Safe Digging: Sticky Tolerance Zones

Sometimes tolerance zones can be tricky. In the example below a hospital is adding a drop-off area to the front of the building (indicated by the purple box). It is located in a major intersection with many underground facilities.

tz1.gif

 Here, the facility locators have marked the communications and electric lines. The gray area represents your work site, which you have white lined. What you notice is the communications (orange) line runs through your work site and the electric line is outside your worksite. 

Here, the facility locators have marked the communications and electric lines. The gray area represents your work site, which you have white lined. What you notice is the communications (orange) line runs through your work site and the electric line is outside your worksite. 


 The entire tolerance zone for the communications line is within your work site. Remember, the tolerance zone is 24 inches on either side of the underground facility. Because the electric line is outside your work site, can you assume that beyond the communications line you can dig freely?

The entire tolerance zone for the communications line is within your work site. Remember, the tolerance zone is 24 inches on either side of the underground facility. Because the electric line is outside your work site, can you assume that beyond the communications line you can dig freely?


 NO! When you figure the tolerance zone for the electric line, you see that it runs within your work site. If you dig beyond the communication's tolerance zone without first verifying where the electric line runs, you run the risk of damaging the electric line.

NO! When you figure the tolerance zone for the electric line, you see that it runs within your work site. If you dig beyond the communication's tolerance zone without first verifying where the electric line runs, you run the risk of damaging the electric line.