New Water Main Disinfection.
New Water Main Disinfection.
(OP)
I am looking for a listing of steps for disinfecting a new water main installation. I work in NJ and would like to find a standard that applies to NJ. I'm okay with the 24hr chlorination period but after flushing the new main after that period and achieving a system level residual is the coliform test taken then or does the main have to sit again?





RE: New Water Main Disinfection.
New Jersey Department of Environmental Protection,
Bureau of Safe Drinking Water
N.J.A.C. 7:10-11.6(d)
good luck
RE: New Water Main Disinfection.
It should apply anywhere in the U.S.
I've not been able yet to find copies of AWWA standards on-line without a subscription; but, you can do a search and get on-line subscriptions.
RE: New Water Main Disinfection.
A: shut it down for another 24hrs, flush again and if the cl2 is okay take the bacti test.
B: Keep flushing until the residual is close to system level and then take a bacti test.
RE: New Water Main Disinfection.
RE: New Water Main Disinfection.
RE: New Water Main Disinfection.
RE: New Water Main Disinfection.
B should work.
The method of chlorinating could have an effect on this. If tablets are used, they may not totally dissolve within the 24 hour period. If that is the case, allowing the line to set an additional period could dissolve the tablets so they can be flushed out.
RE: New Water Main Disinfection.
Standard Specifications for Water and Sewer Main Construction in Illinois
41-2.141 Repetition of Flushing and Testing
Should the initial result in an unsatisfactory bacterial test, the original chlorination procedure shall be repeated by the Contractor until satisfactory results are obtained on successive samples taken at least 24 hours apart.
I believe this is the same as AWWA Standard C651-92.
RE: New Water Main Disinfection.
RE: New Water Main Disinfection.
The engineer tested the residual after sitting 24 hrs and gave the okay to flush and left. I don't know how long they flushed but the residual was over 1ppm (1.10 mg/l)when I sampled it. With that being way over normal system levels it was decided to flush the main longer, increasing the flow. After an hour the residual was at .35 mg/l and decided to take the bacti test then. The test results were all negative. It pissed me off having to do what is the contractors job and the town being too cheap in not having an engineer on-site.