Wastewater and the Environment

Gippsland Water has a legal requirement to ensure their activities do not cause harm to the environment, one way of achieving this is by monitoring its discharges to the environment. This monitoring is reported to the Environment Protection Authority (EPA) and the community through Gippsland Water's Customer and Environment Committee and annual reports.

Environmental compliance of wastewater treatment plants and wastewater reuse

The following tables provides a breakdown of compliance of all wastewater facilities, as measured against EPA licence requirements and reuse and discharges of treated wastewater, for 2006-07.
 
 
Volume reused (ML)
Volume discharged (ML)
Compliance with EPA Water Quality Limits
Treatment
system
Final fate of treated water
2005-06
2006–07
2005–06
2006–07
2005–06
2006–07
Drouin
Irrigation to pasture or
discharge to Shillinglaw Creek
204
255
186
143
100%
100%
Heyfield
Irrigation to pasture
54
59
0
0
100%
100%
Maffra
Irrigation to pasture and sporting field
203
166
0
0
100%
100%
Mirboo North
Irrigation to pasture and sporting field
31
96
0
0
100%
100%
Morwell
Supplement flow to wetlands
620
556
0
0
98.6%4
1
Stratford
Irrigation to pasture
88
70
0
0
100%
100%
Willow Grove
Irrigation to pasture
10
8
0
0
100%
100%
Neerim South
Discharge to Red Hill Creek
0
0
50
46
88.9%5
1
Rawson
Discharge to CoopersCreek
0
0
33
37
100%
100%
Warragul
Discharge to HazelCreek
0
0
1,436
1,193
100%
100%
Moe
Discharge to MoeRiver
0
0
2,054
1,550
100%
100%
Sub-total
 
1,210
1,210
3,759
2,969
 
 
% reuse1
 
24.4%
29.0%
 
 
 
 
ROS2
Discharge to Bass Strait (Delray Beach)
0
0
8,398
9,498
100%
100%
SWOP2
Discharge to Bass Strait (McGauransBeach)
0
0
7,434
7,957
100%
100%
Total
 
1,210
1,210
19,795
20,424
 
 
% reuse3
 
6.1%
6.1%
 
 5.6%
 
 

1          Percentage of non-saline treated wastewater.

2          Ocean disposal of treated highly saline wastewater, unsuitable for reuse.

3          Percentage of total volume of treated wastewater.

4          Mechanical failure of an aerator caused the discharge of a high concentration of ammonium nitrogen.

5          Problems with biomass health caused a period of poor biological removal of phosphorus.

 

Average composition & volume of wastewater recieved in the Regional Outfall Sewer (ROS) (Inlet No. 2 Storage)

Parameter

Units

Mean

Minimum

Maximum

Flow

ML/month

848.0

717.1

957.3

pH

units

8.3

7.7

8.7

Electrical conductivity

mS/cm

2467

1800

5900

Suspended solids

mg/L

170

2

320

Biochemical oxygen demand

mg/L

112

63

190

Total nitrogen

mg/L

22

5.3

29

Total phosphorus

mg/L

4.9

2.4

6.6

 

Loy Yang Ash Pond at Saline Wastewater Outfall Pipe (SWOP) pump station-continuous monitoring data

Month

Flow (ML/Day)

pH

Turbidity (NTU)

Min

Max

Mean

Volume

Min

Max

Max1

Mean

90th %ile

July 2006

0.2 35.9 34.5 545.6 8.8 9.5 41.8 14.9 21.8

August 2006

0.1 35.8 33.0

539.7

8.9 9.4 49.3 16.1 20.5

September 2006

0.0 35.9 32.4

740.7

8.1 9.7

33.6

20.1 24.4

October 2006

1.0 35.6 30.8 776.6 9.2

9.7

32.2 15.9 21.0

November 2006

0.0 35.2 29.3

505.3

8.2 9.8 32.5 17.4 23.7

December 2006

0.0 35.4 30.3

633.9

8.4 9.6 32.7 16.9 23.6

January 2007

1.0

36.7

31.8

783.0

8.7 9.9 32.9 16.7 22.7

February 2007

0.1

35.1

33.1

718.1

7.7 9.5 33.9 15.1 25.9

March 2007

0.9

34.9

31.0

740.5

7.9 10 30.0 16.2 22.4

April 2007

0.0

35.2

29.7

587.7

7.9 9.6 33.1 16.3 24.0

May 2007

0.0

35.3

31.7

545.0

7.6 9.5 34.5 15.2

21.3

June 2007

0.6

35.2

32.8

817.9

8.9 9.4 32.2 15.1 21.8

Specified licence limits

   

35

 

7.0

10.5

25

   

1Where the value observed maximum exceeds the EPA licence limit, the pumps were subsequently shut off automatically soon after.

Monitoring wastewater discharge

The EPA is charged with the responsibility of monitoring Gippsland Water's wastewater discharges and treatment.  This is to ensure that our environmental resources are preserved.  They have developed a State Environment Protection Policy for Victoria, which provides a legal framework for State and local government agencies, businesses and communities to work together to protect and rehabilitate Victoria's surface water environments.

Gippsland Water has committed significant capital resources in order to meet new requirements.  Regular monitoring is undertaken of all our discharge points to ensure that our environmental licence requirements are adhered to.