Sustainable energy exploitation systems
Certain systems for the exploitation of sustainable energy may influence the quality of the water resources used for producing water for human consumption. The Agency therefore drafted:
- a report in 2011 on the main risks for ground water resources due to the installation, operation, maintenance and abandonment of various sustainable energy recovery systems (geothermal facilities, solar panels and wind turbines) in catchment protection zones for water intended for human consumption;
- guidelines in 2008 for the installation of hydroelectric turbines on pipes for raw water used to produce water for human consumption, on pipes for water undergoing processing, and on pipes for water for human consumption, so that the authorisation application dossiers for these systems may be assessed and processed by the Regional health agencies;
- guidelines in 2008 for the assessment of the safety of heat transfer fluids that may be used in heat treatment facilities for water for human consumption operating on simple exchange, since this practice has been growing with the use of solar water heaters .
Use of seawater for the production of water intended for human consumption
As part of the French plan to manage water scarcity (2014), four areas of work have been identified to restore the flexibility needed for the drinking water supply and to deal with recurrent droughts due to climate change. One of these areas concerns the emergence of innovative projects in order to diversify the resource, particularly the desalination of seawater for the production of drinking water.
In accordance with the French Public Health Code (provisions of Article R. 1321-6), prefectural authorisation is required in order to use water for the production of water intended for human consumption. In the specific case where the resource used to produce water for human consumption is seawater, the regulations state that all projects to produce drinking water from seawater must be submitted to ANSES for an opinion.
In 2009, the Agency drew up guidelines on how an applicant should prepare an application for authorisation so that the documents submitted correspond to those expected by the experts.
Recycling of effluents involved in the processes to treat water intended for human consumption
Treatment processes used in the production of water intended for human consumption may generate large quantities of liquid effluents (e.g. effluents from deconditioning of membranes, water from washing filters, effluents from disinfection or regeneration of treatment media, saturated treatment media, etc.).
Because the reuse of treatment effluents in the drinking water production process may result in microbiological contamination of the treatment media, the Agency may be consulted on projects to authorise water purification processes using these methods.
In 2014, ANSES published a method for analysing health risks linked to the recycling of washing effluents in order to help applicants to prepare their authorisation application dossiers and to help the regional health agencies in the expert assessment of these applications. The opinion and report were revised in June 2017 (PDF) (in French).
Recycling of treated wastewater
Treated wastewater is recycled in certain countries where there is a shortage of water resources (particularly the Maghreb countries, Israel, Australia and the United States). In France this is considered to be an interesting alternative for irrigating crops or watering green spaces. This practice would preserve water resources, especially during unfavourable weather conditions (prolonged drought) or in areas with limited availability of water resources for the different uses.
However, since urban wastewater treated by sewage plants contains various pathogenic microorganisms and potentially toxic organic and mineral chemicals, the conditions for its reuse for irrigating crops or watering green spaces are governed by a regulatory framework in order to prevent potential health risks associated with this practice.
A three-stage expert appraisal
In 1991, a structural proposal was made by the French High Council for Public Health (CSHPF). Based on this, the authorities drew up a draft regulation and submitted it for an opinion to the French Food Safety Agency (AFSSA). In 2008, the Agency issued an initial opinion regarding the health risks for humans and animals of oral route exposure to treated wastewater used for agricultural irrigation or watering.
In 2010, the Agency supplemented this expert appraisal with an assessment of the risks linked to the reuse of a specific type of wastewater (effluents from animal by-product processing plants) for the irrigation of crops intended for human or animal consumption. .
Then in 2012, ANSES completed the two previous expert appraisals and published an assessment of the risks associated with respiratory and mucocutaneous exposure during green space sprinkling operations using recycled treated wastewater, or during sprinkling operations using treated wastewater for washing roadways.
Reuse of greywater
Greywater is not drinkable since it may contain microbiological or physico-chemical contamination. It consists of water from showers, bathtubs, bathroom sinks, washing machines, and sometimes kitchen sinks and dishwashers. Over the last few decades the practice of treating and recycling greywater has become widespread in certain warm, arid countries whose water resources are insufficient to cover all domestic purposes.
Examples of domestic use of treated greywater include flushing toilets, washing laundry, cleaning floors, etc. The reuse of treated greywater for domestic use has become increasingly popular in France, but has also led to questions due to the fact that authorisation is only granted by prefectural waiver.
In the opinion and report published today, the Agency considers that the practice of recycling greywater in the home must be regulated, and that it must only be considered for strictly limited uses in geographical environments that are durably and repeatedly subject to water shortages. Individuals (building residents, occasional users, workers) must also be informed and trained in the required conditions of use of greywater in order to minimize the risks of this non-potable water on the premises.
The collection and use of rainwater for domestic purposes has become increasingly popular over the last several years, the goal being to save water and/or control runoff and flooding. The ministerial order dated 21 August 2008 on the collection of rainwater and its use both inside and outside buildings provides for the possibility of using collected rainwater run-off from inaccessible roofs on a trial basis for clothes washing, provided that suitable water treatment systems have been set up, and that certain other conditions are complied with.
The Agency conducted an expert assessment of the health risks associated with use of rainwater for washing laundry in the home. The identification and characterisation of the full range of major micorobiological and chemical hazards was not possible due to the lack of data available, either published or unpublished. Therefore, assessment of the risks could not be conducted. In this context, the Agency advises against using rainwater for laundering items for vulnerable groups, including young children, immunocompromised individuals, people receiving hospital care at home, etc. ANSES also advocates drafting a good practice guide on laundry washing, regardless of the type of water used, to help inform people about the laundry care practices (sorting laundry, temperature, ironing) to be implemented in order to optimise laundry hygiene.
Artificial groundwater recharge
Groundwater resources must fulfil users' needs at all times. However, over the last few decades, these resources have suffered from increasingly frequent drought periods and natural recharge areas have diminished, leading to the implementation of more frequent water usage restriction measures at the local level.
The practice of recharging groundwater can fulfil various objectives, including qualitative and quantitative maintenance of the groundwater resources used for the production of water for human consumption, crop irrigation, and the watering of animals. This artificial recharge technique, which has already been implemented in France and in other countries, needs to be evaluated from a health risk point of view. Since groundwater is under the influence of the water used for recharging it, an assessment of the health risk for its users should therefore be conducted.
In an Opinion issued in June 2016, ANSES considers that this technique could be used to counter the decrease in groundwater resources under certain conditions:
- artificial recharge of groundwater must not degrade the quality of groundwater nor require additional water treatments after abstraction for the same use relative to a non-recharged resource;
- all recharged groundwater resources must be compatible with their current or future use to produce water intended for human consumption, in order to avoid undermining these resources for the future;
- the quality of the recharge water must be better than or at least equivalent to the quality of the groundwater.
Moreover, it must be possible to use the artificial recharge system in a sustainable manner, which in particular requires good management of the recharge site, monitoring of contaminants that may be present, etc. Artificial recharge of groundwater must not impact the achievement of the environmental objectives ensuing from the Water Framework Directive for the body of groundwater and projects for artificial recharge must be based on a specific need related to the target water resource (periodic shortage, balance between demand and the resource available).