As the region’s sewage plant, the Blue Plains Advanced Wastewater Treatment Plant being at risk for flooding is no joke.
In the words of the November 2016 Climate Ready DC plan, the District is experiencing increasingly severe weather from “record-breaking heat waves and snowstorms” to “flooding caused by rising sea levels and heavy rains.” The plan cites federal government data showing that the Potomac and Anacostia rivers have both risen 11 inches in the past 90 years, causing an increase in riverfront flooding of more than 300 percent. By 2080, the U.S. Army Corps of Engineers predicts another 3.4 feet of sea-level rise. Meanwhile, a precipitation event that has a one in 100 chance of happening this year is expected to happen once every 15 years by the 2080s.
“A flood to Blue Plains could temporarily impact our ability to treat wastewater,” says Maureen Holman, a lawyer with an environmental background and the executive vice president of administration at DC Water. Drinking water would not be affected.
Until wastewater treatment came back online, millions of gallons of overflow would go into the Potomac, Holman says. “There would be serious impacts to the Potomac, downstream neighbors, and the Chesapeake Bay.” The duration would depend on what was impacted. “After Sandy, it took months for [wastewater treatment plants] to recover,” she adds. “But they were fully inundated.”
As D.C. faces an array of dangers related to climate change, how is Blue Plains responding? Experts say DC Water, which operates Blue Plains, has become a forward-thinking leader in both adaptation and mitigation—adapting its facilities to the new reality and reducing its emissions of greenhouse gases.
The facility, the largest of its kind in the world, sits on 153 acres at the District’s lowest point, along the Potomac in Southwest D.C. Opened in 1937, Blue Plains now averages 384 million treated gallons of wastewater per day, with more than 1 billion gallons per day at peak wet weather capacity. DC Water distributes drinking water to the District and collects and treats wastewater—from using the toilet, taking a shower, or washing food or dishes—for more than 2 million people in the District, Montgomery and Prince George’s counties in Maryland, and Fairfax and Loudoun counties in Virginia.
As the climate changes, Blue Plains will be most impacted by projected sea-level rise and increased storm surge from hurricanes and nor’easters, even as more frequent rain also will bring more flow into treatment for processing. “Our primary concern is our proximity to the river,” Holman says, “which is why we have prioritized hardening Blue Plains and some of our other facilities, whenever possible.” Hardening is the process of making physical changes to infrastructure to protect it from climate-related damage.
The challenges faced by Blue Plains “are even worse than just a 500-year flood coming down the Potomac River,” emphasizes Rachael Jonassen, Ph.D., the director of climate change programs in the Environmental and Energy Management Institute at the George Washington University. “They’ve got to worry about storm surge from more intense hurricanes coming up the Chesapeake [Bay] and affecting areas here.”
A partially constructed sea wall will provide a hard barrier between Blue Plains and flooding from the Potomac, protecting billions of dollars of infrastructure and treatment capabilities. It will be a minimum of 17.2 feet high around Blue Plains, equal to the 14.2 feet reached by a possible Category 3 storm or what used to be known as a 500-year flood, plus 3 extra feet of freeboard. It’s mostly concrete, though the height and materials vary, Holman explains. On a recent visit to Blue Plains, accompanied by DC Water spokesperson Vincent Morris, I saw a thick concrete barrier topped with rusted steel.
“DC Water already had the beginning of our sea wall planned for, based on our own assessments, but the urgency has increased based on recent events,” Holman says. “Superstorm Sandy and the severe impacts to wastewater plants in New Jersey and New York were certainly a stark and shocking reminder of the potential impacts of these storms and the needs to protect our infrastructure from what is coming in the future.”
The flood wall is among the projects and plans under way to harden DC Water facilities against climate change impacts, according to an Aug. 8 summary document that Holman provided. Substantial completion of construction of the flood wall—with an estimated total cost of $4 million, and partially funded by a Federal Emergency Management Agency (FEMA) grant with a maximum federal share of $2.4 million—is expected in May 2021. Construction on the final segments of the flood wall is expected to start in 2024.
“FEMA provides 75 percent in a grant that must be matched 25 percent with DC Water rate-payer dollars” in water bills, Holman says. “I am unsure what the current estimates are, but the goal is to have little or no impact on the rate payers and do the work in conjunction with other Blue Plains construction projects wherever possible.”
Two other projects include flood protection for both the Main Pumping Station on O Street SE, built in the early 1900s on the Anacostia River near what is now Nationals Park, and the 14th Street Bridge Pumping Station, which pumps stormwater from the I-395 underpasses at East Potomac Park. The pump station projects—with anticipated total costs of approximately $1 million and $1.75 million respectively, and 75 percent funded by the FEMA grant—are scheduled to be completed by October 2019.
Because wastewater facilities generally end up at a region’s lowest point so that sewage or stormwater can rely on gravity to flow downhill, being prone to flooding is “a fairly common problem,” says Barry Liner, a civil and environmental engineering Ph.D. and the chief technical officer at The Water Environment Federation. According to the U.S. Environmental Protection Agency website, Blue Plains decided to build a sea wall to protect it against flooding rather than moving the facility to higher ground. “You don’t just move the world’s largest advanced treatment plant up 500 feet. That’s not happening,” Liner says.
According to Holman, the tripling in the coming decades of days exceeding a 95-degree heat index, as projected in the Climate Ready DC plan, is a general concern across DC Water operations. As temperatures rise, Jonassen explains, trees, plants, and animals that used to thrive in cooler climates die off or are less successful, while other species adapted to warmer climates move in, including diseases. Increased heat also stresses the human body, and people who work outside are at the greatest risk.
In the area of mitigating climate change, DC Water’s efforts are significant, Liner says. One is renewable energy. Unveiled in 2015, a combined heat-and-power plant at Blue Plains turns the region’s sewage into energy, and it now generates one-third of Blue Plains’ energy needs. A new solar project continues to reduce Blue Plains’ reliance on fossil fuels, Holman says. Meanwhile, the ongoing Clean Rivers Project, including the proposed Potomac River Tunnel Project, is designed to capture and clean wastewater from combined sewer overflows during rainfalls, before they reach the rivers. Liner also mentions DC Water’s investment in green infrastructure and a specially trained workforce. The ribbon-cutting for its new environmentally friendly administrative building above the O Street Pumping Station took place in May, though staff moved in late last year.
Just 20 years ago, DC Water was “actually very poorly thought of, and now they are one of the most innovative utilities in the world,” Liner says. “They’re trying to do what’s in the best interest of their rate payers and also what’s in the best interest of the environment.”
Jonassen has visited Blue Plains and spoken to staff there about responding to climate change. “They’re a real leader in this,” she says. “They should be very proud of what they’re able to accomplish.”
At the same time, she thinks of all the other places in D.C. along the same waterfront, such as Reagan National Airport, that should be preparing for climate change, but need to get funding—a lot of it coming from the federal government. “And it’s just not been there because of the priorities that are being set,” she says.
On September 23, the United Nations will convene an emergency summit on climate action in New York “to meet the goals of the Paris Agreement and to galvanize action that can limit climate change to 2 degrees Celsius and even 1.5 degrees Celsius as science now asks.” The U.N. is calling on the world’s governments to provide plans to enhance their nationally defined contributions by 2020 to reduce greenhouse gas emissions by 45 percent over the next decade and net zero emissions by 2050. On September 20 and 27, global climate strikes are planned, led by Swedish youth climate activist Greta Thunberg, who was just in D.C. for nearly a week after sailing across the Atlantic Ocean. Numerous news outlets around the world have committed to running climate coverage in the week leading up to the U.N. climate action summit.
“Those who are concerned about this are very much interested in helping governments around the world see the threat that lies ahead of us and try to prepare,” Jonassen says. “If we don’t prepare, our economies globally are going to suffer. Our ability to operate as societies will suffer.”
Liner observes that Miami sometimes has flooding on dry-weather days now because of sea-level rise. “The fact that DC Water’s already doing this is good,” he adds. “They’re not waiting until too late, you know.”