After driving for a while on the truck road to Al Ain and through the desert with merely sand dunes and camels, one arrives at the ISTP2, where we were warmly welcomed by the STP2-staff and directed towards the administration building. Here about 20 very curious members and friends of the BBC gathered, ready to adsorb a lot of information!
In a series of presentations by Mr. Erich Konig, Mr. Dany Fawaz and Mr. Felix Ayllon we have been informed on all the ins and outs of the project, which is a BOOT scheme (Build-Operate-Own-Transfer) and operated under a 25-year concession agreement, after which in theory it will be handed back to ADSSC (Abu Dhabi Sewerage Services Company).
The plant is designed to treat 350,000 cubic meters of wastewater per day (which is roughly half of the total amount of wastewater that is produced here). Abu Dhabi’s wastewater is reaching the plant via the newly build STEP-tunnel (Strategic Tunnel Enhancement Programme) and arrives near the treatment plant on a depth of 80 m below ground. Here is the link to a very interesting Youtube movie about the STEP-project. https://m.youtube.com/watch?v=AUkyCHWtAwc
The wastewater is pumped up and arrives at the plant in the inlet works still on a depth of 15 m, where it undergoes de-gritting and screening. From here is pumped up to headworks and flows further to the plant by gravity. After pre-treatment the wastewater is exposed to the aeration tank where bacteria (sludge) are removing the pollutants. As a result of this more sludge is produced. Sludge and water are separated in the settling tanks. Water will be filtered and disinfected after which it is ready to be send back to Abu Dhabi and used for irrigation. The separated sludge is thickened and stabilised by digestion, dewatered and dried by solar drying.
After a tour around the site we have been treated with a great lunch and we now know where this is eventually going to end up!