EVANGELINE AQUIFER

The Evangeline aquifer is one of the two primary aquifers in the Houston-Galveston region. The aquifer provides groundwater to many communities and industries in the area. Over the years, the Evangeline aquifer has proven to be a good source of high quality water.

The maximum depths of occurrence of freshwater in the Evangeline range from 150 feet above sea level, to 2,250 feet below sea level. The range of thickness of the fresh water interval in the Evangeline is 50 to 1,900 feet. The depth of wells that draw from the Evangeline range from 170 to 1,715 feet deep.

The Evangeline is separated in most areas from the overlying Chicot aquifer by clay beds. Recharge to the Evangeline aquifer occurs by direct infiltration of rainfall in inter-stream, upland outcrop areas and leakage from other aquifers such as the Chicot. The hydraulic conductivity of the Evangeline varies between 20-100 feet/day.

Water quality studies of the Evangeline produced samples that meet the Federal Primary and Secondary Drinking Water Standards. Data shows that groundwater from this aquifer is generally soft and is of good quality when considering taste, odor and appearance. Water quality conditions throughout the aquifer may vary, however it is estimated that wells within the same general location and depth share similar characteristics. A well study for an existing Harris County MUD reports that a deep well that screens the Evangeline aquifer (700 or 750 to 1,250 foot depth interval) may contain a high concentration of iron that would require a sequestriant to keep it from precipitating.