Sydney Water Aquatic

Ecosystem Monitoring

Macroinvertebrate MonitoringMeasuring the

impacts of sewage treatment plant discharges

Active Blue Mountains STPs July 1980 (11 active)

Active Blue Mountains STPs March 2002 (4 active)

Wentworth Falls STP Located on the edge of the Blue Mountains World Heritage Area

0

500

1,000

1,500

2,000

2,500

3,000

3,500

91 92 93 94 95 96 97 98 99 00

E153 DS E161 US

S TP decom m issioned

* As at 17/ 09 each year

µg

/L

Figure: Phosphorus upstream and downstream of South Katoomba sewage treatment plant

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

91 92 93 94 95 96 97 98 99 00

E153 DS E161 US

S TP decom m issioned

* As at 17/ 09 each year

mg

/L

Figure: Nitrogen upstream and downstream of South Katoomba sewage treatment plant

2

3

4

5

6

7

8

Upstream Downstream Downstream com parison stream

Probable severeorganic pollution

Probable m oderate

organic pollution

Possible m ildorganic pollution

Clean water

S TPdecom m issioned

Bio

tic i

nd

ex

(S

IGN

AL

-G)

Ecosystem Recovery Following Closure of Wentworth Falls STP

3

4

5

6

7

8

Spring1995

Autumn1996

Spring1996

Autumn1997

Spring1997

Autumn1998

Spring1998

Autumn1999

Spring1999

Autumn2000

Biot

ic in

dex

(SIG

NAL-

G in

terim

)

Upstream Downstream

Clean water

Possible mildorganic pollution

Probable moderateorganic pollution

Probable severeorganic pollution

Wentworth Falls sewage treatmentplant decommissioned

Dragonfly Nymph

Beetle

Stonefly

Midge

Caddisfly

Alien Species

Catchment Development

Impact of Urban Development Rouse Hill Area

2

3

4

5

6

7

8

Sprin

g 19

95

Autu

mn

1996

Sprin

g 19

96

Autu

mn

1997

Sprin

g 19

97

Autu

mn

1998

Sprin

g 19

98

Autu

mn

1999

Sprin

g 19

99

Autu

mn

2000

Sprin

g 20

00

Autu

mn

2001

Period

Biot

ic In

dex

(SIG

NAL-

G)

Upstream Downstream

Clean water

Possible mildorganic pollution

Probable moderateorganic pollution

Probable severeorganic pollution

Sampling of this plantwas delayed due to heavy rain - 260mm fell in October 1999.

Chlorine residualreduction commenced

August rainfall300mm plus after

relatively long dry period

Catchment Development

Photography Credits

The photographs used in this presentation are reproduced with kind permission of the copyright owners: Ian Wright and Sydney Water Corporation.