Separated urine is the single richest source of recoverable nutrients in domestic wastewater – but in conventional septic and sewage systems, it’s the largest source of pollution. Herr Ltd designs front-of-pipe urine treatment systems that recover phosphorus and nitrogen as safe, pharmaceutical-free fertiliser, while protecting Irish rivers and groundwater from the algal blooms, antibiotic residues, and nutrient runoff that conventional systems struggle to remove.
Our systems are designed for self-builders, eco-homes, and rural homeowners across Ireland who want to address pollution at the source and recover a valuable resource in the process.
Why Treat Urine at the Source?
- Tackles Ireland’s biggest water pollution problem – Most nitrogen and phosphorus in surface waters originates from human and cattle urine. The World Economic Forum has identified nitrogen and phosphorus as having exceeded planetary boundaries.
- Prevents algal blooms – Lough Derg and many other Irish lakes suffer summer blooms that harm fish, irritate children, and pose risks to dogs.
- Removes pharmaceuticals at source – Around 64% of ingested pharmaceuticals are excreted in urine. Treating urine separately is far more effective than end-of-pipe removal.
- Tackles antibiotic resistance – The UN warns that wastewater-borne antibiotic resistance could kill 10 million people a year by 2050. Front-of-pipe treatment helps break this chain.
- Recovers a finite resource – Global phosphate rock reserves are depleting and prices are rising. Recovered struvite is a clean, slow-release replacement.
- Supports food security – Half the global population depends on synthetic fertiliser to grow food. As natural gas reserves used to make nitrogen fertiliser diminish, recovery from urine becomes essential.
The Herr Phosphorus Recycling System
Our flagship system is the Herr Phosphorus Recycling Reactor — a domestic-scale unit that recovers up to 90% of the phosphorus in separated urine as struvite (magnesium ammonium phosphate), a pure, slow-release crystalline fertiliser free from toxic metals or pharmaceuticals.
How It Works
- Step 1 — Separation — Urine is collected separately at source using urine-separating or waterless toilets (see our composting toilets).
- Step 2 — Struvite production — Magnesium salt is added to the collected urine. The salt and urine chemically react to form struvite crystals, which settle in the conical base of the reactor.
- Step 3 — Harvesting — The white struvite sludge is drained and dried over several weeks, producing a phosphorus-rich fertiliser.
- Step 4 — Use — The dried struvite is safe for use on food crops in the garden or on the farm.
The reactor requires no electricity, no chemicals beyond magnesium salt, and minimal maintenance. Learn more about the Phosphorus Recycling Reactor
Optional Follow-On Treatment
For homeowners wanting near-zero discharge, the urine that has passed through the struvite reactor can be polished further:
- Activated carbon filtration — Granulated activated carbon (GAC) filters remove residual pharmaceutical micropollutants. Filters should be replaced every 4–6 months.
- Hydroponic flower growing — A glasshouse-based vertical flower wall absorbs remaining nitrogen, potassium, and trace pharmaceuticals. Flowers grow odourlessly in diluted urine and require occasional rainwater top-up.
- Composting — Fallen leaves from the flower system are composted with toilet solids and food waste, completing the nutrient loop.
The hydroponic system is ideal for keen gardeners and eco-enthusiasts. It’s typically scaled for two-person households given the glazed space required.
Pricing
- 60-litre Struvite Reactor — supplied with magnesium salt and operational manual: €3,200 + VAT
- 80-plant Hydroponic Flower Growing System — with growing bed for comfrey: €6,200 + VAT
Using Recovered Fertiliser on the Farm or Garden
For farmers and smallholders, separated urine itself is a valuable fertiliser before any treatment:
- Direct application to grass and crops returns nitrogen and phosphorus to the soil.
- Recovered struvite can be applied to vegetable beds and fruit trees as a slow-release fertiliser.
- Cut leaves from comfrey beds (grown on diluted urine) make excellent mulch and compost activator.
- Replaces synthetic fertilisers, which are increasingly costly and tied to volatile gas markets.
Why It Matters for Ireland
- Septic tanks waste nutrients — Nitrogen and phosphorus end up in groundwater, contributing to surface water pollution.
- Climate-driven topsoil loss — As soil erodes into rivers, recovering nutrients at home becomes more important than ever.
- EU and Irish policy is moving slowly — The new struvite recovery plant at Ringsend (Dublin) recovers phosphorus but does not currently produce farm-grade fertiliser. Domestic systems can fill the gap today.
- Water charges and food prices — Recycling at home reduces reliance on both mains water and imported fertiliser.
Why Choose Herr Ltd?
- Over 30 years of experience designing ecological wastewater systems for Irish conditions.
- Specialist focus — One of very few Irish suppliers offering phosphorus recovery for single houses.
- Full design support — Consultation, system design, supply, and compliance documentation.
- Pairs seamlessly with our composting toilets, reed beds, and rainwater harvesting systems.
Ready to take pollution out of your wastewater and recover the nutrients hidden within it? Get in touch for a tailored consultation.
