About the Report
The 2015 Minnesota Legislature directed the Minnesota Department of Natural Resources (DNR) to prepare cost estimates for augmenting White Bear Lake with Mississippi River water taken from the Sucker Lake Chain of Lakes. St. Paul Regional Water Services brings Mississippi River water through the Sucker Lake Chain as part of its drinking water supply system.
The DNR worked with the Metropolitan Council to hire Short Elliott Hendrickson (SEH), a consulting/engineering firm, to conduct an analysis and prepare a report on the cost of moving water from the Sucker Lake Chain to White Bear Lake. Additional firms provided independent technical review of SEH's work. The DNR has confidence that the SEH analysis and report provides an accurate concept-level cost estimate for augmenting White Bear Lake.
The report was delivered to the Legislature on January 29, 2016.
Report
- Concept Cost Report for Augmentation of White Bear Lake with Surface Water
- Concept Cost Report Appendices
Two Pipeline Alternatives
Short Elliott Hendrickson prepared cost estimates for two pipeline alternatives: the Sucker Lake alternative and the East Vadnais Lake alternative. Both lakes are located in Vadnais Heights, Minnesota, approximately four miles west of White Bear Lake. Both alignment alternatives were assumed to have similar infrastructure systems, and include limited water treatment to remove aquatic invasive species (including zebra mussels) and solid particles. SEH also prepared cost estimates for two additional water treatment options that would achieve higher levels of water quality treatment.
Cost Estimates
The estimated costs for construction, basic water treatment, and annual operations and maintenance are summarized below. The Sucker Lake alternative has a higher construction cost because a 1,600 foot tunnel would need to be built under I-35E and the alignment has more contaminated sites and poorer soils for construction. The estimates are based on construction occurring between 2018 and 2019.
Estimated Cost | Sucker Lake Alternative | East Vadnais Lake Alternative |
Construction Cost | $67 million | $55 million |
Operations and Maintenance Cost | $570,000 / year | $570,000 / year |
Additional Water Treatment
In order to meet water quality standards and goals, it may be necessary to employ advanced water treatment beyond the basic filtration system included in the cost estimates. The higher levels of phosphorus in the Mississippi River and the Sucker Lake Chain relative to White Bear Lake are a particular concern. Phosphorus is a nutrient that, in excessive concentrations, can cause algal blooms, loss of water clarity, and other adverse water quality impacts. To achieve higher levels of water treatment, capital costs could increase by $23-$40 million, depending on the treatment technology selected. This would put total construction costs at $78-$107 million, depending on the alignment and treatment technology. Adding this additional water treatment could also increase operation and maintenance costs to $900,000 to $4.1 million per year.
Cost Uncertainties
There are still uncertainties that could increase or decrease the capital and annual operating cost estimates, including the level of water quality treatment needed, unknown underground conditions (e.g., soils, groundwater levels, boundaries of contamination and location of existing utilities), the amount of water pumped each year, changes in design assumptions such as the system capacity, and selection of a different or modified pipeline route.
Questions
Questions regarding the report, contact Jason Moeckel at [email protected] or 651-259-5240.