Hickory Aquifer

Hickory Groundwater phase 2 project awareness notice 

The Hickory Aquifer project is an operation that brings groundwater from the Hickory Sands Aquifer, 15 miles south of Melvin, to San Angelo through a 62-mile, 30-inch pipeline. Once the water arrives in San Angelo, it enters the Groundwater Treatment Facility on Metcalfe Street, where the water undergoes iron oxidation and removal, followed by the removal of radium by ion exchange. The water is relatively free of organic contaminants and has a mineral content of 450 milligrams per liter of total dissolved solids.

The Hickory project was funded by a $120 million low-interest loan from the Texas Water Development Board. The loan could only be used on the Hickory project.

The project was initially designed to pump 6.5 million gallons per day to San Angelo, with a treatment capacity of 8 MGD. Originally, the City planned to increase production to 9 million gallons per day in 2026. (Daily water usage in San Angelo is approximately 9 MGD during the winter, when few people water lawns). In 2015, because of extended drought conditions and the availability of unused funds remaining from the original loan, the City Council decided to expand the pumping capacity to 10.8 MGD. Six new wells were completed in June 2016. Today, the project now has the ability to pump 10.8 MGD to San Angelo and has the equipment in place to treat a total of 8 MGD.

Operating the Hickory facility at full production would provide the City with another option to respond to future or continued droughts, although utilization of the 8 MGD production rate would cause the “banked” water to be used more quickly and would impact the City's future production abilities from the Hickory until annual allocations reach their max in 2036.

The current operational strategy is to use approximately 1.5 MGD from the Hickory Aquifer; the remaining water required to meet daily needs will come from existing surface water sources, chiefly O.H. Ivie Reservoir. In a worst-case scenario, the City could produce 8 MGD on a continual basis for five to six years before all the banked water would be used up. Afterward, San Angelo would still be able to use its annual water allocation, which is currently 2,750 acre-feet per year. This amount increases to 5,000 acre-feet per year in 2021, to 10,000 acre-feet per year in 2026, and to 12,000 acre-feet per year in 2036.

San Angelo relies upon Ivie, Twin Buttes and O.C. Fisher reservoirs, and Lake Nasworthy as its water sources, and currently has a 69-month supply of water, assuming the worst-case scenario of no rainfall or runoff. 

Future projects

• Well field expansion: The wellfield now consists of 15 individual wells that have the capacity to pump 500 gallons per minute each (10.8 MGD total). The City has the ability to add up to 20 wells total, so there could be as many as seven new wells installed to complete the project to ensure maximum pump capacity of 12 MGD with spare wells for down time and maintenance. This potential expansion would require upgrading the existing booster pump station facilities.

• Groundwater Treatment Facility expansion: The treatment plant currently has the capacity to treat 8 MGD. The installation of one additional WRT (radium removal) train would bump the treatment capacity to 10 MGD. To reach a maximum capacity of 12 MGD, the installation of two additional WRT trains and an additional pressure filter would be required.

The City of San Angelo staff and Water Advisory Board are considering upgrade options for the Hickory project to increase capacity in the event severe drought conditions continue or worsen.