The Harris County MUD 449 Wastewater Treatment Plant Expansion Project involved the construction of a new permanent concrete wastewater treatment plant while repurposing as much existing equipment as possible. Due to the complex site configuration, the expansion area was limited. To overcome this challenge, a common wall was constructed to increase expansion capacity on the existing site. The new basins featured two aeration basins, two final clarifiers, and two chlorine contact chambers. The new basins have a 16.5-foot-side water depth and are partially below grade to be consistent with aesthetic features of surrounding neighborhoods.
The facilities requiring expansion were also common wall construction, and the EHRA team converted the facilities into aerobic digesters and sludge thickeners. Existing clarifiers were reconfigured into sludge thickeners, and the aeration basins and digesters were transformed to become single digesters. Ultimately, the reconfiguration and expansion of the plant resulted in four aerobic digesters and two thickeners.
Additional project highlights include the tertiary filters EHRA added to address stringent discharge requirements and provisions to the effluent to allow reuse for irrigation of common areas. EHRA further incorporated a Parshall flume into the design, permitting the operator to manage one flow meter for reporting, despite running two chlorine basins. Lastly, a 500-KW emergency generator was installed to support the facility during prolonged power outages.
