VANCOUVER (miningweekly.com) – TSX-V-listed tin project developer Strongbow Exploration has completed water treatment trials at its South Crofty project, in Cornwall, in the UK, and is now working on an application to the UK Environment Agency (EA) for a mine waste permit.

The company has hired global engineering and project management consultancy WS Atkins to submit an application to the EA for a mine waste permit with water discharge consent. The application is expected to be filed within a month and permits are likely to be issued before the end of summer this year.

Once Strongbow receives a mine waste permit with water discharge consent, the South Crofty project will be fully permitted, with a mining licence valid to 2071; planning permission to construct new surface process facilities; and the ability to dewater the mine.

"This is an important step forward as Strongbow works to bring the South Crofty mine back into operation. The South Crofty team worked closely with the EA throughout the process and I am very pleased that we were able to develop a system to treat the mine water which met their very high standards. We have resounding local support in Cornwall and I look forward to updating shareholders and the local community during the summer," president and CEO Richard Williams said in a press release on Thursday.

The water treatment trials were required by the EA to demonstrate that contaminated mine water could be treated, and dissolved metals and suspended solids collected before discharging mine water from the South Crofty mine workings into the Red river. The results of the trial successfully met all treated water target contaminant levels proposed by the EA.

A February preliminary economic assessment (PEA) on the South Crofty project has calculated a net present value, at a 5% discount rate, of $130.5-million, and an internal rate of return of 23.4%, at assumed metal prices of $10/lb tin, $2.65/lb copper and $0.90/lb zinc.

South Crofty has estimated pre-production capital cost, including contingency, of $118.7-million, with payback of 3.8 years and sustaining capital costs of $83.8-million over the eight-year life of mine.

The mineralised material mined in the PEA is 2.58-million tonnes containing 88-million pounds of tin equivalent, at an average grade of 1.55%.