The Metropolitan Water Reclamation District will spend $75,000 to test ultraviolet disinfection of wastewater at one of its treatment plants -- a move that officials say could help the environment and save money.
"UV replicates sunlight. It's a natural disinfectant," said Pat Young, an MWRD spokeswoman and former commissioner. "It's cheaper because it's not chlorination or chemicals. It protects the habitat and wildlife. It's more healthy."
The district uses chlorine in warm-weather months to disinfect wastewater at its Egan, Kirie and Hanover Park water reclamation plants, which discharge into the Des Plaines River. The district's other four treatment plants, which discharge into the Chicago River system, do not disinfect wastewater.
The MWRD commissioners yesterday approved a pilot program to study ultraviolet disinfection at the Hanover Park plant.
UV technology is more effective at inactivating bacteria and viruses, and it eliminates the need to manage hazardous chemicals, according to a 2007 U.S. Environmental Protection Agency report. But depending on the plant's treatment process, solid materials suspended in the water may decrease the effectiveness of UV disinfection.
The MWRD is testing three processes from different manufacturers at Hanover Park. The pilot program will run during the colder months, when the district is not required to disinfect. In May, regular chlorine disinfection will resume.
The MWRD is one of the country's few large sewage authorities that does not disinfect all of effluent it pumps into waterways.
The MWRD faces increasing pressure from environmental advocates, and from state regulators, to begin doing so. They say the district is required to disinfect under the federal Clean Water Act of 1972, which was designed to support healthy fish and wildlife populations and recreation on the nation's waterways.
The Illinois Pollution Control Board, the agency charged with adopting the state's environmental regulations, is hearing testimony on both sides of the issue and will ultimately determine whether the district must meet higher water quality standards
District officials say installing and operating disinfection equipment would cost nearly $1 billion over 20 years. Further, they say, there's no proof disinfection will cut illnesses among people exposed to river water, and that much of the effluent goes into man-made canals.
"They were never intended to be fishable and swim-able," says spokeswoman Jill Horist.
Also at yesterday's meeting, the board agreed to pay an additional $200,000 to Barnes & Thornburg, the firm that is handling the district's case before the Illinois Pollution Control Board. The district had previously allocated allocated up to $600,000 for that purpose.