Cleaning Contaminated Groundwater in Place

An innovative system optimises treatment by drawing water from the aquifer and adding lactate at an onsite treatment plant.

After acquiring the former industrial site and discovering it highly cont­a­m­i­nated with volatile organic compounds (VOCs), Rockwell Automation struggled to find a sustainable, effective remedy. After years of exhaustive efforts, the automation controls company partnered with CDM Smith and finally discovered a way to remediate chlorinated solvents in the shallow groundwater. Our solution: enhanced anaerobic biore­me­di­a­tion, which leverages naturally occurring bacteria, boosted by simple lactate, to cleanse the cont­a­m­i­nated groundwater in place.

The complex and innovative system optimises treatment by drawing water from the aquifer and adding lactate at an onsite treatment plant. The lactate-enhanced water is then re-injected into groundwater target zones where it expedites the dechlo­ri­na­tion process, aiding bacteria - Dehalo­coc­coides spp. - in breaking down solvents into harmless byproducts. An innovative well system - comprising horizontal recovery and vertical injection wells - continually recir­cu­lates groundwater to ensure that lactate, bacteria and cont­a­m­i­nants are in constant contact, creating an unpar­al­leled environment for decon­t­a­m­i­na­tion.

At startup, the highest concentration area had more than 2,000,000 parts per billion of methylene chloride. Within the first 6 months of operation, VOC mass was reduced by more than 90 %, and after 6 months, the methylene chloride had been completely remediated and has not been observed since. Destroying the contaminants in the ground mitigates risks such as accidental release, protecting workers and the environment.