Human Settlements Theme Report

Australia State of the Environment Report 2001 (Theme Report)
Lead Author: Professor Peter W. Newton, CSIRO Building, Construction and Engineering, Authors
Published by CSIRO on behalf of the Department of the Environment and Heritage, 2001
ISBN 0 643 06747 7

Waste, recycling and reuse (continued)

Wastewater

Wastewater collection

Wastewater is water which has been used for some purpose and would normally be treated or discarded; wastewater often contains significant quantities of pollutants.

WSAA (2000) provided information on the volumes of wastewater collected by major urban water authorities (Table 63). But there is a lack of consistency in the method of categorising the sources of wastewater collected by each authority; so it is difficult to draw conclusions about the relative importance of each segment.

Table 63: Wastewater collected by major urban authorities, 1999-2000 (ML). [HS Indicator 2.5]
Water business	Residential and non-trade waste	Trade waste	Infiltration	Bulk receivables	Other	Total
ACT Electricity and Water Corporation	-	3 200	2 666	-	27 882	33 748
Barwon Water (Vic)	15 054	2 456	2 388	5	-	19 903
Brisbane City Council (Qld)	91 166	10 000	15 791	16	-	116 973
Central Gippsland Water (Vic)	6 581	11 038	-	-	9 150	26 769
Central Highlands Water (Vic)	8 659	1 325	459	-	-	10 443
City West Water (Vic)	72 200	22 750	10 600	-	50	105 600
Coliban Water (Vic)	-	-	-	-	10 560	10 560
Gold Coast Water (Qld)	46 111	2 400	-	-	-	48 511
Gosford City Council (NSW)	12 009	1 600	1 825	-	-	15 434
Goulburn Valley Water (Vic)	8 276	5 411	1 856	6	1	15 550
Hunter Water Corporation (NSW)	-	3 430	-	-	62 450	65 880
Power and Water Authority-Darwin (NT)	-	-	5 700	-	11 934	17 634
SA Water Corporation-Adelaide	70 796	23 599	-	-	-	94 395
South East Water Limited (Vic)	96 195	6 717	11 058	35	-	114 005
Sydney Water Corporation (NSW)	432 770	38 100	55 241	12	-	526 123
Water Corporation-Perth (WA)	-	-	-	-	97 279	97 279
Yarra Valley Water (Vic)	-	16 768	10 296	-	104 311	131 375
Total	859 817	148 794	117 880	74	323 617	1 450 182

Note: Because of different reporting procedures used by the water authorities, values cannot be determined for certain sources of wastewater collected by some authorities. Residential and non-trade waste is the wastewater discharge from residential and other properties that does not require a trade waste license. Trade waste is the licensed industrial and commercial trade waste discharged to the wastewater system. Bulk receivables are delivered to the treatment plant by means other than the sewerage pipe network.

Source:WSAA (2000).

Wastewater discharges to the environment

Comprehensive data on wastewater disposal methods is available for 1994 only and is presented in Table 64. A comparison of the values given in the right-hand column of the table with data compiled by the ABS (2000f) (Table 66) implies that volumes of wastewater reported by Thomas et al. (1997) relate to those handled by water authorities only. The majority of wastewater is disposed to coastal waters (72%); inland waters received 17% of wastewater in 1994, while land disposal was used for 10% of the total.

Table 64: Wastewater disposal method by volume, 1994 (ML). [HS Indicator 2.4]
State or territory	Disposal method				Total
	Coastal waters	Inland waters	Land	Direct reuse
Australian Capital Territory	0	32 969	30	1	33 000
New South Wales	443 137	138 293	28 198	8 710	618 338
Northern Territory	9 090	1 100	1 250	0	11 440
Queensland	240 320	31 810	30 660	1 220	304 010
South Australia	93 478	1 548	6 819	2 881	104 726
Tasmania	35 000	14 390	0	910	50 300
Victoria	326 580	74 071	82 191	958	483 800
Western Australia	76 765	875	12 790	3 382	93 812
Total	1 224 370	295 056	161 938	18 062	1 699 426
Percentage of total	72%	17.5%	9.5%	1%	100%

Source: Thomas et al. (1997).

According to the available data, only 1% of the total wastewater was reused in 1994. Western Australia reused the greatest proportion of its wastewater output, while New South Wales reused the greatest amount in terms of volume (48% of the national total).

Thomas et al. (1997) compiled data on wastewater disposal methods by volume expected in 2000 (see Table 65). As was the case in 1994, most wastewater was expected to be disposed of to coastal waters (71%). In a reversal from 1994 values, inland waters were expected to receive 9% of wastewater, while land disposal was expected to account for 17% of the total. Wastewater reuse in 2000 was predicted to increase 150% to 2.5% nationally. Thomas et al. (1997) stated that projections for direct reuse should be taken as minimums, based on confirmed schemes or adopted targets at the state and territory level. A survey conducted by Dillon (2000) found that during the 1996-1999 period wastewater reuse from wastewater treatment plants was in the order of 7% nationally, exceeding the projected minimum value of Thomas et al. (1997) (see Utilising wastewater as a resource).

Table 65: Expected wastewater disposal method by volume, 2000 (ML). [HS Indicator 2.4]
State or territory	Disposal method				Total
	Coastal waters	Inland waters	Land	Direct reuse
Australian Capital Territory	0	37 945	2 050	5	40 000
New South Wales	448 088	33 427	157 593	23 851	662 959
Northern Territory	13 300	1 100	1 600	0	16 000
Queensland	266 034	35 214	33 941	1 351	336 540
South Australia	96 120	1 548	7 134	2 881	107 683
Tasmania	36 566	15 031	0	955	52 552
Victoria	385 901	46 306	99 748	1 345	533 300
Western Australia	78 651	0	16 317	17 046	112 014
Percentage of total	71%	9%	17%	2.5%	100%
Total	1 324 660	170 571	318 383	47 434	1 861 048

Source: Thomas et al. (1997).

The volume of wastewater to be disposed of in all states and territories was predicted to increase between 1994 and 2000, with the greatest rise (40%) in the Northern Territory and the smallest rise (3%) in South Australia. On a national basis there was a predicted 10% increase in wastewater for disposal.