Research Problem and Background:
Degraded water quality is a common problem throughout the U.S. and the world. Under-standing the extent and severity of water quality problems is often difficult, but neces-sary. Accurate and efficient field and laboratory techniques are needed to identify and evaluate water quality problems. The information developed in this research project helped develop methods for water quality monitoring that were especially suited for Reclamation water projects.

Project Objectives:
The objectives of this project were to develop toxicity testing methodologies, evaluate hyporheic sampling for study of water quality, study effectiveness of aquatic mosses for monitoring metals, develop methods to use leaf pack decomposition for monitoring pollution sources impacting water systems, and develop techniques for improving water quality within projects.

Overall Outcome or Conclusions:
Newly developed rapid toxicity tests were shown to be useful tools in water quality testing. Studies of hyporheic sampling indicated that this zone is important in the control of metal fluxes from ground to surface water. Mosses were shown to be useful and efficient bioconcentrators of metals. Leaf pack decomposition did not effectively show differences in water quality; however, specific invertebrates proved to be excellent indicators of water quality conditions.

Partners:
Eastern Colorado Area Office, EPA Region VIII, U.S. Forest Service.

Publications and/or Other Deliverables
Holdren, G.C., and S.M. Nelson. 1998. Water supply and water quality in Totten Reser-voir, Montezuma County, Colorado. USBR-TSC Technical Memorandum No. 8220-98-9.

Nelson, S.M. 1996. Monitoring of heavy metal concentrations in the Arkansas River using transplanted bryophytes. USBR-TSC Technical Memorandum No. 8220-96-18.

Nelson, S.M. 1998. Leaf pack processing and macroinvertebrate colonization: bioassess-ment tools for a high altitude regulated system? Submitted to Freshwater Biology.

Nelson, S.M., and R.A. Roline. 1996. Distribution of aquatic macroinvertebrates in relation to stream flow characteristics in the Arkansas River. USBR-TSC Technical Memorandum No. 8220-96-19.

Nelson, S.M., and R.A. Roline. 1996. Recovery of a stream macroinvertebrate community from mine drainage disturbance. Hydrobiologia 339:73-84.

Nelson, S.M., and R.A. Roline. 1996. Results of macroinvertebrate sampling on Lake Fork and some recommendations for monitoring Dinero Tunnel impacts on Lake Fork. USBR-TSC Technical Memorandum No. 8220-97-17.

Nelson, S.M., and R.A. Roline. 1997. Assessment of Leadville mine drainage tunnel impacts on the upper Arkansas River using hyporheic pot samples. USBR-TSC Technical Memorandum No. 8220-97-10.

Nelson, S.M., and R.A. Roline. 1997. Comparison of rapid toxicity tests with a standard acute test. USBR-TSC Technical Memorandum No. 8220-97-9.

Nelson, S.M., and R.A. Roline. 1998. Evaluation of the sensitivity of rapid toxicity tests relative to daphnid acute lethality tests. Bull. Environ. Contam. Toxicol. 60:292-299.

Nelson, S.M., and R.A. Roline. 1998. Relations between metals and hyporheic inverte-brate community structure in a river recovering from metals contamination. USBR-TSC Technical Memorandum No. 8220-98-7. (Also submitted to Hydrobiologia.)