Source, licence and the standard

The readings

Telangana Ground Water Department (Irrigation and CAD), Telangana Open Data Portal

Telangana Ground Water Department - Pre monsoon Water Quality Data: tg_water_quality_2025_premonsoon.csv (Open Government License, India)

Taken: 2026-11-07 · revision 1 · data.opentelugu.org (groundwater-quality)

Not yet confirmed: the readings are read straight from the department's files; shown like this until a person has compared them.

File tg_water_quality_2025_premonsoon.csv, sha256 f4021d0f2813814a02a67676550610e4b0359e5839c0599217be2128309df0f1

What a reading is, and is not

Each value is one sample from one ground water well, taken by the department in one season (pre-monsoon or post-monsoon). Ground water changes with the season and from well to well. Tap water from a supply scheme comes from elsewhere and is treated. A reading says what was found in that well, not whether anyone's drinking water is safe.

The department's files do not state units; values are read as mg/l, the standard's unit (to be confirmed with the department).

The water levels

Telangana Ground Water Department (Irrigation and CAD), Telangana Open Data Portal

Telangana Ground Water Department Water Level Data July 2026: ground_water_level_2026_July.csv (Open Government License, India)

Taken: 2026-11-07 · revision 1 · data.opentelugu.org (groundwater-levels)

Not yet confirmed: the readings are read straight from the department's files; shown like this until a person has compared them.

File ground_water_level_2026_July.csv, sha256 93ec95f53bff7ba952e8b0139d753d6348f2d0d6783fc6e4b58bba2730b2f557

Each level is how far below the ground the water stood in one monitoring well, measured by the department once a month, in metres ("m bgl", metres below ground level, as its file says). The level wells are the water quality wells: they stand at the same coordinates. A well is given a level only where the two lists match it one to one, so a few wells have none.

The limits

IS 10500 : 2012 Indian Standard DRINKING WATER — SPECIFICATION ( Second Revision ), May 2012

• pH value: 6.5–8.5 (Table 1, iii)
• Total dissolved solids: 500 / 2000 mg/l (Table 1, vi)
• Calcium (as Ca): 75 / 200 mg/l (Table 2, vi)
• Chloride (as Cl): 250 / 1000 mg/l (Table 2, viii)
• Fluoride (as F): 1 / 1.5 mg/l (Table 2, x)
• Magnesium (as Mg): 30 / 100 mg/l (Table 2, xiii)
• Nitrate (as NO3): 45 / — mg/l (Table 2, xvi)
• Sulphate (as SO4): 200 / 400 mg/l (Table 2, xx)
• Total hardness (as CaCO3): 200 / 600 mg/l (Table 2, xxiii)

It is recommended that the acceptable limit is to be implemented. Values in excess of those mentioned under ‘acceptable’ render the water not suitable, but still may be tolerated in the absence of an alternative source but up to the limits indicated under ‘permissible limit in the absence of alternate source’ in col 4, above which the sources will have to be rejected.

IS 10500:2012 is "© BIS 2012". Only the limits of the rows used (facts), each cited to its table and row, and the tables' note on acceptable and permissible limits are given here; the standard itself is not copied. Read from the copy the National Consumer Helpline (Department of Consumer Affairs) publishes.

Attribution

Published on the Telangana Open Data Portal under the "Open Government License, India" (the dataset's licence field), taken as the Government Open Data License - India (GODL, Gazette of India, 13 February 2017): use, adapt and publish, with attribution of the provider, source and licence. Figures as the file gives them.

Why only two seasons

The department sampled about 360 wells up to 2020 and about 1,020 from 2021; from post-monsoon 2024 it samples 1,771. The older wells cannot be matched to today's by name, so their readings are not shown beside them.

Andhra Pradesh

We have not found an open, well-by-well file of Andhra Pradesh's ground water quality or levels like Telangana's. The Central Ground Water Board's well data may cover both states; it will be added here once its files and terms have been checked.