Dewatering Former Wastewater Lagoons on the Lake Huron Shoreline

SF-484 sand and mixed media filters

BF-6 bag filter housing skid

LPV-7000 and LPV-5000 GAC vessels

Floating intake

Remote telemetry monitoring system

Automated pump controls

Demolition is underway at a former manufacturing site on the Lake Huron shoreline in Alpena, Michigan, and the land cannot be backfilled until its wastewater lagoons are emptied. Global is dewatering two lagoons holding roughly 30 million gallons of water.

The water runs first through SF-484 sand filters and BF-6 bag filters to reduce suspended solids, then through LPV-7000 and LPV-5000 GAC vessels to reduce PFAS, specifically PFOA. The system can handle up to 500 gallons per minute and typically runs at 250 to 400, returning treated water to the lake through a regulated NPDES outfall.

The lagoon intake floats, drawing water from above the sediment layer to extend bag filter life. Floating barriers in front of the intake reduce the impact of recurring algae blooms on the sand and bag filters. Bag filters are changed every one to three days, and daily when pumping nears the lagoon bottom.

Global’s remote telemetry monitoring system and automated pump controls keep the system running continuously without a Global operator on site, and the telemetry logs the flow and volume data the NPDES permit requires. Global trained the contractor’s on-site staff on basic maintenance and sends them alerts when something needs attention. Weekly and on-call field service visits through the end of 2026 cover NPDES compliance sampling, system readings, backwashing, lagoon depth surveys, and equipment fueling. Between visits, Global tracks intermediate sample results and changes out carbon as needed to maintain permit compliance.

Once dewatering is complete, the site can be backfilled and prepared for redevelopment.