SOURCES OF PATHOGENS COMMON PATHOGENS OF CONCERN Characteristics Escherichia coli(various strains)...

SOURCES OF PATHOGENS

Set Back Distance, 30.5 m (100 ft)

SepticTank

Sewer Line

Sewage-manure Lagoon,

irrigation ditch

Sewage IrrigationSludge Disposal

Water Table

Well ConstructionFailed Well Seal or Cap

Runoff

DistributionSystemPipe Leaks, Biofilms

Surface Water River, Lake

12

4

Time of Travel, 50 d

Landfill

3

Protection Methods

Monitoring

1.

2.

3.

5

COMMON PATHOGENS OF CONCERNCharacteristics

Escherichia coli(various strains)SalmonellaShigellaCampylobacter jejuniYersinia enterocoliticaVibrio choleraeHelicobacterEnterococci

Cryptosporidium

Oocysts4-6 um

PROTOZOA

Giardiacysts8-14 um long7-10 um wide

Trophozoite (feeding stage)9-21 um long 5-15 um wide and 2-4 um thick (Maier et al, 2000)

Coliform genera Escherichia, Klebsiella, Citrobacter and Entrobacter

http://people.ku.edu/~jbrown/ecoli.html

1 to 3 um

Escherichia coli

Fecal Streptococci Enterococcus

1 to 3 um

VIRUSES

Over 140 types of Viruses:

Hepatitis A virus

RotavirusOne of the most common causes of

infantile diarrheaInjection 10 viruses

Enterovirus Groupover 70 membersCoxsackievirus

EchovirusPoliovirus

Norwalk virusNorwalk-like agents

Other VirusAdenovirus

Hepatitis E virusCalicivirus

Astrovirus

Adenovirus70-100 nm

Norwalk27-34 nm

Polio28 nm

100 nm=1 um

FACTORS CONTROLLING PATHOGENIC SURVIVAL, TRANSPORT AND FATE

Fluid Properties

1. pH2. Ionic strength3. Organic mater

4. TemperaturePorous Media Properties

1. Size2. Composition3. Isoelectric point4. MeOx Coatings5. Organic Material

6. Distribution of K, n, v, dispersivities

PHYSICAL SYSTEM

Pathogen Properties

1. Size2. Surface Composition3. Isoelectric point4. Motility5. Reproduction

6. Inactivation

SIZE EXCLUSION AND BIOLOGICAL FACTORSIMPACTING CONCENTRAITONS

(0.02 to 14 um)

Sorption and attachment-detachmentGW

t2

C

Time

Bromide

Lowers Conc.

May retard Peak Conc.

Re-release ofpathogenslow conc. over long periods of time

3.

2.

1.

pathogens

1.

2.3.

PHYSICAL PROCESSES IMPACTING CONCENTRATIONSAdvection Dispersion

Slug Source of Pathogens

t3t2

t1

Map View

t1

t2 t3

C

Distance from the source

Peak concentration

Dilution !

SCIENCE TO SUPPORT POLICY:Additional Research Needs

1. Pathogen survival studies. Protozoa, bacteria and viruses

2. Additional field transport and fate studies in varyinghydrogeological settings applying pathogenic and non pathogenictracers.

3. Development of predictive models for pathogenic transportin multiple groundwater settings.

4. More reliable analytical methods that allow separation of pathogenic and non pathogenic micro-organisms.. New analytical techniques, antibody assays, PCR, etc. (speciation)

Increase sensitivityCost considerations

Controls on the Transport of Pathogens in Groundwater Systems

William W. Woessner Department of Geology, University of Montana, Missoula, MT

william.woessner@umontana.eduMay 12-15, 2004 NAGT Geology and Human Health

TEMPERATURE AND SURVIVAL OF PATHOGENS

IN GROUNDWATER(Die-off or inactivation)BACTERIA

HYDROGEOLOGIC PROPERTIES AND RESIDENCE TIME

TRANSPORT RATES OF SOLUTES, PATHOGENS?? IN GROUNDWATER

Dominate Material Expected velocity Time of Travel 30 m Clay and silt <0.01 to 0.05 m/d 3,000 to 600 d

Sand 0.05 to 1.0 m/d* 600 to 30 d

Sand and Gravel 1.0 to 10 m/d* 30 to 3 d

Gravel 10 to >100 m/d* 3 to < 0.3 d

Rock (fract) 0.3 to 8,000m/d * 100 to 0.004 d

Rock (Karst) up to 26,000 m/d* up to 0.001 d

* ( after Pekdeger and Matthess, 1983)

EXAMPLE:VIRUS FIELD EXPERIMENTS, TRAVEL DISTANCES

(Bales et al. 1995)

(DeBorde et al., 1998)

(DeBorde et al., 1999)

(Rossi et al., 1994)

Sand and Gravel

Sand

(Bales et al. 1997)

Cape Cod, MA

Emme Valley, Switzerland

Cape Cod, MA

Frenchtown, MT

Erskine, MT

Borden, ON

+900m(Noonan and McNabb, 1979) Canterbury Plains, New Zealand

(Peters et al., 1997)

(Ryan et al., 1999;Piper et al, 1997)

Castricum AR System, Netherlands

3 d

3 d

5 d

0.5 d

26 d

6 d

3 d

24 d

Fractured Rock, Karst (Ls)

010 20

30 40 50 60

Transport Distance in meters

0.5 d(McKay et al, 2000))

TN, USA

Sources of Groundwateroutbreaksover 25 y,

USEPA GWRule Draft, 2000

HEALTH ISSUES

AGENT Survival Data

Cryptosporidium oocysts* 540 d 4C*

50

25

50 100days

CGiardia cysts*

8C 77 d

Fecal coliform E. coli

*Canter and Knox, 1985**Yates & Yates, 1987.

Die-Off in log10/day = 0.018(T) - 0.144where a 4 log drop was used.

Virus**

90 to 135 d*

50

25

50 100days

C8C ~no inactivation

#

10C GW 180+ days observedWoessner 2002, unpublished data