The EPA is currently considering the first national guidelines for controlling stormwater runoff discharge from construction and development sites, which could affect builders and buyers through stricter regulations expected to add thousands of dollars to a new home's cost.

EPA is weighing three options that range from requiring developers to install sediment basins to mandating elaborate job-site monitoring and control systems that would limit sediment discharge to levels far below those currently allowed by most states.

“This proposal builds a foundation for cleaner streams and greener neighborhoods through improved treatment technologies and prevention practices,” said Benjamin Grumbles, EPA’s assistant administrator for water, in a prepared statement.

The agency is accepting public comments on the proposed stormwater regulations through Feb. 26, 2009.

The NAHB takes a dimmer view of EPA’s proposals. To the association, the EPA's proposal represents yet another costly regulation at a time when builders are struggling to sell homes. Ty Asfaw, an environmental policy analyst at the NAHB, estimates that the enforcement of these options could add anywhere from $16,000 to $35,000 to the cost of a house within affected developments, depending on the area's rainfall and soil composition.

Ironically, given its proposal for a national standard, EPA determined in 2004 in response to complaints that establishing national effluent limitation guidelines “would not be the most effective way” to control sediment discharge from construction job sites; the federal agency preferred to leave regulations to the states.

However, the EPA's hand was forced by a 2006 court ruling that said EPA had a “mandatory duty” to “promulgate” sediment discharge standards. “That judgment had a lot to do with our change in thinking,” says Janet Goodwin, chief of the agency’s technology and statistics department. Indeed, she tells BUILDER that the methodology EPA used to devise its new proposal was “not that much different from” how it derived its opinion on stormwater management four years earlier.

In its report dated Nov. 11, EPA details the three options in its proposal:

  • The first would establish minimum sizes for sediment basins at construction sites with 10 or more acres under development. Permits would require developers to install basins that could store up to 3,600 cubic feet per acre of runoff, or be designed to store runoff from a local area’s maximum rainfall during a 24-hour period. Under this choice, an estimated 120,700 acres—or 20 percent of the total acreage under development annually for residential, commercial and transportation—would require sediment basins. (Residential accounts for nearly half of the total acreage developed annually, according to EPA’s calculations.) Annual cost? $132 million annually to implement. 

  • The second option is similar to the first, but sites of 30 acres or more would also be required to meet a national numeric limit on stormwater “turbidity" that would be far stricter than most state regulations. This option also sets parameters for clay content in soil and rainfall runoff erosion. The EPA estimates that approximately 40 percent of the acreage developed annually for construction would need to meet the new sediment limitation standard and that 11 percent would require sediment basins under this option, which will cost perhaps $1.9 billion annually.

  • The third option has the same requirements as the first, but also requires all sites of 10 or more developed acres to meet the same strict standard turbidity levels as the second option, but without any consideration for the soil type or rainfall runoff erosion. This third approach could cost $3.8 billion annually.

Asfaw concedes that most builders could probably live with the first option, which essentially standardizes best management practices. However, NAHB is also assembling its own data to challenge the rules overall because of concerns about the objectivity of the information form which EPA drew its conclusions. The government agency says it determined its sediment limitations for construction and development based on its evaluation of more than 6,600 turbidity measurements from 19 treatment systems on 17 sites in three states. The Oregon Department of Environmental Quality provided statistics, but so did two water-treatment vendors, which concerns the NAHB.

In all probability, says Goodwin, EPA will make adjustments to its proposal before making its final determination. Under court order, EPA must put its guideline into effect no later than Dec. 1, 2009.

John Caulfield is senior editor at BUILDER magazine.