City hustles to add new treatment tool to improve Bloomington's water taste and odor

Bloomington officials say they fast-tracked the installation of a new tool this week that should help improve the funky taste and odor of the city’s water supply.

The city has begun adding powdered activated carbon [PAC] to its water system. The PAC will be fed into the raw water at the city’s water treatment plant where it will remove contaminants, like organic chemicals, by adsorption. The PAC with the adsorbed contaminants is then removed from the water and discharged. The result should be better smelling and tasting water. 

“These steps will help, but it will still take time for the effects of the PAC to reach homes in Bloomington,” Water Director Ed Andrews said in a statement on Thursday. 

Bloomington residents and businesses have experienced “prolonged high levels of taste and odor compounds” coming from its two surface water sources [Lake Bloomington and Evergreen Lake] for weeks. As part of the response, the Illinois EPA recently granted the city an emergency permit to operate a temporary PAC system, officials said.

Instead of waiting for a PAC shipment to arrive, city officials said they sent a semitrailer truck to West Virginia to pick it up directly — “getting it here with a 24-hour turnaround.” The PAC started going into the water system Wednesday afternoon, city officials said. The city expects to increase the amount of PAC going into the system to reach the ideal level.

Installation of the temporary PAC system was done in anticipation of a permanent PAC system.

That’s now being accelerated, too. The Bloomington City Council is expected to vote Monday night on the purchase of a $755,132 permanent PAC feed system from Chemco Systems Inc. The city already had planned to buy a new PAC system next fiscal year, but it’s now opting to accelerate the purchase, officials said.

Here’s how the new system will work, according to a memo shared with council members: “The PAC storage and feed system is enclosed in a silo which is divided into two main compartments. The upper compartment is for receiving shipments and storage of PAC. The lower compartment houses the feeding equipment where a precise amount of dry PAC is mixed with water to form a slurry, and a water-powered eductor [pump] conveys it to the point of application at the raw water main just outside the treatment plant.” 

City officials said they’ve made other changes as well to improve taste and odor issues. That includes adding more filters — from the original eight up to a planned 16.