Landslide of construction debris buries town, kills dozens

By ThinkReliability Staff

Shenzhen, China has been growing fast. After a dump site closed in 2013, construction debris from the rapid expansion was being dumped everywhere. In an effort to contain the waste, a former rock quarry was converted to a dump site. Waste at the site reached 100 meters high, despite environmental assessments warning about the potential for erosion. On December 20, 2015, the worries of residents, construction workers and truckers came true when the debris slipped from the quarry, covering 380,000 square meters (or about 60 football fields) with thick soil as much as 4 stories high.

A Cause Map can be built to analyze this issue. One of the steps in the Cause Mapping process is to determine how the issue impacted the overall goals. In this case, the landslide severely impacted multiple goals. Primarily, the safety goal was impacted due to a significant number of deaths. 58 have been confirmed dead, and at least 25 are missing. The environmental goal and customer service goal were impacted due to the significant area covered by construction waste. The regulatory goal is impacted because 11 have been detained as part of an ongoing criminal investigation. The property goal is impacted by the 33 buildings that were destroyed. The labor goal is also impacted, as are more than 10,600 people participating in the rescue effort.

The Cause Map is built by visually laying out the cause-and-effect relationships that contributed to the landslide. Beginning with the impacted goals and asking “Why” questions develops the cause-and-effect relationships. The deaths and missing persons resulted from being buried in construction waste. Additionally, the confusion over the number of missing results from the many unregistered migrants in the rapidly growing area. The area was buried in construction waste when waste spread over a significant area, due to the landslide.

The landslide resulted from soil and debris that was piled 100 meters high, and unstable ground in a quarry. The quarry was repurposed as a waste dump in order to corral waste, which had previously been dumped anywhere after the closure of another dump. Waste and debris was piled so high because of the significant construction debris in the area. There was heavy construction in the area because of the rapid growth, resulting in a lot of debris. Incentives (dumpsite operators make money on each load dumped) encourage a high amount of waste dumping. Illegal dumping also adds to the total.

While an environmental impact report warned of potential erosion, and the workers and truck drivers at the dump registered concerns about the volume of waste, these warnings weren’t heeded. Experts point to multiple recent industrial accidents in China (such as the warehouse fire/ explosion in Tianjin in August, the subject of a previous blog) as evidence of the generally lax enforcement of regulations. Heavy rains contributed to ground instability, as did the height of the debris, and the use of the site as a quarry prior to being a waste dump.

Actions taken in other cities in similar circumstances include charging more for dumping debris in an effort to encourage the reuse of materials and monitoring dump trucks with GPS to minimize illegal dumping. These actions weren’t implemented in Shenzhen prior to the landslide, but this accident may prompt their implementation in the future. Before any of that can happen, Shenzhen has a long way to go cleaning up the construction debris covering the city.