A04_SOW.pdf

DEATH VALLEY

NATIONAL PARK

Repair Non-Potable Water Line at Furnace Creek

PMIS NO. XXXXXX

PROJECT SCOPE OF WORK

NATIONAL PARK SERVICE

PACIFIC WEST REGION

September 4, 2023

THIS PAGE INTENTIONALLY LEFT BLANK

PMIS XXXXXX / Repair Non-Potable Water Line Death Valley National Park

1.0 Overview

In late August, 2023, the Park experienced a historic flood event. This flood event severely damaged Park infrastructure.

The Park has an agreement to provide non-potable water to the Xantera Ranch property which includes a golf course and significant landscaping. This non-potable water is served from a collection gallery which collects water from approximately 35 ft below grade. The piping between the collection gallery and existing water meter vault is 12” diameter pipe. The 12” pipe reduces to 6” to accommodate the 6” water meter in the vault, and then expands back to 12” pipe at the vault outlet. The non-potable water line near the meter vault was exposed due to erosion from the initial flooding scour. After the initial flooding scour, large rocks and debris impacted the exposed pipe and created a large leak.

This water leakage has created surface drainage and also caused the nearby meter vault to flood with water and debris.

2.0 Project Location

The meter box and water line break are located near the Xanterra Inn at approximately the following coordinates:

Latitude: 36.452080°

Longitude: -105.505928°

Figure 1: Map showing approximate location of the non-potable water line break and existing vault. The Furnace Creek Inn and

Ranch are also shown. See Figure 2 and 3 for additional details.

APPROXIMATE

LOCATION OF

PROJECT

Figure 2: Map showing existing meter vault and approximate location of the non-potable water line break. Existing vault contains 6”

Ductile Iron Pipe -> 6” Water Meter -> 6” PVC Pipe -> 6” Gate Valve -> 6” to 12” Reducer ->12” PVC Pipe w/ ARV.

3.0 Scope of Work

Figure 3: Map showing proposed work.

APPROXIMATE

LOCATION OF

BREAK

EX. VALVE AND

WATER METER

VAULT

View: Looking West

TRENCH APPROXIMATELY

250’ TO DIVERT WATER

AWAY FROM PIPE BREAK

AND VAULT

INSTALL NEW 12”

GATE VALVE AND

REPAIR WATER

LINE BREAK

EXCAVATE TO EXPOSE EX.

12” TO 6” REDUCER ON

UPSTREAM SIDE OF VAULT

PUMP OUT WATER AND

DEBRIS FROM EX. METER

VAULT

REMOVE EX. PLUMBING

FIXTURES, CHECK AND

CLEAR ANY OBSTRUCTIONS,

AND REASSEMBLE WITH

NEW GASKETS

APPROXIMATE

LOCATION OF EX. 12”

NON-POTABLE WATER

LINE BREAK

EX. 12” NON-POTABLE

WATER LINE

APPROXIMATE

ELEVATION: 84’

APPROXIMATE

ELEVATION: 94’

EX. GATE VALVE

• Trench approximately 250 feet to redirect water and drain the existing non-potable water line break area before commencing repair work in the vault and the pipe breakage. Trench will be backfilled and restored to the natural condition after repair work is completed.

• Install 12 inch gate valve at the non-potable water line break. Pour 4” thickness concrete pad around the valve riser box with rebar. Concrete shall be 2 ft x 2 ft. Install permenant gate valve location marker with steel post driven into the soil. Height of marker to be 3 ft above grade.

• Repair the non-potable water line break with the gate valve, repair couplings, and new pipe segments.

• Pump out existing vault of water, sediment, and debris.

• Excavate and expose 12” to 6” reducer that is on the exterior of the inlet side of the existing meter vault.

• Existing plumbing in and around the existing meter vault shall be removed and cleared of any obstructions from debris, sediment, or anything foreign material. The plumbing shall then be reassembled in the same orientation with new gaskets. Existing plumbing has a mixture of mechanical joints and flanges. These items consists of:

o 6” Ductile Iron Pipe o 6” Water Meter o 6” PVC Pipe o 6” Gate Valve o 6” to 12” Reducer o 12” PVC Pipe w/ ARV

• Seal inlet and outlets of pipe protrusions in existing vault to prevent water intrusion

• Verify existing 6” water meter is functional.

Figure 5: Ex. gate valve on upstream side of meter

Figure 4: Pipe repair from the past year that is close to the new pipe break

4.0 Definition of Contract Line Items

Contract Line Item No. 01 – Install shutoff gate valve and repair non-potable water line break

All disposal costs, excavating, backfill, compaction, trenching, dewatering, gate valve, piping, mechanical joints, gaskets, valve box, concrete, rebar, gate valve post marker, repair couplings, bolts, nuts, work, labor, materials, and appurtenances to complete the work as specified.

Contract Line Item No. 02 – Pump out existing pump vault and clear plumbing blockage

All disposal costs, pumping, sediment and debris removal, gaskets, mechanical joints, bolts, nuts, work, labor, materials, and appurtenances to complete the work as specified.

5.0 Technical Details

1. The water line break is approximately 4 ft below surface grade. The water has already scoured the soil away and left a hole in break area. The pipe should be located close to the bottom of the pooled water in the hole.

2. Contractor to take and submit to NPS a minimum of 5 photos showing ex. pipe damage and obstruction causing flow blockage.

a. These photos are intended to document the reasons why the non-potable water system was not working

3. Contractor to field verify pipe type and compatibility with proposed mechanical joints, flanges, a repair couplings.

4. Contractor to clean site after completion of project.

5. Access to Park will require coordination with the Park, as the Park is closed due to the flood damage. Contractor shall work with Park safety to ensure safety within the Park during construction operations.

6. Park has severely damaged roadways. Contractor shall use extreme caution when navigating to the work site.

7. Based on the available information, a blockage may have occurred at the exterior 12” to 6” reducer next to the exterior gate valve. This would be a logical place to start looking for a blockage.

8. No flanged joints allowed for buried application.

9. Existing 6” water meter appears to be functional, but no flow is being detected.

6.0 Submittals

Contractor to provide the following submittals to NPS for review and approval:

a. Gate Valve

i. With use of mechanical joint:

1. Mueller 4-12 inch A-2361 RWGV MJXMJ (non-rising stem) or approved equal

2. Mechanical Joint: EBAA Iron MEGALUG specific to pipe type or approved equal

ii. Without use of mechanical joint:

1. Mueller 12 inch resilient wedge gate valves with hymax grip® restraint or approved equal

b. Repair Couplings

i. ROMAC Alpha or approved equal

c. Pipe

i. PVC C900

d. Gaskets

e. Valve Box with Locking Lid

f. Concrete Filler and Sealant

g. Concrete for gate valve pad

i. Quikcrete (4000 psi) or approved equal is acceptable for this application

7.0 Attachments – N/A