The CCR Rule requires that the owner or operator of a CCR unit must measure total recoverable metals concentrations without field filtering of the samples. The CCR Rule was developed with the assumption that monitoring wells will be designed and installed in such a manner so that turbidity of less than 5 Nephelometric Turbidity Units (NTUs) can be achieved without filed filtering.
Several of the CCR units for which AGES designed CCR groundwater monitoring networks had existing wells and piezometers already in place. In most cases, these wells and piezometers were designed to be sampled and field filtered or were not intended to be sampled at all. AGES conducted preliminary sampling of these existing wells under attorney-client privilege using the same sampling procedures to be used for the CCR program. This was done to evaluate if it would be possible to obtain turbidities less than 5 NTUs from these existing wells and to get an idea of what the analytical results would be if the existing wells were used. The goal of the preliminary sampling was to determine if any of the existing wells and piezometers would be suitable for use in the CCR program. Other valuable information was also obtained during the preliminary sampling events that was used in the design of the groundwater monitoring network.