Current through September 18, 2024
Authority: IC 13-13-5; IC 13-14-8; IC 13-14-9; IC 13-15-1-2;
IC 13-15-2-1; IC 13-18-3
Affected: IC 13-11-2; IC 13-18-4
Sec. 6.
(a)
Disinfection is required of all sanitary wastewater discharges on an annual
basis for the period of April 1 through October 31 except multicelled waste
stabilization ponds that are:
(1) adequately
designed and operated;
(2) not
either hydraulically or organically overloaded; and
(3) in compliance with the provisions of
section 3(c) of this rule.
(b) Disinfection is not required and is not
expected to be practiced on an annual basis for the period of November 1
through March 31, except as necessary to comply with one (1) or more of the
following:
(1) ORSANCO requirements (for
discharges directly to the Ohio River).
(2) The requirements of other states for
interstate waters.
(3) The
provision of section 4(c) of this rule.
In cases where chlorination must be practiced during this
period, for example, to maintain sand filters, the maximum effluent limitation
and monitoring requirements for chlorine remain in effect.
(c) The following are requirements
for facilities using chlorine or other halogenated compounds as a disinfectant:
(1) For those sanitary wastewater dischargers
designated as minor facilities (generally those with a population equivalent
(PE) of less than ten thousand (10,000)), the following requirements must be
met:
(A) Residual chlorine concentration
after disinfection (but prior to dechlorination) is to be maintained at a
minimum of five-tenths (0.5) milligram per liter.
(B) The final effluent must comply with
subsection (e).
(2) For
those sanitary wastewater dischargers designated as major facilities (those
with a PE of ten thousand (10,000) or greater), the following requirements must
be met:
(A) No minimum residual chlorine
limitation applies.
(B) The final
effluent must comply with subsection (e).
(3) Dechlorination is to be practiced for
all:
(A) sanitary wastewater discharges using
chlorine or bromine compounds as a disinfectant; or
(B) filter or other equipment maintenance at
any time; so that the concentration of total residual chlorine (TRC) or, where
bromine is used, TRO in the final effluent does not exceed water quality-based
effluent limitations. If these water quality-based limitations are below the
LOQ, compliance with the water quality-based effluent limitations will be
determined using the applicable procedures contained under
327
IAC 5-2-11.1 or
327
IAC 5-2-11.6.
(d) Facilities using a disinfectant other
than chlorine or other halogen compounds shall ensure that the final effluent
complies with subsection (e) during the applicable recreation season as
indicated in the facility's NPDES permit.
(e) Sanitary wastewater dischargers shall
ensure the following:
(1) The concentration
of E. coli in the undiluted discharge does not exceed one hundred twenty-five
(125) cfu or MPN per one hundred (100) milliliters as a geometric mean of the
effluent samples taken in a calendar month.
(2) Not more than ten percent (10%) of all
samples when not less than ten (10) samples are taken and analyzed for E. coli
in a calendar month exceed two hundred thirty-five (235) cfu or MPN per one
hundred (100) milliliters as a daily maximum. Under this subdivision, the
calculation of ten percent (10%) of the samples taken shall be limited to the
lowest whole number result.
