The Mancos Shale and Elpedro soil dominate the surface of Rio Arriba County east of the Continental Divide.
Targeting the Mancos Shale and the Dakota Sandstone, thereunder, essentially risks four groundwater sources: surface, shallow well, non-tributory, and deep well.
Fracking Mancos Shale near the surface can geyser toxic fracking fluids, flowback, and produced water out of historical, uncased, shallow dug, seasonal water wells.
Fracking deeper into the Mancos Shale, and into the more likely target, the Dakota Sandstone, risks contamination of the drinking-water-bearing Morrison Formation (blue).