Reduction of non-point loading

The basis of the restoration of Lake Tuusula is that the non-point loading of the lake is to be reduced considerably. There is a constant loading from the catchment area e.g. due to natural leaching, agricultural run-offs, scattered settlements and densely populated areas.

There have been attempts to control the agricultural water pollution more efficiently by using EU subsidies and by co-operating with the farmers. A farm query is conducted to study the possibilities to offer financial support also outside the EU framework to measures that reduce the water pollution.

One way of reducing the non-point loading is by building wetlands and settling basins where the nutrients can be stopped. Consequently, several wetlands and settling basins have been constructed on the catchent area with the help of EU special funding, with the project funding and also with private funds.

Also the purification of the storm sewage is going to be studied. In its first stage measurements were taken of the storm sewage of Järvenpää to decide how much harmful substances for the lake it contained.

At the moment, in the catchment area of Lake Tuusula there are about 1 800 people whose households are hot connected to the municipal sewage disposal system. This does pose a threat to the lake’s condition since the phosphorus contained in the scattered settlements wastewaters is more suited for the algae production than the one contained in agricultural run-offs. Therefore, it has relatively a larger effect on the eutropication of the waterways than the estimated 15 % would suggest.

Being connected to the municipal sewage disposal system is the principal solution in areas that are within reasonable distance from the sewage line. In little townships household sewages could be connected to the municipal sewage disposal system by transfer sewage or to a joint local cleaning system along a joint sewage. In scarcely populated areas individual solutions have to be found for the treatment of wastewaters.

A general plan for the water management of the scattered settlement areas was formed in October 1999 as a result of the HAAVE -project led by the Uusimaa Regional Environment Centre. It was ordered by the Tuusula municipality and the town of Järvenpää and carried out by Maa ja Vesi Ltd in co-operation with the Regional Environmental Centre. However, the main responsibility of the HAAVE-project remains on the municipalities and is tied to the budget that they can allocate each year to their sewage system and water management. In addition the municipalities also have their separate general plans for the water management alongside the HAAVE-project.

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