A06_-_140L1721Q0025-Section_02512.pdf

DISINFECTION OF WATER DISTRIBUTION

State Bridge Water System [02/21]

02512 - 1

SECTION 02512

PART 1: GENERAL

1.1 SUMMARY

A. Section Includes: The disinfection of the water system.

1.2 SUBMITTALS

A. General: Submittals shall be according to Section 01009 - General Information and Requirements.

B. Sample Results: Submit 1 electronic copy for each of the laboratory’s water sample results. Submit within 24 hours of getting the results from the laboratory.

C. Testing Laboratory: The contractor shall submit the name, phone number, and address of the laboratory to be used for testing the water samples.

Laboratory shall be certified with the CDPHE.

1. Contractor shall be responsible for payment to laboratory for analysis of all water samples, however Government personnel shall delivery samples to lab after contractor sample collection as stated below in 1.3, A.

1.3 PROJECT RECORD DOCUMENTS

A. Water Samples: After disinfection of the water system, fill the system with hauled potable water. The contractor shall take 2 water samples to test for total coliform bacteria. If applicable, repeat disinfection and sampling until system tests negative for total coliform bacteria. Samples shall be taken in sealed containers supplied by a CDPHE certified testing laboratory.

Location for water sampling shall be from the frost-free hydrant. Samples shall be taken in the presence of the Contracting Officers Representative and/or approved Government personnel. After collection of samples, supply samples, including container or cooler as recommended by laboratory for transport of samples, to government representative for delivery to approved laboratory for testing. Samples shall be collected as instructed by the laboratory, and at a minimum include the following:

1. Date issued, project name, and testing laboratory name, address, and telephone number.

2. Time and date of water sample collection.

3. Name of person collecting samples.

4. Test location.

PART 2: PRODUCTS

2.1 MATERIALS

A. Sodium Hypochlorite (Bleach): Shall be new, NSF certified, unscented bleach, minimum 6.25% Sodium Hypochlorite according to AWWA B 300.

State Bridge Water System [02/21]

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B. Hauled Potable Water: Per Section 02514.

PART 3: EXECUTION

3.1 APPLICATION

A. Disinfection: Disinfect the water distribution system as follows:

1. Verify valve immediately downstream of tank is closed.

2. While tank is being filled with hauled potable water, add 2 gallons of unscented bleach, fill tank until full. Allow chlorinated water to remain in tank for a minimum of 2 hours.

3. Verify frost-free hydrant is in the closed position, and all drain valves are closed. Open curb valve immediately downstream of tank to fill distribution system with chlorinated water. Open hydrant until chlorinated water flows from hydrant, then close and lock the hydrant.

4. Allow disinfectant to remain in the system for approximately 4 hours.

5. NOTE: While draining system, DO NOT ALLOW chlorinated water to flow directly into the Colorado River. After disinfectant has been in the system for 4 hours, open the tank drain valve approximately 1/4 open to slowly empty the chlorinated water from tank. Monitor discharge from tank and reduce flow or stop flow if water starts flowing freely over the ground surface and towards the river. Once tank is empty, close the tank drain valve and empty the majority of the distribution system by attaching a clean hose, minimum 50’ length, to the hydrant and open hydrant. Direct flow from hydrant evenly through hose and uniformly onto vegetation and away from the river. Once water stops flowing from hydrant, open drain valve near hydrant and drain remaining chlorinated water from system. Monitor flow from drain near hydrant and prevent discharge from contacting the river.

B. Water Sampling: After disinfection of the water system is complete, fill the tank and distribution system with potable water as described in Section 02514. Take water samples as described above in 1.03, A. Repeat disinfection if bacterial samples test positive.

PART 4: MEASUREMENT AND PAYMENT

4.1 METHOD OF MEASUREMENT

A. Units: The work described in this section will not be measured for payment.

4.2 BASIS OF PAYMENT

A. Payment: No direct payment for the work described under this section will be made. Consideration for this item shall be included in the bid price for other items of the Contract.

END OF SECTION