St Joseph-CS020509 MEMORANDUM
FROM THE
DEPARTMENT OF ENGINEERING
To:
From:
Date:
RE:
Jim Witt, City Manager
Kenneth M. Griffin, P.E., Dir. of Engineering/Public Works
May 9, 2002
St. Joseph's Sanitary Sewer Force Main
This memo is written as a follow-up to several conversations we have recently had concerning the
approximately $157,000 increase in cost for the installation of the City's 30" sanitary sewer force main
across St. Joseph's property. The original agreement with St. Joseph's had an installation cost of
$312,119. This was based on a set of preliminary plans from November 2001. The revised cost from St.
Joseph's', based on the final plans, is $469,535, a difference of $157,416.
You may recall during our conversations that in early 2002 it was brought to our attention that a retaining
wail was being proposed over the top of the new sanitary sewer force main. The toe of the retaining wall
would have precluded the City from ever accessing the sanitary sewer in the event that some type of
maintenance was needed. The only two options available were 1) for St. Joseph's to pull the retaining
wail into their property, totally outside of the sanitary sewer easement thereby reducing the developable
land; or 2) for the City to relocate its sanitary sewer force main. At, er discussions, the City decided to
work with St. Joseph's and relocate our sanitary sewer force main. Once the final plans were submitted to
the contractor, a revised cost estimate was provided to the City. Approximately $105,000 of the increase
in cost can be attributed to changes made from the preliminary to the final plans. Those changes include
the addition of the following: 1) 30" gate valve; 2) flanges; 3) 32 feet in length; & 4) epoxy lining to
preserve the longevity of the force main.
However, the relocation caused a deeper sanitary sewer installation through the St. Joseph's project. This
was because moving onto St. Joseph's site caused the proposed force main to come in conflict with the
onsite utilities, thereby requiring it to be deeper in some locations. Also, because we had to come onto
the site further and then near the south end of the site go back to the original alignment two additionai
bends were required for the installation of the force main. The cost for the pipe being installed deeper and
the two bends is approximately $50,000.
In essence, about 2/3's of the increase in the cost is due to the epoxy lining and changes to finalize the
plans. The other 1/3 is due to the requirement to be deeper to miss some of the onsite utilities. I had
originally told St. Joseph's representatives that approximately $40,000 of the increase was due to moving
on site however I failed to include the two additionai bends. At this point, I am unsure of the status of
their response to the fact that their retaining wall on top of our sewer line caused a redesign. That
redesign in mm caused design changes to increase the cost and a portion of that increase in cost should be
shared by St. Joseph's.
If you have any questions I will be happy to discuss them with you. If not, I will keep you informed.
"CITY OF COPPELL ENGINEERING - EXCELLENCE BY DESIGN"