Lindenhurst sewer plant shaping up for spring completion

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Updated: March 26, 2012 1:58AM

All the heavy equipment and workers at the Lindenhurst wastewater treatment plant are transforming it into a state-of-the-art facility that will be completed and operating later this year.

Residents saw a 9.5 percent increase, or about $5 monthly, in their water and sewer bills last year to help fund the $10.5 million treatment plant upgrade, required by the Illinois Environmental Protection Agency. Costs are being shared by the sanitary district and the village.

As part of the treatment plant upgrade, the original plant built in 1969 close to Grass Lake Road and south of the newer treatment facility will be decommissioned and demolished. The newer facility built in 1991 and expanded in 1998 was designed to accommodate this third and final expansion that will increase daily treatment capacity to two million gallons.

“We are about seven months into the 11-month project,” said Wes Welsh, director of public works. “It’s getting kind of crazy at the site with workers and equipment, but it is going really well.”

Many of the new features of the plant are being accommodated within the older facility. New additions to the two-acre site include two stormwater detention basins, a biosolids storage area and an additional oxidation ditch.

The existing sludge tanks are being repurposed into aerobic digesters and the sand filters are being replaced with more efficient cloth filters.

From start to finish the new plant will treat sewage without using any chemicals, said Welsh, explaining treatment starts with sewage that comes into the plant first flowing through a bar screen to filter out any large debris that could damage pumps. It goes into an oxidation ditch where oxygen is added to the waste. It is then sent to a clarifier where clear liquids rise to the top and the solids are sent into aerobic digesters for further treatment.

“The digesters introduce good bacteria that literally digests the bad bacteria and reduces the volume of the waste,” said Welsh.

The digested sludge is sent into a centrifuge where liquids are spun out and the remaining sludge is reduced to the consistency of wet sand. The thick sludge is stored until it can be hauled away and applied to farm fields; the clear effluent that is spun out undergoes UV disinfection and is discharged into Hastings Creek. “Anything that goes into the creek meets IEPA standards,” said Village Administrator Matt Formica. “We will not be discharging dirty water.”

This expansion brings the plant to its ultimate capacity. Incorporating state-of-the-art technology that eliminates chemicals means it will be environmentally friendly with reduced operating costs, said Formica.

“In terms of capacity this should continue to serve our residents far into the future. The buildings and other structures have a life span of at least 50 years and the equipment should last about 20 years. In terms of major improvements, absent new required standards, this plant should serve us for many decades.”