ON-THE-GROUND VALIDATION

The hydrologic findings of the PHC and CHIA are based on predicted changes to the hydrologic balance. The changes are estimated from information on baseline conditions, mining plans, mitigative measures, and the use of specific analytical techniques such as hydrologic simulation models. Because they are based on predictions, the only way to validate the hydrologic findings associated with a particular permit application is to scrutinize ground water and surface water monitoring reports during the mining and reclamation phases through final bond release. Thus, monitoring data provide the unique opportunity for validating hydrologic findings and increasing the confidence in the predictive tools used. The uses of monitoring data for validating hydrologic findings and for other related purposes are summarized below:

Evaluation of the PHC and CHIA:

These hydrologic impact analyses provide estimates of the residual, unmitigated impacts after application of all mitigation measures defined in the hydrologic reclamation plan. As such, monitoring provides a means of evaluating actual changes associated with the operation. Monitoring results provide valuable feedback for the applicant to validate the PHC predictions, and for the RA to validate the predictions and the techniques associated with the CHIA. Inherent in this evaluation is a determination of effectiveness of the mitigation measures used.

Emerging Problem Indication:

An applicant's monitoring data is not only necessary for assessing compliance with the regulatory requirements, but also provides a useful opportunity for tracking trends that may give rise to problems. This is especially important for determining whether or not a water supply may be affected, thus allowing early detection and mitigation before damage occurs.

Supplemental Information:

Monitoring data can be used as supplemental information for permit revisions, permit renewals and new permit applications. Expanded data bases for an area should result in reduced data collection costs and improved accuracy of PHC's and CHIA's.

Bond Release:

Hydrologic monitoring data are useful in reviewing the moderate to long-term impacts of the operation upon the water resources in the permit and adjacent areas. Such a review provides an additional valuable tool to the RA in making bond release decisions and in substantiating the basis of such decisions.