Although drinking water produced by the WSC is safe and meets all the relative WHO, EU and Maltese standards, its taste has been the centre of debate many times and for decades. The ‘hard’ taste has been attributed to the chloride and mineral content found in the final blended water supplied to customers. It is WSC’s intention to increase water quality to encourage more people to use tap water for drinking purposes rather than having to revert to bottled water.
With this in mind the corporation has begun a €100 million project to achieve this goal. However, “project” is a bit of a misnomer because there will be a few large separate projects each contributing to one final aim and which include:
1. An upgrade of all RO plants so that they will operate more efficiently and produce better quality water.
2. In tandem with the above upgrade, the booster pumps and header at Pembroke Reverse Osmosis will also be upgraded to ensure that their characteristics correspond with the new transfer line to ensure maximum energy efficiency.
3. Ground water abstraction shall be spatially dispersed and electronically controlled to improve the quality of abstracted water whilst safeguarding the aquifer. This means that rather than abstracting groundwater from a few boreholes and galleries, many more boreholes will be brought online, but these will be remotely monitored in real time so that these same boreholes can be “rested” according to operational needs and aquifer condition.
4. A new RO plant will be built in Hondoq ir-Rummien in Gozo. This will be housed in an existing building thereby avoiding environmental issues and will produce desalinated water for Gozo thereby eliminating the use of the existing undersea pipe from Cirkewwa. If necessary, RO water can be pumped in the opposite direction towards Cirkewwa thereby ensuring better security of supply should any technical problems arise there. The water quality in Gozo will improve whilst ground water abstraction will be reduced.
5. A large underground gallery will be drilled from Pembroke RO to Ta’ Qali Group of reservoirs. This 9.4 km x 3m tunnel will have a 1,200mm diameter main to convey desalinated water to Ta’ Qali thereby increasing the blending potential at Ta’ Qali. Another 800mm pipe will convey blended water back to central part of the island, where a centralised hub feeding via gravity and boosters shall ensure that this quality water can reach all the customers effectively and efficiently. An interesting aspect of this project is that because water will be pumped from Pembroke directly to Ta’ Qali (a rise of around 100m), the WSC will eliminate having to pump water up to Naxxar (around 125m) and then down to Ta’ Qali. This difference of around 25 metres head will save approximately 3.5 Giga Watts of energy and circa €400,000 per annum at current energy prices. This increased efficiency will mean around 1,800 tons less CO2 into the atmosphere every year.
6 Another important benefit of this new connection between Pembroke and Ta’ Qali, is the elimination of lime dosing. At present, ultra-pure desalinated water is slightly acidic and is therefore treated with lime, an alkaline, to neutralize it. However, since the new 1,200 mm pipe will be fibreglass and therefore impervious to acidity, the corporation will be able to pump this acidic desalinated water to Ta’ Qali where it will be blended with groundwater which is naturally alkaline due to Malta’s limestone, thereby eliminating the need for any dosing. This simple and elegant solution will bring about significant savings.
7 A new main will be laid in the Siggiewi area to feed consumers with high quality blended water which will become available by means of the above-mentioned projects.
8 Boreholes in the Siggiewi area shall be combined and their output transferred to the Ta’ Qali reservoirs and blended with Pembroke reverse osmosis water
9 Second class water production will increase and more distribution mains laid to ensure new water is more freely available and used instead of ground water. This will help to improve the quality of said ground water.
Moreover, within the same project and indirectly to further ensure drinking water of even better quality, a number of projects to address problems in the sewer network will also be implemented.
1. Sewer extensions and upgrading thereof will be carried out to minimise sewerage exfiltration to improve the quality of ground water.
2. Sewer mains laid below sea level will be upgraded to ensure minimal sea water intrusion. Less sea water intrusion will mean less saline sewage reaching the treatment plants, which will ultimately lead to better quality second class water. Furthermore, this upgrade will reduce pumping losses and reduce the energy required to produce this new resource.
3. New discharge monitoring stations will ensure the quality of discharges into sewers with the aim of reducing the overall cost of waste water treatment.
All these measures will lead to better quality New Water and hence less dependency on groundwater for irrigation purposes.
|Operational Programme I – European Structural and Investment Funds 2014-2020“Fostering a competitive and sustainable economy to meet our challenges”|
Project may be considered for part-financing by the Cohesion Fund
Co-financing rate: 85% European Union; 15% National Funds