Inland Waters Theme Report
Australia State of the Environment Report 2001 (Theme Report)
Prepared by: Jonas Ball, Sinclair Knight Merz Pty Limited, Authors
Published by CSIRO on behalf of the Department of the Environment and Heritage, 2001
ISBN 0 643 06750 7
Water quality and sources of pollution (continued)
Groundwater pollution (continued)
Condition: The quality of groundwater resources
Contamination of groundwater by nitrates
Nitrate contamination of groundwater (indicated by >10 mg/L nitrate) in Australia is widespread and occurs over regional and local scales (LWRRDC 1999). In many areas, the concentration is greater than the recently revised Australian Drinking Water Guidelines (NHMRC /ARMCANZ 1996) level of 50 mg/L nitrate (as nitrate), resulting in groundwater that is unfit for drinking. In some of the more contaminated areas, the concentration is in excess of 100 mg/L (LWRRDC 1999).
Figure 22 shows the distribution of bores across the nation, with nitrate levels greater than 10 mg/L. The map shows that nitrate concentrations above 10 mg/L (as nitrate) are widespread throughout each state and territory and are found both in undisturbed areas and those affected by human activities.
Figure 22: Distribution of bores across Australia, with nitrate levels greater than 10 mg/L
Source: LWRRDC 1999.
The most effective way of minimising nitrate loads to groundwater is to carefully manage the application of fertilisers for cropping or pasture (LWRRDC 1999). It should be noted that other sources of nitrate contamination are grazing and clearfelling (LWRRDC 1999), and that these are more difficult to manage. There is also potential to reduce nitrate pollution from point sources. Point-source pollution from manufacturing facilities, agricultural processors, landfills and sewage treatment plants can be managed and reduced through licensing and development approval.
Contamination of groundwater by pesticides [IW Indicator 3.5]
Systematic monitoring of pesticide contamination of groundwater in Australia is limited. Recent incidences of reported pesticide contamination of groundwater are listed in Table 26. In most affected areas, pesticides were detected in at least 20% of samples, indicating significant contamination.
| State or territory | Area | Principal contaminant | Percentage of groundwater samples contaminated |
|---|---|---|---|
| Victoria | Shepparton EastC | Atrazine and Simazine | 50 |
| Goulburn-Broken catchment:D Strathmerton-Cobram Shepparton East Nagambie-Mangalore Tongala-Kyabram |
Atrazine and Simazine Atrazine and Simazine Atrazine and Simazine Atrazine and Simazine |
48 49 5 22 |
|
| ArdmonaF | Dieldrin, Chlorpyriphos and Amitrol | n/sA | |
| GirgarreF | No pesticides above ANZECC criteria | ||
| Ky ValleyF | No pesticides above ANZECC criteria | ||
| Western Australia | Kwinana industrial area near PerthK | Herbicides 2,4-D and 2,4,5-T | n/s |
| NSW | Lower Namoi ValleyB | Atrazine | 4 |
| Murray-Riverina catchment: Berriquin Denimein areaD |
Atrazine and Simazine | 16 | |
| Liverpool PlainsE | Atrazine Isolated detections of Simazine, Metolachlor, Trifluraline and Diuron |
40 n/s |
|
| Queensland | Burdekin DeltaC | Atrazine To a lesser extent the Atrazine Degradation |
76 n/s |
| Logan-Albert catchment (SE Qld)J | No pesticides detected | ||
| Border Rivers catchment: Western and MacIntyre sectorsD |
Atrazine and Simazine | 16 | |
| South Australia | PadthawayC | Atrazine and Simazine To a lesser extent the DEA |
60 n/s |
| Piccadilly Valley, near AdelaideI | Atrazine | 5 | |
| Lower south-east of SAG | Dieldrin, Lindane, Chlorpyrifos and Alachlor | 15 | |
| Northern Territory | Darwin rural regionH | No pesticides detected |
A n/s - not stated;B Jiwan and Gates, 1994;C Bauld, 1994;D Bauld et al. 1998;E Timms & Cooper 1998; F Wenig & Lawrence 1998;G Schmidt et al. 1996;H Radke et al. 1998;
I Ivkovic et al. 1998;J Please et al. 1996;K Appleyard 1993.
A 1996 review of pesticides in the Australian environment (Schofield & Simpson 1996) concluded that there were inadequate data on the quantities, locations and types of pesticides used, as well as knowledge gaps in the fate of pesticides in local environments.
Other groundwater pollutants [IW Indicator 3.6]
There is very little publicly available information on groundwater contamination for pollutants other than nitrates and pesticides. It is likely that groundwater contamination is considerably worse than reported below; however, most information is held by private companies or government organisations and is confidential.
Municipal landfills are primarily located in urban areas throughout Australia. Most of the information on groundwater contamination from landfills is contained in private consultants' reports and for this reason, the extent of contamination from landfills is largely unknown. However, waste containment design practices in Australia are continuing to evolve, and with increasing regulatory control and greater scientific understanding and public awareness, landfill designs have improved and the potential for leachates to contaminate groundwater has markedly reduced.
There are many other sources of groundwater contamination and these are listed in Table 30. Groundwater pollutants can take between 10 to 100 years or more to contaminate an aquifer and be detected. The time lag between contamination and its detection is a major issue for the management of groundwater, as often contamination may not be detected until long after the polluting land use has ceased.
| State or territory | Area | Source |
|---|---|---|
| Victoria | Gisbourne 8 sites 6 sites |
Cattle / sheep dips Manufacturing Manufacturing |
| Western Australia | Residential area of PerthA | Effluent from pest control operators - Fenamiphos and Atrazine |
| Kwinana industrial area near PerthB | Effluent from an agrochemical manufacturing plant | |
| NSWC | Mullumbimby Lismore: Goonellabah Lismore: Astenville and Newrybar Rozelle and Hopefield Siding Liverpool PlainsD |
Cattle / sheep dips Cattle / sheep dips Cattle / sheep dips Manufacturing Abandoned chemical drums |
| ACT | No known pesticide contaminated sites | |
| QueenslandE | Unknown | |
| Northern TerritoryF | Darwin Rural area | Manufacturing - Aldrin spill |
| Tasmania | Exeter, Land II | Manufacturing - Dieldrin spill |
A Davis & Appleyard 1996; B Appleyard 1993;C 1603 other cattle/sheep dip sites in NSW have been identified between 1991-92, however, the relationship to these groundwaters has not been assessed (Knight 1993);D Timms & Cooper 1998;E Queensland's 1500 cattle / sheep dip sites are thought to be contaminating soil only. Rarely have groundwater studies been undertaken (Knight 1993); F The Northern Territory is thought to have a number of cattle / sheep dip sites, however, documentation is lacking (Knight 1993).
Source: Adapted from Knight 1993.
| State or territory | Area | Source |
|---|---|---|
| Victoria | 9 sites 2 sites in Melbourne - Geelong region 1 site |
Industrial / manufacturing / storage facilities Landfill Fuel station |
| Western Australia | 8 sites, including 2 sites on the Swan Coastal PlainA | Fuel stations |
| NSW | 5 sites, including Anna Bay, Botany and Matraville 1 site |
Industrial / manufacturing / storage facilities Landfill |
| ACT | 3 sites | Fuel stations |
| Queensland | 1 site in Cairns | Fuel station |
| South Australia | 6 sites: Mt Gambier (2 sites), Bordertown, Jamestown, Fregon and Minlayton | Fuel stations |
| Northern Territory | 1 site: Croker Island | Fuel station |
| Tasmania | Several (number and locations unknown) | Fuel stations |
A The two sites on the Swan Coastal Plain are documented in Davis et al. 1993.
Source: Adapted from Knight 1993.
| State or Territory | Area |
|---|---|
| Victoria | Port Melbourne, West Melbourne, South Melbourne, Melbourne Echuca, Morwell, Heidelberg, Geelong North, Ballarat |
| Western Australia | East Perth 2 sites unidentified |
| NSW | Newcastle and Mortlake Waverton, Little Manly Point, WoollstoncraftB Sydney (5 sites) and Armidale, Tamworth, Casino, Albury, Cootamundra, Goulburn, Lithgow, Bathurst and Orange. |
| Queensland | 6 sites (including 2 in Brisbane) |
A The 17 sites with some documented public record are a small fraction of the total number of gas works sites (>100).
B Groundwater contamination is reported to be minimal at each of the three sites.
Source: Adapted from Knight 1993.
| Activity | Source / type of contamination |
|---|---|
| Monitoring, exploration and production bores | Potential for cross contamination of aquifers. Contaminants can be introduced into the groundwater during drilling of production bores. Improperly constructed bores, corroded bore casings and improperly abandoned bores. |
| Injection bores | Injection wells are used to discharge liquid wastes and other liquids into subsurface zones below the water table. Liquids that are injected include: hazardous wastes, brine from oil wells, agricultural and urban run-off, municipal sewerage, air-conditioning return water, heat pump return water, liquids used for enhanced oil recovery from oil fields, treated water intended for artificial aquifer recharge and fluids used in solution mining. |
| Atmospheric pollutants | Sources include automobile emissions, power plant smokestacks, incinerators and other industrial processes. Pollutants from these sources include; hydrocarbons, organic chemicals, heavy metals, sulfur and nitrogen compounds. Infiltration may carry these compounds to the groundwater. |
| Urban run-off | High amounts of dissolved and suspended solids from auto emissions, fluid leaks from vehicles, home use of fertilisers/pesticides, refuse and pet faeces can infiltrate groundwater from leaking storm sewers. |
| Material transport and transfer | Spills during material transport and transfer may result from accidents, and leaks can occur due to faulty equipment. A wide variety of materials can be released and infiltrate groundwater from these processes. |
| Fire-fighting | Disposal and seepage of contaminated fire fighting water. |
| Pipelines | Pipelines (i.e. sewers, natural gas, petroleum products etc) have the potential to leak and release contaminants to the groundwater. Old pipelines and steel pipelines subjected to corrosion are particularly of concern. |
| CemeteriesA | Common groundwater contaminants sourced from cemeteries include nitrate, ammonia, bacteria and a range of inorganic substances. In 1996 the National Survey of Cemetery Groundwaters began to assess general hydrogeochemical and microbiological conditions at 9 cemeteries across Australia. |
A Dent & Knight 1998.
Source: Adapted from Fetter 1992.