The path to a cleaner Chesapeake may look like ribbons of green that line the more than 110,000 miles of streams and rivers that feed the Bay.

The Chesapeake Executive Council adopted a long-term goal of ensuring that all those miles of tributaries be protected with some kind of vegetated buffers. And more specifically, the Council at its Oct. 10 meeting adopted a goal of planting 2,010 miles of forest buffers along streambanks and shorelines by the year 2010.

EPA Administrator Carol Browner, who chairs the Executive Council, said the goal was "bold" and that buffers were a "common sense, cost-effective way to keep pollution out of the rivers that flow into the Bay."

Mounting scientific evidence in recent years has suggested that forested buffers not only improve stream habitat quality, but are also highly effective at filtering sediment and nutrients out of runoff and shallow groundwater before they enter the stream.

"The goals will be challenging," cautioned Pennsylvania state Sen. Noah Wenger, a member of the Executive Council and the chairman of the Chesapeake Bay Commission. "Buffering every mile of stream with some type of buffer, forest or otherwise, will be very difficult, and perhaps not attainable.

"But to help us stay on course, we have at least established some benchmark," he said. "Some may call our mileage goals modest, others may say they're too much, but I think the most important point is that they head us in the right direction, and by being quantifiable, will help us measure our progress along our way."

Adoption of the goal culminated an 18-month process, during which a 31-member panel was created at the direction of the Executive Council in 1994 to develop a policy for the restoration of streamside forests in the watershed.

The panel, which included scientists, government representatives, land managers, citizens and representatives from the farming, development and forest industry communities, agreed that some kind of vegetated buffer should ultimately line all waterways, and that forested buffers in particular provided the greatest range of benefits.

But the panel failed to set a specific goal. Earlier this year, it rejected a 1,200-mile buffer goal in a draft report, in part out of concerns raised by farm groups that any specific goal would ultimately lead to a regulatory program.

Until the Executive Council meeting, it remained unclear whether there would be any specific goal, as Virginia officials, while supporting the forest buffer concept, argued that the issue should be left up to landowners without having a numerical objective.

In fact, three possible forest buffer policies had been printed prior to the meeting: One with a 2,000 mile goal, one with no goal, and one with a blank space for a goal to be filled in.

But in a private session prior to their public meeting, the Council - which includes the EPA administrator, the governors of Maryland, Virginia and Pennsylvania, the mayor of the District of Columbia and the chairman of the Chesapeake Bay Commission, which represents the legislatures of the three states - decided to back a quantifiable goal.

"By setting this goal, we help improve water quality in the Chesapeake Bay, provide for accountability in government and give the public an objective to work toward - 2010 by 2010," Virginia Gov. George Allen said after the meeting.

Maryland Gov. Parris Glendening committed his state to planting 600 miles of forest buffer by the year 2010, a goal that he said exceeded the 360 miles that would have been required if the overall goal was pro-rated among the states. "Maryland is eager to meet that challenge," he said. "We are committed to this additional weight, because we think this is indeed the right thing to do. It also permits us to set a benchmark that is critical for all of us to measure our progress, and to have a key reason to say why we must move ahead every single year."

Pennsylvania Gov. Tom Ridge said, "Just as people depend on water, rivers depend on woodlands. Our forests provide us with many benefits, and one of those is the protection of watersheds, including the mighty Susquehanna, its tributaries, and of course, the Bay beyond."

A statement signed by the Executive Council members commits each state and the federal government to writing a riparian buffer implementation plan with conservation and restoration benchmarks by June 30, 1998. It also commits the states and the federal government - the largest single landowner in the watershed - to conserve existing forests along streams and shorelines.

"Maintaining and restoring buffers along all streams and shorelines will not be an easily achieved goal," the statement said. "Furthermore, reaching these goals will require engaging new partners, energizing the public to plant trees and reforest streams; working with farmers, other landowners and local governments; building new relationships with industry and business; and continuing to develop new and innovative approaches and incentives."

Before European settlement, almost the entire Bay watershed was covered with forests that lined its rivers and streams. Today, aerial surveys indicate that only a little more than half of the streams and rivers in the watershed remain forested.

The 2,010-mile goal would only represent about a 2 percent increase in the amount of streamside forests in the basin. But achieving the goal would require the planting of nearly 150-miles of streambank a year - a threefold increase over the roughly 50 miles of streambank planting estimated to be currently taking place in the watershed.

Adoption of the panel's report and recommendations, and the setting of the 2,010-mile goal, may represent the most far-reaching policy of its kind. The Bay states are also the first region in the country to stake out a goal specifically for forested buffers.

From the Chesapeake Bay through the agricultural fields of the Midwest to the forests of the Pacific Northwest, research has increasingly linked riparian forests with improved stream water quality and habitat. Riparian areas are a transitional area between the edge of the water and adjacent land uses. Research has shown that forest buffers - in many geologic settings - are highly effective at filtering sediment and pollutants out of surface runoff before entering the streams.

In addition, the roots that anchor the trees can remove up to 90 percent of the nitrogen moving through shallow groundwater before it enters the streams. While the Bay states have made progress in reducing the amount of phosphorus entering the Chesapeake, nitrogen has proven more difficult to control.

The Bay states have a goal of reducing the amount of nitrogen and phosphorus entering the Chesapeake 40 percent from 1985 levels by the turn of the century. Excess nutrients cause algae blooms, which degrade water quality in the Bay.

Forest buffers not only remove nutrients, their roots stabilize streambanks, protecting them from erosion and keeping sediment from clouding the water.

Besides protecting water quality, trees improve aquatic habitat for fish and other species. Their leaves shade the streams, helping to protect their aquatic species from sharp fluctuations in temperature. Falling leaves provide the food that makes up the base of the aquatic food web. Roots and fallen tree limbs and trunks also help to form pools and riffles that create the varied habitats needed to support a healthy and diverse stream community.

After reviewing that information, the 31-member Riparian Forest Buffer Panel concluded in its final report that a "sound scientific foundation" exists to support the promotion of streamside forest buffers as a management tool to reduce nutrients and improve habitat. In addition, it said that riparian forest buffers would play an important role in meeting numerous Bay Program goals, including nutrient reduction, expanding beds of Bay grasses and restoring habitat.

Forest buffers could play an especially important role in maintaining the "cap" on nutrient pollution to the Bay that will go into effect after the 40 percent reduction goal is met. The cap, in effect, means that nutrient levels to the Bay must be kept steady despite projected increases in the region's population.

But the panel also reported that landowners tend to view riparian buffers as "more permanent" than other types of buffers, and may need additional incentives or persuasion to plant productive land with trees.

While streamside buffers of any kind are beneficial, the panel concluded that forest buffers "provide the greatest number of benefits and highest potential for meeting both water quality and habitat restoration objectives." It added, though, that forest buffers may not be practical in all situations. In those cases, other buffers would provide some benefits.

The report defines a riparian forest buffer as an area of trees, usually accompanied by shrubs and other vegetation, that is adjacent to a body of water and is managed to protect the stream channel, water quality and improve habitat. It says the buffer width would vary depending on site conditions, topography, adjacent land use and the benefits sought.

The earlier draft report had called for a 75-foot buffer width. An upcoming technical document will provide more detail about determining adequate widths.

The panel said that buffers should be promoted through voluntary means, but that the states and the federal government would need to take actions to better coordinate their programs, improve private sector involvement, offer more incentives and provide more support and education to landowners. It offered a number of suggestions for meeting those goals.