Sources of Water Pollution

Our waters quality can be impacted by so many uses and ways that it is hard to know where to begin. The best place to start is with us – humans. Pretty much everything we do as humans as it relates to our use of water results in a change to its quality. Introduction of pathogens (biological), addition of sediments (both biological and physical), nutrients, heavy metals, and acidification are a few of the major impacts.

Then there are the less obvious impacts – routing water from one drainage to another, such as is the case with Butte, Montana’s drinking water supply; impoundment of rivers that form reservoirs; sprinkling our lawns, the leftover water which seeps into the groundwater or runs off into our nearest water bodies carrying with it fertilizers, herbicides and pesticides; and simply using or consuming water, which leaves less water in our systems to transport and dilute natural and human-caused substances.

Here is a table from Water Quality Monitoring – A Practical Guide to the Design and Implementation of Freshwater Quality Studies and Monitoring Programs (J. Bartram and R. Balance, 1996) that shows common human uses of water, and whether they are consumptive and impair water quality.

Common Water Uses

Pretty much everything we do as humans when it comes to water impacts its amount and/or quality. On the following pages, we will illustrate field examples of some of the most common types of water quality impairment observed in our watersheds.