The Central Ground Water Board's pre-monsoon 2023 samples from Birbhum found fluoride above the limit BIS sets for drinking water in at least one well. It does not mean every borewell is affected, but it does mean yours is worth testing.
Limit: over 1.5 mg/l.
Long use stains and pits teeth (dental fluorosis) and can stiffen bones and joints (skeletal fluorosis).
What to do: RO or activated alumina filters remove fluoride; rainwater, which has almost none, is a safe drinking source when stored clean.
0.73% of the 959 groundwater samples CGWB tested in West Bengal in 2023 had more than 1.5 mg/l of fluoride.
Rainwater carries almost no dissolved salts or fluoride. Stored clean, it is good drinking water, and recharged into the ground it slowly freshens the aquifer your borewell draws from.
Not without testing. In the Central Ground Water Board's 2023 samples from Birbhum, at least one was over the BIS drinking water limit for fluoride. Water from one borewell can be fine while the next is not, so test yours, and treat it with RO if it fails.
Yes, in places: some 2023 samples in Birbhum had more than 1.5 mg/l of fluoride, the BIS limit. Across West Bengal, 0.73% of 959 samples were over the limit.
Get it tested at a NABL-accredited lab or the local Public Health Engineering department. An RO purifier removes salts and fluoride. Harvesting rainwater for drinking, and recharging it into the ground, also helps, because rain has almost no dissolved salts or fluoride.
Source: Annual Ground Water Quality Report 2024 (Report on Groundwater Quality of Shallow Aquifers in India 2024), Central Ground Water Board, tables of districts over the limit for salinity and fluoride. Other contaminants such as nitrate, iron, arsenic and uranium are tested too but are not shown here yet, so a contaminant missing from this page does not mean it is absent.