Waste Water Treatment Plant Location Options. Presented by: Ben Greenough, Superintendent of Public Works Date: April 3, 2017 In Camera Meeting

Transcription

1 Waste Water Treatment Plant Location Options Presented by: Ben Greenough, Superintendent of Public Works Date: April 3, 2017 In Camera Meeting

2 Sewer Study Review 2010 Sewage Treatment and Disposal Feasibility Study 2013 Village/Skidegate Band Joint Sewage Treatment Concept Design Study

3 Existing Sewer System

4 Existing Sewer System Five pumping stations including the outfall pumping station The collection system comprises 150, 200 and 250 mm PVC pipe 1.2 km outfall discharges into bearskin bay approx. 20 m depth 403 residential and commercial service connections Does not provide sewer service to parts of the municipality

5 Outfall The outfall at Pumping Station No. 5 discharges sewage through an approx m long 200 mm HDPE Series 45 outfall The pipe is buried in a trench to just below the low tide mark and it then continues on the sea bottom to terminate at a depth of 20 m below low water

6 Treatment Plant Siting Criteria Should be isolated from residential development and public use areas - ideally within industrial or agricultural zoned land Based on a small footprint type of treatment plant the useable portion of the site should be about 0.11 ha in size for a long term population of 3,000; however, if a 30 m buffer area around the treatment units is added, the area requirement increases to 0.86 ha Long detention treatment such as aerated lagoons require considerably more area a minimum of 6.0 ha for 3,000 people, including a 30 m buffer zone

7 Treatment Plant Siting Criteria To minimize pumping, the site should be near sea level The outfall must be located in an area that provides good integration of the effluent into the seawater mass The outfall location must minimize impact on fisheries resources and recreational use of the water Siting must consider the potential for odor and noise nuisance on the nearest residential or public use area The site must not impact archaeological sites

8 Treatment Plant Concept Design For the purpose of this feasibility study, it has been assumed that a small site may be acquired for a Village owned treatment plant. A small footprint Sequencing Batch Reactor technology has been selected for the treatment plant.

9 Treatment Plant Concept Design Initial stage (1,250 people) capital and operation and maintenance (O&M) costs are detailed in Appendix 3 and summarized as follows: Capital Cost $4,550,000 (2010 $) O&M Cost $96,500/year (2010 $)

10 Treatment Plant Site Options Option 1: Smith Pt Option 2: Central Area Option 3: Skidegate Landing W Option 4: Skidegate Landing E

11 Treatment Plant Site Options 1.Smith Point Area 2.Central Area 3.Skidegate Landing West Area 4.Skidegate Landing East Area 5.Joint treatment and disposal with the Skidegate Band Council

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13 PROS CONS Smith Point Area The required extension of the sewer system is minimum and the existing outfall can be used Existing Pump Station No. 5 can be used to pump sewage to the treatment plant; however, an effluent pump station, and a section of land outfall would be needed at the treatment site to connect to the existing 200 mm marine outfall Finding a site that is sufficiently large to provide for even a small footprint treatment technology VQC does not own property in this area Not in an industrial or agricultural zoned location Potential for odor, noise and nuisance on the nearest residential and public use areas

14 Smith Point Area

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16 PROS CONS Central Area (Boat Launch) Existing Pump Station No. 5 can be re-used along with a 200 mm forcemain extension to the treatment plant The existing outfall at Smith Point can be used by pumping the treatment plant effluent in a 200 mm land section of outfall that is placed in the influent force main trench VQC owns property In this location Finding a site that is sufficiently large to provide for even a small footprint treatment technology The sewage collection system must be extended about 1.2 km to service a site in the Central Area Not in an industrial or agricultural zoned location Potential for odor, noise and nuisance on the nearest residential and public use areas

17 Central Area (Boat Launch)

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19 PROS Skidegate Landing West Area A site near Haida Point is assumed and would allow for a new outfall to be constructed near Haida Point to a 30 m depth in Skidegate Inlet The existing outfall would revert to an emergency overflow status for Pump Station No. 5 CONS The treatment plant site is assumed to be at a high enough elevation to allow gravity discharge of effluent to the outfall Site would allow for sewer connection for majority of municipality and open up property for potential development The property that was viewed at this time has since been sold and VQC does not own any property in the area Finding a site that is sufficiently large to provide for even a small footprint treatment technology Not in an industrial or agricultural zoned location Pump Station No. 5 would be fitted with new pumps and a 200 mm forcemain will extend 3.1 km from Pump Station No. 5 to the treatment plant site Potential for odor, noise and nuisance on the nearest residential and public use areas

20 Skidegate Landing West Area

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22 PROS CONS Skidegate Landing East Area A new outfall would be constructed near Image Point to discharge into 30 m of water in Skidegate Inlet The treatment plant site is assumed to be at a high enough elevation to allow gravity discharge of effluent to the outfall Site would allow for sewer connection for majority of municipality and open up property for potential development The site is zone industrial Finding a site that is sufficiently large to provide for even a small footprint treatment technology VQC does not own property in this area Similar to Option 3, Pump Station No. 5 will be fitted with new pumps and a new 200 mm forcemain will extend 4.2 km to discharge to the treatment plant

23 Skidegate Landing East Area

24 Joint Treatment With Skidegate

25 Joint Treatment With Skidegate In 2013, VQC engineers, Opus Dayton & Knight, worked with the Skidegate Band s Engineers to come up with a study on how to connect VQC s sewer system with the Skidegate WWTP The Study looked at: Several options on how to connect the two systems Required upgrades to Skidegate s WWTP to handle the extra flow from VQC Required upgrades to Skidegate s outfall

26 Joint Treatment With Skidegate Conveyance system options

27 Joint Treatment With Skidegate: Skidegate WWTP Upgrades The current WWTP is designed for a population of 1,250 people. This would need to be upgraded to support a population of 2,400 people and accommodate growth in both communities The proposed upgrades include: A new cement tank, with aeration blowers A stand by generator to accommodate the expansion A well to accommodate a water service A headworks building with mechanical screen and flow measurement equipment

28 Joint Treatment With Skidegate: Skidegate WWTP Upgrades

29 Joint Treatment With Skidegate: New Outfall A new outfall would be needed to service the design population of 2,400, as the existing marine outfall only has adequate capacity for 1,700 people The Option 3 and 4 conveyance system would require a new outfall to be located offshore from the sewage treatment plant The 200 mm outfall is marginally undersized for the design flow, so if a new outfall is selected, then it would be wise to install a 250 mm pipe because the cost difference is small while capacity would be substantially increased allowing for growth

30 Joint Treatment With Skidegate: New Outfall

31 Joint Treatment With Skidegate: Overview

32 Joint Treatment With Skidegate: Considerations An agreement between VQC and the Skidegate Band Council would have to be negotiated and include: Ownership and cost sharing for the sewage conveyance system, both existing and new works Cost sharing for the existing treatment plant and the expanded treatment plant, assuming Band ownership Cost sharing for the new outfall, assuming Band ownership Design and construction responsibility for new works

33 Joint Treatment With Skidegate: Considerations Sewage flow criteria Sewage quality criteria VQC and SBC responsibility for Permits, Approvals, etc. And so on

34 Revised Estimates (2017 $) Option Study Estimate 2017 estimate 1. Smith Point $5,699,000 $6,838, Central Area $6,305,000 $7,566, Skidegate Landing West $7,158,000 $8,589, Skidegate Landing East $7,803,000 $9,363, Joint Treatment with Skidegate Band $11,800,000 $13,216,000 *added 20% to 2010 Study estimates 1 to 4, and 12% to 2013 Study estimate 5 to account for years of inflation

35 Other Considerations: Sewer service Hook-ups

36 Other Considerations: Sewer service Hook-ups Approximately 60 sewer service connections are not on the existing system A gravity collection system and pumping stations would need to be installed to include them No pricing was completed on this aspect Could add $3 to $4 million dollars in expense, but more engineering is required to develop an estimate

37 Other considerations: Water System Extension If construction on a sewer main is going to happen, Council should consider extending the water system at the same time A chlorine booster station would be required, and possibly another reservoir A quote of $1,191,750 to extend the Water Main to Skidegate landing was developed in 2009 More engineering would be required to develop a more comprehensive and updated cost estimate

38 Next Steps: Decide on a Location Council will need to make a decision on where to locate a Waste Water Treatment facility: This must include public consultation Archeological assessment may be required May need to look at purchasing or expropriating property depending on the decision

39 Next Steps: Engineering After a location is decided upon engineers can then develop a design for a system Treatment options can be reviewed at that time Grant Funding will most likely be required to complete this stage Multiple permits will be required for this project

40 Next Steps: Construction After the design is complete and permits are obtained, construction can begin Multiple funding sources will be required for this Construction would be completed in several phases This project will span several years (for example the Honna Water Treatment Plant project took 10 years from conception to completion)