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• If the casing-riser cap is missing, replace it. If the well is not a flush-mount well and the <br /> casing riser does not have a small hole drilled just below the cap, the riser cap should not be <br /> installed in an air-tight manner. If the well is a flush-mount well, the riser cap should be a <br /> water-tight cap. The water-tight cap should be installed securely in the well to prevent <br /> liquids that collect in the vault from entering the well casing. Flush-mount wells with vaults <br /> that permit drainage from the vault or those with water-tight vault lids do not need water- <br /> tight riser caps. <br /> • If the casing riser is damaged to the extent that standing liquids inside the security casing <br /> can enter the well, the damaged section should be cut off below the point of breakage and <br /> a new section of riser installed. The new riser should have a weep hole drilled in it just <br /> below the cap to allow air pressure equilibration within the well bore. Care should be taken <br /> to ensure that the new casing riser is fitted with a casing-riser cap. This corrective action <br /> should be noted on the checklist and the well should be scheduled for a new elevation <br /> survey. <br /> • If the well is not numbered or marked with a well identification label, or if the number on <br /> the well does not match the well location map, a correct well identification number must be <br /> marked on the well. First, the correct well identification must be conclusively determined. <br /> This can be done by consulting the well location map (if it has been certified to be correct), <br /> consulting original field logs and completion records relating to the well's installation, and <br /> consulting logs from other previous field activities such as sampling, episodes, and water- <br /> level measurements. Project personnel may also be interviewed in an effort to establish <br /> well identification. Once the identity of the well has been conclusively established, the well <br /> should be labeled with this number using a permanent method. Stamping the well <br /> identifier into the steel security casing with a steel stamp is recommended. The identifier <br /> should be stamped in the lid on the security casing and on the security casing itself, just <br /> below the lock. The identifier should also be written on the bottom side of the security <br /> casing lid using a permanent ink pen. Multiple-completion wells should have the top of <br /> each riser cap marked with a letter designating the completion, such as "U" and "L" for <br /> "upper" and "lower." The casing risers in a multiple-completion well should then be <br /> marked in a similar manner. Take care to ensure that the label on the casing riser is below <br /> the position occupied by the cap or the weep hole, if present. <br /> B.15.6. Redevelopment Procedures <br /> Monitoring wells shall be redeveloped if the well inspection procedure indicates that excessive <br /> sedimentation is occurring, if the capacity of the well appears to have significantly declined <br /> during the course of a sampling program, if there is evidence of screen encrustation or clogging <br /> by iron bacteria, or if the well is simply scheduled for regular redevelopment. <br /> • Possible redevelopment techniques include compressed-nitrogen jetting and air-lift <br /> pumping, surge blocking and pumping or bailing, suction-lift pumping, submersible <br /> pumping, and foot valve pumping. <br /> Daub &Associates, Inc. Page B-37 Natural Soda LLC 2022 SAP <br />