Project Description
The existing activated sludge plant at Tubli Water Pollution Control Centre (WPCC) was designed to treat a daily flow rate of 200,000m3/d. However, due to the continuing rapid growth of Bahrain, the flow rate into the works was in excess of 300,000m3/d and this is only expected to increase in the future.
The Ministry of Works requested Bluewater Bio to provide a solution that, in the first instance, alleviated the overloading problems and met the stringent TN standards required of TSE production, all within the confines of existing site boundary.
The HYBACS® upgrade comprises the conversion of 2 of the 10 aeration lanes and 4 of the 12 clarifiers into a HYBACS® plant, by installing 42 SMART™ units upstream of the aeration lanes. The upgraded HYBACS® plant now treats 100,000m3/d meaning that the two aeration lanes, originally designed for 40,000 m3/d, have a 150% uplift in capacity.
| Project Name: | Tubli WPCC (Phase 2) |
| Client: | MoW - Bahrain |
| Capacity: | 120 MLD / 420,000 P/E |
| Project Driver: | Overloaded plant and environmental concerns |
| Project Scope: | DBO Contract |
| Main Contractor: | Bluewater Bio |
| Main Contractor: Bluewater Bio Contract Conditions: | MoW standard contract (based on FIDIC) |
Project Highlights
- Low-cost upgrade – utilising existing assets
- 3-fold increase in capacity
- Power consumption only 47W/PE.day (165 W/m³
- Enhances the environment in Tubli Bay
- Enables 120 MLD for reuse and irrigation
- Highest standards of H&S
(zero lost-time incidents)
Scope of Works
Design, procurement, construction, installation, testing, commissioning, operation and maintenance of: new feed pump station, SMART™ plant, conversion of aeration lanes from surface aerators to FBDA,
new blower building, new sludge pump station, conversion of existing clarifiers into HYBACS® plant, 2 x new substations, associated SCADA control system, HV power distribution system. Following successful completion Bluewater Bio were appointed to operate and maintain the HYBACS plant at Tubli.
Project Duration
24 months, completed October 2021
Client Contact
Client organisation: Bahrain Ministry of Works
Contact person: Musab Al-Sayed (Project Manager)
Contact Info: +973 (0)3994 3882 | musabskq@works.gov.bh
Performance Test Results
| Parameter | Guaranteed | Actual |
| Flow (MLD) | 120 | 121 |
| COD (mg/l) | 60 | 17 |
| SS (mg/l) | 20 | 3.3 |
| Ammonia (mg/l) | 1 | 0.4 |
| Total nitrogen (mg/l) | 10 | 5.9 |
| SSVI (ml/g) | - | 54 |
| Power usage (kWh/week) | 280,000 | 140,000 |
“The HYBACS upgrade at Tubli alleviates the current overloading problem without the requirement for green-field construction, thereby utilising the existing secondary treatment assets whilst avoiding additional land take. Early results demonstrate that the plant is operating exceptionally well and meeting the highest standards, with an overall improvement in Nitrogen removal of 80%”.
Bahrain’s Ministry of Works Tweet



