Key questions about the industrial impact of the Royal Decree on Water Reuse

On January 30th, SITRA organized a webinar where we analyzed the industrial impact of the new Royal Decree on Water ReuseDuring the day, Manuel J. González, an agricultural and civil engineer and lecturer at the University of Seville, and Cristina Ferrer, head of the Operation and Maintenance area at SITRA, addressed points such as the situation of reuse in Spain, the incentives we can get from this regulation to commit to reuse at an industrial level, and even presented us with success stories related to this practice.

Hundreds of professionals from various sectors attended the event and asked questions about key issues in their industries. Therefore, in this post, we'll compile all those questions so you can find the answers you need. Let's get started!

Get information from our experts on how this Royal Decree affects your company

How should a company that already has a permit to reuse its own treated wastewater proceed? What are the deadlines for adapting?

According to Royal Decree 1085/2024, the deadline for new applications for production authorization and concession for use of reclaimed water is, for producers of reclaimed water for industrial use (everything that is not agricultural), until December 31, 2025 to apply for authorization.

If we talk about users, for non-agricultural uses, they must apply for the concession or adapt the existing authorization/concession before December 31, 2028, and it is important to keep in mind that these deadlines are limits to start the procedures for adapting to the new regulation:

• Production and Supply Authorization (APS): It is requested by the regenerating station operator (ERA) and focuses on the Regenerated Water Risk Management Plan (PGRAR).
• The competent authority has a maximum of 12 months to resolve the request, and the health authorities have a maximum of 3 months to issue their report.
• Reuse concession (CRA): It is requested by the user of the reclaimed water and focuses on hydrological planning and its compatibility with the objectives of said planning.
• The concession must be registered in Section A of the Water Registry. If the applicant for the concession is the same entity that operates the regeneration plant, both procedures (the concession and the production and supply authorization) can be processed simultaneously.

Furthermore, the new regulation establishes that the competent authorities must include and update annually in the census of authorized discharges, all information related to the authorizations for the production and supply of reclaimed water.

Which regeneration technologies do you think are best suited for industrial use?

For industrial applications with low requirements (such as refrigeration and non-critical processes), advanced biological treatment combined with sand filtration and chlorine disinfection is sufficient. This effectively eliminates bacteria and provides a cost-effective microbiological barrier.

In more demanding cases, such as the agri-food industry where there is indirect contact with products, a more robust combination is required:

• Ultrafiltration (UF) to remove fine solids and some microorganisms.
• Ultraviolet (UV) light for disinfection without generating by-products.
• Supplemented with ozone or hydrogen peroxide to reduce organic matter.

For the most demanding applications (pharmaceutical or electronics industries), where total elimination of pathogens is required, the following is implemented:

• Double-pass reverse osmosis
• Nanofiltration for virus and protozoan retention
• Advanced disinfection with ozone or high-intensity UV

To achieve the highest quality (A+) for industrial use, only ultrafiltration systems (with pore sizes of 0,04 and 0,1 μm) combined with UV treatment can guarantee the effective elimination of viruses and protozoa. For less demanding quality levels (C or D), traditional physicochemical treatments with basic disinfection may be sufficient.

It is important to keep in mind the concept of multiple barriers: lower quality water can be used if additional control barriers are implemented to ensure an equivalent level of risk. This allows for flexibility in technology selection while maintaining the required safety standards.

The key is to adapt the treatment train according to the specific end use, considering both the efficiency in pathogen removal and the economic viability of the process.

Some possible examples:

Industrial use	Required Quality	Key Technologies	Usage Example
Refrigeration, washing and non-critical processes	Low or medium (without direct contact with sensitive products)	Advanced biological treatment, Sand filtration, Chlorine or sodium hypochlorite, Chemical oxidation systems	Cooling towers, surface cleaning in industry
Agri-food industry (indirect contact with products)	High (no pathogens, low turbidity and good control of emerging contaminants)	Ultrafiltration (UF), Ultraviolet (UV) light, Ozone or hydrogen peroxide, Activated carbon granular (CAG)	Machinery washing in the agri-food industry, fermentation processes, use in steam boilers
Pharmaceutical and cosmetic industry	Very high (absence of microorganisms and chemical contaminants)	Double-pass reverse osmosis (RO), Nanofiltration, Disinfection with hydrogen peroxide or ozone, Adsorption with activated carbon	Production of cosmetics, pharmaceuticals, water for formulations
Paper and textile industry	Moderate (hardness and suspended solids control)	Advanced flocculation and coagulation, Membrane filtration (UF or NF), Electrodialysis reverse (EDI), Chlorine disinfection	Paper production, textile industry with dyeing processes
Electronics and semiconductor industry	Ultrapure (total removal of salts and microorganisms)	Reverse osmosis with polishing on ion exchange resins, Electrodeionization (EDI), Filtration through 0.01 micron membranes, High intensity UV	Semiconductor and printed circuit board manufacturing

 

 

Is the reuse regulation an opportunity or a challenge for the industrial sector? What challenges might companies face in implementing the use of reclaimed water?

The Water Reuse Regulation (Royal Decree 1085/2024) marks a turning point in industrial water management, and above all, it is important to highlight the inclusion of the food industry in the new regulation. The fundamental premise is that "The most expensive water is the water you don't have."This reality becomes especially evident when companies depend exclusively on conventional sources for their development and operation, or even for their expansion.

The use of this water source to enable industries is interesting. diversify your supply sourcesreducing dependence on conventional water and the risks associated with its availability. Very important for companies that plan to expand their operationsSince the availability of reclaimed water can facilitate growth without relying on new conventional water concessions, industries can secure a more stable supply and reduce their dependence on conventional sources by choosing reclaimed water.

Another interesting aspect, when it comes to improving the competitiveness of industries and which is reflected in the new regulation, is the introduction of Transparent Water Management Seal, a certification awarded by the State Secretariat for the Environment that recognizes companies committed to the efficient and transparent management of reclaimed water.

This badge can become a significant differential value for two main reasons: it can facilitate access to public tenders where sustainability is a value criterion, and can open doors to aid and funding programs aimed at promoting the circular economy.

From an economic point of view, regeneration can be especially attractive for industries that are currently They pay high fees for municipal water supplyAlthough the implementation of regeneration systems requires a considerable initial investment in infrastructure and technology, the operating costs can be amortized through the savings on conventional water rates and the reduction of landfill fees.

 

Which entity do you think will act as the Water Observatory?

It is highly likely that the Water Observatory will report to the Ministry for Ecological Transition and the Demographic Challenge (MITECO), specifically the Directorate General for Water, as they lead water management at the national level. There could also be coordination with the river basin authorities, which have more localized knowledge. Furthermore, with the impetus of the Water Strategic Plan (PERTE del Agua), digital tools have begun to be developed, and the company NTT DATA is already creating platforms to centralize information. However, the challenge is not only technical; it also lies in having enough qualified staff to manage and analyze all this information.

 

Regarding water quality for environmental use, turbidity has increased from 2 to 5 NTU in direct aquifer recharge. Previously, a turbidity level of 2 NTU required the use of reverse osmosis (RO). Why the increase?

The change from 2 to 5 NTU aims to make requirements more flexible and reduce implementation costs. Previously, with a 2 NTU limit, reverse osmosis, which is very expensive and energy-intensive, was almost mandatory. By allowing up to 5 NTU, other, more economical technologies, such as ultrafiltration, can be used without compromising safety. Furthermore, this decision aligns with a more practical and cost-effective approach, implementing additional safeguards to ensure quality rather than always requiring the most stringent treatments.

 

When does a recirculation cease to be a recirculation and become a regeneration, and therefore need to be authorized as such?

Royal Decree 1085/2024 excludes internal recirculations within industrial processes from its scope. That is to say, If the water is used and treated within the same process without leaving it, it is not considered reuse according to this royal decree and therefore does not require specific authorization under this regulation.

However, When treated water is used for a purpose other than the original process because it comes out of that recirculation, even within the same industrial facility, it is considered reuse of reclaimed water. In this case, it is necessary to comply with the requirements established in RD 1085/2024, which includes obtaining the corresponding authorization and ensuring that the reclaimed water meets the quality standards for its new use.

For example, in a food processing plant that processes lettuce, the water used to wash the lettuce can be filtered and recirculated for the same washing process without this being considered reuse under Royal Decree 1085/2024. However, if this treated water is subsequently used to clean the facilities or for processes other than washing lettuce, it is considered reuse of reclaimed water and is subject to the provisions of the Royal Decree. The key distinction lies in the use of the treated water: if it is recirculated within the same process, it is not considered reuse under Royal Decree 1085/2024 and does not require authorization. If the treated water is used for a process or purpose different from the original one, it is considered reuse of reclaimed water and must comply with the requirements and authorizations established in the Royal Decree.

 

Who is responsible for issuing the PGRAR? Depending on the uses, the risks may be different.

Article 21 of Royal Decree 1085/2024 establishes that the responsibility for preparing the Reclaimed Water Risk Management Plan (PGRAR) lies with the holder of the authorization for the production and supply of reclaimed water. This means that the entity that manages the Processing facilities and produces the regenerated water is responsible for its writing.

This could be a public administration, a private company, an industry, or an entity that owns a wastewater remediation plant. If several entities are involved in the production and supply, the regulations allow the Wastewater Treatment Plan (PGRAR) to be developed jointly with the other involved entities.

 

If the industry has its own wastewater treatment plant and treats the water at the outlet for reuse, is it considered reclaimed water and does it require authorization under the Royal Decree?

Article 2 of Royal Decree 1085/2024 defines reclaimed water as wastewater treated at a wastewater treatment plant and subjected to further treatment to meet the quality requirements necessary for its reuse in authorized applications. Therefore, if an industry has its own wastewater treatment plant, treats its wastewater, and then applies further treatment for reuse, it can be considered reclaimed water, and thus all the provisions of Royal Decree 1085/2024 apply. In this case, it is necessary to request authorization for production and supply, as well as a usage permit, since it is both the producer and the user.

 

After treating the liquid fraction of a digestate (waste) to obtain "treated water" suitable for irrigation, is it excluded from the RD?

When we talk about treating the liquid fraction of leachate, we are referring to purifying leachate that would normally be discharged into the Public Water Domain (DPH) or the Maritime-Terrestrial Public Domain (DPMT), or the sewer network, with the corresponding discharge permit. Therefore, if treatment is involved, then purification is also involved. According to Article 2 of the regulations, "reclaimed water" is defined as wastewater that has been adequately treated to meet the quality requirements necessary for its reuse in authorized applications.

Therefore, if the liquid fraction of a waste digestate has been treated to a quality suitable for irrigation, it would be considered "reclaimed water" according to this definition.

 

 

If the consumption of reclaimed water is internal within the industry, must the analytical controls described be followed?

If the water has already been reclaimed, analytical controls must be carried out, although Royal Decree 1085 states that the required level of control can be reduced, provided that the water quality is higher than that for its intended uses. For example, if the water is classified as A+ or A, but part of it is used for cleaning facilities, in this latter case, a request can be made to the competent authority to reduce the level of analytical controls.

This flexibility is subject to the approval of the competent authority and must be duly justified in the Reclaimed Water Risk Management PlanIt is essential to demonstrate that, even with a reduction in controls, health and environmental safety is guaranteed in the intended use.

According to Article 18.3 of the regulations, the holder of the production and supply authorization may submit a reasoned request to reduce the indicators or the frequency of analysis when the probability of the presence of certain parameters in the reclaimed water is low. This request must be evaluated and approved by the competent authority.

 

There is an obligation to reuse water in towns with more than 50.000 inhabitants, even without water scarcity. How can this end?

All urban areas with more than 50.000 inhabitants are required to justify why they do not reuse reclaimed water. Smaller municipalities must also submit simplified proposals. This will encourage reuse nationwide, but will depend heavily on the organizational and financial capacity of each municipality. In cities with public, private, or mixed water companies, the situations will vary considerably. Regional governments are likely to lead this effort, although much remains to be organized.

We may initially see minimal implementation, but over time, European demands will push everyone to adopt more ambitious solutions.

 

Can a user who receives reclaimed water of a certain quality subject it to treatments to achieve a higher quality and use it for a purpose other than that authorized?

Risk Management Plans are like workplace risk assessments, but applied to reclaimed water. They require advanced technical knowledge: understanding facilities, protective barriers, and contaminant dispersion is essential. Currently, there are few officials in river basin authorities who can oversee these plans, and most of the experts work in public health.

This raises the urgent need to train specialized environmental and water resource technicians to perform these functions. Undoubtedly, this is a challenge that will take time, but it is essential for the proper implementation of the regulations.

 

Is it possible to justify not removing nitrogen (N) and phosphorus (P) from reclaimed water intended for industrial processes, just as the new TARU allows in the case of its agricultural use for irrigation?

The new Urban Wastewater Treatment Directive (Directive (EU) 2024/3019) emphasizes pollution reduction and the control of nitrogen (N) and phosphorus (P) due to their impact on eutrophication. While it allows exceptions for N and P removal for agricultural use when the benefits are justified, it does not explicitly address this possibility in industrial processes.

The feasibility of the industrial use of regenerated water with N and P could be justified under three criteria: resource efficiency (when these nutrients add value to the industrial process), risk management (demonstrating absence of risks to health and the environment) and circular economy (in closed circuits or as an input in specific processes).

Its implementation would require a solid technical and scientific justification, along with the approval of the competent authorities. Although not currently covered by the directive, the industrial use of reclaimed water with N and P could be considered viable on a case-by-case basis., suggesting the need to develop specific policies in future regulatory reviews.