As part of a federally mandated plan to improve Aurora's combined sewer system, the city will install rain gardens at 28 intersections to filter stormwater before it enters sewer pipes.
The $1.7 million project will be supported by $1.4 million in reimbursements from the Illinois Environmental Protection Agency. The rain gardens will be designed by Hey and Associates of Aurora under a $33,075 contract the city council approved Tuesday night.
The contract is just one part of a $120 million long-term plan to help reduce the number of sewer overflows at 17 locations in Aurora to below the federal standard of four a year.
Aurora was required to file such a plan by April 2011 because it is one of 108 municipalities in Illinois and 772 nationally that have combined sewer systems where sanitary sewage and stormwater flow to treatment facilities through the same pipes.
Rain gardens will help with implementation of the plan because they use the long roots of native plants to purify and absorb some rainfall, decreasing the amount entering the sewer system after each storm.
As the council approved the landscape architecture contract for the new rain gardens, aldermen also approved a separate agreement for maintenance of four native plant areas already in place.
Alderman Rick Lawrence and Mayor Tom Weisner both said they have concerns about upkeep of the native plant areas, including landscaping at the Aurora police headquarters; a bioswale behind the city's combined sewer treatment facility at 400 N. Broadway Ave.; rain gardens on Spring Street between Fourth and Root streets; and a stormwater basin near the Metra parking lot at Lincoln Avenue and Spring Street.
"We're new to it; we're inexperienced with it," Weisner said about maintenance of rain gardens and native plant areas. "I think bringing in a professional will help."
ENCAP, Inc. of Sycamore, a contractor specializing in ecologically sensitive and water-related projects, will maintain the areas for the rest of 2012 and all of 2013 under a $62,670 contract also approved Tuesday night. The company will control and remove invasive vegetation, apply herbicides, prune native plants and remove trash, brush and other debris from the existing native plant areas.
Public Works Director Ken Schroth said more than 50 percent of the contract with ENCAP will pay for maintenance of plantings at the Aurora police headquarters. But upkeep of the native plants still costs less than maintaining the same amount of grass, he said.