Remote Water Level Monitoring During Sinkhole Repair

Construction monitoring case study.

Crumbling interceptor line causes massive sinkholes in Fraser, MI.

What happens when a huge sewer line collapses on Christmas Eve, causing a sinkhole the size of a football field that destroys three homes, causes 22 more to be evacuated, and costs over $70MM to repair? In Sterling Heights, MI, a critical infrastructure rehabilitation project has been underway since 2016 to prevent this disaster from ever happening again. Involving 29 miles of interceptor lines supporting over 600,000 people, this multi-year project required the construction of the “Segment 5” pump station with a massive earth retention system and a 65-foot deep shaft to expose the aging interceptor and effect repairs.

FK Engineering was retained to provide geotechnical monitoring during excavation and construction. Conditions were challenging: sand, silt, and a high water table required continual de-watering of the site, making 24/7 remote water-level monitoring critical to the project.

“We’re lowering the water level to 75 feet, below our excavation level … we needed to keep an eye on it 24/7 because we need to know if our pumps are down or not working as efficiently as they should,” Zachary Carr, VP of FK Engineering, explained.

GeoNet Integration into Inzwa’s Cloud Platform for Environmental Monitoring

Zachary Carr with FK Engineering placed ten GEOKON GeoNet vibrating wire piezometers connected to data loggers on the site to provide continual remote water-level monitoring. In addition to the original third-party environmental monitoring software, he also opted to add the Inzwa Cloud environmental monitoring system as a backup, given the platform’s ability to log, visualize and report data from third-party devices, including GeoNet data loggers. “We needed to make sure that if there were problems on the weekends – because that tends to be when we have problems – that we’re alerted right away with their emergency alerts,” Carr explained.

Inzwa Cloud’s Performance and Reliability

“So, of course it was a Saturday morning when the [original] remote system went down,” Carr continued. “We were all kind of panicking, and then it hit me, let’s check the Inzwa platform as well… I was able to still see our data, which was a complete and utter relief to me,” he said. With the Inzwa Cloud, Carr was able to confirm that the devices were operational and that no crisis was developing. “With the criticality of monitoring water levels 24/7, Inzwa saved my bacon and reduced my stress level that weekend,” he concluded with a smile.

"With the criticality of monitoring water levels 24/7, Inzwa saved my bacon and reduced my stress level that weekend."
- Zachary Carr
FK Engineering

GEOKON and FK Engineering Joint Webinar