English to Spanish Science Mining & Minerals / Gems Exploration

In making plans for mine plans, a few questions have come back that NN needs to think about and hopefully can respond:


1. Alluvial mining using mechanized equipment must be set back 50 meters from the water's edge. Will this be a problem on the location? I know there are some ways to limit this impact but we do not want to break the rules. I am thinking small excavators, loaders, dump trucks will be required .
2. Has NN ever hit bedrock while alluvial mining in the river or does he know how deep the gravels go? Or should we do either drilling, seismic, or ground penetrating radar? The last is the fastest and cheapest. One operator with the equipment, a geophysical tool, just walks over the area and it can profile to 30 meters depth.