Using water quality and infauna data to understand the

environmental impacts of wastewater discharge

Peter Crockett and Scott Chidgey

A tale of two outfalls

Altona STPMurray Goulburn Co-op

2004/2005

2005/2006

2006/2007

2007/2008

2008/2009

2009/2010

2010/2011

2011/2012

2012/2013

2013/2014

0

50

100

150

200

250

300

350

Total nitrogen loads

Altona STP

Murray Goulburn LeongathaTonnes

Distance (≈ Exposure-1 )

Response

Dose-Response

Water Quality

Infauna

Altona Outfall

Total phosphorus concentrations as

proportion of background median

Median background

2.5 X background

5 X background

10 X background

20 X background

>20 X background

307500 307550 307600 307650 307700 307750 307800 307850

Easting (metres)

5804700

5804750

5804800

5804850

5804900

5804950

5805000

5805050

No

rth

ing

(m

etre

s)

0

100

250

500

1000

2000

307500 307550 307600 307650 307700 307750 307800 307850

Easting (m etres)

5804700

5804750

5804800

5804850

5804900

5804950

5805000

5805050

No

rth

ing

(m

etre

s)

0

100

250

500

1000

2000

307500 307550 307600 307650 307700 307750 307800 307850

Easting (metres)

5804700

5804750

5804800

5804850

5804900

5804950

5805000

5805050

No

rth

ing

(m

etre

s)

307500 307550 307600 307650 307700 307750 307800 307850

Easting (m etres)

5804700

5804750

5804800

5804850

5804900

5804950

5805000

5805050

No

rth

ing

(m

etre

s)

June 2006Background median TP: 0.14 mg/L

April 2008Background median TP: 0.09 mg/L

March 2010Background median TP: 0.10 mg/L

March 2011Background median TP: 0.18 mg/L

Altona OutfallAbundance by infauna family, 2004-2015

≤ 50 m % ≥ 100 m %

Capitellidae 24 Galeommatidae 19 Galeommatidae 15 Capitellidae 12 Phoxocephalidae 9 Phoxocephalidae 10 Magelonidae 7 Magelonidae 10 Opheliidae 6 Opheliidae 7 Gynodiastylidae 4 Gynodiastylidae 6 Orbiniidae 3 Orbiniidae 4 Nematoda 3 Veneridae 4 Corophiidae 2 Cirolanidae 3 Veneridae 2 Spionidae 2

Capitellidae

Galeommatidae

Altona OutfallInfauna abundance, 2004-2015

250 100 50 25 5 5 25 50 100 250South North

0

5000

10000

15000

20000

25000

30000

35000

40000MedianReference 80th percentileReference 20th percentile

Distance from outfall (m)

Infa

una

per s

quar

e m

etre

Altona OutfallAbundance of Capitellidae, 2004-2015

Jan-

04

Nov

-05

Apr-

06

Nov

-07

Jan-

08

Dec

-08

Mar

-10

Apr-

11

Oct

-11

Jul-1

2

Feb-

13

Apr-

13

Jun-

13

Mar

-14

Mar

-15

0

500

1000

1500

2000

2500

3000

3500

4000

≤ 50 m ≥ 100 m

Aver

age

num

ber p

er sq

uare

met

re

399850 399900 399950 400000 400050 400100

Easting

October 2010 - background median total phosphorus: 0.010 mg/L

5709000

5709050

5709100

5709150

5709200

5709250

No

rth

ing

-1

1

2

5

10

20

October 2010Background median TP: 0.010 mg/L

399850 399900 399950 400000 400050 400100

Easting

August 2012 - background median total phosphorus: 0.017 mg/L

5709000

5709050

5709100

5709150

5709200

5709250

No

rth

ing

-1

1

2

5

10

20

August 2012Background median TP: 0.017 mg/L

399850 399900 399950 400000 400050 400100

Easting

December 2013 - background median total phosphorus: 0.010 mg/L

5709000

5709050

5709100

5709150

5709200

5709250

No

rth

ing

-1

1

2

5

10

20

December 2013Background median TP: 0.010 mg/L

399850 399900 399950 400000 400050 400100

Easting

March 2015 - background median total phosphorus: 0.012 mg/L

5709000

5709050

5709100

5709150

5709200

5709250

No

rth

ing

-1

1

2

5

10

March 2015Background median TP: 0.012 mg/L

Venus Bay Outfall

Total phosphorus concentrations as

proportion of background median

2 X background

5 X background

10 X background

Median background

1.5 X background

>10 X background

Venus Bay OutfallAbundance by infauna family, 2004-2015

Trochidae (Bankivia sp.)

Cirolanidae

Baseline surveys % Operational surveys % Trochidae 60 Magelonidae 28 Corophiidae 26 Cirratulidae 12 Magelonidae 3 Terebellidae 8 Cirolanidae 2 Lumbrineridae 7 Terebellidae 1 Urohaustoriidae 5 Urohaustoriidae 1 Trochidae 4 Harpactocoid 1 Sigalionidae 4 Ophiuroidea 1 Ophiuroidea 3 Sigalionidae 0 Spionidae 3 Lumbrineridae 0 Sipuncula 3

Venus Bay OutfallInfauna abundance, 2004-2015

Feb-

04

May

-05

Mar

-06

Sep-

08

Apr-

09

Jun-

10

Nov

-10

May

-11

Aug-

12

May

-13

Dec

-13

Mar

-15

100

1000

10000

≥100 m

0-50 m

Aver

age

infa

una

per s

quar

e m

etre

Venus Bay OutfallInfauna abundance, 2004-2015

Feb-

04

May

-05

Mar

-06

Sep-

08

Apr-

09

Jun-

10

Nov

-10

May

-11

Aug-

12

May

-13

Dec

-13

Mar

-15

100

1000

10000

≥100 m

0-50 m

Aver

age

infa

una

per s

quar

e m

etre

Outfallcommissioned

Venus Bay OutfallInfauna abundance, 2010-2015

200 m 100 m 50 m Outfall 50 m 100 m 200 m Mixing Zone Mixing Zone Reference

North South

0

100

200

300

400

500

600

Median operational 80 percentile (reference)20 percentile (reference)

Infa

una

per s

quar

e m

etre

Venus Bay OutfallOphiuroid abundance, 2010-2015

200 m 100 m 50 m 50 m 100 m 200 m Mixing Zone Mixing Zone

North Outfall South

0

5

10

15

20

25

30

35

40

45Median operational 20 percentile (reference)80 percentile (reference)

Oph

iuro

ids p

er sq

uare

met

re

Thanks to

City West Water

South Gippsland Water

Murray Goulburn Co-operative

Infauna Data (Lynda Avery)