A preliminary investigation of options of remediation of a coastal landfill in the Maldives
Authors: Brown, S., Stringfellow, A., Beaven, R., Nicholls, R.J. and Murthaza, A.
Conference: 16th International Waste Management and Landfill Symposium
Dates: 2-6 October 2017Abstract:
The 3.5 hectare Addu dump site is located in the far south of the Maldives on a narrow strip of land between the atoll islands of Hithadhoo and Maradhoo, located approximately 1.5m above mean sea-level. The site is unlined and there is no engineering to protect the underlying coral sands. The site, opened in 2004, contains approximately 75,000 tonnes of predominantly household wastes, which has been dumped in two windrows without the use of any daily cover. Analysis of samples taken from ponds adjacent to the waste showed elevated EC and chloride concentrations suggesting seawater intrusion was affecting groundwater. Ammonia concentrations were low and nitrate was present in the groundwater samples. The lack of compaction of the waste may allow air ingress so that aerobic biodegradation predominates. Coastal erosion is not currently a problem at the site. Sea water intrusion appears to force groundwater close to the base of dumped waste, and creates some flooding across the site during spring tides. The potential for flooding and rising groundwater levels is likely to increase with sea-level rise (with global projections up to 0.98m by 2100). Options for reclamation of the site could involve separation of metals and inert material, and the remaining material sent to the proposed EfW plant, although further work is needed to understand the suitability of this material for incineration.