Most people mistakenly attribute stormwater pollution to the downfall of rain or the melting of snow. The truth, however, is that the pollutants are in the soil–the water from the downpour or melting of snow merely facilitates the flow of these pollutants to the streams or rivers, which then become affected as well.
 Mobile Pollutants
 Usually, these are from products that use a mixture of potently strong chemicals, such as fertilizers, pesticides or even plain soap. Once these are sprayed on or transmitted to the soil, it is absorbed and so consequently pollutes the soil.
 When the rain falls, or when the snow covering the soil melts on top of it, it softens the soil. Depending on how heavy the rainfall is or how soft the soil has become, it’s also very possible that chunks of it will be broken off and taken along with the flow of the water. Even if the soil isn’t eroded, however, the pollutants already in it could still seep through to the water.