-----Original Message-----

From: Harold Cunliffe

Sent: Sunday, December 08, 2002 5:34 PM

To: Walda Lavroff; Ade Abon; Clair Muller; Gordon Certain; Howard Shook; John C. Wilson; Justin Wiedeman; Katy Bryant; Lucy Smethurst; Mac Ryland; Mary Norwood; Nancy Jones; Pat Gardner; Rick Daniel; Sally Mills; Sally Silver; Sy Liebmann; 'Sylvia Bangle'; 'Bill Dreyfoos'; 'Carine'; 'Frederik'; 'Jeffrey Groves - Brookhaven Assoc.'; 'Joan Smeltz'; 'Leah Knowlton'; 'Lisa Wargo - Brookhaven Newsletter'; 'Matt Lawson'

Subject: Harold Cunliffe's 6th Report on Nancy Creek Tunnel

Dear All:

Pasted below and attached in Word for those of you who wish to edit, is my 6th Report.  [The attachment was omitted from this web page.]

Harold Cunliffe

NANCY CREEK TUNNEL
Report as of December 6, 2002

This is the sixth Report on the above subject. Should you wish to receive the first five, 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 December 6, 2002 at the R. M. Clayton plant (RMC) and toured the project site.

RM Clayton Site (NW Atlanta)

The Tunnel Contractor, Obayashi, has completed 14% of the project. The R. M. Clayton Shaft has been excavated to a depth of 70 feet and concrete lined to 60 feet. Blasting has been required and so far, the shock waves have been lower than initially thought. No complaints have been received. The Tunnel Boring Machine (TBM) for the RMC segment is presently being rebuilt in Ohio. I was impressed at the compactness of the RMC site. It occupies far less space than its counterpart in Cobb. The contractor is also utilizing a large blasting mat that fits over the top of the shaft. This undoubtedly is contributing to the low impact of the blasting operation.

As a result of our Committee’s value engineering, the design team will consolidate two of the RMC lift stations in the RMC shaft. This revision is projected to save $10 - $15 million. Further, we will investigate the addition of a low-head pump at RMC. This will cost $3,000,000 but will bring some relief to homeowners on the lower stretches of the Nancy Creek in advance of the completion of the Tunnel. Further, this addition may pay for itself in the short term through energy savings.

Roswell Road Site (North Buckhead)

The Roswell [Road] site is being prepared. Pre-blast surveys within 1000 feet of the Shaft are ongoing. The sound wall construction is underway. The Roswell TBM is likewise being rebuilt. The Johnson Ferry site is still being planned and will be discussed later in this report.

All easements that are on the critical path have been obtained. As of December 2, 2002, 187 of the 320 required easements have been obtained. Forty-nine are scheduled for condemnation. All storm water ponds have been designed and all NPDES [National Pollutant Discharge Elimination System] Permits have been obtained.

Johnson Ferry Road Site (DeKalb)

In a special session of the Committee, the current decision of the construction of a Shaft at Johnson Ferry vs. a “shaftless” solution was re-examined.

First, the decision to reject Obayashi’s bid of staging one TBM from Johnson Ferry was discussed. This [previous decision] resulted in shifting 20,000 truckloads of excavation and 10 months of continuous operation from Johnson Ferry to Roswell. In addition, the construction was extended 3 months (perhaps resulting in 3 more months of downstream overflows) at an expense of $1,400,000. Notwithstanding these impacts, our Technical Advisory Committee was unanimous in its recommendation to reject Obayashi’s proposal because it did not conform to the way that the project had been represented to the various neighborhoods and, I believe, because of a sense the inequity involved in shifting this impact from an Atlanta jurisdiction to a DeKalb jurisdiction.

Next, we discussed the “shaftless” option at Johnson Ferry. The construction at Johnson Ferry is complicated by the requirement of two intake shafts. These intakes receive flow from existing interceptor lines. The current design contemplates that one of these intake shafts will be blasted underground from the bottom of the shaft to the point of interception with the existing sewer lines. With a shaftless solution, the construction of the intakes would have to occur after the Tunnel is completed. Thus, the intake construction is moved onto the critical path resulting in a 2 month extension to the construction schedule. A vent shaft would now also have to be constructed at the end of the tunneling operation adding a further month.

Next, logistical complications involving the TBM operation add another 1 ½ months. This includes pulling the TBM back to Roswell as opposed to lifting out of the Johnson Ferry Shaft and having to run the TBM an extra 300 feet for dismantling.

After the Tunnel is built, the concrete lining operation begins from Johnson Ferry and proceeds to Roswell. But the lining will not completely fill all the voids necessitating a “contact grouting” operation that commences as soon as the concrete liner reaches a strength of 2,000 psi. With a shaft at Johnson Ferry, the contact grouting can follow the lining operation but without a shaft, it must be staged from Roswell and thus, must be delayed until the lining operation clears Roswell. With the contact grouting now on the critical path, an additional 2 months must be added to the construction schedule.

Our analysis resulted in a 6 ½ month extension to the construction period. When asked to evaluate the same option, Obayashi speculated an additional 5 months would be required. Our Committee analysis indicated that an addition $1,000,000 would be expended and Obayashi concluded, $2,500,000.

The construction schedule currently has a “float” of 2 months before the penalties called for by the Consent Decree kick in. Once they do, the fine is $1,000,000 plus $5,000 graduating to $8,500 per day. “Spending” these additional two months at the initial stages of a project of this complexity would be ill-advised. Non compliance with the Consent Decree would certainly trigger a building moratorium. We did not attempt to calculate this cost. Likewise, we did not attempt to calculate the cost to public health stemming from additional overflows.

Many of these logistical concerns are brought about by the decision to construct one of the intake shafts utilizing an underground operation. The design team decided on this approach because of the impact of an “open cut” operation that must cross Nancy Creek and its environs. By employing the “open cut” method, it is believed that the Johnson Ferry Shaft could be reduced to 15 or 16 feet in diameter and that a potential savings of $1,000,000 could be realized with little impact on the schedule. In my opinion, the reduction in shaft size would result in a marginal decrease in construction impact at the shaft, but the open cut operation in Nancy Creek would be highly undesirable and remembered for years.

Nevertheless, the construction manager was asked to discuss this option with Obayashi. They were also asked to independently evaluate the construction schedule that would result from a shaftless and from a reduced shaft size at Johnson Ferry for our next meeting.

The option of shifting either a shaft or a shaftless termination point to Evergreen was briefly discussed. As discussed in previous reports, this would involve a realignment of the Tunnel into a zone of unstable rock thus greatly increasing the chance of ground water infiltration and / or the costs of mitigation of infiltration. It would also be located in a heavily treed area. Further during the early stages of design, Dekalb County indicated a preference of having the Tunnel terminate within Dekalb County.

Again, no Frequently Asked Questions were asked of me.