Setting the stage for efforts to reduce water pollution in impaired watersheds around the country, a new environmental program that will be implemented next year in the Chesapeake Bay watershed will make construction projects more expensive and more complex.

Under the program, builders will have to meet initial requirements to reduce stormwater runoff from roofs, driveways and other impervious surfaces prior to the start of building activities. Additional requirements will fall on the home owner.

As with current Stormwater Pollution Prevention Plans (SWPPPs) that must be prepared as a prerequisite for construction activity, home builders will need to obtain good technical assistance to meet the offsets for new growth that will be required by the Environmental Protection Agency.

The effort to restore and maintain the water quality of the Chesapeake Bay will hold nitrogen, phosphorus and sediment runoff entering the bay at baseline levels established by the Chesapeake Bay Total Maximum Daily Load (TMDL) rules that were finalized at the end of 2010.

Once the states implement their offset programs for new growth, builders in the Chesapeake Bay area will be among the first in the nation to have to comply with such regulation.

Late this year or in early 2013, the EPA is expected to introduce a rule that would impose offset requirements for impaired waters nationwide; it will be modeled after the Chesapeake Bay program. This would eventually apply to all watersheds in the U.S. for which TMDLs for nutrients and sediment have been established.

To make up for stormwater pollution resulting from new structures, builders may be able to purchase water quality credits whose costs are determined in a public marketplace; or offsite mitigation measures may be available in some areas.

The credits being sold could come from a farmer, for instance, who installed low-cost Best Management Practices to reduce runoff from the farm.

While home builders would be able to purchase the credits to satisfy the initial offset requirements, home owners would then be required to purchase credits periodically throughout the life of the home.

Credit trading will be complex and be governed by many oversight and verification provisions mandated by the EPA.

Observers say that the success of the Chesapeake Bay TMDL may hinge on the success of the water quality trading programs, which are necessary both for the offset programs and to lower other costs associated with the TMDL.

Late last year, the EPA analyzed the work of each state in the bay watershed on their trading and offset programs; each state in December submitted to the EPA an analysis of how their efforts complied with TMDL requirements.

The EPA early this year is expected to send the states assessments of their offset programs for new growth and it plans to conduct these assessments periodically.

For more information, email Glynn Rountree at NAHB, or call him at 800-368-5242 x8662.