La Marque council authorizes redesign, orders bids for wastewater plant after engineers recommend SBR to lower cost

The La Marque City Council on Oct. 28 authorized the city’s engineering team to revise plans for the wastewater treatment plant expansion using sequencing batch reactor (SBR) technology and directed the city manager and public‑works staff to put both the SBR and the original conventional design out to bid.

Adura engineers and city staff told council that the project—originally scoped in 2020 with roughly $35 million in combined funding—faces increased costs from supply‑chain inflation and a Texas GLO requirement to elevate equipment above the 100‑year floodplain. Adura representative Robert Vierra and project manager Rick (city staff/Adura liaison) said a conventional activated‑sludge design would likely come in at an estimated $36–$40 million, beyond available grant and loan funds; the SBR alternative reduces footprint and some equipment and concrete costs and was estimated by staff to save about $3–$4 million in capital costs.

“An SBR plant has a much smaller footprint and lower capital cost,” Adura staff said in the presentation, noting advantages including fewer clarifiers and smaller pumping and return systems. Engineers described SBR as the same activated‑sludge biological process packaged differently: “It’s the same process; it’s just happening in one basin versus two,” one presenter said.

Council members pressed for detail on durability, operation and permitting. Mayor Keith Bell said he wanted more public education on the change, asking, “I don’t know how many of our residents understood what you just described.” Staff replied that they had toured comparable facilities, met with TCEQ and GLO staff and believe the SBR approach is permissible and likely to meet treatment and permit requirements.

After discussion about timing and public outreach, Mayor Pro Tem moved to authorize Adura to prepare revised SBR plans and to direct the city manager and public‑works director to issue bid documents for the SBR design along with the conventional design so council can compare bids. The motion was seconded and carried by voice vote; staff said the redesign will take several months and construction would follow, likely a year to 18 months depending on lead times for equipment.

Next steps: Adura will complete revised design documents, staff will prepare bid packages for both alternatives, and council will receive and evaluate bids before making a final design and contract award. The council’s action authorized design and procurement steps; it did not adopt a final construction contract or change order.