Evolution of water and sewerage services in Hameenlinna, Finland, 1800-2000

This paper aims at discussing key long-term strategic decisions and changes concerning the evolution of water and sanitation services in Hameenlinna, Southern Finland. After a debate of three decades the construction of the water and sewage works was completed in 1910. In the early 19th century the hygienic conditions in Hameenlinna were poor since the city was densely built-up and "half marshland, half surrounded by lakes with muddy shores where water flowed so slowly that it appeared to stand still". Groundwater from the Ahvenisto esker area instead of a lake was selected as the raw water source. Water consumption increased rapidly in the 1950s and a surface water plant on Lake Katuma was constructed in 1955, doubled in 1960 but taken out of use 1980. Since 1976 artificial groundwater has been used. The Paroinen wastewater treatment plant began its operations in 1966 as an activated sludge plant. In addition to Hameenlinna's own wastewaters, the Paroinen plant has also purified the wastewaters of Hattula, the neighbouring municipality, since 1974. A supra-municipal water and wastewater services joint-stock company owned by Hameenlinna Town and neighbouring municipalities, Hameenlinna Region Water Supply and Sewerage Ltd., was established in 2001. In 2007 the company takes care of water services in the Hameenlinna region. Water supply is fully based on groundwater or artificial groundwater.