Reclaimed Water – Use in Cattle Production
Note Number: AG1089
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 a summary of advice on the use of reclaimed water in cattle production systems.
Legal requirements
The Livestock Disease Control Act 1994 prohibits the use of water from sewerage systems in cattle production unless it has been treated to an acceptable standard.
Under the Environmental Protection Act 1970, discharges of water from treatment systems to the environment must be managed so as not to 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 untreated sewerage water
Untreated sewage potentially contains a range of pathogenic organisms that may pose a risk to the health of both livestock and humans. The potential pathogens include viruses (eg enteric viruses), bacteria (eg Salmonella and Shigella species), protozoa (eg Giardia species) and helminths (eg eggs of Taenia tapeworms).
Of particular risk to cattle and humans is the potential presence of eggs of the human tapeworm Taenia saginata. If cattle are exposed to untreated sewage or wastewater, these eggs can develop into the parasitic cysts (Cysticercus bovis) of “beef measles”. Consumption of contaminated, poorly cooked meat by humans would then result in the tapeworm infestation and an established cycle of infection. In addition to the ramifications to human health, Australia’s export meat markets are vulnerable to adverse affects as a result of detection of this parasite in beef.
If the sewage contains industrial wastewater such as from abattoirs or livestock saleyards, there is a high likelihood of contamination with Mycobacterium paratuberculosis, the cause of Johne’s disease.
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 Victoria’s 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.
Also, it should be determined whether the reclaimed water included input of abattoir or saleyard waste, as treatment is unlikely to completely remove the risk of Johne’s disease if young cattle are subsequently exposed.
Opportunities for use of reclaimed water in cattle production
Reclaimed water for use by cattle must have received effective helminth removal at the treatment plant, with water also having a minimum of secondary treatment and disinfection.
[Note: If reclaimed water that has not had a prescribed helminth treatment is applied to land, approval must be obtained from the Chief Veterinary Officer of DPI prior to the land being grazed by cattle. Such land would generally need to be spelled for a lengthy period (including a summer) or cultivated and re-sown to pasture.]
Class A water (including helminth treatment)
May be used without restriction in cattle production.
Class B water (including helminth treatment)
May be safely used with observation of some brief wihholding periods. Refer Table 2.
Class C water (including helminth treatment)
May be safely used with observation of some brief wihholding periods. Refer Table 2.
Class D water
Not recommended for use in livestock production.
Further information
- Comprehensive guidance on agricultural use of reclaimed water may be found in two publications that can be downloaded from the EPA website
1. GEM – Use of Reclaimed Water (EPA Victoria, 2002 publication 464.1).
2. GEM – Disinfection of Treated Wastewater (EPA Victoria, 2002 publication 730).
Tables
|
Table 1. Treatment classes
|
(Modified from EPA, GEM: Use of reclaimed water, 2002)
|
|
Water Class |
E coli level
(orgs/100ml) |
Treatment Processes at the plant |
|
A |
<10 |
Tertiary and pathogen reduction with sufficient log reductions to achieve:
<10 E. coli per 100ml;
<1 helminth per litre;
< 1 protozoan per 50 litres; and < 1 virus per 50 litres. |
|
B |
<100 |
Secondary and pathogen reduction (including helminth reduction for cattle grazing use schemes) |
|
C |
<1,000 |
Secondary and pathogen reduction (including helminth reduction for cattle grazing use schemes) |
|
D |
<10,000 |
Secondary – no pathogen reduction | |
Table 2. Opportunities for usage
|
Recommended use of differing classes of reclaimed sewage water# in cattle production |
|
Type of water usage |
Class of water
(with helminth treatment) |
|
Class A |
Class B |
Class C |
|
Livestock drinking water |
|
|
x |
|
Dairy shed wash-down |
|
1 |
x |
|
Pasture or fodder crop application
– lactating dairy cattle |
|
2 |
3 |
|
Pasture or fodder crop application
– non-lactating cattle |
|
|
2 |
|
Hay production for use on farm by cattle |
|
|
|
|
Pasture ensilage-
Use on farm by cattle |
|
|
4 |
|
Sale of fodder or crops |
5 |
5 |
5 | |
|
use is recommended (subject to comments, if any, below)
x not to be used for this purpose
1 but not for milking machinery
2 restrict access for 4 hours or until pasture/fodder crop is dry |
3 restrict access to lactating cattle for 5 days after application
4 wait for 4 hours or until dry before ensiling
5 product to be labelled or sold with instruction ‘fodder not for consumption by pigs’ |
# NOTE: If the reclaimed water includes inputs from saleyard or abattoir waste, additional measures to these should be undertaken to ensure that young cattle (under 12 months of age) are not exposed to the reclaimed water to minimise the risk of infection with Johne’s disease.
Acknowledgements
This Agnote was developed by Andrew Cameron, February 2003.
It was reviewed by Andrew Cameron Biosecurity Victoria, May 2009.
