Water Treatment Plant Improvements
Water Treatment Plant Upgrades
The City of Granbury has a three phase plan to be able to provide drinking water for the community and meet the future needs of Granbury’s growing population.
Phase I of the project, which involved the construction of a new Surface Water Treatment Plant that can produce up to 2.5 MGD, was completed in January of 2018. This meets Granbury’s current daily water requirements (approximately 1.5-2 MGD), except on peak demand days (3-3.5 MGD) when water supply from the City’s 34 groundwater wells will supplement demand.
At the May 15, 2018 Granbury City Council meeting, Council approved the $13.5M Engineering Services Agreement with Enprotec/Hibbs & Todd, Inc. to proceed with Phase II of the project.
Phase I: 2.5 million gallons per day – finished January 2018 (read news release)
Phase II: 5.0 million gallons per day – approved to begin in May 2018 (read news release)
Phase III: 7.5 million gallons per day – as needed, based on capacity projections
The Surface Water Treatment Plant upgrades are designed in three phases. Phase one, which is now complete, can produce up to 2.5 MGD (million gallons of water per day). This meets Granbury’s current daily water requirements (approximately 1.5-2 MGD). On peak demand days (3-3.5 MGD), water supply from the City’s 34 groundwater wells will supplement demand.
In phase two, which is in the process of being implemented, additional equipment will be installed in the plant. This upgrade will increase the capacity of the plant to 5 MGD.
Phase three will increase capacity to 7.5 MGD, and will be implemented in the next 20-30 years, depending on population growth.
How the Plant Operates
The floating raw water pumps send water from Lake Granbury into the system, where the treatment process begins. The water travels through a pre-treatment phase in which chemicals and plate settlers assist with the removal of solids and pathogens.
After the chemical pre-treatment, the water travels to the microfiltration system, which removes anything that could be seen with the naked eye from the water. To do this, water is pushed through holes in tiny, straw-like filters, where dirt and other solids attach to the walls of the filter.
The result is called filtrate. It is clean, safe to drink, and meets all state regulations. However, this plant takes the water another step.
The filtrate is then pumped through a semi-permeable membrane, known as a reverse osmosis filter. This process removes inorganic solids, such as salts.
Following reverse osmosis, the water is combined with a percentage of filtrate, and moved into holding tanks. From there, the water is pumped into the City distribution system for consumption.