1. (a) Monitor well construction.

   1. (1) Monitor wells shall be constructed of materials which:

      1. (A) Are resistant to chemical and physical degradation;
      2. (B) Will not interfere with ground water quality; and
      3. (C) Meet the requirements of Section 5.7 of Solid Waste Disposal Facility Criteria, Technical Manual, EPA 530-R-93-017, November, 1993, or ASTM D-5092-90, Standard Practice for Design and Installation of Ground Water Monitoring Wells in Aquifers.
   2. (2) Alternate methods of well construction, installation, or development must be specifically approved by the Division of Solid Waste Management.
   3. (3) Following construction, each well shall be developed to the degree necessary to restore formation hydraulic conductivity and ensure low turbidity samples which are representative of formation ground water quality.
   4. (4) Prior to sampling, turbidity values shall be allowed to stabilize to a level which is representative of ambient water quality in the formation.

   5. (5) If during background or routine sampling, the turbidity values consistently remain above ten (10) NTUs, a qualified ground water scientist shall:

      1. (A) Evaluate the integrity of the well;
      2. (B) Redevelop the well if necessary; and/or
      3. (C) Provide written justification that the turbidity values present in the samples are representative of ambient water quality in the formation.
   6. (6) If the justification provided by the permittee for the observed turbidity values is not considered valid, and/or if the well cannot be effectively redeveloped to reduce turbidity values below ten (10) NTUs, and/or if the well is found to be unreliable for generating representative water quality samples, it must be replaced prior to the next scheduled sampling event.
2. (b) Installer licensing and supervision. Well installers must be licensed by the State of Arkansas and the installation crew must be supervised in the field by a geologist or engineer experienced in the installation, construction, and development of monitoring wells.

3. (c) Well casings.

   1. (1) Monitoring wells must be cased in a manner that maintains the integrity of the monitoring well bore hole.
   2. (2) This casing must be screened or perforated and packed with gravel or sand, where necessary, to enable collection of ground water samples.
   3. (3) The annular space (i.e., the space between the bore hole and well casing) above the sampling depth must be sealed to prevent contamination of samples and the ground water.
   4. (4) Completed well casings should extend approximately three feet (3’) above natural grade and must have an anodized aluminum or rust-proof external protective casing with a locking lid.
4. (d) Well numbering. Each completed well must be designated with a unique alphanumeric label which must be clearly fixed to the outside of the well casing.
5. (e) Protection posts. Wells which could possibly be damaged by equipment or vehicular traffic must be protected by steel post.

6. (f) Division of Environmental Quality approval.

   1. (1) No monitor well or piezometer shall be installed, decommissioned, replaced, repaired, or otherwise altered without prior approval by the Division of Solid Waste Management.
   2. (2) Upon completion of a well installation, replacement, decommissioning, repair, or alteration, a report shall be made to the Division of Solid Waste Management and a copy placed in the facility operating record.
   3. (3) The work quality and methods must be certified by the supervising professional.

7. (g) Monitoring well survey.

   1. (1) Each completed monitoring well must be surveyed following the guidelines under 8 CAR § 60-426.
   2. (2) Additional to those guidelines, the survey should establish the elevation (referenced to mean sea level) of the ground surface and the top of the casing for each well location.

Codification Notes: “NTU” means Nephelometric Turbidity Unit.