Wastewater

Objectives

  • Provide regional approaches to wastewater treatment and disposal that protect human health and the natural environment
  • Coordinate the planning of wastewater infrastructure to support efficient patterns of regional development
  • Minimize wastewater infrastructure costs through coordination between municipalities
  • Support the planning and development of a second wastewater treatment plant to provide for regional needs
  • Promote measures to reduce wastewater production rates per capita across the P4G Region and extend the capacity of infrastructure

 

Context

A summary map for the regional wastewater system is provided in Exhibit 2. Key elements of the system include:

    • Saskatoon Wastewater Treatment Plant. The current City of Saskatoon Wastewater Treatment Plant (WWTP) provides wastewater treatment for the City, and may be expected to service the City of Martensville through a joint servicing agreement that is currently under negotiation. The current capacity of the plant is rated at 120 ML/d of average daily flow, with a peak daily flow of 216 ML/d, and a peak hourly wet weather flow of 300 ML/d. The City has outlined a long-term capital investment schedule to improve capacities over the long term, and the current site will be able to accommodate a maximum average daily flow capacity of 170 ML/d.
    • Urban municipal treatment facilities. The smaller urban municipalities in the P4G Region use lagoon treatment systems to support local wastewater servicing. The capacities of these facilities, including treatment and storage, are as follows:

 

      • Martensville: approximately 13,000 residents
      • Warman: approximately 14,000 residents
      • Osler: approximately 2,000 residents

 

The Osler lagoon is located outside of the P4G Region, as noted on the map in Exhibit 2.

  • Conceptual Martensville-Saskatoon connection. As noted in the potable water section, a memorandum of understanding between Saskatoon and Martensville may establish a major sewer connection to the Saskatoon wastewater system. This alignment has not been finalized, but would connect with the existing network in the short term, and use the current Martensville lagoon for storage and limited treatment.
  • Future concepts for regional wastewater collection and treatment. Regional pipeline connections between Saskatoon and the other urban municipalities in the P4G Region would allow for efficient sharing of capacity, and delay the need to build additional treatment capacity elsewhere in the P4G Region. Conceptual alignments for these connections have been noted on the map, but will be contingent on future planning and coordination.
  • Rural lagoons and on-site systems. In addition to the municipal wastewater collection systems noted on the map, rural lagoons and other on-site systems provide for wastewater collection and treatment in rural areas.

 

Servicing Extensions

Planning major sewer main alignments is a primary concern for regional wastewater collection and treatment. The following considerations will need to be made in development and sequencing with respect to wastewater servicing (with numbered areas corresponding to the annotations on the context map in Exhibit 2):

    • Topography challenges for local servicing. The topography of the P4G Region is a challenge for wastewater collection as it does not provide the necessary slope to allow for wastewater drainage by gravity in all areas. Forcemains would be required to pump wastewater from certain flat and low-lying areas to treatment facilities, which would increase costs. This would primarily include part or all of the following areas within the current system:

 

      • Area 1: Saskatoon Northwest
      • Area 3: Martensville West
      • Area 4: Martensville/Warman
      • Area 6: Saskatoon Highway 11
      • Area 9: Grasswood/Saskatoon South
      • Area 10: Corman Park South

 

  • Limitations to Saskatoon servicing capacity in the east. Although areas to the east and south of Saskatoon (Areas 7–9) present opportunities for wastewater collection from gravity drainage, the capacity of the Saskatoon wastewater system to make direct connections to future urban growth areas is limited east of Preston Avenue. This is due to the size of the current sewer mains and trunk lines. Because of this, the wastewater collection system in these areas will need to be connected in the north (around Area 7), and link to either the proposed new river crossing at the current WWTP, or be directed to a new treatment facility in the P4G Region . This will strongly impact the desirable sequencing of development, as development along new sewer mains may need to start in the northeast and proceed south, instead of extending directly east.
  • Coordination of infrastructure for the Agri-Food Node. The Town of Osler and RM of Corman Park have discussed developing an Agri-Food Node, generally located around Area 5 (Warman-Osler). Support of value-added businesses related to agriculture should consider the wastewater servicing needs of this area, including potential for higher organic and contaminant loadings into the wastewater treatment system and capital costs for new infrastructure.
  • Coordination with First Nations. For many First Nations in the P4G Region, limitations to wastewater servicing provides the major limitation to development and productive use of treaty land entitlements (TLEs) and reserve lands. Cost-sharing agreements between First Nations and municipalities can help extend services to these locations, and provide greater opportunities for housing and economic development.
  • Ongoing needs for on-site treatment. Although the Servicing Strategy will strive to coordinate long-term regional infrastructure, the need for on-site treatment solutions will continue as rural development occurs.

 

Regional Treatment Capacity

An assessment of estimated regional wastewater flows is provided in Appendix C, including projections of long-term wastewater generation. From these flow projections, the following conclusions can be reached:

  • Upgrades are required for meeting Saskatoon capacity needs alone. Additional upgrades to the Saskatoon WWTP, which has a current capacity of 120 ML/d for average daily flow, are expected to be required by 2024–2033 to accommodate Saskatoon alone.
  • Managing regional wastewater would require allocation of some capacity by Saskatoon.Capacity of the Saskatoon WWTP will be reached earlier if some or all of the urban municipalities in the P4G Region are connected to the WWTP. This may be minimized by maintaining lagoons for wastewater storage in these communities, and providing for off-peak treatment by the WWTP. However, the additional flows will contribute to a more immediate need for plant expansions.
  • Capacity needs of the smaller urban municipalities are more immediate. Although the measures of lagoon capacity for Warman, Martensville, and Osler are harder to fix to a specific timeline given changes in population growth and an uncertain split between commercial and residential uses, there are immediate needs for new capacity, especially in Warman and Martensville. This has been recognized as part of the ongoing discussions about Saskatoon-Martensville water and wastewater connections, but further regional growth may be constrained without a solution within the next 5–10 years.
  • A second regional wastewater treatment plant will likely be required in the long-term. The capacity of a full build-out of the existing Saskatoon WWTP site (170 ML/d) would support Saskatoon alone until 2038–2050, and all urban municipalities over a slightly shorter period. Unless further capacity expansion is possible, a second treatment option, likely coordinated at a regional level, will be required.

 

Regional System Connections

Providing for connections between municipalities as part of a regional wastewater collection and treatment system would be ideal in addressing several issues, including:

  • Short-term requirements to increase wastewater treatment capacity available to Warman and Martensville in a cost-efficient way
  • Longer-term requirements for additional capacity for all municipalities through an additional WWTP
  • Urban municipalities with immediate needs for additional treatment capacity within the next 5–10 years (e.g., Warman and Martensville) versus communities with longer-term needs for new or expanded facilities (e.g. Saskatoon and Osler)
  • Increased treatment effluent quality, according to both current requirements and potential future regulations
  • Challenges in local servicing over a wider area, including areas not possible to accommodate within current systems as noted above

 

A phased approach with specific short-term and long-term options will need to be considered and studied by P4G in the future as regional planning for infrastructure is implemented. As part of this Servicing Strategy, the following options have been provided to build the components of a regional system.

Short-Term Regional System

Within the short-term (within the next 20 years), the following steps should be explored by P4G to support a regional wastewater system:

  • Saskatoon-Martensville connection. A Saskatoon-Martensville pipeline may be constructed to link the Martensville wastewater collection system with Saskatoon to address treatment capacity limitations. This system would provide for off-peak pumping and treatment by the Saskatoon wastewater system to minimize impacts to available capacity. This option is currently being reviewed by the two municipalities, and should be supported by P4G as a step towards regional capacity sharing.
  • Highway 11 corridor wastewater pipeline. To accommodate wastewater flows from Warman into the Saskatoon wastewater collection system, a forcemain may be constructed to link the communities as shown in Exhibit 2. It is likely that the existing lagoon would remain for storage and emergency treatment capacity as with the Martensville connection. The Osler system would be able to connect into this pipeline as well, although the need for this capacity would not be immediate.
  • Expanded Warman treatment facilities. A second option would be to provide new or expanded treatment facilities closer to Warman and Osler, as shown in Exhibit 2. Given the land requirements and expected growth of Warman into the future, the preferred option would be to construct a small WWTP that would replace the facultative lagoon. Although it may be possible to expand this facility later into a regional WWTP (as noted below), accommodating future expansions would likely require high up-front costs for the plant.The recommended options in this case would include developing Martensville and Warman pipelines to allow for the use of the Saskatoon WWTP capacity, and accommodating additional regional capacity through the Saskatoon plant only. This would require a significant policy change to the City of Saskatoon, to shift its role to one as a regional service provider for wastewater treatment. The options provided here should be explored further to provide more detailed costing information and likely regional and local investments required.

 

Long-Term Regional System

For the long term (20 years and later), the development of a new wastewater treatment plant will be the primary focus of a regional system. The development of a second WWTP should be triggered before Saskatoon exceeds the maximum capacity of the existing WWTP by 2037–2048. This increased plant capacity would be expected to accommodate Warman, Osler, and Martensville, as well as growth areas in certain parts of Saskatoon.

Considerations for this project include the following:

  • Location of the WWTP. Potential sites for wastewater effluent disposal into the South Saskatchewan River are significantly constrained. The development of country residential subdivisions along the River will preclude siting in these areas, and sites within the City of Saskatoon are limited. Developing the WWTP further downstream will bring the facility closer to the smaller urban municipalities, but will require realignment of the regional pipeline network and would be further from the urban development to be serviced.
  • Management of the WWTP. When a second WWTP is required, the management of the plant would need to be determined. This may include a role for P4G, potentially as a Planning Authority.
  • Design of pipeline system. The location of the plant will strongly impact the configuration of the system. A facility further downstream, for example, would require the construction of longer regional pipelines, but would allow for regional gravity drainage to the new plant. Building new facilities within Saskatoon would require more forcemain systems for wastewater collection, but would keep the facility closer to significant urban growth.
  • Capital funding. Although a new regional plant may be managed like an expansion of the current Saskatoon system, a partnership with other municipalities would provide additional resources and options for developing the facility. A regional development levy could provide additional funding for the development and construction of the WWTP, for example, and the P4G as a common lobbying bloc could help to secure federal and provincial funding.
  • Management of capacity. If a regional facility was to be developed as a joint project, a concern would be the allocation of capacity between the partners, especially if different communities would grow at different rates than expected. This would also conflict with the current City of Saskatoon policy of only allocating surplus capacity to other jurisdictions. Clear agreements would need to be developed to tie in capacity management with expectations of the timing and nature of development under the Regional Plan.

 

Although the need for additional treatment capacity in the long-term is clear, planning for a new facility will be strongly dependent on the type and rate of growth experienced over the next decades, as well as the regional capacity developed to manage large projects such as these and the long-term objectives of each individual community. To this end, more detailed planning and fiscal assessments of different options for a regional wastewater treatment plant should be coordinated to provide a clearer understanding of preferred alternatives.

Regional Actions

Considering the current regional context and projected needs for wastewater collection and treatment, P4G should pursue the following actions:

  • Develop a Regional Wastewater Servicing Study and Plan. P4G should work to develop a Regional Wastewater Servicing Plan to provide clear guidance regarding intended regional actions in developing a regional wastewater system. This Plan should be developed after a full study is conducted to provide a clearer understanding of the costs and benefits of regional options, and provide a strong policy direction for future work by P4G and the municipalities.
  • Support cost-effective expansion of local servicing. To reduce overall servicing costs, development in the P4G Region should be encouraged to consider challenges and limitations with wastewater collection and treatment. The focus of new development in communities should be on areas which will be more cost-effective to service, including areas that can employ gravity drainage collection systems.
  • Promote the economies of scale in developing a regional wastewater system. P4G shall support the development of shared wastewater treatment systems between Martensville and Saskatoon, and Warman and Osler. These systems should be coordinated initially as bilateral or multilateral municipal agreements, and established to provide a foundation for a region-wide wastewater system. In the short-term, P4G may function as a coordinating body for these projects, but may be more involved with the development and management of the regional system in the long term, especially if P4G transitions to an Authority model.
  • Address immediate treatment capacity needs in municipal systems. There is a critical need to expand treatment capacity in Martensville and Warman to meet regulatory guidelines and address future population growth. Martensville and Saskatoon are currently in negotiations to link Martensville to the Saskatoon system. Warman should look to develop a joint approach that includes the development of a pipeline to the Saskatoon system as well, and Osler may elect to link to this network to provide longer-term solutions for their own capacity needs.
  • Address requirements for large industrial customers. Potential industrial customers of the regional wastewater system may require sufficient capacity in the system. This may include users such as food-related industrial operations and value-added agri-businesses. Planning as part of a regional system should work to coordinate these needs with long-term allocation of infrastructure.
  • Coordinate planning for a second regional wastewater treatment plant and associated pipelines. A second wastewater treatment plant will be required once the capacity of the Saskatoon WWTP is reached. Planning should be coordinated at a regional level, and the preliminary siting, design, and fiscal analysis of this plant should be conducted as soon as possible to identify any required steps to be carried out by P4G in the short-term. These steps should include the protection of a site, including development of setbacks to discourage incompatible uses, and coordination of financing options for funding the project.
  • Regional wastewater sewer use bylaw. As a regional system for wastewater collection and treatment is coordinated, it will be necessary to ensure that different communities are applying the same standards to their wastewater collection systems. P4G should coordinate between jurisdictions to ensure that any necessary bylaws and policies are passed to align these standards on a regional basis.
  • Explore cost-sharing relationships with other partners for servicing extensions, including First Nations. The development of a regional system will involve additional partners aside from P4G members. Several First Nations have land holdings in areas which will require servicing with major trunk lines and new treatment facilities, and these services can support greater development opportunities on these lands. P4G should work to engage with these partners to discuss these arrangements.