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criteria that have been established to protect the public against consumption of drinking water
contaminants that present a risk to human health. Secondary standards are not enforceable
standards; they have been established for aesthetic qualities of water, such as taste, color,
and other. Contaminants with a secondary MCL are not considered to present a risk to human
health at the established maximum level. Notification levels (NL) are not enforceable
standards; however, they require that municipal water suppliers notify the public if the NL for a
chemical has been exceeded.
A total of 2,301 water quality results were extracted from the CDPH database for the 21
production wells in the Beaumont Basin. Results were obtained for 176 analytes sampled
between 2011 and 2015. The results of the analysis indicate that not a single production well
exceeds either the primary or secondary federal and state standards during the reporting
period. However, the California Notification Limit for Vanadium (100 ug/day) was exceeded
once at SMWC Well No. 4 during the reporting period.
Additional water quality information from 2009 through 2014 was obtained from Dudek
Engineering as part of the Maximum Benefit Monitoring Program. A total of 2,679 water
quality results were analyzed to determine if the water quality at the monitoring wells exceeded
drinking water standards. Drinking standards were exceeded for a limited number of
constituents as follows:
Nitrate-N – Eight of the 17 monitoring wells sampled for Nitrate-N exceeded the federal
and state primary MCL of 10 mg/L – Total of 52 readings. All of these wells are located
outside the Beaumont Basin.
pH – Nine of the 16 monitoring wells sampled for pH exceeded the secondary federal
MCL of 8.5 – Total of 22 readings. One of these wells is located in the Beaumont
Basin.
Total Dissolved Solids – Eight of the 16 monitoring wells exceeded the federal and
state secondary MCL of 500 mg/L – Total of 49 readings. These wells are located
outside the Beaumont Basin.
Turbidity – Eight of the monitoring wells sampled for turbidity exceeded the secondary
California MCL of 5 NTU – Total of 28 readings.
Appendix D contains summary statistics of the analytical results for the 2010-2015 period for
all chemicals that have a federal or state drinking water standard whether maximum
contaminant levels were exceeded.
4.2.1 Trace Metals
As indicated earlier, not a single domestic well exceeded either the primary or secondary
federal and state standards during the reporting period. This represents a significant
improvement over previous reporting periods when several wells exceeded the MCL for trace
metals. Trace metals are briefly discussed here and compared to previous reporting periods.
Aluminum. There were 33 water samples taken during the reporting period and tested for
aluminum. Aluminum concentration at all wells was below 50 ug/L, significantly below the
Beaumont Basin Watermaster 2015 Annual Report – Final – December 2016 4-6
