Groundwater Quality Trend Maps

In the groundwater database, there are 25083 water samples in Lea, Eddy, and Chaves counties. These samples have a wide range of sample dates and include many water wells designated for various uses, including stock, irrigation, domestic, mining of ore, oil, gas, and many others.

Surface Water Chloride concentration maps show the groundwater samples by formation with chloride concentration in mg/L. Note the legend below.

Surface water Quaternary Alluvium Ogallala Cretaceous Triassic Ochoan Artesia Group Reef Delaware Mtn Group San Andres Leonardian Pre Permian (Pennsylvanian and Devonian) Other / No Formation

In general, shallow groundwater samples are found in formations at or near the surface, and have low chloride concentrations, with the majority of samples having a chloride concentration of less than 1000 mg/L. Their high quality most likely reflects their origin as meteoric water and short residence time within the aquifer. A noticeably higher chloride concentration occurs near the Pecos River, indicating possible upward movement of deep groundwater towards a topographic and potentiometric low.