Fred Pinkney went fishing this fall on the Anacostia River, but fish weren’t the real quarry.
One drippy morning in October, Pinkney and his helper, Tanner Stoker, seined the shallows off a sandbar near Bladensburg, MD. Then they boated downriver into the District of Columbia and put wire mesh traps in a cove near the site of a demolished Pepco power plant. They baited the traps with open tins of salmon-flavored cat food.
Pinkney, a senior biologist with the U.S. Fish & Wildlife Service, wanted the small denizens of the aquatic world that anglers would ignore, including finger-size mummichogs and banded killifish, which spend their lives in one area of the river.
But his chief target were the toxic chemicals that may have built up in the bodies of these fish during their lives in the Anacostia River. And so Pinkney’s catch was sacrificed to science — sent to a laboratory for tissue analysis.
Pinkney is specifically tracking levels of polychlorinated biphenyls, or PCBs, present in the tissue of the small forage fish. PCBs — a family of chemicals once widely used in industry and commerce — were banned in 1979 because they caused birth defects and cancer in laboratory animals and were suspected of causing cancer and other health problems in humans. Their widespread use was also linked to the decimation of eagles, osprey and other large birds of prey around the Chesapeake Bay and elsewhere.
Though their concentrations in water have diminished some since then, PCBs remain among the most insidious and persistent threats in a toxic mix of chemicals that continues to contaminate the Bay and its tributaries — including mercury, pesticides, pharmaceuticals and metals.
Eighty percent of the Bay’s tidal segments are either fully or partially impaired by toxic contaminants, according to the state-federal Chesapeake Bay Program that leads the restoration effort. PCBs figure prominently in those impairments. And PCB contamination is the basis for most of the watershed’s fish consumption advisories.
Anglers are warned in many areas of Maryland, Virginia and the District to limit or avoid eating what they catch or feeding it to pregnant women and children. The warnings include the region’s prized striped bass. And PCBs are even behind cautions in Maryland against consuming the yellow “mustard” (part of the digestive system) in steamed blue crabs.
State, federal and local officials working to restore the Chesapeake have long recognized the need to deal with toxic contaminants like PCBs because of their impacts on human health, fish and wildlife. They first pledged to reduce toxics in 1987 and have repeated that vow in each successive cleanup pact. After initially omitting any toxics commitment in drafting the 2014 Bay Watershed Agreement, officials ultimately called for states to ensure that waters are “free of effects of toxic contaminants on living resources and human health.” And for the first time, they specifically proposed to reduce PCBs.
But even so, it’s been a back-burner commitment compared to the overriding focus on reducing nutrient and sediment pollution. Toxic contaminants have struggled to gain traction, said Greg Allen, a staffer at the U.S. Environmental Protection Agency who chairs the Bay Program’s workgroup on the subject. “I have to really fight pretty hard to get commitments and visibility,” he said.
Even most environmental groups, which in the past pressed to make toxics part of the Bay cleanup, have lately made relatively little noise about it.
Beth McGee, senior water quality scientist with the Chesapeake Bay Foundation, said CBF leaders decided to focus their efforts on dealing with nutrients and sediment, which they consider to be more systemic pollutants of the Bay.
“The risk of trying to do everything is you don’t do anything very well,” she said.
But attention may be shifting. Energy has begun to gather around tackling toxic contaminants in the Bay and its rivers, with greater efforts to track down sources of PCB contamination in the Anacostia, Baltimore’s Back River and elsewhere. The U.S. Geological Survey has hosted two workshops on the issue since last year to share the latest science and reports on what other jurisdictions are doing. And Bay Program managers are looking into forming a “PCB consortium” that would share information among the states about how best to rid their waterways of these persistent contaminants.
Up the food chain, unseen
One reason toxics have drawn less attention, Allen explained, is that apart from some tumors and lesions found on fish in a few places like the Anacostia, they haven’t triggered many obvious impacts lately on fish and wildlife. Toxics once hampered the reproduction of eagles and osprey, but those effects have dissipated. And aquatic concentrations are generally low — barely detectable in places — which leads many to think they’re not a big threat.
But what you can’t see can still hurt you. Through a process called bioaccumulation, PCBs ingested by fish build up in their fatty tissues, reaching levels many times higher than what’s found in water or river sediment. As bigger fish feed on smaller fish, the PCBs build up in them, too. The same thing happens as birds and animals — and people — eat the contaminated fish.
The PCBs people may acquire from eating contaminated fish aren’t likely to cause immediate or acute health problems. But laboratory studies have found that the chronic exposure of animals to relatively low levels of PCBs can cause cancer, harm reproduction and development, and affect a variety of organs and biologic functions.
Some studies have found higher incidences of reproductive and development problems among people who’ve eaten contaminated fish. And studies of electrical component factory workers exposed to high levels of PCBs found higher incidences of cancers among them.
Within the Bay region, PCBs were once regarded as a localized problem around Baltimore, the District of Columbia and Hampton Roads, but they are now recognized as a widespread contaminant. They cling to soil, dust and sediment particles, so they’ve spread extensively through air and water. The result: They’re practically everywhere — even in the Arctic, transported far from civilization by wind.
“I can take soil from any backyard and analyze it, [and] I’ll find PCBs,” said Upal Ghosh, professor of environmental engineering at the University of Maryland-Baltimore County, who’s spent two decades researching ways to reduce aquatic contaminants.
Still, most government agencies and nonprofit groups in the Bay region have not prioritized cleaning up PCBs and other toxics.
“I’m not trying to downplay it, but in terms of big issues and bang for the buck — whether you just like a clear Bay or like oysters or rockfish — it wasn’t the number 1, 2 or 3 big issue behind overfishing, behind habitat destruction or overabundance of nutrients,” said Rich Batiuk, who retired earlier this year as associate director for science in the EPA Bay Program office in Annapolis.
“It’s been partly that it’s not an in-your-face issue,” he added. “It’s much more subtle ... and solutions are that much more difficult to do.”
As a result, it’s been up to the states to determine, river by river, creek by creek, which are impaired by which contaminant and what to do about it. For PCBs, states have produced a stack of reports setting pollution reduction targets. Some localities have even drawn up restoration plans, but relatively little has been done to get results. Officials say it’s been tough finding out where the PCBs in sediment and fish came from, and tougher still to get rid of them.
“It sort of gets second or third shrift to [reducing] nutrients and sediment,” said Erik Michelsen, head of watershed protection and restoration for Anne Arundel County, MD. “These nontraditional pollutants, frankly, haven’t gotten the attention and are harder to address.”
‘Pollution diets’ for PCBs
In the Chesapeake watershed, state and federal regulators have been at work for nearly two decades preparing local “total maximum daily loads,” or pollution reduction plans, for the various waterways impaired with PCBs. Like the Baywide TMDL — or pollution diet — for reducing nutrients and sediment, these plans rely on a combination of sampling and computer modeling to estimate the amount of PCBs getting into sediment and water. They then set a limit intended to make it safe to eat fish caught from that area. The reductions required to reach that limit are quite ambitious, exceeding 90 percent in some cases.
Virginia has drawn up TMDLs covering PCB contamination in its tributaries of the Potomac River and a few other waterways, including the Shenandoah. Others are in the works for the tidal portions of the James and Elizabeth rivers. Mountain Run, a small tributary of the Rappahannock flowing through Culpeper, is also on the to-do list.
“The whole thing’s been a learning process,” said Mark Richards, an environmental scientist with Virginia’s Department of Environmental Quality. “It’s really taken a lot of effort to get where we are today…. We didn’t have any idea, really, what we were getting into or the complexities associated with these TMDLs.”
Lee Currey, water and science director for the Maryland Department of the Environment, said that the state’s regulators have been working in earnest on PCB TMDLs since the late 1990s, but performing the water-quality monitoring needed to assess contamination has been laborious, and the science behind identifying and dealing with impairments has been evolving.
“It takes a very little bit to actually impair a water body,” he said. When Maryland regulators began the TMDL-writing process, “we just didn’t know the level of impact.”
Maryland has developed 27 TMDLs so far, the most in the watershed. But the plans take time, and state regulators say they have 21 more to do to cover all of the state’s impaired waters – including analyzing the lower Susquehanna River sediments above Conowingo Dam. They say they plan to finish all of them in the next 10 years.
In Pennsylvania, all 490 miles of the Susquehanna and its tributaries are impaired with PCBs, said Gary Walters, an environmental program manager in the state’s Department of Environmental Protection. The state has written a TMDL covering an 83-mile stretch of the river in the middle of the state — the only one completed for PCBs so far.
Plans are needed to deal with the impairments in the rest of the river, but the DEP lacks the resources and expertise to undertake something that large and complex, said Bill Brown, the department’s manager overseeing TMDL development. The DEP does plan, in the near future, to require PCB source tracking in 22 municipalities along the river segment covered by the one TMDL, he said.
“It isn’t that we’re not interested in it or not willing to focus on it,” Walters said. “We are, but there are other issues we need to keep our eye on that are more pressing in the watershed [such as] sediment and nutrients.” The state is lagging badly in meeting its sediment and nutrient reduction goals under the Baywide TMDL, which has a deadline of 2025. There are no deadlines in the cleanup agreement for dealing with toxics.
In places with PCB reduction goals, the localities bordering impaired waterways are often left figuring out how to clean them up. Most haven’t gotten much beyond the first step: trying to figure out where the PCBs are coming from.
First, they have to find them — no easy matter. Concentrations in water are often so low as to be undetectable using traditional tests. A more sensitive method can pick up ultra-low levels, but it costs hundreds of dollars more per sample.
Extra-sensitive analysis is important because the water quality criterion for PCBs set by the EPA is 64 parts per quadrillion. That’s the proverbial needle in a haystack, akin to taking a little more than 60 hairs from all the hair of all the people in the world. Miniscule though that seems, the EPA has determined that this limit is necessary to keep the lifetime risk of getting cancer from eating PCB-contaminated fish at no more than 1 in a million.
Better sampling / better solutions
Some of the PCB-tracking efforts are benefitting from a new sampling method, which proponents say promises to reliably measure PCBs at extremely low levels. It involves placing treated squares of polyethylene in the water for weeks at a time, tied to a stake or anchored with a piece of concrete. The plastic absorbs PCBs from the water and, once retrieved, the chemicals are extracted and analyzed.
UMBC’s Upal Ghosh, who has been using this “passive” sampling to map PCB levels in the Anacostia and Baltimore’s Back River, said the traditional method of analyzing water samples can yield varying results, as contamination fluctuates with weather and other factors. Passive sampling provides a good measure of PCBs in water that may be coming out of the bottom sediment, as well as gauging the concentrations that a fish might ingest through its gills.
Baltimore County officials are working with Ghosh’s laboratory to search for possible sources of the PCBs in Back River’s sediment and water.
“By checking in the water column where the [PCB] concentration is highest, we can track back upstream to see where it may be coming from,” said Wesley Schmidt, a natural resources specialist with the county’s Department of Environmental Protection and Sustainability. Schmidt said testing so far has identified one area with slightly elevated levels, but no source has been identified.
Trevor Needham, a UMBC graduate student, found that Baltimore city’s wastewater treatment plant on Back River is a surprisingly large PCB conduit, receiving about 180 grams of PCBs daily from the sewage piped into the plant.
City officials think they know where at least some of those PCBs could be coming from. While they don’t readily dissolve in water, PCBs attach themselves to fat molecules — and fats, oils and grease flushed down sinks over the years have built up in the sewer lines. Last year, workers found a congealed “fatberg” clogging a century-old pipe. Baltimore is planning to clean and line its pipe network as part of a long-
running effort to curb sewage overflows, and officials hope the effort will yield PCB reductions as well.
Meanwhile, the Back River treatment plant is removing most of the PCBs from the sewage, though about 5 grams get discharged daily into the river, the study found. Most of the PCBs removed wind up in the “biosolids,” or sludge collected during the wastewater during treatment.
Some of that sludge gets pelletized and burned in a cement factory, while the rest winds up spread on farmland as fertilizer and compost, according to Jeff Raymond, spokesman for the city’s Department of Public Works. The levels of contaminants in it are “well below the limits set by the regulators,” he said.
But those limits may not be adequate for keeping PCBs out of fish. State rules for spreading sludge on farm fields and other land are intended to guard against the polluted runoff of nutrients to nearby streams. But MDE’s Currey said the UMBC study showing PCBs in biosolids used for fertilizer may warrant reviewing those safeguards to ensure they’re adequate.
Many officials hope that measures they’re already taking to reduce nutrient and sediment runoff will yield some collateral PCB reductions. But UMBC’s Ghosh suggests it may be more effective to track down and go after PCB “hot spots.”
A couple of years ago, Anne Arundel County, MD, submitted a cleanup plan for Curtis Bay and Creek, just off Baltimore Harbor, with a number of industrial sites in the watershed. The plan called for curtailing PCBs by installing stormwater management practices, paired with regular street sweeping and storm drain clean-outs.
But the projected price tag ranged from $23 million to $34 million. Michelsen, Anne Arundel’s watershed restoration chief, said he’s since asked state regulators for more time to consider whether there might be other sources of PCBs that would be easier to remove and cost less.
“Rather than launch full-fledged into a strategy of trying to scrape a small amount of PCBs out of stormwater practices,” he said, “why don’t we spend a little additional time investigating where the hot spots are?” He noted that earlier this year, the Coast Guard reported uncovering a previously unknown cache of construction debris and toxic chemicals, including PCBs, in its Curtis Bay shipyard.
The Anacostia: Help wanted
The Anacostia, which flows from suburban Maryland into the District before meeting the Potomac, may pose one of the most complex challenges for cleanup. Besides harboring PCBs, the river’s sediment is tainted with a variety of pollutants harmful to humans and wildlife, including lead, pesticides and polycyclic aromatic hydrocarbons (PAHs), a byproduct of burning fossil fuels, wood and garbage that is also linked to cancer.
Gretchen Mikeska, Anacostia restoration coordinator for the District’s Department of Energy and Environment, said the city expects to settle on cleanup goals soon. But success will depend on working with partners, including the National Park Service, which owns the river bottom and parkland along the lower river.
The cleanup will also require help from upriver in Maryland, where the bulk of the Anacostia’s watershed lies. Studies by Ghosh’s laboratory have tentatively identified three of the river’s nine tributaries, most notably Lower Beaverdam Creek in Prince George’s County, as significant sources of PCBs.
Unless land-based sources of PCBs can be identified, the options for dealing with PCB contamination in the river bed are fairly limited, Mikeska said. They are: excavate contaminated sediments and haul them away for incineration or disposal in a safe landfill; bury them under a cap of relatively clean sediment; try to treat the PCBs where they are; or “wait for things to get better.”
By collecting stay-at-home minnows this fall from 15 different spots along the river as well as in the Potomac, the Fish & Wildlife Service’s Pinkney hopes to help the District pin down sources of PCBs that can be cleaned up.
“The good news is the river’s not as contaminated as we thought,” said Jim Foster, president and CEO of the Anacostia Watershed Society, which has pressed for a toxics cleanup there. PCB levels in the river are a fraction of what’s been measured in other, more industrialized rivers, like New York’s Hudson. And there’s been a marked decline since the 1990s in skin and liver tumors found in brown bullhead catfish in the Anacostia, according to Pinkney. While those are caused by PAHs, research indicates that PCBs may contribute to their growth and spread.
Mikeska said she believes stream restorations that the District has undertaken for other reasons have helped. But much more is needed.
“The long-term goal is to have no fish advisories,” she said. Given the uncertainties and complexities involved, she said, “It’s almost impossible to say when that would be the case.”
It might not have to take decades. UMBC’s Ghosh and a colleague, microbiologist Kevin Sowers in UMBC’s Department of Marine Biotechnology, have teamed up to develop a pair of methods for treating and immobilizing the PCBs, which could speed up the process.
Ghosh has developed a form of activated carbon, called SediMite, that has successfully “locked up” PCBs in wetlands and sediments. When spread on the bottom, the carbon captures PCBs in bottom sediment that otherwise might dissolve back into the water.
Sowers has come up with a companion treatment, using naturally occurring bacteria to accelerate the breakdown of PCBs in aquatic settings. By infusing tainted sediment with bacteria mass-produced in bioreactors, Sowers said he’s been able to significantly reduce PCB levels in months. His first tests used bacteria from Baltimore Harbor, he said, but he’s since found an even more-potent strain in Charleston, SC.
Working with Ghosh, he’s treated activated carbon pellets with the bacteria to ensure they’ll stay in place, so that PCBs are not only immobilized but degraded more rapidly than would occur otherwise.
“It’s the best of both worlds,” Sowers said. Where natural degradation could take decades, seeding contaminated sediments with large quantities of the bacteria can break down 80–85 percent of the PCBs, he said, while the rest remain bound up in the activated carbon, unable to dissolve into the water.
The scientists’ use of bacteria-laden activated carbon has proven effective at treating PCB-contaminated sediments in relatively small, confined ecosystems such as ponds, lakes and wetlands. It hasn’t been tried on a broader scale, particularly in more dynamic water bodies affected by currents or tidal sloshes.
“The challenge is, if you can get money to clean up hot spots, will it help fish?” Ghosh said.
The answer, if you look at the Delaware River basin, appears to be yes.
Progress in Delaware
Beginning around 2000, the Delaware River Basin Commission launched a campaign to address toxic contaminants. It persuaded major wastewater plants and industries to test their discharges for PCBs. They used the more sensitive, expensive test to spot PCBs and found that the top 10 dischargers accounted for 90 percent of all of the contaminants getting into the river from point-source outfalls; runoff was the second biggest source.
Greg Cavallo, a senior geologist with the commission who worked on the effort, said factories and treatment plants undertook a variety of actions to get PCBs out of their waste stream, including cleaning and removing PCB-laden sediment from discharge pipes and storm drains. They also revisited past cleanup sites, because the PCB levels that were acceptable for those projects may not be keeping the contaminants out of the water.
“Everybody did something different,” he said, but it involved “a lot of detail. We sweated it out.”
The results so far have been impressive. Between 2005 and 2016, the flow of PCBs into the river from the top 10 dischargers declined 76 percent, Cavallo said.
As a result of declining contamination levels in fish tissues, warnings about eating fish from the river eased somewhat.
More is needed, Cavallo said, but the Delaware basin’s experience attests to the value of taking concerted action, with the commission as the conductor.
“It’s more difficult to implement something like this across all jurisdictions without someone taking the lead,” he said. “When there was a meeting, there was one voice, one goal. That helped in getting the message across.”
Action in the Bay region
With the hope of spurring a similar stepped-up effort in the Chesapeake watershed, state officials have authorized the EPA’s Chesapeake Bay Program staff over the next year to explore the feasibility of forming a “PCB consortium.” It would not have any authority over states, but would share information and promote the best methods for identifying and remediating sources of the chemicals.
The EPA’s Greg Allen said the consortium would be “bringing everybody together to say, ‘how can we work together to address the problem as efficiently as we can?’”
The consortium idea, though, is on the back burner for the next several months, at least. State officials specified that the feasibility study wait until they finish updating nutrient and sediment pollution reduction plans, due in April.
Nonetheless, Allen and others say it’s time to get serious about tackling PCBs and other toxic contaminants.
“Can we do just nutrients and have a restored Bay? Absolutely not,” Allen said. A cancer survivor himself, he expresses a certain passion about it.
“The residents and visitors of this watershed every day have the potential to be consuming these toxic pollutants that in the case of PCBs add to our carcinogenic risk,” he added. “That’s happening every day, all across this watershed. We shouldn’t be tolerant of that.”