We work to achieve good environmental leadership and decision making at all levels so that we can deliver the environment that Lagosians expect and deserve.
On this website you can find out about issues that affect the environment, environmental laws and treaties and environmental reporting.
Sewage Process Flow, Ministry of the Environment, Lagos State
Pre-treatment
Pre-treatment removes materials that can be easily collected from the raw wastewater before they damage or clog the pumps and skimmers of primary treatment clarifiers (trash, tree limbs, leaves, etc).
Screening
The influent sewage water is strained to remove all large objects carried in the sewage stream. This is most commonly done with an automated mechanically raked bar screen in modern plants serving large populations, whilst in smaller or less modern plants a manually cleaned screen may be used. The raking action of a mechanical bar screen is typically paced according to the accumulation on the bar screens and/or flow rate. The solids are collected and later disposed in a landfill or incinerated.
Grit removal
Pre-treatment may include a sand or grit channel or chamber where the velocity of the incoming wastewater is carefully controlled to allow sand, grit and stones to settle.
An empty sedimentation tank at the Oke-Afa Sewage Treatment Plant
