States no longer need to assign nutrient and sediment reduction targets that are measured in pounds to local governments to guide their pollution reduction efforts.

Instead, the EPA said in an October letter that states could use a "narrative" to describe the types of local actions they will implement to achieve broader nutrient goals assigned to them.

The change in emphasis affects the Phase II Watershed Implementation Plans that states must complete by March 30 to show how they are involving local governments to help meet the Chesapeake Bay Total Maximum Daily Load, or "pollution diet."

The TMDL, established by the EPA last December, sets limits on the amount of nitrogen, phosphorus and sediment that can reach the Bay from each state and major tributary.

States prepared Phase I WIPs at that time outlining how they planned to achieve those goals. But many of the specific actions, whether improved stormwater controls or stepped-up efforts to control farm runoff, heavily rely on local governments or conservation districts.

Many officials believe past Bay cleanup plans failed to achieve goals in part because local governments were never fully engaged in those efforts.

As a result, the EPA is requiring more detailed Phase II WIPs that translate state goals to local levels and demonstrate that local jurisdictions understand their Bay cleanup responsibilities.

Originally, it was anticipated that the local targets would consist of nitrogen, phosphorus and sediment limits, measured in pounds, and that they would be set at either the county or small watershed level using the EPA's computer models. But those models are most accurate when estimating nutrient runoff from large areas, and the process of establishing county level goals grew increasingly contentious with both states and local governments. Exacerbating the situation, target numbers for some areas shifted after an update to the model earlier this year.

After a meeting in which states aired their complaints about the process, EPA Region III Administrator Shawn Garvin sent a letter Oct. 5 saying the agency "does not expect" jurisdictions to identify local targets "as pounds of pollutant reductions by county" and pledged to use "common sense" in assessing state plans.

States still have to set local targets in the Phase II WIPs, but Garvin's letter said those targets can instead describe specific actions that will take place, such as the adoption of ordinances by local governments to better control stormwater or setting goals for the number of best management practices that will be implemented to control agricultural runoff in an area. Cumulatively, those local actions still need to achieve the broader nutrient reduction goals set for the state portion of each major tributary.

States are free to determine the size of the local areas they use for target-setting, such as counties, planning commission districts or other geographically defined areas.

"The extent of local involvement is not changing," said Katherine Antos, water quality team leader with the EPA's Bay Program Office in Annapolis. "We still want the states to be actively working with those local partners to make sure they understand what they need to do to help meet the TMDL and also help implement the states' WIPs."

While the EPA recognizes that the states cannot meet with each individual local government by March 30 - there are more than 1,600 local jurisdictions in the watershed - the Phase II WIPs must clearly demonstrate how states have sought to work with local entities involved in carrying out specific actions, whether they are planning districts, county governments, conservation districts, stormwater utilities or others, as well as how they will continue to do so in the future, Antos said.

A key reason for Phase II, she said, is to provide assurance to the EPA that actions needed to meet cleanup goals that are not directly under state control - such as local ordinances - will happen. Without that assurance, the EPA could require further "backstop" actions, such as additional nutrient reductions from regulated sources, to assure TMDL goals are ultimately met.

"A WIP would not meet our expectations if there was no evidence that this local engagement happened, even if every single number is met," Antos said.

Antos said the change did not reflect a loss of confidence in the computer models the EPA uses to estimate the effectiveness of cleanup actions.

"We still have confidence in the model," she said. "We still think it is an important tool to help inform the states and our partners about what actions need to be taken to clean up water quality."

Beth McGee, senior scientist with the Chesapeake Bay Foundation, agreed with the change in tactics, saying the focus on local-level model projections was becoming a distraction.

"Let's get our attention off the model and on implementation. That's where it needs to be," she said. "We're comfortable with moving the attention away from numbers, but keeping it on what practices are you going to get on the ground, and over what time frame."

Some state officials are taking a wait-and-see approach as to whether the EPA is adequately responding to their concerns.

Pennsylvania Secretary of Environmental Protection Michael Krancer faulted the EPA for initially dismissing state concerns about the model's ability to set local pollution targets, but told a Congressional hearing in November that he was encouraged by the agency's change in tone.

"Time will tell whether EPA is serous or just placating, especially regarding the comment about using 'common sense,'" Krancer said in his testimony, saying the state still has disagreements with the EPA over what the model can be used for. "However, it does appear that, at least for the Phase II WIP process, we may now be able to proceed in an 'agree to disagree' mode."

Total Maximum Daily Load at a Glance

The federal Clean Water Act requires a Total Maximum Daily Load for water bodies that fail to meet water quality standards established by states.

A TMDL, or pollution diet, establishes the maximum amount of pollution a water body can receive and still meet those standards. In December, the EPA established a TMDL for the Chesapeake Bay that set limits on the amount of nitrogen, phosphorus and sediment that can enter the Chesapeake from each state and tributary.

Those pollutants are blamed for keeping the Bay from meeting water quality standards for dissolved oxygen, water clarity, and chlorophyll a (a measure of algae growth).

Excess nutrients spur algae blooms that cloud the water which - along with sediment - block sunlight from reaching underwater grass beds that provide important habitat for fish and waterfowl. When the algae die, they decompose in a process that draws oxygen, which is essential to support aquatic life, out of the water, creating so-called "dead zones."

To implement the TMDL, the EPA required states to develop Phase I Watershed Implementation Plans last year describing how they would meet the nutrient and sediment goals. In some cases, the EPA determined those plans did not provide enough assurance that needed nutrient reductions would take place, and required additional "backstop" actions.

Phase II WIPs are to provide more detail about how nutrient reduction goals will be achieved at the local level. Drafts of those plans are due Dec. 15; final ones are due by March 30.

The EPA is also requiring states to establish milestones outlining specific actions they will take in two-year increments. The EPA asked states to submit draft milestones in November. Final milestones will be announced in January.

Unlike past cleanup plans, the EPA can impose a variety of penalties on states if they fail to meet goals set in milestones, or submit WIPs it deems to be inadequate.

The TMDL requires that actions to achieve 60 percent of the nutrient reduction goal be implemented by 2017, and that 100 percent of actions be implemented by 2025.