The quality of tap water is a matter of great public interest on which from time to time there are various articles both in the academic domain and in the press. An article featured on Sunday 16 June 2019 in the Sunday edition of Maltatoday linked Perchlorate to tap water on the basis of research conducted in 2012-13.
On this matter, the WSC laboratory would like to outline a number of details, primarily that there is absolutely no cause for concern or alarm on this matter. The tests conducted by the ISO Accredited WSC Laboratory in 2017 directly on groundwater prior to blending with Reverse Osmosis (RO), found that the levels were around 50 times less than the WHO recommended limit.
When Ground Water is mixed with RO water (currently at 40% Ground Water and 60% RO) these quantities are further diluted. Moreover, these negligible amounts will be further reduced through the multimillion Euro EU funded upgrades that are being implemented by the Corporation that will ensure the most ideal blend of potable water (30% Ground Water and 70% RO). Therefore, not only there is no cause of alarm but the situation is expected to further improve.
In terms of detail, along the years, the Water Services Corporation’s Laboratory carried out several tests for perchlorate in its water sources, with only 46% of these Ground Water sources, giving trace readings. The maximum value reported in Ground Water was that of 2.7µg/L, with an average of 1.4 µg/L, these are way below the 2017 WHO updated guidelines that suggest a level of 70 µg/L. The concentration in tap water averages less than 0.7 µg/L and will go down to below detectable limits once the EU major project is fully implemented. Therefore, even if one had to resort to the most stringent limits in the USA as mentioned in the Article, Malta’s tap water would still be 100% safe for consumption.
In addition to the above ad-hoc tests which are being intensified, potable water testing is governed by EU legislation that includes regimented testing on a monthly basis. The amount of sampling conducted by the Corporation is proportionate to the volume of water produced, and to ensure even better monitoring, WSC also monitors its entire network on a monthly basis. Further to this, the laboratory also carries out the obligatory audit monitoring. The laboratory processes over 13,000 samples and carries out just under 103,000 different tests per year.
All the samples collected, as part of the monitoring and compliance regimes, are within the requirements of the directive, and thus safe for drinking. Microbiology, chemical, and radioactive parameters are all within the stipulated limits, and thus potable water from the mains is up to the necessary requirements to ensure safety for consumption.
Potable water is tested locally at the laboratory within the head office of Water Services Corporation in Luqa, where a team of scientists and lab technicians, carry out daily analysis to achieve the necessary requirements. The laboratory is covered by ISO 17025 accreditation, and is one of the biggest laboratories in the Maltese Islands, with over 40 accredited tests, in various water matrices, ranging from drinking water to wastewater.
The laboratory employs a team of 6 scientists, 10 technicians, 3 samplers and 5 support staff, whom on a daily basis ensures that several samples are collected and analyzed from various sources such as Reservoirs, Pumping Stations, village points and also Reverse Osmosis plants. The staff undergoes continuous training and competence checks to ensure that the strictest requirements are adhered to as expected from ISO 17025 accreditation bodies. The laboratory is also audited annually by the National Accreditation Body, which forms part of the European Accreditation body.
The results of the tests carried out by the laboratory are published on a monthly basis on www.wsc.com.mt