SOW_Ft_Raleigh_MRC_6_pages_.pdf

CAPE HATTERAS NATIONAL SEASHORE

Fort Raleigh

Manteo, North Carolina

STATEMENT OF WORK:

Replace the Septic Tank and Drainfield at the

Ft Raleigh Museum Resource Center

NATIONAL PARK SERVICE

Region 2

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CAPE HATTERAS NATIONAL SEASHORE

Outer Banks Group

Statement of Work

Replace Septic Tank and Drainfield at Ft Raleigh Museum Resource Center

1.0 INTRODUCTION

The National Park Service (NPS) Cape Hatteras National Seashore (CAHA) has a requirement to replace the septic tank and drainfield at the Museum Resource Center (MRC) on Fort Raleigh

National Historic Site (FORA).

2.0 CONSTRUCTION SITE LOCATION

The address for the project site is 1419 Pear Pad Rd Manteo, NC 29754.

3.0 BACKGROUND AND EXISTING CONDITIONS

The MRC at 1419 Pear Pad Rd in Manteo, NC is a storage facility for Artifacts and other resources for the Outer Banks Group as well as office space for cultural resource personnel. The building is a CMU Block structure approximately 44 ft x 70 ft. The building is occupied daily by 3 – 4 personnel. The building includes one restroom with a single toilet and sink as well as an eye wash station at the northeast end of the building. The wastewater is collected in a PVC pipe and drains by gravity toward the east to a pair of septic tanks. Effluent fluids drain into a gravity fed drainfield approximately 90 ft east of the MRC. The drainfield has become covered in vegetation including brush, trees and other rooting plants so that the drainfield no longer functions adequately. The existing septic system is original to the building, construction in circa

1996. The two tanks are between 500 gall and 750 gal each. The system is past its useful life, does not properly drain, and has been encroached by tree and other vegetation roots. Sewage is being pumped periodically from the septic tank to allow limited usage of the MRC. Other utilities in the immediate vicinity of the MRC have been installed and some may have been disconnected. See figures below for vicinity maps of the location.

A chain link fence surrounds the MRC. The area on the east, south, and west side of the MRC has been cleared of trees and vegetation approximately 50 ft away from the building.

The site was examined according to North Carolina Administrative Code Title 15A Chapter 18

Environmental Health Subchapter 18A Sanitation Section .1900 Sewage Treatment and Disposal

Systems. Specifically, the topography, landscape, soil characteristics, soil wetness condition and water table depth, soil depth and restrictive horizons, daily flow rate, and setbacks for the location of tank and drainfield.

Consultation with the Dare County Public Health On Site Water Protection Branch provided helpful information on the soil type in the Ft Raleigh area as a Sandy Loam. A percolation test was not conducted on site due to the sandy nature of the soil. A maximum Long Term

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Acceptance Rate of 0.8 is allowable for the drainfield sizing calculations, depending on the type of drainfield installed.

Figure 1: Existing drainfield and septic tank located behind the MRC at 1419 Pear Pad Rd.

Figure 2: Utility Drawing for MRC and surrounding area.

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4.0 SCOPE OF WORK

Replace the septic system with a new septic system. New septic system shall be installed by a qualified installer according to North Carolina General Statues, 15A NCAC 18A, and the

International Building Code/Plumbing Code.

1. Empty existing septic tank from solids and fluids.

2. Demo existing two concrete septic tanks approx. 750 gal concrete.

3. Demo existing drainfield components:

a. Remove existing drainfield pipe and distribution box (approx. 90 linear ft)

b. Remove approximately 80 ft of drain pipe from the cleanout located on the east side of the MRC to the existing septic tank.

c. Backfill tank and trenches with soil from new excavations.

4. Provide new 1,000 gallon concrete septic tank. Locate new tank on the southeast side of the MRC in the location shown in figure 3 below, approximately 25 ft from the MRC.

(See below sketch of proposed layout of new drainfield).

a. Connect the existing drain line from the cleanout on the east side of the MRC to the new septic tank, approximately 50 ft. Use schedule 40 PVC or approved equal material.

b. Install a new cleanout at the intersection of bends in new septic pipe.

c. Provide properly sealed joints and connections from the existing drain pipes to new sections of pipe which seal to the new septic tank. Use schedule 40 PVC or approved equal material.

5. The new 1,000 gal septic tank shall include at a minimum:

a. Water tight joints

b. Concrete baffles

c. Effluent filter

d. Access opening less than 18 inches from the end of the tank to visually see the inflow pipe.

e. Adequate opening less than 12 inches from the effluent filter to be able to visually see and physically reach the effluent filter without entering the tank.

f. Access opening to visually see the concrete baffle.

g. Provide Concrete lids on the concrete septic tank with type 316 stainless steel handles. Concrete tanks with risers do not require concrete lids with stainless handles as long as the HDPE risers and riser lids meet State requirements for lids.

h. HDPE risers and riser lids which extend a minimum of 12 inches above grade.

Plastic riser lids shall be locking, mechanically sealed, or above 65 lbs weight

6. Provide new distribution tank and infiltrator drainfield. Drainfield shall be a minimum of

150 LF of new drain lines.

a. Provide 36 in wide infiltrator type septic drainfield sections similar to Infiltrator

Water Technologies Quick4 Equalizer 36 which provide a minimum overall length of 150 LF of infiltration drain lines. Low profile or Standard profile for lower capacity is not acceptable.

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b. Install chambers according to manufacturer’s installation instructions. Provide filter cloth above infiltrator sections according to the manufacturer’s instructions for the brand name utilized.

7. Provide seeding to the disturbed area, including demolished drainfield, new drainfield, and ruts or other disturbance created by construction. Continue to water the grass until

75% of the area has seeded and growing.

a. Seed shall be suitable for the following:

i. Mostly sun location

ii. Residential lawn

iii. Mowing operations with hand operated push or riding mowers

iv. Sandy soils

v. Septic Field coverage (roots that do not grow deeper than 24 inches)

vi. No weeds (dandelion, bahai, pennywort)

vii. No exotic species.

b. Broadcast or Hydroseed. Add a cover crop of grain rye at 30 lbs/acre. Rake broadcasted seed mix into the soil and saturate with water 2 – 3 times per day for

7 days, or until 75% of the area has seeds germinated and growing at least 1 inch high. Hydroseeded area may be observed for 7 days or until 75% of the area has growing seeds. If after 7 days, the area is less than 75% covered with new growth, overseed again and water 2-3 times per day until 75% of the ground is covered with growth.

Figure 3: Proposed layout of new MRC Septic System on Ft Raleigh

NOTES:

1. The Contractor must verify all existing conditions, measurements, and equipment.

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2. The Contractor must track demolition debris which are removed/recycled and provide NPS with receipts showing the weight and volume and type of material removed/recycled as part of this project.

3. No construction debris will be allowed to be left on premises. All public areas will remain clean and passible during normal business hours. During business hours, the contractor will ensure that no music is playing in the work areas and no foul language will be tolerated during or after business hours. Work on this project will be accomplished within the hours of 7:00 AM to 5:00 PM Monday thru Friday.

5.0 GOVERNMENT FURNISHED PROPERTY

1. No Government property, materials, or equipment will be provided. Water and electricity on the exterior of the existing MRC is available for Contractor use during this project. Contractor is responsible for lockout/tagout. Contractor is responsible for cleaning up site daily, and for repairing ruts created in grass areas.

Ruts shall be filled in or raked smooth before final acceptance of the project.

6.0 SUBMITTALS

1. Work schedule: delineating the various stages of work by phase (milestones) prior to the preconstruction conference.

2. Safety Plan/Accident Prevention Plan prior to the preconstruction conference.

3. Product Data

a. Septic Tank

b. Septic Chambers

c. Connections, Fittings, Wyes, PVC pipe

d. Manhole Riser Data

e. Fill Material

f. Seed Mix

g. Operation and Maintenance Manuals

4. Product Samples. The Contractor shall submit written documentation or color/product samples for materials identified in the Scope of Work for selection by the CO/COR.

a. Fill Material

b. Seed Mix

5. As-built drawing. Provide a to-scale surveyed drawing of the new septic system showing the accurate location of the new tank, distribution box, and drainlines. Include the locations relative to the existing fencelines, buildings, water lines, electric lines, and pavement.