HomeMy WebLinkAboutNORTH COLLEGE MARKETPLACE, WETLANDS - FDP - 39-08/A - CORRESPONDENCE - (6)Steve Olt - Re: Fwd: North College Marketplace outfall storm sewer as-builts Page 1
From: Steve Dush
To: Glen Schlueter
Date: 4/12/2010 12:16:31 PM
Subject: Re: Fwd: North College Marketplace outfall storm sewer as-builts
Glen, I believe that christina vincent has hired dana to finish that project. If not ill ask steve olt to
coordinate with erica saunders...
----Original Message -----
From: Glen Schlueter
To: Steve Dush <SDush@fcgov.com>
Sent: 4/12/2010 9:11:43 AM
Subject: Fwd: North College Marketplace outfall storm sewer as-builts
Steve, Who should I work with on the wetland issues on North College Market Place?
>>> Wes Lamarque 04/09/2010 2:55 PM >>>
This email is to formally notify the Developer's Team that the City can not approve the construction of the
outfall storm sewer from the wetlands detention pond. The as -built drawings for the outfall storm sewer
were submitted to the City on April 8th. The profiles show a .5 feet rise from the invert in the pond to the
invert in the manhole located in Willox Lane. This would result in roughly 6 inches of standing water in the
wetlands/detention pond that would not be able to drain, compromise the quality of the wetlands, promote
mosquitoes, and other issues that would result from undesirable stagnant ponding. This is definitely not
what was represented to the City Council members that visited the site before construction. After the PDP
plans were approved, it was discovered that an electrical duct bank would be in conflict with the storm
sewer as originally designed. A new design to the utility plans was needed and the Developer's engineer
coordinated with the City and provided a revision to the approved drawings. There were several
discussions relating to the slope of the outfall storm sewer and the pipe material that would be allowed in
the right-of-way. The City agreed to allow used ductile iron pipe to help keep the invert of the storm sewer
as low as possible while crossing over the electrical duct bank and reduce the cost. The City also allowed
for the storm sewer to be laid flat and not have a positive slope for the outfall until the duct bank had been
crossed. The duct bank was at an elevation of around 4971.2, and the invert of the pond was designed at
4971.0. This would create a negative grade and elevation difference of .2 feet, which would create
ponding in the pond. Discussions then took place how the concrete electrical duct bank could be chipped
down a little, most likely the .2 feet difference in elevation. This would allow for the storm sewer to have a
0 percent slope until the pipe crossed the duct bank, and then the pipe would flow down as designed to
the swale outfall. This is still not ideal, but the City agreed to this solution. One idea that was considered
was to have a minimal positive slope to the manhole upstream of the duct bank and then a rise in the
manhole to match the elevation over the duct bank which would effectively be a 0% slope. This idea
would cause a place for sediment to collect so it was not chosen. The choice of laying the storm sewer
flat, 0% slope, was considered the best option. There was also a time constraint with this revision. The
Developer's consultants informed the City that the Contractor was ready to install the pipe immediately,
and that delays would cost the Developer money. The City expedited the review of these revisions and
did not require the revisions to be written at that time. It was agreed that the revisions could be shown on
the as-builts. Unfortunately, the as-builts submitted do not reflect the revisions discussed previously.
CC: Steve Olt, Christina Vincent, Ted Shepard