The sprawling Avadi municipality covering an area of 64 sqkm would now have an underground sewerage system. Chennai Metrowater is preparing a detailed report for the Rs.125 crore-project. The details were discussed at a review meeting on comprehensive sewerage and water supply scheme being implemented in different phases in the adjacent urban local bodies in the Chennai Metropolitan area on Saturday. Sites have been identified for constructing 16 pumping stations. The sites identified for the pumping stations would be fenced.