Gone are the days when a mining company could come in, set up shop, mine the ore and worry about land rehabilitation afterward. Now, companies must compensate and care for the surrounding land, air and water during the operational life of a mine. In fact, accountability is becoming more common-place since the requirement of a certified closure plan was proclaimed in 1991. Agrium takes its accountability seriously.

In 2002, Agrium’s ongoing geological exploration activities identified additional ore reserves that extend east and south of the original pit design. These ore reserves are located adjacent to and beneath Cargill Lake and in order to extract the ore from these reserves, the lake must be moved.

Agrium first proposed the lake relocation to Fisheries and Oceans Canada in March 2003.  The formal  application was submitted in July 2004. In December 2004, Agrium received approval under the Federal Fisheries Act for lake removal and replacement. Construction of the new lake began immediately thereafter.

Agrium worked closely with Calder Engineering Ltd. and Minnow Environmental Inc. to ensure the design of the new lake provided for all aspects of fish life stages. Extensive care and consideration was taken to  prepare the environmental report for the Ministries of Environment, Natural Resources, Northern Development and Mines, the federal Department of Fisheries and Oceans and local First Nations. Agrium invested much  front-end work by considering and addressing potential problems ahead of time. A series of community information sessions were held as well as a tour of the lake to familiarize stakeholders with the project.

The first construction phase in early 2005 involved constructing the new lake itself, removing organics (trees, bush, topsoil, etc.) and creating marginal areas. A natural depression in the topography assisted in the design for the new lake. Three water cells (ditches along the shoreline) were established where vegetation was transplanted to help establish the shoreline. A dam was constructed for containment.  As well, a fish ladder was constructed, similar in nature to an underwater flight of stairs, connecting the lake to the downstream creek. Fish habitat was built into the basin, providing for the various fish life stages. By spring, the new lake was close to full due to seasonal runoff and rainfall. During spring of 2006, Agrium also pumped water from Cargill Lake to the new lake, in order to restore the original water levels in Cargill.  This would facilitate fish transfer from Cargill to the new lake later in the summer.

On May 1, 2006, crews trolled along the shoreline, transplanting microscopic aquatic life and forage fish such as minnows. The forage fish would establish themselves in the new lake and provide a food base for the larger fish later in the summer. Following the three-month spawning period, transfer of the large bodied fish began and will occur in stages.

Aspects of the lake design provides an opportunity to improve the conditions of the existing wildlife as much as possible. The new lake will have a higher flushing rate, resulting in more dissolved oxygen, which is generally low in the northeastern Ontario lakes.. The former Cargill Lake tended to be an isolated lake due to a seasonal outflow of the downstream creek, allowing little fish movement. The fish ladder will allow greater movement of the fish between the downstream environment and the new lake. 

During its first summer (2006), the new lake has already hosted fish spawning, and has been frequented by other wildlife such as frogs, bears, moose, foxes and birds.

This lake is a temporary lake which, upon mine closure, will be replaced by a much larger lake within the pit area.  The new lake was therefore named Lake Pitama which is Cree for “for now”.