WASHINGTON COUNTY — To accommodate potential growth without exceeding water pollution limits, Washington County will have to continue to improve wastewater treatment technologies, trade load allowances among treatment plants and modify land-use policies, a proposed planning document states.
That document — a new, state-mandated “water resources element,” or WRE, to be added to the county’s comprehensive plan — is scheduled to go to public hearing Tuesday night during a joint session of the Board of County Commissioners and the Washington County Planning Commission.
A state law passed in 2006 required all counties and municipalities that exercise planning and zoning authority to adopt a WRE analyzing whether their water resources will be adequate for the land use proposed in their comprehensive plans.
Among other findings, Washington County’s draft WRE says that sediment loading in Antietam Creek and Conococheague Creek exceed the amount those streams can receive if they are to meet water-quality standards.
Sediment, such as soil, can cloud water, blocking sunlight from submerged plants, and can clog gravel beds used by fish for laying eggs, according to information on the Maryland Department of the Environment website.
Nitrogen and phosphorous levels entering waterways also are closely regulated due to their environmental impact.
The WRE calls for expansion of programs promoting “best management practices” — such as no-till farming and riparian forest buffers — to reduce pollutant runoff from agricultural operations.
It also calls for “Enhanced Nutrient Removal” upgrades to several of the county’s wastewater treatment plants to reduce pollutants discharged into waterways.
Even with the upgrades, the treatment plants would have to engage in “bubble” and “trading” practices in order to serve the level of development allowed by the county’s zoning and not exceed pollution limits, the WRE says.
The bubble and trading allowances would mean that if one plant’s pollutant load is below the maximum level, that excess “load” could be transferred to another plant at which the load was still too high.
Another finding in the WRE is that the percentage of impervious surface in the Conococheague Creek watershed is already 10.55 percent, high enough to pose mild environmental impact. With full build-out of growth allowed under county planning documents, that percentage would increase to 12.22 percent, the WRE says.
At 11 percent to 25 percent impervious cover, sensitive fish and aquatic insects begin disappearing from a stream, the report says. At more than 25 percent, the stream “can no longer support a diverse aquatic biological community,” it says.
The Conococheague Creek is the county’s only major watershed that would exceed 10 percent impervious area at full build-out, the WRE says.
If you go ...
What: Public hearing on proposed Water Resources Element amendment to the Washington County Comprehensive Plan
When: Tuesday, 7 p.m.
Where: Washington County Courthouse, courtroom 1
The proposed amendment and related documents are available online at www.washco-md.net.