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CDPHE Groundwater Standards <br />As a secondary resort, CDPHE groundwater standards were also used to determine limitations. The groundwater <br />standards were taken from CDPHE Regulation Number 41: Basic Standards for Groundwater [2]. In these basic <br />standards, groundwater is classified into five different categories. These categories are: <br />1. Domestic Use — Quality <br />2. Agricultural Use — Quality <br />3. Surface Water Quality Protection <br />4. Potentially Usable Quality <br />5. Limited Use and Quality <br />To classify the groundwater in the wells on the Revenue Mine site, the identification criteria explained in <br />Regulation Number 41 was used. First, Limited Use was removed as an option because the total dissolved solid <br />content of the well samples were under the qualifying level of 10,000 mg/L. Secondly, as the surface water <br />standards have already been taken into account, Surface Water Quality Protection was removed as an option. This <br />leaves three remaining options: domestic use, agricultural use, or potentially usable quality. As Potentially Usable <br />Quality is only applicable when no other option relates, an in -depth analysis was done to determine whether the <br />groundwater in question is classified as domestic or agricultural use. <br />CDPHE Domestic Use Groundwater Standards <br />Under Regulation Number 41 Section 41.4 -B -1, the criteria to classify water as domestic use are outlined. To be <br />classified for domestic use or domestic use quality, one or more of the following must be met within the specified <br />area: ground water is used for domestic use, there is reasonable potential for future domestic use of groundwater, <br />groundwater is permitted or decreed for domestic use by the State Engineer or applicable water court, and /or <br />background levels are generally adequate to meet the CDPHE human health standards. <br />Ground water is not currently used for domestic use within the Revenue Mine area and is not anticipated to be <br />used as such. The mine gets potable water from a nearby spring in which the water is pristine. The quality and <br />higher altitude of this water source indicates that it is in no way connected to the groundwater taken from the <br />sampling wells. <br />The nearest populated area to the Revenue Mine is the City of Ouray. The city currently obtains its domestic use <br />water from a nearby spring, the Weehawken Spring [3]. This water is considered pristine and requires minimal <br />treatment, according to an Ouray public works representative. The city services approximately 615 acres with this <br />treated water spanning the entire city as well as three subdivisions outside of the city limits [3]. A map showing <br />the water system in the City of Ouray can be found in Appendix F. There is also a subdivision located outside the <br />city that is provided with raw water from Weehawken Spring to be treated and distributed on site. The pristine <br />quality of the Weehawken Spring as well as the large distance between the spring and the Revenue Mine site <br />indicate that the groundwater under the site is not currently being used for domestic use. <br />It is not probable that the groundwater in the Revenue Mine area will be used for domestic use in the future. This <br />is because there is not demand for it from the City of Ouray. The City of Ouray is expected to have a 2.3 percent <br />12 <br />