This Design and Build Contract is for Upgrading the Industrial Sewage Treatment Works from 12,000m3/d to 30,000m3/d capacity.
The Industrial Area Sewage Treatment Facility is located approximately 8km South/South East of Salwa Road and currently occupies an area of approximately 15ha, with the existing facilities fenced inside of the site boundary.
The existing plant consist of a inlet works with pre-aeration, fine screens and grit removal, followed by secondary treatment in a modified SBR (SBR – Cyclic Activated Sludge System) biological reactor with tertiary treatment in granular media filters (currently bypassed), disinfection is by chlorination and disposal is to the TSE Irrigation Network (currently being injected in to deep groundwater wells). There is also provision for UV disinfection however this is currently not used.
Surplus Activated Sludge (SAS) is balanced in four tanks with diffused aeration prior to being thickened with gravity belt thickeners, it is then aerobically digested/stabilized before being dewatered with centrifuges. Sludge drying beds are also available for dewatering if the centrifuges are not operating or their capacity is exceeded. After dewatering the sludge is stored inside the sludge cake storage area for further stabilization and contaminant testing before being removed from site.
The existing process shall be retained with the exception of the granular media filters which shall be replaced with a new disc and ultra filtration process. The Contractor shall be responsible for the design, supply, procurement, construction, testing and commissioning of the works, as generally described and in greater detail in the subsequent sections. The Tender shall attend the existing STF and familiarize themselves with the existing STF in every aspect.