AMBATOVY TAILINGS MANAGEMENT FACILITY WATER DISCHARGE

Excess process water is discharged from Ambatovy’s Tailings Management Facility (TMF) in order to balance the overall site water for the storage of tailings. This process water is pumped via a 12 km long, 900mm diameter HDPE onshore pipeline from the TMF to the 1.5 km ocean outfall pipeline by a barge mounted pumping system. PRDW was appointed to assess the current system and propose possible upgrades to increase the discharge flow capacity of the system from 4 600 m3/hr to 6 600 m3/hr.

A conceptual (FEL-1) study was carried out by PRDW to assess the existing system and to determine the most cost-effective option for increasing the capacity of the system, taking into account future re-locations of the floating barge pump station within the TMF system.

The recommend system upgrade option was to provide an additional barge pump station as well as two booster pump stations along the existing pipeline route.

PRDW, including a team of multi-disciplinary sub-consultants, was subsequently appointed for the pre-feasibility (FEL-2) study. This study included the following tasks:

• System hydraulics:
  • Steady state analysis
  • Transient analysis
• Control philosophy
• Basic engineering development:
  • New barge pump station
  • New booster pump stations (2 No.)
• Control and instrumentation requirements
• FEL-2 level cost estimate (-20 % to +30 %)
• High level risk assessment
• Implementation schedule

S2001/58