Virginia has completed a draft strategy to guide nutrient reduction efforts in the Potomac and Shenandoah rivers which, for the first time, estimates the cost of achieving the 40 percent nutrient reduction goal for its portion of the river basin.

The draft strategy said it would take five to nine years to implement the plan, implicitly acknowledging that the year 2000 nutrient reduction goal will not be met. The total cost over that time could hit $193 million, the draft document said.

The strategy was out for comment during the last portion of November, and is to be revised and presented to the General Assembly by the Allen administration by Jan. 1.

The cost estimate will create a debate at next year's General Assembly over how to provide the funds - and how to share the cost among localities and the state. "There needs to be a substantial local share, a substantial state share and a substantial federal share," said Deputy Secretary of Natural Resources Brian F. Mannix.

Local governments have strongly backed state cost-share to help implement the strategy, which means the Commonwealth's cost could be between $82 million and $99 million over the five to nine year implementation period, the document said.

Del. W. Tayloe Murphy Jr., D-Westmoreland, said he plans to introduce legislation that would split the cost evenly between local and state governments. "It is time to get off dead center and start taking some positive action to achieve the goals to which we have committed the commonwealth," he said.

The prospect for state funding improved in late November when budget analysts reported that the state is likely to have a budget surplus of about $265 million next year. The Potomac cleanup has been mentioned as a potential use for some of the surplus.

Still, a plan that steers significant money into the Bay cleanup effort could spur a lively debate as only about half of Virginia is in the Chesapeake drainage.

Also, the state's cost for implementing Bay-related nutrient reductions would likely rise as it completes tributary nutrient strategies for the Rappahannock, York, James and other eastern and western shore basins over the next two years as required by a law passed by the General Assembly.

According to the draft Shenandoah and Potomac strategy, nitrogen loads from Virginia's portion of the basin fell 9 percent from the 1985 baseline through 1994 while phosphorus declined by 27 percent.

But, the strategy noted, if only those nutrient reduction programs currently in place or planned are implemented, nitrogen and phosphorus levels would remain largely unchanged through the turn of the century. That's because those reductions will be offset by increased runoff pollution and wastewater discharges resulting from growth in the watershed, the report said.

Runoff, much of it from agricultural land and discharges from wastewater treatment plants, is the largest source of nutrient pollution in the watershed.

As part of the strategy development process, Virginia's portion of the Potomac and Shenandoah watershed was divided into four regions, with citizens and leaders from local governments and businesses devising cost-effective nutrient reduction strategies for each.

Much of the reduction goal, especially in the more rural portions of the basin, would be achieved through greater implementation of agricultural management practices that reduce runoff, such as the more precise application of fertilizer or the installation of buffer strips between fields and streams.

But to come close to meeting the goal, the strategy also calls for upgrading most of the larger wastewater treatment plants in the watershed to remove nutrients, especially nitrogen, which has proven to be particularly difficult to control.

If those regional plans were fully implemented, the draft strategy said, the state would achieve a 36 percent reduction for both nitrogen and phosphorus - slightly below the 40 percent goal - at a cost of about $125 million.

The lion's share of that cost, up to about $115 million, would be required to upgrade wastewater treatment plants.

Achieving the full 40 percent reduction, the report said, would cost significantly more. One way of doing it would be to install advanced nutrient removal technology at all, rather than selected, wastewater treatment plants in the basin - something that would cost an additional $34 million to $67 million.

Because of construction schedules for major wastewater treatment plant projects, the draft strategy said it would take five to nine years to implement all of the recommendations.

The Virginia Association of Municipal Wastewater Agencies has adopted a position paper saying that the state should provide grant funding for at least half of the cost of wastewater treatment plant upgrades for the nutrient control strategy to avoid huge rate increases for customers.

"If this is a partnership, as everyone says it is, then shouldn't the state be a partner in helping to fund this effort?" said James T. Canady, VAMWA chairman.

If it took five years to implement the plant upgrades, the document estimates that the annual implementation cost would be between $16 million and $20 million for the state, and $15 million and $19 million for local governments.

Virginia, Maryland, Pennsylvania and the District of Columbia agreed in 1992 to develop nutrient reduction strategies for each of the Bay's major rivers. The strategies were to achieve the Bay Program's overall objective of reducing the amount of nitrogen and phosphorus reaching the Chesapeake 40 percent by the turn of the century.

So far, Maryland has completed 10 separate tributary strategies and formed special teams to oversee the implementation of each. The District has completed a strategy which primarily achieves its goal by upgrading the Blue Plains Wastewater Treatment Plant.

Pennsylvania has developed a draft strategy that falls short of the 40 percent goal. Officials there are exploring options to achieve the full reduction.

Virginia has been developing its strategy since 1993. Officials have said that the Potomac strategy would serve as a model for completing the strategies for the state's other rivers.

After the nutrient reductions have been achieved, the Bay jurisdictions have pledged to "cap" the amount of nutrients reaching the Bay at those reduced levels, despite anticipated growth in the watershed.

Excessive amounts of nutrients are considered to be the chief water quality problem in the Bay. When large quantities of phosphorus and nitrogen stimulate the growth of more algae than can be consumed by fish and other organisms, it results in the creation of large algae blooms.

The blooms cloud the water, blocking sunlight to important Bay grasses that provide food for waterfowl and important habitat areas for blue crabs, juvenile fish and other Bay life.

When algae die, they sink to the bottom and decompose in a process that depletes the water of oxygen needed by other creatures.