From a stormwater perspective, terrain matters a lot more than state boundaries. However, the bulk of stormwater research has taken place in only one terrain.
Roof runoff quality is fundamentally determined by the nature of the roof surface, which can be quire diverse.
It may surprise you, but lawns and turf grass is now the largest crop grown in the Chesapeake Bay watershed.
Bay stormwater managers are rapidly shifting their focus to reduce the volume of runoff rather than merely treating its quality.
Chloride is one of the main components of road salt and there is virtually no way to remove it once it gets into the watershed.