Sewage Works Improvements Town of Huntsville Mountview Wastewater Treatment Plant to Golden Pheasant Wastewater Treatment Plant Conveyance Strategy Public Information Centre (PIC) November r 29, , 2018
PURPOSE The District Municipality of Muskoka is undertaking an addendum to the 2014 Class Environmental Assessment (Schedule C) for servicing in the Town of Huntsville. The pending amendment proposes a relocation of the current Golden Pheasant Wastewater Treatment Plant (WWTP) outfall from the mouth of the Muskoka River to the east/central basin of Fairy Lake. Additionally, it is proposed that the current Golden Pheasant WWTP outfall pipe be repurposed as the conveyance forcemain between the anticipated Mountview Sewage Pumping Station and Golden Pheasant WWTP. The Purpose The purpose of the Public Information Centre (PIC) is to present information on the addendum and collect input from community members and other stakeholders as part of the Class Environmental Assessment (Class EA) and consultation process. Your Role We invite you to ask questions, raise your concerns and provide comments. All comments will become part of the formal Record of Consultation for the addendum.
BACKGROUND 1989 Class Environmental Assessment • Developed to address long term Town of Huntsville wastewater servicing and management • Preferred Solution involved a two-phase approach • PHASE 1 Construct new Golden Pheasant Wastewater Treatment Plant (1996) and maintain Mountview Wastewater Treatment Plant (Ongoing) • Upgrade/expand Golden Pheasant Wastewater Treatment Plant • Re-purpose Mountview Wastewater Treatment Plant to Sewage Pumping PHASE 2 Station with conveyance from Mountview Sewage Pumping Station to (Deferred) Golden Pheasant Wastewater Treatment Plant • Decommission Mountview Wastewater Treatment Plant 2014 Class Environmental Assessment • Revisited the 1989 Class EA for validation of the Preferred Solution • Outcome to continue with implementation of Phase 2 • Three Public Information Center (PIC) sessions conducted; overall positive public input to proceed with Preferred Solution • Endorsed by Town of Huntsville Council on April 28, 2014
MUNICIPAL CLASS EA PLANNING AND DESIGN PROCESS An addendum is an established part of the Class EA process that allows for modifications to a project scope prior to implementation. The addendum contains details of the change, considers the effects of the change and mitigating measures. Only the proposed changes are open for review under the Class EA addendum.
CONVEYANCE & OUTFALL ALTERNATIVE Proposed Conveyance/Outfall EA Addendum to 2014 Class EA Conveyance • Convert existing Golden Pheasant Wastewater Treatment Plant outfall pipe to a conveyance forcemain (via slip pipe technology) • Utilizes 2014 Preferred Solution: Option 1 routing Outfall • Install new outfall from Golden Pheasant Wastewater Treatment Plant into east/central basin of Fairy Lake
ALTERNATIVE CONVEYANCE & OUTFALL ALIGNMENT Blue circle indicates Fairyview WTP intake protection zone Golden Pheasant WWTP Fairyview WTP Proposed New Outfall Location Open cut forcemain Slip line forcemain installation installation Existing Golden Pheasant WWTP Outfall Mountview WWTP
PROPOSED OUTFALL CONSIDERATIONS Blue circle indicates Fairyview WTP intake protection zone Proposed Outfall Location Golden Pheasant Gray areas indicate WWTP Outfall properties with municipal water supplies Mountview WWTP Outfall Blue areas indicate properties with private water supplies including waterfront homes and cottages
EFFECTS OF PROPOSED ALTERNATIVE New Golden Pheasant WWTP Outfall Advantages Key step in decommissioning Mountview WWTP Previously identified in 1989 Class EA Gravity flow (lower energy cost than pumping to existing outfall) Maintains regulated standards for water quality Dispersion modelling conducted by GHD and Hutchinson Environmental Sciences Ltd. Conveyance/Forcemain Routing Advantages Utilizes 2014 Preferred Solution Option 1 routing Reduced overall open trench construction (Highway 60) Results in $1,000,000 in savings compared to 2014 Class EA Preferred Solution No increase in residential construction disturbance Synchronization of DMM/Town of Huntsville road works projects
Fairy Lake Dispersion Modelling • Intensive numerical modelling techniques; technical review provided by Hutchinson Environmental Sciences Ltd. • Based on very high quality effluent from Golden Pheasant WWTP • Conducted to predict the effects of the discharge at the proposed Golden Pheasant WWTP outfall location; water quality, extent of the mixing zone, thermal/ice regime • Mixing zone at 1% concentration does not interact with 1- kilometer radius Intake Protection Zone (IPZ-1) or shoreline • Safe-ice thickness (for walking) maintained; duration of ice cover reduced by 8 days in April (in typical year) • 6 centimeter reduction in maximum ice thickness (in typical year) at outfall location
Fairy Lake Dispersion Modelling – Maximum Extent of Mixing Zone • Typical and “worst - case” seasonal scenarios considered; Golden Pheasant WWTP average and peak day flow conditions • Maximum extent of mixing zone defined by “worst - case: winter” scenario with long-term future (greater than 20-year planning period) peak day flow • Mixing zone to 1% concentration does not interact with IPZ-1 or shoreline Surface Layer Bottom Layer
Fairy Lake Dispersion Modelling – Ice Thickness Profiles (Typical Year) At location of proposed outfall Difference in Maximum Ice Thickness: 6 cm Difference in Daily Ice Thickness Maximum: 34 cm Average: 10 cm Ice Cover Duration: 8 fewer days
Summary of Outcomes 1. This project significantly reduces the environmental footprint on the Muskoka Watershed. 2. The reduction from two outfalls to one at a new location in Fairly Lake has no adverse environmental impacts. 3. The proposed plans meet all Provincial regulations as well as the upcoming Federal regulations. 4. The Capital project cost savings will be a minimum of $1,000,000. 5. The closure of Mountview Wastewater Treatment Plant and consolidation with the Golden Pheasant Wastewater Treatment Plant will result in significant operational and energy savings.
Sewage Works Improvements Town of Huntsville Mountview Wastewater Treatment Plant to Golden Pheasant Wastewater Treatment Plant Conveyance Strategy Public Information Centre (PIC) November r 29, , 2018
Recommend
More recommend
