Syvab Himmerfjärdsverket

• • • • • • Sweden's fifth largest wastewater treatment plant (WWTP) The WWTP has been in operation since 1974 The treatment plant is located 40 km south of Stockholm Our owners are the municipalities Botkyrka, Nykvarn and Salem, Stockholm Vatten VA AB and Telge i Södertälje AB 350 000 people are connected to the plant We treat 120 000 000 liters of water every day (= 1300 liter water per second = 6,5 bathtubs/second)

The tunnel system

• • • • • The water flows through a 55 km long tunnel to the plant The water flows through six municipalities (Stockholm, Huddinge, Botkyrka, Salem, Södertälje and Nykvarn) The water flows by gravity The tunnel slope is 1 meter / kilometer (1 ‰) It takes eight hours for the water to reach the treatment plant

The Himmerfjärden WWTP

3. Filtration 2. Biological 1. Mechanical och chemical

We care about our environment

We produce biogas and biosolids

The biogas is used for: • Heat up our offices and digesters • Gas engine for blowers • Sludge dryer • Vehicle fuel The biosolids are used for: • Forest fertilizer • Agriculture • Golf courses • Land restoration • Bio fule

Syvab