Utilities seek $505,000 to dredge Ditch 1 to restore wastewater treatment capacity

City utilities requested council support to dredge Ditch 1 at the Bob Darrington Water Reclamation Plant after a sonar survey identified about 4,400 cubic yards of accumulated grit that is reducing treatment capacity. Alex, speaking for the utilities department, said grit — heavy particles such as sand and gravel — is abrasive, shortens equipment life and reduces detention time needed for biological treatment. Utilities staff said their calculations indicate the plant needs about 45% more oxygen in the ditch to treat influent effectively and that removing grit will restore detention and treatment capacity. The work follows nearly $3.0 million in improvements to the plant’s grit removal system, funded with ARPA dollars, and will use a contractor on the city’s TIPS (Texas Interlocal Purchasing System) contract. The estimated cost including a 10% contingency is $505,000; funding is available in the wastewater repair-and-replace budget for fiscal year 2025. Utilities estimated completion in 63 calendar days. The project description says the contractor would excavate and remove grit, process it, and return organic solids beneficial to treatment back to the system while disposing of the grit removed. Council members asked clarifying questions and were told the work is necessary to improve treatment performance and aid TCEQ compliance. Staff said the project will be managed through existing procurement channels and funded from the wastewater R&R budget.