IS 10500 is the Indian standard for drinking water. A full test covers physical, chemical and bacteriological parameters, each with an acceptable limit and a permissible limit in the absence of an alternate source. We report all three groups on one report with the method used for each.
The limits below are those specified in IS 10500. "No relaxation" means the permissible limit is the same as the acceptable limit — there is no second tier.
| Parameter | Unit | Acceptable limit | Permissible limit | Group |
|---|---|---|---|---|
| pH value | — | 6.5 – 8.5 | No relaxation | Physical |
| Turbidity | NTU | 1 | 5 | Physical |
| Total dissolved solids | mg/L | 500 | 2000 | Physical |
| Total hardness (as CaCO₃) | mg/L | 200 | 600 | Chemical |
| Chloride (as Cl) | mg/L | 250 | 1000 | Chemical |
| Sulphate (as SO₄) | mg/L | 200 | 400 | Chemical |
| Iron (as Fe) | mg/L | 1.0 | No relaxation | Chemical |
| Fluoride (as F) | mg/L | 1.0 | 1.5 | Chemical |
| Nitrate (as NO₃) | mg/L | 45 | No relaxation | Chemical |
| Arsenic (as As) | mg/L | 0.01 | 0.05 | Chemical |
| Lead (as Pb) | mg/L | 0.01 | No relaxation | Chemical |
| Total coliform | MPN/100 ml | Shall not be detectable | No relaxation | Bacteriological |
| E. coli | per 100 ml | Shall not be detectable | No relaxation | Bacteriological |
The report tells you which parameter exceeded which limit and by how much. That is what a plumber, an RO vendor or a consultant needs to size a fix. We do not sell treatment equipment, so the result carries no commercial interest for us. In Kolkata the two most common failures we see are iron in borewell water and coliform in overhead tanks that have not been cleaned — different problems with completely different remedies.
Both, if you are diagnosing a complaint. A clean reservoir with a contaminated tap points at the internal plumbing; contamination at both points at the source or the tank. Testing only one point tells you there is a problem but not where it is.
No. A TDS meter measures dissolved solids and nothing else. It cannot detect arsenic, lead, fluoride, nitrate or bacteria — the parameters that actually cause harm. Low TDS water can be unsafe and high TDS water can be safe.
For a routine safety check, the bacteriological pair plus pH, TDS, hardness and iron answers most questions cheaply. For a formal submission or a health concern, run the full panel including heavy metals.
Quick check of total dissolved solids in tap, borewell, RO and packaged water. Handy for seeing when RO filters need changing.
Lab note: Measures dissolved salts only. It cannot detect bacteria, arsenic, lead or pesticides.
Check price on AmazonChecks residual chlorine in municipal supply, overhead tanks after cleaning, and chlorinated well water.
Lab note: Colour comparison; test immediately after collecting the water.
Check price on AmazonFor high-TDS borewell or tanker water, where dissolved salts need to come down.
Lab note: RO is not needed if your water TDS is already low; check TDS before buying.
Check price on AmazonFor municipal or low-TDS water where the main concern is germs, not dissolved salts. Wastes no water.
Lab note: UV does not remove dissolved salts, fluoride or arsenic.
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