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Agnico Eagle Kittilä Mine Provides an Update on Water Seepage Event

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Agnico Eagle’s Kittila mine today provided an update on the remediation work related to the water seepage from its holding pond (NP3).

Water seepage was first discovered on September 14th during a routine inspection of the dam.  The seepage was observed at the toe of NP3 dam and has since been identified to be occurring through the liner at the bottom of the holding pond.  The original flow rate was approximately 350 cubic meters per hour (m3/hr), however, the flow rate has been reduced to approximately 250 m3/hr by the deposition of moraine on the affected pond bottom.  Within 36 hours from first detecting the seepage on September 14th, discharge of seepage water to the environment had stopped as all water from the uncontrolled discharge was collected and pumped back in the holding pond or the water management system.

Water Quality Management

The water quality of the uncontrolled discharge met all applicable permit requirements and was of appropriate quality to be released to the environment.  This water is normally discharged to the environment or re-used as process water.  It is estimated that the uncontrolled discharge resulted in an exceedance of approximately 30% of the authorized discharge volume for the month of September.

Following detection of the seepage, the Lapland ELY Centre (Environmental Supervising Authority) was informed, monitoring of the quality of the river water was undertaken and an assessment of the impacts on the river was conducted by an external firm.  The study found that the river had not been impacted by the increase discharge of treated water.  Additional monitoring of the river has not shown any significant effect on the river.

A remediation plan was presented to the Lapland ELY Centre and the Kainuu Ely Centre (Dam Safety Authority) which included sealing of the seepage area in the pond with moraine.  Moraine deposition started but has since been stopped until the water level in the pond can be reduced sufficiently for the safe operation of equipment.  To reduce the water level, the Kittila mine made a request to the Authorities for a special permit to discharge additional volume of water within the authorized water quality requirements for a period of 5 weeks from the end of October to the end of November.  The request was approved and the additional discharge began on October 23rd.

In parallel, the Kittilä mine has begun transferring water from NP3 to a new water storage reservoir that was completed in the fall of 2015.  Approval from the Authorities was received on October 30th to allow commissioning of the water reservoir and water transfer began immediately. The transfer of water from NP3 to the new water storage reservoir will help reduce the water level in NP3 and allow mitigation work on NP3 to proceed safely.

Remediation Actions

Agnico Eagle initiated remediation actions immediately after the seepage was discovered on September 14th. These actions included: 

  • A dike was constructed in the collecting ditch at the toe of NP3 to collect all the seepage water and to stop the uncontrolled discharge to the infiltration field.  Pumps were installed behind the dike to pump all the water back.  Complete control was achieved on September 16th, within 36 hours of the seepage detection;
  • Divers were used to inspect the pond in an attempt to locate the source of seepage;
  • Moraine was deposited in the area of the pond where seepage was detected, resulting in a reduction of approximately 30% in the seepage rate within days;
  • Investigation and characterization work was carried out to identify the source of seepage and the possible impacts to the river;
  • The deposition of moraine was temporarily halted until the pond level has been sufficiently reduced to allow safe operation of equipment.  A water level reduction of approximately 3.5 metres will allow access to a rock ramp that will serve as a base for the equipment to resume moraine deposition; and
  • A pumping station has been installed to continue pumping water back to the pond for as long as seepage continues.

A detailed action plan for a permanent solution is being developed by a team of internal and external experts.

It is important to point out that at no time has the structural integrity of the dam been at risk.  Agnico Eagle has been in regular contact with the engineering designer of the dam and the Authorities since discovering the seepage on September 14th.  In addition, a formal inspection of the dam was conducted in July 2015 by an external third-party and the inspection did not identify any noticeable source of seepage. 

Agnico Eagle continues to work closely with the Authorities on monitoring the situation and to implement a permanent solution.

The Kittilä mine currently employs approximately 600 permanent employees and contractor workers.

For additional information, please contact:

Mr. Ingmar Haga, Vice President, Europe, Agnico Eagle, tel. +358 40 700 3518, email: ingmar.haga@agnicoeagle.com


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