The Dalles City Council has asked municipal staff to put up warning signs on Mill Creek about E. Coli contamination if its source is not found by Friday.  Mayor Steve Lawrence expressed frustration that no one has stepped up to take responsibility for rectifying the problem that has lingered since the fall.  Lawrence added the City has agreed to dig in the area where it is believed the problem might be located if the North Central Public Health District can’t find it by the middle of next week.  Lawrence noted some senior residents in the area have said the source of the contamination could be an old pipe from a spring on the nearby hillside to collect water and prevent erosion.