October 2018 Update on GAC Filters

The Township completed installation of the final two water filters on Oct. 1, 2018, bringing the total to five granular activated carbon, or GAC, filters to remove PFAS from the municipal water supply.

Last week, seven truckloads of spent sand and anthracite were removed from the filters and replaced with the GAC best able to remove PFAS. This is a continuation of the pilot project using the $750,000 grant from the Michigan Department of Environmental Quality.

As of the October 25, 2018 press release, all water is now 100% free of PFOS and PFOA from our water supply:   Plainfield Township Press Release

September 2018 Update on GAC Filters

Test results for municipal drinking water being treated with the new granular activated carbon filters have remained non-detect for PFOS and PFOA during the summer months.

Despite our hot, late summer, which has increased demand for water, the three new GAC filters have performed as expected. As demand begins to taper off in September, our Water Department is making plans to begin installation of the final two GAC filters.

Installation is expected to begin the first week of October and should take approximately three weeks. After raising the arms in the two filter beds, the Township will remove the old filtration material and replace it with granular activated carbon, which has demonstrated its ability to remove PFOS and PFOA. After additional testing, the new GAC filters should be brought online in the third week of October.

“Because of the high demand for water in July and August, we could not afford the downtime to replace the final two filters,” explained Rick Solle, director of public services. “We had to wait until customer demand goes down, which typically happens at the end of summer when folks stop watering their lawns.

“Once the final GAC filters are installed, we will have the capacity to filter 9 million gallons a day through GAC, which is enough water to take care of regular demand.”

June 2018 Update on Granular Activated Carbon Filter Installation from Plainfield Township

The first two filter beds were successfully replaced with granular activated carbon (GAC) last week (6-4-2018), and the Township is currently waiting on test results to determine their effectiveness at reducing the trace amounts of PFAS in the water system. As additional filters are changed out in the coming weeks, the PFAS levels will continue to drop in the system. We expect all the filters will be installed by the end of summer.

Work began at the Plainfield Water Department Treatment Plant on 6-1-2018 to replace the existing sand and coal filter media with granular activated carbon (GAC). The first two filters have been changed out and, after testing is complete, they will be brought online later this week. This will begin to reduce the trace amounts of PFAS present in the water system.  A video showing the installation process for the filters is available here.

Throughout the process, each phase is carefully tested to prove the effectiveness in removing contaminants. Installation and testing is expected to be finalized by the end of summer. The old filtration materials, which consisted of sand and anthracite coal, are considered non-hazardous and will be taken to a landfill in Ohio to be disposed of.

Update on Federal Lawsuit

MDEQ, Wolverine World Wide and Plainfield Township representatives are meeting on Thursday, June 7 to discuss the areas where municipal water could be expanded in 2019 to address the water concerns. Additionally, the meeting will cover how expanding the municipal water system to those affected areas can be included in the decree that is being developed in the federal lawsuit.

The Township’s engineers continue their design and cost estimate work. Additionally, the Township’s attorney continues to advocate for a prompt extension of municipal water in PFAS affected areas of the Township as the most effective long-term potable water solution.

The 2017 Plainfield Township water quality report including an explanation for the violation of TTHM (trihalomethanes) levels can be found here: 2017_water_quality_report

May 2018 Test Results from the New GAC Filter

Initial test results after the installation of the new granular activated carbon, or GAC, filters show PFAS levels in the municipal water that run through the GAC filters have been reduced to non-detect.

Utilizing the two new GAC filters along with two of the existing filters, the total PFOS in the water leaving the plant for the system is currently reduced to 2.1 ppt. The PFOA level in the same water is currently non-detect. We will regularly monitor the PFAS levels to assess the continued effectiveness of the new GAC filters.

Until the additional GAC filters are completed, PFAS levels may fluctuate during the peak demand time in the summer. However, even then, Plainfield municipal water should contain less trace PFAS than municipal systems using surface water sources.

Additional in-house testing on the new filters have all been negative for the presence of bacteria. Total organic carbon, or TOC, is also significantly lower, which in turn lowers disinfection by-products such as trihalomethanes, or THMs.

With positive test results on the first filters, we plan to move forward with replacing another filter with GAC. Work will begin after the July 4^th holiday, with the GAC installation planned for the week after the holiday.