Cleaner food production requires more than removing contaminants from a finished product. Water reuse, nutrient recovery and antimicrobial resistance show why prevention must follow materials across the wider environment.
A food factory can reduce the amount of water it draws while leaving a harder question unanswered: what happens to the substances carried by the water it reuses or discharges? A treatment process may capture a contaminant in a residue without destroying it. A nutrient recovered from one waste stream may become pollution if it reaches another place at the wrong concentration.
These connections make zero-pollution food systems an engineering and coordination challenge. Progress depends on preventing avoidable releases, understanding where remaining contaminants travel and checking that a resource-saving measure does not transfer an environmental burden. The relevant boundary extends from farms and processors to rivers, treatment works and the land receiving recovered materials.
Water quality exposes the limits of separate solutions
The European Environment Agency’s 2024 assessment describes widespread pressure on European waters from pollution, habitat degradation, water use and climate change. Based on Member State reporting for 2015–2021, only 37% of surface water bodies achieved good or high ecological status. The assessment identifies agriculture as the most significant pressure affecting surface water and groundwater, while also recognising pollution from other sectors.
That finding does not assign responsibility for every polluted river to an individual farm or factory. It does demonstrate why a food company’s own discharge figures provide only part of the picture. Its incoming water, suppliers and neighbouring land uses may share the same catchment, where the combined pressures matter.
A practical research partnership could therefore connect production data with catchment monitoring. It would need consistent sampling locations, flow information and an account of seasonal conditions. Without those details, a lower measured concentration could reflect dilution rather than a smaller release, while a higher concentration during drought could obscure improvements in the total amount discharged.
Recovering nutrients without recreating pollution
Nitrogen helps crops grow, but excess nutrients can damage waters and ecosystems. The EU’s Nitrates Directive addresses water pollution from agricultural sources, making nutrient management part of the legal foundation for protecting water. Recovering nutrients is therefore only one stage of a successful circular system; their subsequent use also matters.
For a processor or farmer considering a recovered fertilising material, the important information includes its nutrient composition, consistency and suitability for the intended application. The relevant comparison is not simply whether the material replaces a purchased input. It is whether the whole arrangement reduces losses while meeting crop needs and the applicable conditions for use.
This creates opportunities for research connecting recovery technology with agronomy. A trial could follow the nutrient from the original stream through treatment, storage and application, accounting for material that leaves the useful product. The results would help distinguish genuine recovery from a process that merely concentrates a problem and passes responsibility to another operator.
Water reuse needs a risk plan as well as a pipe
The EU Water Reuse Regulation establishes minimum requirements for using treated urban wastewater in agricultural irrigation. Its framework includes water quality, monitoring, permits and risk management. It does not provide a blanket authorisation to use any recovered water for any food-related purpose. The intended crop, exposure routes and local conditions remain important.
For an irrigation scheme, a useful innovation may be an arrangement that makes responsibilities clearer between the treatment operator, distributor and grower. The water can move through several organisations before reaching a crop. Each needs to understand which measurements it receives, what operating conditions those measurements represent and how a failure will be communicated.
Research should examine the whole operating cycle, including interruptions, maintenance and periods when water demand is unusually high. A demonstration under stable conditions offers limited reassurance about a scheme’s behaviour during a treatment failure. Evidence about response times and fallback arrangements can be as valuable as a high removal rate measured during normal operation.
Antimicrobial resistance crosses environmental boundaries
The issue becomes more complex when the concern is antimicrobial resistance. EFSA’s 2021 assessment identified water, irrigation and fertilisers of faecal origin as important sources of resistant bacteria or resistance genes for plant production and aquaculture. However, the available data did not allow the contribution of each environmental source to be quantified. That limitation remains essential when interpreting the assessment.
Detecting a resistance gene in a sample is not the same as demonstrating that a person acquired a resistant infection through that route. Nor is the presence of an antimicrobial residue interchangeable with the presence of a resistant organism. These measurements can inform different parts of the problem, but they need to be interpreted together with evidence about exposure and transmission.
UNEP’s environmental assessment places AMR within a wider network involving agriculture, pharmaceutical production, healthcare and waste management. Its central implication is that action confined to one sector cannot address all routes through which resistance develops and spreads. Food production is part of that network, rather than an isolated cause or an isolated solution.
For innovators, this argues for clear objectives. A treatment designed to reduce viable bacteria should report that outcome directly. A method designed to reduce particular residues needs a different performance assessment. Combining everything into a single claim of removing antimicrobial resistance would hide the distinctions needed to judge whether an intervention is useful.
Treatment can shift a burden rather than remove it
The revised Urban Wastewater Treatment Directive, in force since January 2025, extends the EU’s approach to pollution control, including additional treatment for micropollutants under a phased framework. Its existence reflects the importance of wastewater beyond any individual food business. Food processors operate within water systems receiving many types of discharge.
A technology assessment should therefore describe the fate of what it captures. If a contaminant moves from water into a filter medium or sludge, the treatment has changed its location. Whether that is an improvement depends on the management of the resulting material and on the environmental impacts of the process itself.
For a proposed installation, developers could report incoming and outgoing pollutant quantities alongside energy use, replacement materials and residual waste. These measures would make comparisons more useful than a headline percentage alone. They also help operators identify whether prevention at source could reduce the amount of treatment required, rather than continually expanding the capacity to handle avoidable contamination.
Measure combinations and decisions not just individual substances
Chemical assessment also needs to consider when substances share relevant effects. EFSA has developed approaches for cumulative assessment of pesticide residues, grouping substances according to common toxicological effects. This is a specific scientific method, not a justification for assuming that every detectable mixture is dangerous or that individual results describe every combined effect.
For the food sector, the broader lesson is to match monitoring to the decision being made. A water-saving project, a fertiliser-recovery plant and an antimicrobial-control intervention need different measures. All should explain their boundaries, identify important uncertainties and show who takes responsibility for material leaving the process. Reporting seasonal variations and the conditions under which performance deteriorates would make those assessments more useful to prospective operators.
A useful next generation of projects would build those responsibilities into their design. Farmers, processors, water companies and researchers could agree what information must follow a recovered material, then test whether the receiving organisation can use it. That would make the evidence relevant to a purchase, permit or operating decision, rather than leaving it in a final technical report.
Zero pollution is a demanding direction of travel. Its practical value lies in asking whether a food system prevents releases and reduces exposure across connected environments. Counting water saved or material recovered remains useful, but those achievements become more convincing when the fate of unwanted substances is visible too.
