Indicator: Drinking Water Quality
Drinking water quality in the ACT improved during the reporting period, despite the bushfires of January 2003, which burnt a large part of the Cotter Catchment. ACT Health introduced the Drinking Water Quality Code of Practice in March 2000 and ActewAGL, the licensed provider of water in the ACT, is required to adhere to protocols laid out in the code.
What the results tell us for the ACT
Drinking water in the ACT is mainly sourced from the Cotter Catchment and is supplemented by water from the Googong Catchment through Googong Dam in New South Wales.
Bushfires affected water quality in dams and rivers
The Cotter Catchment was severely disturbed by the bushfires in January 2003, and heavy rain in March–April 2003 washed contaminants into the Bendora and Corin Reservoirs. As a result, Bendora Dam was closed on 8 April 2003, and was not reopened by the end of the reporting period. Water has since been taken from the Googong Catchment. Googong water needs a higher level of treatment than Cotter water as the catchment is subject to human and domestic animal activities.
The loss of canopy and ground cover during the bushfires also left the Cotter Catchment vulnerable to erosion of soil and fire debris. ActewAGL estimates that it ‘could take up to 50 years for sphagnum swamps to recover fully, and they will require protection and careful management to save it [the ecosystem] from permanent destruction’ (ActewAGL 2003).
Drought, fire and water restrictions
The continuing lack of rain in the reporting period also resulted in the ACT Government introducing voluntary water restrictions in December 2002, with Stage 2 restrictions in April 2003.
Mixed trends in drinking water quality
The microbiological quality of drinking water in the ACT improved during the reporting period, after a variable performance in the previous reporting period. Total coliform (intestinal microbe) levels improved in each year of this period: 2000–01 (98.7% of samples were within acceptable standards), 2001–02 (99.1% of samples) and 2002–03 (99.6%).
These figures are certainly better than the 1998–99 and 1999–2000 figures reported in the State of the Environment Report 2000(93.7% and 94.8% respectively). Only two of 1924 samples tested from July 2000 to June 2003 failed to meet National Health and Medical Research Council guidelines for levels of faecal coliforms.
Failures to meet aesthetic guidelines for drinking water were recorded in all three years of the reporting period. These failures were mainly due to the presence of aluminium, iron and manganese, with colour and turbidity also outside acceptable levels on rare occasions (see the tables in the downloadable pdf, linked from the top of the page).
New code of practice
In March 2000, the ACT Department of Health introduced a Drinking Water Quality Code of Practice. It sets out the protocols for drinking water quality, incident notification and incident responses. The code uses as its standard the Australian Drinking Water Guidelines, taking into account local conditions and influences.
Data sources and references
Commissioner for the Environment, Australian Capital Region State of the Environment Report 2000 , Canberra, ACT.
ActewAGL, Drinking Water Quality Reports , 2000– 01, 2001–02, 2002–03.
ACT Health, Drinking Water Quality Code of Practice 2000 .