The Crest Hill City Council is continuing to review options for short-term remediation of “forever chemicals” in the city’s drinking water.

Residents and business owners were informed in April by the Illinois Environmental Protection Agency that testing of the city’s water had revealed excessive levels of per- and polyfluoroalkyl substances, also known as PFAS, in several of the city’s eight functioning wells.

According to the IEPA, PFAS are “a group of several thousand human-made chemicals that are manufactured for their oil- and water-resistant properties” and are found in various everyday products.

Illinois implemented standards defining safe limits for the presence of six chemicals in groundwater in 2021. Two of those chemicals, perfluorooctanoic acid (PFOA) and perfluorohexanesulfonic acid (PFHxS), were found in high quantities in Crest Hill’s wells, including a PFOA level that is more than three times the regulated limit in some places.

While the city has repeatedly said that the long-term solution to the problem is already underway in the transition to Lake Michigan water from Chicago, that project is not expected to be complete until mid-2030.

In the short term, the chemicals still can pose a risk to consumers’ health, and the EPA has mandated that municipalities address high levels by April 2029.

Filtering out PFAS completely from the city’s water was investigated before Crest Hill signed on to bring in Lake Michigan water with Joliet, Romeoville, Shorewood, Channahon and Minooka.

The $170 million initiative was considered cost prohibitive compared with the $90 million the lake water project is expected to cost, and it was a factor in the decision even before the full extent of the pollution was known, Mayor Ray Soliman said.

In July, the City Council discussed the issue and said it had commissioned extra studies to be done on the water situation and the feasibility of several options.

The results of the studies on five of those options were presented Monday night; however, only two were recommended by engineering firm Strand Associates.

Short-term options

Plans to tap into Joliet’s water supply and purchase water from the neighboring city for the next five years; an initiative to provide point-of-use filters for residents; and a project to dig a new, deeper well and treat its water for use in place of the polluted wells were all deemed too cost prohibitive, logistically difficult or time consuming to be considered.

The remaining viable options included altering the existing wells’ pumping schedule to prioritize water from the clean wells, shutting down the heavily polluted wells, and renting and installing filtration systems on the moderately polluted wells.

The first option, which the council directed city staff to begin pursuing, involves installing a computer system that would regulate the pumping from the city’s existing clean wells and run them 24/7.

This would allow the city to get the majority of its drinking water from the wells that have not shown excessive PFAS.

Under the proposed plan, Wells 8, 11 and either 9 or 12 (which cannot run simultaneously because of their locations) would run around the clock, providing the vast majority of the cities with their required water (about 150,000 gallons per day).

At times when more water is in demand, the system would allow water to be pumped first from Well 10, then Well 7.

Strand senior associate Chris Ulm told the council that this priority order was chosen because those sites had “more available space for treatment systems and a historical record of less PFAS.”

On the occasion that more water is needed, Well 4 would be the next source drawn from.

According to the data presented by Ulm, this would be incredibly rare and may only occur on a handful of days during peak summer temperatures. It is estimated that Well 1 would never be needed under this model.

Well 1 had the highest consistent concentration of PFOAs, at two to three times the maximum limit.

The demand and controls of the pumping would be monitored and controlled by a special computer system called a Supervisory Control and Data Acquisition system, and it would require full-time employee monitoring.

Costs to the city for this plan would total about $200,000, including the installation of the SCADA system, additional water-treatment chemicals and a new employee to help monitor the system 24 hours a day. It’s expected that the system could be completely installed and implemented in six to nine months.

Although this plan would greatly reduce the amount of PFAS regularly in the city’s consumable water, 50,000 to 100,000 gallons of water from the less-polluted wells could enter the system on any given day, with most days requiring about 200,000 gallons of water in the city.

“In the summer, you’ll have to run the noncompliant wells,” Ulm said. “But the total volume going into the system will be largely reduced for the residents.”

To combat this issue, a second option was presented for use with the first, which would see the city rent filtration equipment to put on Well 10 – and potentially Well 7 – to remove PFAS from the water.

While several different filtration systems are available, the Strand team recommended that Crest Hill use granular-activated carbon filtration, which is a large-scale, more controlled version of the filters found in household Brita devices.

The filters would be implemented in large tanks at the sites of the affected wells and connected so water would move through them for 10 to 15 minutes to absorb PFAS and other contaminants before being distributed to the city.

When the filters are exhausted, the manufacturer of the tanks would replace the exhausted tank with a clean filter and take the old filter to an incineration facility. The city potentially would be renting the equipment from that manufacturer.

The spent filters are heated at 4,000 degrees, Ulm said, a process that destroys the forever chemicals but preserves 90% of the carbon filter material for reuse.

This plan potentially would cost between $1 million and $2 million per well site over the course of five years.

Before committing to the program, the city could pilot the system for a year while implementing the new pumping schedule, which seemed to gain the favor of City Engineer Ron Weideman.

“Something I want to bring up is that we all hope the Lake Michigan project makes 2030, but delays can happen, and if they do, we don’t want to be in noncompliance and be behind by a year,” Weideman said. “I think it’s worth thinking about.”

City officials are confident that if PFAS levels in the water being consumed are significantly lower by 2029, the city will be able to get an extension for full compliance with proof that the lake water plan is only a year from completion.

However, a further extension may not be permitted without penalties.

A pilot program likely would cost about $500,000 for one year.

City Administrator Blaine Wing also noted that any of the plans put into action could be partially, if not completely, funded by settlement money currently being collected by the city from 3M, DuPont and Tyco, which were deemed responsible for PFAS pollution.

The exact amount of funds expected from those settlements is not yet finalized, but about $900,000 already has been received.

City Council members, while voting to authorize city staff to implement the first option, said they would like to have more time to further consider the filtration option.

That option could lead to excess costs being paid by residents in addition to the already expected rate increases, which council member Claudia Gazal compared to “an annoying gift that keeps on giving.”

It is not clear when the City Council may revisit the issue.