Strategic Tunnel Enhancement Programme (STEP)
Wastewater conveyance tunnel, 41 km main gravity sewer and 43 km of link sewers; average flow 800,000 m3/day, ultimate 1.7 million m3/day by 2030 in United Arab Emirates.
Operational
The record
- Country
- United Arab Emirates
- Location
- Abu Dhabi
- Coordinates
- —
- Technology
- Wastewater conveyance tunnel
- Capacity
- 41 km main gravity sewer and 43 km of link sewers; average flow 800,000 m3/day, ultimate 1.7 million m3/day by 2030
- Capital cost
- US$1.9 billion
- Stage
- Operational
- Owner or client
- Abu Dhabi Sewerage Services Company (ADSSC), with ADWEA
- Contractor
- Impregilo, now Webuild (two of the three main tunnel lots, 25 km and ten shafts); Herrenknecht (five EPB shields for the main sewer and nine machines for the link sewers)
- Operator
- Abu Dhabi Sewerage Services Company (ADSSC)
- Finance
- Government of Abu Dhabi
- Award or start year
- 2008
- Commissioned
- 2016
Record last checked 2026-09-18.
History
- 2008
Programme starts
- 2011-04
First tunnel boring machines begin the main sewer
- 2012-12
Last of the five main-tunnel machines reaches its target shaft
- 2013-01
Link sewer tunnelling at full speed
- 2016
Final breakthrough completes all drives and the Al Wathba pumping station is commissioned
Sources
6 references
Every field in the record above is taken from the references below. A field that none of them confirms prints as a dash.
- WaterWorld, Abu Dhabi's wastewater project STEPs closer to completion (25 January 2016). waterworld.com.
- Costing US$1.9 billion and started in 2008; 41 km sewer tunnel and 43 km of link sewers; average flow 800,000 m3/day and ultimate capacity 1.7 million m3/day by 2030; ADSSC managing director Alan Thomson states the link sewers were 95 per cent complete and the Al Wathba pumping station 70 per cent complete with commissioning from mid-2016. Herrenknecht, Abu Dhabi STEP (2011-2016). herrenknecht.com.
- Five EPB shields of 6,310 mm and 6,950 mm for about 25 km of main sewer on lots T-02 and T-03, plus one EPB shield and eight AVN machines for about 43 km of link sewers; first three shields started in April, July and August 2011, the fifth reached its target shaft on 18 December 2012, and the last breakthrough came in summer 2016. Webuild, Abu Dhabi Deep Sewer Tunnel. webuildgroup.com.
- Two of three lots, 25 km of tunnel at about 7 m excavation diameter and ten shafts 40 to 80 m deep, five EPB machines used simultaneously, client ADSSC and ADWEA, flows directed by gravity to the treatment plant at Al Wathba.
- Gulf News, Abu Dhabi completes green main sewer. gulfnews.com.
- MENA Water Review major projects register and PPP pipeline — compiled from procurer publications, development-bank project pages and trade reporting; each record names its source.
Gives the cost as Dh5.7 billion and confirms the 41 km main sewer, 43 km of link sewers and a pumping station beside the Al Wathba plants; the page timestamp is automated and unreliable, so no date is taken from it.