A crack in this new gasket would have allowed a slow leak in the line to erode the earth around it enough to cause the recent sinkhole in White Rock. Courtesy/LAC

COUNTY News:

A new, but faulty, gasket appears to be the cause of the sinkhole that recently appeared on the road near the intersection of N.M. 4 and Rover Boulevard in White Rock.

The water transmission line feeding White Rock and running parallel to N.M. 4 was replaced earlier this year under a Los Alamos Department of Public Utilities (DPU) project. Contractor Wagner Construction led the effort, which included a section of pipe that crossed under the roadway in White Rock. Shortly after the project was completed, a sinkhole began to appear under the far-right eastbound lane of N.M. 4 as it approaches the intersection at Rover Boulevard.

Personnel from DPU and the New Mexico Department of Transportation coordinated repair efforts as representatives from Wagner Construction, which is based in Minnesota, returned to Los Alamos in response to news of the sinkhole last week.

The faulty gasket was installed at a joint that enabled the pipeline to cross under the road. It passed a pressure test when it was installed, however a crack was discovered on the gasket when Wagner worked to repair the sinkhole. This crack would have allowed a slow leak in the line to erode the earth around it enough to cause the sinkhole.

Wagner has repaired the pipeline infrastructure. Repairs to the road above it are in the works. Motorists on N.M. 4 can expect the right turn lane on N.M. 4 to remain closed until the road work is complete, which should occur sometime this week through May 16.