By now, most Alexandrians are aware of the state law passed in 2017 requiring the city to put measures in place to prevent the overflow of sewage into the Potomac River whenever it rains. Let me explain why the solution to this challenge matters to all of us.
Northern Virginia is the most vibrant region of the Commonwealth. Three of the four largest jurisdictions of the state are in Northern Virginia. This region accounted for 60 percent of the state’s population growth since 2010. And a river runs through it.
Quality of life is why so many people and businesses are moving to Northern Virginia. As Alexandrians, we enjoy a close-knit community with quick access to one of the world's great cities and to the natural beauty of the Chesapeake Bay and the Shenandoah Valley. Where else can you bicycle along the banks of "the Nation's wildest urban river" on your commute to a major metropolitan area?
Only recently have Northern Virginia communities truly realized the importance of the Potomac to their quality of life. Up until the 1950s, Alexandria dumped all of its raw sewage into the Potomac. Back then, local newspapers quipped that the Potomac was "too thick to drink, but too thin to plow.” Just 10 years ago, the Potomac Conservancy gave the Potomac a "D" grade for the health of its water.
Fortunately, public authorities have invested in improving the health of the Potomac. Pollution from sewage treatment has been markedly curtailed. One of the most obvious measures of the river's health – its fish population – is rebounding. For the first time in decades, shad have returned to the northern reaches of the Potomac. In 2017, the Potomac Conservancy upgraded the river's health to a “B" grade.
But the work of cleaning up the Potomac is far from complete. The overflow from old combined sewer systems, like Alexandria’s, continues to threaten the health of the river. During rainstorms – about 40 to 60 times a year – a mix of rainwater and raw sewage is discharged into the Potomac from four outfall locations in the oldest part of the city. Last year, the General Assembly mandated that Alexandria stop these overflows by 2025 or face significant penalties.
To address this challenge, City Council convened a committee of concerned citizens to develop a solution that meets the state's requirement with the least cost and disruption to the character of our historic city. I served on that committee. After carefully evaluating four alternatives, the committee recommended a powerful partnership between the City of Alexandria and the state-chartered utility responsible for wastewater treatment, Alexandria Renew Enterprises (AlexRenew).
By the end of June, the city will transfer ownership of the four outfalls to AlexRenew. AlexRenew will serve as the manager of the multi-year program to solve the overflow problem, including the construction of one of the largest public works in the city's history.
This involves the construction of a deep tunnel system beneath Alexandria to store combined sewer overflow until it can be conveyed and thoroughly cleaned at the AlexRenew treatment plant. The tunnel solution will result in the least disruption to the city because most of the construction activity will occur on the property of AlexRenew. Although the tunnels will extend underground along the waterfront to North Old Town and along Hooff’s Run, the millions of cubic feet of excavated soil will be hauled from the AlexRenew plant near Telegraph Road to the Beltway with minimal impact on Alexandria’s residential neighborhoods. And because the tunnels are deep beneath the surface, potential noise and vibration impacts will be minimized.
The citizen committee also found that the partnership with AlexRenew would provide the solution with the lowest utility rate impact. As one of the nation’s most advanced wastewater treatment facilities, AlexRenew already has much of the basic infrastructure in place to process the combined sewer overflow efficiently. Like any treatment plant, AlexRenew is designed to handle peak flows that occur during rainstorms. Currently, the plant converts 35 million gallons of sewage into clean water on an average day, but with some modifications it will have the capacity to handle more than double the design flows of the plant during large storm events. The committee determined that integration of the tunnels coupled with expansion and dual use of existing plant facilities would help solve the combined sewer overflow problem.
The Potomac gives Alexandria its unique character. As a natural resource at our doorstep, it contributes to the quality of life that makes our town a great place to live and a magnet for thriving businesses. The investments of the past few decades have triggered a regeneration of the Potomac. Solving the problem of combined sewer overflows is the next step in restoring a river where we can swim and fish. The partnership between the city and Alexandria Renew Enterprises will provide a solution that is both cost effective and minimally disruptive to our neighborhoods.
John Hill served on the city’s Ad Hoc CSO Stakeholder Committee from November 2017 to March 2018 and is chair of the city-appointed five-member volunteer board of directors at Alexandria Renew Enterprises.