To help maintain compliance with current water quality requirements and address risks of failure due to age and condition, the team replaced the influent bar screens and conveyor, the grit removal system, the biological process air supply system, internal recycle pumps, and one of the two secondary clarifiers. To comply with increasingly stringent fecal coliform limits in plant effluent, the team renovated the ultraviolet (UV) disinfection system with new technology to provide a higher level of treatment and increased reliability; it also enabled the system to reach the operational stage faster. To allow the plant to operate even when the nearby Arkansas River is flooded, we updated controls at the plant’s effluent pump station so water can be pumped out of the plant under wet or dry conditions.
The team also renovated the anaerobic digestion and biogas system, replacing digester covers, system piping, mixers and controls as well as installing a new code-compliant gas flare to support stabilization of the biosolids into a Class B product that is used at a nearby agricultural site.
The project development scope helped the city understand the magnitude of additional improvements needed in the near future to address future water quality requirements as environmental protection drivers evolve. The team continues to work with the city to consider funding opportunities and project phasing strategies so staff can maintain compliance at a safe and reliable facility.