Answer: Depending on the native bedrock around the mine site, Acid Mine Drainage may be occuring, reducing the pH (increasing the acidity) of your stream, and causing other contaminants (e.g. heavy metals from mine waste) to dissolve into the stream water. Both the acidity and metals contaminants may be harmful to aquatic life. To determine if Acid Mine Drainage is present, the best time to test your stream water would be during high runoff, such as after a rainstorm and during snowmelt. For the most comprehensive results, you would want to test your stream at different times of the day and during different seasons. Since Acid Drainage is a concern, pH tests would indicate the presence of higher acidity, and turbidity tests would indicate if sediments from the mine are flowing into the creek. Conductivity tests could reveal if there are high concentrations of dissolved solids in the water; if so, additional tests, such as a copper concentration test, would be necessary to determine if the high conductivity was due to mine contaminants, or from other sources of dissolved solids.