IS 10500 lists 48 parameters across two tables. Packaged water plants preparing for a BIS licence renewal rarely stumble on the obvious ones. It is the four below that send applications back.
Hexavalent chromium is not total chromium
The standard sets a limit on hexavalent chromium specifically. Reporting total chromium instead is a common error, and it is not conservative in either direction: a sample can pass on total and fail on hexavalent. They are separate determinations and need to be requested separately.
Trihalomethanes appear after you chlorinate
Chlorine reacts with organic matter in the source water to form trihalomethanes, so a raw water sample can be clean while treated water in the filling line is over the limit. Sample at the point of filling, not at the borewell.
The radioactivity panel takes longer than you think
Alpha and beta emitter testing is on the IS 14543 requirement list and it is not a quick turnaround. Plants that leave it until the licence is weeks from expiry end up applying late.
- Plan radioactivity testing at least a month ahead of the renewal date
- Retest after any change of source, not just annually
- Keep the previous cycle’s report: BIS may ask to see the trend
Microbiology has a 24-hour clock
A microbiology sample that reaches the laboratory two days after collection tells you about the courier, not about your water. Sterile bottle, chilled, dispatched the same day. If that is not possible, ask us to draw the sample on site instead.