Published the 27/08/2018
When there is a combination of severe water shortage and an increase in demand, the use of non-conventional sources of water could provide an alternative option for supplying large volumes of this resource. Purified waste water is the only resource that becomes more plentiful as the needs increase. These local solutions can be applied for uses where drinking water is not necessarily required, such as agricultural irrigation, the irrigation of golf courses, urban and industrial uses, replenishing the aquifer. This will allow the potable water to be reserved for essential uses. Recycling treated wastewater opens up a whole range of uses for non-conventional types of water.
This practice has been developed in some parts of the world: e.g. Israel, California, Australia, Spain, Tunisia, Cyprus and the Gulf states…. In Windhoek, Namibia, wastewater is even recycled on a large scale to produce drinkable water, providing proof that there is no technical limitation for this principle. Nevertheless, treatment that allows a very high bacteriological quality level to be obtained is very expensive and can only be economically worthwhile in the absence of a less costly alternative.
In France, there are some forty or so wastewater reuse operations: in the islands of Îles de Ré, Noirmoutier, Oléron, Porquerolles, Clermont-Ferrand, Pornic, Saint-Maxime and Guilvinec. According to an appraisal analysis issued by the General Commission for Sustainable Development (CGDD) in June 2014, this would represent an average daily volume of 19,200 m3 of recycled water, compared with 931,000 m3 for Spain and 958,000 m3 for Israel. The use of other types of water (grey, raw and mine water) is practically banned at the present time, except for industrial applications. It should be remembered that the French Code of Public Health stipulates that only safe drinking water can be used inside the home (art. R.1 321-1). Outside the home, a few exceptional operations are being adopted. This occurs in Dijon, for example, where the grass and trees alongside a new stretch of tramline are being irrigated with mine water taken from the rising water table in an underground car park.
The first reason is that the country is unaware of the fact that there exists an acute long-term shortage of this resource. “Nevertheless, certain areas (islands, small catchment areas, aquifers of a limited capacity) lack resources of sufficient quantity and quality to meet their needs, explained François Brissaud, professor of the Montpellier II University. All the more so because the development of certain irrigated crops, maize in particular, aggravates the competition for access to this water resource, with the added risk of depleting certain aquifers and rivers”. Other players in this field consider that the regulations currently in force on the reuse of purified wastewater represent the main obstacle standing in the way of this re-use.We should also remind ourselves that, prior to 2010, the situation regarding the rules and regulations was unclear: the principle was approved by article R. 211-23 of the Environmental Code. However, the draft decreedefining the conditions for implementing the reuse projects, was rejected and modified several times over a period of fifteen years.Finally, the decree of 2nd August 2010 relating to the use of this type of water for the irrigation of crops or green spaces provided authorisation for gravity or drip irrigation. It defined four categories for the use of treated waste water according to its level of sanitary quality. The most demanding, category A, allows the irrigation of non-processed market garden crops and the irrigation of green spaces open to the public (such as golf courses); the less demanding, category D, relates to the irrigation of timber forests with controlled public access.
On the other hand, the decree of 2010 only provides authorisation for sprinkler irrigation, the system most adapted to green spaces, golf courses and areas of large scale arable farming, to be carried out on an experimental basis and under specific conditions (prior investigations conducted by Anses –a French governmental agency dealing with the health and safety aspects of food, the environment and work place –using the results of small-scale pilot tests carried out over a six-month period). After Anses released a long-awaited appraisal in 2013, a modifying by-law dated 25th June 2014 removed from the statutes the application dossier requesting experiments to be carried out on sprinkler irrigation, replacing it with new technical specifications. It imposed restraints on distance, terrain and wind drift and prohibited public access to the site for up to two hours after irrigation. Finally, it stipulated that the authorised operations must comply with these obligations within two years, i.e. by June 2016. Recently, the ministries, nevertheless, has made it known that this deadline would be extended.
“This is now placing in great danger an industrial sector, which has all the required expertise and know-how and there are high international stakes, deplores Wladimir Gauthier, secretary-general of the UIE. While this practice has been widely developed in Europe and other countries and forty or so installations have been operating for twenty years in France with no potential danger, the regulations of 2010 and 2014 have brought to an abrupt halt plans for any new projects and placed the maintenance of existing installations at risk.”According to simulation tests carried out by Irrigants de France, applying these by-laws to the operation carried out over the years in the black Limagne region (see inset on p. 26), near Clermond-Ferrand, would reduce the total surface area irrigated by 30 to 40%.
In collaboration with Irrigants de France, FP2E, Syn-tec-Ingénierie, the French Golf association and other players, UIE has redrafted the proposed amendment. They recommend stricter measures for guaranteeing the safety of quality levels A and B, bringing them close to bathing water quality and compatible with most uses, quality classifications C and D being reserved for specific uses where sprinkler irrigation is not involved, as they pose no risk to public health and safety or the environment.
These professionals also recommend defining an ultra-pure A+ water quality for very sensitive uses. Citing the variations in the quality of raw water and the uncertain forms of measurement, they are hoping to abandon the concept of log removal values for three parameters (faecal enterococci, F-specific RNA bacterial phages and bacterial spores) and replace them with other limits expressed as a percentage concentration.They are also asking for a revision of the constraints imposed by peripheral factors (wind, distance, irrigation equipment, etc.) which are “impossible to apply in the field, being uncontrollable and ineffective from a health and hygiene point of view”. “For example, a wind speed greater than 15 km/hour must automatically trigger the shutdown of sprinkler irrigation, explained Valentina Lazarova, expert in wastewater reuse at Cirsee, the Suez Research Centre. This does not happen anywhere else.Compliance with this provision has a significant cost and would be almost catastrophic for irrigation in somewhat windy, coastal areas, for example.Tout cela, sachant que la mesure précise locale du vent est un défi (phénomènes de mini-bourrasques, etc.).And this is despiteknowing that the precise measurement of local wind conditions is very challenging (freak gusts of wind, etc.).”»
And reducing the size of the authorization dossier, clarifying the responsibilities of the various players involved and extending the scope of the decree to cover other uses (road washing, fire-fighting, restoration of wetlands) with specific water quality criteria defined for each one of these uses. Elles ont été présentées dans le cadre du groupe « eau » du Comité de filière des éco-industries (Cosei). They were submitted during a meeting of the working group dealing with « water » at the Eco-Industries Strategy Committee (Cosei). « Ce qui est sur la table est raisonnable et responsable », estime Wladimir Gauthier.“What is on the table is reasonable and responsible,” said Wladimir Gauthier.The Minister of Ecology and the Finance Minister announced on 2nd April that they are willing to revise this regulation and discussions began during a working group involving ministries and stakeholders. « La réglementation actuelle est justifiée s'agissant des bactéries, virus et parasites, y compris l'exigence d'abattement microbiologique sur trois paramètres, estime un expert reconnu.“The current regulations are justified in terms of defining the presence of bacteria, viruses and parasites, including the de-activation of microorganismsbased onthree parameters," said one recognised expert. Les industriels dénoncent une réglementation trop contraignante et, en même temps, ils sont dans une surenchère pour vendre de l'équipement de traitement super-performant.Manufacturers are criticising regulations that are too restrictivewhile, at the same time, they are locked into a situation where they are trying to sell super-effective water treatment equipment.Le souci, c'est qu'il n'y a aucun intérêt à utiliser de l'eau usée plus chère que de l'eau potable.The concern is that there is no point in using wastewater if it becomes more expensive than drinking water.On the other hand, current regulations do indeed err on the side of caution if we consider the constraints on distance and restrictedaccess for two hours after irrigation ...”The FNCCR, which is a member of the working group, has adopted a more balanced standpoint. « Il est vrai que certaines dispositions dans la mise en œuvre de l'aspersion ont un caractère très contraignant, constate Laure Semblat, chargée de mission à la FNCCR."It is certainly true that some provisions relating to the implementation of sprinkling systems are very restrictive,"stated Laure Semblat, head of mission at the FNCCR. « Dans le but de voir les contraintes allégées, les industriels proposent d'aller vers de l'ultra-qualité d'eau », souligne-t-elle.“With a view to seeing an easing-up of the rules, manufacturers are proposing a move towards ultra-high quality water,” she said. « Sans être opposés à la création d'une telle catégorie de qualité d'eau associée à des contraintes moins sévères, nous ne souhaitons pas qu'elle devienne la référence imposée.“Without being opposed to the creation of such a category of ultra-pure waterquality with less severe constraints, we do not want it to become the benchmark.This involves investing in highly efficient units, thus increasing the cost of producing reusable water,” she continues. « De plus, imposer une qualité A+ pourrait conduire à remettre en cause l'équilibre économique des installations existantes, dont le maintien est l'une de nos préoccupations premières.“Moreover, imposing an A + quality could have a crippling effect on the economic situation of the existing facilities, where maintenance is one of our main concerns.Sachant que les contraintes fixées sont liées principalement à la méconnaissance des risques liés à la projection de particules dans l'air (aérosols), nous souhaitons surtout qu'un effort soit produit pour améliorer le niveau de connaissance sur le sujet, ce qui permettrait peut être , in fine, de s'affranchir de certaines barrières de séKnowing that the constraints are mainly imposed because of the lack of knowledge about the hazards associated with the release of fine sprays into the atmosphere (aerosols), we would like to see an effort made to improve the knowledge in this respect, which,ultimately, could allow for certain barriers to be removed.”