Odaw River and Korle Lagoon

The Odaw River flows through Accra and empties into Korle Lagoon, one of the most polluted urban water bodies in West Africa. Sampling took place in Alajo, a densely populated part of Accra, on January 26, 2025, drawing from a heavily polluted gutter that feeds into the lagoon.

Why this site

Prior research on the Odaw had already flagged serious concerns: antibiotic resistant E.coli at levels far exceeding WHO safety guidelines, heavy fecal contamination affecting communities that rely on the river for drinking water, and a broader ecological decline downstream tied to worsening pollution and waste management failures. This made it a strong test case for urban, sewage driven contamination rather than industrial or mining pollution.

Method and results

Lab analysis, run across multiple dose levels (10ml and 25ml), showed turbidity dropping from 52.6 to 3.43, inside the WHO guideline of 5. Suspended solids fell from 60mg/l to 5mg/l. All solids, E.coli, legionella and waterborne viruses were removed, and the water's visual state moved from a darkened, murky brown to clear and fresh. A couple of secondary parameters, like TDS or pH, sat slightly outside guideline at certain dose levels, but the core contamination markers were resolved well within safe limits.