Consultancy services for the sewerage network in Salalah, Oman

This is the outside air ventilation unit which extracts air from the inlet chamber of the pumping station

As a sub-consultant to Associated Consulting Engineers Int’l and Partners llc (ACE), we’re providing modelling services to the Salalah Sanitary Drainage Services Company (SSDC) in Salalah, Oman. The project is titled ‘Design, Supply, Installation, Testing, Commissioning and Operation of Odour Control System for Salalah Wastewater System’. Our services will assist the consultancy team in selecting the sites and sizing of chemical dosing units as well as the operation of the pumps to achieve optimised network operations.

For this project, we’re using our MIKE URBAN software – part of our MIKE by DHI software suite. The MIKE URBAN model includes a detailed description of the sewerage network including all lateral pipes with diameters up to 200 mm. The model also includes all Main Pumping Stations and Area Pumping Stations including all rising mains.

A monitoring program has been undertaken for calibration of the hydrodynamic and hydrogen sulphide (H2S) model. The latter studies the formation of H2S, based on the Wastewater Aerobic-anaerobic Transformations in Sewers (WATS) modelling concept. The WATS model concept is integrated into our MIKE URBAN software package providing SSDC with an integrated and efficient solution to assess both the hydraulics and the formation of hydrogen sulphide in the existing and future sewer network.

Salalah sewer network simulations with the MIKE URBAN model provide the opportunity to verify that the desired standards of services are met with respect to hydraulics and hydrogen sulphide. The model simulation results will support the consultancy team in designing an optimised operation strategy of the network and selecting the sites and sizing of the chemical dosing units in order reduce the risk of corrosion and odour issues caused by the formation of H2S.