The report of the investigation pertaining to the oil layer found on the Diyawanna Lake has been handed over to the Minister of Environment.
The incident was reportedly the result of algae/bacteria growing, due to waste being disposed of in the Buthgamuwa canal over a long period of time, and the water flow of the canal being obstructed.
The report states the water may be enriched with Nitrogen and Phosphorus through garbage and waste water flowing into the canal through various routes.
The investigative team has called for the implementation of three recommendations to conserve water in the area.
Accordingly preventing non refined water from area residents and waste water from being let into the Diyawanna Lake, removing silt from the bottom of the Buthgamuwa canal at least once a year to allow an uninterrupted water flow and looking into whether waste water of the Ceylon Petroleum Corporation is being released to the water way has been recommended.