Current through Register Vol. 48, No. 38, September 20, 2024
a) Triggered Source
Water Monitoring
1) General Requirements. A
GWS supplier must conduct triggered source water monitoring if the following
conditions exist.
A) The supplier does not
provide at least 4-log treatment of viruses (using inactivation, removal, or an
Agency-approved combination of 4-log virus inactivation and removal) before or
at the first customer for each groundwater source.
B) This subsection (a)(1)(B) corresponds with
40 CFR
141.802(a)(1)(ii), which has
no operative effect after a past implementation date. This statement maintains
structural consistency with the federal regulations.
C) The system is notified that a sample
collected under Sections
611.1054 through
611.1057 is total
coliform-positive and the sample is not invalidated under Section
611.1053(c).
2) Sampling Requirements. A GWS
supplier must collect, within 24 hours after notification of the total
coliform-positive sample, at least one groundwater source sample from each
groundwater source in use at the time the total coliform-positive sample was
collected under Sections
611.1054 through 611.1057,
except as provided in subsection (a)(2)(B).
A)
The Agency may issue a SEP extending the 24-hour time limit on a case-by-case
basis if it determines that the supplier cannot collect the groundwater source
water sample within 24 hours due to circumstances beyond the supplier's
control. In the case of an extension, the Agency must specify how much time the
supplier has to collect the sample.
B) If approved by the Agency, a supplier with
more than one groundwater source may meet the requirements of this subsection
(a)(2) by sampling a representative groundwater source or sources. If directed
by the Agency in a SEP, the supplier must submit for Agency approval a
triggered source water monitoring plan that identifies one or more groundwater
sources that are representative of each monitoring site in the system's sample
siting plan under Section
611.1053 and that the system
intends to use for representative sampling under this subsection (a).
C) This subsection (a)(2)(C) corresponds with
40 CFR
141.802(a)(1)(ii), a
now-obsolete implementing provision. This statement maintains structural
consistency with the federal regulations.
D) A GWS supplier serving 1,000 or fewer
people may use a repeat sample collected from a groundwater source to meet both
the requirements of Subpart AA and to satisfy the monitoring requirements of
subsection (a)(2) for that groundwater source only if the Agency issues a SEP
approving the use of E. coli as a fecal indicator for source water monitoring
under this subsection (a) and approves the use of a single sample for meeting
both the triggered source water monitoring requirements in this subsection (a)
and the repeat monitoring requirements in Section
611.1058. If the repeat sample
collected from the groundwater source is E. coli-positive, the system must
comply with subsection (a)(3).
3) Additional Requirements. If the Agency
does not require corrective action under Section
611.803(a)(2)
for a fecal indicator-positive source water sample collected under subsection
(a)(2) that is not invalidated under subsection (d), the supplier must collect
five additional source water samples from the same source within 24 hours after
being notified of the fecal indicator-positive sample.
4) Consecutive and Wholesale Systems
A) In addition to the other requirements of
this subsection (a), a consecutive GWS supplier that has a total
coliform-positive sample collected under Sections
611.1054 through 611.1057, must
notify the wholesale systems within 24 hours after being notified of the total
coliform-positive sample.
B) In
addition to the other requirements of this subsection (a), a wholesale GWS
supplier must comply with the following requirements:
i) A wholesale GWS supplier that receives
notice from a consecutive system it serves that a sample collected under
Sections 611.1054 through
611.1057 is total
coliform-positive must, within 24 hours after being notified, collect a sample
from its groundwater sources under subsection (a)(2) and analyze it for a fecal
indicator under subsection (c).
ii)
If the sample collected under subsection (a)(4)(B)(i) is fecal
indicator-positive, the wholesale GWS supplier must notify all consecutive
systems served by that groundwater source of the fecal indicator source water
positive within 24 hours after being notified of the groundwater source sample
monitoring result and must meet the requirements of subsection
(a)(3).
5)
Exceptions to the Triggered Source Water Monitoring Requirements. A GWS
supplier is not required to comply with the source water monitoring
requirements of subsection (a) if either of the following conditions exists:
A) The Agency issues a SEP determining and
documenting that a distribution system deficiency caused the total
coliform-positive sample collected under Sections
611.1054 through 611.1057;
or
B) The total coliform-positive
sample collected under Sections
611.1054 through
611.1057 is collected at a
location that meets Agency criteria for distribution system conditions that
will cause total coliform-positive samples.
b) Assessment Source Water Monitoring. If the
Agency directs in a SEP, a GWS supplier must conduct assessment source water
monitoring that meets Agency-determined requirements for such monitoring. A GWS
supplier conducting assessment source water monitoring may use a triggered
source water sample collected under subsection (a)(2) to meet the requirements
of subsection (b). Agency-determined assessment source water monitoring
requirements may include the following:
1)
Collection of a total of 12 groundwater source samples that represent each
month the system provides groundwater to the public;
2) Collection of samples from each well,
unless the system obtains written Agency approval to conduct monitoring at one
or more wells within the GWS that are representative of multiple wells used by
that system and that draw water from the same hydrogeologic setting;
3) Collection of a standard sample volume of
at least 100 mL for fecal indicator analysis, regardless of the fecal indicator
or analytical method used;
4)
Analysis of all groundwater source samples using one of the analytical methods
listed in subsection (c)(2) for the presence of E. coli, enterococci, or
coliphage;
5) Collection of
groundwater source samples at a location prior to any treatment of the
groundwater source unless the Agency approves a sampling location after
treatment; and
6) Collection of
groundwater source samples at the well itself, unless the system's
configuration does not allow for sampling at the well itself and the Agency
approves in a SEP an alternate sampling location that is representative of the
water quality of that well.
c) Analytical Methods
1) A GWS supplier subject to the source water
monitoring requirements of subsection (a) must collect a standard sample volume
of at least 100 mL for fecal indicator analysis, regardless of the fecal
indicator or analytical method used.
2) A GWS supplier must analyze all
groundwater source samples collected under subsection (a) using one of the
analytical methods listed in subsections (c)(2)(A) through (c)(2)(C), each
incorporated by reference in Section
611.102, or alternative methods
approved by the Agency under Section
611.480, subject to the
limitations of subsection (c)(2)(D), for the presence of E. coli, enterococci,
or coliphage:
A) E. coli. Enzyme Substrate
Technique
i)
Colilert®. SM 9223 B (97), SM 9223 B (04), or SM
9223 B (16).
ii)
Colisure®. SM 9223 B (97), SM 9223 B (04), or SM
9223 B (16).
iii) Membrane Filter
Method with MI Agar. USEPA 1604 (02).
iv) E*Colite (98).
v) EC-MUG. SM 9221 F (94), SM 9221 F (06), or
SM 9221 F (14).
vi) NA-MUG. SM 9222
G (97) (20th ed. only) or SM 9222 I (15).
vii)
Colilert®-18. SM 9223 B (97), SM 9223 B (04), or
SM 9223 B (16).
viii)
Readycult® (07).
ix) Modified ColitagT (09) or Modified
ColitagT (20).
x)
Chromocult® (00).
xi) Tecta (14) or Tecta (17).
xii) RAPID'E. coli (20).
BOARD NOTE: EC-MUG (SM 9221 F (94)
(20th ed. only)) or NA-MUG (SM 9222 G (97)
(20th ed. only)), both incorporated by reference in
Section 611.102, can be used for E. coli testing step, as described in
40 CFR
141.21(f)(6)(i) or
(f)(6)(ii), incorporated by reference in
Section 611.102, after use of SM 9221 B (93), SM 9221 B (94), SM 9221 B (99),
SM 9221 B (06), SM 9221 D (93), SM 9221 D (94), SM 9221 D (99), SM 9221 D (06),
SM 9222 B (91), SM 9222 B (94), SM 9222 B (97), SM 9222 C (91), SM 9222 C (94),
or SM 9222 C (97).
B) E. coli. Fermentation Technique
i) Hach 10029 (99)
(m-ColiBlue24®).
ii) SM 9222 J (15).
C) Enterococci
i) Multiple-Tube Technique. SM 9230 B (93)
(20th ed. only), SM 9230 B (04), SM 9230 C (93)
(20th ed. only), SM 9230 C (13), or USEPA 1600 (02).
BOARD NOTE: The holding time and temperature for groundwater
samples are specified in subsection (c)(2)(D), rather than as specified in
Section 8 of USEPA 1600 (02).
ii) Fluorogenic Substrate Enterococcus Test
(using Enterolert). Enterolert (96) or SM 9230 D (13).
BOARD NOTE: Medium is available through IDEXX Laboratories,
Inc., at the address set forth in Section
611.102(b).
Preparation and use of the medium must be as set forth in the article that
embodies the method as incorporated by reference in Section
611.102(b).
D) Coliphage
i) Two-Step Enrichment Presence-Absence
Procedure. USEPA 1601 (01) or Charm Fast Phage (12).
ii) Single Agar Layer Procedure. USEPA 1602
(01).
E) Limitation on
Methods Use. The time from sample collection to initiation of analysis may not
exceed 30 hours. The GWS supplier is encouraged but is not required to hold
samples below 10° C during transit.
d) Invalidation of a Fecal Indicator-Positive
Groundwater Source Sample
1) A GWS supplier
may obtain Agency invalidation of a fecal indicator-positive groundwater source
sample collected under subsection (a) only under either of the following
conditions:
A) The supplier provides the
Agency with written notice from the laboratory that improper sample analysis
occurred; or
B) The Agency issues a
SEP determining and documenting that substantial evidence that a fecal
indicator-positive groundwater source sample is not related to source water
quality.
2) If the
Agency invalidates a fecal indicator-positive groundwater source sample, the
GWS supplier must collect another source water sample under subsection (a)
within 24 hours after being notified by the Agency of its invalidation
decision, and the supplier must have it analyzed for the same fecal indicator
using the analytical methods in subsection (c). The Agency may extend the
24-hour time limit on a case-by-case basis if the supplier cannot collect the
source water sample within 24 hours due to circumstances beyond its control. In
the case of an extension, the Agency must specify how much time the system has
to collect the sample.
e) Sampling Location
1) Any groundwater source sample required
under subsection (a) must be collected at a location prior to any treatment of
the groundwater source unless the Agency approves a sampling location after
treatment.
2) If the supplier's
system configuration does not allow for sampling at the well itself, it may
collect a sample at an Agency-approved location to meet the requirements of
subsection (a) if the sample is representative of the water quality of that
well.
f) New Sources. If
the Agency directs in a SEP, a GWS supplier placing a new groundwater source
into service must conduct assessment source water monitoring under subsection
(b). If the SEP directs, the supplier must begin monitoring before the
groundwater source is used to provide water to the public.
g) Public Notification. A GWS supplier with a
groundwater source sample collected under subsection (a) or (b) that is fecal
indicator-positive and that is not invalidated under subsection (d), including
a consecutive system supplier served by the groundwater source, must conduct
public notification under Section
611.902.
h) Monitoring Violations. A failure to meet
the requirements of subsections (a) through (f) is a monitoring violation that
requires the GWS supplier to provide public notification under Section
611.904.
BOARD NOTE: This Section derives from
40 CFR
141.402 and appendix A to subpart C of
40 CFR
141. The Board did not separately list
approved alternative methods from Standard Methods Online that are the same
version as a method appearing in a printed edition of Standard Methods. Using
the Standard Methods Online copy is acceptable.
Standard Methods Online, Method 9221 F-06 appears in the
22nd edition as Method 9221 F. This appears in this
Section as SM 9221 F (06).
Standard Methods Online, Method 9222 G-97 appears in the
20th and 21st editions as
Method 9222 G. This appears in this Section as SM 9222 G (97).
Standard Methods Online, Method 9223 B-97 appears in the
20th and 21st editions as
Method 9223 B. This appears in this Section as SM 9223 B (97).
Standard Methods Online, Method 9223 B-04 appears in the
22nd edition as Method 9223 B. This appears in this
Section as SM 9223 B (04).
BOARD NOTE: Derived from
40
CFR 141.402 and appendix A to subpart C of 40
CFR 141 (2017).
