On February 12, 2002, at the construction site for the Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory, a backhoe operator struck and severed a buried 240-volt temporary power cable with his backhoe bucket.

This tripped a circuit breaker and the operator was not injured. The contractor reported this as a near miss. The buried cable supplied electrical power for the construction of the SNS Front End Building, and was included in surveys for buried electrical lines. This temporary power line was noted in the original excavation permit, and was marked at the construction site for information. However, since the cable lay outside the area being excavated, no particular care was taken to preserve its markings, and the markings were substantially obliterated during the excavation.

As the excavation progressed, the height of the earthen mound forming around the excavation became a safety concern, and the excavation crew decided to slope the wall. This sloping activity entailed digging beyond the area originally planned, and into the location where the temporary power line was buried.

The investigation of this occurrence is still ongoing, and there are no formal causal analyses or lessons learned at this time. However, it appears clear at this point that the excavation permit should have been amended to address the new area being dug. If done correctly, the amendment process would have identified the buried electrical line from the previous surveys.

On January 30, 2002, a similar event involving a backhoe severing a 480-volt buried line occurred near Buildings 52 and 58 at the Thomas Jefferson National Accelerator Facility. The site utility drawing incorrectly indicated that there were no electrical lines in the vicinity.

On February 18, 2002, a contractor cut through a 110-volt conduit with his concrete-cutting saw while installing a shower drain line at the Argonne National Laboratory. As-built drawings were inaccurate, and there had been no instrument surveys for embedded conduits.  There were no injuries in either occurrence.