(A) Water systems shall obtain plan approval
by the
director for each microbial toolbox option prior to receiving treatment
credit for the toolbox option. Systems receive the treatment credits listed in
the following table by meeting the conditions for microbial toolbox options
described in paragraphs (B) to (N) of this rule. Systems shall apply these
treatment credits to meet the treatment required by paragraph (E) of rule
3745-81-67 of the Administrative
Code. The following table summarizes options in the microbial toolbox:
MICROBIAL TOOLBOX SUMMARY TABLE: OPTIONS, TREATMENT CREDITS AND
CRITERIA
|
Toolbox Option
|
Cryptosporidium treatment credit with design and
implementation criteria
|
|
Source Protection and Management Toolbox
Options
|
|
(1) Watershed control program...
|
0.5 -log credit for director-approved program
comprising required elements, annual program status report to director, and
regular watershed survey. Specific criteria are in paragraph (B) of this
rule.
|
|
(2) Alternative source/intake
management...
|
No prescribed credit. Systems may conduct simultaneous
monitoring for treatment bin classification at alternative intake locations or
under alternative intake management strategies. Specific criteria are in
paragraph (C) of this rule.
|
|
Pre Filtration Toolbox Options
|
|
(3) Presedimentation basin with
coagulation...
|
0.5 -log credit during any month that presedimentation
basins achieve a monthly mean reduction of 0.5 -log or greater in turbidity or
alternative director-approved performance criteria. To be eligible, basins
shall be operated continuously with coagulant addition and all plant flow shall
pass through basins. Specific criteria are in paragraph (D) of this
rule.
|
|
(4) Two-stage lime softening...
|
0.5 -log credit for two-stage softening where chemical
additional and hardness precipitation occur in both stages. All plant flow
shall pass through both stages. Singlestage softening is credited as equivalent
to conventional treatment. Specific criteria are in paragraph (E) of this
rule.
|
|
(5) Bank filtration...
|
0.5 -log credit for 25-foot setback; 1.0 -log credit
for 50-foot setback; aquifer shall be unconsolidated sand containing at least
10 per cent fines; average turbidity in wells shall be less than 1 NTU. Systems
using wells followed by filtration when conducting source water monitoring
shall sample the well to determine bin classification and are not eligible for
additional credit. Specific criteria are in paragraph (F) of this
rule.
|
|
Treatment Performance Toolbox Options
|
|
(6) Combined filter performance...
|
0.5 -log credit for combined filter effluent turbidity
less than or equal to 0.15 NTU in at least 95 per cent of measurements each
month. Specific criteria are in paragraph (G) of this rule.
|
|
(7) Individual filter performance...
|
0.5 -log credit (in addition to 0.5 -log combined
filter performance credit) if individual filter effluent turbidity is less than
or equal to 0.15 NTU in at least 95 per cent of samples each month in each
filter and is never greater than 0.3 NTU in two consecutive measurements in any
filter. Specific criteria are in paragraph (H) of this rule.
|
|
(8) Demonstration of performance...
|
Credit awarded to unit process or treatment train based
on a demonstration to the director with a director-accepted protocol. Specific
criteria are in paragraph (I) of this rule.
|
|
Additional Filtration Toolbox Options
|
|
(9) Bag or cartridge filters (individual
filters)...
|
Up to 2-log credit based on the removal efficiency
demonstrated during challenge testing with a 1.0 -log factor of safety.
Specific criteria are in paragraph (J) of this rule.
|
|
(10) Bag or cartridge filters (in
series)...
|
Up to 2.5 -log credit based on the removal efficiency
demonstrated during challenge testing with a 0.5 -log factor of safety.
Specific criteria in paragraph (J) of this
rule.
|
|
(11) Membrane filtration...
|
Log credit equivalent to removal efficiency
demonstrated in challenge test for device if supported by direct integrity
testing. Specific criteria are in paragraph (K) of this rule.
|
|
(12) Second stage filtration...
|
0.5 -log credit for second separate granular media
filtration stage if treatment train includes coagulation prior to first filter.
Specific criteria are in paragraph (L) of this rule.
|
|
(13) Slow sand filters....
|
2.5 -log credit as a secondary filtration step; 3.0
-log credit as a primary filtration process. No prior chlorination for either
option. Specific criteria are in paragraph (M) of this rule.
|
|
Inactivation Toolbox Options
|
|
(14) Chlorine dioxide...
|
Log credit based on measured CT in relation to CT
table. Specific criteria in paragraph (N)(2) of this rule.
|
|
(15) Ozone...
|
Log credit based on measured CT in relation to CT
table. Specific criteria in paragraph (N)(2) of this rule.
|
|
(16) UV...
|
Log credit based on validated UV dose in relation to UV
dose table; reactor validation testing required to establish UV dose and
associated operating conditions. Specific criteria in paragraph (N)(4) of this
rule.
|
(B)
Watershed control program.
Systems received 0.5 -log Cryptosporidium treatment credit for
implementing a watershed control program that meets the
requirements of this paragraph
following :
.
(1)
Systems that intend to apply for the watershed control program credit shall
notify the
director of this intent no later than two years prior to the
treatment compliance date applicable to the system in paragraph (F) of rule
3745-81-67 of the Administrative
Code.
(2) Systems shall submit to
the
director a proposed watershed control plan no later than one year before
the applicable treatment compliance date in paragraph (F) of rule
3745-81-67 of the Administrative
Code. The
director shall approve the watershed control plan for the system to
receive watershed control program treatment credit. The watershed control plan
shall include the following elements:
(a)
Identification of an area of influence outside of which the likelihood of
Cryptosporidium or fecal contamination affecting the treatment
plant intake is
not significant as approved by the
director. This is the area to be evaluated
in future watershed surveys in accordance with paragraph (B)(4)(b) of this
rule. The area of influence shall include, at a minimum
, the following:
(i)
For systems using inland streams, reservoirs, and lakes, the drinking water
source protection area with primary focus on the corridor management zone and
any additional areas within the watershed that have been specifically
identified by the public water system or the director as possible sources of
Cryptosporidium.
(ii) For systems
using the Ohio river, the zone of critical concern.
(iii) For systems using lake Erie, the
potential influence zone, where this zone has been delineated.
(b) Identification of both
potential and actual sources of Cryptosporidium contamination and an assessment
of the relative impact of these sources on the system's source water
quality.
(c) An analysis of the
effectiveness and feasibility of control measures that could reduce
Cryptosporidium loading from sources of contamination to the system's source
water.
(d) A statement of goals and
specific actions the system will undertake to reduce source water
Cryptosporidium levels. The plan shall explain how the actions are expected to
contribute to specific goals, identify watershed partners and their roles,
identify resource requirements and commitments, and include a schedule for plan
implementation with deadlines for completing specific actions identified in the
plan.
(3) Systems with
existing watershed control programs (i.e., programs in place on January 5,
2006) are eligible to seek this credit.
Their
the watershed
control plans shall meet the criteria in paragraph (B)(2) of this rule and
shall specify ongoing and future actions that will reduce
source water
Cryptosporidium levels.
(4) Systems
shall complete the following actions to maintain the 0.5 -log credit.
(a) Submit an annual watershed control
program status report to the
director. The annual watershed control program
status report shall
do the following:
describe the system's implementation of the approved
plan and assess the adequacy of the plan to meet its goals. It shall explain
how the system is addressing any shortcomings in plan implementation, including
those previously identified by the director or as the result of the watershed
survey conducted under paragraph (B)(4)(b) of this rule. It shall also describe
any significant changes that have occurred in the watershed since the last
watershed sanitary survey. If
(i)
Describe the system's implementation of the approved
plan and assess the adequacy of the plan to meet the goals.
(ii)
Explain how the
system is addressing any shortcomings in plan implementation, including those
previously identified by the director or as the result of the watershed survey
conducted under paragraph (B)(4)(b) of this rule.
(iii)
Describe any
significant changes that have occurred in the watershed since the last
watershed sanitary survey.
(b)
If a system
determines during implementation that making a significant change to
its
the
system's approved watershed control program is necessary, the system
shall notify the
director prior to making any such changes. If any change is
likely to reduce the level of
source water protection, the system shall also
list in
its
the notification the actions the system will take to
mitigate this effect.
(b)(c) Undergo a watershed
sanitary survey every three years for community water systems and every five
years for non-community water systems and submit the survey report to the
director. The survey shall be conducted according to Ohio environmental
protection agency guidelines and by persons acceptable to the
director.
(i) The watershed
sanitary survey shall meet
the following criteria:
encompass the region
identified in the director-approved watershed control plan as the area of
influence; assess the implementation of actions to reduce source water
Cryptosporidium levels; and identify any significant new sources of
Cryptosporidium.
(a)
Encompass the region identified in the
director-approved watershed control plan as the area of
influence.
(b)
Assess the implementation of actions to reduce source
water Cryptosporidium levels.
(c)
Identify any
significant new sources of Cryptosporidium.
(ii) If the director determines that
significant changes may have occurred in the watershed since the previous
watershed sanitary survey, systems shall undergo another watershed sanitary
survey by a date the director requires, which may be earlier than the regular
date in paragraph (B)(4)(b) of this rule.
(c)(d) The system shall
make the watershed control plan, annual status reports, and watershed sanitary
survey reports available to the public upon request. These documents shall be
in a plain language style and include criteria by which to evaluate the success
of the program in achieving plan goals. The director may accept systems to
withhold from the public portions of the annual status report, watershed
control plan, and watershed sanitary survey based on water supply security
considerations.
(5) If
the
director determines that a system is not carrying out the approved
watershed control plan, or if conditions change from those approved, the
watershed control plan may no longer be approvable. An approvable plan
must
shall be
submitted to maintain the watershed control program treatment credit.
(C) Alternative
source.
(1) A system may conduct
source water
monitoring that reflects a different intake location (either in the same
source
or for an alternate
source) or a different procedure for the timing or level of
withdrawal from the
source (alternative
source monitoring). If the
director
approves, a system may determine
its
the bin classification in accordance with paragraphs
(A) to (D) of rule
3745-81-67 of the Administrative
Code based on the alternative
source monitoring results.
(2) If systems conduct alternative
source
monitoring in accordance with paragraph (C)(1) of this rule, systems shall also
monitor their current
plant intake concurrently as described in paragraphs (A)
to (H) of rule
3745-81-65 of the Administrative
Code.
(3) Alternative
source
monitoring under paragraph (C)(1) of this rule shall meet the requirements for
source monitoring to determine bin classification, as described in rule
3745-81-65, paragraphs (H) to (J) of rule 3745-81-27, rule 3745-89-11, and
paragraph (A) of rule
3745-81-66 of the Administrative
Code. Systems shall report the alternative
source monitoring results to the
director, along with supporting information documenting the operating
conditions under which the samples were collected.
(4) If a system determines
its
the bin
classification in accordance with paragraphs (A) to (D) of rule
3745-81-67 of the Administrative
Code using alternative
source monitoring results that reflect a different
intake location or a different procedure for managing the timing or level of
withdrawal from the
source, the system shall relocate the intake or permanently
adopt the withdrawal procedure, as applicable, no later than the applicable
treatment compliance date in paragraph (F) of rule
3745-81-67 of the Administrative
Code.
(D)
Presedimentation.
Systems receive 0.5 -log Cryptosporidium treatment credit for a
presedimentation basin during any month the process meets the
following criteria in
this paragraph.
:
(1) The presedimentation basin shall be in
continuous operation and shall treat the entire plant flow taken from a surface
water source.
(2) The system shall
continuously add a coagulant to the presedimentation basin.
(3) The
presedimentation basin shall achieve
the
following performance criteria
:
in paragraph (D)(3)(a) or
(D)(3)(b) of this rule.
(a)
Demonstrates at least 0.5 -log mean reduction of influent turbidity. This
reduction shall be determined using daily turbidity measurements in the
presedimentation process influent and effluent and shall be calculated as
follows:
log10 (monthly mean of daily influent
turbidity) - log10 (monthly mean of daily effluent
turbidity).
The daily turbidity measurements shall be taken under normal
operating conditions for that day. Presedimentation operations shall not be
altered for the sole purpose of influencing sample results.
(b) Complies with director-approved
performance criteria that demonstrate at least 0.5 -log mean removal of micron
sized particulate material through the presedimentation process.
(E) Two-stage lime
softening.
Systems receive an additional 0.5 -log Cryptosporidium
treatment credit for a twostage lime softening plant if chemical addition and
hardness precipitation occur in two separate and sequential softening stages
prior to filtration. Both softening stages shall treat the entire plant flow
taken from a surface water source.
(F) Bank filtration.
Systems receive Cryptosporidium treatment credit for bank
filtration that serves as pretreatment to a filtration plant by meeting the
criteria in this paragraph. Systems using bank filtration
when they begin
beginning source water monitoring in accordance with
paragraph (A) of rule
3745-81-65 of the Administrative
Code shall collect samples as described in paragraph (J)(4) of rule
3745-81-65 of the Administrative
Code and are not eligible for this credit.
(1) Wells with a ground water flow path of at
least twenty-five feet receive 0.5 -log treatment credit; wells with a ground
water flow path of at least fifty feet receive 1.0 -log treatment credit. The
ground water flow path shall be determined as specified in paragraph (F)(4) of
this rule.
(2) Only wells in
granular aquifers are eligible for treatment credit. Granular aquifers are
those comprised of sand, clay, silt, rock fragments, pebbles or larger
particles, and minor cement. A system shall characterize the aquifer at the
well site to determine aquifer properties. Systems shall extract a core from
the aquifer and demonstrate that in at least ninety per cent of the core
length, grains less than 1.0 millimeters in diameter constitute at least ten
per cent of the core material.
(3)
Only horizontal and vertical wells are eligible for treatment credit.
(4) For vertical wells, the ground water flow
path is the measured distance from the edge of the surface water body under
high flow conditions (determined by the one hundred year floodplain elevation
boundary or by the floodway, as defined in Federal emergency management agency
flood hazard maps) to the well screen. For horizontal wells, the ground water
flow path is the measured distance from the bed of the river under normal flow
conditions to the closest horizontal well lateral screen.
(5) Systems shall monitor each wellhead for
turbidity at least once within the first and last hours of bank filtration
operation and at least every four hours in between. If monthly average
turbidity levels, based on daily maximum values in the well, exceed one NTU,
the system shall report this result to the director and conduct an assessment
within thirty days to determine the cause of the high turbidity levels in the
well. If the director determines that microbial removal has been compromised,
the bank filtration credit may no longer be approvable. To maintain the bank
filtration treatment credit, the system shall implement corrective actions to
remediate the problem and submit approvable plans.
(6) Springs and infiltration galleries are
not eligible for treatment credit under paragraph (F) of this rule, but are
eligible for credit under paragraph (I) of this rule.
(7) Bank filtration demonstration of
performance. The
director may approve Cryptosporidium treatment credit for
bank
filtration based on a demonstration of performance study that meets the
criteria in this paragraph. This treatment credit may be greater than 1.0 -log
and may be awarded to
bank filtration that does not meet the criteria in
paragraphs (F)(1) to (F)(5) of this rule.
(a)
The study shall follow a protocol acceptable to the director and shall involve
the collection of data on the removal of Cryptosporidium or a surrogate for
Cryptosporidium and related hydrogeologic and water quality parameters during
the full range of operating conditions.
(b) The study shall include sampling both
from the production
well(s)
wells and from
monitoring wells that are screened and located along the shortest flow path
between the
surface water source and the production
well(s)
wells.
(G) Combined filter performance.
Systems using conventional filtration treatment or direct
filtration treatment receive an additional 0.5 -log Cryptosporidium treatment
credit during any month the system meets the criteria in this paragraph.
Combined filter effluent (CFE) turbidity shall be less than or equal to 0.15
NTU in at least ninety-five per cent of the measurements. Turbidity shall be
measured as described in paragraph (C)(3) of rule
3745-81-27 and paragraph (A) of
rule 3745-81-74 of the Administrative
Code.
(H) Individual filter
performance.
Systems using conventional filtration treatment or direct
filtration treatment receive 0.5 -log Cryptosporidium treatment credit, which
can be in addition to the 0.5 -log credit under paragraph (G) of this rule,
during any month the system meets the criteria in this paragraph. Compliance
with these criteria shall be based on individual filter turbidity monitoring as
described in paragraphs (B) and (C) of rule
3745-81-74 of the Administrative
Code, as applicable.
(1) The filtered
water turbidity for each individual filter shall be less than or equal to 0.15
NTU in at least ninety-five per cent of the measurements recorded each
month.
(2) No individual filter may
have a measured turbidity greater than 0.3 NTU in two consecutive measurements
taken fifteen minutes apart.
(3)
Any system that has received treatment credit for individual filter performance
and fails to meet the requirements of paragraph (H)(1) or (H)(2) of this rule
during any month does not receive a
treatment technique violation under
paragraph (E)(4) of rule
3745-81-67 of the Administrative
Code if the
director determines the following:
(a) The failure was due to unusual and
short-term circumstances that could not reasonably be prevented through
optimizing treatment plant design, operation, and maintenance.
(b) The system has experienced no more than
two such failures in any calendar year.
(I) Demonstration of performance.
The director may approve Cryptosporidium treatment credit for
drinking water treatment processes based on a demonstration of performance
study that meets the criteria in this paragraph. This treatment credit may be
greater than or less than the prescribed treatment credits in paragraph (E) of
rule 3745-81-67 of the Administrative
Code or paragraphs (D) to (N) of this rule and may be awarded to treatment
processes that do not meet the criteria for the prescribed credits.
(1) Systems cannot receive the prescribed
treatment credit for any toolbox option in paragraphs (D) to (N) of this rule
if that toolbox option is included in a demonstration of performance study for
which treatment credit is awarded under this paragraph.
(2) The demonstration of performance study
shall follow a protocol acceptable to the director and shall demonstrate the
level of Cryptosporidium reduction the treatment process will achieve under the
full range of expected operating conditions for the system.
(3) Approval by the director shall be in
writing and may include monitoring and treatment performance criteria that the
system shall demonstrate and report on an ongoing basis to remain eligible for
the treatment credit. The director may designate such criteria where necessary
to verify that the conditions under which the demonstration of performance
credit was approved are maintained during routine operation.
(J) Bag and
cartridge filters.
Systems receive Cryptosporidium treatment credit of up to 2.0
-log for individual bag or cartridge filters and up to 2.5 -log for bag or
cartridge filters operated in series by meeting the criteria in paragraphs
(J)(1) to (J)(10) of this rule. To be eligible for this credit, systems shall
report the results of challenge testing that meets the requirements of
paragraphs (J)(2) to (J)(9) of this rule to the director. The filters shall
treat the entire plant flow taken from a surface water source.
(1) The Cryptosporidium treatment credit
awarded to bag or cartridge filters shall be based on the removal efficiency
demonstrated during challenge testing that is conducted according to the
criteria in paragraphs (J)(2) to (J)(9) of this rule. A factor of safety equal
to 1-log for individual bag or cartridge filters and 0.5 -log for bag or
cartridge filters in series shall be applied to challenge testing results to
determine removal credit. Systems may use results from challenge testing
conducted prior to January 5, 2006 if the prior testing was consistent with the
criteria specified in paragraphs (J)(2) to (J)(9) of this rule.
(2) Challenge testing shall be performed on
full-scale bag or cartridge filters, and the associated filter housing or
pressure vessel, that are identical in material and construction to the filters
and housings the system will use for removal of Cryptosporidium. Bag or
cartridge filters shall be challenge tested in the same configuration that the
system will use, either as individual filters or as a series configuration of
filters.
(3) Challenge testing
shall be conducted using Cryptosporidium or a surrogate that is removed no more
efficiently than Cryptosporidium. The microorganism or surrogate used during
challenge testing is referred to as the challenge particulate. The
concentration of the challenge particulate shall be determined using a method
capable of discretely quantifying the specific microorganism or surrogate used
in the test; gross measurements such as turbidity may not be used.
(4) The maximum feed water concentration that
can be used during a challenge test shall be based on the detection limit of
the challenge particulate in the filtrate (i.e., filtrate detection limit) and
shall be calculated using the following equation:
Maximum Feed Concentration = 1 x 104
x (filtrate detection limit)
(5) Challenge testing shall be conducted at
the maximum design flow rate for the filter as specified by the
manufacturer.
(6) Each filter
evaluated shall be tested for the duration sufficient to reach one hundred per
cent of the terminal pressure drop, which establishes the maximum pressure drop
under which the filter may be used to comply with the requirements in paragraph
(E) of rule
3745-81-67 of the Administrative
Code.
(7) Removal efficiency of a
filter shall be determined from the results of the challenge test and expressed
in terms of log removal values using the following equation:
LRV = LOG10(Cf) -
LOG10(Cp)
Where: LRV = log removal value demonstrated during challenge
testing; Cf = the feed concentration measured during the challenge test; and Cp
= the filtrate concentration measured during the challenge test. In applying
this equation, the same units shall be used for the feed and filtrate
concentrations. If the challenge particulate is not detected in the filtrate,
then the term Cp shall be set equal to the detection limit.
(8) Each filter tested shall be challenged
with the challenge particulate during three periods over the filtration cycle:
within two hours of start-up of a new filter; when the pressure drop is between
forty-five and fifty-five per cent of the terminal pressure drop; and at the
end of the cycle after the pressure drop has reached one hundred per cent of
the terminal pressure drop. An LRV shall be calculated for each of these
challenge periods for each filter tested. The LRV for the filter (LRVfilter)
shall be assigned the value of the minimum LRV observed during the three
challenge periods for that filter.
(9) If fewer than twenty filters are tested,
the overall removal efficiency for the filter product line shall be set equal
to the lowest LRVfilter among the filters tested. If twenty or more filters are
tested, the overall removal efficiency for the filter product line shall be set
equal to the tenth percentile of the set of LRVfilter values for the various
filters tested. The percentile is defined by (i/(n +1)) where "i" is the rank
of "n" individual data points ordered lowest to highest. If necessary, the
tenth percentile may be calculated using linear interpolation.
(10) If a previously tested filter is
modified in a manner that could change the removal efficiency of the filter
product line, challenge testing to demonstrate the removal efficiency of the
modified filter shall be conducted and submitted to the director.
(K) Membrane filtration.
(1) Systems receive Cryptosporidium treatment
credit for
membrane filtration that meets the criteria of this paragraph.
Membrane
cartridge filters that meet the definition of
membrane filtration in
rule
3745-81-01 of the Administrative
Code are eligible for this credit. The level of treatment credit a system
receives is equal to the lower of the values determined under paragraphs
(K)(1)(a) and (K) (1)(b) of this rule. The U.S. EPA "Membrane Guidance Manual
for the Final Long Term 2 Enhanced
Surface Water Treatment Rule" (November
2005), shall be used as a guide in the technical review of plans submitted for
approval of membrane facilities. Approval of plans for membrane facilities may
be conditioned upon requirements that may be necessary or desirable to ensure
that the system being constructed, or of which the proposed project is a part,
will be able to meet generally accepted standards for the design, equipping and
operation of membrane facilities. Systems shall keep daily operational logs
used to determine monthly compliance with the direct and indirect integrity
testing requirements. The operational logs
must
shall be signed
by an operator of record and kept on a form acceptable to the
director.
Operational logs
must
shall be made available for review upon request.
(a) The removal efficiency demonstrated
during challenge testing conducted under the conditions in paragraph (K)(2) of
this rule.
(b) The maximum removal
efficiency that can be verified through direct integrity testing used with the
membrane filtration process under the conditions in paragraph (K)(3) of this
rule.
(2) Challenge
testing.
The membrane used by the system shall undergo challenge testing
to evaluate removal efficiency, and the system shall report the results of
challenge testing to the director. Challenge testing shall be conducted
according to the criteria in paragraphs (K)(2)(a) to (K)(2)(g) of this rule.
Systems may use data from challenge testing conducted prior to January 5, 2006
if the prior testing was consistent with the criteria in paragraphs (K)(2)(a)
to (K)(2)(g) of this rule.
(a)
Challenge testing shall be conducted on either a full-scale membrane module,
identical in material and construction to the membrane modules used in the
system's treatment facility, or a smaller-scale membrane module, identical in
material and similar in construction to the full-scale module. A module is
defined as the smallest component of a membrane unit in which a specific
membrane surface area is housed in a device with a filtrate outlet
structure.
(b) Challenge testing
shall be conducted using Cryptosporidium oocysts or a surrogate that is removed
no more efficiently than Cryptosporidium oocysts. The organism or surrogate
used during challenge testing is referred to as the challenge particulate. The
concentration of the challenge particulate, in both the feed and filtrate
water, shall be determined using a method capable of discretely quantifying the
specific challenge particulate used in the test; gross measurements such as
turbidity may not be used.
(c) The
maximum feed water concentration that can be used during a challenge test is
based on the detection limit of the challenge particulate in the filtrate and
shall be determined according to the following equation:
maximum feed concentration =
3.16 x
106 x (filtrate detection limit)
(d) Challenge testing shall be conducted
under representative hydraulic conditions at the maximum design flux and
maximum design process recovery specified by the manufacturer for the membrane
module. Flux is defined as the throughput of a pressure driven membrane process
expressed as flow per unit of membrane area. Recovery is defined as the
volumetric per cent of feed water that is converted to filtrate over the course
of an operating cycle uninterrupted by events such as chemical cleaning or a
solids removal process (e.g., backwashing).
(e) Removal efficiency of a membrane module
shall be calculated from the challenge test results and expressed as a log
removal value according to the following equation:
LRV = LOG10(Cf) -
LOG10(Cp)
Where:
LRV = log removal value demonstrated during the challenge test;
Cf = the feed concentration measured during the challenge test; and Cp = the
filtrate concentration measured during the challenge test.
Equivalent units shall be used for the feed and filtrate
concentrations. If the challenge particulate is not detected in the filtrate,
the term Cp is set equal to the detection limit for the purpose of calculating
the LRV. An LRV shall be calculated for each membrane module evaluated during
the challenge test.
(f) The
removal efficiency of a membrane filtration process demonstrated during
challenge testing shall be expressed as a log removal value
(LRVC-Test). If fewer than twenty modules are tested,
then LRVC-Test is equal to the lowest of the
representative LRVs among the modules tested. If twenty or more modules are
tested, then LRVC-Test is equal to the tenth percentile
of the representative LRVs among the modules tested. The percentile is defined
by (i/(n+1)) where "i" is the rank of "n" individual data points ordered lowest
to highest. If necessary, the tenth percentile may be calculated using linear
interpolation.
(g) The challenge
test shall establish a quality control release value (QCRV) for a
non-destructive performance test that demonstrates the Cryptosporidium removal
capability of the membrane filtration module. This performance test shall be
applied to each production membrane module used by the system that was not
directly challenge tested in order to verify Cryptosporidium removal
capability. Production modules that do not meet the established QCRV are not
eligible for the treatment credit demonstrated during the challenge
test.
(h) If a previously tested
membrane is modified in a manner that could change the removal efficiency of
the membrane or the applicability of the nondestructive performance test and
associated QCRV, additional challenge testing to demonstrate the removal
efficiency of, and determine a new QCRV for, the modified membrane shall be
conducted and submitted to the director.
(3) Direct integrity testing.
Systems shall conduct direct integrity testing in a manner that
demonstrates a removal efficiency equal to or greater than the removal credit
awarded to the membrane filtration process and meets the requirements described
in paragraphs (K)(3)(a) to (K)(3)(f) of this rule. A direct integrity test is
defined as a physical test applied to a membrane unit in order to identify and
isolate integrity breaches (e.g., one or more leaks that could result in
contamination of the filtrate).
(a)
The direct integrity test shall be independently applied to each membrane unit
in service. A membrane unit is defined as a group of membrane modules that
share common valving that allows the unit to be isolated from the rest of the
system for the purpose of integrity testing or other maintenance.
(b) The direct integrity method shall have a
resolution of three micrometers or less, where resolution is defined as the
size of the smallest integrity breach that contributes to a response from the
direct integrity test.
(c) The
direct integrity test shall have the sensitivity sufficient to verify the log
treatment credit approved by the
director for the
membrane filtration process,
where sensitivity is defined as the maximum log removal value that can be
reliably verified by a direct integrity test. Sensitivity shall be determined
using the approach in either paragraph (K)(3)(c)(i) or (K) (3)(c)(ii) of this
rule as applicable to the type of direct integrity test the system uses.
(i) For direct integrity tests that use an
applied pressure or vacuum, the direct integrity test sensitivity shall be
calculated according to the following equation:
LRVDIT = LOG10
(Qp /(VCF x Qbreach))
Where:
LRVDIT = the sensitivity of the direct integrity test;
Qp = total design filtrate flow from the membrane unit;
Qbreach = flow of water from an integrity breach
associated with the smallest integrity test response that can be reliably
measured; and VCF = volumetric concentration factor. The volumetric
concentration factor is the ratio of the suspended solids concentration on the
high pressure side of the membrane relative to that in the feed water.
(ii) For direct integrity tests
that use a particulate or molecular marker, the direct integrity test
sensitivity shall be calculated according to the following equation:
LRVDIT =
LOG10(Cf) -
LOG10(Cp)
Where:
LRVDIT = the sensitivity of the direct
integrity test; Cf= the typical feed concentration of
the marker used in the test; and Cp = the filtrate
concentration of the marker from an integral membrane unit.
(d) Systems shall establish a
control limit within the sensitivity limits of the direct integrity test that
is indicative of an integral membrane unit capable of meeting the removal
credit approved by the director.
(e) If the result of a direct integrity test
exceeds the control limit established under paragraph (K)(3)(d) of this rule,
the system shall remove the membrane unit from service. Systems shall conduct a
direct integrity test to verify any repairs, and may return the membrane unit
to service only if the direct integrity test is within the established control
limit.
(f) Systems shall conduct
direct integrity testing on each membrane unit at a frequency of not less than
once each day that the membrane unit is in operation. The director may approve
less frequent testing, based on demonstrated process reliability, the use of
multiple barriers effective for Cryptosporidium, or reliable process
safeguards.
(4) Indirect
integrity monitoring.
Systems shall conduct continuous indirect integrity monitoring
on each membrane unit according to the criteria in paragraphs (K)(4)(a) to
(K)(4)(f) of this rule. Indirect integrity monitoring is defined as monitoring
some aspect of filtrate water quality that is indicative of the removal of
particulate matter. A system that implements continuous direct integrity
testing of membrane units in accordance with the criteria in paragraphs
(K)(3)(a) to (K)(3)(f) of this rule is not subject to the requirements for
continuous indirect integrity monitoring. Systems shall submit a monthly report
to the director summarizing all continuous indirect integrity monitoring
results triggering direct integrity testing and the corrective action that was
taken in each case.
(a) Unless the
director approves an alternative parameter, continuous indirect integrity
monitoring shall include continuous filtrate turbidity monitoring.
(b) Continuous monitoring shall be conducted
at a frequency of no less than once every fifteen minutes.
(c) Continuous monitoring shall be separately
conducted on each membrane unit.
(d) If indirect integrity monitoring includes
turbidity and if the filtrate turbidity readings are above 0.15 NTU for a
period greater than fifteen minutes (i.e., two consecutive fifteen-minute
readings above 0.15 NTU), direct integrity testing shall immediately be
performed on the associated membrane unit as specified in paragraphs (K)(3)(a)
to (K)(3)(f) of this rule.
(e) The
public water system shall validate the continuous measurement for accuracy on a
regular basis using a protocol acceptable to the director.
(f) If indirect integrity monitoring includes
a director-approved alternative parameter and if the alternative parameter
exceeds a directorapproved control limit for a period greater than fifteen
minutes, direct integrity testing shall immediately be performed on the
associated membrane units as specified in paragraphs (K)(3)(a) to (K)(3)(f) of
this rule.
(L) Second stage
filtration.
Systems receive 0.5 -log Cryptosporidium treatment credit for a
separate second stage of filtration that consists of sand, dual media, GAC, or
other fine grain media following granular media filtration if the director
approves. To be eligible for this credit, the first stage of filtration shall
be preceded by a coagulation step and both filtration stages shall treat the
entire plant flow taken from a surface water source. A cap, such as GAC, on a
single stage of filtration is not eligible for this credit. The director shall
approve the treatment credit based on an assessment of the design
characteristics of the filtration process.
(M) Slow sand filtration (as secondary
filter).
Systems are eligible to receive 2.5 -log Cryptosporidium
treatment credit for a slow sand filtration process that follows a separate
stage of filtration if both filtration stages treat entire plant flow taken
from a surface water source and no disinfectant residual is present in the
influent water to the slow sand filtration process. The director shall approve
the treatment credit based on an assessment of the design characteristics of
the filtration process. This paragraph does not apply to treatment credit
awarded to slow sand filtration used as a primary filtration process.
(N) Inactivation toolbox
components.
(1) Calculation of CT values.
(a) CT is the product of the
disinfectant
contact time ("T", in minutes) and
disinfectant concentration ("C", in
milligrams per liter). Systems with treatment credit for chlorine dioxide or
ozone under paragraph (N)(2) or (N)(3) of this rule shall calculate CT at least
once each day, with both "C" and "T" measured during peak hourly flow as
specified in rules
3745-81-27 and
3745-81-72 of the Administrative
Code.
(b) Systems with several
disinfection segments in sequence may calculate CT for each segment, where a
disinfection segment is defined as a treatment unit process with a measurable
disinfectant residual level and a liquid volume. Under this approach, systems
shall add the Cryptosporidium CT values in each segment to determine the total
CT for the treatment plant.
(2) CT values for chlorine dioxide and ozone.
(a) Systems receive the Cryptosporidium
treatment credit listed in this table by meeting the corresponding chlorine
dioxide CT value for the applicable water temperature, as described in
paragraph (N)(1) of this rule.
CT Values (MG-MIN/L) for Cryptosporidium Inactivation by
Chlorine Dioxide 1
|
Log credit
|
Water Temperature, Cº
|
|
<= 0.5
|
1
|
2
|
3
|
5
|
7
|
10
|
15
|
20
|
25
|
30
|
|
(i) 0.25...
|
159
|
153
|
140
|
128
|
107
|
90
|
69
|
45
|
29
|
19
|
12
|
|
(ii) 0.50...
|
319
|
305
|
279
|
256
|
214
|
180
|
138
|
89
|
58
|
38
|
24
|
|
(iii) 1.0...
|
637
|
610
|
558
|
511
|
429
|
360
|
277
|
179
|
116
|
75
|
49
|
|
(iv) 1.5...
|
956
|
915
|
838
|
767
|
643
|
539
|
415
|
268
|
174
|
113
|
73
|
|
(v) 2.0...
|
1275
|
1220
|
1117
|
1023
|
858
|
719
|
553
|
357
|
232
|
150
|
98
|
|
(vi) 2.5...
|
1594
|
1525
|
1396
|
1278
|
1072
|
899
|
691
|
447
|
289
|
188
|
122
|
|
(vii) 3.0...
|
1912
|
1830
|
1675
|
1534
|
1286
|
1079
|
830
|
536
|
347
|
226
|
147
|
1 Systems may use this equation to
determine log credit between the indicated values: Log credit = (0.001506 x
(1.09116) Temp) x CT.
(b) Systems receive the Cryptosporidium
treatment credit listed in this table by meeting the corresponding ozone CT
values for the applicable water temperature, as described in paragraph (N)(1)
of this rule.
CT Values (MG-MIN/L) for Cryptosporidium Inactivation by Ozone
1
|
Log credit
|
Water Temperature, Cº
|
|
<= 0.5
|
1
|
2
|
3
|
5
|
7
|
10
|
15
|
20
|
25
|
30
|
|
(i) 0.25...
|
6.0
|
5.8
|
5.2
|
4.8
|
4.0
|
3.3
|
2.5
|
1.6
|
1.0
|
0.6
|
0.39
|
|
(ii) 0.50...
|
12
|
12
|
10
|
9.5
|
7.9
|
6.5
|
4.9
|
3.1
|
2.0
|
1.2
|
0.78
|
|
(iii) 1.0...
|
24
|
23
|
21
|
19
|
16
|
13
|
9.9
|
6.2
|
3.9
|
2.5
|
1.6
|
|
(iv) 1.5...
|
36
|
35
|
31
|
29
|
24
|
20
|
15
|
9.3
|
5.9
|
3.7
|
2.4
|
|
(v) 2.0...
|
48
|
46
|
42
|
38
|
32
|
26
|
20
|
12
|
7.8
|
4.9
|
3.1
|
|
(vi) 2.5...
|
60
|
58
|
52
|
48
|
40
|
33
|
25
|
16
|
9.8
|
6.2
|
3.9
|
|
(vii) 3.0...
|
72
|
69
|
63
|
57
|
47
|
39
|
30
|
19
|
12
|
7.4
|
4.7
|
1 Systems may use this equation to
determine log credit between the indicated values: Log credit = (0.0397 x
(1.09757) Temp) x CT.
(3) Site-specific study.
The director may approve alternative chlorine dioxide or ozone
CT values to those listed in paragraph (N)(2) of this rule on a site-specific
basis. The director shall base this approval on a site-specific study a system
conducts that follows a protocol acceptable to the director.
(4) Ultraviolet light. Systems receive
Cryptosporidium, Giardia lamblia, and
virus treatment credits for ultraviolet
(UV) light reactors by achieving the corresponding UV dose values shown in
paragraph (N)(4)(a) of this rule. Systems shall validate and
monitor UV
reactors as described in paragraphs (N)(4)(b) and (N)(4)(c) of this rule to
demonstrate that they are achieving a particular UV dose value for treatment
credit. The U.S. EPA "Ultraviolet
Disinfection Guidance Manual for the Final
Long Term 2 Enhanced Surface
Water Treatment Rule" (November 2006), shall be used as a guide
in the technical review of plans submitted for approval of UV facilities.
The water research foundation "Guidance for
Implementing Action Spectra Correction with Medium Pressure UV Disinfection
(Web Report #4376)" shall also be used as a guide in the technical review of
plans submitted for approval of medium pressure UV reactor facilities.
Approval of plans for UV facilities may be conditioned upon requirements that
may be necessary or desirable to ensure that the system being constructed, or
of which the proposed project is a part, will be able to meet generally
accepted standards for the design, equipping and operation of UV facilities.
Systems shall keep daily operational logs used to determine monthly compliance
with the percentage of water treated under validated conditions. The
operational logs must be signed by an operator of record and kept on a form
acceptable to the director. Operational logs must be made available for review
upon request.
(a) UV dose table.
The treatment credits listed in this table are for UV light at
a wavelength of two hundred fifty-four nanometers as produced by a low pressure
mercury vapor lamp. To receive treatment credit for other lamp types, systems
shall demonstrate an equivalent germicidal dose through reactor validation
testing, as described in paragraph (N)(4)(b) of this rule. The UV dose values
in this table are applicable only to post-filter applications of UV.
UV Dose Table for Cryptosporidium, Giardia lamblia, and Virus
Inactivation Credit
|
Log credit
|
Cryptosporidium UV dose
(mJ/cm2)
|
Giardia lamblia UV dose
(mJ/cm2)
|
Virus UV dose (mJ/
cm2)
|
|
(i) 0.5...
|
1.6
|
1.5
|
39
|
|
(ii) 1.0...
|
2.5
|
2.1
|
58
|
|
(iii) 1.5...
|
3.9
|
3.0
|
79
|
|
(iv) 2.0...
|
5.8
|
5.2
|
100
|
|
(v) 2.5...
|
8.5
|
7.7
|
121
|
|
(vi) 3.0...
|
12
|
11
|
143
|
|
(vii) 3.5...
|
15
|
15
|
163
|
|
(viii) 4.0...
|
22
|
22
|
186
|
(b)
Reactor validation testing.
Systems shall use UV reactors that have undergone validation
testing to determine the operating conditions under which the reactor delivers
the UV dose required in paragraph (N)(4)(a) of this rule (i.e., validated
operating conditions). These operating conditions shall include flow rate, UV
intensity as measured by a UV sensor, and UV lamp status.
(i) When determining validated operating
conditions, systems shall account for the following factors: UV absorbance of
the water; lamp fouling and aging; measurement uncertainty of on-line sensors;
UV dose distributions arising from the velocity profiles through the reactor;
failure of UV lamps or other critical system components; and inlet and outlet
piping or channel configurations of the UV reactor.
(ii) Validation testing shall include the
following: Full scale testing of a reactor that conforms uniformly to the UV
reactors used by the system and inactivation of a test microorganism whose dose
response characteristics have been quantified with a low pressure mercury vapor
lamp.
(iii) The director may
approve an alternative approach to validation testing.
(c) Reactor monitoring.
(i) Systems shall
monitor their UV reactors
to determine if the reactors are operating within validated conditions, as
determined under paragraph (N)(4)(b) of this rule. This monitoring shall
include UV intensity as measured by a UV sensor, flow rate, lamp status, and
other parameters the
director designates based on UV reactor operation. Systems
shall verify the calibration of UV sensors and shall recalibrate sensors at
least monthly in accordance with a protocol the
director accepts. The following
parameters shall be monitored and recorded at the frequencies indicated in the
table below for each UV reactor:
|
Parameter
|
Recording Frequency
|
Required conditions for obtaining disinfection
credit.
|
|
Off-specification alarm
|
At least every 5 minutes
|
Recording shall continue until the alarm condition has
been corrected.
|
|
UV Intensity
|
At least every 4 hours
|
The UV intensity shall be greater than or equal to the
validated set point.
|
|
UVT (required only if necessary for the dose monitoring
strategy (e.g., calculated dose approach))
|
At least every 4 hours
|
The UVT shall be greater than or equal to the minimum
UVT validated.
|
|
Validated Dose
|
At least every 4 hours
|
The validated dose shall be greater than or equal to
the Dreq.
|
|
Lamp Status
|
At least every 4 hours
|
Lamps shall be energized if water is flowing through
the UV reactor.
|
|
Flow Rate
|
At least every 4 hours
|
The flow rate shall be less than or equal to the
maximum flow tested in validation.
|
|
Production Volume
|
Off-specification events and monthly
total
|
The production volume shall be recorded so the
off-specification compliance calculation can be completed.
|
|
Calibration of UV Sensors
|
At least monthly
|
Calibration shall be conducted in accordance with a
protocol acceptable to the director.
|
|
Calibration of On-line UVT Analyzer (required only if
necessary for the dose monitoring strategy (e.g., calculated dose
approach)
|
Weekly
|
Calibration must be conducted in accordance with a
protocol acceptable to the director.
|
(ii)
To receive treatment credit for UV light, systems shall treat at least
ninety-five per cent of the water delivered to the public during each month by
UV reactors operating within validated conditions for the required UV dose, as
described in paragraphs (N)(4)(a) and (N)(4) (b) of this rule. Systems shall
demonstrate compliance with this condition by the monitoring required under
paragraph (N)(4)(c)(i) of this rule.
[This rule references the U.S. EPA "Membrane Guidance Manual
for the Final Long Term 2 Enhanced Surface Water Treatment Rule," issued
November 2005. This document is available from the "U.S. EPA Office of Ground
Water and Drinking Water, Ariel Rios Building, 1200 Pennsylvania Ave, NW,
Washington, DC 20460-0003, (202) 564-3750." A copy may also be obtained from
www.epa.gov/safewater/disinfection/lt2/compliance.html.]
[This rule references the U.S. EPA "Ultraviolet Disinfection
Guidance Manual for Final Long Term 2 Enhanced Surface Water Treatment Rule,"
issued November 2006. This document is available from the "U.S. EPA Office of
Ground Water and Drinking Water, Ariel Rios Building, 1200 Pennsylvania Ave,
NW, Washington, DC 20460-0003, (202) 564- 3750." A copy may also be obtained
from www.epa.gov/safewater/disinfection/lt2/compliance.html.]
