The Oct. 1 editorial “A market to save the bay” highlighted an important program with major potential benefits for helping to protect the Chesapeake Bay.

As the Environmental Protection Agency’s program for controlling acid rain demonstrated, trading programs that allow for use of the most cost-effective pollution-control techniques can help achieve important environmental goals. For example, investing $1,000 in planting trees or switchgrass along rural streams could do 10 to 20 times as much to control excess nitrogen, phosphorous and sediment as would an equivalent investment in urban stormwater controls.

This means it could also do 10 to 20 times as much to clean and protect the Chesapeake Bay and the surrounding rivers.

Further, while the flexibility to purchase additional pollution-control reduction credits from farms is no panacea, it might offer the only affordable means of cutting pollution enough to protect our waterways and the living resources they support.

We will also need to invest in adequate safeguards to ensure that local water quality is still protected and that these cost-effective investments are monitored and maintained. Fortunately, living shorelines or buffers composed of trees and switchgrass can be readily monitored.

J. David Foster, Chestertown, Md.

The writer is riverkeeper for the Chester River Association. As an analyst for the Environmental Protection Agency from 1974 to 1993, he helped develop the agency’s policy on emissions trading.