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) 455 609 660
Suspended Solids (mg/L) 495 885 1400
pH (pH units) 7.1 7.5 9.0
Ammonia as N (mg/L) 42 45 51
Total Combined Nitrogen (mg/L) 75 88 140
Total Phosphorus (mg/L) 15 20 27
Anionic Surfactants MBAS (mg/L) 4.4 7.4 9.3
Cadmium (mg/L) 0.0005 0.0009 0.0036
Chromium (mg/L) 0.02 0.040 0.13
Copper (mg/L) 0.13 0.24 0.45
Lead (mg/L) 0.008 0.015 0.025
Mercury (mg/L)2 0.00052 0.00032 0.00132
Phenol (g/L) 702 2502 3002
Toluene (g/L) 2.02 16.62 502
Benzene (g/L) 0.52 0.52 502
PAH's total (g/L) 0.142,3 0.232,3 0.252,3

Notes:

  1. 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.
  2. 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 Truemans Rd and flow measurements at the Eastern Treatment Plant from 1 July 2007 to 30 June 2008.

Parameter (units)
Median
90th Percentile
Maximum
Licence Limit
Result
Licence Limit
Result
Licence Limit
Result
BOD5 (mg/L) NS 7 NS 22 NS 32
CBOD5 (mg/L) 20 3 40 6 NS 16
Suspended Solids (mg/L) 30 11 60 22 NS 100
pH (pH units) NS 7 NS 8 ≥6, ≤9 8.1
Ammonia as N (mg/L)
(Truemans Rd)
30 1.8 NS 11 40 19
Ammonia as N (mg/L)
(final effluent at ETP)
5 2.4 NS 12.9 NS 19
Total Nitrogen (mg/L) NS 16.5 NS 25 NS 27
Total Phosphorus (mg/L) NS 8.3 15 9.8 NS 11
Anionic Surfactants (mg/L) 0.4 0.1 0.7 0.26 NS 0.57
Cadmium (mg/L)1 NS 0.0001 0.005 0.0001 0.01 0.0001
Chromium (mg/L) NS 0.003 0.075 0.005 0.15 0.007
Copper (mg/L) NS 0.015 0.05 0.015 0.1 0.048
Lead (mg/L)1 NS 0.0005 0.05 0.0006 0.1 0.003
Mercury (mg/L)1 NS 0.00005 0.0005 0.00005 0.001 0.00005
Phenol (g/L) NS 0.5 NS 4.6 100 5.0
Toluene (g/L) NS 0.5 NS 0.5 50 0.5
Benzene (g/L) NS 0.5 NS 0.5 25 0.5
PAH's total (g/L)2 NS 0.13 NS 0.23 15 0.25
ETP discharge (ML/day)3 NS 300 NS 364 NS 521
Outfall discharge (ML/day)4 540 300 NS 373 NS 544
Total Residual Chlorine (mg/L) NS 0.12 NS 0.27 1.0 0.42
E.coli (orgs/100mL) 200 23 1000 118 NS 2500
Enterococci (orgs/100ml) NS 7 NS 39 NS 1300
Dissolved Oxygen (mg/L) NS 7.2 NS 8.4 ≥ 6.0 6.0 - 8.5

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. colimedian org/100mL BOD5mg/L
Median
CBOD5mg/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 6 6.0 3 12 7.0 - 8.0
Ballarto Rd Sample Point (SEO Manhole No. 069) 3 7 3 12 7.0 - 8.0
Range Rd Sample Point (SEO Manhole No. 035) 2 7 3 9 7.0 - 8.0
Trumans Rd Gunnamatta (SEO Manhole No. 003) 23 7 3 11 7.0 - 8.1
  1. Eastern Treatment Plant Reuse sample point

Effluentflow to the outfall

Daily and monthly median and maximum flows (ML/day) were measured during 2007/08. Monthly median and maximums are shown below. The total outfall flows for 2007/08 are as follows:

Description
Flow (ML)
Comment
ETP Outflow
112,202
Total outfall pump station flow minus internal plant use
Calculated outfall flow
112,990
Boags Rocks Outfall flow (ETP plus South East Water treatment plant flows, less water recycling)

Month
Median (ML/d)
Maximum (ML/d)
July 2007
341
515
August 2007
282
437
September 2007
309
490
October 2007
307
360
November 2007
319
520
December 2007
312
521
January 2008
269
343
February 2008
327
433
March 2008
262
460
April 2008
267
334
May 2008
284
365
June 2008
330
411

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-07
8   0   0   2   18   0  
11-Jul-07
0   2   0   2   7   0  
19-Jul-07
0   0   0   0   34   0  
24-Jul-07
6   0   2   0   14   0  
27-Jul-07
10 6 10 0 0 0 20 2 20 18 0 0
2-Aug-07
0 0 0 0 68 0 0 0 50 20 0 0
8-Aug-07
2 2 0 0 0 0 0 0 0 20 0 0
14-Aug-07
58 6 34 0 150 2 0 0 0 14 0 0
20-Aug-07
0 2 0 0 0 0 0 0 16 16 2 0
28-Aug-07
4 2 0 0 0 0 0 0 5 5 0 0
5-Sep-07
0 2 0 0 0 0 0 0 3 3 0 0
13-Sep-07
2 2 0 0 0 0 0 0 0 3 0 0
21-Sep-07
0 0 0 0 0 0 0 0 0 3 0 0
27-Sep-07
0 0 0 0 0 0 0 0 0 0 0 0
3-Oct-07
2 0 2 0 0 0 2 0 14 0 2 0
9-Oct-07
0 0 0 0 0 0 0 0 8 0 0 0
15-Oct-07
0 0 0 0 0 0 2 0 0 0 0 0
23-Oct-07
2 0 0 0 2 0 0 0 10 8 0 0
31-Oct-07
0 0 0 0 2 0 0 0 2 8 0 0
7-Nov-07
2 0 0 0 0 0 0 0 6 6 0 0
12-Nov-07
4 2 0 0 0 0 0 0 18 6 2 0
20-Nov-07
4 2 0 0 0 0 0 0 18 10 0 0
28-Nov-07
10 4 0 0 0 0 0 0 7 7 0 0
30-Nov-07
0 4 0 0 0 0 0 0 50 18 2 0
5-Dec-07
0 4 0 0 0 0 0 0 13 18 0 0
11-Dec-07
0 0 0 0 0 0 0 0 10 13 0 0
19-Dec-07
6 0 0 0 0 0 0 0 34 13 0 0
27-Dec-07
5 0 0 0 0 0 0 0 190 34 0 0
2-Jan-08
0 0 0 0 0 0 0 0 420 34 2 0
9-Jan-08
11 5 0 0 0 0 0 0 120 120 0 0
16-Jan-08
6 6 0 0 0 0 0 0 130 130 3 0
23-Jan-08
2 5 0 0 0 0 0 0 24 130 0 0
30-Jan-08
2 2 0 0 0 0 0 0 330 130 2 2
6-Feb-08
4 4 0 0 0 0 0 0 120 120 6 2
13-Feb-08
0 2 0 0 0 0 0 0 11 120 6 3
21-Feb-08
4 2 0 0 0 0 0 0 260 120 0 2
27-Feb-08
10 4 0 0 0 0 0 0 16 120 0 2
5-Mar-08
0 4 0 0 0 0 0 0 24 24 0 0
12-Mar-08
100 4 0 0 0 0 0 0 44 24 0 0
19-Mar-08
0 4 0 0 0 0 0 0 17 24 0 0
26-Mar-08
34 10 8 0 4 0 8 0 86 24 4 0
2-Apr-08
4 4 0 0 0 0 0 0 2 24 0 0
9-Apr-08
30 30 2 0 0 0 0 0 0 17 0 0
16-Apr-08
2 4 0 0 0 0 0 0 6 6 0 0
23-Apr-08
21 21 0 0 0 0 0 0 16 6 0 0
30-Apr-08
8 8 0 0 0 0 0 0 0 2 0 0
7-May-08
0 8 4 0 2 0 0 0 8 6 0 0
14-May-08
2 2 0 0 0 0 0 0 0 6 0 0
21-May-08
4 4 2 0 14 0 0 0 6 6 0 0
28-May-08
4 4 0 0 2 2 6 0 0 0 0 0
4-Jun-08
0 2 4 2 4 2 0 0 8 6 2 0
11-Jun-08
0 2 0 0 2 2 0 0 14 6 0 0
18-Jun-08
0 0 0 0 0 2 0 0 0 6 0 0
25-Jun-08
0 0 2 0 0 2 0 0 2 2 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
%ile
Day Result
30 d Median
75th
%ile
Day Result
30 d Median
75th
%ile
3-Jul-07
0     0     0    
11-Jul-07
0     9     0    
19-Jul-07
0     2     0    
24-Jul-07
0     0     2    
27-Jul-07
10 0   34 2   0 0  
2-Aug-07
120 0   47 9   46 0  
8-Aug-07
13 10   2 2   0 0  
14-Aug-07
310 13   790 34   550 2  
20-Aug-07
0 13   0 34   0 0  
28-Aug-07
16 16   0 2   0 0  
5-Sep-07
0 13 14.5 0 0 21.5 3 0 2.5
13-Sep-07
0 0 14.5 0 0 21.5 2 2 2.5
21-Sep-07
0 0 14.5 0 0 18 0 0 2.5
27-Sep-07
0 0 14.5 0 0 18 0 0 2.5
3-Oct-07
0 0 14.5 0 0 18 0 0 2.5
9-Oct-07
0 0 14.5 0 0 1 0 0 2.5
15-Oct-07
0 0 6.5 0 0 0 0 0 1
23-Oct-07
0 0 0 0 0 0 0 0 1
31-Oct-07
0 0 0 0 0 0 0 0 0
7-Nov-07
0 0 0 0 0 0 0 0 0
12-Nov-07
0 0 0 0 0 0 0 0 0
20-Nov-07
0 0 0 0 0 0 0 0 0
28-Nov-07
2 0 0 0 0 0 0 0 0
30-Nov-07
0 0 0 2 0 0 0 0 0
5-Dec-07
0 0 0 0 0 0 0 0 0
11-Dec-07
2 0 0 0 0 0 2 0 0
19-Dec-07
0 0 0 0 0 0 0 0 0
27-Dec-07
4 0 1 3 0 0 0 0 0
2-Jan-08
4 2 2 0 0 0 2 0 0
9-Jan-08
2 2 2 0 0 0 0 0 0
16-Jan-08
4 4 3 0 0 0 0 0 4
23-Jan-08
0 4 3 0 0 0 0 0 0
30-Jan-08
2 2 3 0 0 0 0 0 0
6-Feb-08
5 2 4 0 0 0 0 0 0
13-Feb-08
0 2 4 0 0 0 0 0 0
21-Feb-08
0 0 4 0 0 0 0 0 0
27-Feb-08
4 2 4 0 0 0 0 0 0
5-Mar-08
0 0 4 0 0 0 0 0 0
12-Mar-08
2 0 4 0 0 0 0 0 0
19-Mar-08
0 0 3 0 0 0 0 0 0
26-Mar-08
4 2 4 0 0 0 0 0 0
2-Apr-08
0 0 3 0 0 0 0 0 0
9-Apr-08
5 2 4 0 0 0 0 0 0
16-Apr-08
0 0 4 0 0 0 0 0 0
23-Apr-08
8 4 4 0 0 0 0 0 0
30-Apr-08
0 0 4 0 0 0 0 0 0
7-May-08
2 2 4 0 0 0 0 0 0
14-May-08
0 0 3 0 0 0 0 0 0
21-May-08
0 0 3 0 0 0 2 0 0
28-May-08
6 0 4.5 0 0 0 0 0 0
4-Jun-08
2 2 4.5 2 0 0 4 0 0
11-Jun-08
0 0 3.5 0 0 0 0 0 0
18-Jun-08
0 0 3.5 0 0 0 0 0 0
25-Jun-08
4 2 3 2 0 0 0 0 0

Beach Enterococci data (orgs / 100 mL)

BEACH4
BEACH5
BEACH6
SAMPLE DATE
Day Result
30 d Median
75th
%ile
Day Result
30 d Median
75th
%ile
Day Result
30 d Median
75th
%ile
3-Jul-07
2     10     0    
11-Jul-07
6     0     0    
19-Jul-07
0     42     2    
24-Jul-07
0     4     0    
27-Jul-07
90 2   130 10   2 0  
2-Aug-07
58 6   94 42   4 2  
8-Aug-07
16 16   8 42   0 2  
14-Aug-07
49 49   30 30   39 2  
20-Aug-07
0 49   0 30   14 4  
28-Aug-07
0 16   40 30   0 4  
5-Sep-07
0 0 32.5 0 8 41 0 0 3
13-Sep-07
0 0 32.5 0 0 41 0 0 3
21-Sep-07
0 0 32.5 0 0 41 0 0 3
27-Sep-07
0 0 32.5 0 0 35 0 0 3
3-Oct-07
0 0 32.5 6 0 35 0 0 3
9-Oct-07
0 0 8 2 0 19 0 0 2
15-Oct-07
0 0 0 0 0 7 0 0 0
23-Oct-07
0 0 0 0 0 4 0 0 0
31-Oct-07
0 0 0 0 0 1 0 0 0
7-Nov-07
0 0 0 4 0 3 0 0 0
12-Nov-07
0 0 0 6 0 3 2 0 0
20-Nov-07
0 0 0 32 4 5 0 0 0
28-Nov-07
0 0 0 4 4 5 0 0 0
30-Nov-07
0 0 0 10 6 6 0 0 0
5-Dec-07
0 0 0 2 6 6 0 0 0
11-Dec-07
0 0 0 0 4 5 0 0 0
19-Dec-07
0 0 0 4 4 5 0 0 0
27-Dec-07
0 0 0 65 4 8 0 0 0
2-Jan-08
0 0 0 53 4 21 6 0 0
9-Jan-08
0 0 0 78 53 42.5 0 0 0
16-Jan-08
0 0 0 32 53 42.5 20 0 1
23-Jan-08
2 0 0 20 53 42.5 3 3 1.5
30-Jan-08
0 0 0 39 39 46 0 3 1.5
6-Feb-08
0 0 0 0 32 46 0 0 1.5
13-Feb-08
0 0 0 0 20 46 0 0 1.5
21-Feb-08
0 0 0 28 20 46 0 0 1.5
27-Feb-08
0 0 0 0 0 46 0 0 1.5
5-Mar-08
0 0 0 2 0 46 2 0 2.5
12-Mar-08
0 0 0 6 2 35.5 8 0 4.5
19-Mar-08
0 0 0 0 2 30 6 2 4.5
26-Mar-08
0 0 0 7 2 24 0 2 4.5
2-Apr-08
0 0 0 2 2 13.5 0 2 2.5
9-Apr-08
0 0 0 0 2 6.5 0 0 1
16-Apr-08
0 0 0 2 2 4 0 0 1
23-Apr-08
0 0 0 0 2 4 0 0 1
30-Apr-08
0 0 0 0 0 4 0 0 1
7-May-08
0 0 0 2 0 2 0 0 1
14-May-08
0 0 0 0 0 2 0 0 1
21-May-08
2 0 0 0 0 2 0 0 0
28-May-08
0 0 0 0 0 2 0 0 0
4-Jun-08
0 0 0 2 0 2 0 0 0
11-Jun-08
0 0 0 0 0 2 0 0 0
18-Jun-08
0 0 0 0 0 1 0 0 0
25-Jun-08
2 0 0 0 0 1 0 0 0

Discharges to air

Outfall Pump Station Engine

The EPA Victoria discharge licence for the Eastern Treatment Plant requires that annual monitoring of at least one of the five outfall pump engine stacks when operating on sludge gas.

As part of the Eastern Green Energy Project, Melbourne water replaced three of its five outfall pump engines in 2006/07, with electrical motors thus eliminating emissions from the outfall pump station during normal operation. In 2007/08, Melbourne water converted the remaining two engines to operate on natural gas with 10 % diesel pilot fuel. These two engines will be used only during emergencies and breakdowns.

As there was no outfall engine operating on sludge gas, no sampling was conducted for outfall pump engine emission, as agreed by EPA.

Power Station Engine

During 2007/08, sludge gas was used primarily for the operation of the power engines in the power station.