skip to the content of this page
AZ.gov Arizona's Official Website Arizona Department of Water Resources
Arizona Department of Water Resources AZ.gov Arizona's Official Web Site
Securing Arizona's Water Future
Water Quality in the Upper San Pedro Basin

Sites with parameter concentrations that have equaled or exceeded drinking water standard(s) (DWS), including location and parameter(s) are shown in Table 3.13-6A.  Impaired lakes and streams with site type, name, length of impaired stream reach, area of impaired lake, designated use standard and parameter(s) exceeded is shown in Table 3.13-6B.  Figure 3.13-10 shows the location of exceedences and impairment keyed to Table 3.13-6.  All community water systems are regulated under the Safe Drinking Water Act and treat water supplies to meet drinking water standards.  Not all parameters were measured at all sites; selective sampling for particular constituents is common.  A description of water quality data sources and methods is found in Volume 1, Appendix A.  Information on contamination sites in the basin is in Section 3.0.6 Water Supply - Contamination Sites.

Well, Mine or Spring sites that have equaled or exceeded drinking water standards (DWS)

  • Sixty-seven sites have parameter concentrations that have equaled or exceeded DWS. 

  • Frequently equaled or exceeded parameters include arsenic and fluoride. 

  • Other parameters commonly equaled or exceeded in the sites measured in this basin were cadmium, lead, nitrates, beryllium, mercury and total dissolved solids.

Lakes and Streams with impaired waters

  • Water quality standards were exceeded in three reaches of the San Pedro River.
  • The parameter exceeded was different for each reach; E. coli, nitrates and copper.
  • Two of the three impaired stream reaches, San Pedro River from the Mexican border to Charleston and from Babocomari to Dragoon Wash, are part of the ADEQ water quality improvement effort called the Total Maximum Daily Load  (TMDL) program.  Sampling to create a TMDL report is ongoing.

Effluent Dependent Reaches

  • There is one effluent dependent reach, Walnut Gulch, in the vicinity of Tombstone.

Click to view Table 3.13-6

Click to view Table 3.13-6 Water Quality Exceedences in the Upper San Pedro Basin

Click to view Figure 3.13-10

Click to view Figure 3.13-10 Upper San Pedro Basin

Water Quality Conditions

 

 

Arizona Water Atlas Home

Southeastern Arizona Planning Area Home

Download pdf of entire Southeastern Arizona Planning Area Download pdf of the Upper San Pedro Basin References and Supplemental Reading for the Upper San Pedro Basin
Colorado River Southeastern Arizona Planning Area

Download Southeastern Arizona Planning Area Atlas

Benson Narrows Gage Cascabel Road