Current through Register Vol. 48, No. 38, September 20, 2024
a)
Following completion of the initial round of source water monitoring required
under Section
611.1001(a),
a filtered system supplier must calculate an initial Cryptosporidium bin
concentration for each plant for which monitoring was required. Calculation of
the bin concentration must use the Cryptosporidium results reported under
Section
611.1001(a)
and must follow the appropriate of the procedures set forth in subsection
(b).
b) Bin Concentration
Calculation Procedures
1) For a supplier that
collects a total of at least 48 samples, the bin concentration is equal to the
arithmetic mean of all sample concentrations.
2) For a supplier that collects a total of at
least 24 samples, but not more than 47 samples, the bin concentration is equal
to the highest arithmetic mean of all sample concentrations in any 12
consecutive months during which Cryptosporidium samples were
collected.
3) For a supplier that
serves fewer than 10,000 people and which monitors for Cryptosporidium for only
one year (i.e., collect 24 samples in 12 months), the bin concentration is
equal to the arithmetic mean of all sample concentrations.
4) For a supplier with plants operating only
part of the year that monitors fewer than 12 months per year under Section
611.1001(e),
the bin concentration is equal to the highest arithmetic mean of all sample
concentrations during any year of Cryptosporidium monitoring.
5) If the monthly Cryptosporidium sampling
frequency varies, a supplier must first calculate a monthly average for each
month of monitoring. A supplier must then use these monthly average
concentrations, rather than individual sample concentrations, in the applicable
calculation for bin classification in subsections (b)(1) through
(b)(4).
c) A filtered
system supplier must determine its initial bin classification according to
subsections (c)(1) through (c)(5), subject to the limitations of subsection
(c)(6), and using the Cryptosporidium bin concentration calculated under
subsections (a) and (b).
1) For a supplier
that is required to monitor for Cryptosporidium under Section
611.1001
and which has a Cryptosporidium bin concentration of less than 0.075 oocysts/l,
the bin classification is Bin 1.
2)
For a supplier that is required to monitor for Cryptosporidium under Section
611.1001
and which has a Cryptosporidium bin concentration of 0.075 oocysts/l or more,
but less than 1.0 oocysts/l, the bin classification is Bin 2.
3) For a supplier that is required to monitor
for Cryptosporidium under Section
611.1001
and which has a Cryptosporidium bin concentration of 1.0 oocysts/l or more, but
less than 3.0 oocysts/l, the bin classification is Bin 3.
4) For a supplier that is required to monitor
for Cryptosporidium under Section
611.1001
and which has a Cryptosporidium bin concentration of 3.0 oocysts/l or more, the
bin classification is Bin 4.
5) For
a supplier that that serves fewer than 10,000 people and which is not required
to monitor for Cryptosporidium under Section
611.1001(a)(4),
the bin classification is Bin 1.
6)
The Cryptosporidium concentration is based on the applicable of the
calculations set forth in subsection (a) or (d).
d) Following completion of the second round
of source water monitoring required under Section
611.1001(b),
a filtered system supplier must recalculate its Cryptosporidium bin
concentration using the Cryptosporidium results reported under Section
611.1001(b)
and following the applicable of the procedures set forth in subsections (b)(1)
through (b)(4). A supplier must then redetermine its bin classification using
this bin concentration and subsection (c).
e) Reporting the Bin Classification
1) A filtered system supplier must report its
initial bin classification under subsection (c) to the Agency for approval no
later than six months after the supplier is required to complete initial source
water monitoring based on the applicable schedule set forth in Section
611.1001(c).
2) A supplier must report its bin
classification under subsection (d) to the Agency for approval no later than
six months after the supplier is required to complete the second round of
source water monitoring based on the applicable schedule set forth in Section
611.1001(c).
3) The bin classification report to the
Agency must include a summary of source water monitoring data and the
calculation procedure used to determine bin classification.
f) A failure to comply with the conditions of
subsection (e) is a violation of the treatment technique requirement.
BOARD NOTE: Derived from
40 CFR
141.710.
