In 2017, the Town completed a comprehensive Water Distribution System Assessment that included a Capital Improvements Program (CIP) that made recommendations for the replacement of and improvements to water lines, as well as other water quality improvements. One of the water quality improvement recommendations is the addition of chlorination injection equipment to the Town's water distribution system.
The Town purchases potable water from Dallas Water Utilities. Dallas Water Utilities provides disinfected water with a chlorine residual at two entry points in town, Celestial Ground Storage Tank and Surveyor Ground Storage Tank. Because the Town does not have the ability to disinfect the water once it enters the distribution system, there is no way to inject more chlorine should the residuals fall below a safe level. The addition of a chlorine injection system provides several benefits to the water system.
- Provides for operational redundancy in the event that Dallas Water Utilities cannot provide potable water at the regulatory required chlorine residual rate due to an equipment failure, main break, or other reason.
- Provides enhanced, more consistent water quality throughout the Town's water distribution system.
- Reduces the need for flushing water lines due to low chlorine residuals in the system, particularly during the summer months. This also reduces the amount of non-revenue producing water the Town uses.
- Reduces the number of customer complaints regarding water taste, color, or odor.
- Provides an increased level of operational flexibility in water distribution system management.
- Increases the life of water system infrastructure components such as pipes, valves, and meters.
Garver was qualified through a Request for Qualifications process in 2017 to perform design, project management, and construction management related services for the Town. Garver has a long history of performing water quality improvement projects for governmental agencies. They come very highly recommended by their references and staff finds them capable of performing this work.
Garver's scope of work will include design, bid and construction phase services for this project. A more detailed breakdown of their scope of services is included below:
- Data collection and review - Engineer will obtain all necessary documents including current water distribution system models, pumping records, water storage facility as-built records, water flushing records, monthly operating reports, GIS (geographical information system) maps, previous engineering reports and records and distribution system SCADA (Supervisory Control and Data Acquisition) data.
- Design and dosage requirements - Engineer will identify the most appropriate injection site locations and prepare dosing requirements based on current water quality information. Two sites will be selected. They will prepare design documents for the chlorine equipment and housing structures. They will also prepare designs for all associated electrical and instrumentation controls to fully integrate and automate the system into the Town's existing SCADA system. They will also develop the ongoing operational costs associated with the selected chlorine booster system.
- Regulatory Coordination - Engineer will submit plans and specifications to the Texas Commission of Environmental Quality (TCEQ) for approval. They will respond to comments and questions from TCEQ, and provide any necessary supplemental information for construction plan approval.
- Bid phase services - Garver will prepare and issue a biddable set of construction plans and specifications for the project. They will respond to questions, participate in the pre-bid meeting, issue addendum and evaluate bids for the recommendation of award.
- Construction phase services - Engineer will evaluate and respond to construction material submittals and shop drawings, respond to contractor RFI's, review pay applications, perform periodic site visits to evaluate contractor performance and prepare the final project punch list.
A detailed breakdown of Garver's proposal is provided below:
| Service |
Fee |
| Design Phase |
$197,060 |
| Bid Phase |
$9,048 |
| Construction Phase |
$41,996 |
| Total |
$248,104 |
Design is expected to take 5 months to complete. The total cost for these engineering services is $248,104, and it will be paid from the Water System Improvements project in the Utility Capital Improvements Program budget. The budget for this design is $350,000. |