City reviews final Casper Aquifer monitoring plan, staff to seek proposals and budget for implementation

The Laramie City Council on April 14 heard a final report from Trihydro proposing a Casper Aquifer monitoring network intended to establish baseline water‑level and water‑quality data, detect contaminants early, and identify sentinel wells to protect production wells.

The plan, presented by Trihydro project manager Ryan Athey and introduced by city water staffer Ben Plaven, recommends a network that combines about 13 source‑area wells sampled quarterly for two years and additional lower‑priority wells sampled less frequently. Athey said that the monitoring would track major cations and anions, total dissolved solids, metals, field parameters and nitrates — the latter already detected above the EPA maximum contaminant level of 10 mg/L in some locations — and that targeted suites (total petroleum hydrocarbons, pesticides) would be analyzed annually where appropriate.

Plaven said the program was included in the city's operating and capital budgets and that the city plans to solicit proposals for program implementation later this year, with a hoped‑for program start in 2027. “We did include this in our operating budget going forward to fund this program,” he told the council.

Why it matters: The Casper Aquifer supplies more than half of city domestic water in many areas and is a primary source during dry periods. Establishing consistent baseline sampling and sentinel wells aims to give the city advance warning of contaminants so production wells can be shut down or isolated before the drinking‑water supply is affected.

Key details: Trihydro emphasized that local fracture patterns and mapped faults control how contamination can migrate between the aquifer's lithologic members (alpha–epsilon). The firm proposed quarterly sampling of source‑area wells for two years to establish seasonality and trends, then cutting sampling frequency roughly in half after review of the initial dataset. Estimated costs: approximately $85,000 per year during the higher‑frequency baseline period and roughly $44,000 per year thereafter, excluding any additional new wells that may be drilled.

Councilors pressed on practical questions about sampling logistics and data management. Athey described hydro‑sleeve sampling methods as a cost‑effective approach for collecting representative samples and said the city could use a commercial data management system — “on the order of magnitude, it's probably a 10 to 20,000 dollar a year type of expense,” he said — or explore partnerships with the University of Wyoming for student support on data tasks.

Public input and next steps: During public comment, Sarah Gorin of Albany County Clean Water Advocates thanked the city, urged careful placement of monitoring wells to intercept likely flow paths, and asked whether the draft report would be released for public review. Plaven said staff and Trihydro will meet to determine a public comment process and bring the draft back to council for final adoption.

What the report recommends next: finalize the monitoring‑well network and implementation proposals, proceed with procurement for program implementation later in 2026, collect two years of higher‑frequency baseline data, then reassess well siting and sampling frequency based on results.

The council did not vote on a specific ordinance or contract at the meeting. The immediate next procedural step is staff's work to publish the draft report for public comment and to return to council with a proposed timeline for final adoption and procurement.