Project Reference: ERDF 304. Priority Axis 4 – Climate Change and Resources Efficiency
This project is already providing an alternative water resource to private groundwater abstraction. In other words it will lessen the pressure on our underground aquifer due to its over-utilisation.
At present the three main sewage treatment plants are discharging treated sewage into the sea. Since it is treated it causes no harm to the environment but is a waste of a potential resource. Therefore, three polishing plants are being built at these STPs which will further treat this treated sewage to very high quality standards. This “New Water” will be suitable and safe for various non-potable purposes.
In Gozo we will be polishing all 4000m3 per day of treated sewage effluent produced which will yield around 3200m3 per day of highly polished reclaimed water (the remainder will be reject and discharged to sea).
At the Iċ-Ċumnija plant we have started polishing treated sewage effluent and are supplying high-quality water to farmers in the Mellieha and Manikata areas. We will eventually be able to supply around 6400m3per day.
In the south, out of the 55000m3 per day of treated sewage effluent, we will be polishing 12000m3 per day with an envisaged output of 9600m3 per day.
It is interesting to note that during the winter rainy season when demand for new water is very low, this will be treated to an even higher standard and will be used for aquifer recharging. This, therefore, is the WSC’s two-pronged strategy to address the chronic over-extraction problems of our groundwater sources. One prong of this strategy is the actual provision of an alternative very good quality supply of water to farmers, while the other prong will try to reverse decades of damage to the aquifer.
The above strategy was formulated after years of testing and experimentation in various locations. The most recent is the test facility at Bulebel where experimental aquifer recharge is being carried out under strictly-controlled conditions.
The WSC also has problems with seawater intrusion into sewer mains situated below sea level. Sea water entering the sewer system not only causes salinity issues at the STPs, but it also increases pumping costs. Further measures are to be taken to reduce this seawater intrusion by replacing and/or relining certain sewer mains. The expected reduction in salinity will also positively influence the quality of the “New Water” explained above