NAPL Management

Releases of non-aqueous phase liquids (NAPL) that migrate to subsurface soil, bedrock or seep into surface water present a challenge, and we are committed to helping our clients protect the environment, eliminate potential pathways to receptors, and manage liability. Understanding the complexities and fate and transport behavior of mobile and trapped NAPL within soil-water-air interfaces in a subsurface environment allows us to assist clients in the development of appropriate LNAPL and DNAPL recovery technologies.

Over the past 35 years, Antea®Group has provided NAPL management services for oil and gas, chemical, railroad, automotive and manufacturing clients. Our NAPL solutions are risk-driven and science-based, and we have a proven track record of demonstrating the technical knowhow to assess source nature and evaluating when active remediation is necessary, establishing a remediation goal, selecting applicable remedial technology, and justifying system closure.

We have experience with a multitude of NAPL assessment and recovery technologies for both mobile and residual NAPL, whether the goal is degradation, containment, removal, or demonstrating technical impracticability. 

Legacy sites will often have NAPL in the ground for years or even decades. Legacy sites occur where remediation efforts have stalled or where a historic spill is recently discovered. Antea Group has taken on legacy sites where other consultants have struggled to make progress toward closure. We apply technologies and remediation strategies depending on the type and age of the release, the stage of investigations, and the type of previous remedial attempts.

Services also include assessing the nature and extent of the NAPL, dissolved phase migration pathways, and potential receptors using existing or new data for the development of a conceptual site model (CSM). Development of the CSM allows us to focus on the source and effectively remediate to risk based or state or federal established regulatory standards. 

Emergency response refers to a recent spill of a liquid chemical or mixture of chemicals. In these cases, public safety and recovery are the first priority. If a majority of the NAPL is recovered quickly before saturating the ground or entering drains or ditches to a wetland or water body, the long term remediation costs are much lower. However, when a release of NAPL goes undetected, the NAPL can travel great distances in the subsurface spreading and smearing in the groundwater capillary zone until equilibrium is reached, resulting in a more difficult and costly recovery.