LT2 Toolbox Options

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LT2 Toolbox Options

• Kentucky Water and Wastewater Operators
  Association
• March 22, 2005

BY Julie W. Roney Technical Assistance and
Outreach Drinking Water Branch Division of Water
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Getting to the LT2 Toolbox

• If required, conduct Crypto sampling as
  prescribed by the final rule
• 2 options
• Grandfather data
• Guidance on DWB web site on how to grandfather
  data
• US EPA web site has document on grandfathering
  data
• Conduct monitoring after rule is final

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Getting to the LT2 Toolbox

• Once all Crypto monitoring is done, determine
  average Crypto level
• Look at Bin Classification Table and determine
  Bin
• lt0.075 oocysts per L Bin 1
• 0.075 to lt 1.0 oocysts per L Bin 2
• 1.0 to lt3.0 oocysts per L Bin 3
• 3.0 or greater oocysts per L Bin 4

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Getting to the LT2 Toolbox

• The Bin Classification determines if additional
  treatment is necessary (beyond 3 log given in LT2
  for meeting turbidity requirements)
• Bin 1 No additional treatment
• Bin 2 1 log additional treatment
• Bin 3 2 log additional treatment
• Bin 4 2.5 log additional treatment
• If in Bin 3 or 4, must achieve 1 log of the
  required additional logs of treatment with one or
  a combination of bag filters, bank filtration,
  cartridge filters, chlorine dioxide, membranes,
  ozone and/or UV

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Getting to the LT2 Toolbox

• Must use one or more of the options (when
  allowed) in what is known as the Toolbox to
  meet the additional log(s) of Crypto
  removal/inactivation
• NOTE that the requirement of the Bins is for
  additional treatment through
• Removal
• Inactivation

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Toolbox Categories

• Removal Options
• Source Water/Watershed
• Pre-filtration
• Treatment Performance
• Additional Filtration
• Inactivation

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Source Water/Watershed Options

• Watershed Control Program
• Alternative Source/Intake Management

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Source Water/Watershed Options

• Watershed control
• 0.5 log credit for State-approved program
  comprised of EPA specified elements
• Notify state within 1 year of completing Crypto
  monitoring
• Submit a initial proposed watershed control plan
  and a request for approval for 0.5 log credit
• Done within 2 years after completing Crypto
  monitoring
• State approves, rejects, conditionally approves

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Source Water/Watershed Options

• Watershed control
• Components of watershed control program
• Analysis of vulnerability of upstream watershed
  to Crypto
• Watershed hydrogeology
• Identification of area of influence outside of
  which there are no Crypto or fecal coliform
  sources
• Identification of potential sources of Crypto or
  fecal coliforms
• Relative impact of those sources on water
  systems source water
• Estimate of seasonal variation in contamination
• Analysis of measures that could control such
  contamination
• Plan of action with goals and priorities
• Water system plan is valid until next round of
  Crypto sampling

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Source Water/Watershed Options

• Watershed control
• Submit annual watershed control status report to
  state
• Conduct annual watershed sanitary survey and
  submit report to state

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Source Water/Watershed Options

• Alternate source
• Must have been monitored for Crypto just as
  current source
• Different source
• Different intake level

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Pre-Filtration Options

• Pre-sedimentation Basin with Coagulant Addition
• Two-stage Lime Softening
• Bank Filtration

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Pre-filtration Options

• Pre-sedimentation Basin with Coagulant Addition
• Existing pre-sedimentation basins cannot be used
  for this option and if used, the initial Crypto
  monitoring must occur after these basins
• New pre-sedimentation basin criteria for 0.5 log
  credit
• Basin must be in continuous service
• System must continuously add a coagulant to the
  basin
• Basin influent and effluent turbidity must be
  monitored at least daily
• Monthly demonstrate a 0.5 log reduction in
  turbidity through basin

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Pre-filtration Options

• Two-stage lime softening
• 0.5 log credit provided
• There is a second clarification step between the
  primary clarifier and filtration
• This step is operated continuously
• All raw water is treated through this step
• Coagulant must be present in both clarifiers
• Excess lime
• Excess magnesium hydroxide

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Pre-filtration Options

• Bank Infiltration
• New bank filtration that serves as pretreatment
• Existing bank filtration may not claim this
  creditsource water monitoring for Crypto bin
  classification must occur after existing bank
  infiltration
• Log credit provided
• 0.5 log if groundwater flow path is 25 feet
• 1.0 log if groundwater flow path is 50 feet
• Only horizontal and vertical wells are eligible
• Only wells in granular aquifers are eligible
• Granular aquifer comprised of sand, clay, silt,
  rock fragments, pebbles or larger particles and
  minor cement
• Must be unconsolidated material
• System must characterize the well aquifer
  properties to include core samples
• If unconsolidated aquifer, petition the state
• Turbidity measurements from each wellhead at
  least every 4 hours that bank filtration is in
  operation

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Treatment Performance Options

• Combined Filter Performance
• Individual Filter Performance
• Demonstration of Performance

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Treatment Performance Options

• Combined Filter Performance
• Applicable to conventional or direct filtration
• 0.5 log credit for any month if demonstrated that
  the combined filter effluent levels are less than
  or equal to 0.15 NTU in at least 95 of the
  4-hour samples taken for compliance purposes

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Treatment Performance Options

• Individual Filter Performance
• Applicable to conventional or direct filtration
• 1.0 log credit for any month if demonstrated that
  the each individual filter effluent level is
• Less than or equal to 0.1 NTU in at least 95 of
  the maximum daily values recorded at each filter
  each month, excluding the 15 minute period
  following return to service after a backwash
• No individual filter may exceed 0.3 NTU in 2
  consecutive readings taken 15 minutes apart
• NOTE Cannot claim credit for both CFE and IFE
  performance options

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Treatment Performance Options

• Demonstration of performance
• Demonstration must follow state-approved
  protocols
• Must demonstrate that Crypto removal efficiency
  is greater than any presumptive credit given in
  the bin classification table (greater than 2.5 if
  convention/direct) or the toolbox (greater than
  2.5 log)
• System must be able to meet this removal credit
  continuously
• State generated report with ongoing monitoring or
  performance requirements as well as reporting
  requirements
• If state determines that the removal efficiency
  is less than any maximum as determined above, it
  can assign that log removal
• NOTE A system cannot use any credit for a
  toolbox option if it is used in the demonstration
  of performance

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Additional Filtration Options

• Bag Filters
• Cartridge Filters
• Membrane Filtration
• Second Stage Filtration
• Slow Sand Filters

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Additional Filtration Options

• Bag and Cartridge Filters
• Removal Credits
• 1 log credit for bag filtersmust demonstrate a 2
  log or greater removal of Crypto
• 2 log credit for cartridge filtersmust
  demonstrate a 3 log or greater removal of Crypto
• Log removals determined by challenge testing
  under criteria in LT2 regulation
• If a previously installed bag or cartridge filter
  is modified, additional challenge testing shall
  be conducted

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Additional Filtration Options

• Membrane Filtration
• Awarded removal credit awarded for the removal
  efficiency demonstrated
• During the challenge test or
• Verified by the direct integrity test applied to
  the system
• Challenge testing using Crypto or a surrogate
  must be conducted under representative hydraulic
  conditions according to LT2 regulations with
  results submitted to the state

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Additional Filtration Options

• Membrane Filtration
• Direct integrity testing must be applied to each
  individual membrane unit and must demonstrate a
  removal efficiency equal to or greater than that
  awarded to the filtration process
• Applied pressure or vacuum
• Particulate or molecular marker
• Establish a control limit
• Conducted at least once a day that the membrane
  unit is in service
• Indirect integrity testing
• Must be continuous on each membrane unit
• Must include continuous turbidity monitoring
  every 15 minutes

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Additional Filtration Options

• Second Stage Filtration
• 0.5 log credit for a separate second stage
  filtration process consisting of
• Rapid sand
• Dual media
• GAC
• Other fine grain media
• To be eligible, the first stage of filtration
  must be preceded by coagulation and both
  filtration stages must treat 100 of the plant
  flow
• NOTE A GAC cap on a single stage of filtration
  is not eligible for this credit

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Additional Filtration Options

• Slow Sand Filtration
• 2.5 log credit for second separate slow sand
  filtration step provided
• All plant flow is treated by both filtration
  processes
• No disinfectant residual is present in the
  influent water to the slow sand filtration process

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Inactivation (Disinfection) Options

• Chlorine Dioxide
• Ozone
• Ultraviolet Disinfection

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Inactivation (Disinfection) Options

• Chlorine Dioxide
• Log inactivation credit based on
• Compliance with the C-T table in the LT2
  regulation or
• Site-specific inactivation study to meet a
  specified Crypto log inactivation based on a
  state-approved protocol
• Alternate C-T must be approved by the state

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Inactivation (Disinfection) Options

• Ozone
• Log inactivation credit based on
• Compliance with the C-T table in the LT2
  regulation or
• Site-specific inactivation study to meet a
  specified Crypto log inactivation based on a
  state-approved protocol
• Alternate C-T must be approved by the state

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Inactivation (Disinfection) Options

• Ultraviolet Disinfection
• Can use for Giardia, Crypto and virus
  inactivation credit
• LT2 UV dose table based on wavelength of 254 nm
  produced by a low pressure mercury vapor lamp
• Can apply to other UV reactors through reactor
  validation testing
• UV Dose table only applicable to post-filtration
  applications
• UV reactors must be monitored to demonstrate that
  they are within the range of conditions set
  during validation
• UV intensity
• Flow rate
• Lamp outage
• Others set by state
• Must verify calibration of any monitors

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Questions?? Comments??

• Julie W. Roney, Supervisor
• Technical Assistance and Outreach Section
• Drinking Water Branch
• 502/564-3410 extension 535
• Julie.Roney_at_ky.gov
• www.water.ky.gov/dw