CHARLESTON, W.Va. -- Water plants from Ashland, Ky., to Cincinnati are shutting their intake pipes along the Ohio River as a 60-mile-long plume of licorice-scented contaminants from last Thursday's chemical spill from a storage tank along the Elk River in Charleston float past.On Tuesday, the plume passed the Ohio River town of Maysville, Ky., 143 miles downstream from Charleston."People in Maysville were smelling the stuff this [Tuesday] morning," said Jerry Schulte, manager of water protection and emergency response for ORSANCO, an interstate commission charged with protecting and improving water quality in the Ohio River and its tributaries.ORSANCO maintains a series of monitoring stations along the Ohio in conjunction with industries and water treatment plants located along its shores. The system was established in response to a 1977 tetrachloride spill from the FMC plant in South Charleston that entered drinking water systems along the Kanawha and Ohio Rivers as far downstream as Cincinnati."We estimated the plume to be about 60 miles long as it went past Huntington," said Schulte "It may be longer now. The concentration of MCHM [the substance released in the spill] will lessen and the length of the plume will lengthen as it moves downstream."The plume entered the Ohio River at Point Pleasant about noon on Sunday, and floated past Huntington later in the day. According to West Virginia American Water officials, the concentration of MCHM entering Huntington's water treatment plant was 0.031 parts per million, which dropped to 0.006 ppm as it entered the water system after treatment.The federal Centers for Disease Control set 1 ppm as the maximum acceptable concentration of MCHM for use in water systems.Early Monday, officials at water systems serving the Ashland and Russell, Ky., areas shut their Ohio River intakes, and used stored water and secondary water sources to give their customers uninterrupted service as the plume floated past.The plume was expected to reach Cincinnati sometime between 7 and 9 p.m. Tuesday, according to officials at the Greater Cincinnati Water Works, who planned to shut the water system's Ohio River intakes as a precaution.No interruption in service was expected, since the utility has access to a secondary water source from wells in a nearby community.Across the Ohio River from Cincinnati in Erlanger, Ky., the Northern Kentucky Water District, which serves about 300,000 customers, made plans to close its Ohio River water intakes at two of the riverfront water plants it operates. No interruptions in service were expected.The chemical plume is expected to reach Louisville on Friday. Water company officials there have not yet decided whether they, too, will close intake valves as the remnants of the West Virginia chemical spill flow past, according to Dick Brown, a spokesman for the Kentucky Department for Environmental Protection.Schulte said there was no evidence of harm to aquatic life in the Ohio as a result of the spill."We'll keep monitoring it downriver as long it has the potential for causing harm," he said. "This is the first experience I've had with this material."Reach Rick Steelhammer at firstname.lastname@example.org or 304-348-5169.