Design Professional’s Specification

Water line disinfection is to be performed by a licensed C-34 pipeline contractor with training in potable water line disinfection, a C-36 plumbing contractor with training in potable water line disinfection, or a D-1 water operator contractor (Water Tech companies) licensed by the state of California with training in potable water line disinfection.

Water lines shall be cleaned by following guide lines provided by the AWWA standard C-651 for water mains and UPC Section 609.9.1-4 with procedures below for building water lines. Use a chemical feed pump & tank for pressurized systems and a water buggy with pump for unpressurized systems.

Disinfection Procedures / 3 Hour Disinfection

(Chemical feed pump method / Building side of the Double Check Valve Assembly)

Clean and disinfect all hot and cold water systems connected to the domestic water system in accordance with AWWA Standard C-651 for water mains and procedures below for building water lines, and as prescribed by the local Building and Health department codes. This procedure shall be performed by a Licensed C-34 or C-36 Contractor trained in the disinfection of water systems or by a state certified Water Operator with a minimum of a D-1 license.

Preliminary Preparation:

Locate the injection point. Install an injection hose bib to the system at a point within 10’-0” of its junction with the water supply line. When the project is complete, with all the fixtures connected and operable and ready for use and when, by test, the system is proved to be free from leaks, it shall be thoroughly flushed by fully opening every outlet and operating every fixture until clear water flows from all of them. Take a Sample, preferably from a drinking faucet, test for Free chlorine content and record it on the work sheet. Use (LR) Low Range Disinfection test strips.) A Normally reading will be 2mg/L or less. This is your “Bench Mark” reading.

Disinfecting Agent:

The chlorine shall be a registered product with Cal-EPA for use in California in potable water lines, such as Bacticide, Cal-EPA Registration No. 37982-20001. Use liquid Sodium Hypochlorite conforming to ANSI/AWWA B300). Fill your tank with water and add the Sodium Hypochlorite until you obtain a reading of 300ppm. Use a High Range Test Strip.

Disinfecting Procedure:

Chemical feed pump method – pressurized system / Connect the chemical pump to the injection hose bib. (If the existing pressure exceeds 60psi use a Backflow & Regulator Injection Assembly for easy injection).

I. With system completely full of water and supply valve open, adjust every faucet of system so that a trickle of water flows from each. Start testing from closest fixture, obtain desired reading, close outlet and move to the next fixture in line. (Repeat) first cold lines then hot lines.

(For electronic faucets, Find the furthest fixture and trickle at a higher rate until you obtain your first reading. Then work backwards.) You may want to remove the supply line from the furthest faucet and replace it with a 3ft. supply line allowing you to trickle into the sink via the angle stop vs. the faucet, until you obtain your first reading.

II. Inject disinfectant until a test at each branch outlet shows a chlorine residual concentration of at least 200 parts per million (ppm). (Use H/R Disinfection test strips.)

III. Close all outlets and valves. Shut down the pump. Close the valve connected to the fresh water supply line. Close the injection hose bib. Maintain condition for 3 hours at 200ppm. Test a couple fixtures after the 3 hours to make sure at least 200ppm remained in the lines. If the strength has dropped below the 200ppm, leave the system charged for a 24 hour test. After 24 hours test strength again. The system must have at least 25ppm remaining or the procedure must be repeated. Flush again and start over, you must have a clog in the lines. (mud, insects?)

IV. When the above procedure has been completed, flush out entire system with fresh water until a test at any outlet shows a residual of not more than 4ppm or the original “Bench Mark” reading taken in the preliminary preparation. (Normally 2mg/L or less. Use L/R Disinfection test strips or a professional chlorine meter. When flushing, pay attention to any special requirements. Never flush highly chlorinated water into storm drains, creeks, rivers or septic tanks! De-chlorinate the discharge water with Ascorbic Acid or use a carbon filter to remove the chlorine. PROTECT THE FISH AND WILDLIFE!

V. Warning signs shall be provided at all outlets while chlorinating the system. (Use signs printed in both English and Spanish). “Do not use water” Chlorination in progress.

VI. Upon completion; chemical and bacteriological tests shall be conducted by a state-certified laboratory and approved by the Mechanical Engineer or AHJ. Copies of the tests shall be submitted to the Architect and all governing authorities. (Use one of the Micro Biologist sample bottles provided from your State Certified Lab.) Keep the sample cool and deliver it to a local independent lab for written results. Deliver copies of written results to owner’s representative.


Water lines shall be cleaned by following guide lines provided by the AWWA standard C-651 for water mains and guide lines provided by DP Disinfection for building water lines.

Disinfection Procedures / 24 Hour Disinfection

The only difference in a 24 hour disinfection vs. a 3 hour disinfection is the strength of the sodium hypochlorite and stand time.

A 24 hour disinfection requires only 50ppm to be pumped into the system and must have at least 25ppm remaining after the 24 hour period where a 3 hour disinfection requires 300ppm to be pumped into the sytem and must have at least 200ppm remaining after the 3 hour period.

Follow the same procedures.