GREATER NOIDA, April 10 -- Following reports of over 500 residents of Ajnara Homes in Greater Noida West Sector 16B falling sick over the past three to four days, allegedly after consuming contaminated drinking water supplied to flats, the Greater Noida authority on Wednesday imposed a penalty of Rs.25 lakh on the builder for its alleged negligence in maintaining the water tanks and other related utilities, officials said.

According to a notice issued by the authority's water department, the inspection carried out on April 7 revealed "poor maintenance" of the underground and overhead water tanks at the society.

"It was prima facie found that the tanks had not been cleaned since a long time, leading to the presence of bacteria and contam...