This action is to support a field reconnaissance of the devastating landfill failure (wasteslide) on 10 July 2000 at the Payatas Landfill in Quezon City, Philippines. This landfill was reported to have been as high as a 7-story building prior to the failure. This failure resulted in extensive loss of life and injuries. Initial reports indicated that the failure was very fast (such as a debris flow) and triggered by heavy rainfall during the Typhoon Kai-Tak.
This failure is important because other documented landfill failures have been primarily along interfaces (Kettleman Hills) or caused by foundation failure (Beriolis, Spain and the 1996 Rumpke, Cincinnati waste failure). The Dona Juana Columbia failure was due to improper (pressurized) leachate recirculation, and little is known about a 1987 landfill failure in Turkey. To date, there is not a well-documented case of a failure of a landfill through the waste. If this were the failure mode, it would be important since the back-calculated strengths would provide data on the static strength of municipal solid waste landfills and on the impact of excess pore pressure on waste shear strength. As leachate recirculation and bio-reactor technology move from a few isolated test cells to widespread use in US landfills, and as urban development encroaches on existing landfills, characterization of the mechanical behavior of municipal solid waste and the impact of excess pore water pressures on shear strength becomes increasingly important.
The US reconnaissance team is travelling to Quezon City for field reconnaissance of the failure site. This investigation is being coordinated in the Philippines with a team of engineers from the University of Philippines - Diliman (UPD). Data being gathered by the combined group includes: pre- and post-failure geometry, slide plane identification, subsurface conditions, waste type and consistency, method of compaction, rainfall records, and other information that will allow an effective stress analysis of the failure to be performed. Identification of the pore pressures is a major challenge in the analyses. One important finding will be to assess the relevance of this failure to US practice.
The US reconnaissance team will provide full documentation of the failure, including geology, geometry, waste and compaction type, and weather conditions. The report will be broadly disseminated via hard copy and the Internet. Form 7: CMS-0092700; Scott M. Merry, U. of Arizona
This action is for a SGER award, and is therefore exempt from peer review. The support of post-failure reconnaissance teams to recover ephemeral data requires urgency consistent with the SGER criteria.
This action is a further step in the ongoing effort to obtain full-scale data from major damaging events such as earthquakes and tsunamis. But while NSF has provided support for many post-earthquake and post-tsunami reconnaissance teams, this is the first support that I am aware of for a post-landfill failure reconnaissance.
The PI contacted me shortly after this landfill failure in the Philippines to discuss a possible NSF-supported reconnaissance investigation. He also received input from the NSF Division of International programs. Given that events such as this landfill failure in the Philippines can be regarded as full-scale experiments that cannot be duplicated via controlled experiments in the laboratory or in the field, the cost of recovering and disseminating data obtained by reconnaissance efforts is minuscule compared to the cost of computer, laboratory or field simulations. It is essential that these reconnaissance efforts be supported.
It is recommended that this SGER request for support be approved.
