Guidelines for Minimum Standards in Water Well Construction, Province of British Columbia — June 1982
Part 1
4. Guidelines for Well Screens and Artificial Filter Pack Construction
4.1 General Considerations
It is recommended that wells drilled into unconsolidated formations be completed using a well screen from a recognized manufacturer. Information on screens, aperture size selection and when to use an artificial filter pack around the well screen are given in Appendix 2. For domestic wells under certain conditions when the water-bearing formation consists of gravel, slotted casing or an open bottom construction can very occasionally be used with drilled wells provided the well does not pump sand.
5. Guidelines for Well Grouting
5.1 General Conditions
Grouting is required for:
- Aquifer protection: to stop ground water movement between two aquifers.
- Well protection: to stop unwanted water entering from the surface or a subsurface zone.
- Casing protection: for example, where corrosive water can attack the casing in certain zones.
It is most important that the annular space be sealed to a sufficient depth (15 or more feet depending on conditions) to prevent contamination or pollution by surface waters or shallow subsurface waters where there may be effluent from septic tanks, etc.
Formations encountered during well construction which are yielding ground water of undesirable quality must be adequately sealed off from underlying (or overlaying) water-bearing zones.
Details on grouting are given in Appendix 3.
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