BTW, while our water here in the silicon valley is treated with chlorine I get a 0ppm level when testing at my tap. Obviously the level is below the sensitivity of my taylor kit.
Steve,
A quick check on EPAs site gives reference to the Federal Register, 40 CFR Parts 141 and 142. Within that, 141.72 gives the following:
(2) The disinfection system must have either (i) redundant
components, including an auxiliary power supply with automatic start-up
and alarm to ensure that disinfectant application is maintained
continuously while water is being delivered to the distribution system,
or (ii) automatic shut-off of delivery of water to the distribution
system whenever there is less than 0.2 mg/l of residual disinfectant
concentration in the water. If the State determines that automatic shut-
off would cause unreasonable risk to health or interfere with fire
protection, the system
[[Page 446]]
must comply with paragraph (a)(2)(i) of this section.
(3) The residual disinfectant concentration in the water entering
the distribution system, measured as specified in Sec. 141.74 (a)(5)
and (b)(5), cannot be less than 0.2 mg/l for more than 4 hours.
(4)(i) The residual disinfectant concentration in the distribution
system, measured as total chlorine, combined chlorine, or chlorine
dioxide, as specified in Sec. 141.74 (a)(5) and (b)(6), cannot be
undetectable in more than 5 percent of the samples each month, for any
two consecutive months that the system serves water to the public.
There are ways to get around this requirement, but I don't think they would be opted for in most situations. If you do not have any detectable level, then if I were you, I would give a call to the supplier and ask it that is consistent with what they think should be going on.
Let me know if I can help.
Vermonter