VEAS - English - Keyfigures

Main sewer tunnel

Length

42.3 km

Storage volume at 4 m³/s

187 000 m³

Storage volume at 7.5 m³/s

137 000 m³

Transportation time

From Majorstua (Oslo) to Slemmestad

approx. 5 hours

Inlet pumps

8 in total, whereof  2 variable-speed

Capacity with 2m level on suction side

8 x 920 l/s = 7 360 l/s

Capacity with 10m level on suction side

8 x1050 l/s = 8 400 l/s

Screens

4 with bar spacing of

3 mm

Aerated grit chamber

4 with a total volume of

3 320 m³

Flocculation

Takes place in the aerated grit chamber

Sedimentation tanks*

2 at 15.7m x 91.2m x 3.6m deep

10 300 m³

Sedimentation tanks**

6 at 15.7m x 17.7m x 10.5m deep

17 500 m³

Nitrification filters**

24 of  87 m², 4m depth of filter media

Denitrification filters**

24 of 65 m², 3m depth of filter media

Sludge thickening

2 rotary drum thickeners

1 storage thickener of 1 500 m³

Sludge dewatering

4 combined filter presses and thermal vacuum dryers, 140 chambers, 25 mm recess, plate size

1.5 m x 1.5 m

Deep sea discharge

4 diffusers, depth

40 - 55 m

Distribution depth

25-35 m