A Clean Green Effluent Company system at Sharon and Willie Muir’s 125-hectare dairy farm in Tīmurua is demonstrating how innovative technology can deliver both environmental benefits and operational simplicity for New Zealand’s dairy sector.
The Muirs, who milk 315 cows, have successfully implemented the fully patented Clean Green Effluent Company solution that eliminates the need for large storage ponds through advanced weeping wall technology and automated low-rate application.
“I’ve known Lindsay for 20 years and knew I could trust him to put in a very good system,” explains Willie. “I even put it in without going to look at one as I knew with Lindsay it would be a great system.”
The decision to install the Clean Green system was driven by practical considerations and a desire to reduce maintenance.
“We had a mechanical separator we’d had problems with in the past and it just wasn’t performing,” says Willie. “We wanted to get away from cleaning out stone traps and I knew a weeping wall would simplify our system and reduce labour and maintenance costs.”
The Clean Green Effluent System represents a significant advancement in dairy effluent management, featuring a unique patented concrete-lined weeping wall that removes 35% more solids and nutrients from effluent than any other tested weeping wall system. The system is over 1,000 times cleaner than a solids press.
The technology’s core innovation lies in its ability to separate liquids from solids within the patented timber weeping walls, capturing the bulk of NPK nutrients in organic humus while allowing controlled application of liquid effluent at extremely low rates — as little as 0.25mm per 24 hours.
“When I run my system, the water is a really light colour now compared with my previous system, so I can tell the Clean Green Effluent Company weeping wall separation system is doing a great job,” explains Willie.
The system achieves significant freshwater savings, with industry standards typically requiring 50–70 litres per cow per day for shed and yard washing, while farms operating Clean Green Effluent Company systems report average usage of just 15–20 litres per cow per day.
For Willie and Sharon, the automated nature of the system has also eliminated daily stress and operational complexity.
“It discharges the effluent daily, eliminating concerns about ponding or runoff. The technology has performed flawlessly, and on inspection it’s clear that Lindsay has designed the system with farmers in mind as it’s so straightforward and easy to use.”
The system’s monitoring requirements demonstrate its user-friendly design. The system uses two tanks with float indicators to show levels — “One tank should always be empty and the other full.”
“When I see one float up and the other down, I know everything is running exactly as it should. It’s that simple — no more last-minute stress or unexpected full ponds for us.”
The Muirs have already observed tangible improvements in pasture quality.
“I believe the cows are grazing the paddocks better because the grass quality is better,” says Willie. “The system’s low-rate, low-depth application ensures all nutrients remain in the root base, with nutrient leaching significantly reduced compared to traditional systems. I also anticipate long-term soil health improvements from putting a better-quality effluent product on.”