Falls Church, like every jurisdiction in Virginia, is now facing a new state / federal mandate aimed at restoring the Chesapeake Bay called the Chesapeake Bay Total Maximum Daily Load (TMDL). A TMDL is also commonly referred to as a pollution diet. In this case, the Chesapeake Bay TMDL sets a limit on the amount of phosphorus, nitrogen, and sediment (measured in pounds) that enters our streams on an annual basis.
In 2012, the City was given numerical targets it must achieve by 2025 with specific milestones along the way.
In order to comply with the Chesapeake Bay TMDL the City will need to build new water quality facilities, such as rain gardens, infiltration trenches, underground storage with filters, and hydrodynamic separators. Redevelopment of private property will assist in reaching our goals, however, City staff estimates those efforts will constitute no more than 5% of the pollution that must be removed.
The remaining 95% will need to be removed by the City on public property. The Department of Public Works will look for ways to save in construction costs by combining stormwater capacity projects with quality facilities where feasible. City staff estimates compliance with the Chesapeake Bay TMDL will require $15 million in expenditures by 2025 for stormwater quality specific construction projects.
The state and federal regulatory environment has become increasingly restrictive over the years. During the 1970s and 1980s regulations focused primarily on flood control and drainage issues. In the late 1980s and 1990s the focus shifted to water quality and protecting the Chesapeake Bay from impacts of new development.
Today, with previous Chesapeake Bay restoration efforts falling short, there is increased pressure to retrofit existing communities and to treat high volumes of stormwater runoff as a pollutant.