DNA Fingerprinting of Bacteria Sources in the Tualatin Subbasin

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DNA Fingerprinting of Bacteria Sources in the
Tualatin Sub-basin

• Jan Miller
• Clean Water Services
• ACWA Stormwater Committee
• November 2005

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Background

• 2001 Tualatin Sub-basin Total Maximum Daily Load
  (TMDL) established Wasteload Allocations (WLA)
  for bacteria in stormwater
• Clean Water Services needs to develop Best
  Management Practices (BMPs) to reduce bacteria in
  stormwater to meet its Wasteload Allocations

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Bacteria TMDL

• Addresses Public Health Issues
• E. coli is the indicator organism
• It is not a pathogen
• Indicates possible presence of pathogens
• Bacteria such as Salmonella and Shigella
• Protozoa such as Giaradia or Cryptosporidia
• Viruses

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Wasteload Allocations

• Summer Levels for Stormwater
• 3,000 to 12,000 E. coli per 100 mLs depending on
  the subbasin
• Winter Levels for Stormwater
• 700 to 11,000 E. coli per 100 mLs depending on
  the subbasin
• All other times in summer and winter
• 406 E. coli per 100 mLs

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Bacteria Loads Compared to WLASpatially Averaged
by PLOAD
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E.coli levels in Stormwater for 2000 to 2005
Wasteload Allocations
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E. coli values from 2000 and 2005Stream Study
Sites
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Bacteria BMPs

• Connect Septic Systems to Sanitary Systems
• Actively manage pet waste
• Minimize the impact of Hobby Farms
• Limit Duck and Goose Waste
• Clean up illegal dump sites

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Need Change in Public Behavior

• Many of the BMPs require behavior changes by the
  public
• Public needs proof their activities are causing
  problems
• Thanks to court cases and CSI-style programs -
  DNA is accepted as proof by the public

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Microbial Source Tracking (MST)

• Institute for Environmental Health
• Formerly University of Washington
• Ribosomal RNA typing method
• Cost for typing
• DEQ 319h Grant 41,723 in 2002
• Clean Water Services 40,000
• Cost for sampling and E. coli isolation
• Clean Water Services 11,000
• Urban area of Tualatin Sub-basin

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Sampling Methodology

• Sites
• 5 Stream Sites representing areas of potential
  concern
• 3 Stormwater Sites
• 2 Duplicates (one stream and one stormwater)
• Weather Conditions
• Summer Dry period
• Summer Storm
• Winter Dry Period
• Winter Storm

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Want 100 Isolates for Statistical Reliability

• Each site - 5 samples collected per event
• Each sample - 3 E.coli isolates tested
• Resulted in 15 isolates per event
• 6 Stormwater Events or 7 Stream Events
• Results in 90 to 105 isolates per site

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Sites Sampled

• Stream Sites
• Residential Area Septic Tank Area
• Residential Area High Dog Population
• Residential Area Older Urban
• Down stream of a pond Duck Feeding
• Residential area Mixed Urban
• Stormwater
• Commercial Parking Lot
• New Residential Area
• Water Quality Facility Effluent (Vegetated Pond)

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Distribution and Grouping of Sources
Additional Sources Feline 13 Unknown 85
Source ID Example Using Canine Dog means
dog Coyote means coyote Canine means the DNA
type is shared between dog, coyote, wolf, fox etc.
Total Isolates 924
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All Sites All Events(No Duplicates)
924 Isolates
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Individual Sites
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Stream - Septic Tank Area
134 Isolates
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Stream - High Dog Population
125 Isolates
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Stream - Older Urban
131 Isolates
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Stream - Duck Feeding
133 Isolates
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Stream Duck FeedingDuplicates
Sample
Duplicate
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Stream - Mixed Urban
130 Isolates
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Stormwater Commercial Parking Lot
79 Isolates
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Stormwater New Residential Area
96 Isolates
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Stormwater New Residential Area Duplicates
Sample
Duplicate
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Stormwater Water Quality Facility Effluent
96 Isolates
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Compare Percentages for each Site with by Key
Sources
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Not a lot of variation between sites for each
source
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Evaluate Stream Samples Only
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Stream Bacteria Levels During Study
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Stream Bacteria Sources All Sites
653 Isolates
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Stream Bacteria Primary SourcesPercentage By
Weather Condition
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Evaluate Stormwater Samples Only
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Stormwater Runoff Bacteria Levels During Study
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Stormwater Bacteria Sources All Sites
271 Isolates
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Stormwater Bacteria from Primary
SourcesPercentage by Weather Condition
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Compare Results with Other Studies
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Comparison to Other StudiesPercentage by Type
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What Does It All Mean

• Diverse Set of Sites
• Similar Distribution of Sources
• Different Event Types
• Similar Distribution of Sources
• Different Studies
• Similar Distribution of Sources

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Relationship to Wasteload Allocations

• Provides evidence that humans are not a dominant
  source of bacteria in streams
• The importance of this is a political issue
• Provides evidence that human activities are
  resulting in increased bacteria in streams
• No obvious solution indicated
• Many individual actions
• Too much variability to predict percent reduction
  with combinations of actions

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Public Education

• Some things will be a difficult sell
• The biggest problem Birds
• May get some support for signs that ask people
  not to feed the ducks and geese
• May get some support for changes in landscaping
  to discourage ducks and geese
• But
• The public likes ducks and geese
• They like other types of birds even more!

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Public Education Creativity

• First Effort using this study
• City of Tigard
• Carla Staedter

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Holy Dog Poop Batman!!!!

• How much dog poop is natural
• Given that the wolf is the ancestor of dogs
• How many wolves can the Tualatin Sub-basin
  support?
• 70 wolves
• There are 80,000 dogs in the Tualatin Sub-basin
• That leaves 79,930 dogs to pick up after!

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Whats Next

• Reality check on what the Bacteria TMDLs are
  trying to accomplish
• Reality check on where we should focus our
  efforts
• Human sources
• YES
• Human activities
• Provide the public with knowledge and tools to
  help the environment

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The End