The use of E' coli indicator bacteria to assess waters for swimming uses in VT

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The use of E. coli indicator bacteria to assess
waters for swimming uses in VT

• Neil Kamman
• VT Department of Environmental Conservation
• Lake Morey Resort, Fairlee, VT
• May 2006

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Vermont supports a multi-pronged swim-water
monitoring approach

• VTs water quality standard for E. coli
• Vermonts assessment approach
• Town Health Officer beach testing
• Municipal beach monitoring
• VT Forests, Parks, and Recreation monitoring
• LaRosa Partnership program
• Resources for monitoring provided by VTDEC

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The VT E. coli WQ Standard

• VTs WQ standard is 77 E. coli /100ml in Class B
  waters for all management types
• VTs WQ standard for Class A waters is even lower
  (33 s.s.m., 18 geomean)
• This is the most stringent standard suite in the
  U.S .

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What this means

• Major studies in the early 80s and recently
  developed E. coli standards by relating observed
  illness rates to varying observed E. coli levels
• The minimum detectable illness rate was 8
  swimmers per 1,000 over the course of the summer,
  based on a geometric mean of 126 /100ml, or
  single sample maximum values of 235.
• A geometric mean is designed for data that are
  log-normally distributed, like E. coli

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VTs water quality criterion in relation to EPA
recommendation
EPA recommended criterion
VT criterion 77
EPA allowable range
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VT Department of Health Town Health Officers

• VTDOH has published swim beach safety guidelines
  based on E. coli that relate to the VT standard
  of 77.
• All towns may, thru the Town Health Officers, to
  monitor their informal but well-known swim holes.
• Samples are delivered to DOH lab by mail, with
  results returned to officers as safe to swim or
  not safe to swim
• This will be discussed in more detail by Dr.
  Bress during this meeting.

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Monitoring at VT State Parks

• VT Dept Forests, Parks and Rec. monitors State
  Park beaches weekly at 24 high-use VT lakes (gt30
  park beaches).
• Closure occurs when E. coli exceeds 77, which
  prompts a retest (VTDOH recommendation).
• gt95 of retests come back lt77.
• Closures at the magic 77 can create inaccurate
  public opinion about beach WQ in certain State
  Parks.
• FPR has in-house materials to report to
  individual park operators regarding the magnitude
  of the closures

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Monitoring at VT State Parks

• VTDEC tracks FRP data over time, analyzes trends,
  reports to EPA
• Data archived electronically since 1977
• Geomeans for individual parks range from 1 to 39
  E. coli /100ml
• Only four parks display regular violations of
  VTs standard.

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Monitoring at VT State Parks
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Municipal beaches monitoring

• Several towns regularly monitor their municipally
  owned/operated beaches using contract labs
• Burlington Parks
• Colchester
• Bennington
• Others?
• Burlington and Colchester data are available
  online via websites
• Closures are consistent w/ VTDOH recommendation

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The LaRosa Environmental Laboratory Partnership

• Novel partnership between VTDEC and citizen
  organizations to enable monitoring of E. coli and
  other WQ parameters.
• Competitive, RFP-based grant program whereby DEC
  allocates lab services to small / underfunded
  citizen organizations
• 24 citizen watershed organizations have
  participated to date

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The LaRosa Environmental Laboratory Partnership

• Projects adhere to QAPP requirements and to VTDEC
  guidance for E. coli sampling
• Projects enable citizen groups to look into and
  address problems in their watersheds

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The LaRosa Environmental Laboratory Partnership
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VTDEC Resources for Citizens

• VT is not a Beach Act State
• VT nonetheless provides resources and/or partners
  with other groups for swim water testing.
• VT routinely consults with groups interested in
  initiating swim water and other waterbody E. coli
  testing
• VT would like to enhance reporting capabilities
  (e.g., website or hotline), but is limited by
  available funding

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VTDEC Resources for Citizens
http//www.vtwaterquality.org/htm/wq_monitoring.ht
m
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For more information
Neil Kamman VT Department of Environmental
Conservation 103 S Main 10N Waterbury VT
05671-0408 802 241-3795 neil.kamman_at_state.vt.us