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Reducing EnvironmentalRisk in Agriculture

Pathogen Management:The Atlantic Perspective

Dr. Glenn Stratton, P.Ag.Nova Scotia Agricultural College

Atlantic Committee on Land and EngineeringWorkshop 2001

Environmental Risk in Agriculture:• Risks to the hydrosphere

– Water quality issues

• Risks to the lithosphere– Soil quality issues

• Risks to the atmosphere– Global warming – greenhouse gases

• Risks to the biosphere– Ecological impacts

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The primary pathogen manage-ment issue for reducing environ-mental risk in agriculture ispresently water quality• Walkerton, Ontario – May 2000

– Escherichia coli O157• North Battleford, Saskatchewan – May 2001

– Cryptosporidium• Boil water orders in Atlantic Canada

Water quality and agriculture

• Microbiological quality of surface waters– Source of drinking water for 74% of the

population in Canada

• Microbiological quality of ground water– Source of drinking water for 26% of the

population in Canada– Higher levels in Atlantic Canada

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Groundwater demand

Pathogens of particular concern

• Coliforms – have natural sources• Fecal coliforms - coliforms in feces• Escherichia coli - main fecal coliform• Parasites – from fecal sources

– Cryptosporidium– Giardia

• Other bacteria – pathogens– Salmonella, Shigella, Campylobacter, etc.

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Surface water quality: Concerns

• Non-point sources of pollution– Run-off from fields treated with manure or

sewage sludge/septage

• Point sources of pollution– Drainage discharge from fields treated with

manure or sewage sludge/septage– Overflow from manure storage facilities– Run-off from solid waste storage

Manure application – field study

Collection of surface runoff usingHickenbottom Surface Inlets

- installed at the end of ditches-one ditch for each surface plot-surface inlets connected to sub-surface drain lines that run to acollection building

Non-Point Source of Pollution

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Surface runoff – beef manure

J u lia n D a te

1 4 5 1 5 0 1 5 5 1 6 0 1 6 50

2 0

4 0

6 0

1

1 0

1 0 0

1 0 0 0

D ra in D is c h a rg eF e c a l C o lifo rm s

Flow event at Streets Ridge - Beef manure applied May 20/00D

rain

Dis

char

ge L

/h

Fec

al c

olif

orm

s / 1

00 m

L

May 23/00 Jun.14/00

Watershed Study – Microbial Loads

Non-Point Source of Pollution

Cornwallis River watershed: Thomas Brook sub-watershed; ~900 ha – agricultural region – fecalcoliforms a known problem

* Sampling locations

To the CornwallisRiver

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Thomas Brook Watershed study

Thomas Brook Watershed study

01020

304050607080

90100

Site 1 Site 2 Site 3 Site 4 Site 5

% of samplesexceeding the guide-lines forfecal coliformsin recrea-tionalwater

Samples collected 20 times from May 09/01 to Sept. 26/01

Nearest Cornwallis River

Head Waters

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Manure application: tile drain leachate

Point Source of Pollution

Tile drains – hog manure applied to field

Julian Date

330 332 334 336 338 340 342 344 346

Dra

in D

isc

ha

rge

L h

-1

0

10

20

30

40

Fe

ca

l C

oli

form

s 1

00

mL

-1

1

10

100

1000

Drain DischargeFecal Coliform s

Flow event at Truro - Hog manure applied May 19/00

Nov.25/00 Dec.10/00

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Tile drains – dairy manure application

Julian D ate

4 6 8 10 12 14 16

Dra

in D

isc

ha

rge

L h

-1

0

100

200

300

400

500

Fe

ca

l C

oli

form

s 1

00

mL

-1

1

10

100

1000

Drain D ischargeFecal Coliform s

Flow event at Onslow - Dairy manure applied Jun.04/99

Jan.03/00 Jan.15/00

Surface water quality: Concerns

• Drought conditions in Atlantic Canada– Irrigation with water containing pathogens

from both point source and non-pointsource pollution

– Farm ponds for livestock watering –contaminated with pathogens

– Increased access to surface water forlivestock watering – point source pollution

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Irrigation – chlorination study

0

100

200

300

400

500

RiverWater

IrrigationWater

RiverWater

IrrigationWater

RiverWater

IrrigationWater

Non-chlorinatedpumping station

Chlorinatedpumping station

Fecal Strept

Fecal Coliforms

Escherichia coli

Cornwallis River, NS – Irrigation source for strawberry fields

Groundwater quality: Concerns

• Leachate from fields treated withmanure or sewage sludge/septage

• Leachate from solid waste treatmentfacilities

Non-Point Source of Pollution

Point Source of Pollution

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Fecal coliforms & manure – soil columns

Cummulative Fecal Coliforms

1

10

100

1000

10000

1 2 3 4 5 6

Time (Days)

Fec

al C

olif

orm

s (

MP

N)

Control

Beef

Swine

Poultry

Columns containing packed soil – several manure types applied

E. coli from manure – Soil Columns

Intact soil cores - collection Intact soil cores – lab set-up

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E. coli from manure – Soil Columns

0

200

400

600

800

1000

1200

1 2 3 4 5 6 7 8 10 12 14 16

Weeks of Simulated Rainfall

# E

. col

i / 1

00 m

l

untilled tilled

E. coli in leachate from intact soil cores

E. coli from manure – Survival in soil

Field plots – manure application – with and without tillage

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E. coli from manure – Survival in soil

0

10000

20000

30000

40000

50000

60000

1 2 3 4 5

Weeks after addition of manure

# E. coli per g

tilled untilled

E. coli in field plots treated with manure

Solid waste treatment: Composting

• Manure – benefits of composting– Nutrient stabilization– Pathogen reduction

• Animal mortalities – disposal options– Rendering plants– Burial on-site– Composting – mink, hogs

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Composting structure at BEEC

Leachate: Mink Manure BOD5

0

50

100

150

200

250

Jun.

07/0

0

Jun.

09/0

0

Jun.

23/0

0

Jul.0

5/00

Nov

.24/

00

Nov

.29/

00

Dec

.18/

00

Dec

.20/

00

Manure (open)Manure (cover)

BOD(mg/L)

-----Trial #1----- -----Trial #2-----

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Leachate: Mink Carcass BOD5

020406080

100120140160180

Jun.

07/0

0

Jun.

09/0

0

Jun.

23/0

0

Jul.0

5/00

Nov

.24/

00

Nov

.29/

00

Dec

.18/

00

Dec

.20/

00

Mink (open)Mink (cover)

BOD(mg/L)

-----Trial #1----- -----Trial #2-----

Hog Mortality project at BEEC

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Leachate: Hog Carcass - fecal coliforms

0

5

10

15

20

Feca

l Colif

orm

s M

PN

/100m

L

07/04 07/05 07/06 07/12 07/13 07/18 07/23Time

Sawdust Manure Manure and tarp

Fecal ColiformsSubsurface Drainage

Wastewater treatment: Wetlands

• Non-point source pollution: Naturalwetlands

• Point source pollution: Constructedwetlands– Milk house wash waters– Manure storage lagoon overflow– Manure storage pad runoff

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Constructed farm wetland at Eureka

Constructed research wetland at BEEC

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Treatment efficacy for fecal coliforms

Fecal coliforms

MonthNov. Dec Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sept.

(MP

N/1

00m

L)

0.0

5.0e+8

1.0e+9

1.5e+9

2.0e+9

2.5e+9

3.0e+9

3.5e+9

Inflow Outflow

• Improved management of agriculturalwastes (resources) …– to reduce the risk of introducing pathogens

into surface and groundwater– to reduce the risk of introducing pathogens

into soil – another route to water– to reduce the risk of introducing pathogens

onto crops

Reducing EnvironmentalRisk in Agriculture:

Pathogen Management

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Contributors of materials presented

• Dr. Rob Gordon, NSAC• Dr. Ali Madani, NSAC• Dr. Peter Havard, NSAC• Laura MacDonald, M.Sc. Candidate, NSAC• Erin Smith, M.Sc. Candidate, NSAC• Krista Sharples, M.Sc. Candidate, NSAC• Tricia Coulter, M.Sc. Candidate, NSAC• Paula MacDonald, M.Sc. Candidate, NSAC• Terra Jamieson, M.Sc. Graduate, NSAC• Jennifer Ferguson, M.Sc. Graduate, NSAC• Autumn Biggar, B.Sc.(Agr.) Graduate, NSAC