When someone talks about the extensive aquifer that supplies the High Plains, they usually think of the Ogallala, an aquifer that stretches from North Dakota to Texas. However, the deepest source of potentially useable groundwater in the High Plains is not the Ogallala, but the Dockum Aquifer.
“Right now, we have an ocean of water underneath us called the Dockum Aquifer,” said Rudy Ritz, Ed.D., an associate professor in the Department of Agricultural Education and Communications at Texas Tech University and a research partner with the Texas Alliance for Water Conservation.
The Dockum Aquifer lies directly underneath the Ogallala Aquifer, reaching depths of 314 feet to a staggering 1952 feet, about twice the height of the Empire State Building. This “minor” aquifer has the potential of being a major source of water for the High Plains. A setback for using the aquifer’s full potential is the water composition, with a large portion of the water so brackish it’s greater than sea water salinity levels.
Several factors go into play to determine the usability of a water source: salinity, hardness, radioactivity, location, and ease of withdrawal. Water drawn from the center of the Dockum is heavy with saline and uranium, making it unusable for agricultural and urban use. However, this water is great for mining, electricity generation, and water flooding, a practice used in the oil industry to extract oil up to the surface.
“Water flooding is where you have water injection wells spaced out around your oil wells,” said Kristofer Aasen, a drilling engineer at CrownQuest. “These water wells are injecting produced water into the production zone. In turn, displacing the oil that’s in the formation hopefully towards your oil producing well.”
“It can resolve getting rid of produced water while also fully depleting the reservoir and giving you more oil if done correctly,” said Aasen, who earned a bachelor’s degree in petroleum engineering from Texas Tech.
Oil companies in the past used water from the Ogallala Aquifer for water flooding, but with the depleting levels, they have drilled into the Dockum, preserving the remaining amounts of the Ogallala water for irrigation and municipal use.
In the northern and eastern areas of the underground sea, researchers have found that the salinity and hardness levels of the water in the Dockum are diluted enough to use for crop and livestock production. Opening an additional water source in a region where every drop counts, there are 336 wells spread in over 40 counties.
The Dockum Aquifer could be an answer to the water scarcity issue plaguing the High Plains, but wells are expensive to drill, as they must go 1,500 feet or more below the surface to tap into the aquifer. Some counties are blending water from the Dockum with water pulled from the Ogallala, creating a blend suitable for both agricultural and urban use.
Ritz is optimistic that in the future, researchers and innovators can find a way to efficient way to use water from the Dockum for agricultural use.
“If we can figure out how to clean that water up and use it for agricultural production, we would be able to sustain and even improve what we’re doing, not just for production, but all these municipalities,” Ritz said. “If we could become innovative in our approach to providing water, there’s a lot of water out there.”