AS Tallinna Vesi’s operational performance in the 3rd quarter of 2019

Tallinna Vesi has shown an excellent operational performance in the 3^rd quarter of 2019. The company managed to maintain consistent and high-quality drinking water together with effective wastewater disposal.

Continuous supply of high-quality drinking water and more sensitive testing methods

The quality of drinking water in Tallinn remains very good, the water samples taken from customers’ taps during the 9 months of 2019 were 99.1% compliant with all requirements. The compliance in the 3^rd quarter was 98.0%, which was somewhat lower in comparison with the result of the same period last year. Whereas the quality of drinking water leaving the water treatment plant continues to be excellent, the slight drop in the water quality at customers’ taps is attributable to the changed analytical methods used by laboratory. The new analytical method is significantly more sensitive, which provides the water company with much more accurate information than before. As a result of those tests, Tallinna Vesi has made further developments in the water network and improved the effectiveness of maintenance system in order to ensure consistent supply of high-quality drinking water.

The only sanitary guarantee of the drinking water, produced from surface water and supplied to the water network, is the chlorine added to the water at the very last treatment stage. It is common practice internationally to use chlorine in order to ensure the availability of high-quality water also to the consumers at the further end of the network, where water retention time in the network is longer. In that respect, Tallinna Vesi drew special attention to the measurement and dosages of chlorine in the 3^rd quarter, raising chlorine levels in the drinking water at places. This is particularly important during summer due to higher water temperature in the network, in which case chlorine reacts very quickly and disappears from the network before water reaches the consumers.

The dosages of chorine added to the water remain within the limits set forth in legal requirements – according to the renewed drinking water regulation the concentration of residual chlorine in the drinking water leaving the treatment plant is allowed to be up to 1 mg/l. Unfortunately, such changes have caused some increase in the number of water-related customer contacts due to consumers’ concerns about changes in the odour and taste of water. We have explained that chlorine continues to be added to the water in very small dosages and that tap water is safe to drink and completely harmless to human health.

Reliable service

Low water losses and reduced time of average interruptions to water supply, are a testament to a stable and continuous service provided to our customers. In the 3^rd quarter of 2019, the average water disruption time per property was only 3 hours and 4 minutes. Incurring interruptions, often caused by 3^rd parties, within our extensive water network are inevitable, we are committed to do our utmost for customers, and minimise the inconvenience caused by the repair works. We value water as one of the most important natural resources, which must not be wasted. The level of leakages in our water network was 13.07% in the 3^rd quarter, representing an excellent result. The result of 9 months is even better – 12.49%.

This year Tallinna Vesi has had few instances where the company was unable to restore the water supply after repairs by the exact time promised to customers. Unfortunately, some of those interruptions affected quite a large number of customers, causing the number of failed promises to be higher than last year. Such instances have not become more frequent, nevertheless we are committed to analyse those and recognise the consequent effect on our customers. 

We continue to make targeted capital investments, renovating or replacing assets on the basis of previous condition surveys and performance data, to ensure the continued reliability of the network.

We care for the environment

The issues with the sewerage network have also reduced. In comparison with the 3^rd quarter last year, the number of sewer blockages for the 3^rd quarter dropped from 148 to 95. At the same time, we are concerned about the growing trend in the volume of domestic waste ending up in the wastewater network. As waste in sewers can cause serious and unpleasant blockages, or even lead to environmental pollution, Tallinna Vesi continues to make efforts to raise public awareness about wastewater by organising tours at the plant, open days and by bringing the topic up in media.

In the 3^rd quarter of 2019, the treated effluent at Paljassaare Wastewater Treatment Plant was compliant with all quality requirements. With the purpose to assess the treatment efficiency and the quality of wastewater, we continuously monitor for pollutants, in both the incoming wastewater and final treated effluent. Wastewater laboratory analyses the samples taken from different stages of the wastewater treatment process, and the information received thereby allows us to further improve the treatment efficiency and ensure final effluent quality.

Eliis Randver
Head of Customer Relations and Communication
Tallinna Vesi
(+372) 626 2275
Eliis.randver@tvesi.ee