The Valmet DNA automation system plays a key role for Turun Seudun Vesi to ensure it can produce and distribute naturally treated household water to nearly 300,000 people and numerous industrial companies in the Turku area.
Turun Seudun Vesi is a wholesale water company owned by nine municipalities in Finland. It produces clean water using organic methods with very few chemicals. The raw water comes from a river about 100 kilometers north of Turku. Pre-treated river water is infiltrated into the sand and gravel aquifer in an esker area. After the minimum residence time of three months, the water is pumped up as good-quality groundwater through the 13 production wells presently in use.
“The production area is modeled with a three-dimensional hydrogeological model. Based on this, we have developed a 60-layer groundwater flow model. It has millions of cells, each with detailed parameters that describe the quality and properties of the formation. We really know every water molecule’s journey,” says Aki Artimo, CEO of Turun Seudun Vesi.
Surface water cannot be used as household water. It always requires processing. In practice, either chemical purification or artificial groundwater recharge is used to remove the unwanted substances. However, chemicals can degrade the water quality. In Turku, a minimal amount of chemicals is used in treating water, so it can be said the water is almost organic. A full-scale chemical water treatment plant located in Turku is only used as a backup facility.
A Valmet DNA automation system has been in use since the water company started operating. From one control room, an automation system is used to control and operate the plants. Since the range of activities is more than a hundred kilometers wide, most of the plants are planned eventually to be unmanned.
Predictive control technology ensures there is enough water in the network even during times of peak consumption. Also, certain alarm parameters are specified for the automation system, which monitors the water quality closely. If changes occur, the operator gets an alert and is able to take care of the situation.
“The best feature of Valmet DNA is its reliability. I get the right information at the right time, and I can intervene in the process if needed,” Markku Hyytiä says. He gives an example – if the basins are full, he can manually control the transfer of water simply by closing or opening valves.
According to Artimo, automation data can also be used for sales invoicing, since Valmet DNA allows them to see how much water has been delivered at any point of sale. Data is transferred separately to the billing system. In addition, regular reports can be prepared for the authorities. Part of the data is obtained directly from the automation system, while some is collected from other sources.
Artimo sums the situation up: “The most important thing for us is the reliability of the plant. With the automation system, we can maintain production and distribution. Everything must work smoothly around the clock. It is essential for us that risks are under control. Valmet has been a reliable supplier, and we are pleased with their services.”
To ensure continued smooth operation, Turun Seudun Vesi has agreed on an automation system upgrade with Valmet.
TEXT: Soili Städter
PHOTOS: Soili Städter and Turun Seudun Vesi
Article published in Forward magazine 1/2019.