Assessing the performance of cold climate natural wetlands in the treatment of

domestic wastewater effluents in northern Canada

Gordon Balch‡, Brent Wootton‡, Colin Yates†, Sven Jørgensen¥ and Annie Chouinard§ ‡Centre for Alternative Wastewater Treatment, Fleming College, Lindsay †Faculty of Environment, University of Waterloo, Waterloo

¥ Water Research Laboratories, ASP, Væløse, Denmark § Civil Engineering Queen’s University, Kingston

Arctic Change Conference: T39-Planning, Design & Assessment of Water Resource Systems in Northern CommunitiesThursday, December 11th, 2014, Ottawa, Ontario

2

Focus• Wetlands are providing a

treatment benefit• Assessment tools are available• Wetlands could be part of a

hybridized wastewater treatment strategy

3

Background• CCME guidelines• Present and future

challenges for lagoon systems

• Tundra wetlands exist downstream of lagoons

Pond Inlet – sewage lagoon

Paulatuk– sewage lagoon

4

Question: do wetlands provide treatment?

• Anecdotal evidence• Answer hampered by– Lack of knowledge – Lack of standardized testing– Inability to predict response

to changing conditionsUlukhaktuk

Wetland Surveysi. Arctic Summer (inlet, outlet)– Seasonal trend–No pretreatment or pretreatment (facultative

lakes or lagoons)– Lagoon decants / exfiltration– Performance (BOD5, TAN, TSS, microbial,

etc.)– Calibration of SubWet 2.0 rate coefficients for

Northern conditions

5

0

50

100

150

200

250

300

350

Influent

Arviat, NunavutB O D 5 m g

-

L

Sampling Dates

0

5

10

15

20

25

30

35

40

45

Influent

Coral Habour, NunavutT

o tal A m m on ia

Ni tr og en

m g -

L

Sampling Dates

8

Wetland Surveysii. Intensive Sampling– Rapid, intensive testing (2-4 days)– Sampling stations along transects

cBOD5 TKN TAN TSS

Influe

nt PI9 PI8 PI7 PI6 PI5 PI4 PI3 PI2 PI10

102030405060708090

100%FSS %VSS

Sample Location

Perc

ent C

ompo

sitio

n

Composition of Total Suspended SolidsPond Inlet

Influent Efflluent0

50

100

150

200

TSS

Influe

nt a

Influe

nt b

T1S2

T7S3

T8S1

T8S4

T10S

1T1

0S2

T10S

4T1

1S1

0102030405060708090

100 %FSS %VSS

Sample Location

Perc

ent C

ompo

sitio

n

Composition of Total Suspended Solids Ulukhaktok

Influent effluent0

50010001500200025003000

TSS

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Predictive tools – SubWet 2.0

• 16 rate coefficients• 25 differential equations• Easily obtained input parameters• Ability to calibrate to site conditions• Models BOD5, Ammonium, Organic Nitrogen,

Nitrate and Total Phosphorus• Easy to use• Available as free-ware

• Calibrated to 11 individual tundra treatment wetlands

Nunavut: Arviat, Coral Harbour, Gjoa Haven, Pond Inlet, Repulse Bay, Whale CoveNTW: Edzo, Fort Providence, Paulatuk, Taloyoak, Ulukhaktuk

% Derivation of Simulation from Measured

Nunavut NTWBOD5 Ammonium Total

PhosphorusBOD5 Ammonium Total

Phosphorus

Arviat 18 7 2 Edzo 8 15 9

Coral Harbour 5 14 8 Fort Providence 79 57 56

Gjoa Haven 2 3 12 Paulatuk 30 10 1

Pond Inlet 5 4 4 Taloyoak 15 2 9

Repusle Bay 5 4 4 Ulukhaktuk 5 16 11

Whale Cove 64 10 34

• Provides the lagoon operator the ability to forecast how the wetland will respond

• Forecast future capacities and needs

13cawt.ca

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Coral Harbour

Northern Wastewater Strategy

Hybridized approach (lagoons + wetlands)

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Concluding Remarks• Wetlands do provide treatment

benefit • Sampling protocols and predictive

tools exist• Consideration of a hybridized

approach should be considered

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Concluding Remarks• Demand for decentralized treatment likely to

increase• Demand for specialized treatment to off-load

burden to centralized systems may increase• May see greater need for advanced treatment

systems for Nitrate and Phosphorous in relationship to source water protection

Acknowledgements