Metropolitan Water Reclamation District officials say they've chosen a technology solution for disinfecting water that flows from its North Side treatment plant in Skokie into the North Shore Channel that flows through Evanston.
The agency says it will use ultraviolet irradiation with low pressure high output lamps at the plant. At the system's Calumet plant on Chicago's south side the agency plans to use chlorination to disinfect the outflow.
MWRD Executive Director David St. Pierre, in a news release, said differences in the infrastructure and hydraulics at the two plants required the different solutions.
He said the plans, developed by an agency task force, are now expected to cost $109 million for the two plants, less than half of initial estimates.
He says money has already been reserved in the agency's capital improvement program to fund the projects.
The Board’s next steps will be to hire an engineering consultant to do the design work so that construction can start in 2013 or early 2014.
“We want to have construction completed by December 2015 and disinfection in service for the 2016 recreational season,” said MWRD Commissioner Cynthia Santos, the chair of the agency's finance committee.
Agreements with design consultants for each plant will be submitted to the Board of Commissioners for award in April, and final designs will be completed by March 2013. A contract for construction will be awarded by October 2013.
During the design phase the agency plans to conduct a pilot test of the proposed UV system for the North Side plant for at least three months to help win Illinois Environmental Protection Agency approval for the project.
The project is expected to substantially improve the water quality in the North Shore Channel, improving the channel's suitability for recreational uses.