Iqaluit, Nunavut
THE CHALLENGES WITH MECHANICAL WASTEWATER TREATMENT SYSTEMS IN THE NORTH Ken Johnson Engineer, Planner, and Historian
Carmacks, Yukon
The Challenges with Mechanical Wastewater Treatments Systems in the North
4000 km
3000 km
Mechanical treatment facility locations in the North
The Challenges with Mechanical Wastewater Treatments Systems in the North
Introduction to northern wastewater treatment
12 week period
Trucked sewage (BOD/TSS 400 mg/L; Ammonia 30 mg/L)
The Challenges with Mechanical Wastewater Treatments Systems in the North
Performance of Lagoon Systems
Whitehorse sewage lagoon system is the largest facility of its kind in northern Canada serving a population of 24,000 and producing a very high quality effluent, which is well below the Wastewater Systems Effluent Regulations.
The Challenges with Mechanical Wastewater Treatments Systems in the North
Challenges with Lagoon Systems
The lagoon systems in a number of communities in the Nunavut Territory have issues associated with stability and seepage – these issues and other research is demanding a rethinking of the performance of lagoons in the high arctic given the influent quality (pure sewage) and environmental impact (minimal impact).
The Challenges with Mechanical Wastewater Treatments Systems in the North
Pangnirtung, Nunavut – secondary treatment Sludge bagging
Process – rotating biological contactor (RBC) History – commissioned in 2004 Performance – not meeting licence criteria Construction – design / tender / construct
Effluent discharge
The Challenges with Mechanical Wastewater Treatments Systems in the North
Pangnirtung, Nunavut – secondary treatment
New process building
New process tank
Challenges – RBC installation suffered multiple mechanical failures, including shaft breaking Successes – Retrofitting of facility has been successful within the same building envelope Future – MBR retrofit completed on the facility in 2015; experiencing foaming problems
The Challenges with Mechanical Wastewater Treatments Systems in the North
Iqaluit, Nunavut – secondary treatment Iqaluit wwtp discharge Uncommissioned wwtp in Iqaluit (2004)
Process – membrane bioreactor (MBR) History – completed 2000, but never commissioned Performance – not meeting licence criteria Construction – design / build
The Challenges with Mechanical Wastewater Treatments Systems in the North
Iqaluit, Nunavut – secondary treatment
Phase 2 bioreactors to be retrofitted from original MBR bioreactor construction clarifiers will be constructed as a new addition to the existing buildings
Construction of phase 1 of rehabilitation work in 2005
Challenges – negotiation with original MBR design builder to advance commissioning (never advanced); independent inspection identified multiple serious deficiencies in building systems Successes – design for rehabilitation executed with opportunity to utilize existing building envelope
The Challenges with Mechanical Wastewater Treatments Systems in the North
Iqaluit, Nunavut – secondary treatment
Phase 2 Bioreactors (retrofit construction)
Phase 2 Clarifiers
Phase 1 Primary (complete)
(new construction)
Construction of phase 1 of rehabilitation work in 2005
Future – phase 2 rehabilitation construction anticipated to be completed by 2018, including retrofit of aeration basins and addition of clarifier building for MBBR process.
The Challenges with Mechanical Wastewater Treatments Systems in the North
Rankin Inlet, Nunavut – primary treatment
Rotating drum filter To Discharge
Process – rotating drum filter History – commissioned in 1996 Performance – not meeting licence criteria Construction – design / tender / construct
The Challenges with Mechanical Wastewater Treatments Systems in the North
Rankin Inlet, Nunavut – primary treatment
Rotating drum filter
Effluent discharge into Hudson Bay
Challenges – drum screen periodically plugged with debris causing flooding of building; regulators continued to push for secondary treatment Successes – provided increment solution to unacceptable raw sewage discharge Future – design for secondary treatment complete and project tendered
The Challenges with Mechanical Wastewater Treatments Systems in the North
Fort Simpson, NWT – secondary treatment Biofilter
Process – physical / biological system (Proteus Environmental Systems Ltd proprietary system) History – commissioned in 2002 Performance – not meeting licence criteria Construction – design / build
Grit trap and clarifier
The Challenges with Mechanical Wastewater Treatments Systems in the North
Fort Simpson, NWT – secondary treatment New SBR system
Challenges – Ft Simpsons is under regulatory directive for sewage improvements; proprietary system has never operated satisfactorily Successes – improvements have been undertaken within original building envelope Future – design complete and construction planned for new SBR system.
The Challenges with Mechanical Wastewater Treatments Systems in the North
Carmacks, Yukon – secondary treatment
Interior of Carmacks wwtp
Process – extended aeration activated sludge History – commissioned in 2009 Performance – meeting licence criteria Construction – supply / installation for process and design / tender / construct for building
The Challenges with Mechanical Wastewater Treatments Systems in the North
Carmacks, Yukon – secondary treatment Wet well
Pumping raw wastewater
Challenges – the design and construction work was executed on a piecemeal basis , which caused coordination issues, additional costs, and significant deficiencies Successes – the effluent quality is within the regulatory limits; the facility replaced a facility commissioned in 1975 and was at end of design life Future – correction of deficiencies and additional documentation for standard operating practices will be produced
The Challenges with Mechanical Wastewater Treatments Systems in the North
Dawson City, Yukon – secondary treatment Dawson wwtp (without roof)
Process – deep shaft aeration with flotation clarification History – start up in August 2012 Performance – not meeting licence criteria Drill mud recycling for construction of two 100 deep shafts Construction – design / build
The Challenges with Mechanical Wastewater Treatments Systems in the North
Dawson City, Yukon – secondary treatment Sewage discharge in Dawson circa 1975
Dawson ww screening plant was replaced by deep shaft facility
Challenges – Dawson City under court order for completion of wwtp; over $30 million has been spent on wwtp related work in past 10 years; construction challenges on project Successes – new wwtp has ended a 30 year dispute over secondary treatment in Dawson Future – the process continues to have operating difficulties and construction deficiencies
The Challenges with Mechanical Wastewater Treatments Systems in the North
Issues observed in various projects Regulatory framework – several northern wwtp projects have advanced based upon “regulatory threats” rather than definitive regulatory framework or regulatory directives – EXAMPLE: the Town of Iqaluit advanced a design build proposal for a secondary treatment system in 1997 based upon a “regulatory threat”. Dawson wwtp construction
Process selection – the north is not an appropriate testing realm for new technologies or technologies that do not have a ”track record” of performance – EXAMPLE: the Town of Iqaluit advanced a membrane bioreactor process when the application of the technology was just being introduced in southern Canada.
The Challenges with Mechanical Wastewater Treatments Systems in the North
Issues observed in various projects Consultant experience – the consulting resources applied to a wwtp project should have the appropriate northern experience and expertise – EXAMPLE: the majority of the designer’s experience on concrete aeration basins for the Iqaluit wwtp was associated with concrete residential building foundations in the Okanagan region of British Columbia. Contractor experience – the contracting resources applied to a wwtp project should have the appropriate northern experience and expertise – EXAMPLE the design build contractors for the Fort Simpson and Dawson wwtp had never completed a project of a similar of size and scope in the north. Dawson wwtp construction
The Challenges with Mechanical Wastewater Treatments Systems in the North
Issues observed in various projects Contract framework – effort up front in the development of a comprehensive contract pays off later on – EXAMPLE: the Town of Iqaluit executed the initial part of the work without a signed contract, using simple service contracts to advance the administration for payment. Executed contract – in spite of the most comprehensive contract prepared in advance of a project, the poor execution of the contract itself can effect the outcome of a project – EXAMPLE: the executed contract for Dawson City had a typographical error which allowed the contractor an additional year to complete the work. Dawson wwtp construction
The Challenges with Mechanical Wastewater Treatments Systems in the North
Issues observed in various projects Materials prepared on site – materials prepared on site, for example concrete, are a potential source of problems – EXAMPLE: poor concrete on the Dawson City wwtp has jeopardized the design life of the project . Contract administration – resources should be in place to provide comprehensive contract administration from beginning to end of the wwtp project – EXAMPLE the Town of Iqaluit did not retain an owner’s representative until well over a year after the construction began.
Dawson wwtp construction
The Challenges with Mechanical Wastewater Treatments Systems in the North
Issues observed in various projects Access and weather – since the beginning of modern development over a century ago, the north has been a challenging environment for access and weather related challenges – this has not changed for the most part – EXAMPLE: locations such as Dawson City still remain a challenge for easy access. Material transportation – material transportation in the north is challenge for scheduling and material integrity – EXAMPLE: the process tankage for Carmacks fell off the truck during transportation jeopardizing the commissioning of the project.
Dawson wwtp construction
The Challenges with Mechanical Wastewater Treatments Systems in the North
Issues observed in various projects Operation and maintenance – operation and maintenance considerations of a facility should begin at the same time as the process design – EXAMPLE: Dawson City facility process is still not successfully operational after 36 months. Operation and maintenance documentation – operation and maintenance documentation should be a well defined part of the contract with a clear standard for appropriate content, and significant monetary milestones for delivery – EXAMPLE: operation and maintenance documentation often received at the end of a project is an assembly of “cut and paste” information with limited project specific information.
Dawson wwtp construction
The Challenges with Mechanical Wastewater Treatments Systems in the North
Issues observed in various projects Training and staffing – training and staffing consideration of a facility should be begin at the same time as the process design – EXAMPLE: Dawson City staff are not yet fully trained to operate the facility.
Add figure
Dawson wwtp construction
The Challenges with Mechanical Wastewater Treatments Systems in the North
Is there a recipe for success ? Each and every project in the north is unique, so there is no recipe for success, however with the communication of project experiences, the potential list of things that can go wrong when the project team is in play may be greatly reduced.
The Challenges with Mechanical Wastewater Treatments Systems in the North
Questions ? SEND ANY QUESTIONS TO ken.johnson@cryofront.com For more information www.issuu.com/cryofront www.issuu.com/pereletok www.youtube.com/cryofront