Minnetrista City Council weighs water-treatment plant designs, financing and rate options

Minnetrista City Council held a work session Feb. 3 to review design, cost and financing options for a proposed water treatment plant intended to expand capacity and provide redundancy for the city’s southern water system.

Council members and city staff focused on three primary design options presented by staff: (1) a full concrete gravity filter plant with a roughly 600,000‑gallon below‑grade clear well and about 2,200 gallons‑per‑minute (gpm) treatment capacity (the project staff has generally budgeted at approximately $26.3 million); (2) a gravity steel‑filter option that would retain a clear well but reduce construction cost relative to full concrete filters; and (3) a pressure‑filter option without a separate clear well that would reduce upfront cost but likely require earlier construction of an elevated storage tank (water tower) to meet future storage and peak‑hour needs.

Why it matters: the project is large enough to affect utility rates, billing practices and long‑term city finances. Staff and council discussed whether to seek state bonding and how state funding conditions (including prevailing‑wage requirements) could change project costs; they also explored rate structures such as a dedicated debt service line item on utility bills, monthly billing, and tier spreads intended to influence customer water use.

Key details and discussion points

- Project scope and cost estimates: Staff described the “Option 1” concept (concrete gravity filters plus a ~600,000‑gallon clear well) as the baseline the council has been planning toward, with a current planning estimate in the mid‑$20 million range. Staff and a contractor contact said steel filter designs and other bid alternates could reduce the total cost by varying amounts, with early contractor comparisons suggesting possible savings in the low millions depending on the filter type and whether the clear well is included.

- Storage, redundancy and timing: The clear well was discussed as a way to provide short‑term stored treated water and operational redundancy (for example, to allow taking existing tanks offline for repainting or repairs). Council members repeatedly raised the question of whether the city would be overbuilding for projected growth (and thus paying untimely debt service) versus underbuilding and having to add a water tower or other storage sooner.

- Capacity and growth assumptions: Staff reported the system currently serves roughly 2,200 accounts and noted the plant sizing conversations are tied to growth projections (one referenced planning numbers that would push major additional treatment needs decades into the future under moderate growth assumptions). Councilmembers pressed staff to show how many new homes the different options would support and emphasized the financial risk if growth does not materialize at projected rates.

- Financing and bonding: Staff said the city has a bonding request in the legislature (staff quoted a current request figure of about $26,000,300 to the state). Council discussed the effect of accepting state bonding dollars — specifically that state funding would trigger state prevailing‑wage rules and could change overall project cost compared with all‑city financed scenarios. Staff noted that bond structures (for example, back‑loaded debt service or longer terms) can be used to smooth near‑term rate increases but increase total interest cost.

- Rate design and billing: Council discussed alternatives to absorb the project cost without dramatic per‑unit rate spikes. Staff outlined options including: (a) adding a dedicated monthly or quarterly debt‑service line item to every account so each account contributes a fixed amount toward the plant; (b) changing from quarterly to monthly billing to reduce customer bill volatility and call volume to utility staff; and (c) increasing the spread between usage tiers so high‑volume users face stronger price incentives to conserve. Staff provided rough illustrations: using a hypothetical $30 million bond, annual debt service could approximate $2.2 million (about $1,000 per account per year if spread evenly across 2,200 accounts), and a debt‑service fee in the low hundreds of dollars per quarter was used as an example in the discussion to show scale and comparison with neighboring towns.

- Deliverables and next steps: Council asked staff to obtain more detailed contractor or bid‑level estimates and to develop bid alternates so the city can compare (a) concrete gravity filters with clear well, (b) steel gravity filters with clear well, and (c) smaller initial filter sets (two filters) with a planned expansion space to add filters later. The group generally agreed to retain the roughly 600,000‑gallon clear well in analyses that will be returned to council. Staff said they will prepare refined cost figures, amortization schedules, and rate‑impact scenarios and return at a later meeting; staff also noted the legislature’s bonding timetable as a factor in the procurement schedule.

What the council did and did not decide

- Discussion only, not a final selection: The council did not vote to select a final design or award a contract. The meeting produced a direction to staff to produce more granular cost and bid‑alternate information for the options discussed (including steel vs. concrete filters, two‑filter vs. four‑filter starting configurations, and cost comparisons with and without a clear well).

- Administrative action: The council voted to adjourn the work session at the meeting’s close (motion moved and seconded; all those present signified “aye”).

Next steps and timing

City staff will solicit contractor estimates or task‑order pricing to develop bid‑level cost comparisons, refine amortization and rate‑impact tables, and return to the council with those numbers. Staff noted key external timing constraints: the state bonding calendar and the local bidding schedule could affect the city’s ability to award contracts during the current legislative session window. The council scheduled follow‑up discussion at a later work session to review the contractor estimates and the revised rate impact scenarios.