Sydvatten AB is a municipally owned company that produces drinking water to 800 000 inhabitants in southern Sweden. The raw water comes from lakes Bolmen and Vombsjön, located in Småland, and generally known for its fine water. Over the past 15 years, the water quality in Bolmen has changed towards more coloured water, with a slight increase in alkalinity. The colour is due to higher content of humus, which in turn impairs the effectiveness of the processes at Ringsjöverket, increases the risk of microbial regrowth in the pipelines and increases formation of disinfection by-products. Rapid raw water quality changes deteriorate the effectiveness of the treatment processes in the waterworks. The time for transportation of the water from Lake Bolmen, through the Bolmen tunnel, to Ringsjöverket is in average one week, so the operating engineers at Ringsjöverket must be able to modify the processes in due time to compensate for the changes in raw water quality in Bolmen. In this project we will investigate and evaluate the possibility to use satellite based water quality information to monitor Lake Bolmen and support the operation processes at Ringsjöverket.

Objectives

1. To investigate, on a more comprehensive level, how satellite based information can be used to measure and monitor the water quality status of Lake Bolmen.
“Investigation of the present quality status, how changes in the quality occurs, what is the dynamics of these processes (hours, days, weeks), seasonal changes (winter?), annual changes and, if possible, how the quality of the tributary basin area affects Bolmen.”
2. To investigate if the same satellite data can be used to measure and monitor the water quality status of smaller lakes in the area.
“Is the spatial resolution enough to produce a good representation of the lakes and is it possible to generate reasonable results with respect to the effect of additional reflectance from the surrounding land.”
3. To evaluate how changes in the water quality, observed from the satellite data, can be used directly to support and enhance adaptive operation at Ringsjöverket.
“How, and how fast, can changes in humus, turbidity and chlorophyll be transferred to the operating engineers at the plant? Is the accuracy and quality of satellite based information sufficient? Costs? Preferably, the data should be available within 1 day after changes have been measured and the quality will be essential with respect to the credibility of the technique. “