Specifications include, but are not limited to: The Walnut Creek Wastewater Treatment Plant (WWTP) receives wastewater flow from Austin Water's wastewater collection system. The plant was originally built in 1977. Over the years, the treatment plant has undergone numerous improvements and upgrades to modernize treatment methods as well as expand treatment capacity to 75 million gallons per day (MGD) with a 2-hour peak flow of 165 MGD. Treated plant effluent is discharged into the Colorado River. A portion of the treated effluent is used for non-potable water (NPW) on the plant site and supplies much of the City’s Reclaimed Water program. This project will expand the plant to treat and discharge an annual average daily flow of 100 MGD and a 2-hour peak flow of 300 MGD. The expansion is needed based on projected future flows of wastewater into the plant, in accordance with Texas Commission on Environmental Quality (TCEQ) regulations and the requirements of Texas Administrative Code. Additionally, the project will implement Biological Nutrient Removal (BNR) in both the existing and proposed facilities to meet more stringent effluent quality limits in the plant’s discharge permit issued by TCEQ that go into effect with the expansion. The project includes several distinct components: a new 25 MGD treatment train with BNR, upgrade of the existing treatment to BNR, new peak flow treatment, new influent siphons, new effluent pipe and outfall, and a flood wall around the site. • Two new 72” influent siphons across Walnut Creek into the plant • Upgrade of the existing 75 MGD plant process to BNR, centralized odor control for the existing plant, conversion to Ultraviolet (UV) disinfection, 30 MGD cloth disk filters, including supporting electrical and controls buildings and infrastructure, and extensive site utility relocations and new site utilities • New 25 MGD treatment train (primary clarifiers, secondary treatment, final clarifiers, cloth disk filters, UV disinfection), including BNR process and fermenter tanks with odor control, including supporting electrical and controls buildings and infrastructure, and site utilities • AquaStormTM filters for wet weather/peak flow treatment • New 120” effluent pipe and outfall to the Colorado River • New flood wall around the entire site and site drainage • Headworks Building #2 improvements • Headworks Building No. 1 improvements and rehabilitation and associated electrical upgrades • Influent Lift Station for the Johnny Morris Interceptor and associated electrical work • Subsidiary services: • Startup and Commissioning services • Subsurface Utility Engineering (SUE) and utility mapping services
