Sweetwater Authority is concerned with the quality of water it provides to its customers. Results from the water-quality monitoring study that the USGS is conducting in the Sweetwater watershed show that the contaminant concentrations in bed sediments, water, and air are reflected in increased urbanization. The bed sediments show the most dramatic evidence of this impact with a sharp increase of persistent organic chemical concentrations over the past 65 years. Water quality is also affected by urbanization in the form of chemicals in the runoff water and deposition of airborne chemicals. The concentrations of the detected organic chemicals in Sweetwater and Loveland Reservoirs are all well below the guidance limits set by State and Federal agencies to protect human health. Many of these compounds are detected only because of the sensitive analytical methods used. This monitoring program provides the Sweetwater Authority with information on what monitored chemicals are present in the reservoirs, and at what concentrations. With this information, the Authority can assess the associated risks, and consider future water treatment and remediation. These results also help focus and support future efforts by Sweetwater Authority to protect the watershed.