Groundwater Classification Exception Area (CEA) Guidance
A Classification Exception Area or CEA serves as an institutional control by providing notice that there is ground water pollution in a localized area caused by a discharge at a contaminated site. The area and depth of ground water pollution will be determined based on actual ground water contamination, as well as fate and transport modeling. The NJDEP will establish a ground water CEA as part of a remedial action for ground water that does not meet the NJDEP ground water quality standards. One (1) down gradient sentinel well is installed to monitor the down gradient direction of the CEA extent and ensure that the plume does not move past known areas.
Obtaining a CEA involves first defining the extent of the groundwater contamination or plume. This is typically completed with a Geoprobe unit and the installation of temporary well points. The temporary wells points are followed up with permanent wells that are sampled quarterly. It should be anticipated that anticipated that a minimum of eight (8) rounds of ground water samples will need to be collected on a quarterly basis over two (2) to show continuing degradation of the ground water contaminants.
A CEA/Well Restriction Area (WRA) Fact Sheet Form is completed which will include a tabulation of the ground water data acquired from the monitoring well locations. The preparation of the CEA will include the modeling of fate and transport of Contaminants of Concern (COC) as well as the COC degradation products. Applicable maps, cross-sections and contour plans will also be produced as attachments. The CEA includes the evaluation of the current and future water use in the area as well as notification to local, county and regional health departments.
At the end of the two years and groundwater sampling data shows a degradation of compounds, a CEA can be established for the area of groundwater contamination. At this point the site would receive a conditional No Further Action (NFA) or at is is called today a Remedial Action Outcome or RAO. These determinations are conditional and become final at a future point in time where the wells are sampled and laboratory analysis shows that the contamination in the groundwater has attenuated to below regulatory levels.
Longevity: CEAs are typically of limited duration and are related to the term of a permit approval or estimated time for completion of a remediation. In some cases (e.g., sites where ground water has been contaminated by metals from historic fill or other discharges), the Department may accept a proposal for an “indeterminate” CEA longevity. If necessary, the term of a CEA also can be renewed or extended in the context of the permit or program providing regulatory oversight.
After establishing the CEA, there are Monitoring Requirements
Once a CEA has been established the RP is relived of performing active remediation as natural attenuation is the passive approach. Continued monitoring of the groundwater is required under a more relaxed schedule than the initial 8 quarterly rounds. The first three years of monitoring is different from the next five. Ultimately you will be sampling the wells until the CEA ends or applicable groundwater quality standards have been achieved.