December 13, 2019 Page 2
20191213 Change Order Review Letter.docx 3066.18
Over/Under Quantities
As explained in our Change Order #1 review letter, dated September 26, 2019, the latest
Type If Permit Modification Application included several design changes needed to
demonstrate that the project conforms to the groundwater separation requirement of the
New Hampshire Solid Waste Rules (Rules). The design changes primarily affected earthwork
volumes and leachate collection system (LCS) piping quantities. Because Charter achieved
substantial completion of Phase III, there is now sufficient as-built survey available to finalize
the Phase III quantities.
Sanborn Head reviewed Charter’s quantities and their computer-generated surface used to
calculate their updated quantities. During our review, we identified that Charter was
accounting for geosynthetic material installed beyond the limit of waste containment area.
After discussing with Charter, and reviewing the Phase III bid item definitions, it was agreed
that geosynthetic material installed beyond the limit of waste containment area should be
neglected.
Based on the discussion included in our Change Order #1 review letter related to the LCS
piping (Section 8}, it was agreed upon that the design changes warranted a unit price
increase of $9.81 per foot ofipipe. The surveyed length of LCS piping installed varied slightly
from the estimated value. The lump sum cost provided by Charter for the additional pipe,
stone, and labor associated with the design changes did not correlate with the $9.81 per foot
cost previously agreed upon. After discussing with Charter, it was agreed that the lump sum
amount provided by Charter should be reduced based on the $9.81 per foot cost previously
agreed upon.
Out of Scope Work Item — Building Generator Update
In accordance with Condition 18 of the City’s Phase III permit, the City needs to ensure the
availability of auxiliary power pursuant to Env 805.06(n) and (0). Because the original sump
riser building electrical system design did not provide the City the ability to operate via an
auxiliary power source (i.e., a generator}, Sanborn Head and Charter worked to modify the
existing design in order to be compliant with the Rules. The modifications included
rearranging panel equipment and furnishing and installation of anew NEMA rated electrical
switch gear to allow the City-owned emergency generators to be connected and operate the
sump riser building mechanical components.
During a recent site walk-through with Sanborn Head, Charter indicated that a portion of the
PVC piping was proposed to be heat-traced. It was agreed upon that all of the PVC piping and
valving within the sump riser building should be heat traced for protection against freezing.
As such, Charter includes the additional labor and material costs associated with adding the
additional heat-tracing.
As documented in Exhibit 2, Charter’s cost of $9,312.00 does not included overhead costs,
thus it is recommended that the cost for this item be paid in full.
SANBORN I HEAD
