Three recent deaths two in Malad and one in Vasai seem to have woken up BMC to the menace of potholes. A test conducted by the civic body has revealed that 25 per cent of the cold mix used to repair potholes is substandard,indicating malpractice and misappropriation of funds by contractors. To ensure quality,BMC will now conduct regular sample tests and fine corrupt contractors. After repeated complaints,the civic administration had sent 25 cold mix samples collected from across the city for testing. In a marshall stability test to check bitumen content,density of the mix and the load the specimen can take at a specified temperature,over 15 per cent of samples failed to meet requirements of standard cold mix. We found 25 per cent of the samples substandard. We are penalising four contractors, said S V R Srinivas,additional municipal commissioner. Of the more than 15,000 potholes reported on the BMC tracking website since June 2013,11,732 have been repaired. Every monsoon,the civic administration spends at least Rs 60 crore on pothole repairs through contractors. Cold mix was introduced by BMC last year to replace the conventional hot mix that would wash away in rain. Meanwhile,traffic police inspectors in charge of 25 posts claimed despite writing more than 150 letters in the past two months drawing attention to potentially fatal potholes BMC had failed to respond.