Siloam Springs Water Hardness & Quality Report (2026)

Siloam Springs Waterworks provides drinking water to the city of Siloam Springs in Benton County, Arkansas, near the Oklahoma border. The utility draws from groundwater sources tapping the local aquifer, with treatment carried out at facilities managed by the department. The system serves approximately 17,000 residents through a municipal distribution network maintained in compliance with EPA standards. Annual Consumer Confidence Reports are published on the city's official website, providing detailed documentation of water quality parameters, treatment methods, and regulatory compliance.

The watershed encompasses the Illinois River basin within the Ozark Plateau, where groundwater is recharged through karst topography. Water interacts with Mississippian-age limestone and sandstone formations of the Springfield Plateau Aquifer, dissolving minerals that shape its chemistry into a moderately mineralised profile. This geological influence produces a supply with notable dissolved solids, distinguishing it from softer surface waters elsewhere in the state.

Moderately hard water causes moderate scale buildup in appliances like water heaters, dishwashers, and washing machines, reducing efficiency and lifespan, with spots on glassware and soap scum in bathrooms. Regular maintenance includes vinegar descaling quarterly; a water softener is recommended to protect plumbing and mitigate these effects. The utility maintains strong compliance with EPA legal limits, though independent health guidelines flag concerns with bromodichloromethane, chloroform, chromium (hexavalent), and radium; source water vulnerability is rated low by the Arkansas Department of Health.