20240904-002: 1107 Castle Ridge Rd WW SER 5845 Memo — original pdf

Backup

ITEM FOR ENVIRONMENTAL COMMISSION AGENDA COMMISSION MEETING DATE: September 4, 2024 NAME & NUMBER OF PROJECT: 1107 Castle Ridge Road Wastewater Service Extension Request #5845 NAME OF APPLICANT OR ORGANIZATION: Andrew Milam, Parkside Homes LLC LOCATION: 1107 Castle Ridge Road, Austin, Texas 78746 COUNCIL DISTRICT: Austin 2-Mile Extraterritorial Jurisdiction PROJECT FILING DATE: February 5, 2024 WPD/ENVIRONMENTAL STAFF: Kaela Champlin, Environmental Program Coordinator (512) 974-3443, Kaela.Champlin@austintexas.gov WATERSHED: REQUEST: STAFF DETERMINATION: Barton Creek Watershed, Barton Springs Zone, Edwards Aquifer Contributing Zone, Drinking Water Protection Zone Wastewater Service Extension Revision Not Recommended 1  MEMORANDUM August 6, 2024 Perry Bedford, Chair, and Members of the Environmental Commission Kaela Champlin, Environmental Program Coordinator Watershed Protection Department TO: FROM: DATE: SUBJECT: 1107 Castle Ridge Road Wastewater Service Extension Request #5845 Service Extension Requests (SERs) 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. The Watershed Protection Department (WPD) staff have completed the review for 1107 Castle Ridge Road Wastewater SER #5845 and do not recommend approval of the request. Site Overview The site consists of one tract of approximately 2.85 acres, located at 1107 Castle Ridge Road. The site is in the City of Austin’s Two-Mile Extraterritorial Jurisdiction (ETJ), the Barton Creek Watershed, the Barton Springs Zone, and the Drinking Water Protection Zone. It is also within the Edwards Aquifer Contributing Zone and is subject to the Save Our Springs (SOS) Ordinance. Request Summary The applicant is proposing to subdivide the 2.85-acre lot into three single family residences for homes with driveways and a fire truck turnaround entrance. There is an existing structure on the center lot that will be replaced. The SER is requesting three Living Unit Equivalents (LUEs). A site plan has not yet been submitted to the City of Austin. Impacts from SER improvements Wastewater: The applicant is proposing to construct 760 feet of appropriately sized gravity wastewater main from the existing 8-inch gravity wastewater main located in Whitemarch Valley Walk and extend north to and through the subject tract to Castle Ridge Road as shown on the attached map. Alternative Wastewater Service: The combined average flows from all three houses are estimated to be 735 gallons per day (GPD). If service is not extended to the site and wastewater disposal is required, there are two 2 options for this amount of effluent treatment: Onsite Sewage Facility (OSSF) or land application (surface irrigation or subsurface land application). Land application would require a Texas Land Application Permit (TLAP), or a Subsurface Area Drip Dispersal System (SADDS) issued by the Texas Commission on Environmental Quality (TCEQ). The soils on the site are predominantly Brackett-Rock outcrop with a small portion of Eckrant very stony clay on the northernmost lot. The topography has an overall slope of 14.4% from Northwest to Southeast with a drop of 84 feet. Brackett-Rock outcrop soils are not ideal for OSSFs or land application because the soil type is thin and rocky and there are severe limitations for septic tank absorption fields and pond construction noted in the soil survey due to the shallow depth of bedrock. Soil could be imported at a considerable expense, but the land application system maintenance requirements would increase due to the underlying Brackett soils. Soil piping and preferential flow paths would likely form, allowing wastewater migration below the root zone. A TLAP is not appropriate for the proposed development because the flows from all three houses would be significantly less than that requiring a TCEQ permit (5,381 gallons per day). OSSFs could be developed with single family residences, but Travis County requires a lot size of at least one acre for OSSFs. Under these rules, the currently proposed site plan would need to be redesigned for only two lots. However, in this case, this would not necessarily reduce the total amount of impervious cover of the proposed development, because the applicant would likely maximize the allowable impervious cover whether there be two or three lots. Water: The applicant has not submitted a water service extension request to the City of Austin. Water service will be provided by Travis County WCID #10. ETJ Regulations During the 88th Texas Legislative Session in 2023, state lawmakers passed Senate Bill 2038 granting property owners the authority to file a petition or request an election for release from a city’s ETJ. The bill allows properties to be removed on a lot-by-lot basis, significantly hindering regional planning efforts for long-term sustainable growth. The bill negatively affects Austin’s ability to regulate environmental and water quality protection requirements. Under this new law, property owners in Austin’s ETJ may obtain services from the City and subsequently request to be removed from the ETJ. Once released, there is no longer a requirement to comply with the City’s environmental regulations in these areas. Environmental impacts The property is in the Barton Creek Watershed, the Barton Springs Zone, the Drinking Water Protection Zone, and the Edwards Aquifer Contributing Zone. The property lies within the Camelot Section 3 subdivision, which was recorded in 1969. The existing subdivision was not subject to current environmental regulations, including the Save Our Springs Ordinance (SOS) and Watershed Protection Ordinance (WPO), but a future subdivision would be subject to both SOS and the WPO. In the Barton Creek Watershed outside of the Edwards Aquifer Recharge 3 Zone, the SOS Ordinance limits the total amount of allowable watershed impervious cover to 20% of the net site area and construction on slopes greater than 15% would be limited. Based on available information, a significant portion of the site contains slopes greater than 15%. No critical environmental features were identified in the Environmental Resource Inventory (ERI) and the site is not within the critical water quality zone or water quality transition zone of Barton Creek. The site does not drain to occupied salamander habitat. WPD staff verified the findings of the ERI during a site visit on February 27th, 2024. The lots are heavily wooded based on the aerial photographs and field verification of the ERI. Vegetation identified includes Ashe Juniper, Live Oak, Texas Persimmon, Yaupon and Texas Mountain Laurel being the predominant woodland species. The ERI did not mention any endangered Golden-cheeked Warbler habitat. The Travis County Habitat Map shows the site as predominantly Unconfirmed Habitat Zone 2 with a portion of Lot 1 on the north side as Confirmed Habitat Zone 1 for Golden-cheeked Warbler Habitat. The applicant has not submitted a site plan with the City of Austin, but a land use plan was provided with the SER. If the property owner decided to petition for release from the City’s ETJ after receiving a wastewater SER for this site, they would be able to develop with fewer environmental protections in place, namely the highly protective SOS impervious cover limits and non-degradation water quality treatment standards, as well as the slope protections found within the WPO. Recommendation The Watershed Protection Department does not recommend approval of the wastewater SER #5845 for the following reasons: - The site contains steep topography with many areas of slopes greater than 15% and is therefore sensitive to impacts of development, - The original subdivision was approved prior to the adoption of the Save Our Springs Ordinance and facilitating additional density and impervious cover in this neighborhood beyond what exists currently could lead to an overall increase in non-compliance with the SOS ordinance over time, - WPD supports development that complies with the City of Austin’s environmental regulations and currently there are no assurances that the site will continue to remain within the City of Austin’s ETJ in the future. If the site were to request removal from Austin’s ETJ, it would no longer be subject to Austin’s environmental regulations, including the SOS Ordinance. The attached map provides further details 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 revision. cc: Cole Huggins, P.E., Austin Water Colleen Kirk, P.E., Supervising Engineer, Austin Water Leslie Lilly, Environmental Conservation Program Manager, Watershed Protection Department Liz Johnston, Interim Environmental Officer, Watershed Protection Department 4 8 1 0 0 8 8 J O U S T I N G P L D E R G E R I D L T S A C 9 1 0 900 890 R D E G D E L N O C L A F 8 8 0 0 3 8 7 9 0 8 0 0 7 6 0 7 5 0 7 8 0 7 4 0 7 7 0 STAFF PROPOSED APPROXIMATELY 760 FEET OF APPROPRIATELY SIZED GRAVITY WASTEWATER MAIN D24 890 Lot 2 0 1 8 Lot 1 870 Lot 3 0 4 8 !P % % 0 2 8 0 1 8 8 0 0 850 R D D A H A L A G % 8" PV % 0 1 8 0 0 8 % C WHITEMARSH VALLEY WALK %% !P C V 8" P % %%%% 8" PVC M % !P I N I K A H D % A C V % 8" PVC % % !P % 8 " P V % C % !P % !P % C V % P " 8 % 8 " P V C % % % !P % 7 7 0 860 % !P TO !P % 8 " P % V C C V 8" P % !P RREY PINES CV . 0 100 200 400 600 Feet W.W. S.E.R. Name: 1107 Castle Ridge Road W.W. S.E.R. Number: 5845 Utility Development Services Plotted 11/27/2023 R D N O Y N A C N A D N I I IN DIA N C A N Y O N C V Subject Tract 100-Year COA Floodplain Critical Water Quality Zone Full-Purpose City Limit 2-Mile ETJ 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. DRAFT