Microbial Source Tracking Techniques:Lake Michigan Beaches Case Studies

Erika Jensen, M.S. Great Lakes WATER Institute

April 14, 2005

Potential Sources of E. coli • CSOs, SSOs, and septic systems

• Urban and agricultural runoff

• Waterfowl, domestic pets, and wildlife

• Sand, algae, and interstitial waters

240,000 CFU/100 ml 368,000,000 CFU/g feces

250,000-500,000 CFU/100 ml

10,000-100,000 CFU/100 ml

Beach closure 235 CFU/100ml

GLWI Research Areas

Fate and transport of bacteriaMilwaukee Harbor, stormwater, Lake Michigan

Sources of pollution Milwaukee Harbor, stormwater, Lake MichiganDoor, Manitowoc, Milwaukee, & Racine County Beaches

Pathogen occurrence Bradford Beach, Racine, Milwaukee Harbor

Evaluation of BMPsSouth Shore beach, green roofs and rain gardens

Approach to Microbial Source Tracking

1. Gather the experts and share knowledge

2. In depth spatial surveys

3. Targeted sampling to observe dynamics; modeling

4. Apply source tracking approaches: • Human vs. non-human?• Are specific groups of animals contributing?• Does sand or Cladophora act as a reservoir?

5. Manage and evaluate the problem

• 900 sq mi watershed

• 410 miles of streams

• 1.3 million people

• Urban, industrial,

agricultural land uses

Milwaukee River Basin

Bacterial SurveysSpatial & Temporal

South Shore Beach Study: 2001 to present

Menomonee River Study: 2002

Fate and Transport Study: 2002 to present

Manitowoc & Door County Beach Surveys: 2002 - 2003

Bradford Beach Study: 2004 to present

South Shore Beach

Spatial surveys 2001-2004

CSO - 36 hrs, SE wind

Rain, N wind No rain – SE Wind

CSO - 45 hrs, SE wind

2001

riversrivers

Dry weather (baseflow) Wet weather (stormflow)

South Shore Beach

South Shore Beach

E. Coli Level Comparisons: Current & Proposed Beach Sites

Menomonee River Study 2002

Determine river E. coli levels during baseflow and stormflow

Determine E. coli levels of inline stormwater entering river

Characterize “genetic profile” of E. coli in stormwater

Menomonee River Survey

Suburban, suburban industrialNatural bed

Urban, Concrete bed

Urban,Rehabilitated bed

Urban, industrialNatural bed

1 2 3 4 5 6 7 8 9 10

E. Coli Data Menomonee River Survey

Fate & Transport 2003 Spatial Survey

Fate & Transport

CSO EventMay, 14 2004

Hydrodynamic Hydrodynamic ModelModel

• HydrodynamicsHydrodynamics- Transport- Transport- Mixing- Mixing- Dilution- Dilution

• Bacterial counts Bacterial counts

• Die-off is a 2nd order function

• Die off in Lake Michigan is 90% in 6-8 hours

Bacterial Die off in Lake Michigan

Bradford Beach in Milwaukee

Pre-rain 6-14-04 09:44 Post-rain 6-14-04 10:20

E. coli Survival & Persistence in the Environment

E. Coli in Sand

Range

8-39,000 E. coli/100 g

E. Coli Levels at Bradford Beach

Pearson correlation (Opt:1.00%) [0.0%-100.0%]

Rep-PCR

100

80

60

40

Rep-PCR

1

2

3

Clonal Populations Suggest Growth

E. Coli from Beach Sand

Bacteroides spp.

Case Studies

• Stormwater

• Beach water

• Agricultural Runoff

• Combined Sewer Overflows

Description E. coliCFU/100ml

Bacteroides spp.

% Pos.

Human

% Pos.Cow

% Pos.

Beach Water – Forested Area

300-680 100 17 0

Beach Water – Resort Area

42-190 100 0 0

Beach Water –Agricultural land

1260-2500 100 0 50

Urban Beach –No outfalls

450-600 100 0 0

Urban Beach –with Outfalls

460-15,900 100 89 0

Parking Lot Runoff 300-50,000 100 0 0

• Spatial surveys provide the most useful data Identify hot spots or areas of concern

• Implement targeted sampling surveys to observe site specific dynamics

• Apply source tracking approaches: Human vs. non-human?Are specific hosts contributing?Are there environmental reservoirs?

• Manage and evaluate the problem

Summary

ResearchersAnnette DanielsAlissa SalmoreCaitlin ScopelMichelle LuebkePat BowerOla Olapade

StudentsMagnolia TulodJosh HarrisElissa LewisEmerson LeeJennifer LeeAndrew HollandBecky KirbyHilary StreetBen WestonMorgan DepasMeredith Van Dyke

Graduate StudentsMarcia SilvaSachie OwagaHeidi PirkovLiang PengSukpreet Kaur

Great Lakes WATER InstituteP.I., Dr. Sandra McLellan

Funding kindly provided byMilwaukee Metropolitan Sewage DistrictWisconsin DNRNational Institute of HealthNOAA Sea GrantSC JohnsonWisconsin Coastal Management Program