Page 75 - Beaumont Basin Watermaster - 2015 Annual Report
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conventional OSWDS. WEI further indicates that the Regional Board initiated a process in
2009 that may lead to amending the Basin Plan prohibiting conventional OSWDS and
regulating the discharges to meet antidegradation objectives.
Summary of University of California, Riverside Study
This study is titled: “Water Quality Assessment of the Beaumont Management Zone: Identifying
Sources of Groundwater Contamination Using Chemical and Isotopic Tracers” (UCR, 2012).
The study divides the BMZ into four distinct zones; their location is depicted in Figure 2 of the
UCR report (not included here). A brief description of the zones is as follows:
Zone 1 – Region Influenced by Wastewater Treatment Plant Effluent. This zone occupies the
southernmost area of the BMZ. Water quality in this zone is influenced by effluent from the
City of Beaumont wastewater treatment plant.
Zone 2 – Wildland and Low Density Septic Disposal Region. This zone is defined as the area
uphill of Edgar Canyon to the north of Cherry Valley. Water quality in this area had low to
moderate concentrations of TDS and nitrate.
Zone 3 – Urban Region with On-site Septic Disposal Systems. This zone overlies the Cherry
Valley area including the area around the Noble Creek and Little San Gorgonio Spreading
Ponds. Human waste from homes and business in this zone is primarily disposed of in on-site
waste disposal systems.
Zone 4 – Urban Region with Consolidate Sewer System. Zone 4 comprises those portions of the
City of Beaumont utilizing a municipal wastewater system.
The UCR report attempted to answer a series of questions; the questions and a summary of
their response is provided below.
1.- Can different groundwater regions within the BMZ be defined using isotope, PPCP, and
general chemical parameters?
According to the study,
Zone 1 was characterized by relatively high levels of PPCPs and it has the highest
likelihood for nitrate contamination from human waste.
Zone 2 had detectable levels of some PPCPs. Septic contributions to groundwater are
relatively minor.
Zone 3 had several wells with clear signs of contamination by septic systems.
Groundwater in the central portion of Cherry Valley appeared to be more strongly
affected by septic systems than on the periphery of Cherry Valley.
Zone 4 shows the fewest signs of human waste as most homes are served by
consolidated sewer systems.
Beaumont Basin Watermaster 2015 Annual Report – Final – December 2016 4-4
