Skellefteå: safe water supply

Access to safe drinking water is a basic human right, and a key component of any community health protection policy. Unfortunately, in 2011 the city of Skellefteå in northern Sweden suffered from Cryptosporidium contamination in their drinking water. Cryptosporidium is a microscopic parasite that causes diarrheal disease. This contamination caused Skellefteå area inhabitants to boil drinking water before use for seven months.

The municipality decided to replace their old water supply systems with a new treatment plant with a design capacity of 28 000 cubic metre per second (m3/d ). Other waterworks updates included water reservoirs and pipelines to the city that treat water. Water treatment for these systems include artificial groundwater recharge followed by oxidation, filtration, and disinfection to ensure high drinking water quality.

The new water source is located about 15 kilometres west of Skellefteå. Ramboll collaborated with Skellefteå unicipilaty and NCC to conduct a feasibility study, produce design principles, optimise processes, and deliver pre- and detailed designs of the plant and other facilities. We also participated in commissioning and optimising of the plant and distribution.

The treatment process was designed to meet feasibility study conditions. During the initial design and detailed design phases, tanks and equipment were selected to manage the required function. However, an initial ambitious redundancy strategy generated investment demands that affected the

cost of the project to exceed the municipality’s budget. During the optimisation phase, the overall cost for the project was reduced approximately EUR 2 million.

The Skellefteå project, once the largest of its kind in Sweden, was unique and complex. Ramboll experts across 10 different office locations made a real difference to this community by bringing our technical capabilities within water resources and water treatment into play.