SONIA BALUK, XAVI GARCÍA SABÍN
The draft Royal Decree on the control of the quality of these waters establishes deadlines from July 2023.
The content of emerging contaminants such as PFASs, microplastics and antibiotics in drinking water is of serious concern, especially in large cities. PFASs have been used for years in the formulation of a wide range of commonly used products. It was only in the early 2000s that awareness of their impact on the environment was raised due to concerns about their potential harmful effects on human health. Control of their presence in drinking water and the establishment of parameters is of vital importance.
The draft Royal Decree establishing the technical and sanitary criteria for the supply and control of drinking water quality, of the Secretary of State for Health belonging to the General Directorate of Public Health of the Ministry of Health includes PFAS (per- and polyfluoroalkyl compounds) in its list of control of new parameters. The purpose of the proposal is to establish the permitted values of these and other contaminants, so as to guarantee the healthiness, quality and cleanliness of the water reaching the consumer, thus protecting people’s health, evaluating the associated risks at an early stage and informing the population in cases where their health could be endangered.
The document also aims to incorporate into Spanish domestic law Directive (EU) 2020/2184 of the European Parliament and of the Council of 16 December 2020 on the quality of water intended for human consumption.
PFAS values
The draft Royal Decree establishes in its annex the new parameters for these pollutants and their compliance schedule. In the case of PFASs, different dates are established depending on the parameters to be controlled. Thus, for the sum of 4 (Σ4) PFAS (specified in the annex of the decree), operators must control them before July 1, 2023 and drinking water must comply with the parametric values (0.07 µg/l) before January 1, 2024. For the sum of 20 (Σ20) PFAS, (specified in the annex to the draft) the control deadline is January 1, 2025 and compliance with the established parametric value (0.10 µg/l) on January 1, 2026.
The entry into force of this Royal Decree will represent an immense advance at the state level, which until now had a regulatory vacuum regarding the control of these chemical agents.
PFAS control and treatment
The per- and polyfluoroalkyl substances that make up this family of synthetic compounds basically have a molecular structure of carbon chains linked to fluorine atoms. These amphiphilic molecules have a tail with hydrophobic properties and a head, in which functional groups such as carboxylic acid, sulfonic acid, alcohols or others are arranged, giving them hydrophilic properties.
These chemical characteristics give them unique properties. Hence their widespread use as oil and grease repellents and as part of the formulation of products resistant to water, friction, heat and degradation by chemical compounds or bacteria. Until 2008, when their use was restricted, they were widely used in fire extinguishing foams.
It is the strength of the C-F bond that defines the stability of these molecules and makes them almost indestructible under normal conditions.
The European Environment Agency refers to this family of emerging pollutants as consisting of more than 4,700 chemical agents, giving an indication of the complexity of the issue.
All of this prompts a paradigm shift in the study, control and treatment of these compounds. It requires a different approach to that used with other more well-known contaminant families such as hydrocarbons, chlorinated solvents, metals, etc. This change ranges from the initial phases of the development of the sampling plan and selection of specific sampling material to the development of remediation solutions. Due to their extreme stability, sequestration and immobilization techniques are the ones that have proven to be the most successful today. However, it will be the combination of several technologies or the development of new applicable techniques that will achieve greater effectiveness.
Although there are currently no limits set for these compounds in soils or groundwater, the draft Royal Decree for drinking water represents a major step towards controlling them. In Litoclean we are aware of the challenge that this problem will pose for our country and therefore we are part of the PFAS working team of the ITRC Interstate Technology and Regulatory Council (USA), we maintain close communication with local testing laboratories and their network of subsidiaries in Europe and we carry out special projects in our R+D+i department. Therefore, we would be in a position to evaluate the best options in the treatment of these agents to provide optimal solutions to our customers.
