DeRidder Water Hardness & Quality Report (2026)

DeRidder, Louisiana, in Beauregard Parish — the Beauregard Parish seat adjacent to Leesville and Oakdale on the Calcasieu River in southwest Louisiana — receives its water from the City of DeRidder Water Department, drawing from the Calcasieu River through the southwest Louisiana distribution.

The soft 55.5 mg/L hardness and low TDS of 93.5 mg/L reflect the Beauregard Parish Calcasieu River supply's soft Cretaceous character — the Cretaceous Woodbine Formation is largely insoluble sand and shale, while the Tertiary Wilcox Group contributes minimal calcareous mineral content from its sandy coastal plain sediments (compare Leesville LA: 53/89 in Vernon Parish comparable; Oakdale LA: 57/97 in Allen Parish comparable; DeRidder consistent soft from the same Beauregard Parish Calcasieu River Cretaceous insoluble supply). The Calcasieu watershed — Cretaceous Woodbine Formation (insoluble — primary dilutant), Tertiary Wilcox Group (slightly calcareous — primary hardness contributor), and Quaternary Calcasieu alluvium (slightly calcareous — minor TDS).

At 55.5 mg/L with TDS 94, DeRidder's water is soft — minimal scale buildup. Annual descaling is appropriate. The PFAS level of 6.6 ppt is elevated for soft water — a certified drinking water filter with PFAS removal is recommended. Review the City of DeRidder's annual water quality report.