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Guidelines and Standard Procedures for Continuous Water-Quality Monitors: Station Operation, Record Computation, and Data Reporting

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Guidelines and Standard Procedures for Continuous Water-Quality Monitors: Station Operation, Record Computation, and Data Reporting Guidelines and Standard Procedures for Continuous Water-Quality Monitors: Station Operation, Record Computation, and Data Reporting Techniques and Methods 1–D3 U.S. Department of the Interior U.S. Geological Survey Front Cover. Upper left—South Fork Peachtree Creek at Johnson Road near Atlanta, Georgia, site 02336240 (photograph by Craig Oberst, USGS) Center—Lake Mead near Sentinel Island, Nevada, site 360314114450500 (photograph by Ryan Rowland, USGS) Lower right—Pungo River at channel light 18, North Carolina, site 0208455560 (photograph by Sean D. Egen, USGS) Back Cover. Lake Mead near Sentinel Island, Nevada, site 360314114450500 (photograph by Ryan Rowland, USGS) Guidelines and Standard Procedures for Continuous Water-Quality Monitors: Station Operation, Record Computation, and Data Reporting By Richard J. Wagner, Robert W. Boulger, Jr., Carolyn J. Oblinger, and Brett A. Smith Techniques and Methods 1–D3 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior P. Lynn Scarlett, Acting Secretary U.S. Geological Survey P. Patrick Leahy, Acting Director U.S. Geological Survey, Reston, Virginia: 2006 For product and ordering information: World Wide Web: http://www.usgs.gov/pubprod Telephone: 1-888-ASK-USGS For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment: World Wide Web: http://www.usgs.gov Telephone: 1-888-ASK-USGS Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this report. Suggested citation: Wagner, R.J., Boulger, R.W., Jr., Oblinger, C.J., and Smith, B.A., 2006, Guidelines and standard procedures for continu- ous water-quality monitors—Station operation, record computation, and data reporting: U.S. Geological Survey Tech- niques and Methods 1–D3, 51 p. + 8 attachments; accessed April 10, 2006, at http://pubs.water.usgs.gov/tm1d3 iii Contents Abstract ...........................................................................................................................................................1 Introduction.....................................................................................................................................................1 Purpose and Scope ..............................................................................................................................1 Acknowledgments ................................................................................................................................2 Water-Quality Monitoring Station Operation ............................................................................................2 Site Selection.........................................................................................................................................2 Monitor Selection .................................................................................................................................5 Monitor Configurations and Sensors ................................................................................................5 Types of Sensors ..........................................................................................................................5 Temperature .........................................................................................................................7 Specific Conductance ........................................................................................................7 Salinity .........................................................................................................................8 Dissolved Oxygen ...............................................................................................................8 Percentage of Dissolved Oxygen Saturation ........................................................8 pH ..................................................................................................................................9 Turbidity ................................................................................................................................9 Instrument Acceptance Criteria ..............................................................................................10 Placement of Sensors in the Aquatic Environment ......................................................................10 Stream Cross-Section Surveys ...............................................................................................10 Lake or Estuary Vertical Profiles .............................................................................................11 Use and Calibration of Field Meters ................................................................................................11 Temperature ................................................................................................................................11 Specific Conductance ...............................................................................................................11 Dissolved Oxygen.......................................................................................................................11 pH .........................................................................................................................................12 Turbidity .......................................................................................................................................12 Monitor Operation and Maintenance ..............................................................................................12 Standard Protocol ......................................................................................................................13 Maintenance...............................................................................................................................13 Sensor Inspection and Calibration Check .............................................................................14 Steady-State Conditions ..................................................................................................14 Rapidly Changing Conditions ..........................................................................................14 Alternative Methods for Servicing a Monitor ..............................................................16 Monitor Calibration Criteria .....................................................................................................16 Field Cleaning of Sensors .........................................................................................................17 Field Calibration of Sensors .....................................................................................................17 Temperature Sensors .......................................................................................................18 Specific Conductance Sensors ......................................................................................18 Dissolved Oxygen Sensors ..............................................................................................18 pH Sensors .........................................................................................................................19 Turbidity Sensors ..............................................................................................................20 Troubleshooting Procedures ....................................................................................................20 Requirements for Field Notes and Instrument Logs ............................................................22 Record Computation ....................................................................................................................................22 iv Data-Processing Procedures ...........................................................................................................23 Initial Data Evaluation ...............................................................................................................23 Application of Data Corrections ..............................................................................................24 Corrections for Fouling ....................................................................................................31 Corrections for Calibration Drift .....................................................................................33 Other Corrections .............................................................................................................35 Evaluation of Cross-Section Data Corrections ..................................................35 Computation of Salinity .............................................................................................................36 Computation of Percentage of Dissolved Oxygen Saturation ............................................37 Final Data Evaluation .................................................................................................................37 Maximum Allowable Limits for Reporting Continuous Data ......................................37 Publication Criteria ...........................................................................................................38 Preparation of the Review Package ................................................................................................39
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