Mike: There is considerable concern about the potential effect of road salts on freshwaters and this is an active area of research. There is substantial evidence that salt levels are increasing in lakes and waterways near roads and that increases in salt concentrations are affecting biota, especially small invertebrates that are critical components of all aquatic food webs. The greatest problems often arise in the spring following snowmelt when salts accumulated over the winter are washed into streams and lakes.