PROPOSED APRIL 2008 Grenada Lake Watershed Total Maximum Daily Load for Mercury 80 Mercury 200.59 Yazoo River Basin Prepared By Mississippi Department of Environmental Quality TMDL/WLA Branch P.O. Box 10385 Jackson, MS 39289-0385 (601) 961-5171 www.deq.state.ms.us Mercury TMDL for the Grenada Lake Watershed FOREWORD This report has been prepared in accordance with the schedule contained within the federal consent decree dated December 22, 1998 (Sierra Club v. Hankinson, No. 97-CV-3683 (N.D. Ga.)). The report contains one or more Total Maximum Daily Loads (TMDLs) for water body segments found on Mississippi’s 1996 Section 303(d) List of Impaired Waterbodies. Because of the accelerated schedule required by the consent decree, many of these TMDLs have been prepared out of sequence with the State’s rotating basin approach. The segments addressed are comprised of monitored segments that have data indicating impairment. The implementation of the TMDLs contained herein will be prioritized within Mississippi’s rotating basin approach. The amount and quality of the data on which this report is based are limited. As additional information becomes available, the TMDLs may be updated. Such additional information may include water quality and quantity data, changes in pollutant loadings, modification to state water quality criteria, or changes in landuse within the watershed. In some cases, additional water quality data may indicate that no impairment exists. Prefixes for fractions and multiples of SI units Fraction Prefix Symbol Multiple Prefix Symbol 10-1 deci d 10 deka da 10-2 centi c 102 hecto h 10-3 milli m 103 kilo k 10-6 micro µ 106 mega M 10-9 nano n 109 giga G 10-12 pico p 1012 tera T 10-15 femto f 1015 peta P 10-18 atto a 1018 exa E Conversion Factors To convert from To Multiply by To Convert from To Multiply by acres sq. miles 0.001562 days seconds 86400.00 cubic feet cu. Meter 0.028316 feet meters 0.304800 cubic feet gallons 7.480519 gallons cu. feet 0.133680 cubic feet liters 28.31684 hectares acres 2.471053 cfs gal/min 448.8311 miles meters 1609.344 cfs MGD 0.646316 mg/l ppm 1 cubic meters gallons 264.1720 µg/l * cfs gm/day 2.45 cubic meters liters 1000 µg/l * MGD gm/day 3.79 Yazoo River Basin ii Mercury TMDL for the Grenada Lake Watershed CONTENTS Page TMDL INFORMATION PAGE.................................................................................................... vi EXECUTIVE SUMMARY .......................................................................................................... vii 1.0 INTRODUCTION .................................................................................................................... 1 1.1 BACKGROUND ..................................................................................................................1 1.2 WATER BODY SEGMENT LOCATION........................................................................... 1 1.3 WATER BODY DESIGNATED USE................................................................................. 5 1.4 APPLICABLE WATER QUALITY STANDARDS ........................................................... 5 2.0 TMDL ENDPOINT AND WATER QUALITY ASSESSMENT............................................ 6 2.1 SELECTION OF A TMDL ENDPOINT AND CRITICAL CONDITION......................... 6 2.1.1 Mercury Speciation and Chemistry ............................................................................... 6 2.1.2 Mercury Transport and Transformations....................................................................... 7 2.1.3 Mississippi Mercury Criteria (Fresh Water).................................................................. 8 2.2 Mississippi Regulations on Flow Determination.................................................................. 9 2.3 DISCUSSION OF INSTREAM WATER QUALITY ......................................................... 9 2.3.1 Inventory of Water Quality Monitoring Data ................................................................ 9 2.3.2 Analysis of Fish Tissue Data ....................................................................................... 10 3.0 SOURCE ASSESSMENT ...................................................................................................... 11 3.1 POTENTIAL SOURCES OF MERCURY......................................................................... 11 3.1.1 Fluorescent and High-Intensity Discharge Lamps....................................................... 12 3.1.2 Mercury Switches and Relays...................................................................................... 12 3.1.3 Mercury-Containing Thermostats and Thermostat Probes.......................................... 12 3.1.4 Mercury Thermometers ............................................................................................... 12 3.1.5 Gauges, Manometers, Barometers, and Vacuum Gauges............................................ 12 3.2 Point Source Assessment.................................................................................................... 13 4.0 MODELING PROCEDURE .................................................................................................. 14 4.1 MODELING CALCULATIONS ....................................................................................... 14 4.2 Calculation SETUP............................................................................................................. 14 4.3 Source Representation ........................................................................................................ 14 5.0 ALLOCATION....................................................................................................................... 16 5.1 TMDL CALCULATION.................................................................................................... 16 5.2 TMDL ALLOCATIONS .................................................................................................... 16 5.2.1 Wasteload Allocations ................................................................................................. 16 5.2.2 Load Allocations.......................................................................................................... 17 Yazoo River Basin iii Mercury TMDL for the Grenada Lake Watershed 5.3 INCORPORATION OF A MARGIN OF SAFETY .......................................................... 18 5.4 SEASONALITY................................................................................................................. 19 5.5 IMPLEMENTATION PLAN ............................................................................................. 19 6.0 CONCLUSION....................................................................................................................... 21 6.1 FOLLOW-UP MONITORING........................................................................................... 21 6.2 PUBLIC PARTICIPATION............................................................................................... 21 DEFINITIONS.............................................................................................................................. 22 ABBREVIATIONS ...................................................................................................................... 26 REFERENCES ............................................................................................................................. 27 APPENDIX A: Mercury Use Outline.......................................................................................... 29 APPENDIX B: Mississippi Fish Advisories ............................................................................... 33 TABLES Table 1. Listing Information ....................................................................................................... vi Table 2. Water Quality Standard.................................................................................................vi Table 3. NPDES Facilities .......................................................................................................... vi Table 4. Total Maximum Daily Load.......................................................................................... vi Table 5. Water Body Identification for the Grenada Lake Watershed Mercury TMDL ..............1 Table 6. Grenada Lake Watershed Landuse Distribution .............................................................4 Table 7. State of Mississippi Water Quality Criteria for Intrastate, Interstate, and Coastal Waters .............................................................................................................................5 Table 8. Water Quality Data ........................................................................................................9 Table 9. Fish Data Analysis ........................................................................................................10 Table 10. Permitted Point Sources ................................................................................................13 Table 11. Facilities Recommended for Mercury Monitoring .......................................................15 Table 12. Facilities Recommended to Perform Mercury Effluent Monitoring.............................17 Yazoo River Basin iv Mercury TMDL for the Grenada Lake Watershed FIGURES Figure 1. Location of the Grenada Lake Watershed.......................................................................2 Figure 2. The Grenada Lake Watershed – 303(d) Segment Locations ..........................................3 Figure 3. Grenada