Assessing the performance of cold climate natural wetlands in the treatment of domestic wastewater...

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