As such, the intention of this document is to provide guidance to municipalities to minimize water pollution from snow disposal activities. Specifically, the proper location and treatment of snow which is stored in piles for disposal is addressed. In addition, salt and salt-sand pile storage is discussed. Snow and Nonpoint Source Pollution Nonpoint source water pollution is defined as human-induced pollution originating from diffuse sources such as agricultural, silvicultural and urban activities. Nonpoint source pollution does not result from a single definable location, such as an industrial discharge pipe, but rather results from land runoff, precipitation, atmospheric deposition, or percolation.
Exceptions are irrigation return flows and urban stormwater flows which are deemed nonpoint sources.
Snow functions as a nonpoint source of pollution since it accumulates a variety of contaminants from the atmosphere, motor vehicles and roadways. These contaminants include salts and salt additives, heavy metals, asbestos, petroleum products such as oil and grease nutrients, bacteria, organic chemicals such as pesticides and PCBs, soil materials and litter. In addition, the solid materials such as sand and other soil particles, which accumulate in roadway removed snow, act as contaminants by filling in streams, lakes and navigation channels. Therefore, snow meltwater can be a serious pollution threat to the environment. In the state of South Dakota, the most obvious environmental impacts from snow disposal activities are related to sediments, organic solids, salts, and salt additives.