NANCY CREEK TUNNEL
Report as of September 1, 2002

This is the fifth Report on the above subject. Should you wish to receive the first four, please e-mail me with your request. As before, I am reporting events to the best of my recollection and I will try to differentiate when I am offering an opinion. This Report may not be the position of the Technical Advisory Committee nor the City of Atlanta. 

The Technical Advisory Committee met on July 12, 2002 and again on August 30, 2002. 

The Tunnel Contractor, Obayashi, is proceeding on schedule. The R. M. Clayton Shaft site has been cleared and construction of the vertical Shaft wall should begin during the first week in September. Clearing at the Roswell Road Shaft site should begin in the second week and construction of that Shaft wall should begin in mid October. As soon as the Roswell site is cleared, the plan is to proceed to the Johnson Ferry site and begin the clearing there. By mid November, work on the Johnson Ferry Shaft is planned to begin. 

The City is relying on the DeKalb County Commission to authorize condemnations of DeKalb properties. DeKalb's action (or lack of action) may alter the schedule at Johnson Ferry. 

A neighborhood group in DeKalb County (DC3) has formed and has asked the City to investigate several options involving reduction and relocation of the Johnson Ferry Shaft to a site on Evergreen Drive. DC3's options deserve far more space to explain than I have room for here. The City's consultant, Jordan, Jones and Goulding (JJG), has provided us with an analysis of these options. JJG's recommendation is that we proceed as planned. If this comes to a vote at our Committee, I will support the JJG recommendation. Aside from cost increases and the potential of delays, I believe that changing the site just substitutes one person's backyard for another - and maybe worse as the Evergreen site looks much more sensitive to me. Please recall that when Obayashi originally bid to launch the TBM from Johnson Ferry, our Committee rejected that proposal. Similarly, we believed that we could not, in good conscience, transfer the impacts of excavation and truck traffic from our back yard to someone else's. 

Mike Robinson is the construction engineer on the Tunnel project and he works for JJG. Mike provided some details concerning the Shaft construction that will affect the impact to our neighborhoods. The Shafts will be constructed employing the "secant" method. This involves boring 36 inch diameter holes down to bedrock. The holes are filled with concrete after completion. These holes are bored in a circular pattern. The circle then forms the walls of the Shaft. After the concrete has cured, excavation can begin inside the circle. Little blasting, if any, will occur until bedrock is reached and, with the exception of the first several feet, the excavation will be conducted below the surrounding ground surface. At the Roswell Shaft site, the drilling logs indicate that there is soil to a depth of around 100 feet and then a mixture of weathered and fractured rock to a depth beneath the floor of the Shaft. In my opinion, it is probable that no blasting will occur in the first 100 feet and there exists a possibility that there will be little blasting for the balance of the Shaft construction. After the Shaft is constructed, a staging area for the Tunnel Boring Machine will be constructed. This area will be about 300 feet and will be constructed horizontally. Because of the construction techniques involved, I believe that the staging area will be blasted almost in its entirety but this will occur at a depth of 150 feet. 

Council Member Mary Norwood reported that she and Council Members Clair Muller and Howard Shook have realized the necessity of formalizing a process for direct neighborhood input on a day-to-day basis as construction proceeds. Therefore, a Citizen's Committee will be established. Two neighbors from the vicinity of each Shaft site (those being the areas of highest impact) will be appointed. The details of the responsibilities and the chain of command of the Citizen's Committee are being established at this time. 

The City attorney in charge of easement acquisition, Ms. Sally Mills, reported that, to date in Atlanta, 62 of the 318 easements have been acquired "by agreement". She expects that, ultimately, 70% will be obtained in this fashion leaving 30% that will have to be condemned. In DeKalb, far fewer easements are required and the results look similar.. 

Several property owners have objected to "waiver language" that is contained in the easement agreement. The easement agreement was adapted from an earlier form and in the haste to get notification out to property owners, the waiver language was not eliminated. This language is not applicable to the Tunnel project and can be struck from the agreement or upon request, the City will issue a modified agreement. Sally Mills informed us that, in either case the City will not rely on that language. . 

City and Obayashi officials and Nancy Jones, the driving force behind the concept and the creation of the Blue Herron Nature Preserve, have spent a great deal of time mitigating the impacts of the Roswell Shaft site on the Preserve. I believe that we owe much gratitude to these folks for the solution that appears to be at hand. Basically, Obayashi has reconfigured their site plan taking the silt pond away from the banks of Nancy Creek and the adjoining neighborhoods. They have realigned a conveyor belt and relocated the portable change rooms so as to miss trees. Still and unfortunately, four oaks from 9" to 16" are scheduled for removal from within the Preserve. Mike Robinson also indicated that they would be very receptive to a low impact solution to the stabilization of the Nancy Creel stream banks. Further meetings are planned.

At the August 30, 2002 meeting, the Technical Advisory Committee concentrated on a plan to remedy overflows in the lower Nancy Creek basin on a time schedule that is more immediate than the Tunnel will provide. This amounts to a cost-benefit analysis involving the probability of a menu of storm events (and thus, the probability of overflows), the number of houses affected and damage incurred, damage to Nancy Creek and the present and future costs and benefits of a relief pump station, to name a few. This decision must also be considered in light of the length of time that would be required to design, bid, build and test this pump station given that the Tunnel should be operational in three years. Data is being gathered for further deliberation at our next meeting on September 17, 2002. 

No Questions have been received so I cannot offer any Answers this time.