Waste Water Treatment Plant Location Options Presented by: Ben Greenough, S uperintendent of Public Works Date: April 3, 2017 In Camera Meeting
S ewer S tudy Review 2010 S ewage Treatment and Disposal Feasibility S tudy 2013 Village/ S kidegate Band Joint S ewage Treatment Concept Design S tudy
Existing S ewer S ystem
Existing S ewer S ystem 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
Outfall The outfall at Pumping S tation No. 5 discharges sewage through an approx. 1200 m long 200 mm HDPE S eries 45 outfall The pipe is buried in a trench to j ust below the low tide mark and it then continues on the sea bottom to terminate at a depth of 20 m below low water
Treatment Plant S iting Criteria S hould 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
Treatment Plant S iting 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 S iting must consider the potential for odor and noise nuisance on the nearest residential or public use area The site must not impact archaeological sites
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” S equencing Batch Reactor technology has been selected for the treatment plant.
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 $)
Treatment Plant S ite Options Option 1: S mith Pt Option 2: Central Area Option 3: S kidegate Landing W Option 4: S kidegate Landing E
Treatment Plant S ite Options 1. S mith Point Area 2. Central Area 3. S kidegate Landing West Area 4. S kidegate Landing East Area 5. Joint treatment and disposal with the S kidegate Band Council
S mith Point Area PROS The required extension of the sewer system is minimum and the existing outfall can be used Existing Pump S tation 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 CONS 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
S mith Point Area
Central Area (Boat Launch) PROS Existing Pump S tation No. 5 can be re-used along with a 200 mm forcemain extension to the treatment plant The existing outfall at S mith 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 CONS 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
Central Area (Boat Launch)
S kidegate Landing West Area PROS A sit e near Haida Point is assumed and would allow for a new out fall t o be const ruct ed near Haida Point t o a 30 m dept h in S kidegat e Inlet The exist ing out fall would revert t o an emergency overflow st at us for Pump S t at ion No. 5 The t reat ment plant sit e is assumed t o be at a high enough elevat ion t o allow gravit y discharge of effluent t o t he out fall S it e would allow for sewer connect ion for maj orit y of municipalit y and open up propert y for pot ent ial development CONS The propert y t hat was viewed at t his t ime has since been sold and VQC does not own any propert y in t he area Finding a sit e t hat is sufficient ly large t o provide for even a “ small foot print ” t reat ment t echnology Not in an indust rial or agricult ural zoned locat ion Pump S t at ion No. 5 would be fit t ed wit h new pumps and a 200 mm forcemain will ext end 3.1 km from Pump S t at ion No. 5 t o t he t reat ment plant sit e Pot ent ial for odor, noise and nuisance on t he nearest resident ial and public use areas
S kidegate Landing West Area
S kidegate Landing East Area PROS A new outfall would be constructed near Image Point to discharge into 30 m of water in S kidegate Inlet The treatment plant site is assumed to be at a high enough elevation to allow gravity discharge of effluent to the outfall S ite would allow for sewer connection for maj ority of municipality and open up property for potential development The site is zone industrial CONS Finding a site that is sufficiently large to provide for even a “ small footprint” treatment technology VQC does not own property in this area S imilar to Option 3, Pump S tation 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
S kidegate Landing East Area
Joint Treatment With S kidegate
Joint Treatment With S kidegate In 2013, VQC engineers, Opus Dayton & Knight, worked with the S kidegate Band’s Engineers to come up with a study on how to connect VQC’s sewer system with the S kidegate WWTP The S tudy looked at: S everal options on how to connect the two systems Required upgrades to S kidegate’ s WWTP to handle the extra flow from VQC Required upgrades to S kidegate’ s outfall
Joint Treatment With S kidegate Conveyance system options
Joint Treatment With S kidegate: S kidegate 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 t ank, wit h aerat ion blowers A st and by generat or t o accommodat e t he expansion A well t o accommodat e a wat er service A headworks building wit h mechanical screen and flow measurement equipment
Joint Treatment With S kidegate: S kidegate WWTP Upgrades
Joint Treatment With S kidegate: 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
Joint Treatment With S kidegate: New Outfall
Joint Treatment With S kidegate: Overview
Joint Treatment With S kidegate: Considerations An agreement between VQC and the S kidegate 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
Joint Treatment With S kidegate: Considerations S ewage flow criteria S ewage quality criteria VQC and S BC responsibility for Permits, Approvals, etc. And so on…
Revised Estimates (2017 $) Option Study Estimate 2017 estimate 1. S mith Point $5,699,000 $6,838,800 2. Central Area $6,305,000 $7,566,000 3. S kidegate Landing West $7,158,000 $8,589,600 4. S kidegate Landing East $7,803,000 $9,363,600 5. Joint Treatment with S kidegate 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
Other Considerations: S ewer service Hook-ups
Recommend
More recommend
