Can stock truck effluent be discharged to dairy farms?

Discharging Effluent from Stock Truck Holding Tanks to On-farm Systems

“Stock effluent is spilled from trucks onto roads causing health, safety and environmental consequences.  The public image of the dairy industry is also damaged by these spillages.”

One possible solution is for truck effluent holding tanks to be emptied on-farm at the destination point into suitable disposal or containment systems that meet local Council discharge rules. In practical terms this could mean discharging effluent into existing dairy effluent systems which is subsequently discharged to pasture or alternatively into purpose built holding tanks that may be subsequently emptied either by application to pasture or to some other area of land.

There is a potential for an increase in disease transmission to occur associated with the proposed practice of disposing of stock truck effluent on farms. It is essential that, should changes occur, dairy farmers and those providing farm animal health advice understand the nature and level of disease risk presented, and the mitigation steps required to manage the change.  A Hazard Identification and Risk Management Assessment has been prepared, addressing this proposal within a Southland regional context.

The report concludes that discharging effluent from stock trucks into the farm dairy system without additional risk mitigation steps has the potential to increase the incidence of diseases.  For farms undertaking a large amount of between-farm trading with little consideration given to their current status, the increased risk is considered to be small. For well-managed operations where major attention is applied to high-quality animal-health management, the risk of introduction of disease is considered likely to be  higher and the report recommends holding the truck discharge and application to non-grazing land to effectively mitigate the risks presented.

There are no regulations to prevent farmers receiving effluent from stock truck holding tanks.  However, receiving effluent from unknown or mixed sources significantly raises the risk of introducing a disease into any herd.  To assist farmers, a Cow Transport Checklist has been prepared that explains the conditions for receiving effluent with stock.