City of Dallas


Dallas, TX



Dallas Water Utilities’ (DWU) Wastewater Treatment Facility Strategic Plan specifically includes Capital Improvement blanket line funding items every five years to address “major maintenance” projects for all of DWU’s major treatment facilities. When DWU identified major maintenance and improvements at Southside Wastewater Treatment Plant for the 2015 and 2020 planning years, the City chose to work with Gresham Smith for engineering and contract administration services. We helped identify, prioritize and build consensus for the projects at the plant that would drive the greatest value for the budget, and then successfully evaluated, prioritized, and designed projects touching most unit processes throughout the campus.

Under the 2015 major maintenance contract, Gresham Smith evaluated, design and provided construction-phase services for projects throughout the plant, including:

  • Replacement of corroded equipment and miscellaneous large valves, gates, instrumentation, equipment control panels, etc.
  • Upgrades to influent and effluent pump station variable frequency drive
  • Replacement of an old chlorine scrubber system
  • Electrical upgrades to the Administration Building air conditioning system
  • Replacement of Gravity Belt Thickener control panels and building gas monitoring system
  • Upgrades to primary and secondary clarifier drives, chlorine and sulfur dioxide safety equipment
  • Replacement of building-heat hot water loop yard piping system throughout the plant that was originally constructed out of 30-year old fiberglass pipe

Under the 2020 major maintenance contract Gresham Smith completed additional projects, including:

  • Rehab of the solids screening and thickening building for GBT rehab (6 tables)
  • Replacement of 3 drum screens, upgrades to the ventilation and custom in-ground biofilter odor control system, and various E&IC upgrades
  • Upgrades to critical pump stations throughout the plant, including the 3 MGD Lagoon B Pump Station, 6 MGD Dewatering Filtrate Pump Station, and 5 MGD Lagoon A Pump Station.
  • Cleaned all anaerobic digesters and feed wells and replaced insulation on digester steel covers

In addition to the maintenance upgrades, Gresham Smith designed stormwater improvements at the Southside Wastewater Treatment Plant. The improvements include 10 tasks related to plant-wide challenges, including drainage improvements, stormwater management through pump stations, and additional miscellaneous mechanical improvements related to process/mechanical components. The improvements are intended to alleviate localized flooding and mitigate current and future stormwater flows.

It was a great experience working with Gresham Smith on the Southside WWTP Major Maintenance project. Throughout the design process, Gresham Smith managed the project along with their subconsultants in such a manner that the project management and plant staff were continually updated and involved throughout the process. The Gresham Smith team delivered a project that was completed on time and construction bid was on budget. Leslie Castillo, P.E. Project Manager, City of Dallas