WATER QUALITY IN THE GRAND RIVER: A SUMMARY OF CURRENT CONDITIONS (2000-2004) AND LONG TERM TRENDS Prepared by: Sandra Cooke Senior Water Quality Supervisor Grand River Conservation Authority March 2006 Table of Contents Table of Contents................................................................................................................. i List of Figures....................................................................................................................iii List of Tables ...................................................................................................................... v List of Appendices ............................................................................................................. vi Executive Summary.......................................................................................................... vii Introduction......................................................................................................................... 1 Watershed Characteristics............................................................................................... 1 Major Water Uses in the Grand River Watershed .......................................................... 2 Objective of Report......................................................................................................... 2 Methods............................................................................................................................... 8 Water Quality Monitoring............................................................................................... 8 Routine Chemistry, Nutrients and Metals................................................................... 8 Dissolved Oxygen, Conductivity, pH and Temperature............................................. 8 Bacteria and Pathogens............................................................................................. 13 Pesticides................................................................................................................... 13 Data Analysis................................................................................................................ 13 Streamflow, Precipitation and Climate..................................................................... 13 Exploratory Analysis ................................................................................................ 15 Compliance with Water Quality Guidelines and Basin Water Quality Targets ....... 15 Statistical and Trend Analysis .................................................................................. 16 Estimation of Mass Loads and Total Export............................................................. 18 Water Quality Index.................................................................................................. 18 Spills ......................................................................................................................... 19 Results............................................................................................................................... 19 Precipitation, Climate and Streamflow......................................................................... 19 Sampling Regime.......................................................................................................... 22 Nutrients, Suspended Sediments and Major Ions ......................................................... 24 Total Phosphorus ...................................................................................................... 24 Total and Unionized Ammonia................................................................................. 26 Total Nitrate.............................................................................................................. 29 Total Nitrite............................................................................................................... 31 Total Kjeldahl Nitrogen ............................................................................................ 32 Total Nitrogen........................................................................................................... 32 Total Suspended Solids............................................................................................. 33 Chloride..................................................................................................................... 34 Sodium ...................................................................................................................... 35 Total Metals .................................................................................................................. 36 Dissolved Oxygen and Temperature............................................................................. 37 Bacteria and Pathogens................................................................................................. 39 Pesticides....................................................................................................................... 40 Total Mass Loads and Export of Total Suspended Sediment and Total Phosphorus ... 40 Preliminary Trend Analysis .......................................................................................... 42 Statistical Trend Analysis ............................................................................................. 44 i Water Quality Index...................................................................................................... 45 Nutrient Water Quality Index ................................................................................... 45 Metal Water quality Index ........................................................................................ 45 Spills ............................................................................................................................. 48 Discussion......................................................................................................................... 49 Data Limitations............................................................................................................ 49 Data Quantity Limitations......................................................................................... 49 Data Quality Limitations........................................................................................... 51 Water Quality Conditions in the Grand River Watershed ............................................ 51 Upper Grand River.................................................................................................... 52 Middle Grand River .................................................................................................. 53 Lower Grand River ................................................................................................... 56 Conestogo River........................................................................................................ 56 Speed River............................................................................................................... 57 Nith River.................................................................................................................. 58 Trends in Water Quality................................................................................................ 58 Spills ............................................................................................................................. 59 Summary and Conclusions ........................................................................................... 59 Recommendations............................................................................................................. 61 Sampling Regime.......................................................................................................... 61 Monitoring .................................................................................................................... 61 Reporting....................................................................................................................... 62 References......................................................................................................................... 63 Appendices........................................................................................................................ 67 ii List of Figures Figure 1. Land cover in the Grand River watershed.......................................................... 3 Figure 2. Wastewater treatment plants in the Grand River watershed and the population estimates (2001) the plants service. ............................................................................ 4 Figure 3. Percentage of the population receiving wastewater treatment in the Grand River Watershed. .................................................................................................................. 5 Figure 4. Surficial geology of the Grand River watershed. ............................................... 6 Figure 5. Location of the drinking water treatment plants using surface water in the Grand River watershed. Note: the intake in the Eramosa River is for shallow aquifer recharge; the intake for Dunnville is located in Lake Erie. ........................................ 7 Figure 6. Provincial water quality monitoring network in the Grand River watershed... 11 Figure 7. Grand River real-time water quality monitoring network................................ 12 Figure 8. Pesticide monitoring sites in 2003