Current through Register Vol. 48, No. 38, September 20, 2024
a) Initial Round of
Source Water Monitoring. A supplier must conduct the following monitoring on
the schedule in subsection (c), unless it meets the monitoring exemption
criteria in subsection (d).
1) A filtered
system supplier serving 10,000 or more people must sample its source water for
Cryptosporidium, E. coli, and turbidity at least monthly for 24
months.
2) An unfiltered system
supplier serving 10,000 or more people must sample its source water for
Cryptosporidium at least monthly for 24 months.
3) Smaller System Suppliers Monitoring for E.
coli
A) A filtered system supplier serving
fewer than 10,000 people must sample its source water for E. coli at least once
every two weeks for 12 months.
B) A
filtered system supplier serving fewer than 10,000 people may avoid E. coli
monitoring if the system notifies the Agency that it will monitor for
Cryptosporidium as described in subsection (a)(4). The system must notify the
Agency no later than three months prior to the date before which the system is
otherwise required to start E. coli monitoring under subsection (c).
4) Smaller System Suppliers
Monitoring for Cryptosporidium. A filtered system supplier serving fewer than
10,000 people must sample its source water for Cryptosporidium at least twice
per month for 12 months or at least monthly for 24 months if it meets any of
the conditions set forth in subsections (a)(4)(A) through (a)(4)(C), subject to
the limitations of subsection (a)(4)(D), based on monitoring conducted under
subsection (a)(3).
A) For a supplier using a
lake or reservoir source, the annual mean E. coli concentration is greater than
10 E. coli/100 mL.
B) For a
supplier using a flowing stream source, the annual mean E. coli concentration
is greater than 50 E. coli/100 mL.
C) The supplier does not conduct E. coli
monitoring as described in subsection (a)(3).
D) A supplier using groundwater under the
direct influence of surface water must comply with the requirements of
subsection (a)(4) based on the E. coli level that applies to the nearest
surface water body. If no surface water body is nearby, the system must comply
based on the requirements that apply to a supplier using a lake or reservoir
source.
5) For a
filtered system supplier serving fewer than 10,000 people, the Agency may issue
a SEP approving monitoring for an indicator other than E. coli under subsection
(a)(3). The Agency may also issue a SEP approving an alternative to the E. coli
concentration in subsection (a)(4)(A), (a)(4)(B), or (a)(4)(D) to trigger
Cryptosporidium monitoring. This approval by the Agency must be provided to the
supplier in writing, and it must include the basis for the Agency's
determination that the alternative indicator or trigger level will provide a
more accurate identification of whether a system will exceed the Bin 1
Cryptosporidium level set forth in Section
611.1010.
6) An unfiltered system supplier serving
fewer than 10,000 people must sample its source water for Cryptosporidium at
least twice per month for 12 months or at least monthly for 24
months.
7) A supplier may sample
more frequently than required by this Section if the sampling frequency is
evenly spaced throughout the monitoring period.
b) Second Round of Source Water Monitoring. A
supplier must conduct a second round of source water monitoring that meets the
requirements for monitoring parameters, frequency, and duration described in
subsection (a), unless it meets the monitoring exemption criteria in subsection
(d). The supplier must conduct this monitoring on the schedule set forth in
subsection (c).
c) Monitoring
Schedule. A supplier must perform the two rounds of monitoring subsections (a)
and (b) require on the schedule in this subsection (c), unless the supplier
meets the monitoring exemption criteria in subsection (d).
1) Suppliers That Serve at Least 100,000
People
A) The suppliers must have begun the
first round of source water monitoring no later than the end of October
2006.
B) The suppliers must have
begun the second round of source water monitoring no later than the end of
April 2015.
2) Suppliers
That Serve from 50,000 to 99,999 People
A) The
suppliers must have begun the first round of source water monitoring no later
than the end of April 2007.
B) The
suppliers must have begun the second round of source water monitoring no later
than the end of October 2015.
3) Suppliers That Serve from 10,000 to 49,999
People
A) The suppliers must have begun the
first round of source water monitoring no later than the end of April
2008.
B) The suppliers must have
begun the second round of source water monitoring no later than the end of
October 2016.
4)
Suppliers That Serve Fewer Than 10,000 People and That Monitor for E. coli
A) The suppliers must have begun the first
round of source water monitoring no later than the end of October
2008.
B) The suppliers must have
begun the second round of source water monitoring no later than the end of
October 2017.
5)
Suppliers That Serve Fewer Than 10,000 People and That Monitor for
Cryptosporidium
A) The suppliers must have
begun the first round of source water monitoring no later than the end of April
2010.
B) The suppliers must have
begun the second round of source water monitoring no later than the end of
April 2019.
BOARD NOTE: The Board retained the past implementation dates
until implementation of the Long Term 2 Enhanced Surface Water Treatment Rule
in this Subpart Z is complete.
d) Monitoring Avoidance
1) A filtered system supplier is not required
to conduct source water monitoring under this Subpart Z if the system will
provide a total of at least
5.5 -log of treatment for
Cryptosporidium, equivalent to meeting the treatment requirements of Bin 4 in
Section 611.1011.
2) An unfiltered system supplier is not
required to conduct source water monitoring under this Subpart Z if the system
will provide a total of at least 3-log Cryptosporidium inactivation, equivalent
to meeting the treatment requirements for an unfiltered system supplier with a
mean Cryptosporidium concentration of greater than
0.01 oocysts/L in Section
611.1012.
3) If a supplier chooses to provide the level
of treatment set forth in subsection (d)(1) or (d)(2), as applicable, rather
than start source water monitoring, it must notify the Agency in writing no
later than the date on which the system is otherwise required to submit a
sampling schedule for monitoring under Section
611.1002. Alternatively, a
supplier may choose to stop sampling at any point after it has initiated
monitoring if it notifies the Agency in writing that it will provide this level
of treatment. The supplier must install and operate technologies to provide
this level of treatment before the applicable treatment compliance date set
forth in Section 611.1013.
e) Plants Operating Only Part of the Year. A
supplier that has a Subpart B plant that operates for only part of the year
must conduct source water monitoring in accordance with this Subpart Z, but
with the following modifications:
1) The
supplier must sample its source water only during the months that the plant
operates, unless the Agency issue a SEP specifying another monitoring period
based on plant operating practices.
2) A supplier with plants that operate less
than six months per year and that monitors for Cryptosporidium must collect at
least six Cryptosporidium samples per year during each of two years of
monitoring. Samples must be evenly spaced throughout the period during which
the plant operates.
f)
New Sources and New Systems
1) New sources. A
supplier that begins using a new source of surface water or groundwater under
the direct influence of surface water after the supplier was required to begin
monitoring under subsection (c) must monitor the new source on a schedule that
the Agency has approved in a SEP. Source water monitoring must meet the
requirements of this Subpart Z. The supplier must also meet the bin
classification and Cryptosporidium treatment requirements of Sections
611.1010 and
611.1011 or Section 611.1012, as
applicable, for the new source on a schedule that the Agency has approved in a
SEP.
2) The requirements of Section
611.1001(f)
apply to a Subpart B system supplier that begins operation after the applicable
monitoring start date set forth in subsection (c).
3) The supplier must begin a second round of
source water monitoring no later than six years following initial bin
classification under Section
611.1010 or determination of the
mean Cryptosporidium level under Section 611.1012.
g) Failure to collect any source water sample
required under this Section in accordance with the sampling schedule, sampling
location, analytical method, approved laboratory, and reporting requirements of
Sections 611.1002 through
611.1006 is a monitoring
violation.
h) Grandfathering
Monitoring Data. A supplier may use (grandfather) monitoring data collected
prior to the applicable monitoring start date in subsection (c) to meet the
initial source water monitoring requirements in subsection (a). Grandfathered
data may substitute for an equivalent number of months at the end of the
monitoring period. All data submitted under this subsection must meet the
requirements set forth in Section
611.1007.
BOARD NOTE: This Section derives from
40 CFR
141.701.
