Cucamonga Valley Water District Reopens Critical
Water Treatment Plant
IIn 1997 the Cucamonga Valley Water Dis-trict
(CVWD) constructed the 3.0 (MGD)
Arthur H. Bridge Water Treatment Plant
(AHBWTP) to treat water from Cucamon-ga
Canyon, a foothill canyon at the base of
Southern California’s San Gabriel Mountains.
Canyon water accounts for 10 percent of the
district’s supply and helps reduce reliance on
imported water for its almost 200,000 custom-ers.
In 2010, however, winter storms caused
significant damage to the canyon facilities,
including the treatment plant intake. This and
complications with the original membrane
filtration process caused the plant to be used
intermittently before it was shut down com-pletely
In 2013, recognizing the value of this local
resource, CVWD began to rehabilitate the in-take
facilities and replace the treatment tech-nology,
hiring HDR to work with the district
and its consultants and permitting agencies
on a design-build project that resulted in in-novative
solutions for both the canyon intake
and the AHBWTP treatment train. Challenges
to the project included:
• Remote operation of an unmanned and in-termittent
plant. AHBWTP is typically un-manned
and only operational when there
is sufficient flow in the canyon.
14 SOURCE winter 2015
• The previous membrane filtration process
was challenging to operate and maintain
and ultimately failed, in part due to the lon-ger
durations of shutdown that were typ-ical.
• The new process needed to be robust
and capable of frequent shutdowns while
also being low maintenance and with
near-complete remote operation.
• The existing space in the building was
limited and needed to house a completely
different process than it was originally in-tended
• The new process did not require breaking
head at the plant. The main process does
not require any pumping and operates sole-ly
off existing head from the canyon.
• The original intake was washed out, dam-aged
and had been replaced multiple times.
The previous design created a pond and
submerged intake that was easily damaged
from debris flows during heavy storms and
prone to seasonal algae blooms.
Given CVWD’s limited budget, there were
several innovative solutions that reused vari-ous
components of the existing plant, includ-ing
raw water conveyance pipeline and strain-ers,
disinfection facilities and underground
storage tanks, which were repurposed for
backwash equalization and solids storage, as
well as the building, electrical power distribu-tion
and other ancillary facilities.
The new canyon intake features a self-sus-taining
design that draws both surface wa-ter
and subterranean flows while allowing
storm-driven canyon debris to roll past with-out
impacting the intake’s performance. The
new intake also improves raw water quality by
eliminating the previously designed shallow
intake ponds that were prone to algae blooms
during certain times of the year.
Treatment Plant Innovations
Treatment plant upgrades provide a reliable
plant capacity of up to 3 MGD. Modifications
included replacing the existing membrane
equipment with a pressure filtration technol-ogy
from EPD USA, Inc. The dual-stage EPD
pressure filtration system uses a garnet sand
media and poly coagulant as a filter aid. The
system designed for AHBWTP consists of two
treatment trains with a total of 12 filter vessels
in the first stage, followed by 10 vessels in the
second stage. Each train has a maximum rat-ed
capacity of 1.5 MGD, and the design layout
By Gidti Ludesirishoti
Members of the water treatment plant project team, (l-r): Art Berry, EPD US, Eduardo Espinoza, CVWD, Larry Johnson, HDR Engineers, Tony Snead, HDR Construc-tors,
Gidti Ludesirishoti, HDR Engineers, Paul Berry, EPD USA, Ash Dhingra, AKD Consulting, Shay Lawrey, Jericho Systems, Rob Hills, CVWD, Gary Binger, HDR
Constructors, John Bosler, CVWD, Bruce Schuler, Schuler Engineering, Jennifer Land, HDR Constructors.
Continued on page 26