install a valve in the small bung and position the drum so that the valve is the lowest part of the drum. Let things settle down and then open the valve to let the water off. If the gas has been stored for a while I would give it a good sniff test and then a sticky test. If it smells "not right" or if you get a sticky feel between your fingers then don't use it. The cost of repairs will far exceed the $90 value at the
pump today.