AWWA JAW31620

Waterborne particulates, turbidity, and temperature were used to characterize the influence of surface water on collector wells constructed in alluvial river valleys. No insects, other microorganisms, Giardia, or other large-diameter pathogens were found in water from the collector wells, although Giardia were detected in adjacent rivers. The turbidity of the water produced by the collector wells remained virtually constant throughout the year and did not fluctuate with changes in river turbidity. These results support the conclusion that the influence of surface water on collector wells should not be characterized as "direct." Temperature data, however, show that the collector wells are influenced by the surface water, but these data alone are insufficient for deciding whether this influence is direct. Includes 7 references, tables, figures.