The California State Water Resources Control Board by Resolution 92-49 adopted a policy that an area of contaminated groundwater where cleanup cannot be achieved may be designated a Containment Zone. To date no mine in the state has been designated a containment zone, but such a designation would bring clarity and closure to many of the vexing and contentious issue surrounding mine closure in California. This is why.

Consider a mine where you would expect it: in a zone of mineralization. The same natural conditions that lead to formation of the ore body are why pre-mining background water quality exceeds local groundwater quality standards. During mining the pit draws down the site’s water table and waste rock dumps and tailings impoundments change the inflow and recharge over large areas. The result is a change of groundwater flow patterns and constituent distribution. Application of standard regulations would indicate the need to “cleanup” the site by:

  • Removing the source, i.e., the waste rock or tailings piles; and/or
  • Control discharge by building covers over waste units; and/or
  • Remove pollutants from the “contaminated” groundwater by pump & treat; and/or
  • Get an NPDES permit and meet its limits by treating surface water if necessary.

Now assume that cost-effective & technically-practical covers are in place, that nobody would ever let you move rock or tailings from the site, that the wetlands result in NPDES compliance, and natural geology prevents off-site migration of the groundwater that is affected as much by the natural geology as by mining. Assume that you pump and treat to deal with the small part of the groundwater pollution that is from mining; nothing happens—there is no improvement of groundwater quality; and your consultant tells you that natural conditions swamp any improvement potentially wrought by pump & treat. To avoid the claws of the bring-a-suite lawyers and to eliminate the monthly meetings in Sacramento, what law do you seek to have applied?

Right now there is none that I know of—if you know please tell me. The containment zone policy was not truly designed for the mining situation I postulate. Rather it was designed and has been applied to the following case which is quaintly described on the internet:
South Bay site where a PRP built an adequate pump and treat system, operated it for years at significant expense, demonstrated decreasing mass removal that reached an asymptotic level for several years, turned off the system (with RWQCB permission) and demonstrated no change in contaminant levels (i.e. it did not increase), is required to continue monitoring, would have to turn the P&T on again if the plume threatens to migrate offsite (it’s still beneath the PRPs property), no drinking water source is threatened.

But maybe, just maybe, the Containment Zone policy—or at least the fundamentals of its approach—should be applied or be applicable to my postulated mine. There is nothing further that can be done to eliminate the source, it is not possible to stop discharges from the waste piles, groundwater pollutants will never be reduced or eliminated by pumping and treating (you cannot fight the whole of nature) and neither groundwater nor surface water leaving the site changes downgradient receiving waters. Why not call this a Containment Zone and bring closure, finality, and certainty to a site which is what it is and which never can be made significantly different. Sure it is polluted in common parlance, but then the job of laws is to make it possible for societies to function sanely and effectively for the benefit of its citizens in the face of nature’s vicissitudes. We do not live in a Platonic republic but rather in one beset by planes, bombs, hurricanes, nature’s caprice, and a desire for the material goods resulting from mining.

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