Rex Corlett, WSP's technical principal for rural infrastructure, was the lead consultant involved in drafting the Code.
Dairy effluent ponds are storage systems on dairy farms that hold animal waste before it can be safely applied to land as a nutrient-rich fertilizer.
There are about six million cattle in the country's dairy herd. That's a lot of animals excreting a lot of waste. Up and down Aotearoa New Zealand, there are more than ten thousand ponds to capture effluent from dairy sheds and stockholding areas.
Ponds can seep or leak if not properly designed and looked after. One way to understand if this is happening is via a 'pond drop test'. Here, high precision equipment is used to measure changes in pond level.
Commissioned by industry organisation DairyNZ, the updated Code sets out a standard methodology for the pond drop test. It introduces simple tools that farmers can use as early-risk indicators to detect significant changes in pond levels, which are a big red flag for leaks, and introduces a process for issuing farmers with a test certificate.
DairyNZ is now inviting regional councils to adopt the Code and have farmers follow its best practice guidance as part of effluent pond resource consents.
The new Code reflects advances in technology and introduces several new requirements to lift the overall standard of testing. This will mean greater certainty for farmers around what they need to do for their effluent ponds to meet consent conditions, and for local councils about the quality and reliability of effluent pond testing.
Rex says it's pleasing to have the new Code published and available.
“It's something that's been long overdue. Previously, regional councils had no guidance around what constituted reasonable measurement of effluent ponds. Each was doing their own thing and there was no standard industry test.”
Tightening up testing standards is also set to be a big step forward in protecting the environment, he says.
“If a pond leaks, its nitrogen and other chemical elements enter the groundwater which can affect the quality of drinking water. And if nitrates enter watercourses they'll have a negative impact on ecological systems.”
In developing the Code, Rex drew on WSP's fifteen years of effluent pond testing expertise, and consulted with other testing providers, Waikato Regional Council and Environment Canterbury.
To find out more and to read the new Code, visit the DairyNZ website.
