Sec. 8.5.
(a)
Effective June 29, 1993, a public water system that uses a surface water source
must provide filtration in accordance with this section.
(b) A public water system that uses a ground
water source under the direct influence of surface water shall provide
filtration in accordance with this section beginning eighteen (18) months after
the commissioner determines that it is under the direct influence of surface
water from the date specified in section 8.2 of this rule.
(c) A public water system that uses a surface
water source or a ground water source under the direct influence of surface
water must provide treatment consisting of both disinfection, as specified in
section 8.6 of this rule, and filtration treatment. Filtration treatment shall
be done by one (1) of the following techniques, and the turbidity level of
representative samples of a system's filtered water, regardless of filtration
technique used, shall at no time exceed five (5) nephelometric turbidity units
(NTU) in any given sample, measured as specified in section 8.7 of this rule:
(1) For systems using conventional filtration
or direct filtration, the turbidity level of representative samples of a
system's filtered water must be less than or equal to one-half (0.5) NTU in at
least ninety-five percent (95%) of the total number of measurements taken each
month, measured as specified in sections 8.7(4) and 8.8(b) of this rule, except
that if the commissioner determines that the system is capable of achieving at
least ninety-nine and nine-tenths percent (99.9%) removal or inactivation, or
both, of Giardia lamblia cysts at some turbidity level higher than one-half
(0.5) NTU in at least ninety-five percent (95%) of the total number of
measurements taken each month, the commissioner may substitute this higher
turbidity limit for that system. However, in no case may the commissioner
approve a turbidity limit that allows more than one (1) NTU in more than five
percent (5%) of the samples taken each month, measured as specified in sections
8.7(4) and 8.8(b) of this rule. Upon the effective date of this rule, systems
serving a population of:
(A) at least ten
thousand (10,000) individuals; and
(B) beginning January 1, 2005, fewer than ten
thousand (10,000) individuals;
shall meet the turbidity requirements in
327 IAC
8-2.6-3.
(2) For systems using slow sand filtration,
the turbidity level of representative samples of a system's filtered water must
be less than or equal to one (1) NTU in at least ninety-five percent (95%) of
the measurements taken each month, measured as specified in sections 8.7(4) and
8.8(b) of this rule, except where the commissioner determines that there is no
significant interference with disinfection at a higher turbidity
level.
(3) For systems using
diatomaceous earth filtration, the turbidity level of representative samples of
a public water system's filtered water must be less than or equal to one (1)
NTU in at least ninety-five percent (95%) of the measurements taken each month,
measured as specified in sections 8.7(4) and 8.8(b) of this rule.
(4) A public water system may use a
filtration technology not listed in this subsection if it demonstrates to the
commissioner, using pilot plant studies or other means, that the alternative
filtration technology, in combination with disinfection treatment that meets
section 8.6 of this rule, consistently achieves ninety-nine and nine-tenths
percent (99.9%) removal or inactivation, or both, of Giardia lamblia cysts and
ninety-nine and ninety-nine hundredths percent (99.99%) removal or
inactivation, or both, of viruses. For a system that makes this demonstration,
this subsection applies. Upon the effective date of this rule, systems serving
a population of:
(A) at least ten thousand
(10,000) individuals; and
(B)
beginning January 1, 2005, fewer than ten thousand (10,000) individuals;
shall meet the requirements for other filtration technologies
in
327 IAC
8-2.6-3.
(d) During plant operation, each public water
system subject to this section shall be operated only by personnel who have
been certified by the commissioner under 327 IAC 8-11 through 327 IAC
8-12.
(e) In addition to complying
with requirements in this section, systems serving a population of:
(1) at least ten thousand (10,000)
individuals; and
(2) beginning
January 1, 2005, fewer than ten thousand (10,000) individuals;
shall also comply with the requirements in 327 IAC
8-2.6.
