HS-Vesi invests in Paroinen treatment plant in Hämeenlinna


Hämeenlinnan Seudun Vesi Oy invests in the renovation and expansion of the Paroinen sewage treatment plant in Hämeenlinna. Skarta Finland (former Suomen Maastorakentajat) is responsible for the concrete basin project that includes both excavation and concrete construction.

“The investment is based on new permit conditions. In order to meet the permit conditions for nitrogen, we need more pool capacity. An additional biological line will be built at the sewage treatment plant, consisting of an aeration tank and two clarification basins,” says Operating Engineer Marja Leimu from HS-Vesi Oy.

Improving the efficiency of the treatment plant costs more than EUR 10 million. The value of the Skarta Finland contract is approximately EUR 1.6 million. Work on the site started at the end of October, and according to Leimu, the site should be completed in June 2021.

“The construction of water treatment plants and the related ground and concrete construction fall under the core competence of Skarta Finland. This contract also includes groundwater reduction, in which we have strong expertise,” says Jari Häkkinen, Project Manager at Skarta Finland.

The Paroinen sewage treatment plant receives waste water from Hämeenlinna and Hattula and one third of Iittala’s waste water. The average daily flow rate for the sewage treatment plant has been about 20,000 cubic metres.