Tailings are the finely ground rock left after flotation. The Combine stores them behind embankment dams at Sary-Bulak and Chatkal. Tailings from Soviet-era processing are held in the closed Chatkal Tailings Repository. This page sets out the main data of each facility.
| Item | Sary-Bulak tailings facility | Chatkal tailings facility | Chatkal Tailings Repository |
|---|---|---|---|
| Status | In operation | In operation | Closed in the 1990s |
| In use since | 1972 | 1996 | 1964 |
| Type | Valley dam, earth and rockfill, raised downstream | Lined pond beside the plant | Valley dam, earth embankment |
| Dam height | about 42 m | about 14 m | about 26 m |
| Tailings stored | about 11.8 million m³ | about 2.1 million m³ | about 6.4 million m³ |
| Responsibility | Sary-Bulak Antimony Works | Chatkal Chemical Smelting Complex | The Combine and the ISEZ Government, jointly |
| Last inspection | Chatkal Placer Mining Inspectorate, 24-09-2025 | Chatkal Placer Mining Inspectorate, 24-09-2025 | Chatkal Placer Mining Inspectorate, 24-09-2025 |
| Works | Pipeline replaced with pressure alarms, 2019 | Drainage collector cleaned, 2025 | Embankment raised and drainage installed, late 2000s |
Monitoring
Each dam is walked by the dam keeper every day and inspected by an engineer every month. Piezometers in the embankments are read every week, and every day during the snowmelt. Surface water and monitoring wells below each facility are sampled each month for antimony and arsenic, and weekly in April and May. Since 2018 the leases of the Sary-Bulak mines and the Chatkal complex have included tailings-safety conditions.
Emergency plan
Each facility has an emergency plan agreed with the Sary-Bulak District administration and the Ministry of Internal Security. Sirens below the Sary-Bulak dam warn Rudnik and Kara-Suu village, and the plan is exercised with the villages every autumn.
New tailings capacity
The Sary-Bulak facility has capacity for about nine more years at the present rate. Studies of a new tailings cell in the upper gorge were stopped in 2019 after objections from the herding families who use the pastures above the gorge. The Combine is studying the use of tailings as backfill in the mine instead.
See also Environment and the Environmental reports.