Water Supply Feasibility Study. Public Works Committee Presentation March 2009

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1 Water Supply Feasibility Study Public Works Committee Presentation March 2009

2 Public Works Committee The Public Works Committee is made up of citizens with both technical and non-technical backgrounds who provide support to the Public Works Department, the Mayor, and City Council on city infrastructure and planning issues. Examples of current projects being reviewed by the Public Works Committee at the time of this printing include: Review of the city s Drainage Master Plan Riverine Flooding Issues Review of the city s Flood Abatement Program Localized Flooding Issues Analysis of the planning/engineering requirements for drilling a new city water well Review of transportation infrastructure improvements Monitoring of on-going capital improvement projects (street replacements) Review of ordinances pertaining to streets, water, and wastewater The Committee typically meets 1st & 3rd Thursday evenings at City Hall. The frequency of meeting is determined by current workload and on-site meetings are held as needed so that members may observe project related issues.

3 Public Works Committee Directive

4 Existing Conditions City of Sunset Valley Ground Water Plant serves 113 homes and City Hall. Sunset Valley has a permit from the Barton Springs Edwards Aquifer District to pump 18 million gallons annually. Sunset Valley estimated use is 17.5 million annually. With final build out of residential area at 145 homes Sunset Valley will need 25 million gallons annually. To increase permit volume Sunset Valley will be required to reduce use during drought conditions.

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6 Status of Sunset Valley Water Plant Well was drilled in diameter and 360 feet deep Well is cased 100 feet deep Plant has two 45,000 gallon steel storage tanks Tank one was erected in 1974 Tank two was erected in 1980 Fiberglass liners were installed in ,000 gallon pressure tank was installed in 1974 and refurbished in 2008 Chlorine disaffection is performed by injection from two 150 lb chlorine bottles. Emergency COA Connection upgraded in 2006.

7 Emergency Austin Connection Emergency Water Plant by-pass connection to COA water

8 Status of Sunset Valley Water Plant Con t Current water plant meets or exceeds minimum TCEQ requirements. Upgrades are needed due to age and condition.

9 History of the Project 2007 Espey Consultants contracted to perform Water Plant and Community Well Feasibility Study Phase 1 Tasks: Identify and investigate well sites Identify ground water quality and quantity Evaluate Ground Storage and Elevated Storage Options Provide Cost Estimates Research Permit requirements

10 Feasibility Report Scenarios Scenario 1 All COA Supplied Water Scenario 2 Current Water Supply Service Areas Scenario 3 All Residential Areas Supplied by Groundwater Well These scenarios are for comparison purposes only. Only the options listed in Scenario 2 are being considered for action.

11 Water Source Transfer Petition In the summer of 2007 the City Council approved Ordinance # requiring the filing of a water source transfer petition prior to the transfer to a different water source. Because of this ordinance the Council can only discuss or consider action on options that keep the current water service areas.

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13 Espey Report Scenario 2 Water service areas remain the same. Water plant will only serve Old Town, City Hall and possibly Triangle/Upland Tract. Water plant can be located at City Hall, Triangle or Upland Tract. Water Plant can be Ground Storage or Elevated Storage with or without additional fire demand storage.

14 Basic Components proposed Well Systems 400 deep 6 groundwater well with full depth casing and submersible pump Ground storage 10,000 gallons with pressure tank or Elevated Storage 250,000 gallons Distribution Pumps two 30hp centrifugal pumps Filtration and Chlorine disinfection

15 Scenario 2 Considerations Fire Protection Filtration and Disinfection Location Safety Security Aesthetics Maintenance Cost

16 Fire Protection The emergency by-pass connection to City of Austin serves a back up potable water source during drought conditions and system failures. This connection also provides a manual backup for fire flows. This inter-connection eliminates the need for fire flow storage volume on site. In the event of a long term power outage the City of Austin water supply is backed up by generators and elevated storage.

17 Filtration and Disinfection All options in the report call for filtration to remove calcium deposits from the well water. Filtration maintenance requirements need to be considered during design process. Automatic flushing is preferred over manual removal. Disinfection treatment method i Chlorine. The state requires a chlorine residual in the water system. Additional disinfection methods are available but work be redundant due to the chlorine requirement.

18 Location Three sites were considered in the report. Site 1 Uplands Tract on North Pillow Site 2- Triangle Tract on North Pillow Site 3 Existing Well site at City Hall All sites would require Sanitary Control Easements around well head. Current Water Plant location on Site 3 is partially within the Water Quality Transition Zone.

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20 Safety Emergency Power The city currently operates a backup generator to the existing water plant. This generator can be modified to serve the new facility. Backup water - COA Chlorine A containment area must be installed to control a leak or spill. Mandatory: panic hardware, vent fan and air pack Additional: automate vent fan, leak detector with alarm, auto dialer, additional third level containment.

21 Security Fencing Water plants require perimeter security fencing. Lighting elevated tank would require illumination. Alarms security alarms could be silent.

22 Aesthetics Fencing and Lighting Height Elevated tank would require a variance to Land Development Code height restrictions Elevated tank could provide an opportunity for a signature Sunset Valley sign.

23 Maintenance Elevated tanks will require contractor assistance for tank maintenance. Annual internal inspection Exterior and interior painting every 20 yrs will extend life of tank. Ground tank will require annual cleaning and inspection. Tank cleaning is currently performed by staff. Exterior and interior treatments are available to extend life of tank.

24 Cost with Fire Protection Storage

25 Cost Without Fire Protection Storage

26 Additional Cost for Sites 2 & 3 Test wells cost +/-$20k. At least one test well would be required during the preliminary design phase

27 Timeline Preliminary Design and testing 2009 Final Design 2010 Construction 2010/2011

28 Funding Considerations General Fund has $300k in FY 08/09 for Water Plant Replacement Water Rate Funded (Utility Fund) Bond Loan Grant