For groundwater, baseline level refers to the specific levels of various substances found in the water before uranium recovery operations begin, typically expressed as parts per million (ppm) or a similar measurement.
WDEQ has a series of classifications for groundwater which specifies what the water can safely be used for. Each classification has its own limits on the concentration for different substances, and include (in descending order of quality) domestic, agricultural, livestock and industrial use classifications. By WDEQ standards, the aquifer within which the Ross ore body is located will likely be classified as not currently fit for human or livestock consumption, and will be considered industrial-use only due to high radionuclide concentrations (primarily radium).
Once mining operations have concluded, Strata will be required by license to restore the water quality in the mined aquifer to pre-operational water quality.
Taken literally, restoring to “baseline” means that each parameter measured must be restored at or below its respective baseline measurement. Therefore, if a single substance was measured at a baseline level of X ppm and is measured at X+1 ppm (or even X+0.0001 ppm) after restoration, the water is not considered restored to baseline even if all other parameters are at or below baseline. Given this definition, ISR operations have a record of restoring the majority of parameters (particularly the more concerning ones like arsenic, radium, cadmium and others) to or below baseline standards. In some cases, operations restored a number of parameters that had previously exceeded EPA standards to not only below baseline, but below the EPA standards; however, because some parameters remained above their baseline levels, these operations are not considered to have restored baseline levels.
Even if a particular analyte is not restored to its exact baseline level, it may still be restored to a level consistent with the original class of use. This means that while the water may have slightly different concentrations of substances, it can still safely be used for the same purposes it was prior to operations.
The aquifer in which the Ross ore body is located is already considered unsafe for consumption by humans and livestock, or for use in agriculture. Strata will make every effort to restore water to baseline conditions following uranium recovery operations, but even if the water is not restored to exact baseline conditions it will still be restored to levels within the original class of use.