Sources of water for poultry

Water sources used by the Australian poultry industry are varied and also differ between states and territories and between rural and urban localities. Primary water sources for supply to poultry include:

• mains or town water
  
  
• bore or underground water
  
  
• surface water
  
  
• rain water.
  
  

1.1 Mains or town water

Unlike chicken meat farms, commercial layer farms tend not to be centrally located and tend not to use (or have access to) mains or town water supplies. For poultry species other than chickens, mains or non-mains water supply may be used.

Mains water is generally treated and sanitised prior to distribution and is therefore the preferred and most biosecure water for poultry. Sanitation of mains water at the farm site is uncommon, although some producers may choose to use a sanitiser to control biofilm and other non-specific microbial build-up in drinking or cooling systems. On occasion, mains water has been found to have high levels of coliforms requiring treatment (such as treating the mains supply with chlorination). With reduced water availability in many areas of Australia, restrictions have been put on some intensive livestock and industrial  facilities to reduce mains water use. This has necessitated the use of alternatives such as bore or surface water.

Some water authorities also mandate that poultry farms can only access prescribed flow rates (litres per second) from the mains supply. This requires producers to use farm water storage with site distribution via pumps, in order to provide additional water in times of higher demand.

1.2 Bore water (underground water)

The use of underground water is common in Australia, particularly where the quality (especially the salinity) is suitable for use in poultry. The suitability of bore water varies significantly between localities, with some areas such as south-east Queensland generally being favourable, while others such as North and North-central Victoria are variable. The state departments of primary industry can provide information on water quality for some localities.

Underground water is usually considered to have a very low risk of containing avian pathogens, so on-farm sanitation is uncommon for this water source. Shallow bores or spring water, however, may be affected by surface run-off and can, particularly after heavy rains, contain levels of coliforms including E. coli. The presence of E. coli indicates faecal matter, such as from grazing animals, has contaminated the bore through surface run-off.

The treatment of bore water by methods  including desalination (reverse osmosis) to reduce high salinity can be undertaken using existing and improving technology. However, a thorough knowledge of the technical aspects of water treatment technology, bore operation and environmental aspects is essential. Access to bore water generally requires a license from the local catchment or water authority, an extraction permit and an allocation allowance. Often this allocation may need to be traded or offset  against existing allowances from other supply sources.

It is also necessary to maintain farm storage of bore water, particularly where flow rates are below peak demand or the water has been previously treated. This storage may be sealed or, in some cases, pumped directly into open water storage such as a dam. Bore water stored in the open should be considered a non-secure source of water that can be contaminated with avian pathogens such as AI viruses.

1.3 Surface water (dams, reservoirs, channel, rivers and  streams)

Surface water provides the highest risk for potential contamination with avian pathogens, particularly those associated with aquatic water birds such as AI and EDS viruses and bacteria associated with water run-off, such as E. coli, Campylobacter spp.and Salmonella spp. Effective sanitation of surface water is required to reduce the risk of an  EAD in poultry.

Surface water that provides a permanent or transient habitat for waterfowl, particularly the Anseriformes (ducks, geese, swans) or Charadriiformes (shorebirds), is at highest risk of contamination with AI virus.

The methods required to effectively sanitise surface water and eliminate avian pathogens are generally more technically complex than thought by water users. Factors influencing the effectiveness of surface water sanitation include:

• the avian pathogen involved|
  
  
• the quality of the water and its organic  load, pH and solutes
  
  
• the sanitiser used|
  
  
• the contact time between the sanitiser  and the water
  
  
• the turbidity of the water.
  
  

Even after these aspects are considered and  addressed there are mechanical, maintenance and monitoring factors that can also influence the effectiveness of water sanitation.

1.4 Other sources (rain water, carted water, recycled water)

The origin of alternative water sources should be identified in order to evaluate their biosecurity risk. For instance, water carted from a secure mains supply is associated with much lower risk than water from a lake or dam. With this knowledge,  the necessary actions should be taken to ensure that the water is a secure and biologically safe supply for poultry. Other horizontal contacts such as vehicular and  personnel movements should also be assessed for their biosecurity risk.