The governors of the six Chesapeake Bay states, the mayor of Washington, D.C., and the chair of the Chesapeake Bay Commission have submitted a letter to the U.S. Congress to include in the reauthorized Federal Surface Transportation Act a policy to reduce polluted stormwater runoff from federal highway construction and reconstruction projects.
Nationwide, roads and related infrastructure make up at least two-thirds of all paved, impervious surfaces, according to the letter. These areas promote runoff because they do not allow water to naturally soak into the ground. When it rains, pollutants from tailpipe emissions, fluid leaks, break linings and tire wear are picked up in runoff and carried to the nearest sewer or waterway.
The letter points to a 2002 study in Maryland that showed highways in the state accounted for 22 percent of nitrogen and 32 percent of phosphorus coming from urban areas. The study showed that highways and mobile sources annually contribute 36 million pounds of nitrogen that pollute Maryland’s land, air and water. By comparison, wastewater treatment plants contribute 17 million pounds of nitrogen per year.
Most federally funded highways were constructed without the stormwater runoff controls needed to protect the health of local streams, creeks and rivers. As a result, 66 percent of the waterways listed on the national Clean Water Act 303(d) list of impaired waters are polluted because of highway runoff.
Today, the green infrastructure techniques that relieve these impacts are well-known and, according to the letter, should be included in the reauthorized Federal Surface Transportation Act.
The letter was addressed to Reps. James L. Oberstar (D-MN) and John L. Mica (R-FL), who serve as chair and ranking member, respectively, of the House Committee on Transportation and Infrastructure.
For more information, read the full letter to Congress.