Every person licensed as a water well driller shall write his usual signature with pen and ink in the space provided for that purpose on the license issued to him immediately upon receipt of such license. The licensee shall conspicuously display his license at his principal place of business. The person in charge of each drilling rig shall, at all times, have in his possession, when engaged in drilling, the drilling rig permit issued under the provisions of this act.
32 P.S. § 645.9