PURPOSE: This rule ensures the method of drilling utilized allows a representative sample to be taken of the zone to be monitored and ensures the appropriate zone is being monitored.

1. (1) There are many different drilling technologies available for permitted monitoring well drillers to utilize. The method of drilling chosen must not add contaminants to the well which would adversely affect the purpose of the well. Certain types of drilling methods can mask or hide the contaminants which are being monitored for or may not allow for collection of adequate geologic data to properly understand contaminant movement.

AUTHORITY: sections 256.606 and 256.626, RSMo (Cum. Supp. 1991).* Original rule filed Aug. 17, 1993, effective March 10, 1994. Amended: Filed July 13, 1994, effective Jan. 29, 1995. *Original authority: 256.606, RSMo (1991) and 256.626, RSMo (1985), amended 1991.