Over the last few years, we have seen a large shift in farmers upgrading their dairy effluent systems. Because of the large capital cost, many farmers are using their existing clay lined ponds. However, most of these ponds were constructed prior to the soil and compaction methods required if the same ponds were installed today. This doesn’t mean they are all leaking, but it does mean regional councils are asking questions about their fitness for purpose and compliance with their rules.
Therefore, farmers are being asked by regional councils and/or milk supply companies to provide some proof or assurance that their ponds are not leaking.
AgFirst has developed a methodology to undertake Pond Drop Tests (PDT) in the Waikato, Auckland, BOP & Taranaki regions.
What is a PDT?
- Cost-effective, non-evasive method to ensure that a pond liner is performing within the seepage/permeability expectations set by the local regulator authority.
- Provides evidence that the pond is compliant.
- Continuous short-term monitoring to identify any change in water/effluent level.
- Can undertake the test anytime during the year (milking or dry season).
- AgFirst have multiple testing kits, so can save time and $$ by testing both ponds at once.
Importance of a PDT?
- Councils are clamping down on non-compliant dairy farms.
- Part of a compliant farm is evidence to show the dairy effluent pond is performing to the set permeability standards.
- The cost to have a PDT undertaken versus the costs to construct a new pond.
- Part of farm purchase / lease / supervision due diligence.
Things to consider for a robust Pond Drop Test:
- Pond needs to be three quarters full
- Ideally settled – a week or more if filled from empty, as the pond walls can soak up liquid and result in a false loss
- Pond effluent level below any outlets, with enough working depth to not overflow during the test
- Minimal floating or suspended solids or crust as this can impact the test and foul up the probes
- Any additional ponds or waterways adjacent or a high-water table that may be seeping into your effluent pond can pose a risk
- Fallen trees or trees/large shrubs on the pond embankment
- Preferable to have enough storage available without having to irrigate during the test
- We can undertake the PDT during the milking season by removing the pond inflow events
Contact AgFirst Waikato to book your testing: waikato@agfirst.co.nz or +64 7 839 2683
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