Frederick County Government conducted a study of the health of its watersheds from 2008-2011. The study looked at indicators of water quality including the health of its stream bugs, physical habitat in the streams, the presence of streamside forest buffers, stream erosion, and the amount of nitrogen and phosphorus in the streams. Streams in the report are shown to be in generally good condition in forested areas, but degraded once the forest is replaced by other land uses. Watersheds range between fair and poor for bugs, which is typical for watersheds in Maryland. The study shows a strong relationship between the amount of phosphorus in the water and the health of stream bugs. These bugs are important because they are at the bottom of the food chain.
The study also shows that streamside buffers in Frederick County's waterways are generally good. Frederick County's waterways still support brook trout in some areas, though they are confined to the forested areas in the mountains. This study does not suggest that the waters are unsafe for fishing, swimming, or drinking. The study shows that though the state has listed most of the waterways in Frederick County as impaired for phosphorus, there is a great deal of variability within watersheds and many areas where phosphorus is not high. This suggests a more refined map at a smaller scale should be used by the state to identify impairments.