What are acceptable sealing materials for wells and borings?
Acceptable sealing materials include: • Neat cement (5-6 gallons water per 94-lb sack of Portland cement), • Sand cement (188 lb sand and 94 lb Portland cement with 7 gallons water, or • 10.3 sack mix), and concrete (6 sack mix with aggregate ≤1/5 the radial thickness of the seal). Bentonite is allowed as an additive to cement-based sealing materials at a ratio of up to 6% by weight of cement used, or as a foundation or transition seal. High solids bentonite slurry and bentonite pellets or chips may also be approved by the Environmental Compliance Division (ECD) on a case-by-case basis.
