City and utility officials know that manhole covers are disappearing from the streets — some 2,050 from Philadelphia alone in just the first seven months of 2008.The question is what to do about it. Officials across the country are taking a wide range of steps to curtail theft, from installing security locking devices, to replacing high-value iron covers with plastic covers that have little or no worth on the scrap market, to passing laws that require metal recyclers to identify those who sell materials to them.It’s all because the value of scrap metals — including the cast iron that most
