1. (a) Monitoring wells shall be designed, installed, developed, maintained, and decommissioned in accordance with We 100-1000 and the practices described in:

   1. (1) “Standard Practice for Design and Installation of Groundwater Monitoring Wells", document identification number ASTM D5092/D5092M-16, dated 2024, available as noted in Appendix B;
   2. (2) “Standard Practice for Direct Push Installation of Prepacked Screen Monitoring Wells in Unconsolidated Aquifers", document identification number ASTM D6725/D6725M-16, dated2024e1, available as noted in Appendix B;
   3. (3) “Standard Guide for Installation of Direct Push Groundwater Monitoring Wells", document identification number ASTM D6724/D6724M-16, dated 2024 e1, available as noted in Appendix B;
   4. (4) “Standard Guide for Maintenance and Rehabilitation of Groundwater Monitoring Wells", document identification number ASTM D5978/D5978M-16, dated 2024, available as noted in Appendix B;
   5. (5) “Standard Guide for Development of Groundwater Monitoring Wells in Granular Aquifers", document identification number ASTM D5521/D5521M-18, dated 2025, available as noted in Appendix B; and
   6. (6) “Standard Guide for Decommissioning of Groundwater Wells, Vadose Zone Monitoring Devices, Boreholes, and Other Devices for Environmental Activities", document identification number ASTM D5299/D5299M-18, dated 2018, available as noted in Appendix B.
2. (b) Monitoring wells shall be constructed, maintained, and decommissioned only by a licensed New Hampshire water well contractor holding a valid technical drillers license under RSA 482-B.

3. (c) Monitoring wells shall be:

   1. (1) Developed prior to sampling; and
   2. (2) Allowed to equilibrate a minimum of 2 weeks following installation prior to sampling.

Source. #8812, eff 2-1-07; ss by #10832, eff 6-1-15; ss by #14420, eff 11-4-25, EXPIRES: 11-4-35