TRASHCONTROLSTRUCTURESAND EQUIPMENT: A LITERATURE REVIEW ANDSURVEYOFBUREAUOF RECLAMATION EXPERIENCE February 1992 U.S. DEPARTMENT OF THE INTERIOR Bureau of Reclamation Denver Off ice Research and Laboratory Services Division Hydraulics Branch . -"-- ,---, Bureau of Reclamation :PORT STANDARD TITLE PAGl 3. RECIPIENT'S CATALOG NO. 4. TITLEAND SUBTITLE PORT DA TRASH CONTROLSTRUCTURESAND 5. February T692 EQUIPMENT: A LITERATURE REVIEW r 6. PERFORMING ORGANIZATION CODE AND SURVEY OF BUREAU OF RECLAMATION EXPERIENCE 8. PERFORMING ORGANIZATION REPORT NO. I Tony L. Wahl R-92-05 I 9. PERFORMING ORGANIZATION NAME AND ADDRESS I 10. WORK UNIT NO. Bureau of Reclamation 11. CONTRACT OR GRANT NO. Denver Office Denver CO 80225 13. TYPE OF REPORT AND PERIOD L COVERED 12. SPONSORING AGENCY NAME AND ADDRESS 14. SPONSORING AGENCY CODE DlBR I Microfiche and hard copy available at the Denver Office, Denver, Colorado. 16. ABSTRACT The Bureau of Reclamation recently initiated research project NM022, Research and Development for Better Trash Screening and Cleaning Devices, as part of the WATER (Water Technology and Environmental Research) program. This report summarizes the results of initial investigations conducted in this research project, including a literature review, a survey of field problems encountered by Regional and Project offices, and site visits to several locations experiencing problems. This report discusses recent innovations in trashrack, trash screen, and trash rake technology, and makes recommendations for further investigations to be conducted under this research-project. 17. KEY WORDS AND DOCUMENT ANALYSIS a. trashrackd trash screensl trash rakes1 fish screensl aquatic weeds1 ice1 sediment 1 b IDENTIFIERS-- Central Arizona Pmjectl San Luis Valley Project1 mechanical trash rakes ( c. COSATl Field/Group COWRR: SRIM: TRASHCONTROLSTRUCTURESAND EQUIPMENT: A LITERATURE REVIEW AND SURVEY OF BUREAU OF RECLAMATION EXPERIENCE by Tony L. Wahl Hydraulics Branch Research and Laboratory Sewices Division Denver Office Denver, Colorado February 1992 UNITED STATES DEPARTMENT OF THE INTERIOR A BUREAU OF RECLAMATION ACKNOWLEDGMENTS This report is the product of work conducted by a project team consisting of engineers from the Hydraulics Branch, Mechanical Branch, Facilities Engineering Branch, and Water Conveyance Branch in the Denver Office. The author wishes to thank the members of the team, Rick Christensen, Bob Sund, Bill Bouley, and Jim Melena, who each provided input and review for the report. The team extends thanks to Fred Stanek, Arizona Projects Office, and Jim Mueller, San Luis Valley Project, for their assistance with the team's site visits. Mission: As the Nation's principal conservation agency, the Department of the Interior has responsibility for most of our nationally owned public lands and natural and cultural resources. This includes fostering wise use of our land and water resources, protecting our fish and wildlife, preserving the environmental and cultural values of our national parks and historical places, and providing for the enjoyment of life through outdoor recreation. The Department assesses our energy and mineral resources and works to assure that their development is in the best interests of all our people. The Department also promotes the goals of the Take Pride in America campaign by encouraging stewardship and citizen responsibility for the public lands and promoting citizen participation in their care. The Department also has a major responsibility for American Indian reservation communities and for people who live in Island Territories under U.S. Administration. The research covered in this report was funded under the Bureau of Reclamation WATER (Water and Environmental Technology Research) Program allocation (Project NM022, Research and Development for Better Trash Screening and Cleaning Devices). ii CONTENTS Page Introduction. 1 Conclusions. 0 0 0 0. 0 0. 0 0 . 0. 0 0 0 . 0 . 0 0 0 . 0 . 0 0 0 . 1 Recommendations for further research 0" 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 0 0 2 Trash control structures and equipment 0 0 . 0 0 . 0 . 0 0 . 0 . 0 . 0 0 . 0 . 3 Booms 0 0 0 . 0 . 0 . 0 0 0 0 0 0 . 0 0 0 . ,0 0 0 0 0 0 . 0 0 . 0 . 0 . 0 . 0 0 0 0 0 0 . 0 0 0 . 3 Trashracks ,... 0 0 0 . 0 0 . 0 . 0 0 . 0 4 Mechanical trash rakes. 0. 0. 0. 000000. 6 Trashscreens 0.0000000..0000000.000000000.00.000.0000.." o. 0 0.. 9 Traveling water screens. 0 0. 0 0 0. 0 0 0 0 0 0 . 0 9 Stationary screens. 0. 0. 0. 00. 0. 9 Screen perfonnance tests. 00. 00. 0. 00. 0. 000 12 Qeaning options for trash screens 0" 00. 00. 0. 0. 00. 13 Survey of Reclamation field problems. 0 0 . 0 . 0 0 . 0 0 . 0 0 . 0 0 0. 13 Manualraking 00.0.. 0..00.00..0..00.00...0000 0 14 0"""'" Mechanical raking. 0 0 . 0 . 0 0 0 . 0 0 0 . 0 0 . 0 0 . 0 . 0 . 0 0 . 0 . 0 0 0 . 0 0 0 0 0 . 17 Screening effectiveness o. 0 0 . 0 0 0 . 0 0 . 0 0 . 0 0 . 0 0 0 . 0 . 0 0 0 0 0 . 0 0 0 0 0 0 18 Ice problems. 0 0 0 0. 0 0 . 0 0 0 . 0 0 . 0 0. 0 0 0 . 0 0 0 . 0 0 0 0 0 0 . 18 Corrosion. 000. 00. 0. 0. 19 Sediment deposition. 0 . 0 . 0 0 0 0 0 0 . 0 . 0 . 0 0 . 0 0 0 0 0 . 0 . 20 Bibliography. 0 0 0 0 0 0 0 0 0 0 . 0 . 0 . 0 0 . 0 0 . 0 0 . 0 0 . 0 0 0 . 0 0 . 0 0 0 0 0 0 0 0 21 Appendix - questionnaire and results. 0 . 0 0 0 0 0 . 0 0 0 . 0 0 . 0 . 0 . 0 0 0 0 . 0 . 0 0 0 0 0 0- 25 FIGURES Figure 1 Standard Reclamation designs for trashrack crossbars (A and B), and the modified crossbar being used on the Yakima Project and in the Columbia Basin District (C)o 00. 0. 0. 00. 00. 00000. 6 2 Catenary-type trash rake installed on the Government Highline Canal near Grand Junction, Colorado. 00. 0. 0. 0. 0. 00. 0000. 0. 7 3 Hoist-and-carriage type trash rakes at Bouse Hills Pumping Plant on the CAP 0 0 . 7 4 Indexing hydraulic-type trash rake installed at the Santa Rosa Turnout on the CAP ... 0 . 0 0 . 0 0 . 0 0 . 0 . 0 0 . 0 0 . 0 . 0 0 0 0 0 0 0 0 8 5 Section view of a welded wedge-wire screen panel. 0. 0. 0. 00 11 6 General arrangement of a self-cleaning static screen used to exclude fish from small hydropower intakes (Strong and Ott, 1989) 0 0 0 0 0 . 0 0 0 0 0 . 0 . 0 . 12 Hi CONTENTS -Continued Figure Page 7 Problems reported in the survey of project offices and irrigation districts, classified by problem type ..................................... 14 8 Types of debris causing problems with trash control equipment. 15 9 Oeaning equipment in use at sites reportingproblems. 16 10 Types of structures at which problems were reported with trash control . equipment. 16 11 Photograph showingthe wiper installed by field personnel on the catenary rakes at Brady PumpingPlant (CAP) . 17 iv INTRODUCTION Trash control facilities are a vital component of most water resources projects, providing protection for hydroelectric plants, pumping stations, and irrigation stnlctures. On Bureau of Reclamation (Reclamation) projects, these structures must deal with a variety of debris, including aquatic weeds, tumbleweeds, brush, driftwood, and ice. Trash control structures must remove debris that would cause damage or operational difficulties at downstream facilities. Often these stnlctures also must serve as safety barriers, or as barriers to the movement of fish or other aquatic animals. Operation and maintenance problems associatedwith trash control facilitiescost millions of dollars each year in extra labor, equipment repair costs, and interferencewith scheduledwater deliveries. To reduce the number and severity of these problems, Reclamation has established research project NM022, Research and Development for Better Trash Screening and Cleaning Devices, as part of the WATER (Water Technology and Environmental Research) program. The goals of the research project are: . To summarize the current state of the art in trash screening and cleaning equipment . To identify significant problems with existing trash control structures and equipment on Reclamation projects. To seek solutions to these problems. The emphasis of the project is on the structures and equipment most commonly encountered on Reclamation projects, namely trashracks, stationary and traveling screens, and mechanical raking equipment. This report discusses recent innovations, some of which will be selected for further testing and development The initial phase of the study consisted of a literature review, a survey of Reclamation's regional and project offices, and site visits to the CAP (Central Arizona Project) and San Luis Valley Project CONCLUSIONS 1. Reclamation projects experience significant problems with trash control equipment, causing increased operation and maintenance expenses. The most common problems reported in the survey of Reclamation projects were as follows: . Excessive manual raking is required at many sites. Problems are caused by sediment deposition in conveyance channels and around intakes and turnouts. Catenary- and hoist-and-carriage-type trash rakes have many inherent problems. Catenary-type rakes have been ineffective where debris consists largely of tumbleweeds or stringy aquatic weeds. Hoist-and-carriage-typerakes have been ineffective for stringy aquatic weeds. Both rake designs are susceptible to problems caused by sediment deposition at the trashrack. Maintenance costs have been excessive in some cases. 2. Developing and using trashracks and screens that clog less readily, are self-cleaning, or are easier to clean will reduce problems associated with manual raking of trashracks.