Attachment 7 - Seed Project SOW.pdf

STATEMENT OF WORK

FOR THE CONSTRUCTION OF

REPAIR B164 SANITARY SEWER LATERAL

AT

ALTUS AIR FORCE BASE, OKLAHOMA

Project Number:

AGGN 201002

06 FEB 2020

Attachment 7 for FA441920R0001

1. BACKGROUND:

March 2019, Engineering Flight initiated a suspected sinkhole investigation at B164. The Sinkhole was within three (3) feet of the building and it possessed serious threat to the building foundation. Normally sinkhole collapse features tend to be associated with specific rock types, such as evaporates (salt, gypsum, and anhydrite) and carbonates (limestone and dolomite) and the rock type most often associated with catastrophic sinkhole formation because these rocks are susceptible to dissolution in water and the formation of cavities. Initial investigation by Civil Engineer found that soil in the sinkhole or around the sinkhole at B164 did not show limestone, carbonate rock, salt beds, or rocks that can naturally be dissolved by groundwater circulating through them.

This building is under renovation. Construction work in the area or collapse sanitary sewer was thought to have caused the issue. Most of the time the sudden subsidence associated with the localized collapse of subsurface cavities (sinkholes) happen because of underground broken water/wastewater line.

2. SCOPE:

The scope of this project is to excavate the soil from the existing lateral sanitary sewer line that connected with the building Women's 1021 toilet plumbing, Men's 1086 and 1080 Women's 4” Toilet plumbing. The 4" B164 sanitary sewer will be connected to new 6" PVC Sanitary Sewer that travel south to north. The 6" PVC gravity sanitary sewer laterals will meet the 8" Sanitary Sewer Main at the parking lot between Manhole 93D and Manhole 93C with a continuos slope of 1/8 “ per feet (1.04%) for gravity flow in accordance with the International Plumbing Code.

Install approximately 300 L.F. of 6” PVC sanitary sewer lateral pipes, sewer service connection, a clean-out every 100 L.F., rock support for the new pipes, bed the new pipe and then refill the excavation and reestablish grass over the grassy area. Perform removal of asphalt pavement, concrete curb and gutter, concrete sidewalks and replace with the portland cement concrete as per drawing and specification.

3. DESCRIPTION OF WORK:

a. Excavate soil from on top of existing sanitary sewer lateral pipe and down to the 8" sanitary sewer main at the parking lot. Where trenches lie within portland cement concrete, or asphalt sections, shall be saw cut before the paving is removed.

b. Hand digging will be required next to the existing HVAC Chiller Pad. Dig straight down and minimizing side digging as much as possible.

c. All saw cut shall be neat, vertical, true lines and no excavation will be permitted outside limits of the cuts.

d. Excavated asphalt and concrete surfacing materials shall be hauled from the job immediately and shall not be used in the backfill.

e. Demolish existing sanitary sewer lateral pipes from excavation.

f. Remove existing metal fence as necessary to complete the project.

g. Install new PVC sanitary sewer lateral pipe, clean-out, portland cement concrete sidewalks, gutters and parking lot trench section as per drawing.

h. If the Contractor excavates more trench than what he can install pipe in by the end of the working day, the excess length of trench must be backfilled prior to the Contractor leaving the work site for the day.

i. Contractor shall provide all pipes, fittings and paving materials as per specification requirements.

j. The trench shall be brought back to grade with native soil class II material, as described in ASTM D2321, and compacted to a minimum Standard Proctor Density specified in the drawing and specification.

k. Reinstall metal fence back.

l. Re-establish vegetation as per UFGS 32-92-23 section 3.

4. PROJECT REQUIREMENTS:

a. Contractor will be responsible for all shoring on site.

b. The Contractor shall coordinate the equipment/material lay down area prior to start of construction of the project.

c. Submit a concrete mix design for each strength and type of concrete and obtain mix design approval from the contracting officer prior to concrete placement.

d.

e. B164 will remain occupied and provisions for work around will be responsibility of the contractor.

5. GENERAL REQUIREMENTS:

a. All work performed on this project shall meet local, state, federal and DOD codes as well as adhere to all temporary environmental controls outlined in Specification Section 01 57

19.00 20.

b. The Government depends on the existing as-built drawings provided by previous Contractors for the accuracy. The Contractor is advised to field-verify all required information before providing a proposal.

c. The Contractor shall be required to accomplish various other small items of incidental work which may become necessary to complete the project in a satisfactory and workmanlike manner meeting the approval of the contracting officer or their designated representative. The Contractor shall include all such items of work as part of their detailed estimate for the work to be performed.

d. The Contractor shall provide all labor, materials, travel, equipment and supervision necessary to perform all work required for this project.

e. Damage to the building, utilities or any other element during the execution of this project shall be repaired and restored to its original condition by the Contractor provided workers, skilled in trades involved, at no additional cost to Government.

END OF SOW