On December 3rd, NJDEP issued version 1.0 of its Technical Impracticability Guidance for Groundwater. Technical Impracticability (TI) is defined by NJDEP as “a condition where remediation of groundwater to the applicable standards is not feasible from an engineering perspective because of the limitations in the currently available groundwater remediation system engineering methods or technologies at the time the remedy is being designed.” A TI determination can be applied to an entire site or an area of concern (AOC).
The guidance document provides several examples of when a TI determination may be appropriate, including hydrogeologic conditions (such as fractured bedrock), contaminant conditions (such as dense non-aqueous phase liquids [DNAPL]), and remedial technology limitations. The guidance states that “TI is usually evaluated after an effort to deploy the currently available technology has been attempted, evaluated, optimized, and then reevaluated,” and adds that making a TI determination “prior to deployment of a technological solution is exceptional.” Cost can be a factor in the evaluation of a remedy for TI, but it should be a supplemental consideration.
It should be noted that when a TI determination is utilized, a classification exception area (CEA) and a ground water remedial action permit are still required, along with ongoing monitoring and biennial certifications, in accordance with the ARRCS rules at N.J.A.C. 7:26C-7. In addition, the NJDEP reserves the right to rescind or modify the TI determination and require further remediation if and when future advances in remedial technologies render the TI inapplicable. The guidance notes that the evaluation of a TI should be viewed as a collaborative process with the NJDEP.
The Technical Impracticability Guidance for Groundwater is posted on NJDEP’s Guidance Library at:
Tim Dempsey, PG