Reclaimed Water Use in Livestock Production

Note Number: AG1090
Published: February 2003
Updated: May 2009

Although the term reclaimed water can apply to a broad range of water sources, in this Agriculture Note it is used in the context of water derived from sewerage systems and treated to a standard that is appropriate for its intended use, such as in livestock production.

Reclaimed water is a potentially valuable resource for the agricultural sector. Properly used, reclaimed water is protective of the environment, public and animal health and food safety, and may also have advantages over the use of potentially limited or costly traditional primary water sources in terms of reliability of supply and price.

This Agriculture Note provides general advice on the use of reclaimed water for livestock production.

Legal requirements

The Livestock Disease Control Act 1994 prohibits the use of water from sewerage systems in cattle or pig production unless it has been treated to an acceptable standard.

Under the Environmental Protection Act 1970, discharges from water treatment systems to the environment must be managed so as to not adversely impact the receiving environment. The use of reclaimed water must comply with EPA guidelines, otherwise formal EPA licensing of the reuse site is required.

Hazards in sewerage water

Inadequately treated water from sewerage systems poses a risk to human and animal health if it is applied to pasture or fodder crops grazed by livestock or otherwise consumed. Inadequately treated water may contain bacteria, viruses, protozoa and helminth eggs that would be a risk to the livestock, or to humans who have contact with or consume livestock products.

Of particular specific concern in sewerage water, are eggs of the tapeworms Taenia solium and Taenia saginata which cause pork measles and beef measles respectively when consumed by pigs or cattle. Humans can become infected with these tapeworms if the life-cycle of the parasite is completed by consumption of infected and poorly cooked pork or beef.

Treatment to reclaim sewerage water

In Victoria, water from Municipal sewerage treatment plants is treated by a combination of disinfection and either secondary or tertiary processes.  Treatment methods include lagooning, filtration, chemical treatment (eg chlorine) and UV disinfection.

Four classes of reclaimed water (A, B, C and D see Table 1) are recognised in EPA Victorias Guidelines for Environmental Management (GEM): Use of Reclaimed Water, based on a combination of prescribed treatment processes and microbiological criteria (primarily bacterial) for the treated water. The treatment grade affects the appropriateness of the water for use in livestock production and the necessary management controls.  In addition, reclaimed water intended for use with cattle must have had treatment to remove helminth parasites; such treatment is based on lagooning for a period of 25 days or longer or an approved method of filtration such as sand or membrane filtration.

The treatment standards reflect the necessary pathogen reduction to protect livestock health and food safety.

It is important for the supplier and user to establish clearly the quality of reclaimed water supplied to the farm, and for the user to comply with any restrictions or withholding periods that may apply.

Opportunities for use of reclaimed water

The controls on the use of reclaimed water in livestock production are primarily dictated by the quality of the water (class and helminth treatment), with key controls being restrictions on the type of livestock and the potential need for observance of brief withholding periods (summarised in Table 2). The EPA guideline requires management controls to be documented in an Environment Improvement Plan.

A brief summary of recommended usage follows.

Cattle

Any reclaimed water for use by cattle must have received effective helminth removal at the treatment plant. Class A water may be used by cattle without restriction. Class B and class C water may be safely used when supplemented by some additional pathogen reduction strategies (Refer Agriculture Note: Reclaimed water use in cattle production). The controls are more stringent for lactating dairy cattle compared to beef cattle.

Pigs

Reclaimed sewerage water of any class must not be used as drinking water for pigs or applied to crops or pasture grazed by pigs, or processed into fodder for consumption by pigs.  No treatment standard has been approved for pigs.

[Note: this is in part because of the seriousness of human infection with Taenia solium, which can cause severe neurological disease in people. Although pork measles (cysticercosis) has not been detected in pigs in Australia, the tapeworm is known to affect some people who have lived or visited overseas, and it is important that exposure to pigs is prevented.]

Other grazing animals (eg horses, alpacas, deer )

For other species (ie other than pigs and cattle) helminth treatment is not essential, as there is no comparable sewage-derived parasitic condition in these species. Nevertheless, it is important to consider the potential effects where the proposed use of land may change.

Further information

Comprehensive guidance on agricultural use of reclaimed water may be found in two publications that can be downloaded from the EPA:

GEM Use of Reclaimed Water (EPA Victoria, 2002 publication 464.1).

GEM Disinfection of Treated Wastewater (EPA Victoria, 2002 publication 730).

Agriculture Notes, AG1089: "Reclaimed water use in cattle production"

Further information is also available from animal health staff in your local DPI office, call 136186.

Acknowledgements

This Agnote was developed by Andrew Cameron February 2003.
I t was reviewed by Andrew Cameron Biosecurity Victoria, May 2009.

Tables

#  For use in cattle production water must also have received an effective helminth treatment