Map showing the Sub-catchments for the Malabar Wastewater Treatment Plant
The Malabar Wastewater Project is located in the Malabar catchment which covers an area of approximately 27 km2 including the Borough of Arima and environs. At present, approximately 29% of the total population equivalent of the Malabar catchment has access to sewerage facilities, the majority of the existing sewerage systems (Arima WWTP, Malabar WWTP, Greenvale WWTP and La Horquetta Lift Station) are either abandoned or in a dire need of repair. The Malabar catchment is considered priority for development largely because the catchments drain into the Caroni River, upstream of the Caroni Water Treatment Plant, providing a portable water supply for 67% of the population. The treated effluent from the Malabar WWTP is expected to exceed water quality standards (EMA’s Water Pollution Rules 2001 amended 2006) and will be discharged into a creek which drains into the Mausica, then Caroni Rivers. The overall project comprises:
- Construction of a new 40 ML/d Wastewater Treatment Plant to meet the needs of year 2035 forecasted population of 108,630.
The new wastewater treatment plant (WWTP) will replace the existing Malabar WWTP, Arima WWTP, and several smaller plants previously installed by residential housing developers. The new plant will be located south of the Churchill Roosevelt Highway and just east of Peytonville in a green field site.
Construction sequencing will ensure that treatment of wastewater continues at existing facilities throughout construction of the new WWTP. The WWTP will be sized to treat the year 2035 design flow expectations. The influent pump station and screenings and grit removal facilities (headworks) will be capable of handling the design peak wet weather flow (PWWF) of 189 ML/d. The plant will also be sized to treat an average flow of 40ML/d and peak flow of 110 ML/d through secondary treatment. Flows which exceed the PWWF flow that cannot be treated immediately through secondary treatment will be stored in a storm water storage tank until secondary treatment capacity is available. Treated effluent will be discharged to a creek located south of the proposed site, which eventually drains into the Mausica and then Caroni River. Waste solids from the activated sludge secondary treatment process will be dewatered, solar dried and stabilized in green houses. After drying it will be hauled offsite and disposed at landfills.
The treatment scheme for the wastewater includes the following unit processes:
- Influent Pumping
- Septage Receiving Station
- Fine Screening
- Grit Removal
- Storm Water Storage
- Activated Sludge Aeration (Bioreactors)
- Secondary Clarification
- Return Activated Sludge (RAS) Pumping
The treatment scheme for waste solids from the activated sludge system includes the following unit processes:
- Waste Activated Sludge (WAS) Pumping ;
- WAS Dewatering (Gravity Belt Thickener and Belt Filter Press); and
- Solar Drying