St. Mary's officials lay out watershed implementation options, plan preliminary submission to state by Nov. 18

St. Mary's County Department of Land Use and Growth Management staff on Tuesday briefed the Board of County Commissioners on the Chesapeake Bay total maximum daily load (TMDL) and the county's Phase 2 Watershed Implementation Plan and asked the board to allow a preliminary submission to the state by Nov. 18 that would include items already in the county's capital plan.

The briefing explained why the county must reduce nitrogen, phosphorus and sediment and set out options for achieving reductions — including septic-system upgrades to best available technology (BAT), targeted sewer connections, stormwater retrofits, forest planting and pilot projects — and summarized early cost estimates and trade-offs.

The WIP matters because the U.S. Environmental Protection Agency's Chesapeake Bay TMDL (established Dec. 2010) assigns nutrient and sediment limits to jurisdictions in the Bay watershed and requires jurisdictions to show how they will meet reductions over time. County staff said Phase 2 will cover milestones through 2017 and feed a subsequent plan to 2025.

County staff said the TMDL calls for roughly 25 percent reduction in nitrogen and 24 percent reduction in phosphorus for the bay basin and that Maryland and its counties must identify…