The Salsigne mines have been active for almost a century, using on site refinery methods that are condemned now for polluting the environment.
You'll have basically 3 types of pollution (according to my geo-friend)
- a pollution that occurs in a circle of about 3 miles around the site. Mainly consisting of particles in the upper soils, coming from the smoke of the refining process and dust being moved from the waste tips by the wind. Moving away from the site normally means that the pollution is getting lesser.
- underground water streams getting into the water table from which water companies and people with their own water source draw their water from. The Orbiel river is an important source for this so it is vulnarable. As the pumping off of the waters in the mine shafts were stopped in 2004, water levels in the mines are rising and affecting the water table in the area. The region consist mainly of what is known as "karst", a porous chalc material, which lets these subterranean waters move around easily. Water-companies are controlling the levels of pollutants, including arsenic, and they won't let unsafe water pass to your house. So unless you've got your own well there's no problem here.
- The river Orbiel and its affluents have been contaminated heavily over the years. These pollutions are now mixed and for the largest part confined into the sediments in the river beds. On the occasion of larger disturbances of the riverbeds due to heavy rainfalls etc. these sediments will be uprooted, mix with the water and contaminate the area that was touched by the resulting high waters. So if you're house is likely to be touched by flooding of the river, then don't eat your home-grown veggies and keep your kids inside. Instances of poisoning of humans and cattle occurred during these circumstances.
Furthermore the local authorities are taking samples every week on 8 different points along the riverbeds to keep track of the pollution.
So, yes, mining "old-style" has polluted the area, even causing dead cows and the like. But you have also take into account the hysteria the word arsenic causes and the ongoing battle to install a waste dump on the former mining site, something that doesn't please all the inhabitants of the region....