El Dorado Water Hardness & Quality Report (2026)

El Dorado Water Utilities serves El Dorado and surrounding areas in Union County, Arkansas. The utility draws water from 9 wells tapping the Sparta Sand Aquifer, pumping to four treatment plants: Mount Holly, Morning Star, Downtown, and Champagnolle. Treatment involves disinfection with chlorine and other methods standard for groundwater sources. The utility can be reached at 870-862-6451 or P.O. Box 1587, El Dorado, AR 71731, and publishes annual Consumer Confidence Reports at eldoradowater.ruralwaterusa.com and eldoradowater.com.

The Sparta Sand Aquifer underlies the region as a major groundwater formation in south Arkansas, part of the Gulf Coastal Plain. It consists of Cretaceous unconsolidated sands and gravels confined by protective overlying clay layers. Recharge occurs from precipitation infiltrating through these sands and clays. As groundwater interacts with limestone-influenced formations rich in calcium and magnesium minerals, it produces a hard supply. The Arkansas Department of Health Source Water Vulnerability Assessment rates these wells at low to medium susceptibility, with influences from urban runoff, agriculture, and oil and gas activities.

Hard water causes scale buildup in pipes, water heaters, dishwashers, and washing machines, reducing efficiency and increasing energy costs. Soap lathers less effectively, leaving spots on dishes and causing skin dryness. Maintenance tips include monthly vinegar cleaning of fixtures, annual water heater flushing, and installing sediment filters. A water softener is recommended to prevent appliance damage and improve usability. The utility reports 3 contaminants above EPA health-based guidelines with 3 MCL violations; potential issues include salts and metals from oil, gas, and farming activities.