Remedial Design

AquAeTer performed a feasibility study to evaluate options for neutralization of acidic groundwater at a former manufacturing site. Our study included evaluation of a traditional limestone barrier wall and our proposal of an innovative liquid alkaline injection system. This study resulted in AquAeTer recommending a sodium bicarbonate injection, which was subsequently approved by the state. Our team designed a simple, low-cost injection system for use in a pilot study. The system relies on gravity to feed the solution, and requires no moving parts or electricity.

Within two weeks of commencing the injection, pH levels in down-gradient wells increased. Results of the next year indicate successful neutralization of groundwater (pH > 7 S.U.) and the ability of the bicarbonate solution to travel through the aquifer. Once the pilot area was successfully neutralized, the injection locations were moved to other target areas on-site. Since the remediation system has been in place, none of the neutralized wells have shown any indications of acid rebound.

AquAeTer provided the following services to its client for this sampling and reporting project:

  • Design of a low capital cost injection system
  • design and implementation of pilot study
  • Oversight of installation of the system
  • Oversight of field data collection activities
  • Evaluation of field data collected during the pilot study
  • Preparation of a summary memo with results of the pilot study for presentation to the State