Red Flint Group well pack media, used in gravel-packed wells, is engineered to ensure uniformity in size. The uniformity and low acid solubility is said to minimize material lost in well development; the sub-angular shape aids hydraulic conductivity by reducing drawdown and improving yield. It is washed, kiln-dried and screened to meet exacting specifications, and it meets or exceeds AWWA A100-97 standard for water wells and ANSI/NSF Standard 61. Red Flint Group, Card No. 255