1 SOW 8 4 20.pdf

Correct Deficiencies of Ft Raleigh and Frisco Water Systems Page 1

CAPE HATTERAS NATIONAL SEASHORE

Outer Banks Group

Statement of Work

Correct Deficiencies of Ft Raleigh and Frisco Water Systems

1.0 INTRODUCTION

The National Park Service (NPS) Cape Hatteras National Seashore (CAHA) has a requirement to correct deficiencies found at the Ft Raleigh Water Treatment Plant (WTP) in Manteo, NC, and the Frisco Campground WTP in Frisco, NC.

2.0 BACKGROUND AND EXISTING CONDITIONS

The Ft Raleigh WTP is located off of Pier Pad Rd on Ft Raleigh National Historic Site. The water plant was constructed in the 1960s and has been upgraded several times over the years as development at Ft Raleigh has occurred. The water system consists of water supply and water treatment building and serves the water distribution system at Ft Raleigh. Two shallow wells (approx. 42-45 ft deep) provide raw water through a pump house receiving a minimal chlorine dose and into a 100,000 gallon ground water storage tank. The water feeds back into the treatment building through two pumps and into a 3,000 gal hydropneumatic (pressurization) tank. The raw water is filtered and chemically treated with a 35 gallon chlorine dosing tank.

The pressurized and treated water is pumped through an 8 in main distribution line to Ft Raleigh buildings serving fire hydrants and domestic water. Two fire booster pumps are connected in parallel to feed the Ft Raleigh water distribution system in the event of a large water need for the system. A separate room within the treatment building houses six 50 gal back up bladder tanks which can supply pressurized water to Ft Raleigh in the event of maintenance needs, or system pump problems, etc. The Ft Raleigh water storage tank was last cleaned according to records in 2012.

The Frisco Campground is located at the end of Billy Mitchell Rd in Frisco, NC. The water treatment plant is accessed by an unpaved road at the east end of the campground. The Frisco CG WTP is served by a water generation, storage, treatment, and distribution system. The Frisco Campground WTP was placed into service in 1983 and consists of three wells, a 200,000 gal raw water storage tank, a water treatment facility with filters and chlorine dosing tanks, 2 pumps which send potable water through a 4 inch PVC water distribution line to the Frisco Campground comfort stations and showers. The wells must be operated manually to fill the water storage tank. The 4 water bladders provide pressure to the distribution system. The Frisco Water storage tank was cleaned on the interior according to records in 2012.

A copy of the most recent State of North Carolina Department of Environmental Quality (NCDEQ) inspection reports for Ft Raleigh and Frisco Campground WTPs are available for viewing

Correct Deficiencies of Ft Raleigh and Frisco Water Systems Page 2

3.0 MAJOR COMPONENTS

1. Coordinate with the local Fire department to inform them of the maintenance activities and the duration that the water tank will be off-line and unavailable for use and support of fire hydrants.

At the Ft Raleigh WTP, the contractor shall:

2. Coordinate with Ft Raleigh maintenance personnel to switch the Ft Raleigh water system to the main pressurization system to the back up water bladders.

3. Empty the 100,000 gal tank completely.

4. Clean and refill the interior of the tank according to American Water Works Association

(AWWA). There are several AWWA-approved ways to disinfect a storage tank after you take it out of service for cleaning, inspection, or repairs. Submit the AWWA approved method for cleaning for Contracting Officer approval, or use the following method taken from the AWWA. Any variation from the following must be submitted in writing before performing work and approved by the Contracting Officer.

a) Use a high-pressure water jet, sweep, scrub, or other methods to clean wall and floor surfaces thoroughly. Flush all water and dirt from the tank. Vacuum remaining sediment/dirt/solids/suspended solids from the tank.

b) Inspect interior tank floor, walls and ceiling for leaks cracks, loose paint, rust, or other signs of deterioration. Provide pictures of each location and caption of the deterioration.

c) AWWA Standard C-652 Chlorination Method 3. Broom-clean the bottom of the tank.

Then begin to add potable water until the tank is about 5 percent full. Next, add the appropriate quantity of chlorine directly into this water. The amount of chlorine you add should result in a free chlorine residual between 2.5 and 3.0 parts per million when the tank is completely full. If you use regular household chlorine bleach (6 percent chlorine by weight), add 1 gallon for every 20,000 gallons of tank capacity.

d) After adding chlorine, fill the remaining 95 percent of the tank with potable water and wait 24 hours. At the end of 24 hours, measure the free chlorine residual of the water inside the tank. If the water in the tank has a free chlorine residual of at least 2 parts per million, then collect a coliform sample from the tank. If the coliform sample is satisfactory, then you may place the reservoir directly back into service. If the coliform sample shows the presence of coliform, contact your regional office for instruction on further disinfection and testing.

5. Pressure wash the outside of the tank.

6. Inspect the outside of the tank for cracks, leaks, rust, and visible signs of deterioration.

Photograph and document, the findings of the inspection.

a) Seal concrete leaks with 2 part epoxy waterproof concrete repair using injection method for full depth up to 90 linear ft of 1/32 inch wide and 4 inch deep cracks.

7. Recoat the exterior of the tank. Use exterior paint for concrete water storage tanks meeting

AWWA recommendations. Provide White paint with semi-gloss finish. Prepare the surface to be painted according to paint manufacturer’s instructions. Submit product data and surface preparation instructions prior to emptying the tank. Protect observation ports, tank water level measurement devices, and other appurtenances.

Correct Deficiencies of Ft Raleigh and Frisco Water Systems Page 3

8. Empty the 3,000 gal pressurization tank. Remove sediment, lime, rust, sludge, etc from within the tank. Wash the interior of the tank with (cleaning agent). Remove cleaning agents and purge tank of any residue from the cleaning operation.

9. Pressure wash the 3,000 gal pressurization tank. Inspect the 3,000 gal tank for rust, leaks, or deterioration.

10. Disconnection and reconnection of plumbing items necessary for a complete and usable project is included in this project.

At the Frisco Campground WTP, the contactor shall:

11. Coordinate with the Buxton maintenance personnel to turn off or switch the Frisco water system to the main pressurization system to the back up water bladders.

12. Empty the 200,000 gal tank completely.

13. Clean and refill the interior of the tank according to American Water Works Association

(AWWA). There are several AWWA-approved ways to disinfect a storage tank after you take it out of service for cleaning, inspection, or repairs. Submit the AWWA approved method for cleaning for Contracting Officer approval, or use the following method taken from the AWWA.

a) Use a high-pressure water jet, sweep, scrub, or other methods to clean wall and floor surfaces thoroughly. Flush all water and dirt from the tank. Vacuum remaining sediment/dirt/solids/suspended solids from the tank.

b) Inspect interior tank floor, walls and ceiling for leaks cracks, loose paint, rust, or other signs of deterioration. Provide pictures of each location and caption of the deterioration.

c) AWWA Standard C-652 Chlorination Method 3. Broom-clean the bottom of the tank.

Then begin to add potable water until the tank is about 5 percent full. Next, add the appropriate quantity of chlorine directly into this water. The amount of chlorine you add should result in a free chlorine residual between 2.5 and 3.0 parts per million when the tank is completely full. If you use regular household chlorine bleach (6 percent chlorine by weight), add 1 gallon for every 20,000 gallons of tank capacity.

d) After adding chlorine, fill the remaining 95 percent of the tank with potable water and wait 24 hours. At the end of 24 hours, measure the free chlorine residual of the water inside the tank. If the water in the tank has a free chlorine residual of at least 2 parts per million, then collect a coliform sample from the tank. If the coliform sample is satisfactory, then you may place the reservoir directly back into service. If the coliform sample shows the presence of coliform, contact your regional office for instruction on further disinfection and testing.

14. Pressure wash the outside of the tank.

15. Inspect the outside of the tank for cracks, leaks, rust, and visible signs of deterioration.

Photograph and document, the findings of the inspection.

a) Seal concrete leaks with 2 part epoxy waterproof concrete repair using injection method for full depth up to 230 linear ft of 1/32 inch wide and 4 inch deep cracks.

16. Recoat the exterior of the tank. Use exterior paint for concrete water storage tanks meeting

AWWA recommendations. Provide White paint with semi-gloss finish. Prepare the surface to be painted according to paint manufacturer’s instructions. Submit product data and

Correct Deficiencies of Ft Raleigh and Frisco Water Systems Page 4 surface preparation instructions prior to emptying the tank. Protect observation ports, tank water level measurement devices, and other appurtenances.

17. Disconnection and reconnection of plumbing items necessary for a complete and usable project is included in this project.

OPTION 1: Recoat the interior of the Ft Raleigh Water Tank. After washing and inspecting the 100,000 gal water storage tank, and prior to refilling the tank, recoat the interior of the tank.

18. Re-coat the inside of the tank. Follow American National Standards Institute (ANSI) /

National Sanitation Foundation (NSF) 61 requirements for painting of interior and exterior of concrete water storage tanks. Use NSF 61 Certified Products only. Submit the paint system and application instructions, including surface preparation, number of layers, materials, drying time, and adherence to ANSI/NSF standards.

OPTION 2: Recoat the interior of the Frisco Water Tank. After washing and inspecting the 200,000 gal water storage tank, and prior to refilling the tank, recoat the interior of the tank.

19. Re-coat the inside of the tank. Follow American National Standards Institute (ANSI) /

National Sanitation Foundation (NSF) 61 requirements for painting of interior and exterior of concrete water storage tanks. Use NSF 61 Certified Products only. Submit the paint system and application instructions, including surface preparation, number of layers, materials, drying time, and adherence to ANSI/NSF standards.

Figure 1: Ft Raleigh Water Plant Location

Correct Deficiencies of Ft Raleigh and Frisco Water Systems Page 5

Figure 2: Water Plant Building showing pressurization tank which extends partially out the back of the building

Correct Deficiencies of Ft Raleigh and Frisco Water Systems Page 6

Figure 3: Ft Raleigh 100,000 gallon water tank

Correct Deficiencies of Ft Raleigh and Frisco Water Systems Page 7

Figure 4: Frisco Campground Water Treat Plant

Figure 5: Frisco CG Water Treatment Building and Water Storage Plant