Description

Thomas/Wright, Inc. managed the task order and performed the field work for the collection of profile data inside a 40-inch diameter pipe. The length of the pipe is approximately 1.8 miles and measurements were taken every 20 feet.

In lieu of using traditional survey equipment in a dark, cramped, and wet environment, Thomas/Wright, Inc. suggested that the data be collected using a Geotechnical Ziplevel, a precision pressurized hydrostatic altimeter. Since the approximately distance between manholes was 1,000 feet, the ziplevel manufacturer modified its product to have a 525 foot cord.

The USACE, Portland District issued the Notice to Proceed on February 2, 2006 and the field work had to be completed before February 21, 2006, the day the water would flow in the pipe again. The project was successfully completed within the schedule.