Trying to make the blacktop greener

States working to curb pollution from road runoff

Every time it rains, a soup of chemicals washes off roadways: Brake fluid, oil, salt, antifreeze, and heavy metals from tens of thousands of cars pour off the asphalt and, often, into rivers and streams.

Until recently, this form of pollution received little attention from regulators and environmentalists, but a movement is slowly building to create what may seem a contradiction: green highways.

Two weeks ago a federal judge in Boston ruled that the Massachusetts Highway Department was violating the federal Clean Water Act and ordered the agency to better control storm water from roadways in urban areas. Meanwhile, some states are beginning to capture and filter storm water before it reaches waterways, using vegetation and porous median strips among other solutions.

"All the pollution that runs off highways is put very quickly into our waterways," said Christopher M. Kilian, director of the Clean Water Program and the lead lawyer in the Massachusetts case for the Conservation Law Foundation, a Boston-based environmental group that sued the Highway Department. "But there are approaches we can use to stop it."

Once, the biggest problems facing waterways such as the Charles River and Boston Harbor were obvious. Raw sewage and toxic chemicals from homes and factories stank and made stepping in the water so foul people would avoid any contact. A decades-long cleanup of these pollution sources, mandated by the Clean Water Act, has gone a long way toward restoring waterways. Boston Harbor now sparkles on many summer days, and the Charles is clean enough that a 1-mile swim is scheduled there tomorrow.

Yet these scrubbing efforts were relatively simple because the pollution could easily be traced back to its sources. Now environmentalists are focusing on a problem that is more dispersed: runoff, carrying everything from dog waste to fertilizer, from lawns, sidewalks, roadways, natural areas, and farms. It is the main reason about 40 percent of rivers, lakes, and estuaries are not clean enough to meet fishing or swimming standards, according to the US Environmental Protection Agency.

While it's difficult to tease out the highways' share of the problem, federal officials are focusing on them because so many contaminants are washed from roadways, solutions are available and straightforward, and the federal Clean Water Act requires highway departments to deal with the problem.

"Most roads have no controls at all," said Nancy Stoner, director of the Clean Water Project at the Natural Resources Defense Council. Her group is involved in a long-running lawsuit seeking to force the EPA, which enforces the Clean Water Act, to require anyone building roads, schools, and any private construction to use specific, proven technologies to minimize storm water runoff.

There are many highway contaminants. Chloride, sodium, and calcium can accumulate on the pavement from salt and sanding operations. Ordinary wear and tear causes cars to shed oil, grease, rust, and rubber particles. Once the contaminants are washed into waterways, they can be consumed by fish, frogs, and other aquatic life, or settle in the water, contributing to contaminant levels.

The green highway movement also includes advocacy for the use of recyclable materials for pavement or the creation of wildlife crossings. But environmentalists and scientists say storm water runoff is by far the most pressing problem - and the most expensive to fix.

The solutions are hardly high-tech. The goal is to slow water running off pavement and allow it to percolate through soil, vegetation, and stones, which cleanse it before it reaches waterways. Porous road shoulders and medians allow water to migrate into the ground instead of flowing directly into storm drains and rivers. Man-made ponds and adjacent wetlands hold runoff until it can evaporate or seep through soil. Still, such solutions can be difficult in highly urban areas where space is at a premium.

Headway is being made around the country. In January, California promised to reduce runoff pollution from its freeways in Los Angeles and Ventura counties by 20 percent to settle a lawsuit the Natural Resources Defense Council brought in 1994. Two years ago, the EPA, the Federal Highway Administration, several mid-Atlantic states, and other groups formed the Green Highways Partnership to test small-scale green highway programs that can serve as national models. Maryland has constructed man-made ponds on a pilot basis to hold highway storm water so it can filter through soil more slowly. Universities from Villanova to Louisiana State are working to perfect porous pavement technology.

In Massachusetts, state highway officials say they try to incorporate storm water management when building roads or reconstructing them in urbanized areas. But in its lawsuit, the Conservation Law Foundation said the state wasn't doing anything about runoff from the vast network of roads.

Federal District Court Judge William G. Young agreed, saying highway storm water on Interstate 190 in Lancaster was clearly contributing to pollution in a nearby waterway, as were two Route 495 sites that were polluting the Charles River. He also said the agency needs to do a better job assessing how to keep pollution out of waterways in urbanized areas. He told MassHighway to come back to him with a revised storm water management plan by the end of 2009. He praised the agency for doing a good job given fiscal and other constraints, but said "best efforts, of course, is not the standard."

MassHighway officials said they were pleased with the decision because the judge took pains to compliment them on many of their efforts. They acknowledged that they have not initiated new storm water management technologies on roadways that aren't undergoing any other work because of its prohibitive cost, probably hundreds of millions of dollars if storm water controls were installed on state highways in urban areas. They are now waiting for a US Geological Survey report that will help determine where and how pollution is running off highway segments so they can decide where to focus clean-up efforts.

"I think [the judge] was saying, given the breadth of our responsibility, we are doing a pretty good job," said Highway Commissioner Luisa M. Paiewonsky. "[We are] improving a plan already underway."

By Beth Daley
Globe Staff / June 14, 2008