A train crash, a power plant discharge, an underwater pipeline rupture — or an act of terrorism — could cripple the drinking water supply of the nation’s capital. And there’s no Plan B.
D.C. and its Maryland and Virginia suburbs are dependent on the Potomac River as the main — or sole — source of drinking water.
“We might have plenty of water upstream that can replenish the Potomac River during drought, but what happens if there’s contamination, and you can’t draw water from the Potomac River?” said Rudy Chow, general manager of the Washington Aqueduct, which is operated by the U.S. Army Corps of Engineers.
The Potomac River is the sole water supply for the District, Arlington County and the City of Falls Church and the primary water supply for two other local water utilities.
“It is a vulnerability that we are facing,” said Chow.
WSSC Water, which serves most of Montgomery and Prince George’s counties, draws 30 percent of the water it sends to customers from the Patuxent River. Fairfax Water, which serves Fairfax and Prince William counties, gets a portion of its water from the Occoquan Reservoir.
D.C. Del. Eleanor Holmes Norton said the House’s Water Resources Development Act of 2022, which passed out of committee Wednesday, aims to provide more resiliency. “There is an urgent need for Congress to act to protect the drinking water and other infrastructure of the nation’s capital from serious vulnerabilities,” Norton said in a statement.
If passed in the House, the bill would authorize the U.S. Army Corps of Engineers to undertake an engineering and feasibility study to consider backup water supplies. Currently, the study is not included in the Senate’s WRDA.
“There are some short-term measures that we ought to be focusing on now,” said Chow, “like an early alert warning system, if there’s some sort of contamination or spill upstream.”
Currently, the Interstate Commission on the Potomac River Basin has a flow simulation tool in place to forecast leading and lagging edges of any contaminants, so they can adjust operations as needed.
In addition, the ICPRB and local utilities, suppliers, and emergency response agencies, have an internal e-alert system to address spills within the Potomac River Basin.
One (expensive) option
As WTOP first reported in 2016, local water officials have been studying the possibility of utilizing the Travilah Quarry, on Piney Meetinghouse Road in Rockville, Maryland, to provide water storage for D.C., Maryland and Virginia water utilities in the event that water from the Potomac River would become unavailable or undrinkable.
“A quarry is a good option — we’ve got to make sure it’s the right option for the D.C. area,” said Chow.
The cost of transforming Travilah Quarry — which provided crushed stone to build the Intercounty Connector and widen Interstate 270 — would be enormous, said Chow.
First, he said, the quarry would have to be bought. “Then you have to think of the pipeline you’d have to build; real estate would be costly as well, to find a path that’s viable to send and receive water,” said Chow. “Obviously, this area is well built-out — it’s not like an open space where we can just lay the pipe down and go.”
If the Army Corps is given the go-ahead — and the money — to do the engineering and feasibility study to consider backup water supplies, Chow believes there are some less-costly options than a quarry.
“We have about 24 to 36 hours storage,” currently, Chow said. “Can we increase underground storage facilities, tanks, to increase that capacity? That is something that needs to be looked at.”
Other options might be reclaiming Potomac Water. “Can we recycle some of the water for drinking water purposes? Obviously, places in the west, including California are already either doing direct or indirect potable reuse.”
‘It’s a big investment’
The challenge of building resilience into the drinking water supply of the nation’s capital is financially daunting, jurisdictionally demanding, time-consuming — yet crucial.
“The Corps is committed to protect our water supply, our water sources, and we are always mindful of the vulnerabilities, and security risks that are involved,” said Chow.
Given the ever-present risk to the nation’s infrastructure, Chow said, short-term improvements should be implemented at the same time as a long-term solution is sought.
“This is a lot of money, and we want to do it right,” said Chow. “We don’t want to sink billions of dollars only to find out ‘Hmm; it doesn’t work like we thought.'”
“It would basically be 10-plus years in terms of planning, design, construction, and implementation of it,” said Chow. “So in the meantime, we need to deal with the vulnerability that we are facing.”