By Cynthia Pryor

The main and substantive issue, in the new Air Quality permit application for the Rio Tinto Eagle Mine, is Rio Tinto’s assertions that an air emission control is not required for the Main Air Raise Vent (MVAR). The MVAR is a stack that is 128″ (10.6′) in diameter and 65′ high and is the only vent for all the underground workings for the mine. The emissions will include all those items associated with the development and retrieval of the ore body including blasting, ore handling, truck traffic, diesel fuels, large mine heaters, etc. Rio’s original Air Quality Permit was approved with the inclusion of a Bag House and air filter on this MVAR stack – that would capture 99% of all emissions which would include reactive sulfides resident in and broken loose from this ultramafic massive sulfide ore body.

Rio Tinto has reconfigured their plant so that they have moved the original underground cement batch plant and associated material silos (aggregate, cement) to the surface near Eagle Rock. They say there will be no crushing underground and an ore pass system will not be utilized – therefore reducing sulfide dust and emissions to such a low level that a bag house would no longer be required. In fact they say that a bag house would not even function properly – the emissions are so low. They will instead control all underground dust with water spray from a tank truck and and a hose.

All of Rio’s assumptions are based on modeling programs, heater systems whose emissions are exempt from regulation, and the assertion that will be able to control all dust with water spray from a hose. The DEQ does not require them to have controls on this huge MVAR stack, even though there will be controls on every other emission source at the mine, including an emergency generator. The DEQ does not require any air quality monitoring of the site or of this stack. Emission testing of the stack will only take place when Rio Tinto is producing 1,660 tons of ore a day. The DEQ will not require any emission testing during the blasting of adits or production of ore under this tonnage rate. Sulfide, heavy metals, blasting emissions, fuel emissions, etc. will be free flowing into the air on the Yellow Dog Plains with no control, no monitoring, and very limited testing.

The DEQ calls the Yellow Dog Plains an attainment area – which is a geographic area which has air quality below Federal Air Quality Standards. In other words, the air is good on the Plains and Rio has now the ability, under law, to pollute this air until they reach the limit of the air quality standard set by the EPA. Their models show that they can do this at 91% of the attainment level. That leaves 9% left for someone else to pollute to get them at a Saginaw, Detroit Chicago level of Air Quality. These emissions are only representative of the mine area itself. All diesel emmisons and fugitive dust from the transportation of the ore on public roads are not included in this emission standard calculation. The DEQ says they have no regulatory oversight of public roads. Nor do they have oversight of the underground workings to prove they can make their claims of low emissions. That is someone else who takes care of that (Mine Safety and Health – MSHA) . The DEQ is only concerned with what comes out of the stack and Rio’s models say they can do it and that is all the proof they need until they do their first production emissions test.

From the beginning, the State of Michigan has recognized that non-ferrous sulfide mining is different and that sulfides, from metallic sulfide mines, released into the environment and coming into contact with air and water can cause Acid Mine Drainage and damage to our land, our waters and our communities. The DEQ Air Quality staff do not seem to see any danger to the Salmon Trout River which flows a mere 150′ from this stack. They have required no impact assessment of the Yellow Dog watershed, nor an impact statement to Eagle Rock – the KBIC sacred site within the fence of this mine. They see no danger to the community of Big Bay and it’s peoples, lake and streams who are an immediate few miles downwind from the Eagle Mine.

Our job is to ask for proof that their models are correct – by demanding air quality monitors at the site that run 24/7 for the life of the mine.
We must also demand that Rio Tinto keep the promise that they made in their original permit (made as a result of public comment and pressure!) to put an air filter on the main polluting source at the site – the MVAR stack. “PROMISES KEPT” is Rio Tinto’s main motto. Let us make them hold to that promise.