Utilities project preserves trees, improves sustainability| January 26, 2011
As anyone who has ever participated in a remodeling project can attest, replacing and updating utilities is never an easy prospect. The project becomes even more daunting when, instead of a single family residence, the utilities for an entire college campus are updated -- especially when that campus happens to be almost 318 years old.
William & Mary’s ancient campus, besides being steeped in the history of our country’s earliest days, is extremely beautiful. Nowhere on campus is this more apparent than the Sunken Garden and the Wren Building, both of which are framed by majestic trees-the very trees which would be threatened by the Historic Campus Utility Project if the new piping was trenched in the existing steam tunnel path.
The standard procedure for installing underground piping is to dig a large trench, lay the pipes in, and then cover them. In this case, the trench would have to be 20 feet wide and would have passed behind the Wren Building, between Tucker and Ewell Halls -- a path which would have jeopardized the 70-year-old beech trees that shade the sidewalks in front of the Wren.
“The project team did not like this option and knew that it wouldn’t be popular with the student body, faculty, staff or alumni, so we came up with a solution,” said Project Manager Mark Ballman.
To save the trees and allow the utility project to proceed, Ballman said, they decided to dig 20 feet down beside Tucker Hall and Ewell Hall and then bore horizontally into the earth, pushing 8-foot sections of 4-foot diameter concrete casing as they went to form a conduit for the pipe to connect the Campus north and south of the Sunken Garden. Since the roots of the beech trees only go down about three feet below the surface, the concrete casing is well below the roots and will not harm the trees, Ballman said.
Only three or four large trees have been removed or been marked for removal in the course of the project, which began in May 2010 and is slated to end in the summer of 2012. The trees that have been removed were magnolias.
Sometimes trees have to be trimmed in the course of the project, to make room for the construction equipment. When this is necessary, Facilities Management consults with or brings in the College’s arborist to trim the trees correctly, Ballman said. They use fertilizer to strengthen the trees before trimming and to provide physical protection for the roots before using large vehicles that compact the soil and could crush the roots, he added. According to Ballman, the College has paid a slight premium, but it is a necessary step to preserve the trees and visual appeal of the College. Dan Patterson, the associate director for utilities in Facilities Management, said that project team also moved the location of a manhole to preserve an elm tree that was significant to the campus.
In addition to sparing the trees, the project team worked around other important features of campus, including archaeologically sensitive areas, historic sites, handicap accesses, city sidewalks and roads, and campus buildings. According to Ballman, the project team worked closely with others at the College, including the William & Mary Center for Archaeological Research (WMCAR), from day one of the project. Referring to the placement of the underground pipes, Ballman said he asks himself, “We need to get here, so how do we do that without disturbing various important areas of campus?”
“It’s like a giant game of Twister,” he said.
Before the construction crew moves into any project area, it is surveyed by WMCAR archaeologists using standardized survey methods to assess the nature and distribution of any potentially significant archaeological deposits, according to Joe Jones, the Director of WMCAR. For example, archaeological survey of one project area last summer led to the identification of two unmarked graves dating to the early historic period. Due to their age and poor preservation, the graves, which were found under the east end of James Blair Drive between the King and Queen Gate and the rear of Tucker Hall, contained almost no interpretable evidence other than tiny bone fragments. The remains were initially believed to be infants, based on the fact that the size, shape, and orientation of the graves closely resembled human burials of the period, though subsequent excavation, recovery and close inspection of the interred remains revealed they were bone fragments from two dogs that were apparently and uncharacteristically buried in formal grave shafts on the College campus sometime prior to the mid-18th century.
In addition to these discoveries, archaeological survey in other project areas on campus has led to identification of interesting and significant historic resources such as a colonial-period trash pit behind Tucker Hall that is a virtual time capsule of artifacts and deposits dating to just before the Revolutionary War, archaeological features in the yard areas around the Wren Building and Brafferton that represent poorly documented historic outbuildings and quarters, and various areas of intact artifact deposits representing significant but otherwise poorly understood periods in the history of the College. For example, the survey work has turned up pottery shards, colonial-period clay wig curlers, thimbles and a Civil War bullet, Ballman said. He said the College realizes that such steps are a necessary part of any major project on such a historic campus.
“Such coordination that allows sufficient survey and documentation of significant archaeological resources to occur well in advance of construction is a manifestation of truly sustainable stewardship of the significant archaeological resources on the historic campus,” said Jones.
The purpose of the utility project is to replace the current 60 year old, deteriorated steam lines, which are no longer able to be maintained, with new pipes that will hopefully last until the next century, Ballman estimates. The new pipes will be laid in the aforementioned concrete casing: one for chilled water and one for steam, he said. The pipes will be insulated to further improve energy efficiency. Before any new pipes were placed, Facilities Management renovated the power plant behind the Facilities Management building and adding a chiller facility to the plant. The newly renovated and expanded plant will become the central location for heating and cooling for most of the historic campus, which means that the individual cooling towers outside of buildings like Blow Hall will eventually be removed, providing a visual benefit to the College. The new chiller plant will operate with variable frequency drive pumps for efficiency, and Patterson said that they have also already seen improvements in efficiency at the newly renovated power plant.
Because of the nature of the project, certain areas on campus, like parking lots, have been ripped up from time to time. Ballman sees this as an opportunity to restore the areas under construction back to code compliance (for example, ADA and storm water) and at no cost to the project optimize the space to fix or improve the traffic flow and parking.
“Any time the project touches something, if possible it should be brought back to a better condition,” he said.
For example, when a parking lot is repaired after construction, the project team will bring it up to code instead of restoring it to its previous condition. The project team has also separated sanitary water disposal from storm drains so that items like grease from kitchens do not get into the storm drains and flow into the Chesapeake Bay.
In the end, after the construction dust settles, the trees will still be standing, thanks to a dedicated project team and an innovative idea.