The 6 reasons for installing waterless urinals in new houses in Ireland

We need to begin the prevention of pharmaceutical and phosphorus pollution in rivers, and to recycle phosphorus from urine.

Ireland is still struggling to adequately prevent nutrient and pharmaceutical pollution in our rivers and lakes. The EPA publication –Water Quality in 2023, An Indicators Report:  shows that improvements in the quality of our surface waters are not happening fast enough.

At the same time there is a growing number of scientists with the view that mankind cannot continue to put all domestic wastewater into one single pipe for later treatment. In agreeing with them I am proposing measures to implement a “paradigm shift” in the way we treat wastewater.

In the past solid household rubbish/waste always went into one single garbage bin. Today however, we continue to increase the separation of tins, plastic, glass, paper and kitchen food waste. We separate these various wastes because we know they will be better managed and recycled if they are kept apart. I want to argue therefore, that we do likewise with wastewater. Herr Ltd supplies toilets to separate and collect urine in the local area. The urine can be more effectively treated to remove and recover nitrogen and phosphorus, with a higher degree of purity than from municipal wastewater. Mankind can also more effectively remove pharmaceuticals and antibiotics from our surface waters by the separation of urine.     

Reason 1 – We need to prevent phosphorus in the urine from entering our surface waters

The most effective way to prevent phosphorus pollution in lakes, is at its true source, at the start and front of the pipe. I believe we should begin to install urine separation toilets and plastic storage tanks for the collection and later treatment of the urine. In implementing this paradigm shift, Herr Ltd is suggesting that pilot-demonstration-projects be implemented at community scale for new houses in villages or small towns. For Ireland to begin making significant progress at preventing and avoiding phosphorus pollution in lakes and estuaries, we must progress beyond the work in German & Swiss universities, where the technology to remove phosphorus from urine has been proven. . I propose that we scale up and apply this proven technology in large buildings, or in new housing developments of about 200.

At a domestic house scale, Herr Ltd is possibly the first in Ireland to successfully be removing phosphorus from the urine. The process being used is to mix urine and magnesium rich salt together, and then to filter the resulting sludge for drying. The process is not hazardous. The system which yields a by-product called Struvite, is a phosphorus rich fertiliser that can be used on farms or community gardens. The funding for this system was provided by Zero Waste Alliance Ireland and the Irish Environmental Network. Laboratory tests were subsequently carried out to measure the rate of the phosphorus removal after struvite has been produced. The original levels and the removal rates of the phosphorus from two urine samples were measured as follows:

Removal of Phosphorus from urineBefore adding magnesium to the raw urineAfter magnesium has been added – Producing struviteParameter: Measured by Oldcastle Labs
Sample 1286 mg/l 26mg/l   91% lowerTotal Phosphorus
137 mg/l5 mg/l     94% lowerOrtho Phosphorus
Sample 2198 mg/l9 mg/l    95% lowerTotal Phosphorus
155mg/l1 mg/l    99% lowerOrtho Phosphorus

Shown above is the Herr Ltd domestic phosphorus removal & recovery system, from separated human urine. In the table below, the urine fraction is the largest domestic source of nitrogen, phosphorus and pharmaceutical pollution that ends up in our groundwater and rivers.

Analysis of various pollutants in domestic wastewaterGrey WaterKitchen SolidsFaecesUrineFaeces & Urine together
Ref: Academic studies 
NB. These are only approximate figures
Nitrogen N7%8%15%70%85%
Phosphorous P12%14%26%50%76%
Potassium K10%15%25%50%75%
Faecal bacteria & faecal viruses100%100%
Excreted medicines & hormones30%70%100%

Using the Herr Ltd phosphorus treatment system, the removal rate of phosphorus from urine is very efficient, but the quantity that can be removed from a single house is small.

In contrast, 14 tonnes of phosphorus per day, as struvite, is being removed at the Ringsend sewage treatment system in Dublin. This very large amount would have ended up in Dublin Bay, so well-done, Úisce Éireann. For this reason, I believe that the Irish Government should be promoting this struvite production method of phosphorus removal in other large Irish cities.

Reason 2. Mankind needs to recycle phosphorus to agriculture, but this resource can also be recovered without toxins from separated urine   

Struvite is the byproduct when phosphorus is removed and recovered at Ringsend Sewage treatment works. This form of nutrient production from wastewater has less toxic metals, than from treated sewage sludge. The Irish Government needs to implement the same struvite production method in other large cities and urban areas in Ireland, but there has been no announcement of plans by Uisce Éireann at present, to do so.

It is widely believed that it is not viable to produce struvite from wastewater at small sewage works, in towns, villages, or from the domestic septic tanks. The Irish EPA have been reporting on the nutrient emissions from Irish septic tanks, and the capacity issues with overloaded town and village sewage treatment systems. Herr Ltd however has proven that phosphorus recovery can be done at single houses by enthusiastic homeowners. I am suggesting that that this urine treatment method be installed for new village housing clusters in small towns and townlands to remove and to recycle the phosphorus. Initially this would be a feasible community River Basin Management Plan project, for a Tidy Towns’ group. Please watch the video on how communities in Nepal recover phosphorus from separated urine.

Urine contributes about 50% of the phosphorus and about 70% of the pharmaceutical pollution from domestic wastewater. Urine also contains about 70% of the nitrogen which can also be a source of ammonia. Urine therefore has by far the greatest impact on river pollution around the world. Irish State organizations are failing to appreciate that urine is the major source of pollution. The Irish EPA are failing to regard urine as a significant and sustainable resource for phosphorus and nitrogen. The test results by Herr Ltd below, confirm the “almost undetectable” levels of “toxic metals” in the struvite fertiliser, that can be produced from urine:  

Struvite, from urine.Metals in StruviteMetals in StruviteUD – Almost Undetectable Toxic if ingested ingested in human body
Testing by Eurofins LabsSample 1Sample 2
Arsenic<0.8 mg /kg  dw<0.8 mg /kg  dwUDToxic
Lead<2  mg/kg  dw<2  mg/kg  dwUDToxic
Copper2  mg/kg  dw2  mg/kg  dw 
Nickle<1 mg/kg  dw<1 mg/kg  dwUDToxic
Mercury<0.07 mg/kg  dw<0.07 mg/kg  dwUDToxic
Cobolt<1 mg /kg dw<1 mg /kg dwUDToxic
Zinc32  mg/kg dw21 mg/kg  dw
Iron108 mg/kg dw149 mg / kg  dw
Cadmium< 0.2  mg/kg dw< 0.2  mg/kg  dwUDToxic

Copper, zinc, and iron levels were measured in the results, but this is only to be expected, since they are important trace elements for healthy human metabolism. Like the phosphorus, they are naturally absorbed in food and excreted in the urine.

From the results listed above, these figures for the toxic metals confirm with similar reports by academics that these metals in the struvite derived from urine are so small, that this fertiliser is almost pure. The reason for this is that the food we eat contains almost no worrying levels of toxic metals, so it follows that we will also excrete so little in the urine.  

Reason 3. Cadmium in imported commercial mineral-based phosphorus is a toxin and must be reduced and be kept out of the human food chain.

The European Union is currently concerned about cadmium levels that are present in soils, as well as from the cadmium in mineral based phosphorus fertiliser supplied from Morocco. The current target of this toxic metal in phosphorus being imported into Europe is to be 60 mg/kg dry weight.  At present the Moroccan phosphorus resource is the largest in the world but it has the greatest contamination of cadmium.

In a study “Cadmium in topsoils of the European Union – An analysis based on LUCAS topsoil database”

It is claimed that the mean cadmium content of fertilisers in EU is 36 mg/kg, but the level of cadmium can sometimes be as high as 200 mg/kg.

Toxic Cadmium levels in rock & in UrinePhosphorus available  from wastewater and from mining.Comments on the current supply status & and the scale of the Phosphorus supplyCategory of P Supply
Cd ? No info NorwayPotentially may have the biggest resource in the futureFinite
> 50 mg Cd/kg PMorocco & W SaharaCurrently by far, the largest active reserve in the worldFinite
10 -50 mg Cd/kg PChinaTrying to keep this large reserve for their own populationFinite
10 -50 mg Cd/kg PSouth AfricaA medium scale reserve, but will eventually be depletedFinite
10 -50 mg Cd/kg PSyria & JordanA medium size reserve, but will eventually be depleted Finite
> 50 mg Cd/kg PUSAA large reserve of their own but now also must importFinite
> 50 mg Cd/kg POther CountriesCountries with small reserves that will soon be depletedFinite
< 10 mg Cd/kg PRussiaLow toxic metal reserve – but their future supply is limitedFinite
< 10 mg Cd/kg PBrazilLow cadmium reserve – but their supply is limitedFinite
Cd & metals? From wastewaterAs Struvite with less toxins & metals than sludgeRecyclable 
< 0.2 mg Cd / kgStruvite from urinePurest local community supply, undetectable metals Recyclable 

This is an increasingly worrying public health concern for people in Europe. Toxic cadmium that is present in phosphorus fertilisers can be slowly taken up into food crops to accumulate over decades in humans. The European Union are at present negotiating with the member states to agree to targets to further reduce these levels to be lower than 20 mg/kg (dry weight). The cadmium level of < 0.2 mg/kg in phosphorus recovered as struvite from urine is 100 times lower again. It follows therefore, that we will most reliably prevent cadmium from building up in our topsoil by using systems as Herr Ltd does, to produce struvite from urine.

Reason 4. Pharmaceuticals will not accumulate or be collected in the recovered Struvite produced from separated urine.

As the urine is washed through the filter, to remove the phosphorus, almost none of the pharmaceuticals will remain in the recovered struvite. Less than 2% of the pharmaceuticals and organic pollutants will accumulate in the captured phosphorus. Unlike sewage sludge, the urine derived struvite fertiliser, can be used to fertilise food crops, with no worrying levels of pharmaceuticals. 

Reason 5. The pharmaceuticals present in excreted urine are ending up in our rivers.

Pharmaceuticals from excreted urine, pass through septic tanks and will also remain after the treatment process in municipal sewage treatment works. There is now, an ever-growing concern by scientists about the increasing levels of pharmaceutical pollution in rivers around the world.

Nearer to home harmful levels of antibiotics have been found in four Irish rivers. From 2020 to 2022, Scientists from Dublin City University, took surface water samples from the rivers Nore, Suir, Annalee in Co Cavan, and the Liffey in Dublin. They tested for 16 pharmaceuticals commonly proscribed for patients and found all of them present in the rivers.

The antibiotics that remain in treated and untreated wastewater discharges are contributing to increase and worrying levels of antibiotic resistance around the world. The proposed new European Union Urban Wastewater Treatment Directive will require member states to properly remove organic micropollutants, especially pharmaceuticals, but I worry that Member States will not begin to implement this measure in all treatment plants, soon, because of the high cost involved.

The World Health Organization is predicting 10 million premature deaths a year because so many anti biotic medicines are no longer effective. The WHO statement reads: “Currently, at least 700,000 people die each year due to drug-resistant diseases, including 230,000 people who die from multidrug-resistant tuberculosis. More and more common diseases, including respiratory tract infections, sexually transmitted infections, and urinary tract infections, are untreatable; lifesaving medical procedures are becoming much riskier, ….” 

The evidence is growing that the removal of these pharmaceuticals will be more economically achieved from wastewater by separating human urine and passing it through biochar. Urine is a tiny part of the total discharge volume, but accounts for 70% approx. of the excreted pharmaceuticals. The quantities of biochar required for this removal process will be 100 times less from human urine than from municipal wastewater. Google: “Separate waste-water treatment of urine could have lower environmental impact than centralised, combined waste-water treatment

Reason 6. Before we eventually close down fossil fuel power stations to avoid runaway climate change, we must prepare a plan to deal with a future of phosphorus shortages and unaffordable phosphorus fertiliser costs.    

There is a growing urgency to reduce global greenhouse gas emissions from coal, gas and oil to zero. It is not generally known that nitrogen and phosphorus in the bagged fertilisers that farmers buy to grow food crops, are both produced from fossil fuels. Mankind uses natural gas and coal to produce about 50% of the nitrogen fertilisers used to grow food globally. If in an effort to reduce climate change, we began to shut fossil fuel power stations then the availability of this nitrogen fertiliser supply would be greatly restricted. Mankind would experience a widescale food security crisis. Google: Nourishing the World: Natural Gas as a Cornerstone of Global Food Security. 27 March 2024 Doha

Furthermore, when natural gas is being burned to produce the nitrogen fertiliser, sulphur along with carbon dioxide is emitted to the atmosphere. To prevent “acid rain” being emitted from fossil fuel power stations, the sulphur contained in the flue gas must be filtered and scrubbed. In doing so, sulphuric acid is produced as a by-product which has become one of the most important industrial chemicals that is needed for the modern world. Along with the mining of so many more metals and minerals for the green economy, this acid will also be required to extract and process phosphorus from crushed phosphate rock. Depending on which experts you read, some 50% or more of the current global supply of sulphuric acid is used to produce phosphorus fertiliser comes from flue gas scrubbing. As the global green economy grows and more of these metals & minerals are extracted, then the demand for sulphuric acid will also increase and grow. The concern is that with higher demand, for rare earth metals, mankind will experience significant supply shortages. The higher global prices and shortages of sulphuric acid will also arise with the ever-growing demand of phosphorus fertiliser. Farmers in the 3rd world will be struggling because of unaffordable phosphorus prices.   

To reduce the global dependency and demand for sulphuric acid, scientists recommend alternative sources of phosphorus, such as the recovery and recycling of phosphorus from wastewater. Struvite recovery on a large scale is only viable from large urban centres such as Dublin, and time might be running out. I believe there will still be a global shortfall. As well as promoting the bioeconomy, I believe Ireland must urgently also recycle phosphorus by collecting and treating urine in the smaller towns and villages and at community scale.


Mankind may not adequately achieve Net Zero Emissions in time to prevent the worst of climate change. I am concerned that the climate change that we already have will become increasingly chaotic and destructive and will increasingly impact on the dependability and the economics of farming. The Government might be too late in recycling phosphorus with minimal toxic metals to the food chain from wastewater and from urine. I also believe that our current generation is still not adequately aware of the need to take action to prevent pharmaceutical pollution and reduce antibiotic resistance.  All of these factors will threaten public health, our clean water supplies, and our global food security. I believe therefore that mankind must urgently begin to separately treat urine.