B08_-_Atch_1_-_SOW.pdf

U.S. Department of the Interior National Park Service Death Valley National Park

6/14/2023

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Statement of Work

Repairs And Maintenance to Concrete Roof of Stovepipe Wells Potable Water Storage Tank

PMIS # 324011

PART I

A. Introduction The government requires repairs and maintenance to be made to the below-grade concrete roof of a water tank used in a potable water system. Installation of bollards to protect the roof from vehicle traffic is also required.

B. Background The 20,000-gallon water tank at Stovepipe Wells is a component in the Stovepipe Wells public water system, serving visitors, concessioner operations, and staff housing. The tank is below grade, with soil cover over the roof. Surface water run-off in the Stovepipe Wells area is very corrosive, which causes rust of rebar and spalling of concrete in concrete structures. Any cracks in the water tank roof are exposed to surface water run-off and the potential for corrosion.

Additionally, cracks in the water tank roof are a route of contamination where surface water runoff can enter the public water system. The tank roof has been inspected at two very limited locations (SW corner and NE corner) and cracks exist in those locations. Additionally, damage has been caused to the tank roof in at least one location because the buried edges of the roof are not identified on the ground surface.

C. Scope Furnish all labor, materials, tools, equipment, and services necessary for:

• Use epoxy injection to repair cracks in the 10 foot by 26 foot concrete roof of the 20,000-gallon Stovepipe Wells potable water storage tank located in Death Valley National Park. Roof has approximately 1.5 feet of soil cover.

• Coat entire roof surface with a bituminous waterproof membrane which extends down the vertical sides of the tank to a level 2 inches below the roof/wall joint.

• Install 8 bollards around the perimeter of the tank to prevent future damage by vehicle traffic.

D. Applicable Documents

4.1. Structural Crack Repair by Epoxy Injection (ACI RAP-1) by Brian F. Keane published by ACI

International.

4.2. Manufacturer specifications and instructions shall be followed for each approved product.

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PART II

E. Technical Requirements

5.1. Initial investigation and identification

5.1.1. Roof load capacity is unknown, contractor is to take care not to overload the roof and repair any damage that occurs in soil removal and placement.

5.1.2. As directed by Contracting Officer’s Representative (COR), identify location(s) at worksite for temporary soil placement.

5.1.3. Remove soil layer from tank roof. Soil layer over roof is approximately 1 to 2 feet thick.

5.1.4. Excavate around perimeter of tank to a depth and width needed to complete work as specified.

5.1.5. Clean the surfaces which are to be membrane coated with pressure-washer.

5.1.6. Perform an inspection of roof and identify all cracks.

5.2. Crack repair

5.2.1. Prepare identified cracks as specified in the document Structural Crack Repair by Epoxy Injection.

5.2.2. Repair cracks using procedures described in the document Structural Crack Repair by Epoxy Injection.

5.2.3. Remove epoxy injection ports according to the document Structural Crack Repair by Epoxy Injection.

5.3. Membrane sealant

5.3.1. Clean, and prepare the concrete surface to be coated, following the document Structural Crack Repair by Epoxy Injection, and the Concrete Primer manufacturers specifications.

5.3.2. Apply Concrete Primer according to manufacturer specifications.

5.3.3. Apply Concrete Membrane Sealant according to manufacturer specifications.

5.4. Backfill soil around and over tank roof

5.4.1. Allow any manufacturer required time for crack repair compound and concrete sealant to cure.

5.4.2. Replace soil within excavated area around tank sides, compact to 95% of maximum density.

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5.4.3. Replace soil on top of tank roof. Compaction may not be possible above roof due to roof loading concerns. Level of roof compaction to be determined by Park representative.

5.4.4. Re-establish markings for roof outline, to be used for placement of bollards.

5.5. Install bollards around roof outline.

5.5.1. Identify and mark locations for bollards according to specifications as described on Diagram of Bollards.

5.5.2. Install bollards vertically plumb with 3 feet of the pipe encased in concrete footings below grade and 3 feet extending above grade.

F. Product Specifications

6.1. Structural Crack Repair Epoxy

6.1.1. Basis of design: Provide Sikadur®-35 Hi-Mod LV or approved equal.

6.2. Cap Seal Epoxy

6.2.1. Basis of design: Provide Sikadur®-31 Hi-Mod Gel or approved equal.

6.3. Concrete Primer

6.3.1. Basis of design: Provide Sikalastic® PF Lo-VOC Primer or approved equal.

6.4. Concrete Membrane Sealant

6.4.1. Basis of design: Provide Sikagard®-7600 HG or approved equal.

6.5. Bollards

6.5.1. Eight (8) bollards to be installed at locations around tank perimeter as identified on Diagram of Bollards.

6.5.2. Consist of 6-foot lengths of 6-inch nominal diameter SCH-80 structural steel pipe.

6.5.3. Shall be installed 3 ft deep in concrete footings which are at least 16 inches in diameter.

6.5.4. Entire length primed and painted. Prepare metal surface and apply primer and paint according to manufacturer specifications.

6.5.4.1. Primer

6.5.4.1.1. Basis of design: Provide Sherwin Williams All Surface Alkyd Enamel Primer or approved equal.

6.5.4.1.2. One (1) coat.

6.5.4.2. Paint

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6.5.4.2.1. Basis of design: Provide Sherwin All Surface Alkyd Enamel or approved equal.

6.5.4.2.2. Two (2) coats.

6.5.4.3. Color: Submit at least five (5) paint color swatches in beige/tan for approval and choice.

6.5.5. During installation, length of bollard shall be filled with concrete until it is level and smooth with the top of bollard.

G. Deliverables

7.1. Daily log detailing the work accomplished.

7.2. Final report detailing the work done to meet crack repair compound and sealant manufacturers specs, including amount of repair product which was used on the site, length of cracks identified and sealed, gallons of primer and sealant applied. Due within 2 weeks of effective completion of work.

PART III

H. Security

8.1. None.

I. Place of Performance

9.1. Stovepipe Wells water treatment plant in Death Valley National Park. Access to worksite is from CA HWY 190, approximately 0.75 miles down the graded dirt/gravel road to the Mosaic Canyon Trailhead. See Worksite Location Map.

J. Period of Performance

10.1. One hundred twenty (120) days from contract award date.

K. Special Considerations

11.1. None.

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PART IV

L. Price Schedule

ITEM NO. ITEM QUANTITY & UNIT UNIT PRICE TOTAL

1 Project preliminaries 1 LS @ $___________ = $___________

2 Mobilization and demobilization

1 LS @ $___________ = $___________

3 Excavation and backfill 1 LS @ $___________ = $___________

4 Tank roof crack prep & repair by epoxy injection

1 LS @ $___________ = $___________

5 Prep and apply concrete membrane sealant

1 LS @ $___________ = $___________

6 Furnish 8 painted bollards, 6’x6”-dia SCH-80 round structural steel pipe

8 EA @ $___________ = $___________

7 Install 8 bollards 3’ deep in 16”-dia concrete footings

8 EA @ $___________ = $___________

8 Project Closeout 1 LS @ $___________ = $___________

TOTAL BASE

PRICE = $___________