There has been an invasion of water hyacinth in the stagnant water of the Sabarmati this summer. Vast stretches of the river near Indira Bridge is covered by this invasive species.
Ahmedabad Municipal Corporation (AMC) engineering department officials said that factors such as availability of nutrients like phosphorus, nitrogen, the water surface temperature, salinity, pH, and lack of water are behind the sudden spread.
Concentration of total nitrogen was significantly higher, at 54.22 mg/l, than the prescribed norm of 10 mg/l.
Fecal coliform bacteria are found in human faeces and indicate sewage content.
The 106 MLD Pirana STP was also not meeting the prescribed norms for fecal coliform values, which exceeded 1,600 most probable number (MPN)/100ml).