This birds live and nest in the tundra; not a place short of acid soils and acid water. Again, why they don't dissolve resting all day in permafrost mud?
So maybe they should consider a different explanation? Lack of food in tired migrant birds?, because nothing grows in that waters... plus poisons in water. Lead maybe?. Keep shooting.
Birds remaining too much time in the water could be solved providing a few artificial islands in the center. Even building a second pond with healthy water a few thousand meters away would be more simple and even cheaper that shooting at birds all the time for years (after all they have a lot of digging machines available yet). Smaller pool with food or big pool without any food? Does not seem like a difficult choice. Give them protection and food and will say goodbye in a heartbeat.
More simple but less funny, of course. Apart of that, the number of man-hours spent on this looks like a total waste.
And putting chalk in the water would fix it and should be doable, because you just need to reach safe tundra levels, that are very acidic yet. Chalk is relatively cheap. Why is that "too expensive" for the company?. Better kill the animals instead to do something really useful?.