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Eastern Treatment Plant inputs and discharges

Raw sewage monitoring

The quality of raw sewage entering the plant is described in the following table.
(All data in mg/L unless otherwise indicated).

Parameter, Units
Median1
90th Percentile
Maximum
BOD5 (mg/L) 470 609 790
Suspended Solids (mg/L) 455 788 1600
pH (pH units) 7.2 7.8 8.3
Ammonia as N (mg/L) 42 46 47
Total Combined Nitrogen (mg/L) 69 88 95
Total Phosphorus (mg/L) 16 21 23
Anionic Surfactants MBAS (mg/L) 5 7 8
Cadmium (mg/L) 0.0006 0.0013 0.0024
Chromium (mg/L) 0.026 0.040 0.072
Copper (mg/L) 0.14 0.21 0.66
Lead (mg/L) 0.009 0.017 0.026
Mercury (mg/L)2 0.00012 0.00042 0.00082
Phenol (µg/L) 14.52 65.32 3272
Toluene (µg/L) 2.02 4.92 422
Benzene (µg/L) 0.52 0.52 0.52
PAH's total (µg/L) 42,3 42,3 42,3

Notes:

  1. Some raw sewage parameters for 2006/07 are lower than 2005/06 as the draining of primary sludge (during some part of the year) was stopped for 24 hours before the compliance sampling. This is done as part of the operational control measures to prevent excessive sludge accumulation in these tanks.
  2. 1/2 Limit of Detection Values used. All results found to be less than the detection limits were taken as half the given value i.e. <2 = 1.
  3. Total PAH's are calculated using the sum of the following PAH's:
    (acenapthylene, anthracene, 1,2-benzanthracene, 3,4-benzofluoranthene, benzo (k) fluoranthene, 1,12-benzoperylene, benzo(a) pyrene, chrysene, dibenzo(a.h)anthracene, fluorene and indeno(1.2.3-cd)pyrene. All results were less than the detection limit and were calculated at half the given value i.e. <2 = 1).

Discharge to water

The following results represent samples taken from the final effluent sample point at Trueman's Rd and flow measurements at the Eastern Treatment Plant from 1 July 2006 to 30 June 2007. (All data in mg/L unless otherwise indicated)

Parameter (units)
Median
90th Percentile
Maximum
Licence Limit
Result
Licence Limit
Result
Licence Limit
Result
BOD5 (mg/L) NS 22 NS 36 NS 45
CBOD5 (mg/L) 20 4 40 7 NS 12
Suspended Solids (mg/L) 30 13 60 23 NS 65
pH (pH units) NS 8 NS 8 6 - 9 8.2
Ammonia as N (mg/L) 30 12 NS 21 40 26
Total Nitrogen (mg/L) NS 25 NS 31 NS 36
Total Phosphorus (mg/L) NS 8.2 15 10 NS 11
Anionic Surfactants (mg/L) 0.4 0.2 0.7 0.3 NS 0.40
Cadmium (mg/L)1 NS 0.0001 0.005 0.0001 0.01 0.0009
Chromium (mg/L) NS 0.003 0.075 0.01 0.15 0.014
Copper (mg/L) NS 0.014 0.05 0.023 0.1 0.039
Lead (mg/L)1 NS 0.001 0.05 0.0035 0.1 0.013
Mercury (mg/L)1 NS 0.00005 0.0005 0.00005 0.001 0.00005
Phenol (µg/L) NS 0.5 NS 1.5 100 1.5
Toluene (µg/L) NS 0.5 NS 1.85 50 4
Benzene (µg/L) NS 0.5 NS 0.5 25 0.5
PAH's total (µg/L)2 NS 4 NS 4 15 4
ETP discharge (ML/day)3 NS 295 NS 405 NS 478
Outfall discharge (ML/day)4 540 288 NS 404 NS 478
Total Residual Chlorine (mg/L) NS 0.11 NS 0.22 1.0 0.31
E.coli (orgs/100mL) 200 26 1000 110 NS 610
Enterococci (orgs/100ml) NS 10 NS 69 NS 490
Dissolved Oxygen (mg/L) NS 6.8 NS 7.7 = 6.0 6.0 -9.1

Notes:

  1. All results found to be less than the detection limit were taken as half the limit of detection (LOD) e.g. <8 = 4.
  2. Total Poly Aromatic Hydrocarbons (PAH's) are calculated using the sum of the following PAH's: (acenapthylene, anthracene, 1,2-benzanthracene, 3,4-benzofluoranthene, benzo(k)fluoranthene, 1,12-benzoperylene, benzo(a)pyrene, chrysene, dibenzo(a.h)anthracene, fluorene and indeno(1.2.3-cd)pyrene. Note that laboratory error meant that one of the treated effluent PAH analytical results reported here was from a sample taken on 27th July 2006 rather than on a sample taken before 30th June 2006.
  3. ETP outflow flow excluding South East Water treatment plants that also discharge treated effluent into the South East Outfall.
  4. Calculated Total Outfall flow is the actual flow to the Outfall including South East Water discharges to the South East Outfall minus recycled water taken from the South East Outfall.

NS = No specified limit

Discharge to land

While there was no effluent discharged to land at the Eastern Treatment Plant (for irrigation purposes) the following table shows the results of a recycled water-monitoring program was undertaken during the year. The table reports water quality against the "Class C" requirements specified in the EPA Victoria Publication 464.2 "Guidelines for Use of Reclaimed Water", 2003.

  E. coli median org/100mL BOD5 mg/L
Median 		CBOD5 mg/L
Median 		Suspended Solids
mg/L
Median 		pH
Median
(Range)
Class C Limits < 1000 NA < 20 < 30 6.5 - 9.0
Rising main leaving the Eastern Treatment Plant 1 20 34.5 5 12 7.0 - 8.3
Ballarto Rd Sample Point 7 11 4 12 7.0 - 8.6
Range Rd Sample Point 4 12 4 10 7.0 - 8.3
Trumans Rd Gunnamatta 26 22 4 13 7.0 - 8.1
  1. Eastern Treatment Plant Reuse sample point

 

Effluent flow to the outfall

Daily and monthly median and maximum flows (ML/day) were measured during 2006/07. Monthly median and maximums are shown below. The total outfall flows for 2006/07 are as follows:

Description
Flow (ML)
Comment
ETP Outflow
110,452
 Total outfall pump station flow minus internal plant use
Calculated outfall flow
108,128
Boags Rocks Outfall flow (ETP plus South East Water treatment plant flows, less water recycling)

 

Month
Median (ML/d)
Maximum (ML/d)
July 2006
327
414
August 2006
358
450
September 2006
356
457
October 2006
298
460
November 2006
308
446
December 2006
276
440
January 2007
264
367
February 2007
259
442
March 2007
261
462
April 2007
267
342
May 2007
268
433
June 2007
307
478

 

Bacteriological monitoring - beach samples

Samples of receiving waters were taken throughout the year at six locations along the Gunnamatta and St Andrews beaches as detailed below:

Beach 1 The first bluff east of the discharge point
Beach 2 Gunnamatta West beach opposite the amenities block
Beach 3 Gunnamatta West beach opposite the Surf Life Saving Club
Beach 4 Gunnamatta East beach approximately 350 metres east of sample point two
Beach 5 Le Lievres beach 110 metres west of the discharge point
Beach 6 Rye back beach - main swimming area.

The results are presented as a rolling 30-day median and rolling 60-day 75th percentile as per the recreational water quality guidelines given in the State Environment Protection Policy Waters of Victoria. The day results for E.coli and Enterococci for all samples taken at all the above sample points were consistent with the Policy requirements throughout the year. The results are as follows:

Beach E. coli data (orgs / 100 mL)
State Environmental Protection Policy Waters of Victoria require for primary contact recreation a rolling 30 day median of = 150 Orgs/100 mL.

 
BEACH 1
BEACH 2
BEACH 3
BEACH 4
BEACH 5
BEACH 6
SAMPLE DATE
Day result
30 d Median
Day Result
30 d Median
Day Result
30 d Median
Day Result
30 d Median
Day Result
30 d Median
Day Result
30 d Median
3-Jul-06
44   0   0   0   14   0  
11-Jul-06
0   2   2   0   0   0  
13-Jul-06
2   6   6   2   2   2  
19-Jul-06
24   0   0   0   14   0  
27-Jul-06
0 2 0 0 0 0 0 0 12 12 0 0
3-Aug-06
0 0 0 0 0 0 0 0 0 2 0 0
9-Aug-06
12 2 6 0 6 0 0 0 4 4 0 0
15-Aug-06
6 6 0 0 0 0 0 0 16 12 0 0
21-Aug-06
4 4 0 0 0 0 0 0 0 4 0 0
28-Aug-06
6 6 0 0 0 0 0 0 28 4 0 0
1-Sep-06
4 6 0 0 0 0 0 0 2 4 0 0
4-Sep-06
0 4 0 0 0 0 0 0 0 2 0 0
12-Sep-06
0 4 0 0 0 0 0 0 7 2 0 0
20-Sep-06
26 4 2 0 2 0 6 0 160 7 0 0
28-Sep-06
0 0 0 0 0 0 0 0 2 2 2 0
6-Oct-06
0 0 0 0 0 0 0 0 0 2 0 0
12-Oct-06
0 0 2 0 2 0 2 0 0 2 0 0
18-Oct-06
2 0 0 0 0 0 0 0 28 2 0 0
24-Oct-06
6 0 0 0 0 0 0 0 28 2 0 0
30-Oct-06
0 0 0 0 0 0 0 0 4 4 0 0
6-Nov-06
0 0 0 0 0 0 0 0 16 16 2 0
14-Nov-06
2 2 0 0 0 0 0 0 2 16 0 0
22-Nov-06
0 0 0 0 0 0 0 0 10 10 2 0
28-Nov-06
0 0 0 0 0 0 0 0 46 10 0 0
30-Nov-06
0 0 0 0 0 0 0 0 6 10 0 0
7-Dec-06
7 0 0 0 0 0 0 0 7 7 0 0
13-Dec-06
0 0 0 0 0 0 0 0 6 7 0 0
19-Dec-06
0 0 0 0 0 0 0 0 26 7 0 0
27-Dec-06
2 0 0 0 0 0 0 0 19 7 0 0
29-Dec-06
2 2 2 0 0 0 0 0 26 19 2 0
4-Jan-07
12 2 0 0 0 0 0 0 24 24 0 0
12-Jan-07
2 2 2 0 0 0 0 0 27 26 0 0
19-Jan-07
11 2 2 2 0 0 2 0 80 26 20 0
25-Jan-07
2 2 12 2 0 0 0 0 38 27 0 0
31-Jan-07
17 11 2 2 0 0 0 0 0 27 0 0
1-Feb-07
12 11 0 2 0 0 0 0 36 36 0 0
8-Feb-07
0 11 0 2 0 0 0 0 28 36 0 0
14-Feb-07
2 2 0 0 2 0 0 0 16 28 0 0
20-Feb-07
14 12 0 0 10 0 0 0 110 28 0 0
26-Feb-07
150 12 0 0 0 0 0 0 36 36 8 0
6-Mar-07
2 2 0 0 0 0 0 0 45 36 6 0
14-Mar-07
0 2 0 0 0 0 0 0 32 36 0 0
22-Mar-07
0 2 0 0 0 0 0 0 22 36 0 0
30-Mar-07
8 2 2 0 0 0 2 0 26 32 0 0
5-Apr-07
360 2 340 0 40 0 4 0 420 32 2 0
11-Apr-07
0 0 0 0 2 0 0 0 45 32 0 0
17-Apr-07
2 2 0 0 0 0 0 0 14 26 0 0
19-Apr-07
27 8 2 2 6 2 2 2 170 45 0 0
23-Apr-07
2 2 0 0 0 2 0 0 38 45 0 0
1-May-07
70 2 2 0 2 2 0 0 4 38 0 0
9-May-07
36 27 32 2 26 2 34 0 64 38 0 0
17-May-07
60 36 0 2 0 2 0 0 150 64 4 0
25-May-07
54 54 90 2 240 2 2 0 26 38 2 0
31-May-07
12 54 2 2 0 2 0 0 4 26 0 0
6-Jun-07
4 36 0 2 2 2 14 2 27 27 0 0
13-Jun-07
6 12 0 0 2 2 0 0 4 26 0 0
18-Jun-07
0 6 2 2 0 2 2 2 16 16 0 0
19-Jun-07
0 4 8 2 2 2 3 2 10 10 2 0
25-Jun-07
0 0 0 0 0 2 2 2 12 12 0 0

 

Beach Enterococci data (orgs / 100 mL)
State Environmental Protection Policy Waters of Victoria require for primary contact recreation a rolling 30 day median of = 35 Orgs/100 mL and a rolling 60 day 75th Percentile of = 150 orgs/100 mL

 
BEACH 1
BEACH2
BEACH 3
SAMPLE DATE
Day results
30 d Median
75th Percentile
Day Result
30 d Median
75th Percentile
Day Result
30 d Median
75th Percentile
3-Jul-06
35     0     2    
11-Jul-06
2     0     0    
13-Jul-06
2     14     2    
19-Jul-06
4     0     0    
27-Jul-06
0 2   0 0   0 0  
3-Aug-06
2 2   0 0   0 0  
9-Aug-06
2 2   0 0   2 0  
15-Aug-06
2 2   0 0   0 0  
21-Aug-06
0 2   0 0   0 0  
28-Aug-06
2 2   0 0   0 0  
1-Sep-06
0 2 2 0 0 0 0 0 1
4-Sep-06
0 0 2 0 0 0 0 0 0
12-Sep-06
2 0 2 0 0 0 0 0 0
20-Sep-06
0 0 2 3 0 0 6 0 0
28-Sep-06
0 0 2 0 0 0 0 0 0
6-Oct-06
3 0 2 0 0 0 0 0 0
12-Oct-06
0 0 2 2 0 0 0 0 0
18-Oct-06
0 0 2 2 2 1 0 0 0
24-Oct-06
0 0 1 0 0 1 0 0 0
30-Oct-06
0 0 1 0 0 1 0 0 0
6-Nov-06
2 0 1 0 0 1 0 0 0
14-Nov-06
0 0 1 0 0 1 0 0 0
22-Nov-06
0 0 1 0 0 1 2 0 0
28-Nov-06
0 0 0 0 0 1 0 0 0
30-Nov-06
 0 0 0 0 0 0 0 0 0
7-Dec-06
 2 0 1 0 0 0 0 0 0
13-Dec-06
 0 0 0 0 0 0 0 0 0
19-Dec-06
 0 0 0 0 0 0 0 0 0
27-Dec-06
 0 0 0 0 0 0 0 0 0
29-Dec-06
 0 0 0 0 0 0 0 0 0
4-Jan-07
 4 0 1 0 0 0 0 0 4
12-Jan-07
 0 0 0 0 0 0 0 0 0
19-Jan-07
 0 0 0 2 0 0 0 0 0
25-Jan-07
 0 0 0 0 0 0 0 0 0
31-Jan-07
 4 0 1 0 0 0 2 0 0
1-Feb-07
 8 0 3 0 0 0 0 0 0
8-Feb-07
 0 0 2 0 0 0 0 0 0
14-Feb-07
 0 0 2 0 0 0 0 0 0
20-Feb-07
 0 0 2 2 0 0 0 0 0
26-Feb-07
 0 0 2 0 0 0 0 0 0
6-Mar-07
 0 0 2 0 0 0 0 0 0
14-Mar-07
 0 0 0 0 0 0 0 0 0
22-Mar-07
 6 0 2 0 0 0 0 0 0
30-Mar-07
 0 0 2 6 0 0 0 0 0
5-Mar-07
 23 0 5 0 0 0 0 0 0
11-Apr-07
 0 0 3 0 0 0 2 0 0
17-Apr-07
8 6 3 0 0 0 0 0 0
19-Apr-07
2 2 4 0 0 0 0 0 0
23-Apr-07
0 2 4 0 0 0 0 0 0
1-May-07
0 0 4 0 0 0 0 0 0
9-May-07
33 2 7 59 0 0 19 0 0
17-May-07
24 2 15.5 0 0 0 0 0 0
25-May-07
770 24 23.5 930 0 3 1800 0 0
31-May-07
0 24 23.5 0 0 3 0 0 0
6-Jun-07
0 24 23.5 2 2 1 26 19 0
13-Jun-07
2 2 16 0 0 1 0 0 0
18-Jun-07
4 2 16 10 2 6 2 2 0
19-Jun-07
4 2 14 10 2 10 2 2 0
25-Jun-07
0 2 14 0 2 10 8 2 0

 

Beach Enterococci data (orgs / 100 mL)
BEACH4
BEACH5
BEACH6
SAMPLE DATE
Day Result
30 d Median
75th Percentile
Day Result
30 d Median
75th Percentile
Day Result
30 d Median
75th Percentile
3-Jul-06
0     2     2    
11-Jul-06
0     2     0    
13-Jul-06
2     12     4    
19-Jul-06
0     2     0    
27-Jul-06
2 0   0 2   0 0  
3-Aug-06
0 0   0 2   0 0  
9-Aug-06
0 0   0 0   0 0  
15-Aug-06
2 0   86 0   2 0  
21-Aug-06
0 0   0 0   0 0  
28-Aug-06
0 0   0 0   0 0  
1-Sep-06
0 0 1 0 0 2 0 0 1
4-Sep-06
0 0 1 0 0 2 2 0 1
12-Sep-06
0 0 1 2 0 2 0 0 1
20-Sep-06
0 0 0 16 0 2 0 0 0
28-Sep-06
0 0 0 2 2 2 0 0 0
6-Oct-06
0 0 0 0 2 2 0 0 0
12-Oct-06
8 0 0 2 2 2 0 0 0
18-Oct-06
0 0 0 0 2 2 0 0 0
24-Oct-06
0 0 0 10 2 2 0 0 0
30-Oct-06
0 0 0 0 0 2 0 0 0
6-Nov-06
0 0 0 2 2 2 0 0 0
14-Nov-06
0 0 0 6 2 4 0 0 0
22-Nov-06
0 0 0 4 4 5 0 0 0
28-Nov-06
0 0 0 9 4 7.5 0 0 0
30-Nov-06
0 0 0 0 4 5 0 0 0
7-Dec-06
0 0 0 0 4 5 0 0 0
13-Dec-06
0 0 0 2 2 5 0 0 0
19-Dec-06
0 0 0 0 0 5 0 0 0
27-Dec-06
0 0 0 0 0 5 0 0 0
29-Dec-06
0 0 0 4 0 4 0 0 0
4-Jan-07
0 0 0 10 2 5 2 0 0
12-Jan-07
0 0 0 8 4 7 18 0 0
19-Jan-07
2 0 0 4 4 6 0 0 0
25-Jan-07
0 0 0 2 4 6 0 0 0
31-Jan-07
0 0 0 0 4 4 0 0 0
1-Feb-07
0 0 0 7 4 5.5 0 0 0
8-Feb-07
0 0 0 0 2 5.5 0 0 0
14-Feb-07
0 0 0 0 0 5.5 0 0 0
20-Feb-07
0 0 0 0 0 5.5 0 0 0
26-Feb-07
0 0 0 7 0 7 2 0 1
6-Mar-07
0 0 0 2 0 7 0 0 1
14-Mar-07
0 0 0 10 2 7 0 0 0
22-Mar-07
0 0 0 0 2 5.5 0 0 0
30-Mar-07
0 0 0 6 6 6.5 0 0 0
5-Mar-07
0 0 0 16 6 7 0 0 0
11-Apr-07
0 0 0 0 6 7 0 0 0
17-Apr-07
0 0 0 0 0 6.5 0 0 0
19-Apr-07
0 0 0 8 6 7.5 0 0 0
23-Apr-07
0 0 0 0 0 7.5 2 0 0
1-May-07
0 0 0 0 0 7.5 0 0 0
9-May-07
150 0 0 9 0 8.5 2 0 0
17-May-07
0 0 0 26 8 9.5 2 2 1
25-May-07
6 0 0 38 9 12.5 14 2 2
31-May-07
12 6 3 0 9 12.5 0 2 2
6-Jun-07
2 6 4 8 9 12.5 0 2 2
13-Jun-07
0 2 4 4 8 8.5 0 0 2
18-Jun-07
6 6 6 2 4 8.5 0 0 2
19-Jun-07
6 6 6 2 2 8.5 0 0 2
25-Jun-07
170 6 9 7 4 8.5 0 0 2

 

Discharges to air

The Outfall Pump Station engine and the Power Station engine emissions were sampled and tested for nitrogen oxides, carbon monoxide, sulphur dioxide, hydrogen sulphide and Volatile Organic Carbons (VOC) on 6th & 7th June 2007.

The following table contains a comparison between the test results and the licence limits.

Outfall Pump Station Engine

Parameter
Maximum Rate (g/min)
Maximum Concentration (g/m3)
 
Limit
Result
Limit
Result
Hydrogen sulphide
0.5
<0.002
0.002
<0.00003
Nitrogen oxides
500
120