Wis. Admin. Code NR § 507.13
The facility owner or operator shall inspect at least annually all monitoring devices installed for field investigations conducted under this chapter. Sampling personnel shall inspect all monitoring devices each time the device is sampled or a water level elevation is measured. If for any reason a monitoring device is damaged, provides a conduit to the subsurface or otherwise fails to function properly, the facility owner or operator shall notify the department in writing within 10 days after discovery. The device shall be repaired if possible. If the device cannot be repaired, it shall be properly abandoned and replaced within 60 days unless otherwise approved in writing by the department. Replacement and abandonment of groundwater monitoring wells shall be in accordance with ch. NR 141 and this chapter. If the device is replaced, the replacement device shall be given the same number as the device it replaced followed by the letter "R" to indicate it is a replacement, unless otherwise approved in writing by the department. An additional "R" shall be added each time the device is replaced.
Wis. Admin. Code Department of Natural Resources § NR 507.13