In this Issue. 3researchsolutions. Bridging the Gap. Commentary Why Should Wastewater Agencies Consider an Integrated Master Planning Approach?

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1 In this Issue Bridging the Gap Commentary Why Should Wastewater Agencies Consider an Integrated Master Planning Approach? Feature Story Engineered Biofiltration : Taking Improved Biofilter Performance to Full-Scale Project Updates What s New 3researchsolutions

2 researchsolutions Bridging the Gap Jess Brown, Ph.D., P.E. R&D Practice Director Welcome to the Spring/ Summer 013 issue of Research Solutions. This issue highlights how Carollo is working to bridge the gap between good ideas and practical solutions in master planning, water/energy life-cycle inventories, Engineered Biofiltration, and automated meter reading. You ll also read about a recent publication on minimizing brominated DBPs, learn about a new PVCbased ultrafiltration membrane, and we ll introduce you to one of Carollo s R&D Practice engineers. Plan to Prioritize. Performing a comprehensive master plan can help an agency prioritize resource investment and allocation a particularly valuable exercise during lean times. This work requires asset risk analyses, rigorous hydraulic modeling, and non-process facilities planning and results in an optimized long-term CIP. Modeling the Green. Carollo developed a framework for quantitatively assessing the life-cycle water and energy embedded in water infrastructure resulting in an efficient, dynamic lifecycle inventory model, which can be used to improve system performance while minimizing environmental impact. Passive No More. Historically, the bio portion of biofilters hasn t received much attention, as particle/turbidity removal has ruled the day. This article discusses how Carollo is engineering biofiltration at full-scale facilities, giving both filtration and biological activity top billing to improve overall water treatment and hydraulic performance. To Retrofit or Replace That Is the Question. Read about how Carollo s Business Solutions Group performed a life-cycle cost analysis for a planned meter replacement program. This work balanced revenue loss due to inaccurately metered water with the cost of replacing old meters. I hope you find some useful information in these articles. Please let me or the primary authors know if you have any questions or comments. COMMENTARY Why Should Wastewater Agencies Consider an Integrated Master Planning Approach? By Andre Gharagozian, P.E. (agharagozian@ carollo.com), Katy Rogers, P.E., Tim Loper, P.E., Rebecca Overacre, P.E., and EJ Shalaby [West County Wastewater District, CA] The West County Wastewater District (District) serves a population of 93,000. It owns, operates, and maintains a wastewater collection system with 49 miles of sewer, 17 lift stations, 6 miles of force mains, and a Water Pollution Control Plant (WPCP) with a capacity of 1.5-million gallons per day (mgd). Like many agencies in the San Francisco Bay Area, growth is limited, but aging infrastructure, wet weather capacity, and regulations must still be addressed into the future. The District has performed numerous studies on individual system components, including the trunk sewers, the WPCP, and some non-process facilities. However, these studies have been performed independent of each other, which has made prioritizing system needs challenging. Recognizing this limitation, the District hired Carollo to develop an integrated District-wide master plan (Master Plan) for all of the District s facilities, including the collection system, the WPCP, and the non-process functions such as the administration, laboratory, storage, and maintenance facilities. System-Wide Prioritization of CIP Projects The main benefit of preparing an integrated Master Plan is that the needs of the collection system, WPCP, and non-process facilities can be prioritized with each other. This is important. It gives the District some assurance that financial resources are being directed towards the highest needs. It also makes the District s capital improvement program (CIP) more legally defensible. Bay Area agencies are under intense scrutiny from environmental non-governmental organizations (NGOs) that bring lawsuits in the event of violations. The approach used to prioritize projects in the Master Plan focused, in part, on minimizing the chance that violations will occur; but should such an event happen, the District will have a strong legal position that they did everything within reason to avoid it. To prioritize renewal projects (i.e., rehabilitation and replacement), Carollo calculated risk scores for each of the District s 1,000 assets, including individual Figure 1. Collection system and WPCP rehabilitation projects were prioritized based on risk scores. Flow Rate (mgd) Required Storage 0 0:00 1:00 0:00 1:00 0:00 1:00 0:00 1:00 0:00 1:00 0:00 Storm Duration (Time of Day) pieces of equipment, pipes, and manholes (Figure 1). Risk is defined as the product of the asset s likelihood of failure (i.e., vulnerability) and the consequence of its failure (i.e., criticality). Carollo used several tools to identify vulnerabilities, including the asset s age, visual inspections of the lift stations and WPCP facilities, and defect ratings determined from the District s closed-circuit television (CCTV) inspections. Criticality was based primarily on an asset s proximity to environmentally sensitive areas and public facilities (i.e., schools or hospitals), and the potential environmental and fiscal impacts of a failure. The higher the risk score, the higher the relative need to renew that asset. The same overall approach, evaluation criteria, and scoring system was used to calculate risk scores for both the collection system and other WPCP assets. As a result, the risk scores for all the assets were comparable, and provided a uniform basis for prioritizing renewal needs. Linkages between Wastewater Collection and Treatment Systems Can Be Explored The rate and quantity of wastewater a collection system conveys has a direct impact on the size and design of the treatment system. This is well understood in the industry. However, the opportunity to explore this relationship is limited if collection system and treatment plant master plans are performed independently. Conducting these master plans in concert allows the engineer to explore the most effective split between collection system and treatment plant improvements. For most treatment plant master plans, peak flow projections are developed based on historical peaking factors. While this is a reasonable method, the approach taken in collection system master plans is far more rigorous and can account for planned changes in land use, infiltration and inflow (I&I) reduction programs, or storm water projects that would affect wastewater flows. In addition, capacity constraints will dampen peak flow in the collection system and improvements to mitigate those constraints may actually increase the peak flows to the plant. Understanding that dynamic is important for planning the WPCP s ability to handle peak wet weather flows. Equalized Flow Figure. Collection system modeling helped establish wet weather storage needs at the WPCP. For the District s Master Plan, an InfoSWMM hydraulic model was developed that included all sewer pipes 6 inches in diameter and larger. The model was calibrated using land use data from the GIS database and months of wet weather flow monitoring. The calibrated model was then used to develop flow projections, identify capacity limitations and necessary improvements in the collection system, and calculate how much hydraulic capacity and wet weather storage volume is needed at the WPCP (Figure ). Having an accurate and precise collection system hydraulic model was highly beneficial. It indicated that the needed size of the wet weather storage basins is driven by the volume of wastewater received at the WPCP, not the peak flow. In addition, the appropriate level of I&I reduction the District should target was identified. Non-Process Facilities Should Be Included in the Plan Space planning for nonprocess facilities is typically ignored in wastewater planning efforts. The District, however, wanted to include these facilities in the Master Plan because their existing non-process facilities are undersized and implementing a 0-year CIP will require increased staff. Furthermore, the District Figure 3. Consolidating all non-process facilities into one campus at the WPCP is expected to improve overall performance and efficiency. desires to improve overall staff efficiency, communication, and collaboration. The District ultimately decided to consolidate all of their facilities into one campus at the WPCP (Figure 3). Including this planning effort in the Master Plan allowed Carollo to coordinate the proposed one-campus concept with space needs for future process facilities. Results Once the entire system was assessed and future needs were identified, improvement alternatives were uniformly evaluated and prioritized in a 0-year CIP. Regulatory improvements are timed based on when regulations are anticipated to take effect, wet weather capacity projects are timed to address the greatest capacity issues first, and renewal projects are timed to address assets in order of failure risk. A governing philosophy to touch each area as few times as possible was applied to ensure renewal projects and other projects in the same area were coordinated. This approach will minimize impacts to service and make design and construction efforts more efficient. The focus of the CIP over the next 5 years will be to replace or rehabilitate the highest risk aging assets (Figure 4). Distribution of 5-Year CIP Cost in Millions by Project Area and Type Engineering Studies ($1.7M) District Facilities Improvements ($9.4M) WPCP Rehabilitation Improvements ($13.4M) WPCP Regulatory and Process Improvements ($18.6M) Total 5-Year CIP Cost: $9.4M CSO Vehicle Replacement ($0.8M) Collection System Rehabilitation Improvements ($40.0M) Collection System Capacity Improvements ($8.5M) Figure 4. The focus of the next 5 years is on rehabilitating and replacing aging assets. 3researchsolutions

3 4researchsolutions FEATURESTORY Engineered Biofiltration : Taking Improved Biofilter Performance to Full-Scale By Chance Lauderdale, Ph.D., P.E. Kara Scheitlin, P.E., and John Zwernemen; Bill Gase, and Michael Buettner [both Arlington Water Utilities, TX] Introduction Engineered Biofiltration involves optimizing filter conditions for increased biological activity and improving water treatment while simultaneously improving hydraulic performance by reducing biological fouling from extracellular polymeric substances (EPS). Recent pilot-scale work performed by Carollo through Water Research Foundation Tailored Collaborations #415 Engineered Biofiltration and #4346 Optimizing Engineered Biofiltration has demonstrated that relatively minor changes in biofilter operation can help utilities achieve these goals. Two strategies that showed significant promise for biofilter optimization included: 1) biological activity enhancement through nutrient supplementation, and/or ) biofoulant minimization through low-level hydrogen peroxide supplementation. The validation of these concepts has now been achieved during full-scale demonstration at the Pierce Burch Water Treatment Plant (PBWTP) in Arlington, TX. Project Purpose For over a decade, the PBWTP has operated a biofiltration process. The PBWTP has 0 biofilters, each capable of treating approximately 3.5 mgd. The filter design includes an underdrain block and gravel media support overlain by 8 inches of sand and 36 inches of granular Lake Arlington Coagulation/ Sedimentation (Alum) Ozonation activated carbon (GAC). Biofiltration at the PBWTP is primarily employed for the removal of particles, regrowth/instability potential, manganese (Mn), and taste and odor (T&O)-causing compounds. Despite generally effective hydraulic and water treatment performance, occasional process upsets indicated that the PBWTP biofiltration process could be further optimized. The purpose of the Engineered Biofiltration Demonstration was to assess whether the nutrient or peroxide biofiltration enhancement strategies could improve the PBWTP process by: Increasing the removal of organic carbon to improve disinfectant (chloramines) stability and to limit distribution system regrowth potential. Improving the removal of Mn to achieve sustained filter effluent concentrations below the secondary maximum contaminant level (MCL) (0.05 mg/l). Improving filter hydraulics for increased filter run times and water treatment efficiency. Study Description Two Pierce Burch biofilters were enhanced with nutrients and hydrogen peroxide during approximately 16 months of testing. A modified demonstration enhancement process schematic is shown in Figure 1. The remaining biofilters were left unenhanced; Three of these were monitored as controls throughout the study. H O H 3 PO 4 GAC Biofilter # GAC Biofilter #6 Control GAC Filters Cl /NH 3 Clearwell Enhancement chemicals were dosed at low concentrations (0.15 mg/l phosphoric acid, 0. mg/l hydrogen peroxide). Performance Improvements Water quality monitoring was conducted on approximately a bi-weekly basis during the demonstration. Water quality was monitored in both the filter influents and effluents. Neither enhancement strategy degraded turbidity removal performance or the treatment of any contaminant. Furthermore, water treatment performance improvements were observed in the nutrient-enhanced biofilter, including organic carbon and Mn removal. Organic Carbon Filter influent dissolved organic carbon (DOC) concentrations averaged approximately.9 mg/l during the test period. Phosphorus supplementation substantially improved organic carbon removal (Figure ). The nutrient-enhanced biofilter was capable of removing 0.7 mg/l, while the control biofilters averaged only 0.4 mg/l. Decreased organic carbon breakthrough in the nutrient-enhanced filter effluent also correlated with decreased chlorine demand and improved chloramines stability. Dissolved Organic Carbon Removal (%) 5% 0% 15% 10% 5% 0% Nutrient Enhancement: Phosphoric Acid (0.15 mg/l) Loading Rate: 5 gpm/ft Average of Control Biofilters (Filter Nos. 16, 18, 0) Manganese Filter influent Mn concentrations averaged approximately 0.06 mg/l during the test period. Both the control and nutrientenhanced biofilters typically removed Mn to concentrations at or below 0.05 mg/l, less than one-half the USEPA Secondary MCL. However, the two control filters did show occasional Mn breakthrough over the MCL, while Mn breakthrough in the nutrientenhanced biofilter effluent remained below detection (0.05 mg/l) throughout the study. Hydraulic Performance Improvements Biofilter runtimes at the PBWTP are currently held constant at 4 hours to prevent irreversible biological fouling. Hydraulic performance was characterized by evaluating filter terminal headloss. Filter headloss data for the control and enhanced biofilters was tracked throughout the study. Both peroxide and nutrient enhancement consistently improved biofilter hydraulics over the controls during several months of sustained operation. Figures 3 and 4 provide representative filter runs for both enhanced and control biofilters. The decreased observed terminal headloss may be used to justify extending the current filter runtime triggers beyond 4 hours if either enhancement strategy is implemented. Interestingly, direct measurement of EPS was performed on select samples of media, verifying that the enhancement strategies generated up to 60 percent less material than the biofilter controls. Nutrient-Enhanced Biofilter (Filter No. ) Conclusions Carollo has recently completed a demonstration at the PBWTP to further evaluate the effectiveness and practicality of nutrient and peroxide enhancement at the full-scale level. Both enhanced biofilters showed improved hydraulic performance and decreased biofouling of filter media. In addition, the nutrient enhancement strategy improved biofilter organics removal for improved effluent stability and decreased the potential for Mn breakthrough. The information collected during this study is expected to enhance the existing knowledge base on biological drinking water treatment. Filter Headloss (ft) Phosphoric Acid Dose: 0.15 mg/l Loading Rate: 5 gpm/ft ~0% decrease in terminal headloss Control Chemical storage and feed pumps. Phosphorous-Enhanced Filter Run Time (hr) Figure 3. Representative filter runs for control and nutrient-enhanced biofilters. Filter Headloss (ft) Hydrogen Peroxide Dose: 0. mg/l Loading Rate: 5 gpm/ft ~15% decrease in terminal headloss Control Peroxide-Enhanced ~15% increase in filter run time ~0% increase in filter run time researchsolutions Figure 1. Existing treatment process configuration with biofilter enhancements added. Figure. Dissolved Organic Carbon (DOC) removal by nutrient enhanced and control biofilters. Filter Run Time (hr) Figure 4. Representative filter runs for control and peroxide-enhanced biofilters.

4 6researchsolutions PROJECTUPDATES MCSD Uses Life-Cycle Cost Benefit Analysis to Improve Water Metering Looking to improve efficiency and accuracy, the McKinleyville Community Services District (MCSD or District) decided to implement an automatic meter reading (AMR) program. Once fully implemented, AMR frees up staff time and prevents the need to hire additional meter readers. Given the cost differential, the District was left with the decision to either replace the existing meters or to simply retrofit them with the new technology. To replace the meter in its entirety would cost $0, including an estimated 0.5 hour of labor. Alternatively, adding a radio head would cost $135, including an estimated 0.5 hour of labor. The District understood that on one hand retrofitting old and inaccurate meters may lead to further considerable revenue losses as a result of unmetered water. On the other hand, fully replacing the meters could incur unnecessary and immediate economic losses caused by the significant capital investment. To ensure the District most efficiently used available funds, Carollo s Business Solutions Group conducted a life-cycle cost analysis for the planned meter replacement program. This project provided the optimal replacement implementation strategy based on the meter s age, water demand, and potential revenue loss. Industry standards for meter replacement programs typically assume a useful life of 15 to 0 years. Water meters, as with any measuring instrument, are not able to precisely register the total amount of water consumed. The meters have a limited useful life and are assumed to exhibit performance (i.e., accuracy) degradation over time. Misreads primarily occur at low flow rates ( 0.5 gpm), as there is insufficient volume to recognize the flow. In most cases, these low flow rates are related to leaks in the customer s plumbing fixtures. As part of the analysis, the District performed meter testing to provide data to aid it in determining the effective age for replacement. A sample population of 50 existing meters was tested. Units were selectively chosen to represent those with the highest reads (mileage), meters at their approximate mid life by age, and meters with half the average mileage of all the 1994 KEY Team Member Pierce Rossum (prossum@carollo.com) (oldest) meters. The meters were evaluated at three flow rates: Low Flow (0.5 gpm); Intermediate Flow ( gpm); and High Flow (10 gpm). Contrary to the District s expectations, some of the aging meters showed little accuracy degradation with increased age or mileage and, at times, were shown to be over-reporting. The results were as follows: High-Flow Test (10 cubic feet at 10 gpm). Meters were found to be the most accurate throughout the lifespan, with slight degradation and underreporting with increased age. Intermediate-Flow Test (10 cubic feet at gpm). Meters were found to be accurate in their early years and to over-report with increased age. Low-Flow Test (1 cubic foot at 0.5 gpm). Meter accuracy showed the most variance, with moderateto high-accuracy degradation each year. With these results, the real meter accuracy was analyzed against its actual consumption (Table ). As shown, the 90.6 percent accuracy and a water cost of $.4 leads to a monthly revenue loss of $8.0. By applying the various assumptions to the test meters average monthly consumption, Carollo projected the corresponding impact to revenue (over/under collection) (Figure 1). Given the sample meter flow test results, Carollo extrapolated flow read accuracies over the District s entire customer data set to calculate the estimated district-wide revenue impact due to inaccurate reads for each meter (age and usage). As the radio head retrofit had a 15-year warranty, Carollo ran 15- and 0-year life-cycle cost analyses to estimate the most economical replacement framework. The results revealed the District should replace meters based on a combination of age and usage, as the resulting revenue loss may not justify the full replacement. Flow parameters in this test were calculated Table. Sample Revenue Impact using industry standards for normal Age (years): 18 Monthly distribution. These values represent the Annual Use (hcf): 456 Revenue portions of water flowing through the meter Impact at low, intermediate, and high flow, which Monthly Use (hcf): 38 (Gain) or provide an interpretation of how water is Monthly Loss (ccf): 3.58 Loss consumed in terms of intensity. As shown in Cost per Unit (ccf): $.4 $8.0 Table 1, 1 percent of the flow through the meter is assumed at 0.5 gpm or less; 86 percent of the water flows through the meter at a rate of above 0.5 to gpm; and percent of the flow is recognized as high flow at a rate of gpm Over/(Under) Collection Linear (Over/[Under] Collection) 80 or greater. 0 00, , ,000 These data were designated as the Mileage (CF) 800,000 1,000,000 pattern of use. Figure 1. Age vs. accuracy and corresponding revenue impact Accuracy (%) Accuracy Table 1. Sample Test Meter Pattern of Use Usage Portion Real Accuracy 1% Low % Intermediate % High Real Meter Accuracy 90.6%

5 PROJECTUPDATES Litree PVC Ultrafiltration Membrane Validation Testing for Title Conditional Approval KEY Team Members Zhuang Liu, Ph.D., P.E. Charlie He, P.E., LEED AP Polyvinyl chloride s (PVC s) robust mechanical strength, low cost, and excellent chemical resistance makes it an outstanding material for pipe manufacturing. However, due to the brittle nature of regular PVC, it is rarely used in making membranes because it could result in more frequent fiber breakage and shortened membrane life. A new membrane product made by Litree Purifying Technology Co. Ltd. (China) uses an innovative hydrophilic modified PVC material that overcomes the fiber breakage issues. This product received NSF 61 approval for drinking water applications and is ISO certified. Carollo performed third-party validation testing using protocols approved by the California Department of Public Health (CDPH). The goal was to achieve CDPH Title conditional approval for the membrane model LH V for use in the production of recycled water. This requires the UF membrane permeate turbidity be below 0. NTU for more than 95 percent of the time within a 4-hour period and to not exceed 0.5 NTU at any time. This project was successfully completed through partnerships with multiple agencies, including the Bureau of Reclamation s Yuma Area Office s Water Quality Improvement Center (WQIC), the City of Yuma (testing host), and South Orange County Water Authority (California sponsoring utility). The testing site was located at the City of Yuma Figueroa Avenue Water Pollution Control Facility (FAWPCF). The unchlorinated secondary effluent, with 4 mg/l dissolved organic carbon (DOC), was used as feed water in this testing. WQIC provided operational and maintenance support throughout the project. The testing started in June 01 and was completed in September 01. The validation results demonstrated that membrane performance was reliable and the product water turbidity was consistently below 0. NTU. The CDPH Title conditional acceptance was granted in January 013. New Publication in Sustainability Research Uses Life-Cycle Assessment to Quantify Embedded Water and Energy in Water Treatment In a proof-of-concept research project jointly sponsored by the Water Research Foundation (WaterRF) and the U.S. Bureau of Reclamation, Carollo developed a framework for quantitatively assessing the life-cycle water and energy embedded in water infrastructure. The fundamental technical approach of this work was based on life-cycle assessment (LCA) principles and methods. A water treatment-related life-cycle inventory (LCI) requires life-cycle data for mechanical equipment and construction materials (e.g., concrete, steel, aluminum, plastics, wood), consumable materials (e.g., filter media), and chemicals (e.g., ferric chloride, alum sulfate, sodium hypochlorite), as well as energy usage data for the facility life span. Unfortunately, LCI data for treatment process components and equipment are not readily available. Collecting this data is KEY Team Members Charlie He, P.E., LEED AP (che@carollo.com) Zhuang Liu, Ph.D., P.E. difficult and time-consuming. This limits the development of embedded water and energy accounting analyses, as well as the depth of such efforts. Even with limited readily available data, filling in this type of LCI template is challenging. In this study, Carollo demonstrated an approach to improve the efficiency of LCI data collection. A macro-based Excel spreadsheet model was developed to include the treatment process, related LCI data collected from a currently available LCA database, and information from the Ecoinvent database in SimaPro 7.. Model process modules, such as raw WHAT SNEW water pumping, coagulation/flocculation, sedimentation, and filtration, were populated. The LCI data was linked to common design calculations for each module. This model allows users to select the treatment modules to customize a water treatment facility. It also allowed quick adjustment of key assumptions (e.g., the unit process capacity, as length of the life cycle, unit power costs, and redundancy requirements) and critical design criteria (e.g., surface loading rate, side water depth, retention time, chemical dosage, and power efficiency) for each treatment process. This resulted in a dynamic LCI database that can be easily customized to cover a wide range of flow capacities and operating preferences. The model output provides quantitative evaluations of embedded water, global warming, and other environmental impacts for the selected water treatment facility. The report, including an example model, was published by the WaterRF in February researchsolutions 7researchsolutions

6 8researchsolutions WHAT SNEW Dr. Chao-An Chiu joins Carollo with 5 years of experience in Environmental Engineering research. He received his Ph.D. in Environmental Engineering from Arizona State University in 01, focusing on organic matter transport in the Central Arizona water supply system, and GAC treatment and regeneration technologies. His work involved establishing a dynamic hydraulic model for simulating the distribution of organic carbon in the Salt River watershed and the impact of extreme weather events. In addition, he developed a conceptual, innovative in-situ GAC regeneration system using iron (hydr)oxide nanoparticles and hydrogen peroxide. Chao-An worked closely with the cities of Phoenix, Tempe, Peoria, Chandler, Scottsdale, and Mesa, sampling and The Water Research Foundation (WaterRF) has published the final report for the project entitled Electrochemical Reactor for Minimizing Brominated DBPs in Drinking Water. This project was a joint effort between Carollo and the Castaic Lake Water Agency (CLWA) to study the removal of bromide through the conversion of bromide to bromine using electrochemical reactors and its subsequent volatilization out of solution. When preceded by treatment using electrochemical reactors, bromide removal resulted in the reduction of brominated disinfection byproducts (DBPs) in waters undergoing ozonation with subsequent conventional treatment. This was CRG Spotlight Chao-An Chiu monitoring the water quality (especially taste and odor compounds), and has been giving annual summaries and recommendations in Regional Water Quality Monitoring Workshops since 007. Chao-An is also the primary author of Chapter 4 of the ACS Symposium Series 1048, Trace Organics in Arizona Surface and Wastewaters. His paper titled GAC Removal of Organic Nitrogen and other DBP Precursors (Chiu et al. 01) was selected as the 01 Best Paper for the Research Division of AWWA. Since joining Carollo, Chao-An has been involved in Engineered Biofiltration studies for improved water treatment performance in Phoenix and has developed several hydrologic and chemical modeling tools. He looks forward to bringing his experience in water quality chemistry and hydrology modeling to future Carollo projects. WaterRF Publishes Report on Brominated DBP Minimization in Drinking Water Via Electrochemical Reactors KEY Team Member Adam Zacheis, Ph.D., P.E. (azacheis@carollo.com) the second phase of WaterRF investigations of these reactors, and included the construction and testing of multiple bench reactors (of various anode, cathode, and hydraulic configurations) in addition to the construction of a 10 L/min pilot unit, which was used upstream of an existing ozone and conventional treatment pilot train at CLWA. The pilot unit was used to verify previous research results from both the Phase I WaterRF project and Phase II bench reactors. In addition, the system was used to develop cost estimates for fullscale treatment of a water source with electrochemical reactors and the conceptual design of a 50-gpm demonstration-scale 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 Research group Jess Brown, R&D Practice Director Phone (714) jbrown@carollo.com EDITOR Erin Mackey Design and PRODUCTION Laura Corrington Kim Lightner Matthew Parrott This publication is printed with soy inks on FSC - certified 60% postconsumer waste recycled content.