DEALING WITH THE PAST, MANAGING THE PRESENT, AND PLANNING FOR THE FUTURE Eric Owens, West Basin Municipal Water District, 17140 S. Avalon Blvd, Carson, CA 90746 Email: erico@westbasin.org Phone: 310-660-6223 Shivaji Deshmukh, West Basin Municipal Water District, Carson, CA Christiana Daisy, West Basin Municipal Water District, Carson, CA Abstract West Basin Municipal Water District (West Basin) has been using both microfiltration (MF) and reverse osmosis (RO) for water recycling since the early 1990 s. As a result of this 20 years of experience, and many similar endeavors by others in the industry, membrane treatment systems have shifted from an 'alternative technology' to the treatment technologies of choice for potable reuse applications. During the past 20 years, West Basin has also been quick to adopt and incorporate other advanced treatment technologies into its treatment processes, such as ozone addition as pre-treatment to MF, and hydrogen peroxide and ultraviolet light as polishing for the RO permeate. Despite nearly 20 years of design, construction, and operational experience with water recycling, West Basin recognizes that it has much to learn from an industry that has rapidly evolved over the past two decades. West Basin s recycled water program also includes tertiary disinfected recycled water and MF/RO treatment applications for industrial reuse. The recycled water system has been cobbled together through four expansions of the Edward C. Little Water Recycling plant, the addition of three satellite treatment systems, two distribution pump stations, multiple disinfection stations, over 120 miles of pipelines, to reach approximately 230 customer connections. This paper will discuss the lessons learned by West Basin from 20 years of membrane application, discuss West Basin s current effort to catch up and implement several industry standards, and share how West Basin plans for its future reliability and expansion. Specifically, this paper will review West Basin s past designs, construction and implementation of recycled water facilities including membrane treatment. The paper will review West Basin s current efforts to implement a rigorous asset management program, and efforts to formalize a repair and rehabilitation (R&R) program dedicated to maintaining a highly splintered and aging infrastructure. The paper will also include discussion of future capital improvement projects intended to expand West Basin s recycled water program with new service laterals, customer connections, and membrane treatment projects, all while expanding its overall water portfolio through ocean-water desalination. Background West Basin was formed in the 1940 s and services over 900,000 people living in 17 cities in the 185-square mile service area of coastal Los Angeles County. West Basin purchases imported water from the Metropolitan Water District of Southern California (MWD) and wholesales the imported water to cities and private companies in southwest Los Angeles County. West Basin 1
has been operating a recycled water program since the early 1990 s through a partnership with the City of Los Angeles. West Basin treats secondary effluent from Los Angeles Hyperion Wastewater Treatment Plant (Hyperion) to various effluent qualities for a variety of industrial agricultural, and indirect potable uses. Despite nearly 50 years as a water wholesaler, the recycled water program represented West Basin s first significant investment in vertical and horizontal assets, simultaneously constructing recycled water treatment facilities and a recycled water distribution system. Recycled Water Treatment Process Description Wes Basin s recycled water program includes a secondary effluent pump station, four treatment facilities, more than 100 miles of distribution pipeline, two booster pump stations, and disinfection stations. Constructed in 1994, West Basin has expanded the Edward C. Little Water Recycling Facility (ECLWRF) four times (Phases I V). West Basin has also constructed three satellite facilities including the Chevron Nitrification Facility, the ExxonMobil Water Recycling Facility, and the Juanita Millender-MacDonald Carson Regional Water Recycling Facility. Currently, West Basin produces five distinct recycled water products, including: 1. Tertiary Disinfected Recycled Water for irrigation applications 2. Nitrified Water for cooling tower applications 3. Single-Pass MF/RO permeate for low pressure boiler feeds at oil refineries 4. Double-Pass MF/RO Permeate for high pressure boiler feeds at oil refineries 5. Full Advanced Treatment using ozone, microfiltration, reverse osmosis, ultraviolet light and hydrogen peroxide (advanced oxidation processes, AOP) for injection into the West Coast Basin aquifer as a seawater intrusion barrier. Figure 1 includes a schematic of West Basin s overall recycling program. Additional descriptions of each recycled water facility are included below. Source Water Hyperion is the largest wastewater treatment facility in the Los Angeles Metropolitan area, and is operated by the Bureau of Sanitation in the City of Los Angeles. The City of Los Angeles has operated Hyperion, located adjacent to West Basin s service area, since 1894. Initially built as a raw sewage discharge plant into the Santa Monica Bay, Hyperion has been upgraded over the years to secondary and full secondary treatment. Hyperion treats raw sewerage utilizing coarse bar screens for removal of large debris, as well as sedimentation for grit removal. Primary treatment at Hyperion includes coagulation, oil and grease removal, and solids separation prior to secondary treatment. Secondary treatment uses high-purity oxygen (HPO) for BOD oxidation prior to settling and clarification. Hyperion s full treatment capacity is 450-850 million gallons per day (mgd) and secondary treatment capacity is 450 mgd. The first phase of West Basin s recycled water program included the construction of the Hyperion Secondary Effluent Pump Station at Hyperion Treatment. This pump station currently delivers a firm capacity of 40 mgd to ECLWRF, and will be expanded to 70 mgd by 2017. Edward C. Little Water Recycling Facility The first phase of West Basin s recycled water program included the construction of the ECLWRF in 1995. The facility initially treated Hyperion s secondary effluent with additional tertiary treatment in order to meet California s Title 22 irrigation regulations. Today, this process 2
includes ferric chloride coagulation ahead of high-rate clarification, sand filtration, and disinfection. The early recycled water program also treated secondary effluent with lime clarification ahead of cellulose acetate reverse osmosis (RO) membrane for injection into the seawater intrusion barrier. In 1998, West Basin s Phase II expansion built an advanced recycled water treatment facility using microfiltration (MF) as pretreatment to polyamide RO membranes. These systems were known as the Barrier Treatment System. In 2000, ECLWRF was expanded to supply two grades of water to the Chevron oil refinery, and included microfiltration, first pass reverse osmosis, and second pass reverse osmosis. In 2006, the Barrier treatment process was expanded and advanced oxidation was added to the treatment train, including ultraviolet light and hydrogen peroxide. In 2013, ECLWRF was again expanded, this time including ozone pretreatment ahead of the Chevron and Barrier microfiltration systems, and increasing the capacity of the Barrier treatment system. The Full Advanced Treatment water produced by West Basin is purchased by the Water Replenishment District of Southern California and blended with potable water for injection into the West Coast Basin Seawater Barrier. This injected water has the dual benefit of not only preventing seawater intrusion into the aquifers of the West Coast Groundwater Basin, but also providing replenishment to replace the water that is extracted by drinking water wells. Seawater barriers are a series of injection wells that form a barrier to ensure that the groundwater level near the ocean stays high enough to keep seawater from seeping into a basin. Distribution System West Basin s recycled water program includes more than 100 miles of distribution pipelines, primarily for the tertiary disinfected recycled water. The distribution system also includes two booster pump stations and two chlorine disinfection systems. Satellite Facilities West Basin s recycled water program includes three satellite facilities, where additional treatment occurs to meet refinery customer s specific water quality needs. All three satellite facilities treat tertiary disinfected recycled water with biological nitrification (ammonia reduction for cooling tower application) or MF/RO (TDS reduction for boiler feed application). Chevron Nitrification Facility Nitrification for Cooling Tower Application. ExxonMobil Water Recycling Facility Nitrification for Cooling Tower Application and MF/RO for Boiler Feed Applications. Juanita Millender-MacDonald Carson Regional Water Recycling Facility Nitrification for Cooling Tower Application and MF/RO for Boiler Feed Applications. 3
Figure 1: West Basin s Recycled Water Program Overview Lessons Learned from the Past West Basin has identified many lessons learned during its twenty years history of water recycling. Many of these have been learned the hard way, and could be perceived as obstacles to operating and maintaining a water recycling program. West Basin has categorized these lessons into the following areas: Influent Water Quality Variability Water recycling facility design can be challenging, especially when the source water offers frequent variability. Wastewater effluents can experience concentration swings that range from hourly to annual due to the ebb and flow of residential life or commercial business cycles. If the anticipated oscillations remain consistent enough, designs can be sufficiently robust to achieve production goals and design removals. But as the frequency and duration of these swings worsens due to a variety of environmental and social impacts, it becomes more difficult to predict future variations. There are many contributions to the feed water quality variability, including drought conditions, conservation, and wet weather events. Through each of the five phases of expansion at ECLWRF, designers have had to account for an increasingly variable feed water. West Basin has experienced dramatic swings in constituents of interest such as 4
turbidity and total suspended solids (TSS). Figure 2 includes ECLWRF plant influent trends for turbidity and TSS since 1995. Water Conservation Water conservation has been a trend for more than two decades within southern California and especially in West Basin s service area, where West Basin funds conservation programs and facilitates public outreach to educate the public on water conservation. In times of drought, such as the past 5 years in California, water conservation has increased even more as local and imported water resources are becoming scarcer. This results not only in a highly secondary effluent as described above, but a continual increase in concentrations of concern. For the past several years, this has resulted in elevated levels of turbidity and TSS, ammonia and TDS. Figure 2 includes ECLWRF plant influent trends for ammonia and TDS since 1995. Water Supply Sources Southern California s water supply from the State Water Project (SWP) has been impacted by pumping restrictions resulting from a federal ruling of the Endangered Species Act that requires protection of the delta smelt. Additionally, the persistent drought in northern California has required a shift for imported supplies from SWP to Colorado River sources. Statewide conservation efforts have also resulted in shift from imported to local water sources. All of these changes can result in dramatic shifts in secondary effluent quality. West Basin is currently experiencing unprecedented levels of ammonia and TDS resulting in changes in potable water sources. Aging Infrastructure Instances of equipment and infrastructure failure increase at a rapid rate as facilities age. This can be exacerbated if the materials of construction were based on a water quality from twenty years previous, and concentrations of corrosive constituents such as ammonia or TDS have increased. Capital Improvement projects, repair and rehabilitation (R&R) programs, and operation and maintenance (O&M) programs need to be continuously updated and validated to ensure agency design standards, equipment selection, and performance expectations are suitable for the current conditions. Despite twenty years of operating a recycled water program, West Basin has only recently begun to develop a contemporary asset management program intended to offer a proactive approach to O&M. Additionally, West Basin is in the process of developing and implementing a R&R program in an effort to proactively replace or repair equipment, assets, or treatment processes in an effort to minimize unexpected shutdowns or failures. Regulatory Requirements Regulatory requirements for recycled water have change based on continued research, education and maturation of the industry. Recycled water programs need to have the flexibility to adapt new technologies, treatment processes, or monitoring requirements not only to address feed water quality changes, but also to stay current with the current regulatory requirements. As a part of the Phase IV and V expansions, advanced oxidation was added to the Barrier treatment train to meet regulatory requirements and to ensure destruction of N-Nitrosodimethylamine (NDMA) and other constituents of emerging concern. 5
Operator Certification Water recycling facilities can use both conventional treatment technologies (coagulation, clarification, filtration, disinfection, etc.) and advanced treatment technologies (ozone addition, microfiltration, reverse osmosis, and advanced oxidation). Recycled water treatment operators have to be well versed in a wide array of systems in order to meet the specific goals of their treatment system. However, until recently, operator training and certification has fallen into a grey area somewhere between Wastewater treatment operations and Potable Water treatment operations. The industry as a whole is heading towards better defining the recycled water operator s role and education in the industry. But because West Basin employs both conventional and advanced treatment technologies to produce its five unique qualities, it has been a constant challenge to find new staff that is experienced, knowledgeable, and competent in the variety of treatment processes and systems utilized in the recycled water program. As a consequence, West Basin currently allows its operations staff to be either wastewater or drinking water certified, and relies heavily on internal training to meet the operator s educational needs. Agency Overlaps and Partnerships Creating a new recycled water program or developing capital improvement projects can be a challenge due to regional politics and governmental agency overlap. In West Basin s example, we have strategic partnerships and contractual relationships with the City of Los Angeles Bureau of Sanitation, City of Los Angeles Department of Water and Power, Los Angeles County Sanitation District, County of Los Angeles Department of Public Works, Water Replenishment District of Southern California. West Basin s distribution system extends throughout several different city, county, and water purveyor jurisdictions. West Basin also holds direct contracts with its refinery customers for the delivery of recycled water. West Basin has worked hard to ensure strong relationships with each partner in order to ensure the success of the recycled water program. 6
Ammonia Concentration, mg/l Total Dissolved Solids, mg/l Average Daily Turbidity, NTU Total Suspended Solids, mg/l 50 45 40 Turbidity TSS mg/l West Basin ECLWRF Plant Influent 35 30 25 20 15 10 5 0 6/1/95 2/25/98 11/21/00 8/18/03 5/14/06 2/7/09 11/4/11 7/31/14 50 1400 45 40 1200 35 1000 30 800 25 20 600 15 10 5 Ammonia Total Dissolved Solids 400 200 0 0 6/1/95 2/25/98 11/21/00 8/18/03 5/14/06 2/7/09 11/4/11 7/31/14 Date Figure 2: ECLWRF Plant Influent Quality 7
Managing the Present while Planning for the Future Asset Management During its investigation into asset management, West Basin found that the existing software version was limited in its capabilities with a grossly outdated database. As an example, several Phase I assets long since removed or replaced, were still found in the current database. As a result, West Basin is in the process of implementing an asset management system with the purpose of providing a systematic approach to maintaining, upgrading, and operating West Basin s physical assets and providing guidance towards optimal benefit at a minimal cost. West Basin is taking a phased approach to implementing its asset management system. West Basin first focused on acquiring the best software package for its needs. After careful review, Infor s Hansen 10x software was selected as the platform for West Basin s future asset management program. The next phase of asset management development includes determining appropriate levels of service, hierarchy, and nomenclature, transferring and updating the existing data base, and populating new assets. Extensive staff training will be included during implementation. Capital Improvement Program Reliability Projects To effectively respond to current and potentially long-term drought conditions, imported water uncertainty, and regulatory restrictions, West Basin actively pursues locally supplied water as a viable alternative to ensure a reliable supply of water today and for the future. To meet this objective, West Basin has implemented an aggressive program to find the right solution for the region by doubling conservation efforts, doubling recycled water deliveries, and incorporating ocean-water desalination into West Basin s water portfolio in the future. West Basin continues to take carefully thought-out steps to ensure water reliability while faced with an uncertain future. West Basin intends to address future customer needs, system capacity, and the infrastructure required to potentially double current recycled water deliveries and meet the region s demand. West Basin is initiating projects that will increase the capacity and contribute to the reliability of the recycled water system. These include the expansion of Barrier water microfiltration facilities, the Tesoro Refinery Expansion project, and the Hyperion Secondary Effluent Pump Station Expansion. These large CIP projects will strengthen the reliability of the recycled water system as well as introduce additional revenues through increased sales. West Basin works ceaselessly to find ways in which to partner with potential customers and begin the design and construction of new laterals which will result in increased recycled water demand thereby further lowering our future reliance on imported water. The CIP budget also includes funds for the construction of recycled water pipelines and customer connections that will be funded through a partnership with the United States Army Corps of Engineers or California s Proposition 84 funding. In regards to ocean-water desalination, West Basin has utilized extensive treatment experience, performed multiple technical studies, and has learned from other desalination facilities around the world to develop an approach that will effectively and efficiently manage this resource. West Basin has completed an Ocean Water Desalination Program Master Plan, operated a temporary ocean water desalination demonstration facility (Desal Facility), initiated an Intake Biofouling and Corrosion Study through Metropolitan Water District s (MWD) Foundational Action Grant Program, and began an Environmental Impact Report (EIR) for the proposed full-scale 8
desalination facility. In addition, West Basin has recently initiated a study to investigate the technical feasibility of subsurface seawater intake systems. Table 1: West Basin CIP Reliability Projects CAPITAL IMPROVEMENT PROGRAM Total Project Budget Fiscal Year 2015-2016 Budget Reliability Projects 1 Tesoro Refinery - Capacity Expansion Project 23,282,000 2,200,000 2 RO CIP Waste Discharge 4,350,000 3,500,000 3 Ocean Water Desalination Program 423,685,910 3,678,000 4 Hyperion SE Pump Station Expansion 16,862,159 11,237,000 5 Water Quality Facility Improvements 1,121,000 1,121,000 6 RW Laterals & Connections 7,567,085 6,167,344 7 Barrier Production Increase 27,500,000 11,000,000 8 Nitrified Water Alkalinity Process Upgrades 2,010,000 1,980,000 9 Universal MF Pilot 350,000 150,000 Reliability Projects Total: 506,728,154 41,033,344 R&R Program West Basin s has implemented a Rehabilitation and Replacement (R&R) Program to identify components of West Basin s recycled water infrastructure that are in need of repair or replacement. The R&R Program helps to ensure that equipment is properly maintained and replaced as necessary to maintain the ongoing operation of West Basin s treatment facilities. R&R projects are currently managed by West Basin s Engineering and Operations staff. The projects must be closely coordinated to minimize facility outages and prevent contractor conflicts while multiple projects are concurrently taking place at West Basin s various facilities. West Basin hired an outside consultant to coordinate with West Basin and its contract operator, Suez, to identify and prioritize R&R projects, develop project Scopes of Work, develop project budget estimates, determine project resource requirements, develop a master program schedule and evaluate potential project delivery methods. The culmination of the consultant s efforts will be a comprehensive R&R Program schedule, with detailed scopes of work and cost estimates for each individual R&R Project. The R&R Program schedule will allow staff to determine how best to deliver the R&R projects moving forward. Over 150 R&R projects totaling approximately $23 million have been identified for completion through Fiscal Year (FY) 2017-18. Additional R&R projects will be rolled into the program as they are identified, prioritized, scoped and costestimated. Conclusions Despite more than twenty years of operational experience with recycled water treatment and distribution, West Basin is only recently formalizing asset management and R&R programs in order to minimize downtime, reduce O&M costs, and ensure reliable production of high quality recycled water for its customers. Through an extensive CIP reliability program, West Basin will continue to reduce reliance on imported water through additional recycled water production and 9
an ocean water desalination program. West Basin will refer to its past successes and pitfalls with recycled water to ensure the success of ocean water desalination. 10