Page 100 - Beaumont Basin Watermaster - DRAFT 2016 Annual Report

Appendix D contains summary statistics of the analytical results for the 2012-2016 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 42 water samples taken during the reporting period and tested for
aluminum. Aluminum concentration at all wells was below 50 ug/L, significantly below the
secondary MCL of 200 ug/L. Aluminum above the MCL can add color to water. One well
exceeded the MCL during the FY 2004-08 reporting period.

Arsenic. There were 43 water samples collected and tested for arsenic during the reporting
period. The highest arsenic concentration was observed at SMWC’s Well No. 4; arsenic
concentration at this well has increased from 4.2 mg/L in 2009, to 4.6 mg/L in 2012, to the
highest value of 5.2 mg/L in April 2013. Latest value, recorded in April 2016, arsenic
concentration was down to 4.4 mg/L. One well exceeded the MCL during the FY 2004-08
reporting period.

Iron. A total of 42 water samples were taken during the reporting period and tested for iron. In
most cases iron concentration was below 100 ug/L., which is significantly below the current
secondary MCL of 300 ug/L. However, there is one well that exceeded the MCL during the 2012-
16 period; BCVWD Well No. 3 at 450 mg/L. Iron at a concentration above the MCL can impact
color, odor, and taste in water. Five wells exceeded the MCL during the FY 2004-08 reporting
period.

Lead. There were 42 water samples collected and tested for lead during the reporting period. The
highest concentration reported were 0.0065 mg/L at BCVWD Well No. 25 and 0.0058 mg/L at
Rancho Calimesa Mobile Home Park Well No. 1. Both of these concentrations are significantly
below the current primary MCL for Lead of 0.015 mg/L. Lead concentrations in water above the
MCL can have significant impacts on human health. One well exceeded the MCL during the FY
2004-08 reporting period.

Manganese. There were 42 water samples taken during the reporting period and tested for
Manganese. Manganese concentration at all wells was below 20 ug/L, significantly below the
secondary MCL of 50 ug/L. Manganese can significantly impact color and taste in water at
concentrations above the MCL. One monitoring well exceeded the MCL during the FY 2004-
08 reporting period.

Total Chromium. A total of 42 water samples were taken during the reporting period and tested
for total chromium. The highest reported concentrations of total chromium were observed in
January 2012 at Banning C-02A at 17 ug/L and in March 2014 at Banning C-3 at 14 ug/L. Both of
these values are significantly below the current state primary MCL of 50 ug/L. One well exceeded
the state primary MCL during the FY 2004-08 reporting period.

Beaumont Basin Watermaster 2016 Annual Report – DRAFT – August 2017 4-8