Location

  • Houston, Texas

Client

  • North Park Utility District

Status

Services Provided

Shortly after becoming the District Engineer for North Park Utility District, CobbFendley became aware of the severe degradation to the District’s Wastewater Treatment Plant. The facility operated at approximately 0.98 million gallons per day (MGD) average daily flow but is designed for 1.31 MGD average daily flow, allowing for a separation of flow between two treatment units.  Treatment Unit 2 of the plant had extensive degradation to the air headers and wall thickness due to aging materials. After further inspection of the Unit as well as receiving inspection reports regarding the degradation of the air header, CobbFendley advised the client to declare repair of the Unit as an emergency project to the TCEQ to be able to address this problem as quickly as possible.

The emergency project entailed hiring two contractors directly with approval from TCEQ to waive bidding requirements as well as approval of the design. The Mechanical Contractor fabricated and installed new skimmer arm, hot dip galvanized (HDG) weir plates for the launder trough, HDG air header, pipe supports, air drops, HDG RAS line, and black steel scum airlift and piping. The Coatings Contractor blasted and recoated the interior and exterior of the tank, repairing any holes that presented during the process. During the project, an additional digester was brought in on a temporary basis to allow for ongoing operations of the treatment facility.

CobbFendley was able to quickly design the repairs to the facility and work with the contractors and operator for a successful project. Within 6 months, the treatment unit was taken offline, cleaned, rehabilitated and brought back online. Based on inspection of the air header and piping pulled from the Unit during construction, it could be seen that catastrophic failure of the Unit was imminent if this rehabilitation project had not been completed.