Missisquoi Bay Basin Project: Short-term Monitoring Program A Final Report to the International Joint Commission by the Lake Champlain Basin Program 12 August 2011 Prepared by: Eric Howe, LCBP Technical Coordinator Stephanie Strouse, LCBP Technical Associate William Howland, LCBP Program Manager 1 | Page Table of Contents List of Figures ..................................................................................................................................................... 3 List of Tables ....................................................................................................................................................... 3 Executive Summary ......................................................................................................................................... 4 Introduction ........................................................................................................................................................ 4 Intended Uses of Data ................................................................................................................................. 5 Water Quality Monitoring ............................................................................................................................. 5 Monitoring results ............................................................................................................................................ 9 Phosphorus, Nitrogen, Total Suspended Solids ................................................................................ 9 Review of other chemistry parameters ............................................................................................ 10 Loading calculations ................................................................................................................................. 13 Quality Control and QAPP adherence .................................................................................................... 14 Split-sampling exercise ........................................................................................................................... 15 Acknowledgements ....................................................................................................................................... 16 References ........................................................................................................................................................ 17 Appendices ....................................................................................................................................................... 18 Appendix A. Approved Quality Assurance Project Plan for the Short-term Monitoring Project .................................................................................................................................................... 18 Appendix B. EPA WQX Submission Confirmation ........................................................................ 18 Appendix C. Summary of water chemistry results for high-flow (Table C1), low-flow (Table C2), Spring 2011 floods (Table C3) and automated ISCO samples (Table C4) collected from 18 December 2009 to 28 May 2011. ........................................................... 18 Appendix D. Field Assessment to Determine Conformance to Approved QAPP .............. 18 Appendix E. QC data for the chemistry analyses. Field duplicates (Table E1) and field blanks (Table E2) ............................................................................................................................... 18 Appendix F. Cross-sectional profile data for Hungerford Brook, Black Creek, Tyler Branch, Trout Brook, Mud Creek ................................................................................................. 18 2 | Page List of Figures Figure 1. Locations of monitoring stations within the Missisquoi Bay watershed ................... 7 Figure 2. Hungerford Brook hydrograph for the duration of the project (Aug 2009- Aug 2011) with manual and automated sample collection dates. No samples were collected after June 1, 2011 due to laboratory turnaround times. ........................... 9 Figure 3. Mean Nitrogen concentrations across all monitoring locations, Dec. 2009- May 2011. Tributaries are arranged by decreasing mean daily discharge. Error bars are standard error. ........................................................................................................ 11 Figure 4. Mean Total Phosphorus Concentrations across all Monitoring Locations, Dec. 2009-May 2011. Tributaries are arranged by decreasing mean daily discharge. Error bars are standard error. .................................................................................. 12 Figure 5. Mean Total Suspended Sediment concentrations across all monitoring locations, Dec. 2009-May 2011. Tributaries are arranged by decreasing mean daily discharge. Error bars are standard error. ........................................................... 13 Figure 6. Comparison of Vermont and Québec laboratories for split-sampling Total Phosphorus samples. Results are in mg/L due to laboratory reporting constraints. ............................................................................................................................................. 16 List of Tables Table 1. Location information for the monitoring stations within the Missisquoi Bay watershed with type of monitoring data collected (meteorological [Met], chemistry [Chem], discharge [Q]) .................................................................................................... 6 Table 2. Sample Collection Date, Sample Type, and Quality Control sample collections (duplicate or blank) ........................................................................................................ 8 Table 3. Proportion of Mean Dissolved Phosphorus to Mean Total Phosphorus (in %) ............................................................................................................................................................... 10 Table 4. Flow-Weighted Total Nitrogen Loads ..................................................................................... 14 Table 5. Flow-Weighted Total Phosphorus Loads ............................................................................... 14 Table 6. Flow-Weighted Total Suspended Sediment Loads ............................................................. 14 3 | Page Executive Summary Missisquoi Bay, located in the northeastern portion of Lake Champlain, historically has the highest in-lake Phosphorus concentrations of Lake Champlain. Frequent blooms of cyanobacteria in Missisquoi Bay during the summer months compromise the recreational value of this resource to Québec and Vermont residents as well as tourists from other locations around northeastern North America. The International Joint Commission tasked the Lake Champlain Basin Program to initiate a two-year monitoring program of secondary tributaries to the Missisquoi River, the largest tributary to Missisquoi Bay and among the largest tributaries to Lake Champlain. This program was designed to complement and support the Long-Term Monitoring Program, in which monitoring data are collected for over 20 years from all of the major tributaries in the Lake Champlain basin. In this study, water chemistry monitoring stations were established near the mouth of five tributaries (Hungerford Brook, Black Creek, Tyler Branch, Trout Brook, and Mud Creek) to collect nutrient (Phosphorus, Nitrogen), sediment (Tsotal Suspended Solids) and other analytes (i.e. metals, chloride, alkalinity) to support ongoing research in this watershed. A total of 23 high-flow and 6 low-flow samples were collected from each of the five tributaries. An additional 54 samples were collected on Hungerford Brook by an automated sampler (ISCO) to augment the sample size for total Phosphorus and total suspended solids on this tributary. Monitoring data were reduced to high-flow, low-flow, and Spring 2011 flood events. Results from the study indicate that among the five tributaries, Hungerford Brook yielded the greatest mean concentrations for nearly all parameters measured in this study, including flow-weighted concentrations of total Phosphorus, total Nitrogen, and total suspended solids. Introduction Missisquoi Bay has one of the highest in-lake Phosphorus concentrations of any segment of Lake Champlain. Phosphorus loads to and concentrations in the Bay greatly exceed target levels designated by water quality criteria for Phosphorus endorsed by the governments of New York, Québec, and Vermont. Loads of sediment and Nitrogen to the Bay are also a concern. In 2008, the IJC was tasked with assisting in the implementation of a trans- boundary initiative to reduce Phosphorus loadings. Recognizing the recent advances made by the Province of Québec within its areas of jurisdiction, the IJC was requested to coordinate a number of tasks on the U.S. side of the border, in close partnership with the Lake Champlain Basin Program (LCBP). One such task was to establish water quality monitoring locations on tributaries within the Missisquoi Bay Basin to be sampled over a two-year period. Specific details of this project are provided in the approved Missisquoi Bay Basin Project: Short-term Monitoring Program 2009 Quality Assurance Project Plan (STM QAPP 2009, Appendix A); however, a brief overview of the project is provided below. The primary purpose for the two-year Monitoring Program described in this plan was