When you turn on a faucet right now in your Granbury home or business, the water is most likely coming from the City’s newly-opened Surface Water Treatment Plant. The new plant’s capacity is 2.5 MGD (million gallons of water per day) using microfiltration and reverse osmosis methods that treat the water in Lake Granbury.
The City’s previous water treatment facility (which has now been demolished) was constructed in 1985, and unable to meet Granbury’s current water demands. Water needs were supplemented with groundwater wells and by purchasing water from the Brazos River Authority Lake Granbury Surface Water Advanced Treatment System Plant.
In building a new water treatment plant, the City can now provide the amount of water the community needs and ensure a much higher quality of drinking water. Water from the new plant contains fewer minerals, which will give it a better taste and prevent the white residue that hard water causes. The plant is secure and camera-monitored, and all water from the plant meets Texas Commission on Environmental Quality (TCEQ) requirements.
“It is very exciting to see the vision of the City Council come to fruition,” said Public Works Director Rick Crownover, “The water treatment plant is a valuable asset to the community that will improve life for Granbury residents for many years.”
Planning and research for this project has been ongoing for about a decade. On June 2, 2015, Granbury City Council adopted an ordinance authorizing the issuance of certificates of obligation in the amount of $16.4M for the purpose of building a new surface water treatment plant. Following the bidding process, construction on the new water treatment plant began in February of 2016.
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 you would be able to see 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 State regulations. However, this plant takes the water another step.
The filtrate is 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.
Three Phases of Upgrades
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 will likely take place within the next ten years, 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.
More information about the exact makeup of City of Granbury water is available in the Annual Drinking Water Quality Report: www.granbury.org/DocumentCenter/Index/73.
In conjunction with the water treatment plant project and expansion of surface water supplies, the City must make improvements to its existing water distribution system to allow for the introduction of this expanded water supply into the distribution system. To read about these additional improvements to the water distribution system, visit www.granbury.org/831/Water-Treatment-Plant-Distribution-Proje.