OAR 690-220-0040
Abandonment of Cased Wells
(1)
If all or a portion of the water supply well casing or the liner pipe is not removed during the abandonment of a well, the remaining casing or liner shall be thoroughly ripped or perforated. The number and size of perforations may vary, however, the perforations must be sufficient enough to allow grout to migrate outside the casing and effectively prevent the vertical movement of water. The annular space between the casing or liner and the drillhole wall shall be effectively and completely filled with cement grout applied under pressure.(2)
Perforations are not required in the sealed interval provided proof of the original seal can be verified with the original well report. The verified seal interval shall be filled with cement grout, concrete or unhydrated bentonite.(3)
Uncased portions of a cased well to be abandoned shall be filled in accordance with OAR 690-220-0030 (Permanent Abandonment) through 690-220-0050 (Abandonment of Uncased Wells).(4)
The well casing to be abandoned may be severed below land surface and removed. (See Figure 220-3.)
Source:
Rule 690-220-0040 — Abandonment of Cased Wells, https://secure.sos.state.or.us/oard/view.action?ruleNumber=690-220-0040.