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

   1. (1) D5299/D5299M-18 (2018): Standard Guide for Decommissioning of Groundwater Wells, Vadose Zone Monitoring Devices, Boreholes, and Other Devices for Environmental Activities;
   2. (2) D5092/D5092M-16 (2024): Standard Practice for Design and Installation of Groundwater Monitoring Wells;
   3. (3) D5521/D5521M-18 (2025): Standard Guide for Development of Groundwater Monitoring Wells in Granular Aquifers;
   4. (4) D5978/D5978M-16 (2024): Standard Guide for Maintenance and Rehabilitation of Groundwater Monitoring Wells;
   5. (5) D6724/D6724M-16 (2024)e1: Standard Guide for Installation of Direct Push Groundwater Monitoring Wells;
   6. (6) D6725/D6725M-16 (2024)e1: Standard Practice for Direct Push Installation of Prepacked Screen Monitoring Wells in Unconsolidated Aquifers.

2. (b) Each monitoring well shall be:

   1. (1) Constructed, maintained, and decommissioned only by a New Hampshire-licensed water well contractor holding a valid technical drillers license under RSA 482-B;
   2. (2) Developed prior to sampling; and
   3. (3) Allowed to equilibrate a minimum of 2 weeks following installation prior to sampling.

Source. (See Revision Note at chapter heading for Env-Or 600) #8812, eff 2-1-07; ss by #10831, eff 6-1-15; ss by #14419, eff 11-4-25, EXPIRES: 11-4-35