, in Virginia’s portion of the Chesapeake Bay, Lynnhaven River, Broad and Jackson creeks, and Fishing Bay are also NDZs.

Proponents of these zones cite two primary reasons they’re needed: to keep shellfish beds and humans safe from fecal bacteria that can make them sick, and to improve water quality by helping reduce the amount nutrients entering the water.

Boaters like to find quiet places, safe from wind and waves, to anchor to spend the night or raft up with friends, and the Chesapeake Bay is renowned among sailors for its sheltered coves and creeks. Most marinas, as well, are located in protected areas. But the same qualities that make a great anchorage have a downside when it comes to sewage if a boat’s MSD is not working properly, or if boaters are pumping raw sewage overboard.

On Labor Day weekend of 1978, Maria A. Faust of the Smithsonian’s Chesapeake Bay Center for Environmental Studies in Edgewater, Maryland, (now known as the Smithsonian Environmental Research Center, or SERC), examined fecal coliform levels in a popular anchorage next to SERC’s location on the Rhode River.

In her paper, published in 1982 in The Science of Total Environment, she described sampling at six locations at 10 a.m. and 3 p.m., from Friday afternoon until Tuesday morning. She found that “concentrations of bacteria increased from 3 to 26 FC [fecal coliform] cells/100ml and from 7 to 68 FS [streptococci]/100 ml soon after the arrival of the boats, persisted during the weekend, and decreased soon after the boats departed the area.”

She also noted, however, that compared with land-based sources of fecal coliform pollution monitored in the river at that time, “the relative contribution of boating to FC pollution is usually low due to due the large numbers of FC introduced by runoff.”

An October 2010 EPA and NOAA report, “Environmental Assessment of the Marine Sanitation Device Discharge Regulations for the Florida Keys National Marine Sanctuary,” noted that, “A fecal bacteria associated with the human gut and likely transported through sewage has also been causally linked to white pox disease, which has caused significant losses of shallow-water Caribbean elkhorn coral within the FKNMS…While sewage discharge from vessels may be a relatively minor contributor to the total pollutant load affecting the sanctuary, vessels frequently congregate near areas, such as shallow reefs, that may be particularly vulnerable to such localized loading.”

Even in more open areas, tidal flow can only do so much to disperse discharges. In February 2010, the coastal waters around the barrier island community of Wrightsville Beach, North Carolina, became an NDZ after two years of research into fecal bacteria contamination in the waters surrounding the town and its marinas. According to a paper published in July 2010 in the Journal of Environmental Management, the research included sampling for fecal coliform and Enterococcus—a type of bacteria found in intestinal tracts that can cause infections in humans. The researchers noted that it “is longer-lasting in the marine environment and as others have determined…is a more appropriate marine indicator due to fecal coliform salinity sensitivity.

“Of the 96 samples collected from nine locations during the study, the water contact standard for Enterococcus was exceeded on 13 occasions…A lack of sewer leaks and lack of septic systems in the town pointed toward discharge from boat heads into the marine waters as the major cause of fecal contamination; this was supported by dye studies,” the researchers said.

Along with sampling for bacteria, researchers introduced dyes into the water to better understand current flow in their study areas. In one area, a green dye moved rapidly down the main channel, but tendrils spun off and slowed near shore, even forming eddies around dock pilings.

“Thus, fecal bacteria sourced from boat heads located well up-channel could readily become entrained around dock structures down channel, and settle to the sediments where they could later be released to overlying waters by boat docking activities or human and animal waders,” the researchers said. 

Marine toilets that treat sewage remove fecal coliform bacteria but not nitrogen or phosphorous, and concerns about those inputs, especially in enclosed waterways with limited tidal flushing, has been noted by Maryland DNR and others.

But accurately quantifying nutrient input from recreational boats specifically is difficult. One attempt to do so was a 2018 report of the Chesapeake Bay Program’s Boat Pump-Out BMP Expert Review Panel, tasked with developing a report that “evaluates, defines, and configures the proposed Boat Pump-Out Facility in a No Discharge Zone BMP for nutrient reduction credit within the Chesapeake Bay Program’s Phase 6.0 Watershed Model.”

The group developed a model for estimating nitrogen from recreational boat waste based on several factors including the number of boats, type of boat (power or sail), how many days per year boats are used, how long such trips lasted, how many people were aboard, and the nutrient output per person per day. Their findings, modeled between 1985 to 2015, estimated a low of about 26 tons of nitrogen in 1985 to a high in 1999 of nearly 35 tons contributed annually by boats in Maryland waters in Chesapeake Bay.

“This was the best estimate the expert panel could put out, and there hasn’t been any revisiting since this,” says Lewis Linker, the Chesapeake Bay Modeling coordinator for the EPA’s Chesapeake Bay Program Office. He adds that nutrient reduction from NDZs is really a co-benefit to the primary benefit of health and safety for shellfish beds and recreational water use through eliminating inputs of human gut bacteria.

“The loads of nitrogen from recreational boat discharges are relatively small compared to other sources of wastewater nitrogen delivered to tidal waters,” Linker says. “Nitrogen loads from recreational boat discharges into tidal waters are only 0.7 percent of septic nitrogen loads delivered to the Bay and 0.3 percent of wastewater plus combined sewer overflow loads to the Bay.

Under the Clean Water Act, a state can apply to the EPA to designate an NDZ. In Maryland, local stakeholders (groups like ShoreRivers, for instance) do the extensive legwork to complete that application, including holding public meetings and gathering data on environmental factors as well as boating and pump out statistics, says Donna Morrow, program manager of DNR’s Chesapeake and Coastal Service Department, who pilots NDZ applications through the process. Once the application’s requirements are met, the DNR submits it to the EPA, where it makes its way through the federal register process.

A successful application has two primary drivers: showing that the waters require additional environmental protection and that there are enough pump out facilities in the proposed zone to meet the boating demand.

For Anne Arundel County, the application noted that “the Magothy River, White Hall Bay/Meredith River, Severn River, South River, Rhode River and West River have been listed on current or previous Clean Water Act 303(d) lists of impaired waters by Maryland as impaired for shellfish harvesting due to fecal coliform. As such, many shellfish beds are restricted or closed. All except White Hall Bay/Meredith Creek are also impaired for nutrients (nitrogen and phosphorus) and all except the White Hall Bay/Meredith Creek and West River for total suspended solids (TSS).”

No matter how fragile the waterway is, pump out station availability is a critical corollary requirement. Since 1992, the Clean Vessel Act has allowed the US Fish and Wildlife Service (USFWS) to award competitive grants to states to build pump out stations. Marinas can apply to the DNR to have a pump out station installed; federal money—via the Sportfish Restoration and Boating Trust Fund, built through sources including taxes on fishing equipment and fuel attributable to motor boats—pays for 75%, and the state supplies the remaining 25% from the Waterway Improvement Fund, supported by the 5% excise tax that boaters pay when they purchase a boat in Maryland.

In Maryland, more than  350 grant-funded pump out stations  (mostly at marinas) and three pump out vessels are operating, says Celeste Anderson, the Clean Vessel Act program administrator within DNR’s Chesapeake and Coastal Service.

The DNR estimates the land-based pump outs and boats remove “roughly two million gallons of vessel sewage annually.” Land-based stations typically charge $5 for the first 50 gallons of sewage pumped.

Maryland’s three pump out boats are operated by the City of Annapolis (Severn River), ShoreRivers (Wye and Miles rivers), and Arundel Rivers Federation (West and Rhode rivers). 

In those areas, boaters can call the vessel via VHF, phone, or text and request a pump out. This is especially useful in a waterway like Wye River, which has no landside pump out stations. Fees are variable—the ShoreRivers boat is free, while the Annapolis boat charges $5 per tank up to 50 gallons.

“Over the past two years, (the average length of our federal grant), we spent approximately $365,000 (75% federal funds/ 25% state funds) on the purchase and installation of new pump out units at marinas who applied for grant funding,” Anderson noted in an email. “Also in this two-year period, we spent roughly $522,000 (75% federal funds/ 25% state funds) reimbursing marinas for the operation and maintenance expenses associated with maintaining a pump out that is accessible to recreational boaters. Included in this cost are the operation and maintenance expenses for running the three pump out boats.”

Most new boats are manufactured with holding tanks installed, making it easy for boat owners to abide by the rules in an NDZ, Hardesty says. Owners of older boats must find ways to retrofit their vessels to be in compliance, but innovations like compact, easily installed composting toilets are helping change the game.

“We push our strategies to do what the science tells us,” she says. In the case of NDZs, even if boat waste is a seasonal issue that isn’t a major overall contributor to the Chester River’s water quality problems, local hotspots like Conquest Beach require extra attention. And, while the Chester’s NDZ was “science-based, it just felt like the right thing to do,” Hardesty says. “Everyone can do something. Boaters can do this.”