The village of Carpentersville started supplying water to part of West Dundee this week after West Dundee officials temporarily closed the Randall Road water tower for a weeklong cleaning.
The water tower, also called Well 6, contains the highest amount of hydrogen sulfide from among the village's three wells. It's a naturally occurring gas in the raw water supply that makes it smell like rotten eggs, Village Manager Joe Cavallaro said.
Earlier this summer, the West Dundee village board approved several measures to tackle the problem, which also exists to a smaller degree at Well 5 at the public works facility on Angle Tarn.
Officials reiterated their plans in a Friday Facebook posting after a resident complained about odor on the village's community page.
When it comes to Well 6, the village said it is:
• Cleaning, inspecting and installing a mud valve, as well as temporary equipment and mixer system to stir the water tower. That will cost $22,000.
• Developing plans and specifications for the installation of permanent equipment and hydrant flushing stations in the most problematic areas of the village.
Officials also inject chlorine into the water during the treatment process to help kill off the smell, Cavallaro said.
The problem is higher temperatures outside cause the chlorine to break down faster and the hydrogen sulfide returns, forcing the village to add more chlorine, but never more than the Illinois Environmental Protection Agency allows, Cavallaro said.
"It's a balancing act," Cavallaro said. "It's a water quality issue where we want to do our best to make sure that the overall quality that we are getting out to the community is consistent."
Officials plan on modifying the chlorine system at the Randall Road Water Treatment Plant so it adds chlorine before the water distribution process, rather than after the treatment process. That will cost $30,000.
The village receives complaints about the stench from 100 households, mostly in the Grand Pointe and Carrington Reserve subdivisions on the west side of town, Cavallaro said. The village has approximately 4,000 water billing accounts.
Carpentersville's Randall Road water tower is supplying water to the western portion of West Dundee as part of an intergovernmental agreement the towns formed several years ago. At the time, of the agreement, Carpentersville was repainting its own water tower and needed to use West Dundee's water on the west side of its village, Cavallaro said.