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SECTION 33 01 10

DISINFECTION OF POTABLE WATER TANK

PART 1 - GENERAL

1.1 Description

A. This Section includes disinfection and VOC (Volatile Organic Compounds) testing of steel water storage tank. See Section 33 13 00 for disinfection of piping.

1.2 Related Work

A. Section 01 10 01 Summary of Work and Sequence of Construction B. Section 01 22 00 Unit Prices C. Section 01 33 00 Submittal Procedures D. Section 09 97 13 Riveted Steel Tank Coating and Painting

1.3 References

A. AWWA C651 - Standard for Disinfection Water Mains B. AWWA C652 - Standard for Disinfection of Water Storage Facilities

1.4 Work by Owner

A. The Owner shall furnish water for the initial filling of the tank to operating capacity after the disinfection of the tank and testing of the water samples. Contractor shall submit for disinfection procedure plan for approval prior to coordinate with LBUD, not less than seven

(7) calendar days prior to the start of work.

B. The Contractor shall pay for all water for subsequent disinfection and testing of the water samples.

C. The Contractor shall obtain water samples and send them to a laboratory, approved by the Owner, for testing.

1.5 Unit Prices

A. Refer to Section 01 22 00 for measurement and payment clauses for disinfecting of potable water tanks.

PART 2 - PRODUCTS

2.1 Acceptable Manufacturers

A. Acceptable Manufacturers and testing agencies include:

ITEM MANUFACTURER MANUFACTURER LOCATION

Chlorination and Testing Contractor

Aqua Backflow Riverside, CA 909 598-7251 Mattchlor, Inc. El Monte, CA 626 443-5034 Morr-is Tested Yorba Linda, CA 714 979-1573 Southwest Chlorination, Inc. Agoura Hills, CA 818 707-4437 Accepted equal

Chlorine Residual Test Kits

Hach Company Chemical Division Loveland CO 800 227-4224 Orbeco-Hellige Sarasota, FL 800 922-6410 Accepted equal

Bacteriological Testing Laboratory

Advanced Technology Laboratories Signal Hill, CA 562 989-4045 Eurofins Eaton Analytical Monrovia, CA 626 386-1100 Silliker Laboratories, Inc. Cypress, CA 714-226-0000 Weck Laboratories, Inc. City of Industry, CA 626-336-2139 Accepted equal

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2.1 Disinfection Chemicals

A. Chemicals: AWWA B300, Calcium Hypochlorite (Dry) or Sodium Hypochlorite (Solution) or

AWWA B301, Liquid Chlorine Solution.

B. Materials for disinfection of the tank shall be as listed in Section 4.2: Forms of Chlorine for

Disinfection of AWWA 652-11 or most current.

PART 3 - EXECUTION

3.1 Disinfection of Interior Surfaces of Tank

A. Disinfect interior surfaces of tank in the presence of the Engineer, in conformance to AWWA

Standard C652 Section 4.3.2 Chlorination Method 2 as modified herein:

1. The Contractor may only perform the disinfection on the interior reservoir surfaces Monday through Wednesday and all disinfection work must be completed by 10:00 am Wednesday. Contractor shall limit Tank shutdown for disinfection to a maximum of 10 (ten) calendar days.

2. Disinfect after completion and acceptance by Owner of all interior recoating and curing of coating as required in Section 09 97 13 Steel Tank Coating and Painting.

3. Prior to disinfecting, clean the complete interior with an approved cleaner or detergent applied via high-pressure method. If deemed necessary by Owner’s Representative because of contaminants remaining on surfaces, scrub immersed areas with a brush or similar implement, which will apply force and pressure to the surface to completely remove residual solvents and other surface contaminants.

4. Contractor shall coordinate with LBUD to purge all tank piping to remove stagnate water and any debris trapped in the line prior to disinfecting the interior of the tank.

5. Rinse the cleaned surfaces with clean water. Thoroughly flush residual water and contamination removed during washing process from tank. Obtain approval of Owner prior to draining any residual water to waste.

6. After completion of cleaning cycles as noted above, jet wash all interior surfaces with a chlorine or chloramine solution having a content of 200 PPM. Drain chlorine or chloramine solution, which accumulates on the bottom to waste. No super chlorinated water may be drained. Contractor must provide proper dechlorination method and test for chlorine residual of 0 at the drain location to meet LBUD discharge permit requirements. Rinsing with clean water is not required unless directed by Owner’s Representative.

a. Contractor shall furnish and install new gaskets and bolts for the manhole and seal-up the tank.

7. Once the tank has been completely filled, the tank will be isolated from the water system and the Contractor will take a Bac-T test. The Contractor will be responsible for all costs associated with re-chlorinating and re-filling of the tank as described above until the Bac-T tests are negative.

8. Comply with all applicable permit and regulation requirements in conformance to AWWA Standard C655 concerning the discharge of water from the work site. Ensure that the requirements of the NPDES General Discharge Permit and City’s BMP’s are followed, that appropriate filtering or settling tanks and/or equipment is utilized, and that de-chlorination of water occurs prior to discharge from the job site.

3.2 Testing for Volatile Organic Compounds (VOC’s)

A. To monitor the presence of VOC’s leached into the water from the coating process, the following procedure shall be utilized:

1. After satisfactory curing, the tank shall be filled by the Owner in accordance with standard filling procedures. Water shall then be retained for a period of five days.

2. On the sixth day following completion of filling of tank, Contractor will remove samples of water, in accordance with latest SWRCB Division of Drinking Water memoranda. Samples will then be forwarded by Contractor to an approved test laboratory to determine presence of VOC’s.

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a. The Contractor shall have an LBUD approved laboratory collect VOC sample and perform analysis to determine the presence of VOC’s. The lab shall submit a written report to LBUD for the analysis performed.

3. After testing of samples, results must show levels of leached organics to be in accordance with levels established by the SWRCB Division of Drinking Water for various VOC’s.

4. If levels of leached organics exceed those acceptable to the SWRCB Division of Drinking Water, drain, flush, and refill the tank and retest at the Contractor’s expense. Failure of the tanks to attain levels acceptable to the SWRCB Division of Drinking Water shall be the responsibility of the Contractor and remedial measures to attain such levels shall be at its sole expense.

5. If leached organics produce any taste and odor objectionable to consumers of the water from the tanks, drain, re-clean, flush, refill and retest at the Contractor’s expense. Failure of the tank to be taste and odor-free shall be the responsibility of the Contractor and remedial measures to attain such a condition shall be at its sole expense.

3.3 Field Quality Control

A. All laboratory reports for disinfection testing shall be legible and include the following information:

1. Sample Site

2. Sample Date

3. Sample Test

4. Chlorine Residual

5. Temperature

6. Sampled by in legible writing

7. Relinquished By, Date and Time in legible writing

8. Received By, Date and Time in legible writing

9. Received Temperature

10. Received on Ice (Yes/No)

11. Analysis Date and Time

12. Analyst Name

13. Notes pertaining to Sample

END OF SECTION