07 SPC-2025-0091A - AW - Walnut Creek WWTP Expansion to 100 MGD - Overall SP A; District 1 - Staff Report

Zoning and Platting Commission – June 17, 2025

07 SPC-2025-0091A - AW - Walnut Creek WWTP Expansion to 100 MGD - Overall SP A; District 1 - Staff Report — original pdf

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ZONING AND PLATTING COMMISSION CONDITIONAL USE SITE PLAN REVIEW SHEET CASE NUMBER: SPC-2025-0091A PC COMMISSION DATE: June 17, 2025 PROJECT NAME: AW - Walnut Creek WWTP Expansion to 100 MGD - Overall SP A ADDRESS: 7113 FM 969, AUSTIN, TEXAS 78724 DISTRICT: District 1 NEIGHBORHOOD PLAN: NA WATERSHED: Walnut Creek (Suburban Watershed) AREA: 303.87 acres APPLICANT: Erik Kunkel, P.E. City of Austin, Capital Delivery Services 6800 Burleson Rd, Bldg 312, Ste 200 Austin, TX 78744 AGENT: Sharon Hamilton, P.E. Consultant City Permit Coordinator Capital Delivery Services CASE MANAGER: Meg Greenfield, (512) 978-4663, meg.greenfield@austintexas.gov EXISTING ZONING: P (Public) PROPOSED USE: The proposed use is a Major Utility Facility in Public zoning. The Walnut Creek Wastewater Treatment Plant is one of two major wastewater treatment plants that provide service to COA customers. The plant was built in different stages, and has been operational since 1977, with a major capacity expansion in 2002 to its current average daily flow capacity of 75 MGD. The current improvements generally consist of the rehabilitation of the existing 75 MGD treatment trains; implementing a 25 MGD plant expansion; and implementing a 100 MGD Wet Weather Treatment unit. With the construction of the current expansion project, the plant will have an overall capacity of 100 MGD. REQUEST: This site is zoned P (Public) and is greater than one acre in size; therefore, a Conditional Use Permit may be required, according to the Land Development Code (Section 25- 2-625). Please note this is a Land Use Element site plan and approval of this site plan does not authorize any construction. Five subsequent construction element site plans will be filed. The purpose of this site plan is to only attend Land Use Commission once instead of 07 SPC-2025-0091A - AW - Walnut Creek WWTP Expansion to 100 MGD - Overall SP A; District 11 of 17having to attend for each site plan. This is a large project, and construction will span many years, which is why it has been broken up into multiple site plans. The construction element site plans are divided into packages A, B, C, D & E for ease of design, review, and construction. These packages are separated geographically and are identified with different colors in the plans. SUMMARY STAFF RECOMMENDATION: Staff recommends approval of this site plan. LEGAL DESCRIPTION: ABS 4 SUR 19 BURLESON J ACR 303.615 EXISTING IMPERVIOUS COVER: 4% PROPOSED IMPERVIOUS COVER: 7.5% SUMMARY COMMENTS ON SITE PLAN: This site plan is still in review. It has just completed its formal review cycle. The comment report is attached. Because this is a land use site plan comments are minimal. The site development permit will not be issued until all reviews are approved. ZONING OVERLAYS: Airport Overlay: CONTROLLED COMPATIBLE LAND USE AREA ADU Approximate Area Reduced Parking Hazardous Pipelines Overlay: EQUILON Wildland Urban Interface: Proximity Class - Within 150 feet of a wildland area NEIGHBORHOOD ORGANIZATION: Austin Independent School District Austin Neighborhoods Council Del Valle Community Coalition Dog’s Head Neighborhood Association East MLK Combined Neighborhood Plan Contact Team Friends of Austin Neighborhoods Friends of Northeast Austin Homeless Neighborhood Association Overton Family Committee 07 SPC-2025-0091A - AW - Walnut Creek WWTP Expansion to 100 MGD - Overall SP A; District 12 of 17 AECOM 13640 Briarwick Drive Suite 200 Austin, TX 78729 www.aecom.com 512.454.4797 512.454.8807 tel fax April 18, 2025 City of Austin Public Projects Review Team 6310 Wilhelmina Delco Dr, Austin, TX 78752 RE: Land Use Site Plan Dear Members of Review Team, On behalf of the City of Austin and the Austin Water Utility, AECOM is pleased to submit this update to the completeness check for the Land Use Site Plan application for the Walnut Creek Wastewater Treatment Plant 100 MGD Expansion Project. This Summary Letter and the attached information form the basis of the formal land use site plan submittal. The following updated documents are enclosed for your review. Internal Plant Drainage Report (by CAS) 1. Engineer’s Summary Letter 2. Updated Plan Set 3. Plan set from 1st PPR review with comment responses embedded 4. 5. Hydrologic and Hydraulic Technical Memorandum (by CRESPO) 6. Environmental Resource Inventory (ERI) Report 7. Functional Assessment of Floodplain Health 8. TIA Determination Worksheet 9. City Arborist Review Addendum 10. Project Review Form (Ch 245) 11. Resolution 20250327-062 Site Information • Project Name: Walnut Creek Wastewater Treatment Plant 100 MGD Expansion • Project Address: 7113 FM 969, Austin, TX 78724 • Property Owner: City of Austin • Property ID:783937 • Lot Size: 303.6150 acre • Legal Description: ABS 4 SUR 19 BURLESON J ACR 303.615 • Project Type: Public Utility/ Infrastructure • Zoning: Public (P) • Type of Watershed: Walnut Creek (classified as Suburban) • Type of Development: Commercial • Acreage to be Developed:10.11acres (Proposed new) Project Description The Walnut Creek Wastewater Treatment Plant is one of two major wastewater treatment plants that provide service to COA customers. The plant was built in different stages, and has been operational since 1977, with a major capacity expansion in 2002 to its current average daily flow capacity of 75 MGD. The current improvements generally consist of the rehabilitation of the existing 75 MGD treatment trains; implementing a 25 MGD plant expansion; and implementing a 100 MGD Wet Weather Treatment unit. With the construction of the current expansion project, the plant will have an overall capacity of 100 MGD. 07 SPC-2025-0091A - AW - Walnut Creek WWTP Expansion to 100 MGD - Overall SP A; District 13 of 17 AECOM 13640 Briarwick Drive Suite 200 Austin, TX 78729 www.aecom.com 512.454.4797 512.454.8807 tel fax The Walnut Creek Wastewater Treatment plant project is divided into package A, B, C, D & E for ease of design, review, and construction. These packages are also separated geographically and are identified with different colors in Drawing NO. C00G034A. General Notes for Reviewers 1. No construction is proposed under this land use site plan. Additional construction element site plans designated as Package A, B, C, D, & E are forthcoming 2. The broad scope under each engineering package, along with design and permitting status to date is as follows: PACKAGE Scope A B C Flood wall around the plant, inside plant drainage which includes north detention pond, north storm water pump station, south water quality pond and detention basin. This package was submitted to DSD for interim review at both 30% and 60% stage. Existing 75 MGD Plant Rehabilitation which includes primary treatment complex sludge pump stations ( PTC1 & PTC2),aeration basins, 75-MDG Bio-P tanks, Electrical building, settled wastewater splitter box, substation 1A, Chlorine Contact Basin, 30 MGD filters, 75 MGD RAS/WAS PS improvement, Sludge Thickeners, NPW/Water Reuse, Hypochlorite Disinfection facilities, Odor Control Improvements, 75-MGD Parshall flume, UV disinfection basin, Final Clarifiers, site civil- piping electrical and civil. Package C consists of the Proposed Plant Area improvements which includes Primary Clarifiers and associated electrical building, Primary Sludge Pump Station, Fermenters, Aeration Basins and associated electrical building, Final Clarifiers, RAS/WAS Pump Stations, 25 MGD Blower System and associated electrical building, Filters and associated electrical building, UV Disinfection, Parshall Flume, and Post Aeration with associated electrical building, Odor Control System, Substation 4 and Junction Box #1 Permitting Status Submitted to DSD for early design review at 30% and mid design review at 60% design Submitted to DSD for early design review at 30% design Submitted to DSD for mid design review at 60% design Design Status 90% Package submitted to Austin Water on 12/23/2024 30% Package submitted to Austin Water on 04/17/2024 60% Package submitted to Austin Water on 06/11/2024 07 SPC-2025-0091A - AW - Walnut Creek WWTP Expansion to 100 MGD - Overall SP A; District 14 of 17 AECOM 13640 Briarwick Drive Suite 200 Austin, TX 78729 www.aecom.com 512.454.4797 512.454.8807 tel fax D E Wet Weather Plant Design-Transfer Pump Station, Electric Building, wet weather treatment units, wet weather blowers, chemical building and site piping, electrical I/C and civil. Outfall Pipeline and discharge structure at Colorado River. Submitted to DSD for mid design review at 60% design Submitted to DSD for early design review at 30% design 60% Package submitted to Austin Water on 07/09/2024 30% Package submitted to Austin Water on 07/29/2024 3. An ordinance associated with this land use site plan for Walnut Creek Wastewater Treatment Plant, granting DSD reviewers authority to grant variances to specific provisions of city code is underway. The resolution from the Council on 3-27-2025 is included for reference. City of Austin Permitting Topics Existing and Proposed Drainage The drainage system, water quality and detention will be addressed in Package A construction site plan, but information is provided with this submittal as a courtesy. Existing drainage for the plant discharges in Walnut Creek and Tributary 1. Drainage Areas contributing to Walnut Creek include a portion of the Existing Plant Area (Package B), the Wet Weather Plant Area (Package D), and the Proposed Plant Area (Package C). A portion of the Existing Plant Area (Package B) discharges to Walnut Creek Trib 1. Record drawings for the existing Amenity Pond, located outside the proposed floodwall, at the plant entrance north of the administrative building, were not available. Available information indicated that this pond does have an outfall to Walnut Creek. No formal water quality treatment contributing to Tributary 1 was found in the plant record drawings. The existing Amenity Pond does appear to function as a wet pond. The plant does not participate in the Regional Stormwater Management Program (RSMP). The proposed plant drainage and water quality infrastructure consists of North detention pond with associated storm water pump station, south water quality pond and detention basin. The storm conveyance system consists of four internal storm drain systems summarized in the following table: Drainage System Area Captured Discharge point (inside Plant) Included in Package/ Constructed with Package East Storm Drain System East side of the plant South detention and water quality feature West Storm Drain System West side of the plant South detention and water quality feature North Storm Drain System North of the Plant North Detention Basin A A A 07 SPC-2025-0091A - AW - Walnut Creek WWTP Expansion to 100 MGD - Overall SP A; District 15 of 17 AECOM 13640 Briarwick Drive Suite 200 Austin, TX 78729 www.aecom.com 512.454.4797 512.454.8807 tel fax Central Strom Drain and some of package A South detention and water quality feature C With the proposed infrastructure, the impervious cover in the contributing drainage area has increased. For this reason, water quality treatment is required before discharging into Walnut Creek and Trib 1. For the North Detention Pond, due to constraints within the Plant the impervious cover changes are not able to be treated for water quality in accordance with COA criteria. An alternative equivalent area of impervious cover with the East Storm drain system is proposed for treatment. The storm discharge into the Walnut Creek from east, west and central storm systems are diverted to South detention and water quality pond for water quality treatment and detention. Floodplain Modification Floodplain impacts, modification and/or mitigation will be addressed in construction site plans for the individual packages, but information is provided with this submittal as a courtesy. The project site is located within the Walnut Creek and the Colorado river floodplain. The City of Austin requires the delineation of the 100-yr flood plain based on fully developed conditions to determine the critical water quality and water quality transition zones. A fully developed 100-yr flood plain boundary was delineated for the Walnut Creek and it was determined that the site lies inside the 100-year fully developed floodplain. A feasibility study was conducted to evaluate the flood protection measures for the entire boundary of the WWWTP facility, and it was determined that a floodwall would be necessary to prevent the plant from flooding and to provide the freeboard required by FEMA. Hydraulic and hydrologic modelling (for pre and post construction conditions) was conducted to study the impact of construction of floodwall on the existing FEMA floodplain. The construction of the floodwall is shown to have potential impact on the existing floodplain. The findings of the study were shared with the COA watershed protection department for their review and comments were received. This coordination is an ongoing effort following which a CLOMR will likely be filed with FEMA. Critical Water Quality Zone (CWQZ) Critical Water Quality Zone buffer averaging is proposed and will be addressed in construction site plans for the individual packages, but information is provided with this submittal as a courtesy. The COA LDC, Section 25-8-92, establishes a protective buffer around certain streams. This is referred to as the Critical Water Quality Zone (CWQZ). Development within the CWQZ is prohibited except as provided for under LDC Section 25-8-261 (Critical Water Quality Zone Development). The CWQZ is the primary stream buffer established by Section 25-8-92 of the LDC. The Limits of Construction for Walnut Creek WWTP expansion project is located within the COA’s CWQZ of Walnut Creek and the Colorado River. A design team is currently working on a variance request to allow construction within CWQZ of Walnut Creek and Tributary 1. To minimize impact, stringent erosion control measures, stormwater management plans, and other protective strategies will be implemented. A design team is currently working on a variance request to section 25-8-261 of LDC to allow construction within CWQZ. Erosion Hazard Zone (EHZ) Erosion Hazard Zone delineation, impacts, and/or mitigation will be addressed in construction site plans for the individual packages, but information is provided with this submittal as a courtesy. COA LDC §25-7-2 defines the EHZ as an area where future stream channel erosion is predicted to result in damage to or loss of property, buildings, infrastructure, utilities, or other valued resources. As part of the latest amendments to the COA Land Development Code, consultants are required to perform an EZH analysis, to be submitted along with the development application for any project within 200 feet of the high mark of Colorado River. Erosion Hazard analysis was performed in accordance with Appendix E of DCM, for section of the Colorado River where effluent outfall structure is planned. Trees, Tree Surveys and Tree Protection 07 SPC-2025-0091A - AW - Walnut Creek WWTP Expansion to 100 MGD - Overall SP A; District 16 of 17 AECOM 13640 Briarwick Drive Suite 200 Austin, TX 78729 www.aecom.com 512.454.4797 512.454.8807 tel fax Tree Preservation, Removal and/or mitigation will be addressed in construction site plans for the individual packages where the trees are located, but information is provided with this submittal as a courtesy. As per LDC 25-8-602, trees with a diameter of 19” or larger are defined as Protected trees, and those with a diameter of 24” or larger are considered Heritage trees (Texas Ash, Texas Madrone, Bald Cypress, Bigtooth Maple, Cedar or American Elm, Pecan, Arizona Walnut, Eastern Black Walnut, or any Oak species). The tree survey was conducted in early 2023. Trees within the limits of disturbance have been identified. All trees, except those on Siphon (part of Package B), will be removed or protected as part of Package A. Tree mitigation will be provided in accordance with the rates prescribed by Chapter 25-8, Subchapter B, Article 1, Division 2 of the City of Austin Land Development Code and Section 3 of the City of Austin Environmental Criteria Manual. The tree survey data and mitigation table will be included with the individual design packages. A design team is currently working on a variance to section 25-8-642 to allow heritage tree discussions regarding preservation, removal or transplant to be made at the administrative level. Erosion and Sedimentation Controls Erosion and Sedimentation controls will be installed and maintained throughout construction of all phases of the Project. Portions of the site impacted by construction will be revegetated, restored, and cleaned up per requirements of the City of Austin Land Development Code. Silt fence, mulch socks, and rock berms are intended to serve as construction phase controls during the construction of the pump station. Erosion Control and Stabilization Practices will include the following items in the construction site plan packages: • Silt fence with J-hooks • Sedimentation/filtration water quality ponds • Stormwater Detention Ponds • Tree protection • Rock berm Critical Environmental Feature (CEF) CEF impacts and/or mitigation will be addressed in construction site plans for the individual packages, but information is provided with this submittal as a courtesy. CEFs are defined in the COA ECM §1.10.3 as features that are of critical importance to the protection of environmental resources. COA LDC §25-8-281 establishes buffer zones around these CEFs. The standard width of the buffer zone for a CEF is 150 feet from the edge of the CEF. Construction is regulated within the buffer zone. There are a total of 4 Critical Environmental Feature(s) (CEFs) on or within 150 feet of the project site (Refer to the provided ERI Report). The wetlands identified within the existing and proposed treatment plants are minimal and generally associated with drainage areas and the old lagoon. The new treatment facilities are needed in specific locations due to hydraulics (which will remove the wetlands and their buffers). A design team is currently working on a variance to section 25-8-281 of LDC to allow construction within CEF buffer. Cut and Fill Exceeding 4ft Cut and Fill will be addressed in construction site plans for the individual packages, but information is provided with this submittal as a courtesy. The City of Austin's Land Development Code (LDC), Sections 25-8-341 and 25-8-342 regulate cut and fill activities to preserve the natural character of the land and protect environmental features. Cut up to 15 feet and fill up to 25feet is anticipated for some areas where proposed infrastructure is planned for the project. The proposed cut and fill are critical as per drainage, hydraulic and geotechnical recommendations. A design team is currently working on a variance to section 25-8-341 and 342 of LDC to waive cut/fill requirements for the project. 07 SPC-2025-0091A - AW - Walnut Creek WWTP Expansion to 100 MGD - Overall SP A; District 17 of 17 AECOM 13640 Briarwick Drive Suite 200 Austin, TX 78729 www.aecom.com 512.454.4797 512.454.8807 tel fax Please advise our office if you should need any additional information for this Land Use Site Plan. We are eager to assist in the approval process. Sincerely, AECOM Technical Services, Inc. Amol Sawhney, P.E. 07 SPC-2025-0091A - AW - Walnut Creek WWTP Expansion to 100 MGD - Overall SP A; District 18 of 17 Property Profile Legend Property Jurisdiction FULL PURPOSE EXTRATERRITORIAL JURISDICTION Jurisdictions Fill Jurisdiction FULL PURPOSE EXTRATERRITORIAL JURISDICTION Zoning 1 Zoning CS DR GO GR IP LI LO LR MF MH P PUD RR SF W/LO Zoning Text Notes 0 6/12/2025 1 2 mi This product is for informational purposes and may not have been prepared for or be suitable for legal, engineering, or surveying purposes. It does not represent an on-the-ground survey. This product has been produced by the City of Austin for the sole purpose of geographic reference. No warranty is made by the City of Austin regarding specific accuracy or completeness. 07 SPC-2025-0091A - AW - Walnut Creek WWTP Expansion to 100 MGD - Overall SP A; District 19 of 17This Master Comment Report includes all staff comments received to date about your most recent site plan submittal. The comments may include requirements, recommendations, or information. The requirements in this report must be addressed by an updated site plan submittal. Case Number: SPC-2025-0091A Revision #: 00 Case Manager: Meg Greenfield Phone #: Update: U0 Email: meg.greenfield@austintexas.gov Project Name: AW - Walnut Creek WWTP Expansion to 100 MGD - Overall SP A Location: 7113 FM 969 RD Submittal Date: May 1, 2025 Report Due Date: May 30, 2025 Final Report Date: June 10, 2025 11 DAYS HAVE BEEN ADDED TO THE UPDATE DEADLINE Update Deadline (Expiration Date): May 12, 2026 Final Update Deadline [LDC § 25-5-113]:  Failure to submit a final update by the deadline will result in the automatic denial of the application, unless: (1) The site plan application has been approved; or (2) A request for an extension has been granted. [LDC § 25-1-82(F)]  If the deadline falls on a weekend or City of Austin holiday, the next City of Austin workday will be the deadline.  The applicant or their agent is responsible for updating this site plan application and clearing all comments. TO RESUBMIT:  Upload updated documents into the Bluebeam project previously provided. o Add documents to the folder “SITE” > “4 – SP Formal Review” > “U#.” If there is not a folder for the subsequent cycle, please create one for the next cycle number. o Include a full set of plans for each rejected discipline and responses to all comments. o Please do not upload outdated or unnecessary/repetitive documents to the new folder. Only upload UPDATED plans, responses to the last comment report, or documents asked for by reviewers.  Inform Puprintake@austintexas.gov and Meg Greenfield once the documents have been uploaded. Site Plan Approval:  The site plan will be approved when all requirements from each review discipline have been addressed. 07 SPC-2025-0091A - AW - Walnut Creek WWTP Expansion to 100 MGD - Overall SP A; District 110 of 17REVIEWERS: Planner 1 : Katie Luna Site Plan : Meg Greenfield Fire For Site Plan : Anne Bourland Electric Review – Tiezheng Zhao (512) 972-8482 - tiezheng.zhao@austinenergy.com Approved. Addressing Review – Kelly Delisio - kelly.delisio@austintexas.gov AD 1 Information U0 Address for this site plan 7113 FM 969 Rd AD 2 Information U0 Building numbers will need to be identified along with anything needing a permit and or electric meter, prior to Building Plan Review. Schedule a meeting to go over Addressing for this project. https://www.austintexas.gov/department/address-management-services Fire For Site Plan Review – Anne Bourland (512) 974-2115 - anne.bourland@austintexas.gov FR 1 – Current Status: Pending  U0: The project status is “Informal Update” pending feedback from the AFD HazMat group. Flood Plain Review – Zach Kretsch (512) 552-5174 - zach.kretsch@austintexas.gov General notes: This application is for a land use site plan submittal. There are no formal comments. The floodplain regulations and changes will be reviewed with package A site plan. PARD / Planning & Design Review – Kathleen Stanford (512) 974-9717 - kathleen.stanford@austintexas.gov 07 SPC-2025-0091A - AW - Walnut Creek WWTP Expansion to 100 MGD - Overall SP A; District 111 of 17PR1 – Current Status: FYI.  No further comments from PARD Planning & Design Review. However, if there are any impacts to parkland, please contact the PARD Chapter 26 team Gregory.Montes@austintexas.gov and Barry.Simons@austintexas.gov. Site Plan Review – Meg Greenfield meg.greenfield@austintexas.gov This site is zoned P (Public) and is greater than one acre in size; therefore, a Conditional Use SP1 Permit is required, according to the Land Development Code {Section 25-2-625}. Once all comments have been cleared, please contact this reviewer to schedule on the LUC agenda. An additional fee is required for the hearing notice and must be paid prior to the mailing date. As the site is not located within a Neighborhood Plan Area or other similar designation, the CUP will be considered by the Zoning and Platting Commission (ZAP). SP2 When all comments are cleared, collect signatures/authorizations from reviewers external to the City of Austin, if required. Then coordinate with the Case Manager to circulate the final plan set for City of Austin required signatures. Please allow up to 5 business days for signatures to be completed. NOTE: Any changes to the plan set following the final submittal will require the Case Manager to restart the process of collecting signatures. SP3 please add approval signature line on the coversheet for DSD. SP4 add zoning (P) and land use (major utility facilities) to site data table. Traffic Control Review – Trip Driscoll trip.driscoll@austintexas.gov This plan set has been marked "No Review Required" as the work zone is located outside of COA ROW Jurisdiction. Wetlands Biologist Review - Kenneth Sparks Kenneth.Sparks@austintexas.gov – (512) 574-8037 Please be advised that additional comments may be generated as updated information is reviewed. If an update has been rejected, reviewers are not able to clear comments based on phone calls, emails, or meetings but must receive formal updates in order to confirm positive plan set changes. CEFs and their buffers must be shown on all site plan sheets. FYI – Any Critical Environmental Features (CEFs) will need to be protected or mitigation will be required for any disturbance within the CEFs and their associated setbacks. Reference: LDC 25-8-281, LDC 25-8-282, ECM 1.10.4 07 SPC-2025-0091A - AW - Walnut Creek WWTP Expansion to 100 MGD - Overall SP A; District 112 of 17AW Pipeline Engineering – Jaron Hogenson (512) 972-0235 - jaron.hogenson2@austintexas.gov No AWPE Comments on an A plan – comments will be provided with B plan ERM Review - Kenneth Sparks Kenneth.Sparks@austintexas.gov – (512) 574-8037 Please be advised that additional comments may be generated as updated information is reviewed. If an update has been rejected, reviewers are not able to clear comments based on phone calls, emails, or meetings but must receive formal updates in order to confirm positive plan set changes. FYI – The proposed floodplain modification will be allowed under health and safety exemption and will need to comply with ECM 1.7.3(A). END OF MASTER COMMENT REPORT Comment Resolution Process: You can submit a Comment Resolution Request if: 1. You have identified two or more comments in your Master Comment Report that conflict with each other; and 2. You do not believe that the comments can be satisfied. Comment Resolution Requests can only be submitted and resolved between review cycles. They cannot be submitted while the site plan is in review. Use the Comment Resolution Request Web Form to submit your request. Questions or Concerns? Contact Us: If you have any questions or concerns or if you require more information about this report, please do not hesitate to contact your Case Manager at the email address listed at the top of this report or by writing to the City of Austin, Development Services Department, P.O. Box 1088, Austin, Texas 78767. 07 SPC-2025-0091A - AW - Walnut Creek WWTP Expansion to 100 MGD - Overall SP A; District 113 of 17 L:\DCS\PROJECTS\WTR\60682716_WALNUT_FINAL_DESIGN\900_CAD_GIS\910_CAD\A-FLOOD WALL LAND USE SITE PLAN PERMIT A\A00G030A.DWG BY: GADHIAT DATE: 3/6/2025 9:46 AM REV DATE DESCRIPTION APPROVED FOR PERMIT NOT FOR CONSTRUCTION WALNUT CREEK WASTEWATER TREATMENT PLANT EXPANSION TO 100 MGD LAND USE SITE PLAN PROPERTY BOUNDARY AECOM TECHNICAL SERVICES INC. 13640 BRIARWICK DRIVE SUITE 200 AUSTIN, TEXAS 78729 WWW.AECOM.COM TBPE REG. NO. F-3580 VERIFY SCALES BAR IS ONE INCH ON ORIGINAL DRAWING DESIGNED: XH DRAWN: AW CHECKED: ICC 0 1" APPROVED: SGE IF THIS BAR DOES NOT MEASURE ONE INCH, DWG IS NOT TO SCALE SCALE: NTS DATE: MARCH 2025 PROJECT No. 60682716 Drawing No. A00G030A SHEET No. OF 07 SPC-2025-0091A - AW - Walnut Creek WWTP Expansion to 100 MGD - Overall SP A; District 114 of 17X X X X X X X X X X X ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ EXISTING AMENITY POND ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ X ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ F H ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ X X X X X X X X X X L:\DCS\PROJECTS\WTR\60682716_WALNUT_FINAL_DESIGN\900_CAD_GIS\910_CAD\A-FLOOD WALL LAND USE SITE PLAN PERMIT A\A00G031A.DWG BY: GADHIAT DATE: 3/6/2025 12:38 PM REV DATE DESCRIPTION APPROVED FOR PERMIT NOT FOR CONSTRUCTION WALNUT CREEK WASTEWATER TREATMENT PLANT EXPANSION TO 100 MGD LAND USE SITE PLAN EXISTING CONDITIONS AND DEMOLITION PLAN AECOM TECHNICAL SERVICES INC. 13640 BRIARWICK DRIVE SUITE 200 AUSTIN, TEXAS 78729 WWW.AECOM.COM TBPE REG. NO. F-3580 VERIFY SCALES BAR IS ONE INCH ON ORIGINAL DRAWING DESIGNED: AS DRAWN: AW CHECKED: ICC 0 1" APPROVED: JNB PROJECT No. 60682716 Drawing No. A00G031A IF THIS BAR DOES NOT MEASURE ONE INCH, DWG IS NOT TO SCALE SCALE: AS NOTED SHEET No. DATE: MARCH 2025 OF 07 SPC-2025-0091A - AW - Walnut Creek WWTP Expansion to 100 MGD - Overall SP A; District 115 of 17C E F B B F E C EFB C EFB C ◊ B F E C C EFB B F E C X X X X X X X X X X X X X X X ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ EXISTING AMENITY POND ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ C E F B C E F B CEFB X 8 0 5 5 8 5 . 9 5 7 T . O . G A S L I N E T . O . G A S L I N E E L 4 N 1 E 3 9 . 8 4 . 1 0 0 1 3 9 7 4 2 3 8 5 . 9 5 7 3 2 4 8 9 6 1 8 . 5 7 . 3 5 0 0 1 E L 4 N 1 E 3 7 " P I P E 1 0 0 . 3 4 1 E L 4 6 . 2 8 8 5 7 1 . 6 0 9 3 2 4 1 " P I P E 0 . 3 4 3 4 . 3 8 8 6 . 3 9 3 2 6 0 T . O . 9 0 N 1 E 3 0 T . O . 9 E L 4 5 7 0 0 N 1 4 1 E 3 ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ F H CEFB CEFB ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ B F E C B F E C CEFB ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ ◊ B F E C C E F B C E F B B F E C CEFB C E F B B F C E B F E C B F E C C E F B B F E C C E F B E F B C X X X X X X L:\DCS\PROJECTS\WTR\60682716_WALNUT_FINAL_DESIGN\900_CAD_GIS\910_CAD\A-FLOOD WALL LAND USE SITE PLAN PERMIT A\A00G032A.DWG BY: GADHIAT DATE: 4/14/2025 3:29 PM REV DATE DESCRIPTION APPROVED FOR PERMIT NOT FOR CONSTRUCTION WALNUT CREEK WASTEWATER TREATMENT PLANT EXPANSION TO 100 MGD LAND USE SITE PLAN SITE PLAN AECOM TECHNICAL SERVICES INC. 13640 BRIARWICK DRIVE SUITE 200 AUSTIN, TEXAS 78729 WWW.AECOM.COM TBPE REG. NO. F-3580 VERIFY SCALES BAR IS ONE INCH ON ORIGINAL DRAWING DESIGNED: AS DRAWN: AW CHECKED: ICC 0 1" APPROVED: JNB PROJECT No. 60682716 Drawing No. A00G032A IF THIS BAR DOES NOT MEASURE ONE INCH, DWG IS NOT TO SCALE SCALE: AS NOTED SHEET No. DATE: APRIL 2025 OF 07 SPC-2025-0091A - AW - Walnut Creek WWTP Expansion to 100 MGD - Overall SP A; District 116 of 17F H F H X X X F H F H F H F H F H X L:\DCS\PROJECTS\WTR\60682716_WALNUT_FINAL_DESIGN\900_CAD_GIS\910_CAD\A-FLOOD WALL LAND USE SITE PLAN PERMIT A\A00G034A.DWG BY: GADHIAT DATE: 4/14/2025 4:30 PM REV DATE DESCRIPTION APPROVED FOR PERMIT NOT FOR CONSTRUCTION WALNUT CREEK WASTEWATER TREATMENT PLANT EXPANSION TO 100 MGD LAND USE SITE PLAN PACKAGE AREA DESIGNATIONS AECOM TECHNICAL SERVICES INC. 13640 BRIARWICK DRIVE SUITE 200 AUSTIN, TEXAS 78729 WWW.AECOM.COM TBPE REG. NO. F-3580 VERIFY SCALES BAR IS ONE INCH ON ORIGINAL DRAWING DESIGNED: AS DRAWN: AW CHECKED: ICC 0 1" APPROVED: JNB PROJECT No. 60682716 Drawing No. A00G034A IF THIS BAR DOES NOT MEASURE ONE INCH, DWG IS NOT TO SCALE SCALE: AS NOTED SHEET No. DATE: APRIL 2025 OF 07 SPC-2025-0091A - AW - Walnut Creek WWTP Expansion to 100 MGD - Overall SP A; District 117 of 17