New treatment plant in Skellefteå, Sweden

Ramboll was the lead consultant for the project “New Water Supply for Skellefteå Municipality with surrounding communities”. Access to safe drinking water is a basic human right and a key component of an efficient policy for health protection. However, five years ago the city of Skellefteå in Northern Sweden suffered from Cryptosporidium in the drinking water. Cryptosporidium is a microscopic parasite that causes the diarrheal disease, so for seven months the inhabitants had to boil their drinking water before use.

The municipality decided to replace the old and worn waterworks with a new treatment plant (Design capacity 28 000 m3/d), water reservoirs and pipelines to the city of Skellefteå, that treats the water with artificial groundwater recharge followed by oxidation, filtration and disinfection to ensure high drinking water quality.

The new water source is located about 15 km west of Skellefteå. Ramboll worked together with the client and the contractor in a partnering contract and has performed a feasibility study and produced a principle design, optimized the process, and delivered pre- and detail design of the plant and all other required facilities. Ramboll also participated in the commissioning and optimization of the plant and distribution together with the client.

The treatment process was designed to meet the conditions set in the feasibility study. During the work with principle design and detail design phase basins, tanks and equipment were selected to manage the required function.

However, the initial ambitious redundancy strategy generated investment demanded such as several by-passes with pipes and extra equipment such as pumps for dosing chemicals etc. that affected the cost of the project to exceed the municipality’s budget. Due to the optimization phase the overall cost for the project could be reduced with approximately 2 MEUR.

The project was the largest of its kind in Sweden, and our project team included experts from 10 different offices. In the end The Skellefteå project was a unique and rather complex project where Ramboll made a real difference by bringing our strong capabilities within water resources and water treatment into play.