Fall 2013 - Carollo Engineers

Traci Brooks
Traci Brooks received
her B.A. in Physics from
Austin College and her
M.S. in Civil Engineering
from the University of
Colorado at Boulder. Her
graduate research looked at the degradation
of chlorine by UV radiation in the presence
of nitrates.
She joined Carollo’s Boise office as a
full-time employee in January 2012, after
completing a 2-month summer internship.
During her internship, she participated in
the validation of a Xylem-WEDECO K143
UV reactor. This testing was conducted
at flows up to 72 mgd, and was the largest
validation of its kind performed to date.
At Carollo, Traci has taken increasing
responsibility as the lead validation engineer
responsible for testing more than ten UV
reactors at Carollo’s Portland UV Validation
Facility. She also works on data analysis,
report writing, and reviewing for the
validation projects. Traci is looking forward
to being involved in other UV technology
projects with Carollo.
Varun Gandhi,
Ph.D.
Dr. Varun Gandhi
received his B.S.,
M.S., and Ph.D.
in Environmental
Engineering from the Georgia Institute
of Technology. His Ph.D. research was on
the hydrodynamics and dose delivery in a
lab-scale UV reactor using laser-induced
fluorescence. Using this technology, he has
also analyzed the dose delivery in an ozone
contactor and the flow characteristics of
dense brine disposal through multi-port and
rosette-shaped diffusers. He has authored
or co-authored 10 peer-reviewed and
conference papers related to various aspects
of water treatment.
While at Carollo, Varun has worked on
validation testing of multiple UV reactors
at Carollo’s Portland UV Validation Facility,
along with data analysis and report writing.
He has also developed CFD models of UV
reactors to compare treatment efficiency
and develop action spectra correction
factors for utilities around the U.S. In
addition, he has developed CFD models for
an ozone disinfection reactor.
Phoenix, Arizona
Yuma, Arizona
Fresno, California
Inland Empire, California
Los Angeles, California
Orange County, California
Pasadena, California
Sacramento, California
San Diego, California
San Francisco, California
Sunnyvale, California
Ventura County, California
Walnut Creek, California
Denver (Broomfield), Colorado
Denver (Littleton), Colorado
Broward County, Florida
Miami, Florida
Orlando, Florida
Palm Beach County, Florida
Sarasota, Florida
Boise, Idaho
Chicago, Illinois
Kansas City, Missouri
Omaha, Nebraska
Las Vegas, Nevada
Reno, Nevada
Oklahoma City, Oklahoma
Portland, Oregon
Austin, Texas
Dallas, Texas
Fort Worth, Texas
Houston, Texas
Salt Lake City, Utah
Seattle, Washington
Research SOLUTIONS
WHAT’SNEW
8
Carollo will offer a webcast through the
WateReuse Research Foundation (WRRF)
for WateReuse Project 11-10, Evaluation of
Risk Reduction Principles for Direct Potable
Reuse.
Carollo also offered a webcast on September
19th through the Water Research
Foundation (WaterRF) for WaterRF Project
3032, A Decision Tool for Earthy/Musty Taste
and Odor Control.
Date: November 14, 2-3 pm EST.
Value: The webcast will highlight Carollo’s
leading edge work in implementing direct
reuse. It will also explore the costs and
benefits to different risk management
alternatives for direct potable reuse and
its implications for the future of reclaimed
water use.
This webcast highlighted Carollo’s expertise
in taste and odor (T&O) characterization
and management. It also explored the effect
of water quality on human sensitivity to
earthy/musty odors and public perceptions,
and presented a decision-making tool
to help utilities develop reasonable and
defensible treatment goals for managing
T&O events.
For more information please go to:
http://www.watereuse.org/foundation/
webcasts.
This webcast can be accessed at: http://
www.waterrf.org/resources/webcasts/Pages/
on-demand.aspx.
Research group
Jess Brown, R&D Practice Director
Phone(714) 593-5100
[email protected]
In this Issue
EDITOR
2
Bridging the Gap
Design and PRODUCTION
2
Commentary
Woodland’s Conversion from Oxidation Ditches
to Biological Nutrient Removal
4
Feature Story
Chino II Desalter Concentrate Management Via
Innovative Byproduct Resale & Treatment
6
Project Updates
6
What’s New
8
CRG Spotlight
Erin Mackey
Laura Corrington
Kim Lightner
Matthew Parrott
This publication is printed with soy inks
on FSC®-certified 60% post-consumer
waste recycled content.
re s e ar ch s o lu t io ns
re s e ar ch s o lu t io ns
Carollo Offers WRRF and WaterRF Webcasts
3
COMMENTARY
• Cost-effective conversion to biological
nutrient removal.
• An innovative approach for leveraging
RO concentrate residuals.
• A new, comprehensive study of the
nation’s first direct potable reuse system.
• How a pipe loop, pilot study, and
blending analysis helped address one
utility’s water quality and conveyance
challenges.
re s e ar ch s o lu t io ns
Research Solutions reflects our belief that
creativity, science, and technology must be
integrated with sound engineering to meet
the complex challenges facing our industry.
Challenges like aging infrastructure,
increasingly stringent water quality and
discharge requirements, the movement
toward sustainability, and growing water
supply shortages require innovative
thinking: thinking that bridges the gap from
research and development to real world
solutions.
2
We hope that Research Solutions provides
you with new ideas and case studies that
help you address your water needs. Please
do not hesitate to contact the primary
authors or me directly for more information
on any of these articles.
600
Average Horsepower Usage
Welcome to the Fall
2013 issue of Research
Solutions, a quarterly
publication of the
Carollo’s R&D Practice, also known as the
Carollo Research Group (CRG). CRG, a
diverse team of engineers, scientists, and
researchers located throughout the country,
is focused on bridging the gap between
fundamental research and practical,
innovative, and reliable solutions for those
we serve. Research Solutions features articles
that demonstrate Carollo’s capabilities to
develop and implement advanced processes,
technologies, and tools in the water
industry. You’ll also find commentary about
industry developments and announcements
about recent publications, webcasts, awards,
and new staff. The Fall 2013 issue discusses:
700
MLR Pumping
RAS Pumping
Anoxic Zone Mixing
Aeration
500
400
Constructability and
Implementation
300
200
Figure 2. CFD modeling shows that aeration creates a strong recirculation pattern and
supplemental aeration or mixing is not needed on the sideslopes.
100
0
Existing Ox Ditch
MLE with Diffused Aeration
Figure 1. The City will reduce power usage by almost 200 hp with this project.
Woodland’s Conversion from Oxidation
Ditches to Biological Nutrient Removal
By Andre Gharagozian,
P.E. (agharagozian@
carollo.com), Katy
Rogers, P.E., Rob Hunt,
P.E., and Ed Wicklein,
P.E.; and Mark Cocke
[City of Woodland, CA]
The City of Woodland, CA, serves a
population of 56,000 and owns, operates,
and maintains a wastewater collection
system and Water Pollution Control Facility
(WPCF). The WPCF is permitted for
tertiary treatment of 10.4 million gallons
per day (mgd) using oxidation ditches with
brush rotor aeration and cloth media filters.
However, at current dry weather flows of
5.5 mgd, the aeration equipment cannot
deliver sufficient oxygen when 3 of the 4
ditches are in service. Additionally, the City
is planning for an effluent nitrate limit of
10 mg/L in their next NPDES discharge
permit, requiring conversion to biological
nutrient removal (BNR). Carollo is
currently designing modifications to convert
to BNR and address the aeration deficiency.
The project is at 90-percent design and will
advertise for bids at the end of the year.
BNR Process and High-Efficiency
Turbo Blowers Selection
Several aeration and BNR alternatives
were considered during predesign. The
BNR alternatives included constructing
new tanks to serve as anoxic zones in a
Modified Ludzack-Ettinger (MLE) process
configuration, retrofitting the existing
ditches to MLE without constructing
new tanks, and operating the ditches in a
simultaneous nitrification-denitrification
mode. The aeration alternatives included
adding more brush rotors, installing fine
bubble diffusers to supplement the rotors,
and replacing the rotors with a diffused
aeration system. The best approach for the
City was to retrofit the existing ditches
to MLE and replace the rotors with fine
bubble diffusers supplied by high-efficiency
turbo blowers. This approach was selected
because: 1) retrofit to MLE does not require
constructing costly new tanks; and
2) converting to diffused aeration provides
operational flexibility for successful nutrient
removal and significant energy savings.
Figure 1 illustrates the anticipated energy
savings, which translates to approximately
$160,000 per year in reduced costs at
startup.
Aeration and Mixing Challenges in
Basins with Sideslopes
Converting to MLE means the ditch will be
partitioned into discrete aerobic and anoxic
zones with weir walls and the mixed liquor
return will be pumped from the last aerobic
zone to the anoxic zone. The design of the
mixing and aeration system was unique due
to the unorthodox ditch geometry—the
walls are not vertical and instead have a
1:1 sideslope. The area directly above the
sideslopes contains 40 percent of the ditch
volume, which raised several questions:
1) Are diffusers needed on the sideslopes to
maintain sufficient dissolved oxygen?
2) Will the sideslopes affect the
performance and efficiency of the diffusers?
and 3) Are mixers needed on the sideslopes
to prevent solids deposition? Of particular
concern were the ends of the ditch, where
the 180-degree bend means an even higher
percentage of the volume is above the
sideslope.
To answer these questions, 3D
computational fluid dynamic (CFD)
modeling was used. The CFD model
included user-defined functions for solids
transport and aeration. This was necessary
for the model to properly account for the
density effects of having solids and air in the
wastewater, which significantly influences
the fluid flow pattern. Figure 2 depicts
the velocity and air outputs for one of
the simulations, showing that the upward
velocity from the diffused aeration system
creates a strong mixing and recirculation
pattern over the side slope. Therefore,
diffusers or mixers above the sideslopes
are not needed. See the Winter 2013 issue
of Research Solutions for a more detailed
description of the CFD modeling and
different types of mixers evaluated.
While the strong recirculation pattern is
good for mixing, there are concerns that it
accelerates the upward velocity of the air
bubbles, reducing contact time and oxygen
transfer efficiency. Field test data provided
by a major diffuser manufacturer were used
to assess this concern. Results showed that
diffuser efficiency was inversely proportional
to the depth and diffuser flux rate. Deeper
basins and higher diffuser flux rates create
stronger recirculation patterns. Figure 3
illustrates this relationship, which was
accounted for in the design. Since there
is some uncertainty in the performance,
diffuser specifications will require that
blanks be provided to facilitate adding
diffusers in the future, if needed.
Water Conservation and a
Changing Supply Means
Flexibility Is Needed
Like all wastewater treatment plants, the
modifications will be constructed while
the WPCF is in operation. In addition to
the regulatory and capacity drivers, project
constructability is also a factor. The City
currently operates with 3 of the 4 ditches
in service; therefore, improvements can
be made one ditch at a time with minimal
operational impact. However, the aeration
system is at capacity, so any delays in
implementation or increase in flow or load
would require supplemental aeration during
construction, adding complexity and cost.
The project cost related to BNR upgrade
and improved aeration capacity is
approximately $12 million, amounting to
roughly $1 per gallon. The City’s ability to
implement this BNR conversion at such
a low cost is primarily through reusing
existing infrastructure. While basins with
sideslopes pose challenges for mixing
and aeration, they are definitely worth
salvaging!
Like many communities, the City is
implementing measures to promote water
conservation. Water conservation will
increase the concentration of nutrients in
the WPCF influent over time. Therefore,
the process will need
25%
to operate at higher
18' Side Water Depth
efficiencies in the future
14' Side Water Depth
to meet the fixed effluent
20%
nitrate limit of 10 mg/L.
For example, with an
influent total nitrogen
15%
(TN) concentration of
40 mg/L today, the BNR
process needs to perform
10%
at 75-percent efficiency
to meet its effluent
limit. In the future,
5%
TN concentrations
may approach 60 mg/L
and the process would
0%
1
2
3
0
need to perform at
85-percent efficiency
Air Flow per Diffuser (scfm)
and potentially require
Figure 3. The tank depth and air flow rate appears to affect the
enhancements, such as
diffuser transfer efficiency.
adding supplemental
carbon. Space was left on Source: Adapted from Redmond Engineering Company, Denton Creek, Texas
the site if this change is
- Report of the Clean Water Test Results – Sanitaire/ABJ Project 02-5130a –
required.
SBR Basin #1, July 16, 2004.
re s e ar ch s o lu t io ns
Jess Brown, Ph.D., P.E.
R&D Practice Director
The City’s water supply will be changing
from groundwater to surface water sources
in the next 5 years. This will significantly
reduce the wastewater alkalinity, which is
needed to support the biological reactions
in a BNR process. To mitigate this, the
project includes storage and feed facilities
for magnesium hydroxide.
Reduction in Transfer Efficiency
Bridging the Gap
3
FEATURESTORY
Chino II Desalter Concentrate Management
Via Innovative Byproduct Resale & Treatment
Introduction
re s e ar ch s o lu t io ns
With more than 800 wells, the Chino
Groundwater Basin in Southern California
provides a critical water supply for
agriculture, industry, and public drinking
water suppliers. Although over pumping
of groundwater has resulted in subsidence
in some areas of the Chino Basin, there
is also a hydraulic surcharge that results
in overflow of contaminated groundwater
to the Santa Ana River. The primary
groundwater contaminants of concern are
total dissolved solids (TDS), nitrates, and
volatile organic compounds (VOCs).
4
current mineral content of the groundwater
treated at the Chino II RO facilities, the
primary RO recovery is 83.5 percent. The
remaining 16.5 percent is discharged into
the Inland Empire Brine Line (IEBL) line as
RO concentrate.
The heart of the design of the Chino II
Concentrate Reduction Facility (CRF) is a
high-rate pellet softening and solids contact
clarifier system to remove the limiting
foulants (specifically calcium and silica)
from the primary RO concentrate. Seeded
calcite precipitation occurs in the fluidized
pellet reactors, where hard and durable
pellets are generated, as shown in the
photo above. The pellets naturally dewater
and can be easily transported compared
to the thick, heavy, wet sludge produced
by a conventional softening process. The
produced pellets are a value-added product
that can be used in a variety of industrial
Due to the turbid nature of the pellet
reactor effluent solids, contact clarification
is required to remove magnesium solids
that are formed in the pellet reactors and
carry over due to their lower density. After
the fouling compounds are reduced in the
pellet reactor and the clarifier, the softened
primary RO concentrate is polished with
dual media filters. The filtered effluent is
sent as feed to the secondary RO (SRO)
systems. Treated water will be blended
with the primary RO permeate, and SRO
concentrate will be disposed of into the
IEBL. Using this approach, total water
recovery from the RO system at Chino II
will be increased from 83.5 percent to as
high as 95 percent, substantially reducing
Calcium carbonate pellets generated from
the pellet softener.
the volume of brine disposed into the IEBL,
while increasing permeate production.
Chino II CRF Overall Process
A process flow diagram for the proposed
concentrate reduction facility is shown in
Figure 1. The schematic shows the following
major process elements:
• An energy recovery system upstream
of the pellet reactor to recover
excess energy from the primary RO
concentrate.
Figure 2. Chino II CRF dewatering building.
• Pellet reactor softener system to remove
QQ
•
QQ
•
•
The Chino II Desalter (Chino II) began
operation in 2006 to expand the capacity
of the groundwater treatment system with
a combined ion exchange (IX) and reverse
osmosis (RO) treatment capacity of
10 mgd. The Chino II is managed and
operated by the Chino Basin Desalter
Authority (CDA). The IX and RO
treatment trains in Chino II are used to
treat brackish groundwater from eight
wells that also have elevated nitrate
concentrations. A 6.5-mgd expansion of the
Chino II RO plant has been constructed.
However, due in part to the high cost of
waste brine disposal, the CDA is evaluating
means of maximizing the efficiency of the
RO treatment system at Chino II to reduce
brine disposal costs and increase permeate
production.
•
•
•
•
calcium carbonate and some silica from
the primary concentrate.
Solids contact clarifier to remove the
carryover of calcium, magnesium, and
silica particles.
Granular media filters to polish the
clarifier effluent.
SRO system to treat the softened and
filtered primary RO concentrate to
produce permeate (product water) and
brine (SRO concentrate).
Filter waste washwater basin to
collect media filter spent backwash
water, gravity thickener supernatant,
pellet storage hopper drainage, and
supernatant from the dewatering
process. The waste washwater is pumped
to the clarifier influent for treatment
and recovery.
Backwash basin to store backwash and
surface wash water for the granular
media filters and equalize SRO feed.
Gravity thickener and mechanical
dewatering to treat clarifier sludge.
The following chemicals and materials
are required:
QQ
Basis of Design
RO recovery is typically limited by
precipitation of sparingly soluble salts on
the surface of the membranes. With the
applications, thus converting a waste
stream of the Chino II process into a usable
commodity.
QQ
Figure 1. Chino II CRF process flow diagram.
Lime and caustic soda are used to
raise the pH and cause precipitation
of the dissolved solids within the
pellet reactor and clarifier.
Seed material (silica sand or calcium
carbonate) is fed to the pellet reactor
to act as the nucleus for calcium
carbonate precipitation.
QQ
QQ
QQ
Ferric chloride is applied as a
coagulant in the clarifier to improve
solids settleability.
Polymer is added in the clarifier
as a gravity thickener to improve
solids settleability, and ahead of
the mechanical dewatering process
to improve the performance of the
centrifuge.
Threshold inhibitor is applied to the
SRO feed to control precipitation of
silica and calcium carbonate.
Sulfuric acid is fed to the clarifier
effluent to prevent continued
calcium carbonate precipitation in
the media filters and SRO systems.
Soda ash is added upstream of the
pellet reactors and is used to provide
a source of carbonate alkalinity.
The concentrate reduction process
reduces the overall dissolved solids mass
loading to the IEBL pipeline through the
removal of calcium carbonate, magnesium
hydroxide, and silica from the brine
stream as solid precipitates. Figure 2 shows
the 3-D rendering of the Dewatering
Building at the Chino II CRF, where the
pellet softening, solids clarification, and
mechanical dewatering process are located.
While Chino II continues to remove the
same amount of dissolved solids from the
groundwater basin, a smaller portion is
discharged to the IEBL pipeline as a liquid
waste and a significant amount of solids
leave the Chino II site by truck in the form
of pellets and dewatered sludge.
re s e ar ch s o lu t io ns
By Brandon Yallaly, P.E.
([email protected]),
Winnie Shih, Ph.D.,
and John Meyerhofer;
Jack Safely [formerly
with Western Municipal
Water District], Curtis Paxton [Chino
Basin Desalter Authority], and Issam
Najm, Ph.D., P.E. [WQTS]
5
PROJECTUPDATES
WHAT’SNEW
Faced with an extended drought in the
State of Texas, the City of San Angelo
began to explore its best available water
supply option: the Hickory Aquifer well
field. However, there were some challenges
to overcome: the well field is approximately
60 miles away from the City’s treatment
plant and the water contains significant
amounts of radium and iron.
The challenges presented by the water
quality had potential impacts on the design
of treatment and raw water conveyance
systems and distribution of the finished
water. In each of these cases, data were
either limited or site-specific information
was needed. Bench and pilot studies were
invaluable tools to develop good design and
operational criteria for treatment, raw water
conveyance, and blending the finished
groundwater with the existing finished
surface water.
Raw Water Conveyance. A pipe loop study
was conducted on the raw groundwater to
evaluate whether radium may co-precipitate
with other inorganic constituents in the raw
worked well, but the City opted
water pipeline
KEY Team Members
to select the single use IX
to a point at
Justin Sutherland, Ph.D., P.E.
technology to remove radium
which the waste
([email protected])
because it offered the operational
from a pipe
Greg Pope, Ph.D., P.E.
flexibility and waste disposal
pigging operation
Hutch Musallam, P.E.
alternatives that the City desired.
would require
disposal in a low-level radioactive waste
Finished Water Blending. Since the
site. An interesting finding of this study
low TDS groundwater from the Hickory
was that the use of a phosphate inhibitor
Aquifer will be blended with the City’s
appeared to slightly increase pipe scale
high TDS surface waters, it was necessary
weight and significantly increase the
to investigate the effect of blending both
radium concentration in the pipe scale and,
waters on the distribution system. Results of
therefore, should be avoided for pipeline
the blending study showed that the surface
operation. Otherwise, the results of the
water and groundwaters blend well and that
study demonstrated that there was no valid
the chloramines stability improved with
concern about significant levels of radium
increased groundwater in the blend.
depositing on the pipe wall.
Treatment. Carollo worked with the City
to design, construct, and operate pilot
testing facilities to evaluate three IX resins
for radium removal from the groundwater.
Two of the resins were viable options. The
City wished to evaluate other treatment
technologies, and Carollo led a second
pilot plant investigation that tested three
RO membrane systems. Both technologies
The results of the studies conducted by
Carollo—viable options for radium and iron
removal, waste disposal, water blending, and
the impact of radium on the conveyance
system, among others—were invaluable
guides to the final design and construction
phases of the project. This work is
scheduled for final completion in 2014.
WHAT’SNEW
re s e ar ch s o lu t io ns
WRRF Publishes Low Energy Treatment Schemes Report
6
Carollo is pleased to announce the
category based on
KEY Team Member
publication of WateReuse Report
market readiness,
Andrew Salveson, P.E.
10-06A, Challenge Projects on
having the highest
([email protected])
Low Energy Treatment Schemes for
potential to save energy
Water Reuse, Phase 1, authored by Andrew
and costs, and being ready for use at fullSalveson, Erin Mackey, Graham Juby,
scale. The recommended technologies for
Rudy Kilian, and Rod Reardon (Carollo);
Phase II research were: the anaerobic MBR
Julian Sandino (CH2MHill); Jean Debroux
(AnMBR) and the main-stream anammox
(Kennedy/Jenks Consultants); Perry
process. Other processes also recommended
McCarty (Consultant); Laura Shenkar (The
for testing, should outside funding become
Artemis Project); and Paul O’Callaghan (O2
available, were pasteurization, gasification,
Environmental).
WaterTectonics electrocoagulation, and the
Emefcy’s SABRE process. Each process is
This study evaluated conventional
briefly described in the report.
treatment systems, emerging treatment
systems, and innovative treatment concepts
This report was jointly sponsored by the
for low-energy wastewater treatment
WRRF, the Water Environment Research
and wastewater reclamation. The study
Foundation, and the U.S. Department of
identified two key treatment technologies
Interior Bureau of Reclamation.
from the Emerging Treatment Systems
This report is available through the WRRF
website (www.watereuse.org).
Carollo Awards 2013 Scholarship to ASU Student
Carollo awards a $10,000 scholarship
annually to a master’s student engaging
in water-energy nexus issues for water,
wastewater, or reuse. Alexandra (Allie)
Bowen, E.I.T., was awarded the 2013
Carollo Engineers Scholarship at the
AWWA Annual Conference & Exhibition
in Denver, CO.
Allie is a graduate research assistant at
Arizona State University’s School of
Sustainable Engineering and the Built
Environment. At ASU, she’s been involved
with research focused on the occurrence
and speciation of metals throughout
potable water treatment plants and power
generating systems. She’s also developing an
in-situ passive sampler for water treatment
plants and is co-founder of the ASU
student group Graduate Students for the
Environment.
Prior to ASU, Allie was an undergraduate
research assistant at the University of New
Hampshire, where she investigated the
use of UV for RO pretreatment and also
studied oxidative degradation mechanisms
of pharmaceuticals and personal care
products.
Congratulations, Allie!
Texas Water Development Board Study to Examine
Nation’s First Direct Potable Reuse System
Jess Brown (left) and former AWWA
President Charlie Anderson (right)
awarded the 2013 Carollo Engineers
Scholarship to Allie Bowen, a graduate
research assistant at Arizona State
University.
direct measurement of pathogens (virus,
protozoa, and bacteria) and trace chemicals
(pharmaceuticals and personal care
products, hormones, flame retardants, and
others) as well as a number of indicator
and surrogate measurements that can be
used to monitor treatment performance. To
support development of a robust monitoring
approach that is practicable for utilities
of various sizes and financial means, our
testing protocol will include measurement
of less costly surrogates wherever possible
to complement the testing for primary
parameters, and will define correlations
between primary parameters and surrogates.
Across the country, successful
A team led by
KEY Team Members
indirect potable reuse (IPR)
Carollo was recently
Eva Steinle-Darling, Ph.D., P.E.
projects are now creating
selected by the Texas
([email protected])
more than 100 mgd of
Water Development
Andrew Salveson, P.E.
potable water; several have
Board to perform a
been doing it safely for nearly half a century,
comprehensive evaluation and monitoring
with no ill effects on public health. These
study of the RWPF in Big Spring. An
include the Orange County Water District,
overarching goal of the study is to
CA; West Basin Municipal Water District,
determine the efficacy and reliability of
CA; El Paso Water Utilities, TX; Upper
DPR treatment for implementation across
Occoquan Services Authority, VA; and the
the State of Texas, and ultimately support
City of Scottsdale, AZ. In May of this year,
the development of DPR projects across the
the first of several Texas projects exploring
nation.
the path towards direct potable reuse
Big Spring Wastewater Treatment Plant
(DPR), implemented by the Colorado River
Our study will include:
Municipal Water District (CRMWD) in Big
Spring, TX, began augmenting raw water
• A comprehensive and independent
supplies directly with advanced treated
evaluation of RWPF process
Raw Water Production Facility
reclaimed water.
performance.
• Development and implementation of
The advanced treatment processes
a detailed testing protocol.
implemented at the Raw Water Production
• A guidance document that
Facility (RWPF) in Big Spring include
recommends monitoring approaches
CRMWD Raw Water Pipeline
microfiltration, RO, and UV-peroxide based
for DPR.
advanced oxidation, a configuration that
is similar to several of the IPR projects
For this study, Carollo will build upon
listed above. What makes Big Spring
its nation-leading research efforts
Water Treatment Plants
unique among potable reuse projects is
on treatment and monitoring for
the lack of an environmental buffer, which
potable reuse applications, developed
in conventional IPR projects provides
in partnership with both research
IPR and DPR involve the use of additional
additional treatment and response time in
agencies and utility clients. Our
advanced treatment processes to further purify the
case of a water quality failure.
team will develop and implement
water for reuse as a potable water source.
a testing protocol that includes
re s e ar ch s o lu t io ns
San Angelo’s Hickory Water Supply Project Develops Criteria for Treatment,
Raw Water Conveyance, and Blending of Groundwater and Surface Water
7
PROJECTUPDATES
WHAT’SNEW
Faced with an extended drought in the
State of Texas, the City of San Angelo
began to explore its best available water
supply option: the Hickory Aquifer well
field. However, there were some challenges
to overcome: the well field is approximately
60 miles away from the City’s treatment
plant and the water contains significant
amounts of radium and iron.
The challenges presented by the water
quality had potential impacts on the design
of treatment and raw water conveyance
systems and distribution of the finished
water. In each of these cases, data were
either limited or site-specific information
was needed. Bench and pilot studies were
invaluable tools to develop good design and
operational criteria for treatment, raw water
conveyance, and blending the finished
groundwater with the existing finished
surface water.
Raw Water Conveyance. A pipe loop study
was conducted on the raw groundwater to
evaluate whether radium may co-precipitate
with other inorganic constituents in the raw
worked well, but the City opted
water pipeline
KEY Team Members
to select the single use IX
to a point at
Justin Sutherland, Ph.D., P.E.
technology to remove radium
which the waste
([email protected])
because it offered the operational
from a pipe
Greg Pope, Ph.D., P.E.
flexibility and waste disposal
pigging operation
Hutch Musallam, P.E.
alternatives that the City desired.
would require
disposal in a low-level radioactive waste
Finished Water Blending. Since the
site. An interesting finding of this study
low TDS groundwater from the Hickory
was that the use of a phosphate inhibitor
Aquifer will be blended with the City’s
appeared to slightly increase pipe scale
high TDS surface waters, it was necessary
weight and significantly increase the
to investigate the effect of blending both
radium concentration in the pipe scale and,
waters on the distribution system. Results of
therefore, should be avoided for pipeline
the blending study showed that the surface
operation. Otherwise, the results of the
water and groundwaters blend well and that
study demonstrated that there was no valid
the chloramines stability improved with
concern about significant levels of radium
increased groundwater in the blend.
depositing on the pipe wall.
Treatment. Carollo worked with the City
to design, construct, and operate pilot
testing facilities to evaluate three IX resins
for radium removal from the groundwater.
Two of the resins were viable options. The
City wished to evaluate other treatment
technologies, and Carollo led a second
pilot plant investigation that tested three
RO membrane systems. Both technologies
The results of the studies conducted by
Carollo—viable options for radium and iron
removal, waste disposal, water blending, and
the impact of radium on the conveyance
system, among others—were invaluable
guides to the final design and construction
phases of the project. This work is
scheduled for final completion in 2014.
WHAT’SNEW
re s e ar ch s o lu t io ns
WRRF Publishes Low Energy Treatment Schemes Report
6
Carollo is pleased to announce the
category based on
KEY Team Member
publication of WateReuse Report
market readiness,
Andrew Salveson, P.E.
10-06A, Challenge Projects on
having the highest
([email protected])
Low Energy Treatment Schemes for
potential to save energy
Water Reuse, Phase 1, authored by Andrew
and costs, and being ready for use at fullSalveson, Erin Mackey, Graham Juby,
scale. The recommended technologies for
Rudy Kilian, and Rod Reardon (Carollo);
Phase II research were: the anaerobic MBR
Julian Sandino (CH2MHill); Jean Debroux
(AnMBR) and the main-stream anammox
(Kennedy/Jenks Consultants); Perry
process. Other processes also recommended
McCarty (Consultant); Laura Shenkar (The
for testing, should outside funding become
Artemis Project); and Paul O’Callaghan (O2
available, were pasteurization, gasification,
Environmental).
WaterTectonics electrocoagulation, and the
Emefcy’s SABRE process. Each process is
This study evaluated conventional
briefly described in the report.
treatment systems, emerging treatment
systems, and innovative treatment concepts
This report was jointly sponsored by the
for low-energy wastewater treatment
WRRF, the Water Environment Research
and wastewater reclamation. The study
Foundation, and the U.S. Department of
identified two key treatment technologies
Interior Bureau of Reclamation.
from the Emerging Treatment Systems
This report is available through the WRRF
website (www.watereuse.org).
Carollo Awards 2013 Scholarship to ASU Student
Carollo awards a $10,000 scholarship
annually to a master’s student engaging
in water-energy nexus issues for water,
wastewater, or reuse. Alexandra (Allie)
Bowen, E.I.T., was awarded the 2013
Carollo Engineers Scholarship at the
AWWA Annual Conference & Exhibition
in Denver, CO.
Allie is a graduate research assistant at
Arizona State University’s School of
Sustainable Engineering and the Built
Environment. At ASU, she’s been involved
with research focused on the occurrence
and speciation of metals throughout
potable water treatment plants and power
generating systems. She’s also developing an
in-situ passive sampler for water treatment
plants and is co-founder of the ASU
student group Graduate Students for the
Environment.
Prior to ASU, Allie was an undergraduate
research assistant at the University of New
Hampshire, where she investigated the
use of UV for RO pretreatment and also
studied oxidative degradation mechanisms
of pharmaceuticals and personal care
products.
Congratulations, Allie!
Texas Water Development Board Study to Examine
Nation’s First Direct Potable Reuse System
Jess Brown (left) and former AWWA
President Charlie Anderson (right)
awarded the 2013 Carollo Engineers
Scholarship to Allie Bowen, a graduate
research assistant at Arizona State
University.
direct measurement of pathogens (virus,
protozoa, and bacteria) and trace chemicals
(pharmaceuticals and personal care
products, hormones, flame retardants, and
others) as well as a number of indicator
and surrogate measurements that can be
used to monitor treatment performance. To
support development of a robust monitoring
approach that is practicable for utilities
of various sizes and financial means, our
testing protocol will include measurement
of less costly surrogates wherever possible
to complement the testing for primary
parameters, and will define correlations
between primary parameters and surrogates.
Across the country, successful
A team led by
KEY Team Members
indirect potable reuse (IPR)
Carollo was recently
Eva Steinle-Darling, Ph.D., P.E.
projects are now creating
selected by the Texas
([email protected])
more than 100 mgd of
Water Development
Andrew Salveson, P.E.
potable water; several have
Board to perform a
been doing it safely for nearly half a century,
comprehensive evaluation and monitoring
with no ill effects on public health. These
study of the RWPF in Big Spring. An
include the Orange County Water District,
overarching goal of the study is to
CA; West Basin Municipal Water District,
determine the efficacy and reliability of
CA; El Paso Water Utilities, TX; Upper
DPR treatment for implementation across
Occoquan Services Authority, VA; and the
the State of Texas, and ultimately support
City of Scottsdale, AZ. In May of this year,
the development of DPR projects across the
the first of several Texas projects exploring
nation.
the path towards direct potable reuse
Big Spring Wastewater Treatment Plant
(DPR), implemented by the Colorado River
Our study will include:
Municipal Water District (CRMWD) in Big
Spring, TX, began augmenting raw water
• A comprehensive and independent
supplies directly with advanced treated
evaluation of RWPF process
Raw Water Production Facility
reclaimed water.
performance.
• Development and implementation of
The advanced treatment processes
a detailed testing protocol.
implemented at the Raw Water Production
• A guidance document that
Facility (RWPF) in Big Spring include
recommends monitoring approaches
CRMWD Raw Water Pipeline
microfiltration, RO, and UV-peroxide based
for DPR.
advanced oxidation, a configuration that
is similar to several of the IPR projects
For this study, Carollo will build upon
listed above. What makes Big Spring
its nation-leading research efforts
Water Treatment Plants
unique among potable reuse projects is
on treatment and monitoring for
the lack of an environmental buffer, which
potable reuse applications, developed
in conventional IPR projects provides
in partnership with both research
IPR and DPR involve the use of additional
additional treatment and response time in
agencies and utility clients. Our
advanced treatment processes to further purify the
case of a water quality failure.
team will develop and implement
water for reuse as a potable water source.
a testing protocol that includes
re s e ar ch s o lu t io ns
San Angelo’s Hickory Water Supply Project Develops Criteria for Treatment,
Raw Water Conveyance, and Blending of Groundwater and Surface Water
7
Traci Brooks
Traci Brooks received
her B.A. in Physics from
Austin College and her
M.S. in Civil Engineering
from the University of
Colorado at Boulder. Her
graduate research looked at the degradation
of chlorine by UV radiation in the presence
of nitrates.
She joined Carollo’s Boise office as a
full-time employee in January 2012, after
completing a 2-month summer internship.
During her internship, she participated in
the validation of a Xylem-WEDECO K143
UV reactor. This testing was conducted
at flows up to 72 mgd, and was the largest
validation of its kind performed to date.
At Carollo, Traci has taken increasing
responsibility as the lead validation engineer
responsible for testing more than ten UV
reactors at Carollo’s Portland UV Validation
Facility. She also works on data analysis,
report writing, and reviewing for the
validation projects. Traci is looking forward
to being involved in other UV technology
projects with Carollo.
Varun Gandhi,
Ph.D.
Dr. Varun Gandhi
received his B.S.,
M.S., and Ph.D.
in Environmental
Engineering from the Georgia Institute
of Technology. His Ph.D. research was on
the hydrodynamics and dose delivery in a
lab-scale UV reactor using laser-induced
fluorescence. Using this technology, he has
also analyzed the dose delivery in an ozone
contactor and the flow characteristics of
dense brine disposal through multi-port and
rosette-shaped diffusers. He has authored
or co-authored 10 peer-reviewed and
conference papers related to various aspects
of water treatment.
While at Carollo, Varun has worked on
validation testing of multiple UV reactors
at Carollo’s Portland UV Validation Facility,
along with data analysis and report writing.
He has also developed CFD models of UV
reactors to compare treatment efficiency
and develop action spectra correction
factors for utilities around the U.S. In
addition, he has developed CFD models for
an ozone disinfection reactor.
Phoenix, Arizona
Yuma, Arizona
Fresno, California
Inland Empire, California
Los Angeles, California
Orange County, California
Pasadena, California
Sacramento, California
San Diego, California
San Francisco, California
Sunnyvale, California
Ventura County, California
Walnut Creek, California
Denver (Broomfield), Colorado
Denver (Littleton), Colorado
Broward County, Florida
Miami, Florida
Orlando, Florida
Palm Beach County, Florida
Sarasota, Florida
Boise, Idaho
Chicago, Illinois
Kansas City, Missouri
Omaha, Nebraska
Las Vegas, Nevada
Reno, Nevada
Oklahoma City, Oklahoma
Portland, Oregon
Austin, Texas
Dallas, Texas
Fort Worth, Texas
Houston, Texas
Salt Lake City, Utah
Seattle, Washington
Research SOLUTIONS
WHAT’SNEW
8
Carollo will offer a webcast through the
WateReuse Research Foundation (WRRF)
for WateReuse Project 11-10, Evaluation of
Risk Reduction Principles for Direct Potable
Reuse.
Carollo also offered a webcast on September
19th through the Water Research
Foundation (WaterRF) for WaterRF Project
3032, A Decision Tool for Earthy/Musty Taste
and Odor Control.
Date: November 14, 2-3 pm EST.
Value: The webcast will highlight Carollo’s
leading edge work in implementing direct
reuse. It will also explore the costs and
benefits to different risk management
alternatives for direct potable reuse and
its implications for the future of reclaimed
water use.
This webcast highlighted Carollo’s expertise
in taste and odor (T&O) characterization
and management. It also explored the effect
of water quality on human sensitivity to
earthy/musty odors and public perceptions,
and presented a decision-making tool
to help utilities develop reasonable and
defensible treatment goals for managing
T&O events.
For more information please go to:
http://www.watereuse.org/foundation/
webcasts.
This webcast can be accessed at: http://
www.waterrf.org/resources/webcasts/Pages/
on-demand.aspx.
Research group
Jess Brown, R&D Practice Director
Phone(714) 593-5100
[email protected]
In this Issue
EDITOR
2
Bridging the Gap
Design and PRODUCTION
2
Commentary
Woodland’s Conversion from Oxidation Ditches
to Biological Nutrient Removal
4
Feature Story
Chino II Desalter Concentrate Management Via
Innovative Byproduct Resale & Treatment
6
Project Updates
6
What’s New
8
CRG Spotlight
Erin Mackey
Laura Corrington
Kim Lightner
Matthew Parrott
This publication is printed with soy inks
on FSC®-certified 60% post-consumer
waste recycled content.
re s e ar ch s o lu t io ns
re s e ar ch s o lu t io ns
Carollo Offers WRRF and WaterRF Webcasts
3