Feature Photo: A bird’s-eye look at the New Braunfels Utilities Surface Water Treatment Plant. NBU plans to double its capacity by 3rd Quarter 2023. Image: Google Earth.
Posted: 3-12-2021
by Adolfo Pesquera
New Braunfels (Comal County) — New Braunfels Utilities anticipates closing by May 1 on a $40 million loan it needs to double the capacity of its Surface Water Treatment Plant.
The Texas Water Development Board on Wednesday approved a request for the loan from the Drinking Water State Revolving Fund.
NBU’s current treatment capacity is inadequate for projected water demands, and existing infrastructure at the Surface Water Treatment Plant (SWTP) is located in the floodplain. Significant flooding from the Guadalupe River occurred at the plant in 1998 and 2002.
The city-owned utility has also identified additional areas of the existing SWTP that need improvement, such as the filter backwash system and the safety of the chlorine system.
In response to increasing demand for potable water in the City of New Braunfels, NBU secured the water rights to a firm yield supply of 16 MGD of surface water through Guadalupe River run-of-river water permits and Guadalupe-Blanco River Authority Canyon Reservoir water. This SWTP Expansion project will double the current treatment capacity of the SWTP to allow for treating these additional water rights.
Additionally, the new treatment processes and equipment will be more robust and flexible, thus allowing for improved water quality, better safety for the operators and community, and more resilience during flooding.
The treatment plant is located at 2356 Gruene Road, toward the center of NBU’s service area and approximately a quarter mile from the banks of the Guadalupe River. Proposed project improvements will occur within the existing developed facility.
Project Name: NBU Surface Water Treatment Plant Expansion
The city-owned utility proposes to expand its existing 8 million-gallons-per-day (MGD) water treatment plant to 16 MGD.
To protect the SWTP from flooding, the improvements will include constructing a berm or flood wall around the perimeter of the facility, elevating raw water pumps and electrical equipment, and a new, enclosed chlorine building elevated above the floodplain with a dry scrubber system.
Preparation of the Environmental Information Document (EID) is conducted during the planning phase of the project, after a loan commitment has been secured. Issuance of an environmental determination by TWDB staff is required prior to TWDB approval of the Engineering Feasibility Report and release of design and/or construction funds.
The scheduled closing date on the financial agreement is May 1, and the Engineering Feasibility Report (end of planning phase) is due May 7. The Austin office of Arcadis U.S. Inc. has been conducting the engineering study.
The design phase is expected to conclude June 1, 2022. Following this, construction is scheduled to begin Nov. 1, 2022 and be completed by Sept. 29, 2023.
The project budget summary designates $27,549,000 of the total for actual construction. Engineering and related services is approximately $5 million. Fiscal services has an estimated cost of just under $2 million, and there is a $5.5 million contingency fund.
The “design year” on this project is 2042, meaning the design goal is to meet the needs of the service area for the next 20 years. NBU’s service area population is projected by then to be 211,110. The current population being served is approximately 102,900.
Expanded SWTP Design Elements will include:
- New raw water pump
- New raw water meter vault
- New rapid mix basin with mechanical mixers
- New rectangular multi-stage flocculation basins
- New rectangular clarification basins with plate settlers and sludge collectors
- Expanded chemical storage and feed systems; optimized chemical storage layout
- New chlorine building with a dry scrubber
- New filters, a new pumped backwash system, and filter-to-waste capability
- New clearwell
- Additional high service pump(s)
- Expanded residuals handling facilities
- Cathodic protection and corrosion-resistance coatings
Site-wide Improvements will include:
- Additional instrumentation to improve process control
- Connection of new equipment to a SWTP-wide SCADA platform with a redundant Historian and upgraded automation and controls, including new control panels and PLCs with redundant processors
- Electrical upgrades including a dual power feed, new MCCs, a new high service pump station electrical building, and a new electrical room in the maintenance building
- Flood resiliency improvements, including elevation and floodproofing of new assets
- Safety improvements
- Additional lighting
- Structural repairs
- Administration building HVAC upgrades
- Continuous sample sink in the laboratory
- New building for predictive maintenance staff offices, storage and workshop
There are cost related issues affected by this project, but they are not within the scope of the TWDB loan package. NBU will have to expand their distribution system piping leaving the plant in order to distribute the additional water that is produced. Electrical upgrades may also be required, including providing dual-power feed to the SWTP to serve as an emergency backup during a power outage (an additional electrical service line is available nearby). Paying for those upgrades will be conducted throughout the NBU water supply system, as needed.
adolfo@virtualbx.com
