The water samples should be tested in the NABL (National Accreditation Board for Testing and Calibration Laboratories) accredited labs, Paswan said in tweet.
He further said that the BIS will conduct a workshop for water supply officials of states on December 9 and asked the Delhi chief minister to send his officials to attend it.
Paswan in his letter also objected to questions being raised against the survey conducted by an organisation of internation repute like the BIS, and said Kejriwal himself has acknowledged that poor quality water was being supplied in some colonies.
The Union minister reiterated that the BIS conducted water quality survey in capitals of 20 states.
Paswan said any test conducted by the state government would not be acceptable to the BIS.
If water quality has to be tested again in the national capital, then a joint committee of the BIS and the DJB should be formed, he demanded.
Last week, Paswan launched a blistering attack against Kejriwal for politicising the water quality issue, saying "baseless allegations" are being made against him and challenged the Delhi Chief Minister to make BIS standard mandatory if water supplied in the national capital is 100 per cent pure.
He criticised Kejriwal for raising questions about the credibility of the Bureau of Indian Standards (BIS), an autonomous body that has developed around 25,000 quality standards for various products and services.
The war of words between the two began soon after a BIS study said that drinking water quality in the national capital is among the worst in the country.
Paswan said that a committee, comprising technical officers from the BIS and the Delhi Jal Board (DJB), should be set up immediately to take samples from across 70 constituencies and 140 wards in the national capital by end of this month. MJH MKJ