Laserfiche WebLink
the movement of poor-quality water,pollutants,or contaminants through <br /> the destroyed well structure. <br /> Material to be extracted from the original borehole shall be removed by <br /> means of drilling, including overdrilling, if necessary. The enforcing agency <br /> should be contacted to determine requirements for proper disposal of <br /> removed materials. <br /> Casing, filter pack, and annular seal materials may be left in place during <br /> sealing operations, if the enforcing agency agrees they cannot or should not <br /> be removed. In such a case, appropriate sealing material shall be placed in <br /> the well casing, filter pack, and all other significant voids within the entire <br /> well boring. Casing left in place may require perforation or puncturing to <br /> allow proper placement of sealing materials. Sealing material may have to be <br /> applied under pressure to ensure its proper distribution. <br /> C. Monitoring wells shall, at a minimum, be destroyed in accordance with the <br /> requirements of Section 23 of the Water Well Standards if located in an area <br /> free of any known or potential contamination or pollution. <br /> B. Exploratory Boris. Exploratory borings shall be completely filled with appropriate sealing <br /> material from bottom to top, if located in areas of known or suspected contamination or <br /> pollution. Borings located outside such areas shall, at a minimum, be filled with sealing <br /> material from ground surface to the minimum depths specified in Section 23 of the Water Well <br /> Standards. Additional sealing material shall be placed below the minimum surface seal where <br /> needed to prevent the interchange of poor-quality water,pollutants,or contaminants between <br /> strata penetrated by the boring. <br /> Appropriate fill or sealing material shall be placed below and between intervals containing <br /> sealing material. Sealing material is often economical to use as fill material. <br /> The boring shall be inspected immediately prior to filling and sealing operations. All <br /> obstructions and pollutants and contaminants that could interfere with filling and sealing <br /> operations shall be removed prior to filling and sealing. The enforcing agency shall be notified <br /> as soon as possible if pollutants or contaminants are known or suspected to be in a boring to <br /> be destroyed. Well destruction operations may then proceed only at the approval of the <br /> enforcing agency. The enforcing agency should be contacted to determine requirements for <br /> proper disposal of removed materials. <br /> C. Placement of Material. The placement of sealing material for monitoring wells and exploratory <br /> borings is generally described in Section 23 and Appendix B of the Water Well Standards. The <br /> following additional requirements shall be observed when placing sealing material for <br /> monitoring well or exploratory boring destruction. <br /> 1. Placement Method. The well or exploratory boring shall be filled with appropriate <br /> sealing,and fill material where allowed,using a tremie pipe or equivalent,proceeding <br /> upward from the bottom of the well or boring. <br /> Sealing material shall be placed by methods (such as the use of a tremie pipe or <br /> equivalent) that prevent freefall, bridging, and dilution of sealing materials, and/or <br /> prevent separation of aggregate from sealants. Sealing material may be placed by <br /> -52- <br />