Projects
North Elevated Storage Tank
Location:
Melissa, TX
Expertise:
Construction, Transportation
Services:
Construction Materials Testing and Inspection, Geotechnical Engineering, Project Management & Construction Administration, Roadway Design, Survey
Melissa, Texas is a rapidly growing community on the north side of the Dallas Metroplex. To meet its required future water needs, the city is in need of fast-track construction of the new 2-million-gallon North Elevated Storage Tank (NEST). Our firm is helping the City of Melissa make the new NEST a reality on schedule and under budget, two concerns that the city expressed.
The vision for this project is to create a signature monument promoting the community, as well as serve as a central structure for a municipal complex with several floors and usable interior space. Additional design features included fire sprinklers, heightened security, outdoor lighting, and sanitary sewer service in the tower. Operationally, the city wanted to be able to reverse the water flow direction from the distribution system back into the water tower, as needed.
The tower is fed through chlorinated water purchased from the Greater Texoma Utility Authority (GTUA). The GTUA requires an air gap between the two systems, eliminating all bypass pumping options. The water is purchased through the Texas Commission on Environmental Quality (TCEQ) and requires on-site chloramine boosting, chloramine monitoring, and tank mixing. Chloramine chemical delivery and storage is provided in the tank pedestal.
To predict the influence of the water tower on the distribution system, our firm revised the city’s existing water model. It can now extend period duration simulation to verify the performance of the current distribution system. We added the proposed elevated storage tank, performed an extended period simulation to confirm the tank size and overflow elevation to achieve the desired impacts.
With aesthetic and functional qualities in mind, our firm designed the new 2-million-gallon pedestal-style North Elevated Storage Tank. As a composite tower, it has an impressive appearance with lower life-cycle costs for operation and maintenance. The NEST’s concrete pedestal includes three interior floors, with the top two for storage and a multi-use bottom floor housing the chlorination system – complete with HVAC, spill protection, negative pressure venting, and fire suppression systems. To allow maximum operational flexibility, the NEST was designed with separate inflow and outlet pipes capable of reversing and measuring flow from the distribution system back into the water tank. Due to the required air gap, the chlorination system was integrated with a mixing system that allows the chloramine booster to inject directly into tank to ensure water quality. This design feature simplified the chlorination system with the added benefit of tank mixing, allowing the system to accept water with various levels of chlorination.
Our firm completed the civil design, tower design, process piping and chlorination system/process design. We coordinated the electrical, mechanical, civil, mixing system, and fire protection engineers to author the engineering report, design specifications, and complete permitting the project with TCEQ. After the project was approved, we helped the City of Melissa during the bidding and award process. Landmark was selected as the tank provider, and we continued construction management and coordination.
We provided construction drawings and cost estimates, and construction administration, inspection, and testing services for the new City operations facility, providing drives and utility design on the City property to accommodate future buildout of the property.
