Ohio Admin. Code 3745-81-77 - Treatment techniques for control of disinfection byproduct (DBP) precursors
(A) Surface water community and nontransient
noncommunity public water systems using conventional filtration treatment shall
operate with enhanced coagulation or enhanced softening to achieve the TOC per
cent removal levels specified in paragraph (F) of this rule unless the system
meets at least one of the alternative compliance criteria listed in paragraph
(D) or (E) of this rule.
(B)
Surface water systems using conventional filtration treatment shall comply with
the following monitoring requirements for disinfection byproduct precursors
(DBPP).
(1) Routine monthly monitoring:
public water systems using surface water as a source which use conventional
filtration treatment shall monitor each treatment plant for TOC no later than
the point of combined filter effluent turbidity monitoring and representative
of the treated water. All public water systems required to monitor under this
paragraph shall also monitor for TOC in the source water prior to any treatment
at the same time as monitoring for TOC in the treated water. These samples
(source water and treated water) are referred to as paired samples. At the same
time as the source water sample is taken, all systems shall monitor for
alkalinity in the source water prior to any treatment. Public water systems
shall take one paired sample and one source water alkalinity sample every
thirty days per plant at a time representative of normal operating conditions
and influent water quality. The thirty day monitoring frequency may be extended
or reduced by three days to allow for unplanned circumstances that prevent
monitoring precisely thirty days apart, as long as the samples are collected
during each calendar month.
(2)
Reduced quarterly monitoring: public water systems using surface water as a
source with an average treated water TOC of less than 2.0 mg/l for two
consecutive years, or less than 1.0 mg/l for one year, may reduce monitoring
for both TOC and alkalinity to one paired sample and one source water
alkalinity sample per plant every ninety days. The ninety day monitoring
frequency may be extended or reduced by five days to allow for unplanned
circumstances that prevent monitoring precisely ninety days apart, as long as
the samples are collected during each calendar quarter. The public water system
must revert to routine monitoring in the month following the quarter when the
running annual average treated water TOC >2.0 mg/l.
(C) Public water
systems may begin monitoring twelve months prior to the compliance date for the
system, to determine whether step 1 TOC removals can be met. This monitoring is
not required and failure to monitor during this period is not a violation.
However, any public water system that does not monitor during this period, and
then determines in the first twelve months after the compliance date that it is
not able to meet the step 1 requirements in paragraph (F)(2) of this rule and
must apply for alternate minimum TOC removal (step 2) requirements, is not
eligible for retroactive approval of alternate minimum TOC removal (step 2)
requirements as allowed by paragraph (F)(3) of this rule and is in violation of
the treatment technique for TOC removal of this rule. Public water systems may
apply for alternate minimum TOC removal (step 2) requirements any time after
the compliance date.
(D)
Alternative compliance criteria for enhanced coagulation and enhanced softening
systems. Surface water systems using conventional filtration treatment may use
one or more of the alternative compliance criteria in paragraphs (D)(1) to
(D)(7) of this rule to comply with this rule in lieu of complying with
paragraph (F) of this rule. Public water systems must still comply with the
monitoring requirements of paragraph (B) of this rule.
(1) The system's source water TOC level,
measured according to rule
3745-81-27
of the Administrative Code, is less than 2.0 mg/l, calculated quarterly as a
running annual average.
(2) The
system's treated water TOC level, measured according to rule
3745-81-27
of the Administrative Code, is less than 2.0 mg/l, calculated quarterly as a
running annual average.
(3) The
system's source water TOC level, measured according to rule
3745-81-27
of the Administrative Code, is less than 4.0 mg/l, calculated quarterly as a
running annual average; the source water alkalinity, measured according to rule
3745-81-27
of the Administrative Code, is greater than 60.0 mg/l (as
CaCO3), calculated quarterly as a running annual average
and the TTHM and HAA5 running annual averages are no greater than 0.040 mg/l
and 0.030 mg/l, respectively.
(4)
The system's source water TOC level, measured according to rule
3745-81-27
of the Administrative Code, is less than 4.0 mg/l, calculated quarterly as a
running annual average; the source water alkalinity, measured according to rule
3745-81-27
of the Administrative Code, is greater than 60.0 mg/l (as
CaCO3), calculated quarterly as a running annual average
and the system has made a clear and irrevocable financial commitment to use
technologies that will limit the levels of TTHMs and HAA5 to no more than 0.040
mg/l and 0.030 mg/l, respectively. Systems must submit evidence of a clear and
irrevocable financial commitment, in addition to a schedule containing
milestones and periodic progress reports for installation and operation of
appropriate technologies, to the director for approval. Failure to install and
operate these technologies by the date in the approved schedule will constitute
a violation of the Administrative Code primary drinking water regulations for
control of disinfection byproduct precursors.
(5) The TTHM and HAA5 running annual averages
are no greater than 0.040 mg/l and 0.030 mg/l, respectively, and the system
uses only chlorine for primary disinfection and maintenance of a residual in
the distribution system.
(6) The
system's source water SUVA, prior to any treatment and measured monthly
according to of rule
3745-81-27
of the Administrative Code, is less than or equal to 2.0 l/mg-m, calculated
quarterly as a running annual average.
(7) The system's finished water SUVA,
measured monthly according to rule
3745-81-27
of the Administrative Code, is less than or equal to 2.0 l/mg-m, calculated
quarterly as a running annual average.
(E) Additional alternative compliance
criteria for softening systems. Systems practicing enhanced softening that
cannot achieve the TOC removals required by paragraph (F)(2) of this rule may
use the alternative compliance criteria in paragraph (E)(1) or (E)(2) of this
rule in lieu of complying with paragraph (F) of this rule. Systems must still
comply with monitoring requirements in paragraph (B) of this rule.
(1) Softening that results in lowering the
treated water alkalinity to less than 60.0 mg/l (as
CaCO3), measured monthly according to rule
3745-81-27
of the Administrative Code and calculated quarterly as a running annual
average.
(2) Softening that results
in removing at least 10.0 mg/l of magnesium hardness (as
CaCO3), measured monthly according to paragraph
(C)(4)(c) of rule
3745-81-27
of the Administrative Code and calculated quarterly as an annual running
average.
(F) Enhanced
coagulation and enhanced softening performance requirements.
(1) Public water systems must achieve the per
cent reduction of TOC specified in paragraph (F)(2) of this rule between the
source water and the combined filter effluent, unless the director approves a
system's request for alternate minimum TOC removal (step 2) requirements under
paragraph (F)(3) of this rule.
(2)
Required step 1 TOC reductions, indicated in the following table, are based
upon specified source water parameters measured according to rule
3745-81-27
of the Administrative Code. Systems practicing softening are required to meet
the step 1 TOC reductions in the far-right column(source water alkalinity
>120 mg/l) for the specified source water TOC:
Step 1 required removal of TOC by enhanced coagulation and enhanced softening for surface water systems using conventional treatment1,2
See Table at http://www.registerofohio.state.oh.us/pdfs/3745/0/81/3745-81-77_PH_FF_A_RU_20091204_0807.pdf
(3) Surface water conventional
treatment systems that cannot achieve the step 1 TOC removals required by
paragraph (F)(2) of this rule due to water quality parameters or operational
constraints shall apply to the director, within three months of failure to
achieve the TOC removals required by paragraph (F)(2) of this rule, for
approval of alternative minimum TOC removal (step 2) requirements submitted by
the system. If the director approves the alternative minimum TOC removal (step
2) requirements, the director may make those requirements retroactive for the
purposes of determining compliance. Until the director approves the alternate
minimum TOC removal (step 2) requirements, the system must meet the step 1 TOC
removals contained in paragraph (F)(2) of this rule.
(4) Alternate minimum TOC removal (step 2)
requirements. Applications made to the director by enhanced coagulation systems
for approval of alternative minimum TOC removal (step 2) requirements under
paragraph (F)(3) of this rule shall include, at a minimum, results of bench- or
pilot-scale testing conducted under paragraphs (F)(6) to (F)(9) of this rule.
The submitted bench- or pilot-scale testing shall be used to determine the
alternate enhanced coagulation level.
(5) Alternate enhanced coagulation level is
defined as coagulation at a coagulant dose and pH as determined by the method
described in paragraphs (F)(6) to (F)(9) of this rule such that an incremental
addition of 10.0 mg/l of alum (or equivalent amount of ferric salt) results in
a TOC removal of <0.3 mg/l. The per cent removal of
TOC at this point on the "TOC removal versus coagulant dose" curve is then
defined as the minimum TOC removal required for the system. Once approved by
the director, this minimum requirement supersedes the minimum TOC removal
required by the table in paragraph (F)(2) of this rule. This requirement will
be effective until such time as the director approves a new value based on the
results of a new bench- or pilot-scale test. Failure to achieve alternative
minimum TOC removal levels as set by the director is a violation of the
Administrative Code primary drinking water regulations for control of
disinfection byproduct precursors.
(6) Bench- or pilot-scale testing of enhanced
coagulation must be conducted by using representative water samples and adding
10.0 mg/l increments of alum (or equivalent amounts of ferric salt) until the
pH is reduced to a level less than or equal to the enhanced coagulation step 2
target pH shown in the following table:
See Table at http://www.registerofohio.state.oh.us/pdfs/3745/0/81/3745-81-77_PH_FF_A_RU_20091204_0807.pdf
(7) For waters with alkalinities
of less than 60.0 mg/l for which addition of small amounts of alum or
equivalent addition of iron coagulant drives the pH below 5.5 before
significant TOC removal occurs, the system must add necessary chemicals to
maintain the pH between 5.3 and 5.7 in samples until the TOC removal of 0.3
mg/l per 10.0 mg/l alum added (or equivalent addition of iron coagulant) is
reached.
(8) The system may operate
at any coagulant dose or pH necessary (consistent with other state primary
drinking water regulations) to achieve the minimum TOC per cent removal
approved under paragraph (F)(3) of this rule.
(9) If the TOC removal is consistently less
than 0.3 mg/l of TOC per 10.0 mg/l of incremental alum dose at all dosages of
alum (or equivalent addition of iron coagulant), the water is deemed to contain
TOC not amenable to enhanced coagulation. The system may then apply to the
director for a waiver of enhanced coagulation requirements.
(G) Compliance calculations:
surface water systems other than those identified in paragraph (D) or (E) of
this rule shall comply with requirements contained in paragraph (F)(2) or
(F)(3) of this rule. Systems shall calculate compliance quarterly, beginning
after the system has collected twelve months of data, by determining a running
annual average using the following method:
(1) Determine actual monthly TOC per cent
removal. This is equal to: ( 1.0 - (treated water TOC/source water TOC)) x
100.0.
(2) Determine the required
monthly TOC per cent removal (from either the table in paragraph (F)(2) of this
rule or from paragraph (F)(3) of this rule).
(3) Divide the value determined according to
paragraph (G)(1) of this rule by the value determined according to paragraph
(G)(2) of this rule.
(4) Add
together the results of paragraph (G)(3) of this rule for the last twelve
months and divide by twelve.
(5) If
the value calculated in paragraph (G)(4) of this rule is less than 1.00, the
system is not in compliance with the TOC per cent removal requirements.
(6) Systems may use the provisions
in paragraphs (G)(7) to (G)(11) of this rule in lieu of the calculations in
paragraphs (G)(1) to (G)(5) of this rule to determine compliance with TOC per
cent removal requirements.
(7) In
any month that the system's treated or source water TOC level, measured
according to rule
3745-81-27
of the Administrative Code, is less than 2.0 mg/l, the system may assign a
monthly value of 1.0 (in lieu of the value calculated in paragraph (G)(3) of
this rule).
(8) In any month that a
system practicing softening removes at least 10.0 mg/l of magnesium hardness
(as CaCO3), the system may assign a monthly value of 1.0
(in lieu of the value calculated in paragraph (G)(3) of this rule).
(9) In any month that the system's source
water SUVA, prior to any treatment and measured according to rule
3745-81-27
of the Administrative Code, is<2.0 l/mg-m, the
system may assign a monthly value of 1.0 (in lieu of the value calculated in
paragraph (G)(3) of this rule).
(10) In any month that the system's finished
water SUVA, measured according to rule
3745-81-27
of the Administrative Code, is<2.0 l/mg-m, the
system may assign a monthly value of 1.0 (in lieu of the value calculated in
paragraph (G)(3) of this rule).
(11) In any month that a system practicing
enhanced softening lowers alkalinity below 60.0 mg/l (as
CaCO3), the system may assign a monthly value of 1.0 (in
lieu of the value calculated in paragraph (G)(3) of this rule).
(12) Surface water systems using conventional
treatment may also comply with the requirements of this rule by meeting the
criteria in paragraph (D) or (E) of this rule.
(H) Treatment technique requirements for DBP
precursors. The director identifies the following as treatment techniques to
control the level of disinfection byproduct precursors in drinking water
treatment and distribution systems: for surface water systems using
conventional treatment, enhanced coagulation or enhanced softening.
(I) Each public water system required to
monitor under this rule shall develop and implement a monitoring plan. The
public water system shall maintain the plan and make it available for
inspection by the director and the general public no later than thirty days
following the applicable compliance dates in this rule. All surface water
systems serving more than three thousand three hundred people shall submit a
copy of the monitoring plan to the director no later than the date of the first
report required under paragraph (G) of rule
3745-81-75
of the Administrative Code. The director may also require any other public
water system to submit such a plan. After review, the director may require
changes in any plan elements to ensure monitoring will be adequate for required
compliance determinations. The public water system shall modify the plan as
required by the director. The plan shall include how the public water system
will calculate compliance with the treatment technique for disinfection
byproduct precursors. Failure to sample according to the monitoring plans is
monitoring violation.
Notes
Promulgated Under: 119.03
Statutory Authority: 6109.04
Rule Amplifies: 6109.04
Prior Effective Dates: 01/01/2002, 01/01/2004, 01/01/2010
Promulgated Under: 119.03
Statutory Authority: 6109.04
Rule Amplifies: 6109.03, 6109.04
Prior Effective Dates: 01/01/02, 01/01/04
Promulgated Under: 119.03
Statutory Authority: 6109.04
Rule Amplifies: 6109.04
Prior Effective Dates: 01/01/02, 01/01/04
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