Total Coliform Rule TCR

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Total Coliform Rule (TCR)
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General

• The purpose of the TCR is to protect the water
  system from microbial contamination
• TCR requires the water system to monitor for
  total and fecal coliform bacteria.
• TCR applies to all community and non-community
  water systems

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What is a coliform?

• A group of bacteria that include both pathogenic
  and non-pathogen species
• Gram negative, spore-forming rod shaped bacteria
  that ferments lactose at 35oC
• Indicator organism
• Always present in fecal contamination
• More persistent in water than pathogenic bacteria

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Definitions

• Bacteria
• Coliform Bacteria
• Fecal Coliform / E. coli
• Pathogenic Bacteria
• Routine Sample
• Repeat Sample
• Replacement Sample
• Other Sample

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TCR Test Methods

• Test volume is at least 100 mL
• Test results are reported as either Present or
  Absent per 100 mL sample
• Bacterial enumeration (counting) is not required

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TCR Approved Test Methods
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Who can take TCR samples?

• Certified water treatment / distribution
  operators
• Persons trained to collect samples by DHS / LPA
• A certified laboratory technician

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TCR Requirements

• Develop a sample siting plan (update at least
  every 10 years)
• Collect routine, repeat and replacement samples
  as required by TCR for your water system
• Notify DHS or your LPA (County Health Department)
  when there is an increase in coliform bacteria
• Comply with the total coliform MCL

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Other Coliform Sampling

• In addition to following your sample siting plan,
  take additional bacteriological analyses when
• After construction or repair of wells (following
  disinfection, but before return to service
• After main installation or repair
• After construction or repair of storage
  facilities
• Whenever system pressure drops below 5 psi
• These special samples are not used to compute MCL
  compliance

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TCR Sample Siting Plan

• Location of routine samples
• Chose sites that are representative of the
  distribution system including
• All pressure zones
• Each water source
• Each distribution reservoir
• Sites should be rotated if representative sites
  exceeds the number of samples taken each month.

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Sample Siting Plans

• It is strongly recommended that locations repeat
  sample sites be included in the sample siting plan

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Tips for Selecting the Best Sample Sites

• Accessible
• Above big dog height or otherwise protected
• Consider dedicated sample taps
• No leaking valves or packings
• Good flow control
• No bushes or vegetation
• Can be flamed or cleaned
• Can be flushed vigorously without causing
  problems with the homeowner

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Repeat Sample Site Selection

• 1st Repeat site is the original location
• Site 2 3 must be within 5 service connections
  upstream and 5 service connections downstream
  (further from source)
• Chose repeat sites using the same criteria as
  routine sites
• System taking less than 5 routine samples per
  month must take a 4th repeat sample at a location
  acceptable to DHS/LPA

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Routine Sampling

• Number of routine samples/month determined by
  system size
• Minimum frequency of sampling is one per month
  for small systems (25 to 1000 population
• Samples shall be collected at regular intervals
  throughout the month

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Repeat Samples

• When any routine, repeat or replacement sample is
  total coliform positive the water system shall
• Collect a repeat sample set within 24 hours of
  being informed of the positive sample
• Repeat sample set is required for each positive
  routine, repeat or replacement sample

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Repeat Sample Set

• Three samples (small systems take 4 repeat
  samples)
• One sample from the original total coliform
  sample location
• Other repeat samples shall be taken within five
  service connections upstream or downstream of
  original location.

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Significant Rise in Bacterial Count

• Significant rise in bacterial count occurs when
• System has a positive for fecal or E.coli
• System fails the total coliform MCL

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Significant Rise in Bacterial Count

• When a system has a significant rise in bacterial
  count it must
• Contact DHS/LPA by the end of the day (no later
  than 24 hours)
• Submit a review of water system conditions that
  could contribute or cause the problem
• Implement emergency notification plan as directed
  by DHS/LPA

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Total Coliform MCL

• All routine, repeat and replacement samples taken
  in a calendar month are used to calculate MCL
  compliance
• Special samples (after maintenance samples) are
  not used to determine MCL compliance
• Special samples must be properly labled

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Acute Coliform MCL

• An Acute MCL violation occurs when
• Any repeat sample is fecal coliform / E.coli
  positive, or
• Any repeat sample following a routine fecal
  positive is total coliform positive

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Total Coliform MCL

• Systems in violation of the Total Coliform MCL
  shall
• Notify DHS/LPA within 24 hours
• Notify consumers of water system