Current through September 18, 2024
Authority: IC 13-13-5; IC 13-14-8-7; IC 13-14-9; IC 13-18-3;
IC 13-18-16
Affected: IC 13-18
Sec. 38.
(a) All:
(1) large water systems; and
(2) small and medium size water systems that
exceed the lead or copper action level;
shall monitor water quality parameters in addition to lead
and copper in accordance with this section. The requirements of this section
are summarized in the table in subsection (b)(2)(A).
(b) General monitoring
requirements for water quality parameters shall be as follows:
(1) Requirements for sample collection
methods shall be as follows:
(A) Tap samples
shall be representative of water quality throughout the distribution system
taking into account:
(i) the number of persons
served;
(ii) the different sources
of water;
(iii) the different
treatment methods employed by the system; and
(iv) seasonal variability. Tap sampling under
this section is not required to be conducted at taps targeted for lead and
copper sampling under section 37(a) of this rule. (Note: Systems may find it
convenient to conduct tap sampling for water quality parameters at sites used
for coliform sampling under section 8 of this rule.)
(B) Except as provided in subsection (d)(3),
a system shall collect two (2) samples for each applicable water quality
parameter at each entry point to the distribution system during each monitoring
period specified in subsection (c). Samples collected at the entry point to the
distribution system shall be from locations representative of each source after
treatment. If a system draws water from more than one (1) source and the
sources are combined before distribution, the system must sample at an entry
point to the distribution system during periods of normal operating conditions,
that is, when water used is representative of all sources being used.
(2) Requirements for the number of
samples shall be as follows:
(A) Systems
shall collect two (2) tap samples for applicable water quality parameters
during each monitoring period specified under subsections (c) through (f) from
the number of sites listed in the following table:
| System Size (Number of People Served) |
Number of Sites for Water Quality Parameters |
| > 100,000 |
25 |
| 10,001 to 100,000 |
10 |
| 3,301 to 10,000 |
3 |
| 501 to 3,300 |
2 |
| 101 to 500 |
1 |
| < 101 |
1 |
(B)
Systems shall collect two (2) samples for each applicable water quality
parameter at each entry point to the distribution system during each monitoring
period specified in subsection (c). During each monitoring period specified in
subsections (d) through (f), systems shall collect one (1) sample for each
applicable water quality parameter at each entry point to the distribution
system.
(c)
This subsection governs initial sampling. All large water systems shall measure
the applicable water quality parameters as specified in subdivision (1) at taps
and at each entry point to the distribution system during each six (6) month
monitoring period specified in section 37(d)(1) of this rule. All small and
medium size systems shall measure the applicable water quality parameters at
the locations specified in subdivision (1) during each six (6) month monitoring
period specified in section 37(d)(1) of this rule during which the system
exceeds the lead or copper action level. Monitoring requirements for water
quality parameters at taps are as follows:
(1) The following are water quality
parameters:
(A) pH.
(B) Alkalinity.
(C) Orthophosphate, when an inhibitor
containing a phosphate compound is used.
(D) Silica, when an inhibitor containing a
silica compound is used.
(E)
Calcium.
(F)
Conductivity.
(G) Water
temperature.
(2) At each
entry point to the distribution system, all of the applicable parameters listed
in subdivision (1).
(d)
This subsection governs monitoring after installation of corrosion control. Any
large system that installs corrosion control treatment under section 40(d)(4)
of this rule shall measure the water quality parameters at the locations and
frequencies specified in this subsection during each six (6) month monitoring
period specified in section 37(d)(2)(A) of this rule. Any small or medium size
system that installs corrosion control treatment shall conduct monitoring
during each six (6) month monitoring period specified in section 37(d)(2)(B) of
this rule in which the system exceeds the lead or copper action level.
Monitoring requirements for water quality parameters at taps are as follows:
(1) The water quality parameters at taps
require two (2) samples for the following:
(A) pH.
(B) Alkalinity.
(C) Orthophosphate, when an inhibitor
containing a phosphate compound is used.
(D) Silica, when an inhibitor containing a
silicate compound is used.
(E)
Calcium, when calcium carbonate stabilization is used as part of corrosion
control.
(2) Except as
provided in subdivision (3), at each entry point to the distribution system are
one (1) sample not less frequently than every two (2) weeks (biweekly) for the
following:
(A) pH.
(B) When alkalinity is adjusted as part of
optimal corrosion control, a reading of the dosage rate of the chemical used to
adjust alkalinity and the alkalinity concentration.
(C) When a corrosion inhibitor is used as
part of optimal corrosion control, a reading of the dosage rate of the
inhibitor used and the concentration of the orthophosphate or silica, whichever
is applicable.
(3) A
ground water system may limit entry point sampling described in subdivision (2)
to those entry points that are representative of water quality and treatment
conditions throughout the system. If water from untreated ground water sources
mixes with water from treated ground water sources, the system must monitor for
water quality parameters both at representative entry points receiving
treatment and representative entry points receiving no treatment. Prior to the
start of any monitoring under this subdivision, the system shall provide to the
commissioner written information identifying the selected entry points and
documentation, including information on seasonal variability, sufficient to
demonstrate that the sites are representative of water quality and treatment
conditions throughout the system.
(e) This subsection governs monitoring after
water quality parameter values for optimal corrosion control are specified.
After the commissioner specifies the values for applicable water quality
control parameters reflecting optimal corrosion control treatment under section
41(f) of this rule, the following systems shall comply as follows:
(1) Large water systems shall:
(A) measure the applicable water quality
parameters in accordance with subsection (d); and
(B) determine compliance with the
requirements of section 42(g) of this rule every six (6) months with the first
six (6) month period to begin on either January 1 or July 1, whichever comes
first after the commissioner specifies the optimal values under section 41(f)
of this rule.
(2) Any
small or medium size system:
(A) shall conduct
monitoring for the applicable water quality parameters during each six (6)
month period in which the system exceeds the lead or copper action level;
and
(B) that is subject to a
reduced monitoring frequency under section 37(d)(4) of this rule at the time of
the action level exceedance, shall start the applicable six (6) month
monitoring period to coincide with the start of the applicable monitoring
period under section 37(d)(4) of this rule.
Compliance with commissioner-designated optimal water quality
parameter values shall be determined as specified under section 41(g) of this
rule.
(f) The following are requirements for
reduced monitoring:
(1) Any water system that
maintains the range of values for the water quality parameters reflecting
optimal corrosion control treatment during each of two (2) consecutive six (6)
month monitoring periods under subsection (e) shall continue monitoring at the
entry point to the distribution system as specified in subsection (d)(2). The
system may collect two (2) tap samples for applicable water quality parameters
from the reduced number of sites shown in the following table during each six
(6) month monitoring period:
| System Size (Number of People Served) |
Reduced Number of Sites of Water Quality Parameters
|
| > 100,000 |
10 |
| 10,001 to 100,000 |
7 |
| 3,301 to 10,000 |
3 |
| 501 to 3,300 |
2 |
| 101 to 500 |
1 |
| < 101 |
1 |
(2)
This subdivision designates reduced monitoring requirements for water quality
parameters as follows:
(A) Any water system
that maintains the range of values for water quality parameters reflecting
optimal corrosion control treatment specified by the commissioner under section
41(f) of this rule during three (3) consecutive years of monitoring may reduce
the frequency with which it collects the number of tap samples specified in
subdivision (1) for applicable water quality parameters from once every six (6)
months to annually. This sampling begins during the calendar year immediately
following the end of the monitoring period in which the third consecutive year
of six (6) month monitoring occurs. Any water system that maintains the range
of water quality parameters reflecting optimal corrosion control treatment
specified by the commissioner under section 41(f) of this rule during three (3)
consecutive years of annual monitoring under this subdivision may reduce the
frequency with which it collects the number of tap samples for applicable water
quality parameters specified in subdivision (1) from annually to once every
three (3) years. This sampling begins not later than the third calendar year
following the end of the monitoring period in which the third consecutive year
of monitoring occurs.
(B) A water
system may reduce the frequency of collecting tap samples to every three (3)
years for applicable water quality parameters specified in subsection (d)(1) if
the system demonstrates the following during two (2) consecutive monitoring
periods:
(i) The system's tap water lead level
at the ninetieth percentile is less than or equal to the PQL for lead as
specified in section 45(b)(2) of this rule.
(ii) The system's tap water copper level at
the ninetieth percentile is less than or equal to sixty-five hundredths (0.65)
milligram per liter (mg/L) for copper as specified in section 36(c)(2) of this
rule.
(iii) The system has
maintained the range of values for the water quality parameters reflecting
optimal corrosion control treatment specified by the commissioner under section
41(f) of this rule.
Monitoring done every three (3) years must be done not later
than every third calendar year.
(3) A water system that conducts sampling
annually shall collect these samples evenly throughout the year so as to
reflect seasonal variability.
(4)
Any water system subject to the reduced monitoring frequency that fails to
operate at or above the minimum value or within the range of values for the
water quality parameters specified by the commissioner under section 41(f) of
this rule for more than nine (9) days in any six (6) month monitoring period
shall resume distribution tap water sampling in accordance with the number and
frequency requirements in subsection (e). The system may resume:
(A) annual monitoring for water quality
parameters number of sites specified in subdivision (2) after it has completed
two (2) subsequent consecutive six (6) month rounds of monitoring that meet the
criteria of that subsection; or
(B)
triennial monitoring for water quality parameters at the tap at the reduced
number of sites after it demonstrates that it meets the criteria of either
subdivision (2)(A) or (2)(B).
(g) The results of any monitoring conducted
in addition to the minimum requirements of this section shall be considered by
the system and the commissioner in making any determinations, for example,
determining concentrations of water quality parameters under this section or
section 41 of this rule.
