Res 231-82 12/21/1982RESOLUTION NO. , j
RESOLUTION APPROVING CHANGE ORDER #1, AND
AUTHORIZING THE REPLACEMENT OF UP TO 3888
SQUARE FEET OF FILTER UNDERDRAINS, CONTRACT
NO. I , SECTION I, WATER TREATMENT PLANT
IMPROVEMENTS
WHEREAS, the City of Wichita Falls and Brown-McKee, Inc. as
contractor entered into a contract April 14, 1982, wherein said
contractor agreed to construct the Water Treatment Plant Improvements;
and,
WHEREAS, the estimated unit quantity of filter underdrain replace-
ment is 3,888 square feet; and,
WHEREAS, Change Order #1 for extra work and delay in the amount
of $45,661.49 has been submitted.
NOW, THEREFORE, BE IT RESOLVED BY THE BOARD OF ALDERMEN OF THE
CITY OF WICHITA FALLS, TEXAS, THAT:
The filter underdrain replacement of up to 3,888 square feet is
authorized, and Change Order #1 in the amount of $45,661.49 is authorized
and the City Manager is empowered to execute same for the City of Wichita
Falls.
PASSED AND APPROVED THIS THE 21ST DAY OF DECEMBER, 1982.
M Y 0 R
ATTEST :
Y12ZW=%'.4.-&-/)
CITY CLERK
Page 8 of 8 Pages
Agenda Item No.
v,
CHANGE ORDER
Order No. 1
Date: December 10, 1982
Agreement Date:
NAME OF PROJECT:Water Treatment Plant Improvements Contract No. 1,
Section I
OWNER: Wichita Falls, Texas
CONTRACTOR: Brown McKee, Inc.
The following changes are hereby made to the CONTRACT DOCUMENTS:
Justification: See Attached
Change to CONTRACT PRICE:
Original CONTRACT PRICE 394,230.50
Current CONTRACT PRICE adjusted by previous CHANGE ORDER $ 394,230.50
The new CONTRACT PRICE due to this CHANGE ORDER will be (increased) (decreased)
by: $ 45,661.49
The new CONTRACT PRICE including this CHANGE ORDER will be $439,891.96
Change to CONTRACT TIME:
The CONTRACT TIME will be (increased) (decreased) by 30 calendar days
The date for subst ntial completion 9f all work will_be May 15, 1983 date)
Requested by: 2/2-7/8,2,
Black & Veatch
Recommended by: / "
lack hh ac y5-2/8;7
lack & Veatch
Accepted by: L. Si . _ r. ' i
J
rown-McKee, I c.
Ordered by: i 4 2 - 3 0- ? 2-
City of Wichita Falls, Texas
Federal Agency Approval (where applicable) Not applicable
WICHITA FALLS, TEXAS)
9070-1, SECTION I )
CHANGE ORDER NO. 1 )
COl-1
BLACK & V E A T C H
CONSULTING ENGINEERS
KANSAS CITY. MISSOURI
DALLAS OFFICE MAILING ADDRESS
5728 LBJ FREEWAY. SUITE 300 POST OFFICE BOX 402004
TEL. (214) 386-0001 DALLAS,TEXAS 75240
Wichita Falls, Texas B&V Project 09070
Water Treatment Plant Improvements B&V File G-1.0
Contract No. 1, Section I December 10, 1982
CHANGE ORDER NO. 1
COST SUMMARY
Net Increase in
Extra Work Item Contract Price
1. Filter Media. Providing and installing
12 inches of new filter gravel in lieu
of reusing existing gravel and providing
and installing 4 inches of new coarse
filter sand on top of the new gravel
filters No. 1 through 9 and 11. 31,682.22
2. Other Extra Work
a. Filter Manhole Cover Removal and
Replacement. The removal of manhole
covers to the center flumes in Filters
No. 1,2, and 4 (City personnel will
remove covers in Filters No. 2,5, and 6)
and the replacement of manhole covers
in Filters No. 1 through 6. 1,143.74
b. Experimental Filter Underdrain
Flushing and Salvaging. Attempts to
flush sand from underdrains in Filters
No. 1,4, and 9 and attempts to remove
and salvage underdrain blocks in
Filter No. 4. 2,418.50
c. Costs Incurred Due to Construction
Delay. Costs incurred by the Contractor
for equipment rental, field supervision,
field overhead, and move-out and in due
to construction delay. 10,417.00
Total Increase in Contract Price 45,661.46
WICHITA FALLS, TEXAS)
9070-1, SECTION I )
CHANGE ORDER NO. 1 )
CO1-2
CHANGE ORDER NO. 1
JUSTIFICATION OF EXTRA WORK
Extra Work Item
1. Filter Media. To protect the filters from future media upset
as encountered in the existing filters and to aid in keeping
sand from again reaching the underdrains, it is necessary to
replace the existing filter gravel with a thicker layer of new
graded gravel. Also, a new layer of coarse sand on top of the
gravel is required. The new gravel and sand will form an im-
proved support material and barrier for the filter sand above.
2. Other Extra Work
a. Filter Manhole Cover Removal and Replacement. After re-
moval of the filter media, uneven backwash flow distribution
was observed, indicating flow blockages in the underdrains.
Access manholes to the filter center flumes were opened to
permit a more thorough inspection of the underdrains. Re-
placement of the manhole covers will also be required.
b. Experimental Filter Underdrain Flushing and Salvaging. A
thorough investigation of the underdrain system in Filter
No. 4 was required to better determine the extent of sand
and grout blockages. Experimental flushing of the under-
drains and underdrain block salvage work were attempted to
evaluate alternative methods for rehabilitation of the
filters.
c. Costs Incurred Due to Construction Delay. Upon discovery
of the entensive filter underdrain blockages, filter con-
struction was delayed until the extent of the problem was
fully evaluated, alternative solutions were examined, and
a final recommendation made. Although every effort was
made to conduct these evaluations as quickly as possible,
construction was delayed approximately one month. Costs
incurred by the Contractor due to this delay included
equipment rental, field supervision, field overhead, and
move-out and in expenses.
WICHITA FALLS, TEXAS)
9070-1, SECTION I )
CHANGE ORDER NO. 1 )
CO1-3
Filter Gravel. The filter gravel shall be new. Either of the following
gradations of new filter gravel may be provided. Total gravel depth in
each case shall be 12 inches.
Layer._Above Depth of Retained on Passing
Filter Bottom Layer in Inches Sieve Size Sieve Size
a. Gradation Type A.
1st 3 1/2" 1"
2nd 3 1/4" 1/2"
3rd 3 1/8" 1/4"
4th 3 No. 8 1/8"
b. Gradation Type B.
1st 3 5/8" 1"
2nd 3 3/8" 5/8"
3rd 3 3/16" (No. 4) 3/8"
4th 3 No. 8 3/16" (No. 4)
All existing filter gravel shall be stockpiled by the Contractor for hauling
away from the site by the Owner.
New Coarse Filter Sand. The bottom layer of coarse sand shall be new, 4 inches
thick, and shall be placed directly over the top layer of gravel. The coarse
sand material shall be as specified in Addendum No. 1.
Other Filter Sand. The other filter sand to be placed on top of the new
coarse sand layer shall be as originally specified except as modified herein.
If the Contractor elects to use the existing filter sand for placement above
the new coarse sand, the thickness of the coarse sand layer shall be as
required to yield a top elevation of the finished coarse sand layer equal
to 963.50.
All excess existing filter sand shall be stockpiled by the Contractor for
hauling away from the site by the Owner.
WICHITA FALLS, TEXAS)
9070-1, SECTION I )
CHANGE ORDER NO. 1 )
CO1-4