The state's commercial real estate industry is squaring off against two prominent environmental groups on pollution-control rules for the Charles River that it says could cost property owners in Greater Boston more than $1 billion.
At issue is a lawsuit the Conservation Law Foundation and the Charles River Watershed Association filed in April to force the US Environmental Protection Agency to require owners of many commercial buildings and apartment complexes — those with at least one acre of rooftops and pavement — to install systems that would clean pollutants from stormwater. The lawsuit would affect many properties in the Charles River watershed, an area that reaches from Boston west to Lincoln and Lexington and south to Bellingham and Franklin and includes 35 municipalities.
NAIOP Massachusetts, a trade group that represents commercial property owners, filed an objection in federal court in Boston on Friday. The business group asserts that the suit, if successful, could force those owners to spend more than $1 billion to install filtration systems.
"We're not denying that there are problems," said David Begelfer, chief executive at NAIOP Massachusetts. "We're just saying there are ways of dealing with this that are more appropriate and more cost-effective."
Stormwater systems can include underground vaults and above-ground gardens and landscaping that filters out phosphorus, which can fuel algae blooms and make waterways inhospitable to fishing and swimming. Phosphorus can be found in car exhaust or decaying plant matter, for example, and can be washed by rainwater into storm drains that eventually empty into the Charles.
Bob Zimmerman, executive director of the watershed association, said he's skeptical of the $1 billion figure. "That's a fairly typical overestimate — to fan the flames," he said.
While sewage-related pollution has improved significantly in the Charles in the past two decades, Zimmerman said phosphorus levels are rising steadily as more of Greater Boston gets paved.
"There's a lot less sewage floating around in it, but that doesn't mean everything is fine and dandy," Zimmerman said. "If we don't do something about it, left unattended, most of the river will be a grown-in swamp over the next three decades."
The lawsuit wants the EPA to use its authority under the federal Clean Water Act to require owners to retrofit existing properties. Currently under a separate Massachusetts law, those systems have to be installed only on newly constructed or expanded developments.
As a result, CLF Massachusetts director Veronica Eady said, only a small number of property owners are being held responsible for all the polluted runoff that threatens the Charles.
"Right now, we're in a situation where the burden of the stormwater runoff and the cost of cleaning up the stormwater runoff is not evenly distributed," Eady said. "The newer dischargers that come on and have to get permits are bearing the costs of their pollution, but existing dischargers, which is something like 80 percent of the discharge, are not bearing their fair share."
John Bensley, a principal at the Southborough engineering firm Beals & Thomas, which helps property owners with conservation-related permits, said it's much more expensive for owners of existing sites to add filtration systems. Landscaped areas of vegetation and soil, known as rain gardens, can act as effective natural filters, but in urban areas expensive manmade filtering systems are often needed, Bensley said.
The EPA had run a pilot program in Milford, Bellingham, and Franklin in 2010 that would have required owners with at least two acres of paved or roofed surfaces to filter stormwater. But the agency, Begelfer said, abandoned the test after determining that it would cost about $180 million in just those three towns.
Begelfer said the total costs would be magnified significantly if the requirement was extended to properties in all 35 municipalities and the threshold for filtering stormwater drops to one acre. Based on the research for the EPA pilot, the expense for retrofitting a property would be at least $150,000 per acre, he said.
"You have a serious problem for existing businesses to find the money to do this work," Begelfer said. "I don't think that a lot of the political leaders are aware this is out there."
Begelfer suggested the EPA be given time to implement a new permitting system for stormwater that's under consideration for cities and towns across the state.
He also said that a new state restriction on phosphorus in fertilizers should reduce the amount that gets into the Charles, and that property owners are increasingly learning about ways to sweep pollutants from their parking lots.
A spokesman for the EPA declined to comment about the lawsuit.
Eady said that NAIOP Massachusetts' involvement in the case will complicate the litigation and simply postpone any remedy, driving up the future costs of addressing the pollution.
"The longer the EPA doesn't regulate," Eady said, "the more expensive it becomes."