OREANDA-NEWS. August 16, 2007.  A subsidence, forecasted by the relevant expert after the flooding accident, occurred at the First Mine Division of Uralkali near the technical salt plant above a karst cavity. For safety reasons the access to the danger zone was immediately restricted. Furthermore, facilities in close proximity to the subsidence area, including the building of the technical salt plant, were closed down and partly dismantled.
At present, the situation in the subsidence area is being monitored in real-time mode and on 6th August, 2007, the rate of brine inflow into the mine was 3,400 cu/m an hour.

Arkady Krasnoshtein, Director, Mining Institute of the Ural Branch of the Russian Academy of Sciences:

"It should be noted that the subsidence has not caused any significant changes in the mine flooding process, with the brine inflow levels remaining within the forecasted value."
The initial size of the crater resulting from the subsidence was a 50x70 meter, with a depth of about 15 meter, less than previously forecasted. According to the international experts and scientists, the crater can gradually expand to the maximum radius of 220-250 meters. On August 8, its size was a 77x120 meters.

Uralkali management and scientists of the Mining Institute have decided to increase the subsidence monitoring by using special equipment: a video camera, an echo sounder, and a laser scanner.

The speed of surface subsidence within the Berezniki boundary has not increased as a result of the subsidence occurrence. In right-bank Berezniki, service line installations and house constructions are in progress in an effort to relocate people residing in the carnallite zone. This zone was developed in the late 1940s and early 1950s without carrying out any stowing operations. The flooding of this area may cause cracks in the buildings due to an irregular surface subsidence. The date for relocation of residents from the potentially dangerous zone, as scheduled by Rostekhnadzor (Federal Service for Ecological, Technological, and Nuclear Supervision) experts and scientists is set for December 1st, and has not changed.

From July 28 to August 2nd, according to the monitoring data, the surface settlement levels in the federal railroad area, located 168 meters away from the subsidence zone, were 1-6 millimeters. According to the subsequent daily observations, no increase in the rate of surface settlement was identified in the railroad area and transport operations are proceeding as usual. In the event of any slightest impending danger, a bypass line (previously constructed along the mine pillar boundary and located at maximum distance from the subsidence center) would be used for train traffic.

No surface settlement has been registered either in the area of other facilities located near the subsidence zone (beneath the industrial canal dam and the local combined heat and power plant (CHPP)). The CHPP gas pipeline was removed from the danger zone as early as November 2006. At present, the crater developments pose no danger to normal operations of the city's vital infrastructure facilities.

Vladislav Baumgertner, General Director, Uralkali:
"The scientists had forecasted the subsidence; therefore, the situation was no "surprise". The technical salt plant, located in the danger zone, was promptly closed down and, since January 1, 2007, all the employees have worked at other Uralkali divisions. Its possible destruction will not affect the implementation of the annual production plan. Other Uralkali production facilities are out of danger as they are located at a safe distance, in the mine pillar area."