Karst Aquifers: Arbuckle-Simpson Aquifer

The Arbuckle-Simpson aquifer, which underlies more than 500 square miles in south central Oklahoma, is the principal water source for approximately 39,000 people in the cities of Ada, Sulphur, and others in the region. The aquifer is also the source of a number of important springs in the region, including Byrds Mill Spring, Ada's primary drinking water source, and those in the Chickasaw National Recreation Area, the destination for about 3.4 million visitors each year. The U.S. Environmental Protection Agency has designated the aquifer's eastern portion as a Sole Source Aquifer, a mechanism to protect drinking water supplies in areas with limited water supply alternatives.

The Arbuckle-Simpson aquifer consists of limestone, dolomite, and sandstone within the Simpson and the Arbuckle Groups of Ordovician and Cambrian age and can be up to 9,000 feet thick. Rocks of the Arbuckle and Simpson Groups are exposed at the land surface in three uplifts, separated from each other by large high-angle faults. Intensive folding and faulting of a thick sequence of Paleozoic rocks formed the ancestral Arbuckle Mountains. Originally rising several thousand feet above the surrounding plains, the mountains have been eroded to their present-day maximum relief of about 600 feet.

Water is discharged naturally from the aquifer by numerous springs and seeps; much of this discharge becomes the base flow of streams. Springs that issue from the aquifer discharge up to 19,000 gallons per minute. Small karst features can be seen over much of the outcrop area of the aquifer, but human-enterable air-filled caves are found only in a few locations. Some of the springs and caves include unique fauna, including the Oklahoma cave amphipod, an invertebrate known from only four caves, all of which are located in the Arbuckle-Simpson aquifer.

Springs

Artesian Wells

Featured Studies and Datasets

Aquifer-scale studies and the datasets they produce are a key component to understanding how karst aquifers behave, and the quality of water within them.

• Arbuckle-Simpson Hydrology Study — A comprehensive multi-year study of south central Oklahoma's Arbuckle-Simpson Aquifer. It is the most intensive analysis of surface and groundwater relationships ever conducted in Oklahoma.
• Arbuckle-Simpson GIS Layers Data — Compilation of digital data in a shapefile and tabular formats describing the Arbuckle Simpson aquifer and surrounding areas in Carter, Coal, Johnston, Murray, and Ponotoc Counties, in Oklahoma.

Additional Information

Additional information can be found at The Arbuckle-Simpson Hydrology Study.