Elevated phosphate, ammonia and total suspended solids near sewage outlets and reclamation sites in coastal waters of Makassar, Indonesia

Abstract

Makassar is a large city in Southeast Asia with a strategic role to play in supporting the development of Indonesia. Its position as a centre for local and regional development has led to a sharp increase in the human population and a concomitant need for supporting facilities. With limited land in coastal areas, reclamation is one option being implemented. The increases in population and reclamation have both had negative effects on the condition of coastal waters. This study aimed to compare the levels of phosphate, ammonia and TSS in the waters near selected drainage outlets of Makassar City before and after land reclamation. The results showed increasingly high levels of phosphate at two sites (Jongaya and Paotere Canals). Increased ammonia, nitrogen and TSS were only found at the outlet of the Jongaya Canal. Four of the outlets (Jeneberang River, Benteng Canal and Tallo River) had relatively low nutrient concentrations. The results indicate that domestic waste is a major source of phosphate and ammonia pollution in the Jongaya and Paotere Canals. In the Jongaya Canal, all parameters (phosphate, ammonia, nitrogen, and TSS) were higher after the reclamation than beforehand