St. John's Regional Drinking Water Study I
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St. John’s Regional Drinking Water Study Final Report 143051.00 ● Final Report ● January 2016 ISO 9001 Prepared for: Prepared by: Registered Company Final Report (re-issued) Andrew Gates Feb 1, 2016 Greg Sheppard Final Report Andrew Gates Jan 27, 2016 Greg Sheppard Draft Final Report (re-issued) Andrew Gates Dec 4, 2015 Greg Sheppard Draft Final Report Andrew Gates Oct 9, 2015 Greg Sheppard Draft Report Andrew Gates July 31, 2015 Greg Sheppard Issue or Revision Reviewed By: Date Issued By: This document was prepared for the party indicated herein. The material and information in the document reflects CBCL Limited’s opinion and best judgment based on the information available at the time of preparation. Any use of this document or reliance on its content by third parties is the responsibility of the third party. CBCL Limited accepts no responsibility for any damages suffered as a result of third party use of this document. ISO 9001 Registered Company Final Report 143051.00 February 1, 2016 Mr. Brendan O’Connell, P.Eng. Director of Engineering Dept. of Planning, Development and Engineering City of St. John’s PO Box 908 St. John’s, NL A1C 5M2 Dear Mr. O’Connell: RE: St. John’s Regional Drinking Water Study Final Report We are pleased to provide you with our Final Report for the above-noted project. We have enjoyed working on this project with all of the project stakeholders, and look forward to working with the City of St. John’s and the other stakeholders on the implementation of the report recommendations. Yours very truly, CBCL Limited Greg Sheppard, P.Eng. Project Manager Direct: (709) 364-8623, Ext. 288 E-Mail: [email protected] Project No: 143051.00 ISO 9001 Registered Company 143051.00 RE09 FINAL REPORT 20160131/kw ED: 01/02/2016 10:15:00/PD: 01/02/2016 10:15:00 Contents Executive Summary ........................................................................................................................... iv CHAPTER 1 Project Overview ....................................................................................................... 1 1.1 Background ......................................................................................................................... 1 1.2 Objectives ........................................................................................................................... 1 1.3 Research .............................................................................................................................. 2 CHAPTER 2 Water Systems ........................................................................................................... 3 2.1 St. John’s Water System ..................................................................................................... 3 2.2 Regional Water System ....................................................................................................... 3 2.2.1 Regional-Municipal Responsibilities ....................................................................... 4 2.3 Water Treatment Plants ..................................................................................................... 4 2.4 Water Distribution .............................................................................................................. 5 CHAPTER 3 Water Demands ......................................................................................................... 7 3.1 Historical Flows ................................................................................................................... 7 3.2 Population Projections ...................................................................................................... 11 3.3 Water Demand Projections .............................................................................................. 12 CHAPTER 4 Source Analysis ........................................................................................................ 14 4.1 Reliable Yield ..................................................................................................................... 14 4.1.1 Reliable Yield – Big Triangle Pond ......................................................................... 18 4.2 Wetted Perimeter ............................................................................................................. 25 4.2.1 Study Area and Data ............................................................................................. 25 4.2.2 Environmental Instream Requirement as Threshold ............................................ 26 4.2.3 Comparison of Estimated Flows at Different Thresholds ..................................... 27 4.2.4 Water Availability ................................................................................................. 28 4.2.5 Regionalization of Instream Flow Requirements .................................................. 28 4.3 Watershed Conflicts .......................................................................................................... 30 4.4 Watershed Protection ....................................................................................................... 31 4.5 Groundwater Development Potential .............................................................................. 32 4.5.1 Hydrogeologic Setting ........................................................................................... 32 4.5.2 Aquifer Data .......................................................................................................... 33 4.5.3 Well Yields and Demand ....................................................................................... 34 4.5.4 Results ................................................................................................................... 34 4.6 Source Water Quality ........................................................................................................ 36 CHAPTER 5 Treatment Plant Capacity Analysis ............................................................................ 40 5.1 Existing Treatment Plant Capacities ................................................................................. 40 5.2 Future Treatment Plant Requirements ............................................................................. 44 5.3 Proposed Improvements .................................................................................................. 45 CHAPTER 6 Distribution System Analysis .................................................................................... 57 6.1 Approach ........................................................................................................................... 57 6.2 Hydraulic Design Criteria .................................................................................................. 58 6.2.1 Existing Distribution System Conditions ............................................................... 59 6.2.2 Future Distribution System Requirements ........................................................... 59 6.3 Proposed Improvements .................................................................................................. 61 6.3.1 Bay Bulls Big Pond Service Area ............................................................................ 61 CBCL Limited St. John's Regional Drinking Water Study i 6.3.2 Windsor Lake Service Area ................................................................................... 62 6.3.3 Petty Harbour Long Pond Service Area ................................................................ 62 6.3.4 Development above the 190-m Contour .............................................................. 62 CHAPTER 7 Cost Opinions and Implementation Schedule ............................................................ 79 7.1 Cost Opinions .................................................................................................................... 79 7.2 Implementation Schedule ................................................................................................. 80 CHAPTER 8 Water Conservation ................................................................................................. 82 CHAPTER 9 Conclusions and Recommendations.......................................................................... 83 Appendices A: Plans No. 1 and No. 2 B: Transmission Mains Inventory C: Population Forecasting Study D: Wetted Perimeter Analysis Information E: Water Quality Data F: Storage Tank Calculations G: Cost Opinions List of Tables Table 2.1: Water Treatment Plant Capacities .................................................................................................... 4 Table 2.2: Pump Stations ................................................................................................................................... 5 Table 2.3: Storage Reservoirs ............................................................................................................................ 6 Table 3.1: Measured Water Flows ..................................................................................................................... 8 Table 3.2: Comparison of Average Daily Consumption Rates ........................................................................... 8 Table 3.3: Projected Population - Median Growth Scenario ........................................................................... 11 Table 3.4: Projected Water Demands .............................................................................................................. 13 Table 4.1: Existing Watershed