prepared by becky jimenez nsf reu civil infrastructure...

Prepared by Becky Jimenez

NSF REU Civil Infrastructure Engineering, UH, Summer 2009

� Background and Theory

� Site Details

� Bacteria

� Lab Processing� Lab Processing

� Analysis

� Conclusion

� Total Coliform and E.coli concentrations higher in

sediment than water

o Decreasing Sunlight Inactivation

o Protection from predationo Protection from predation

o Increased nutrient availability

o Colonizable surface

E. COLI

� Total Coliforms

� Fecal indicator bacteria

(FIB)(FIB)

o E. coli

YSI READINGS UV READINGS

Lab Lab

ProcessingProcessing� Matching samples according to time

�Dilutions (Different for Sediment)

�Adding reagent

�Shaking

�Placed into Quanti-trays and Sealed

24 Hour Incubation at 35 degrees � 24 Hour Incubation at 35 degrees

Celsius

WATER SAMPLES SEDIMENT SAMPLES

Requirements:

• Geometric Mean < 126 MPN/dL

• Individual Samples cannot exceed 394 MPN/dL more than 25% of the time

2000

2500

3000

Co

nce

ntr

ati

on

(M

PN

/dL) Geometric Mean

0

500

1000

1500

2002 2003 2004 2005 2009E.

co

li C

on

cen

tra

tio

n (

MP

N/d

L)

Years

Geometric mean of E. coli concentrations for different years

Cole Creek

Samples

Collected

Samples > 394

MPN/__ % Exceeding Standard

Geometric

Mean

Water

(MPN/dL) 24 15 62.5 441

Sediment

(MPN/kg) 24 24 100 110470

100limit over samplesof number

standardexceeding % ×=

CONCENTRATION IN: TOTAL COLIFORM E. coli

SEDIMENT (MPN/kg)

MINIMUM 238200 7100

MAXIMUM 24196000 1670000

WATER (MPN/dL)

MINIMUM 19177 147

MAXIMUM 61410 2894

Maximum and minimum

E. coli and total coliform

concentrations

100evaluated samplestotal number

limit over samplesof number standardexceeding % ×=

TOTAL COLIFORM

CONCENTRATION IN

WATER CHANGE

WITH TIME

FLUCTUATION OF

TOTAL COLIFORM

CONCENTRATION

IN SEDIMENT

VARIABILITY OF E. COLI

CONCENTRATION IN

WATER

FLUCTUATION OF E. COLI

CONCENTRATION IN

SEDIMENT

y = 1245.3e-2.38x

R² = 0.666

0

200

400

600

800

6:00 AM 9:00 AM 12:00 PM 3:00 PM 6:00 PM

E. c

oli

co

nce

ntr

ati

on

(MP

N/d

L)

Time

Time and E. coli Expon. (Time and E. coli)

Conclusions and Questions

The research study described herein was sponsored by the National

Science Foundation under the Award No. EEC-0649163. The opinions

expressed in this study are those of the authors and do not necessarily

reflect the views of the sponsor.

I would also like to thank Dr. Hanadi Rifai, Anu Desai, Sean Carbonaro,

Norma Moreno, Scott Rauschhuber, Yaa Amoah, Sharon Wells, Nathan Norma Moreno, Scott Rauschhuber, Yaa Amoah, Sharon Wells, Nathan

Howell, Jenni McFarland, Lisa Grecho, Maria Modelska, Stephen Ray,

Zack Van Brunt, Matt Feaga and Divagar Lakshmanan.