Well Product Functions Evaluated Under NSF/ANSI/CAN 60

The function names used by NSF are as follows:

• Drilling Fluid
• Well Drilling Aid
• Foaming Agent
• Well Sealant.

These functions apply to drilling and development of drinking water wells. The evaluation process includes parameters for water used to drill the borehole, residual product in the aquifer, and flushing the well prior to placing it into service. The chemical products and their accompanying contaminants shall not exceed the applicable health effects criteria when evaluated under these conditions.

Drilling fluids

Drilling fluids for drinking water wells are composed of water mixed with clays (e.g., bentonite), polymers or other additives. The pumped drilling fluid carries the cuttings out of the borehole and cools the drill bit.

Well drilling aids

Well Drilling Aids are chemical products added to a water-based drilling fluid. Standard 60 splits the evaluation of Well Drilling Aids into non-turbid and turbid additives, which distinguishes the cloudy or opaque drilling aids (e.g., bentonite) from clear additives (e.g., polymers, caustic soda).

Foaming agents

Foaming agents are used during air drilling (no water-based drilling fluid) to increase the rate of cuttings removal from the borehole. These chemical products are evaluated the same as non-turbid Well Drilling Aids, except that a “foaming factor” is added to account for increased volume by incorporating air.

Borehole sealants

Most common clay (e.g., bentonite) or cement materials are used for sealing and grouting drinking water wells. They prevent surface water from traveling down the exterior of the well casing and contaminating the aquifer and reduce corrosion of the well casing.

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