Generally, the following steps are followed. They may however differ slightly from service provider to service provider. The client may also influence some elements.
- Drilling of 11”until loose top formation and installing 9” temporary casing, then drilling 8” up to recommended depth.
- Casing: Installation of 6” casing pipe – Class – B ( 4.5mm thickness ) up to bottom. Generally ratio of plain casing and screen casing is 70:30 but depends on the hole drilled.
- Gravel Pack: Inserting 2-4mm natural gravel outside the casing and inside the open hole for artificial filtration.
- Development: This is done by air jetting until clean water emerges. Generally, this can take up to 3 hours but may vary with the hole.
- Well head Slab: This is done using cement, sand and gravel in proper ratios to prevent contamination of the hole.
- Capping: A cap is fitted over the hole until installation of pump.
- Test pumping: This is done to measure the exact yield of the borehole. The water needs to be pumped out continuously for 24 hours. It is then possible to tell the yield of the well, rest level and pumping water level. This is important in determining the size of pump to be installed. On the basis of test pump report, one can decide the pump installation depth, size of pump, motor, delivery pipe, cable, control panel, water meter and other sundries.
- Water chemical and bacteriological analysis is then done by government chemist to assess if the water is suitable for domestic/industrial use or not.
- Completion Report: A completion report is then filed with WRMA and a copy availed to the client.
If these step are followed to the latter then you can be guaranteed a quality borehole.
