ON OUR SHOULDERS
3.27.15
On our Shoulders by Robert Dufresne
Municipal engineering projects rarely start on a clean sheet of paper. Chances are the project site was long ago disturbed by previous projects now bypassed by time and technology. In New England, the water distribution systems and wastewater collection systems were built over the past century and a half and many of these pipes are still in use. Rarely is a water or wastewater treatment facility constructed from scratch, usually these old facilities are expanded or upgraded to meet the challenges of today. In order to efficiently mesh new improvements with older facilities, it is crucial to ascertain the location and condition of these existing systems. Since water and wastewater infrastructure is primarily underground, it is crucial that “as-built” or record drawing information is both available and accurate.
In my experience, even with the universal use of highly accurate global positioning system (GPS) mapping techniques, record drawing information has deteriorated in its availability and accuracy. Even in the municipal sector, some project officials drop record drawings as a project element due to budget constraints or view the need to complete record drawings as a “regulatory requirement”. Worse, some engineering firms take no role in the completion of record drawings and require the contractor to complete this invaluable service. The condition and accuracy of these contractor prepared drawings are typically first assessed in an emergency situation and the results are rarely satisfactory.
I had an occasion to search archived drawing files and reviewed blueprints (actual blue prints!) for a water transmission main project completed in 1933 by Barker & Wheeler, Inc. Many towns and villages in New England used this engineering company to complete engineering projects from 1900 to around 1940. The drawings were prepared, by hand, with the skill and discipline that engineers strive for today. The pipe and valve material and pressure class was carefully noted and ties from buildings and geographic features were shown in detail. All elevation references were shown to the tenth of a foot based on the “chiseled square on the front steps of the court house”. The quality of these documents prepared almost a century ago allow today’s engineers to assess pipe rehabilitation techniques as a cost savings measure and allows us to stand on the shoulders of those that came before us.
The underground improvements installed today will provide service for the next 100 years. How will we pass this critical information onto the next generation? Will these future engineers be impressed with the record keeping and pride we took in recording this information? Will they be able to stand on our shoulders?
