The Dairy Effluent WoF is a 3-4 hour assessment which covers effluent consents and permitted rules, the storage capacity, nutrient loadings, soil risk, irrigator performance, off-pasture infrastructure and general health and safety requirements. A typical assessment consists of:
After the assessment is complete a comprehensive report is provided to the farmer with areas of concern, why and suggested actions.
The risk assessment framework has been developed from an AgResearch risk assessment study, modelling different effluent infrastructure and on-farm management scenarios. This estimates the environment impact of various defects in systems and assigned scores and weighting to the risk assessment.
As part of the WOF assessment any bridges and culverts on farm are assessed to see if there is any overland flow off them to the waterway. They are also assessed on the frequency that they are used on farm as infrequent use lowers their risk and the risk of effluent reaching waterways.
The assessor will also look at the storage facilities integrity to see if there are any issues that could arise. This involves assessing the banks and construction to see if there is any slumping or holes in the banks of the facility.
When the WOF is carried out by the certified assessor they will look at any farm drains to see if there is any risk of effluent reaching the drain from applications or infrastructure.
This component looks at any feed pad on farm and whether is appropriately lined, sealed, and contained. It also assesses if there is any risk of effluent reaching a waterway.
This component looks at any housed facility on farm and whether is appropriately lined, sealed, and contained. It also assesses if there is any risk of effluent reaching a waterway.
As part of the WOF assessment any tracks and races are assessed to see if there is any overland flow present. This is assessed to see if there is a risk of effluent reaching waterways and if there are any mitigation practices in place.
The assessor will look at the pipes and hydrants of the effluent irrigation system to check for leaks or discharge and if that discharge could potentially reach a waterway.
In this component the assessor will look for signs of poor irrigation such as previous ponding or overland flow or signs the effluent may have previously reached a waterway.
The assessor will look at the pipes and hydrants of the effluent irrigation system to check for leaks or discharge and if that discharge could potentially reach a waterway.
If an irrigation depth rule is in place from the Regional Council, the WOF assessor will check if the irrigation depth applied meets the corresponding rule. They will also check the irrigation depth against the soil risk on farm to see if appropriate depths are being applied to avoid ponding or overland flow.
This component looks at the farms nutrient budget to see if the block that effluent is applied too is large enough to meet industry good practise of no more than 150kgN/ha/year.
The WOF assessor will look at any relevant resource consents from the regional council if required in the region. They will assess the farms consent conditions against the WOF assessment to ensure the farmer is not breaching any conditions.
The WOF assessor will observe if there are appropriate safety systems around the farms effluent storage such as fencing, ladders, and signage. This is not part of the risk assessment but should provide farmers with good practice.
This component looked at the containment of effluent on the cowshed’s concrete and if it can lead to ponding or discharge to water.
If solids are separated in the farm effluent system and assessor will look at the spreading of these solids to see if they are applied evenly, at an appropriate depth for the nutrient content of the solids, and that there is no risk of the solids reaching a waterway.
If there is solid separation on farm the assessor will assess if the solids are stored on a sealed, contained surface and if there is any discharge from the solids to water. The assessor will also base this risk on the size of the effluent solids present.
This component looks at any stand-off pad on farm and whether it's appropriately lined, sealed, and contained. It also assesses if there is any risk of effluent reaching a waterway.
This component assesses the removal of the stone trap solids and if it is stored on a suitable, sealed and contained surface before it is spread on the farm. This also looks at the risk if this reaching waterways.
As part of the WOF assessment a storage calculation will be completed to assess if the farm has enough storage according to the ‘Dairy Effluent Storage Calculator’. This component looks at the amount of storage on farm and if it is adequate for the farm system.
This component assesses the likelihood that the storage facility is sealed to a standard that prevents any leakage to groundwater. This assessment is based on the information provided to the WOF assessor and their own knowledge and experience.
This looks at the containment of effluent in the cowshed sump, if it is sealed and if the sump has overflowed in the past.
This component looks at the discharge from underpasses and if it is applied to land appropriately or if there is risk that the discharge could reach a waterway. They are also assessed on the frequency that they are used on farm as infrequent use lowers their risk and the risk of effluent reaching waterways.
The Dairy Effluent Storage Calculator is a software tool which looks at a farm’s inputs of soil risk in the effluent block, catchment areas, feedpads or barns and their use; wash water in the dairy, effluent irrigation depths, and the daily volume of effluent able to be irrigated.
The Dairy Effluent Storage Calculator hold 30 plus years of local rainfall and evapotranspiration data, and from there it calculates a daily soil water balance to determine how often effluent irrigation could occur, or if conditions are unsuitable how much effluent should be directed to storage.
Graphs show maximum storage volume required for each season over the last 30 years.
The storage calculator is great for checking existing pond volumes if there is a pond already on farm, or determining pond volumes for new systems, and for running scenarios to compare the different inputs to find out where the farmer gets the best value.
The WOF report is delivered following the 3-4 hour assessment.
The WOF report shows detail from each of the Risk Assessment Standards, application rate graphs, and other statistical information about the farm’s effluent systems.
The WOF report helps you understand all the requirements to make sure your system is fit for purpose and capable of being compliant 365 days a year, or can be used by 3rd parties such as banks, valuers, purchasers, or shareholders.
AREA OF RISK |
WHY OF CONCERN |
SUGGESTED ACTION |
---|---|---|
High Application depth |
Average depth applied greater than allowed in WRC rules |
Repair and maintain irrigation |
Siphoning and ponding at first irrigator |
Ponding can occur breaching WRC rules |
Ensure irrigator is moving after pump turned on. Repair. |
Sludge piles on unsealed surface |
Leakage from the pile appeared to be going to drain, breaching WRC rules. |
Place stone trap cleaning on a sealed surface that drains to the effluent system |
Pump quite noisy |
If it is not working well, irrigator performance may decrease. Risk of catastrophic failure & damage to pump and motor. |
Have pump serviced or checked out |
Camlocks fitted to drag hose in incorrect direction |
The Camlock legs get damaged when line is moved, also they could catch and uncouple the hose while irrigating. |
Re-fit the correct way so that the "legs" are not being pulled. |
What’s the point of getting a Certified ‘WOF’ Assessor out on my farm?
How is the ‘WOF’ different from the regional council or Fonterra shed inspection?
What kind of information do I get for my money?
What training have Certified 'WOF' Assessors had?
Do regional councils have access to the information collected?