20211103-002c: 8921 US 290 Hwy West Wastewater SER #4796 Memo — original pdf

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ITEM FOR ENVIRONMENTAL COMMISSION AGENDA COMMISSION MEETING DATE: November 3, 2021 NAME & NUMBER OF PROJECT: 8921 US Hwy 290 West Wastewater Service Extension Request #4796 NAME OF APPLICANT OR ORGANIZATION: Joe Longaro, P.E. LJA Engineering, Inc. LOCATION: 8921 US 290 Hwy West, Austin, Texas 78737 COUNCIL DISTRICT: Austin 2-Mile Extraterritorial Jurisdiction PROJECT FILING DATE: May 18, 2020 WPD/ENVIRONMENTAL STAFF: Kaela Champlin, Environmental Program Coordinator, Watershed Protection Department (512) 974-3443, kaela.champlin@austintexas.gov WATERSHED: REQUEST: STAFF DETERMINATION: Slaughter Creek Watershed, Barton Springs Zone, Edwards Aquifer Contributing Zone, Drinking Water Protection Zone Wastewater Service Extension Staff recommends approval of the wastewater service extension 1  TO: FROM: MEMORANDUM Linda Guerrero, Chair, and Members of the Environmental Commission Kaela Champlin, Environmental Program Coordinator, Watershed Protection Department October 26, 2021 DATE: SUBJECT: 8921 US Hwy 290 West Wastewater SER #4976 Service Extension Requests (SER) located in the Drinking Water Protection Zone and outside of the City of Austin’s full purpose jurisdiction require Council approval and review by the Environmental Commission. Watershed Protection Department staff have completed the review for 8921 US Hwy 290 West wastewater SER #4976 and recommend approval of the request. Site Overview The site consists of one tract of approximately 69.12 acres, located at 8921 W US 290 Hwy. The site is located in the City of Austin’s 2-mile Extraterritorial Jurisdiction, the Slaughter Creek Watershed, the Barton Springs Zone (Contributing Zone), and the Drinking Water Protection Zone. Due to vesting rights granted per Chapter 245 of the State of Texas Local Government Code, all site development is subject to regulations in effect in 1995, which does include creek buffers, structural water quality treatment requirements, critical environmental feature (CEF) protections, and other environmental regulations, but the site is not subject to the Save Our Springs Ordinance. This property has an approved site plan for the Junction Athletic Complex, SP-2016-0607D, a proposed sports complex that has not been constructed. The applicant submitted a proposal to revise the previously approved site plan to develop a 280-unit multi-family project in the same development footprint with 140 Land Use Equivalents (LUEs). The proposed revised site plan was submitted for completeness check to the City of Austin on September 10, 2021 (SP-2016- 0607D(R1)). This property is also adjacent to the Ledgestone Multifamily wastewater SER #4622, located at 9021 W US 290 Hwy, and approved by City Council on June 11, 2020. The lines associated with the Ledgestone Multifamily SER have not been constructed. 2  Environmental Impacts The eastern portion of the site contains Devils Pen Creek and its associated critical water quality zone and water quality transition zone. There are seven wetland critical environmental features (CEFs) and one seep CEF on the property. The site does not drain to occupied salamander habitat. The previously approved site plan for the Junction Athletic Complex received three Land Use Commission variances for cut and fill exceeding four feet of depth, and construction in the water quality transition zone. Development Impacts Water: The site is in the water service area of the West Travis County Public Utility Agency (PUA). Wastewater: Due to the approved Ledgestone Multifamily SER associated with the adjacent parcel to the west of this site, there are two possible scenarios for the development of the lift station and force main for these properties. Under the first scenario, both developers will work together to build one lift station and force main to serve both properties. Under the second scenario, the developer for the SER currently under consideration (8921 US 290 W) will build a lift station and force main for this property only. When the Ledgestone Multifamily development is ready to extend service to their tract, they will be required to upgrade the lift station and force main or build their own lift station and parallel force main on their property (adjacent to the SER currently under consideration). Due to cost and limited allowable space within the ROW, the first scenario is the most likely; however, city staff cannot guarantee that the second scenario would not occur if both parties cannot come to an agreement on the first scenario. The information below describes the construction necessary for the gravity wastewater main for both the previously approved SER and the SER currently under consideration. • Approximately 1,800 feet of 15-inch gravity wastewater main (minimum 0.5% slope) from the existing 15-inch gravity wastewater main along Williamson Creek and extend west to the existing 12-inch gravity wastewater main located west of Covered Bridge Drive, as approximately shown on the attached map. The proposed 15-inch gravity wastewater main shall replace the existing 12-inch gravity wastewater main along its path. Applicant shall reconnect all existing wastewater services from the existing 12-inch gravity wastewater main to the proposed 15-inch gravity wastewater main. • Approximately 2,250 feet of 12-inch gravity wastewater main (minimum 1.0% slope) from the existing 8-inch gravity wastewater main located north of Towana Trail, and extend south towards Towana Trail, west along Towana Trail, and then south along Mowinkle Drive to the existing 8-inch gravity wastewater main in Mowinkle Drive, as approximately shown on the attached map. The proposed 12-inch gravity wastewater main shall replace the existing 8-inch gravity wastewater main along its path. Applicant shall reconnect all existing wastewater services from the existing 8-inch gravity wastewater main to the proposed 12-inch gravity wastewater main. 3  • Approximately 5,150 feet of appropriately sized force main from the proposed lift station and extend north through the subject tract and northeast along US 290 Hwy, and then north along S. Bend Dr. to the existing 8-inch gravity wastewater main located in Circle Drive. The portion of the proposed force main within the subject tract shall be located within an appropriately sized easement. Applicant shall transition to gravity service at the highest point that can be served by a proposed gravity wastewater main. Approximately 1,600 feet of the 1,800 feet of 15-inch gravity wastewater main is also proposed to be constructed by Granada Ridge (SP-2018-0138, SER #3299). If the applicant’s project timeline needs these wastewater improvements prior to the completion of them by others, then the design and construction of these improvements are the responsibility of the applicant. A conceptual drawing of the proposed wastewater main and lift station is provided in the attached SER application. The applicant has proposed to construct an appropriately sized public lift station within the subject tract at the approximate location shown on the attached map. The proposed lift station and site layout will be designed to facilitate future conversion to public by others, including the dedication of appropriately sized easements. The applicant shall dedicate appropriately sized wastewater easements from the proposed lift station to the western and northern property lines. The appropriately sized lift station and force main shall be sized to provide service to the subject tract only. However, the applicant is proposing to design the lift station so that access to the lift station is not obstructed and future expansions can be constructed. Construction of the wastewater main and lift station are required by LDC Chapter 25-8 to be located outside of the water quality transition zone and critical water quality zone. The layout of the proposed lift station will be reviewed when the project is submitted for site plan review and must comply with City Code. Should the applicant choose to pursue a lift station on this property that is in the critical or water quality transition zone, a variance approved by the Land Use Commission would be required. Staff would not recommend the variance, as the findings of fact required by the City’s Land Development Code would not be met. Alternative Wastewater Service: The site is allowed 25% net site area impervious cover. If service is not extended to the site and wastewater disposal is required, the applicant would likely apply for a Subsurface Area Drip Dispersal System (SADDS) issued by the Texas Commission on Environmental Quality. This would require 8.3 acres for a subsurface dispersal field, on-site storage, and on-site treatment plant, which would need to be deducted from the net site area calculations associated with impervious cover limits. Recommendation While sensitive environmental features do exist within the parcel and there is a concern that leaking pipes could cause environmental harm to the creek, WPD staff recommend approval of Service Extension Request #4796 for the following reasons: • The approved SER adjacent to the site will eventually allow for the construction of new public wastewater infrastructure and the proposed infrastructure is similar to that which has been approved previously for the adjacent parcel; 4  • the existing parcel already has an approved site plan for an athletic complex and the level of development associated with the proposed apartment buildings will be similar to the amount of development already allowed with the athletic complex due to site development regulations; and • the area that would be required for subsurface irrigation under an alternative wastewater treatment scenario would disturb over 8 acres of uplands. The attached information provides further detail on the applicant’s request. Please feel free to contact Kaela Champlin at (512) 974-3443 or kaela.champlin@austintexas.gov if you have any questions or comments about the proposed SER. cc: Brett Ueno, Austin Water Colleen Kirk, P.E., Austin Water Liz Johnston, Deputy Environmental Officer, Watershed Protection Department 5  WATER AND WASTEWATER SERVICE EXTENSION REQUEST FOR CONSIDERATION Name: 8921 Hwy 290 West Service Requested: Wastewater SER-4796 Hansen Service Request Number 853239 Date Received: 05/18/2020 Location: 8921 W US 290 HWY AUSTIN TX 78737 8921 Hwy 290 West Acres: 69.12 Land Use: MULTI FAMILY LUE: 140 Alt. Utility Service or S.E.R. Number: Water service provided by others Quad(s): WZ18 WZ19 Reclaimed Pressure Zone: N/A DDZ: NO Drainage Basin: SLAUGHTER Pressure Zone: SOUTHWEST C DWPZ: YES Flow (Estimated Peak Wet Weather): 131 GPM Cost Participation: $0.00 % Within City Limits: 0 % Within Limited Purpose: 0 Description of Improvements: Applicant shall construct approximately 1,800 feet of 15-inch gravity wastewater main (minimum 0.5% slope) from the existing 15-inch gravity wastewater main (Project No. 2015-0938; MH #124875) along Williamson Creek, and extend west to the existing 12-inch gravity wastewater main (Project No. 2001-0681; MH #124869) located west of Covered Bridge Dr, as approximately shown on the attached map. The proposed 15-inch gravity wastewater main shall replace the existing 12-inch gravity wastewater main (Project No. 2001-0681) along its path. Applicant shall reconnect all existing wastewater services from the existing 12-inch gravity wastewater main to the proposed 15-inch gravity wastewater main. Applicant shall construct approximately 2,250 feet of 12-inch gravity wastewater main (minimum 1.0% slope) from the existing 8-inch gravity wastewater main (Project No. 2004-0632; MH #200276) located north of Towana Trl, and extend south towards Towana Trl, west along Towana Trl, and then south along Mowinkle Dr to the existing 8-inch gravity wastewater main (Project No. 2009-0589; MH #240017) in Mowinkle Dr, as approximately shown on the attached map. The proposed 12-inch gravity wastewater main shall replace the existing 8-inch gravity wastewater main (Project Nos. 2009-0589 and 2004-0632) along its path. Applicant shall reconnect all existing wastewater services from the existing 8-inch gravity wastewater main to the proposed 12-inch gravity wastewater main. Applicant shall construct an appropriately sized private lift station within the subject tract at the approximate location shown on the attached map (located outside the 100-year floodplain and the Critical Water Quality Zone). The proposed lift station and site layout shall be designed to facilitate future conversion to public by others, including the dedication of appropriately sized easements. Applicant shall dedicate appropriately sized wastewater easements from the proposed lift station to the western and northern property lines. Applicant shall construct approximately 5,150 feet of appropriately sized force main from the proposed lift station and extend north through the subject tract, then northeast along US 290 Hwy, and then north along S. Bend Dr. to the existing 8-inch gravity wastewater main (Project No. 2009-0588) located in Circle Dr. as approximately shown on the attached map. The portion of the proposed force main within the subject tract shall be located within an appropriately sized easement. Applicant shall transition to gravity service at the highest point that can be served by a proposed gravity wastewater main. NOTES: 1) Wastewater flow based on engineering calculations received from David J. Hildebrandt, P.E. of LJA Engineering, Inc. on 6/24/2020. 2) The appropriately sized lift station and force main shall be sized to provide service to the subject tract only. 3) The lift station site shall be designed such that access to the lift station is not obstructed and future expansions can be constructed. 4) Approximately 1,600 feet of the 1,800 feet of 15-inch gravity wastewater main (between MH #124875 – 124870) is also proposed to be constructed by Granada Ridge (SP-2018-0138D; SER-3299). If the Applicant’s project timeline needs these wastewater improvements prior to the completion of them by others, then the design and construction of these improvements are the responsibility of the Applicant. Approval of this Service Extension Request is subject to completion and acceptance of the improvements described above and the conditions set forth below: 1) Construction of all Service Extensions is subject to all environmental and planning ordinances. 2) Service Extensions are subject to the guidelines established in the Land Development Code, Chapter 25-9, Water and Wastewater Utility Service. 3) An approved Service Extension is not a reservation of capacity in the system, but is an acknowledgment of the intent to serve. Available capacity shall be confirmed at the time a development application is submitted. 4) The level of service approved by this document does not imply commitment for land use. 5) If West Travis County PUA will provide water service, then for wastewater billing purposes, West Travis County PUA must agree to provide winter months (November through February) water readings to the City of Austin within 5 business days of the City’s request. Prior to construction plan approval, an agreement shall be executed between West Travis County PUA, the developer, and the City of Austin regarding this billing arrangement. 6) Public utility mains must meet City of Austin Design and Construction Criteria and must be approved by Austin Water Engineering Review. 7) Proposed public wastewater improvements will be dedicated to the City of Austin for ownership, operation, and maintenance. 8) Proposed public wastewater improvements must be placed in the public right-of-way or approved utility easements. Utility easements must be approved by Austin Water Engineering Review and must be in place prior to construction plan approval. 9) The approved Service Extension will automatically expire 180 days after date of approval unless a development application has been accepted by the Development Services Department. The Service Extension expires on the date the development expires, or if approved, on the date the development application approval expires. 10) Approval by the City Council will be required based on Austin City Code § 25-9-35. ABND PRIVATE LIFT STATION 1110 A22 9 9 0 W S H 7 1 A N C 1050 0 2 0 1 960 950 9 3 0 9 4 0 1 0 1 4 0 0 2 0 1 0 5 0 1 1 2 0 0 1 0 1 1 0 3 0 9 8 0 9 6 0 9 9 0 1 0 6 0 1100 WZ21 1100 1 1 1 0 0 8 9 970 1 0 1 0 1020 1 0 5 0 1 0 0 0 A21 GS RD 1 0 8 0 1 0 5 0 M AS SPRIN 1 0 0 0 1 0 4 0 0 2 0 1 1 0 7 0 1 1 0 0 1 0 9 0 1100 1 7 0 1 0 TH O 0 6 0 1 STAFF PROPOSED APPROXIMATLEY 2,250 FEET OF 1 0 9 0 12-INCH GRAVITY WASTEWATER MAIN (MINIMUM 1.0% SLOPE) STREA 0 1 0 1 M L U A 0 8 0 0 1 1 1 C SIDE D MURMURING CREEK DR WZ20 1 0 8 0 \ %\ %\ [7L \ %\ \ %\ \ %\ \ 0 2 0 1 \ \ \ \ \ \ \ \ \ \ \ 0 0 1 1 % \ % \ % 9 1 % % L T % \ \ % S 0 3 % A R H U \ \ \ % \ \ R H A %\ 9 6 0 R 0 8 9 V % % % % % 9 % % % % % % % % LE % \ %\ % % % % T D % %% 970 0 6 9 9 6 0 0 7 9 \ %\ % % % % 0 4 0 1 R NIG 8" P % %%%% % % % 1030 % % % 990 %% %% % % % C % % % % %%% V LANDMARK CONSERVANCY LS % % C % % % " P C % %% %% %% %% %% % V % V % % % " P % % " P 8 % % %%% % % % % % % 8 % % % %%% 8 % %% %% %% % %% %% % % % % % % % % B21 % %% % % % %% STAFF PROPOSED APPROXIMATELY [7L % %\% 1,800 FEET OF SUMMER SKY DR 15-INCH GRAVITY WASTEWATER MAIN (MINIMUM 0.5% SLOPE) %%%% % %% %% % 124869 % %% %% % %%%% % %% %%%%%%%%%%%%%%% R % GE D % % % %% %% % %%%% %% % % RID % 8" PVC %% D B %%% % % 950 % 0 % %%%%%% %% %%% 7 E 9 ER % %% C OV 8" PVC % %%% V % %%% 8" C %%%%% % 8" P % % % % % % %%%% % % % % % % %% % %%%% %% % % %%% %% % % % %% % % %% C % C % % %% %% % % V V C %%% 8" P 8" P 8" PVC V % % % % %% % % % % %% 8" P % % % % % % % % % % % 8" PVC % % %%% % NDERBIRD RD % % %% % % % % % %% 8" PVC C %%%%%% %% % % 124875 % 890 % % % % !% % %%% % %%% %%%% % %%% %%% 880 % % !% !% % %% % %% % %% % % % % %% %% % [7L %% %%%% %% AB % %% % % % % % %% % %% % % % % % % %% 920 % % % % % %%%% % % C % % V %%%%%%%%%%%% %% % 8" P % % % R E D L K WIN O 200276 M % C V 8" P % C V 8" P % 8" P % % B20 %%% %%% % N % % % % 8" P 6" P 240017 V % 0 94 0 3 9 0 7 9 THU % 930 % 9 2 0 % % N D %% % % % % % % % XT % % % % % % % % % % % % % % % % % % C C O % V C V % C % % % % % % %% A R O R 8 7 0 % % % % C 0 9 0 % % % % % % % % 0 % % % % 0 9 2 % % % % \ % W US 290 HWY %%%%% % % %%%% %%%% \\ RIDGEVIEW LS [7L %% %% % % \ %%%%%% %%%%%%%% 1040 1 0 7 0 \ % % % \ \ 1060 173 %% 0 0 0 % %%%% % 1 0 6 0 0 7 0 1 1060 B19 1010 990 0 3 0 1 9 7 0 %% % %%%%% % % \%\%\%\%\\ %\\ %\\\ %\\%\%\%\%\ \%\ %\%\ %\%\%\ 9 % 8 0 % % \ \ C \ V \ 4" P \ \ %\ 9 3 0 950 9 3 0 % % % !% % A20 T O C L R A L A N D W A N A T R L L L A R L N K A T D O H L E R E E N D N T L A R P E T PIT S 1090 A M C 0 1 1 1 A R T E R D R \ \ \ %\\ C % \ % V \ " P 240187 \ % \\ %%% \ \\\% % PRIVATE LIFT STATION 4 [7L \\ \ \\ % DI % \ 1 0 8 0 1080 \ " \ 6 %%%%% %% %%% \\\\ \\\\\\ %%%% % %%% % A19 %%% % 0 7 0 1 % 1 STAFF PROPOSED APPROXIMATELY 5,150 FEET OF APPROPRIATELY SIZED FORCE MAIN 990 1 0 1 0 950 A18 STAFF PROPOSED APPROPRIATELY SIZED LIFT STATION 930 920 0 1 9 0 4 9 1 0 1 0 1 0 2 0 980 B E L L A VIS B17 0 5 9 T A T R L B18 % 1 5 P V 9 3 0 " \ \ \ \ . % 9 %\%\ % % % 0 1 9 %%% % % % % %%% \%%%\ %% % %%% % \ 6 % 0 \ %\ 9 4 0 %\ %% 12" PVC %%%% % % %%% % %% \ %% \ %\ 920 %%%%% %%% PRIVATE LIFT STATION % [7L %%%% %% %% % % VIA RICCODR % %%% %%% % 0 7 %% %% 960 %%% 9 % % % % !% !% N % % 9 8 0 %% R N L %%% % %%% % Y D % %% % % %% %%% % O %%%% % %% % S T %%% % D T % % A R A E %% N D %%% %%% %% % B W % %% % D Subject Tract E BIO % % % % % % % % % % % % % G R A 8 8 0 C T T E Y ! ! R B D A ! ! ! ! ! % 100-yr FEMA Floodplain Full-Purpose City Limit 2-Mile ETJ Limited-Purpose City Limit 0 1,000 2,000 4,000 6,000 Feet W.W. S.E.R. Name: 8921 W. Hwy 290 West W.W. S.E.R. Number: 4796 Utility Development Services Plotted 7/27/2021 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 and represents only the approximate relative location of the property boundaries. 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. C I R C L E D R 1 0 1 0 2 0 0 0 "J 9 6 0 0 6 9 1 0 3 0 9 9 0 WZ19 1 0 7 0 1 0 6 0 1060 0 5 0 1 R E E T N O T S E G D E L 1 0 4 0 0 2 0 1 WZ18 1 0 4 0 1 0 4 0 970 0 3 0 1 1 0 3 0 1050 SANDSTONE ST 1 0 2 0 9 8 0 970 Y O U N G L N . DRAFT