Mobile Laboratories: An Innovative Approach in

Bacteria Monitoring

Mindy K. GarrisonOhio River Valley Water Sanitation Commission

Arthur GarceauIndiana Department of

Environmental Management

Why a Mobile Lab?Monitoring over large areasSix - hour hold timeAnalysis done on siteNumerous samplesThe method is simple enough to perform numerous samples in a very small spaceMobility provides easy access to the laboratory for various types of sampling crews

IDEM’sIDEM’s Mobile Mobile

E. coli E. coli LaboratoryLaboratory

Advantages of Mobile Laboratory:

Eliminates the necessity of transporting samples to lab within a 6-hour holding time

Can collect, prepare, incubate, read, and dispose of up to 40 samples per day

Complete analysis in field to increase the number of tests performed

ORSANCO Mobile Lab

Analytical Method

IDEXX Colilert ® Quanti-Tray 2000Standard Methods 20th Edition 9223 B

US EPA has accepted this method for use in drinking water programs and ambient water

E.coli Method ComparisonColilert® Method vs. Membrane Filtration• IDEXX Colilert® Method

• Standard Methods MPN Approach• Presence/Absence or Quantification

• Test Methods•Colilert®

total coliforms & E. coli

Colilert® Benefits

• Test Procedure•1 minute hands-on time•no media preparation

• Interpretation of Results• colony counting eliminated• no subjectivity (atypical, overlapping)• no confluent growth

• Cost• reduced labor

Figure 3: IDEXX Colilert® Method for E. coli Analysis

Reprinted with the permission of IDEXX Laboratories

Sealing Quanti-trays

Counting Coliforms

Counting E.coli

Samples in Incubator

IDEM Budget

2000 Chevy Van w/Conversion = $28,000Lab Equipment = $10,000Supplies = $7,000Grand Total = ~ $45,000

IDEM’s E.coli MonitoringProgram Description

Statewide Study AreaSurface water: Rivers, streams and lakes

Sites selected are known recreational and public access areasEach location is sampled five times equally spaced over a 30-day period

Single samples

956469 583 566

921

548 332 228

806

438 130 220

0

500

1000

1500

2000

2500

3000

West Fork White RiverWatershed 2001

Upper Wabash Watershed2003

East Fork White River 2002 Great Lakes Watersheds2000

Watersheds

# of

sam

ples

take

n

Samples Greater than 940/100mL

Samples from 235 to 940 /100mL

Samples Less than 235/100mL

Single samples

956469 583 566

921

548 332 228

806

438 130 220

0

500

1000

1500

2000

2500

3000

West Fork White RiverWatershed 2001

Upper WabashWatershed 2003

East Fork White River2002

Great LakesWatersheds 2000

Watersheds

# of

sam

ples

take

n

Samples Greater than 940/100mL

Samples from 235 to 940 /100mL

Samples Less than 235/100mL

Single E. coli Sample Results for Indiana Watersheds 2000-2003

32% 36%44% 50% 56% 56%

63% 66%74%

38% 34%33%

38% 32%22%

31% 22%17%30% 30% 23%

12% 12%22%

12% 9%6%

0%10%20%30%40%50%60%70%80%90%

100%

Upper

Wabash

Wate

rshed

2003

West Fo

rk Whit

e Rive

r Wate

rshed

2001

Kank

akee

& Ill

inois F

ixed S

tation

s

Great M

iami W

atersh

ed 20

02

East

Fork

White R

iver 2

002

Great L

akes W

atersh

eds 2

000

Lower

Wabash

Wate

rshed

Fixe

d Stat

ionsS

Ohio Trib

s 200

0

Patok

a Wate

rshed

2001

Samples Greater than 940/100mL

Samples from 235 to 940 /100mL

Samples Less than 235/100mL

ORSANCO’sSampling Plan

Sampling the entire Ohio River (981 miles) in three surveys3 point cross sections

Every 5 milesOn all major tribs (> 1000 sq. miles)Downstream of all POTWs > 0.5 MGD

Cover entire reach in 1 weekSample 5 consecutive weeks

ORSANCO’s Budget

Mobile Lab – Ford E-450 Cutaway Van Cab with 17’ box = $94,000Equipment = $15,000Supplies for 4600 samples w/ two dilutions per sample = $55,000Grand Total =~ $164,000

ORSANCO’sSampling Plan

Two surveys have been completed:Pittsburgh to R.C. Byrd L&D (280 river miles)R.C. Byrd L&D to Salt River (350 river miles)

Third survey began May 3rd 2004Salt River to Mississippi River

Allegheny

Monongahela

Beaver

Muskingum

Scioto

HockingL. Miami

G. Miami

Wabash

Embarass

L. Wabash

L. Kanawha

Kanawha

New

Big SandyLicking

KentuckySalt

Green

Cumberland

Clinch

Holston

French BroadL. Tennessee

Hiwassee

Tennessee

Duck

Tennessee

Ohio

SalineOhio

OhioILIN OH

PA

NY

VA

WV

MD

KY

TNNC

GAAL

MS

Ohio River Basin

W. Fork White

E. Fork White

Elk

Guyandotte

Youghheny

ORSANCOSurvey Stats

825 cross sections completed2950 samples collected

Includes duplicates

5800 samples analyzedIncludes dilutions + quality controls

Contract lab samples analyzed for E. coli and fecal coliform (~ 20%)

Upper River Bacteria SurveyCross-Sectional Mean

July 28 - Aug 28, 2003

0

500

1000

1500

2000

2500

0 70 140 210 280

Ohio River Mile

E. c

oli (

CFU

/100

mL)

Wk 1Wk 2Wk3Wk 4Wk 5WQSWater Quality Standard

Middle River Bacteria SurveyCross-Sectional Mean

Sept 29 - Oct 30, 2003

0

500

1000

1500

2000

2500

280 330 380 430 480 530 580 630

Ohio River Mile

E. c

oli

(CFU

/100

mL)

Wk 1Wk 2Wk3Wk 4Wk 5WQSWater Quality Standard

Contract Lab Duplicate AnalysisE. coli by Membrane Filtration

R2 = 0.8257

0

400

800

1200

1600

2000

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Sample (CFU/100 ml)

Dup

licat

e (C

FU/1

00 m

l)

Average Relative % Difference: 32.1%

Mobile Lab Duplicate AnalysisE. coli by Colilert

R2 = 0.980

0

200

400

600

800

1000

1200

1400

1600

0 200 400 600 800 1000 1200 1400 1600

Sample (MPN CFU/100ml)

Dup

licat

e (M

PN C

FU/1

00m

l)

Average Relative % Difference: 26.2%

Colilert vs Membrane FiltrationE. coli Comparison by Lab

R2 = 0.8533

R2 = 0.5818

R2 = 0.9405

0

500

1000

1500

2000

2500

3000

3500

4000

0 500 1000 1500 2000 2500 3000 3500 4000

Colilert MPN (CFU/100 ml)

MF

(CFU

/100

ml)

Cardinal MicroBac MicroBio

Membrane Filtration vs. ColilertComparison to E. coli Standard

MF Exceed MF No Exceed

9119.4%

255.3%

132.8%

34072.5%

Colilert Exceed

Colilert No Exceed