Taos council approves $438,058 purchase of cassette frames for wastewater membrane replacement

Taos City Council authorized purchase of cassette frames for phase 2 of the membrane replacement at the town’s wastewater treatment plant, approving proposal number 6115234, option 2, from OIA Water Technologies in the amount of $438,058.50 (exclusive of gross receipts tax).

Public works and Veolia representatives reported that a recent site visit found excessive wear on cassette frames and stainless-steel header manifolds. Staff said wear had progressed from plastic parts into the stainless-steel frames that house high-value membrane modules, increasing the risk of permeate contamination and premature membrane failure. "The cap capacity of the 2 membrane trains more than doubled with the newly installed modules," said staff during the presentation describing Phase 1 work; the new cassette frames are needed to support upcoming module installation.

Council received a multi-slide briefing describing the phased project. Phase 1 (modules for trains 3 and 4) was previously purchased and installed; in a recent site visit Veolia technicians attempted cassette refurbishment and found the frames too worn to rely on refurbishment alone. Staff showed photos of eroded cassette manifolds and explained that damaged manifolds can create holes that bypass filtration and destroy membranes. Operations staff noted heavy sludging, broken module headers and broken fibers in multiple trains; operators have performed interim repairs to salvage modules while the town works through a replacement plan.

The recommended purchase (option 2) is a hybrid approach: keep already-purchased plastic parts on hand and buy empty stainless-steel cassette frames for trains 1 and 2 and full cassette assemblies for trains 3 and 4. Staff said lead times for new cassettes are long and that having parts on hand will reduce future downtime. The presentation also identified a related screening problem at the plant: insufficient influent screening lets abrasive sands and debris into the bioreactor and accelerate wear. Staff said they are actively seeking new screening equipment and will address screening in parallel with cassette replacement.

The council motion to approve the procurement was made by Council Member Fambro and seconded by a fellow councilor; the roll call recorded unanimous support from those voting. Staff estimated overall project costs (membrane modules, cassettes, refurbishment and contingencies) at roughly $1.79 million for the full program and described next steps for scheduling installation to match module deliveries due later in the year.

Nut graf: The council approved an immediate procurement to protect the town’s recent membrane investment and to avoid premature system failure after Veolia engineers found structural wear that made refurbishment unsafe.

Ending: Staff said the new cassettes are expected to arrive in advance of some membrane modules; Veolia will assist with reassembly and installation once parts and modules are onsite. Councilors asked staff to keep them informed about screening improvements and schedule impacts.