Drinking water
Water is one of the most precious natural resources and the quality of drinking water has a significant impact on people’s health and wellbeing. Therefore, we understand our responsibility for supplying good quality drinking water to the population and give our best to protect the surrounding natural environment.
Tap water IS drinking water
The quality of drinking water supplied to our customers in the capital city has been keeping the quality level comparable to any Western European country for years now, and so we encourage people to drink tap water. In 2015, we took 2,945 water samples from the consumers’ taps in Tallinn and Saue and carried out 24,500 analyses. So far the best ever result of 99.86% of all the samples being compliant with all the requirements was achieved. Only four samples were not compliant with the quality requirements because of higher iron content. We immediately performed the maintenance works on the water pipeline in the street, and as a result, the repeat samples met all the quality requirements. In Maardu service area, 100% of samples taken from the consumers’ taps were compliant with all the requirements. High drinking water quality throughout the years is a reflection of an efficient water treatment process, preventive activities reducing the number of emergencies on the water network and timely maintenance of water pipelines.
Strict quality control
The quality of drinking water is subject to strict legal requirements. The quality must comply with the Regulation No 82 “Quality and control requirements and analysis methods for drinking water”, issued by the Minister of Social Affairs, pursuant to the Estonian Water Act and the European Drinking Water Directive 93/83/EC. In addition to the legislative requirements, we have also agreed on additional and even tighter quality standards in the levels of service within the Services Agreement concluded with the City of Tallinn. In terms of water quality we have outperformed those requirements assuring good quality of drinking water to each customer. The results of all analyses are public and made available on Company’s website at: www.tallinnavesi.ee –> About Us –> Our Core Business –> Drinking Water Quality.
Water quality is inspected by following the drinking water monitoring programme approved by the Health Board. The programme specifies the sampling points, sampling frequency and the parameters to be analysed. Samples are taken from raw water (Lake Ülemiste, its catchment area and ground water), treatment process and consumers’ taps. There are 120 sampling points in Tallinn including kindergartens, schools and other institutions, evenly spread out across the entire service area.
The Company has a separate laboratory unit, which has been accredited by the Estonian Accreditation Centre since 2001. Laboratory unit consists of a water and microbiology laboratory at Ülemiste Water Treatment Plant and a wastewater laboratory at Paljassaare Wastewater Treatment Plant. Water analyses are made in our water and microbiology laboratory, which is also one of the largest laboratories in Estonia. The quality of analyses is guaranteed by the attested samplers, accredited quality management system (ISO 17025) and modern equipment, as well as the professional staff who enable offering a wide range of services also externally. Water quality is independently monitored by the Northern Services of the Health Board and Supervisory Foundation of Water Enterprises in Tallinn, and our laboratories are supervised by the Estonian Accreditation Centre. In 2015, Company’s water and microbiology laboratories carried out 99,000 analyses all together.
Number of people who drink tap water has been constantly growing throughout the recent years. While in 2011, 48% of our customers drank tap water, in 2015 this figure was already 86%. Growing tendency certainly relies on an excellent water quality and increased customer awareness.
Water treatment
Ülemiste Water Treatment Plant treats water following the treatment scheme widely used worldwide. We are using ozone to improve the quality, odour, colour and taste of water, and this has enabled us to reduce the volume of chlorine used to almost a tenth over a decade. Drinking water must be safe and must not contain any infectious bacteria. For this purpose, we are adding small quantity of chlorine, which is completely safe for human health, but extremely effective for protecting water against bacteria during its journey through the network up to the consumers’ tap.
Surface water quality
Lake Ülemiste is the drinking water source for more than 400,000 people living in Tallinn and its nearest surroundings. Almost 90% of our consumers in Tallinn (City Centre, Lasnamäe, Mustamäe, Northern Tallinn, Kristiine, Haabersti), City of Maardu, Pirita settlement and part of Harku are supplied with drinking water produced out of surface water.
Although Lake Ülemiste serves as the main drinking water source for Tallinners, the natural catchment area of the lake itself is small. Therefore, an extensive water catchment system with a total surface area of nearly 1,800 km2 has been set up in order to provide sufficient supply. To improve the biological diversity and natural habitat of the rivers in the catchment area, thus improving the condition of the whole river system, fish passes were built on Sae, Vaskjala and Kaunissaare dams in 2015. Total cost of this project was more than EUR 350 thousand and the fish passes in Vaskjala and Sae were co-financed through the Cohesion Fund in the amount of EUR 180 thousand.
The quality of surface water sources is monitored on a regular basis according to the programme established in the permit for a special use of water. Our accredited laboratory analyses the quality of water sources in the entire catchment area, we also analyse the water in Lake Ülemiste and the water taken to the lake. We use the results to assess changes and processes in the catchment area and decide upon the need to restock water in the lake.
Ground water quality
Approximately 10% of the population in Tallinn is supplied with drinking water extracted from the ground water sources available in the area. These areas supplied with ground water are Nõmme, Laagri, Merivälja, Pirita, Tiskre, City of Saue, and Tiskre village in Harku Rural Municipality.
All ground water quality parameters are monitored according to the requirements of the permits for a special use of water, drinking water source and drinking water monitoring programmes. If necessary, ground water is additionally treated. Pressure filters installed in the ground water pumping stations for removing excess iron, ammonium and manganese enable to ensure good quality drinking water supply. Water analyses show that treatment significantly improves also the organoleptic qualities of water, such as colour, odour and taste, and increases the oxygen content.
Security of supply and quality
It is essential for the residents to have a good quality service available 24/7. This is why we focus on the continuous improvement of the security of our service.
Water quality at the consumers’ tap is not impacted solely by the age of the network. The water network must be properly maintained in a timely manner and repaired if deemed necessary. We are constantly carrying out maintenance and renewal works on the networks in order to maintain and improve drinking water quality. We clean and flush the network regularly to ensure the supply of high quality drinking water to our consumers. This way sediments get removed from the inner surface of pipes, being of the most important methods of improving water quality in the distribution network. Investments in replacing old water pipes and network extensions have facilitated improvement in water quality at the consumers’ tap and more efficient usage of water resources. In 2015, we reconstructed 5 km of water network.
Preventive actions have also facilitated a year-on-year reduction in leakage level indicating water losses in the distribution network. While the leakage level was very low already in 2014 – 16.14%, the level reached in 2015 – 14.68% – was the best in Company’s history. This means that we saved nearly 500,000 m3 of water compared to 2014, which is the amount of water that Tallinners consume in one week. Compared to the beginning of 2000-s when the level of leakages was nearly 32%, approximately 5,000,000 m3 of treated drinking water is being saved.
