Build modern refining plant.
Upgrade environmental mining standards.
Open mine with lower quality ore elsewhere.
Open high quality mine on disputed possible First Nations' land.
Invest in newer acidic mine waste neutralizing precautions.
Increase dividend for stockholders to attract investors.
Take no action.
Introduce new pension plan to sooth workers.
Invest more in nickel mining operations.
Invest more in zinc mining operations.
Improve ventilation and air quality testing.
Protect further against mine collapse.
Here's an interesting quiz for you.