Worried about mounting conservation mandates and their prohibitive costs, local stakeholders continue to raise concerns about the development of a plan to clean previously overlooked pollution piled up behind a Maryland dam. The strategy, which is in its final planning stages, is likely to have an impact in Lancaster County, especially its farmland, which contributes pollutants to the downstream Conowingo Dam. Now, officials in the county and across the state are concerned about the Conowingo project's costs, as well as its potential to draw resources away from other local clean-water efforts. There are a couple of âpotential pitfalls,â according to Allyson Gibson, coordinator at Lancaster Clean Water Partners, a countywide group of organizations working toward clean water.