Attach-1-SOW.pdf

--STATEMENT OF WORK--

PIPE FABRICATION, INSTALLATION AND REMOVAL ON

DALE BUMPERS WHITE RIVER NWR

Dale Bumpers White River NWR

St. Charles, AR 72140 July 15, 2020

This work includes; (1) the removal of two existing water control structures, (2) the construction and (3) the installation of a full round riser water control structure and pipe.

This work is to occur approximately 9 miles southeast of Tichnor, AR (Figures 1 and 2).

Line Item #1: Remove two existing water control structures

The contractor shall provide all equipment and labor to remove two existing water control structures (hereafter referred to as the East WCS and West WCS). The existing water control structures consist of a concrete headwall on both ends of the plastic pipe (see Figures 3 – 4). The existing pipes are approximately 45’ long.

• For the East WCS

a. Remove the existing pipe and haul off site.

b. Leave concrete headwalls in place and backfill dirt around them. Dirt will be backfilled around headwalls and where the pipe was removed. When backfilling where the pipe was, use dirt that was removed to get as close to the existing elevation of the levee as possible.

• For the West WCS

a. Remove the existing pipe and haul off site.

b. Remove concrete headwalls and set to side out of the work area.

Line Item #2: Build full round riser water control structure

The contractor shall fabricate a steel full round riser water control structure according to the plans in Figures 5 – 10. Not shown in the figures below: (1) Risers and pipes should be epoxy coated and (2) a removable beaver guard should be placed on each end of the pipe (total of two). The fabrication plans are summarized in the description below:

• The riser is to be constructed of 48”, 5/16” smooth steel pipe (Figure 5).

• Welded to the upstream side of the riser will be 12.5’ of 24”, 5/16” smooth steel pipe (Figure 5).

• Welded to the downstream side of the riser will be 10’ of 24”, 5/16” smooth steel pipe (Figure 5).

• An additional 40’ piece of 5/16” smooth steel pipe will be required (see line item #3 below).

• Flatbar for stoplog guide should be welded with a continuous weld from top to bottom on the outside channel formed by the two flatbars (Figures 7-8).

• Stoplog guide should have a spacing to accommodate boards that are

1 ¾” wide (Figure 7).

Line Item #3: Install full round riser water control structure and 40’ pipe

The contractor shall provide all equipment and labor to install the water control structure from Line Item #2 above.

1. The full round riser water control structure and pipe will be installed in the same location where the west water control structure is removed.

2. The pipe and structure should be set at the same elevation as the existing structure that is being removed (the existing pipe is approximately 5’ deep).

3. Before placing the structure in the ground, the contractor will weld a 40’, 5/16” smooth steel pipe to the 10’ of pipe on the downstream side of the riser.

4. The contractor will cover the riser and pipe with dirt to the same elevation as the existing ground on top of the levee.

5. SOW Questions contact Jay Hitchcock 870-282-8246 or Charles Sloan 870 282-8205 email Charles_Sloan@fws.gov

End

Figure 1. Location map of Levee A work area near Tichnor, AR.

Figure 2. Aerial image of work area.

Figure 3. Concrete dimensions for water control structures (upstream side).

Figure 4. Concrete dimensions for water control structures (downstream side).

Figure 5. Full round riser detail (not to scale).

Figure 6. Control structure detail (not to scale).

Figure 7. Stoplog guide details (view looking from above, not to scale).

Figure 8. Stoplog guide details (side view from bottom, not to scale).

Figure 9. Riser step details (not to scale).

Figure 10. Riser cover detail (not to scale).

NOTES:

1. Weld a 2” x 18” vertical strap to the bottom edge of the cover (around the entire circumference)

2. Cover size shall be determined by the riser diameter plus 2”

3. Hinged door length shall be determined by the riser diameter minus 1” either side of riser