03-1: Walnut Centralized Facility Presentation — original pdf

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AUSTIN WATER GREATER WALNUT CENTRALIZED ODOR CONTROL FACILITY PROJECT Chapter 26 Application for AW Infrastructure within Parkland at Balcones District Park Parks Board Meeting City Hall Chambers7/28/2025 @ 6:00 PM 1 TOPICS COVERED • Overall Project Summary • Project Objective/Benefits • Site Evaluation • Parkland Impacts 2 GREATER WALNUT INTERCEPTOR AREA 3 BACKGROUND • Odor issues along Walnut Creek interceptor, including cluster of complaints in Balcones Park area • Odor control: fans to withdraw air from sewer and treatment process to control odor in exhaust air • To reduce impact, primary treatment will be low-profile biotrickling filters, which requires smallest footprint • Balcones District Park is a strategic location. Confluence of smaller collectors, beginning of large interceptor • Several locations considered for odor control facilities 4 FAN TESTING RESULTS 5 RECOMMENDED APPROACH FOR CENTRALIZED ODOR CONTROL: TWO FACILITIES 6 RECOMMENDED APPROACH FOR CENTRALIZED ODOR CONTROL: BIOTRICKLING FILTERS Typical Schematic Low Profile Biotrickling Filter 7 PROPOSED SITE LOCATION 8 BALCONES DISTRICT PARK LOCATION • Best location for odor control facility – maximizes zone of influence • Facility and Walnut Creek interceptor on same side of the creek • Outside Critical Water Quality Zone and Edwards Aquifer recharge zone • Adjacent to Mopac Expressway and commercial area • Adequate separation from structures north and south of facility • Away from hike/bike trail, screened by trees 9 OTHER SITE LOCATIONS CONSIDERED Location A • Privately owned • In Critical Water Quality Zone • Opposite side of Walnut Creek, would require above ground air duct Location B • • • Next to hike/bike trail • Greater park impact/disruption Location D • North Austin Medical Center In Balcones Park property In Critical Water Quality Zone parcel • Near interceptor but a significant distance from cluster of complaints Site has been developed by medical center • 10 SITE PHOTOS 11 ENTRANCE TO SITE – VIEW FROM MOPAC 12 PROPOSED SITE – VIEW FROM PARKING LOT 13 AIRDUCT ROUTE – WEST STARTING FROM TRAIL 14 MINIMIZING IMPACTS TO PARK • Site borders MOPAC and commercial area and is a low usage area of the park • Smallest possible site area for facility • Low profile biotrickling filters and separation from trail reduces visual impact • Outside Edwards Aquifer Recharge Zone and Critical Water Quality Zone • Not within presumed endangered species habitat. • Temporary trail reroutes provided for construction of air duct and WW line and driveway across trails. • Site runoff controls provide no net increase in runoff flow rate from the site. • Very low traffic impact – few periodic (typically weekly) operations/maintenance trips to the site. Sensitive / Confidential / Proprietary 15 CHAPTER 26 PARKS AND WILDLIFE CODE DUE DILIGENCE FOR UTILITY ASSIGNMENT • Section 26.001 • 1. 2. A department may not approve any project that requires the use of any public land designated as a park unless the department, acting through its duly authorized governing body or officer, determines that: There is no feasible and prudent alternative to the use or taking of such land – CONFIRMED The program or project includes all reasonable planning to minimize harm to the land, as a park, recreation area, scientific area, wildlife refuge, or historic site, resulting from the use or taking - CONFIRMED • Austin Water requests a recommendation to City Council for approval of 31,694 square feet for permanent use on parkland located at Balcones District Park. Mitigation amount $742,361. Sensitive / Confidential / Proprietary 16