SOW_Repl_RV_Pad_Lift_Station_and_CCC_Cabin_Septic.pdf

Replace Lift Station at RV pads and CCC Cabin Septic System Page 1

CAPE HATTERAS NATIONAL SEASHORE

Outer Banks Group

Statement of Work

Replace the Lift Station Pumps at the Recreation Vehicle Pads on Loggerhead

Lane and Replace Tank and Drainfield on Cabin Rd in Buxton, NC

1.0 INTRODUCTION

The National Park Service (NPS) Cape Hatteras National Seashore (CAHA) has a requirement to replace the existing lift station mechanical components serving the Recreational Vehicle (RV) pads on Loggerhead Lane as well as a tank and drainfield on Cabin Rd in Buxton, NC.

2.0 CONSTRUCTION SITE LOCATIONS

This project has two site locations located approximately ¼ mile apart.

The RV Pad lift station is located on Loggerhead Lane adjacent to the Laundry Building in

Buxton, NC.

The septic tank and drainfield are located at the end of Cabin Rd near 46060 Cabin Rd, Buxton, NC, 27920.

Figure 1: Septic Tank and Drainfield at the end of Cabin Rd

Replace Lift Station at RV pads and CCC Cabin Septic System Page 2

3.0 BACKGROUND AND EXISTING CONDITIONS

There are 10 RV pads and a laundry building located on Loggerhead Lane in Buxton. The RV pads include a connection point for septic which tie together and drain to a septic tank. The

Laundry room washing machines also drain to the same septic tank. The tank is approximately

10 ft long and 5 ft wide. The tank is buried approximately 3 ft below grade with concrete risers up to grade level. The top of the tank is approx. 3 ft below ground level. The septic tank empties fluids into a lift station which pumps the effluent along Loggerhead lane to a raised drainfield. The lift station is housed within a shed and is an old design with motors located above grade with pumps below in a wet well. The pumps and motors are beyond repair and replacement parts are no longer available. The electrical and mechanical components are either non-operational, partially repaired to operate, or replaced with newer components and fashioned to remain operational. The concrete wet well measures approximately 4ft – 5 ft diameter and measurements show the height of the wet well to be approx. 5 ft, which would result in approx.

470 gal - 730 gal wet well. A slab is poured as the tank lid with an access hatch into the wet well below. The floor slab is approx. 12” - 18” below outside grade. A shed approximately 10 x 10 is constructed on top of the tank. Electrical controls for the lift station pumps and motors are mounted on the wall inside the shed. The laundry building adjacent to the lift station shed has an

Electrical panel which includes a branch circuit to provide power to the lift station. The pair of lift station effluent pump pipes rise up from the wet well lid, turn and exit the back of the shed, connect to a pair of gate valves, then wye together to a single force main located behind the shed.

See photos below. The pair of gate valves are located in a valve box immediately behind the lift station and can isolate the lift station.

Figure 2: Picture of Approximately location of septic tank near the RV Area and Lift Station Shed

Replace Lift Station at RV pads and CCC Cabin Septic System Page 3

Figure 3: Interior of Lift Station showing flooded floor. Motors & other electrical components wall mounted

Figure 4: Force main behind RV Pad lift station

Replace Lift Station at RV pads and CCC Cabin Septic System Page 4

Figure 5: Valves outside of the back of the Lift Station shed connected to the lift station pumps

Two houses on Cabin Rd are served by a septic tank and lift station. The two houses are designated 324 and 322 Cabin Rd. The two houses combine for 3 bedrooms. Main septic lines exit the house below grade and tie together at the existing 750 gal septic tank. Historic information lists the drain pipe from the houses to the tank as cast iron pipe. The septic tank has root intrusion. A live oak tree is located approximately 20 ft from the septic tank. A drain line leaves the septic tank and distributes effluent fluids throughout a grassy area. The drain lines have become broken and full of sand. The tank and drainfield are undersized according to modern State requirements for residential wastewater systems. Investigations on site reveal 3in –

4in diameter pvc pipe as drain lines looped together in an area measuring approximately 15 ft wide and 30 ft long and containing 3-4 cross connections in the drainfield.

An abandoned satellite dish approx. 15 inches in diameter is mounted to a 4x4 wooden post beside the septic tank on Cabin Rd.

4.0 SCOPE OF WORK

4.1 Task 1: Replace Lift Station motors, pumps, and electrical components on

Loggerhead Lane:

Replace Lift Station at RV pads and CCC Cabin Septic System Page 5

4.1.1 Remove existing Lift Station mechanical and electrical components.

Existing concrete is to remain in place. Components include the pipes, valves, electrical, floats, pumps, motors, mounts, access hatch, and any moving or stationary supports and components. Disconnect the existing lift station from the electrical service. Disconnect the electrical service and components, including panel, wiring, conduit, etc. back to the electric panel inside the Laundry building. Empty existing lift station of contents.

4.1.2 Provide new lift station components. Provide dual pumps which operate alternately automatically. New package unit above ground lift station shall be Gorman Rupp 6x6 T2 or equivalent.

4.1.2.1 New package unit shall have pumps and motors above

ground and may be mounted on top of the existing slab. The existing slab may be modified/expanded to allow proper installation of the new components. Modifications to the slab and/or shed including concrete of carpentry work are included within this project.

4.1.2.2 New package unit shall provide suction pipes extending into the access hatch. A new hatch cover/lid shall be provided with waterproof seals at joints for the hatch and penetrations including floats, pipes, vents, etc. The hatch opening may be modified to fit the new package unit. Modification of the access opening shall be structurally able to hold minimum 400 pounds point load, fastened and sealed to the concrete tank lid/floor, and is considered part of this project.

4.1.2.3 New lift station shall include two alternating

pumps/motors.

4.1.2.4 New lift station shall be powered with single phase power.

4.1.2.5 New lift station pumps shall be self-priming.

4.1.2.6 New lift station shall be float operated. Pump Control system shall be National Electrical Manufacturers Association

(NEMA) rated.

4.1.2.7 New lift station shall be completely operational and

connect to the existing effluent pipe force main.

4.1.2.8 Provide new electrical connections and alarm for the lift station meeting Building Code and Dare County code. Switches must include manual, off, and automatic function.

4.1.2.9 Provide new wiring from existing electric panel inside the

Laundry building to the lift station. Provide new exterior subpanel and cut off switch for the new lift station. Provide a mounting board consisting of two 4x4 slat treated posts and salt treated 2x6 solid wood boards for plywood, approx. 2 ft x 4 ft to fit electric panel and controls. Electrical installation shall be according to

National Electric Code (NEC) and National Electrical Contractors

Association NECA 1. Exterior panels/boxes shall be NEMA rated weatherproof and corrosion protected rated for exterior use in

Replace Lift Station at RV pads and CCC Cabin Septic System Page 6 corrosive environment. Polycarbonate, Fiberglass, or Stainless steel type 316 enclosures are required. Galvanized or type 304 stainless are not acceptable.

4.1.3 After new lift station is complete, fill with fluid and test pumps to ensure proper operation. Conduct leak test for force main connections. Provide the results of the leak test to the Contracting Officer and Contracting

Officer Representative.

4.1.4 Provide 1 hour on site training for NPS personnel.

4.1.5 Provide operations and maintenance manuals for package unit and alarm system installed.

4.2 Task 2: Replace the septic tank and drainfield at the CCC Cabins near building

324.

4.2.1 Pump out the existing septic tank.

4.2.2 Remove the existing tank completely. Cut existing septic supply lines from the adjacent houses back from the existing tank far enough

(minimum 3 ft) to safely remove the existing tank without damaging the septic lines, and provide room for new tank to be installed and connected.

Cut to a joint or other convenient junction to facilitate tie in of new septic line. Examine existing septic line to note any blockages, sediment build up, etc. Provide photo of existing condition of drain line.

4.2.3 Remove existing top soil and grass from the existing drainfield. Remove existing drainfield lines, distribution box, and related drainpipe coverings, valves, etc.

4.2.4 Replace the existing septic tank with a new septic tank of at least 1,500 gal to serve the two residences. New tank shall include removable and washable effluent filter. Fill new tank prior to covering/backfilling to test for leaks. Provide risers and lids to raise manhole/access lids at least 3 inches above ground level. New lids and risers must be securely mounted to new tank. Provide plastic/fiberglass lids with hinges.

4.2.5 Provide new distribution box and drainfield. Size the drainfield based on

State of NC / Dare County Septic field requirements for residential drainfields and the number of bedrooms in the CCC Cabins being served.

Provide septic pipe from the new tank to the distribution box and new drainfield lines. Drainfield lines may be chamber type infiltration and filter fabric, or traditional perforated pipe and trench. Space the trenches accordingly per State and County policies.

4.3 Task 3: Provide disposal tickets for demolition debris.

4.3.1 Provide ticket from landfill for materials disposed of as part of this project. Provide tickets showing weight and/or volume of materials disposed of in the landfill.

Replace Lift Station at RV pads and CCC Cabin Septic System Page 7

4.3.2 Provide tickets from recycling facility if any material such as wiring, rubble, etc. is diverted from landfill and disposed of at a recycling facility or other location other than the landfill.

NOTES:

1. The contractor is responsible for lockout/tagout procedures while working in the Laundry room electrical panel. Coordinate shutdown of the lift station and laundry room with the

Contracting Officer Representative prior to commencing work. Coordinate down time of the CCC Cabins and their usage of the septic system with the Contracting Officer

Representative prior to commencing work.

2. The Contractor shall submit a task by task work schedule and a schedule of values. The schedule will be made to minimize the down time of the septic system.