Groundwater Replenishment System Research Articles

X-ray Absorption Spectroscopy Reveals Mechanisms of Calcium and Silicon Fouling on Reverse Osmosis Membranes Used in Wastewater Reclamation

Reverse osmosis (RO) is widely employed to provide clean water from nontraditional sources (e.g., seawater or municipal wastewater). One of its key challenges is membrane fouling, which leads to reduced flux and increased operational costs. Despite its practical relevance, fundamental understanding of membrane fouling is limited. Toward this end, we investigated calcium (Ca) and silicon (Si) fouling under real RO feed conditions using μ-X-ray fluorescence (μ-XRF) mapping and μ-X-ray absorption near-edge fine structure (μ-XANES) spectroscopy. These techniques are distinctly suited to identify the spatial distribution and (local) chemical speciation of foulants, thereby providing unique insight into the mechanisms of fouling under realistic conditions. Specifically, we investigated RO membranes harvested from a pilot-scale RO system operated at the Orange County Water District (OCWD) Groundwater Replenishment System (GWRS) Advanced Water Purification (AWP) Facility, which received the same feed water as the full-scale plant. Both Ca and Si were found to be abundant in the fouling layer. Despite the use of a commercial antiscalant to inhibit mineral formation, several Ca minerals were present in the fouling layer as minority species, including sulfates, phosphates, and carbonates; most of these minerals were found in particles that were aligned with the feed spacer used to separate the membranes. In contrast, organic-bound Ca and silica occurred across the entire membrane. Our work provides novel insight into the synergistic mechanism of RO fouling by Ca, Si, and organics on RO membranes.

Orange County Completes Groundwater Replenishment System

OpflowVolume 49, Issue 5 p. 36-36 Departments Orange County Completes Groundwater Replenishment System First published: 05 June 2023 https://doi.org/10.1002/opfl.1834Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article. Volume49, Issue5June 2023Pages 36-36 RelatedInformation

Groundwater recharge through shallow groundwater recharge system by infiltration ponds in Fai Kwang Sub-district, Phayao Province of Thailand

The shallow groundwater recharge at an area scale in Fai Kwang Subdistrict, Chiang Kham District, Phayao Province, Thailand aim to apply of the groundwater replenishment system to solve the problem of drought and insufficient water for consumption using by shallow groundwater recharge system through the concrete circle in pond integrating with using technology to manage surface water with the GIS system and geophysical surveys for evaluating the potential of groundwater resources to access information on land use, soil conditions, water resources. The groundwater recharge system at depth 12 m and water was replenishment occurs flow from pubic pool collected water converted to water filtration and pumping average water volume of 3.54 m3/hr to solve the problem of surface water quality for water supply in tap water production of Siwilai Village, Fai Kwang Subdistrict, Phayao Province, which enabled people in the area to used water for 200 homes. The social return on investment (SROI) was 59.23%, reducing water purchase and medical expenses due to water quality impact. The study results have led to the creation of water management policies and the application of information and innovations for drought resolution. Measures and requirements for using public water sources for consumption collecting income for the maintenance of the village's water supply system.

Groundwater Recharge to Address Seawater Intrusion and Supply in an Urban Coastal Aquifer

The Orange County Water District (OCWD) was created in 1933 by the California Legislature and tasked with managing water resources in Orange County. As a part of its strategy to fight seawater intrusion and guarantee a reliable groundwater supply in the basin, OCWD built a recycled wastewater facility that treats wastewater received from the Orange County Sanitation District and recharges the water into the basin through injection wells and infiltration ponds. OCWD’s first recycled wastewater facility, Water Factory 21, began operating in 1975 and was replaced in 2008 by the Groundwater Replenishment System (GWRS). Recharged water not serving as a barrier for seawater instruction is pumped by local water districts and municipalities (referred to as “producers”), who pay a pumping fee to OCWD. Water provided by GWRS is both more reliable and less expensive for the producers than water acquired from other sources, including imported surface water. In responding to the recognized threat of seawater intrusion, OCWD owes its success to creatively enabling recharge through the development of novel source water. OCWD’s broad purview and authority to manage groundwater, combined with its effective implementation and long-term stewardship of the recharge program as it has evolved over many years, have enabled innovation in MAR using treated wastewater.

Ecological effects of wastewater treatment modifications on infauna communities off the coast of Orange County, California

The Orange County Sanitation District (OCSD) is a public agency that provides treatment of wastewater for residents in Orange County, California. The final effluent characteristics at OCSD have been altered in the last 18 years due to the ~20-fold increase of sodium hypochlorite usage for disinfecting waste streams from 2002 to 2010, implementation of the Ground Water Replenishment System (GWRS) in 2008, and conversion to full secondary treatment, together with a major reduction of sodium hypochlorite usage in 2011. This study analyzed infauna data gathered from 1994 to 2016 at the zone of initial dilution (ZID) and reference stations located on the San Pedro Shelf to assess the effects of these treatment process changes on biota in the receiving water. Impacts to the infauna community within the ZID were observed during the period of high chlorine usage, including the increased proportion of the pollution tolerant polychaete Capitella capitata complex from 6.2% in 2003 to nearly 60% in 2010, the lowest Infaunal Trophic Index score in 2009, and the highest Benthic Response Index score in 2006. The degradation of the infauna community in the ZID was correlated with chlorination and was coincidental with the initiation of the GWRS. The infauna community at the ZID recovered rapidly after the implementation of full secondary treatment as indicated by the significant reduction of the relative abundance of C. capitata complex from 59.8% in 2010 to less than 0.1% after 2012, and by the markedly improved community health index scores. This study demonstrated the composition and biointegrity of the infauna community at the ZID varied in response to changes in the wastewater treatment process. Caution should be exercised at wastewater treatment plants when relatively higher dosages of sodium hypochlorite are used over a multi-year period, as this may negatively impact aquatic biota in the receiving water.

Degradation of contaminants of emerging concern by UV/H2O2 for water reuse: Kinetics, mechanisms, and cytotoxicity analysis

Advanced oxidation using UV and hydrogen peroxide (UV/H2O2) has been widely applied to degrade contaminants of emerging concern (CECs) in wastewater for water reuse. This study investigated the degradation kinetics of mixed CECs by UV/H2O2 under variable H2O2 doses, including bisphenol A, estrone, diclofenac, ibuprofen, and triclosan. Reverse osmosis (RO) treated water samples from Orange County Water District’s Groundwater Replenishment System (GWRS) potable reuse project were collected on different dates and utilized as reaction matrices with spiked additions of chemicals (CECs and H2O2) to assess the application of UV/H2O2. Possible degradation pathways of selected CECs were proposed based on high resolution mass spectrometry identification of transformation products (TPs). Toxicity assessments included cytotoxicity, aryl hydrocarbon receptor-binding activity, and estrogen receptor-binding activity, in order to evaluate potential environmental impacts resulting from CEC degradation by UV/H2O2. Cytotoxicity and estrogenic activity were significantly reduced during the degradation of mixed CECs in Milli-Q water by UV/H2O2 with high UV fluence (3200 mJ cm−2). However, in GWRS RO-treated water samples collected in April 2017, the cytotoxicity and estrogen activity of spiked CEC-mixture after UV/H2O2 treatment were not significantly eliminated; this might be due to the high concentration of target CEC and their TPs, which was possibly affected by the varied quality of the secondary treatment influent at this facility such as sewer-shed and wastewater discharges. This study aimed to provide insight on the impacts of post-UV/H2O2 CECs and TPs on human and ecological health at cellular level.

Hydrothermal synthesis of photoactive nitrogen- and boron- codoped TiO2 nanoparticles for the treatment of bisphenol A in wastewater: Synthesis, photocatalytic activity, degradation byproducts and reaction pathways

Hydrothermal technique was employed for the synthesis of N- and B-codoped TiO2 at different atomic percentages and calcination temperatures (350 and 400 °C). Borane tert-butylamine complex was used as a novel precursor for the dopant atoms. The photocatalytic activities of catalysts were evaluated for destruction of bisphenol A (BPA) spiked in clean water and in secondary treated wastewater influent (SWI) collected from the Groundwater Replenishment System GWRS (Orange County, CA, USA), the world's largest water purification system for indirect potable reuse. Results of X-ray photoelectron spectroscopy (XPS) revealed the incorporation of N and B atoms onto TiO2 lattice via substitution of O and/or Ti, and interstitial incorporation mechanisms. Carbon doping (graphite-like carbon; O-C = O) was also evidenced from XPS spectra. X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HR-TEM) revealed pristine TiO2 and all doped TiO2 existed in anatase structure. The anatase phase of catalysts was further confirmed by simulation of selected area electron diffraction (SAED) of the catalysts and reported anatase TiO2 using the simulation software CrysTBox (v 1.10). Among all prepared catalysts, 2.0NBT-350 (N + B = 2.0%, calcination = 350 °C) possessed the smallest particle size (12.9 nm), largest BET surface area (108.5 m2/g) and highest visible-light absorption (i.e., λ > 400 nm). Simulated solar light/2.0NBT-350 system exhibited the maximum removal of BPA (0.1 μM) at the optimum catalyst dose of 0.8 g/L in clean water, over three consecutive degradation reuse cycles without any noticeable decrease in its photocatalytic activity. BPA was also successfully removed in SWI water, however with slower kinetics due to hydroxyl radical quenching effect of dissolved organic and inorganic species present in the SWI matrix. Degradation byproducts were identified by LC/Q-TOF-ESI-MS analysis. Six byproducts were found in the reaction mixture, with two compounds were newly identified in the current study. BPA oxidation routes comprised successive BPA hydroxylation, elimination of aromatic ring, ring opening, and cyclization of aliphatic compounds. This study is a promising demonstration for controlled design and synthesis of photocatalysts useful for environmental applications, especially for the treatment of BPA in wastewater effluents.

Newspaper Coverage of Potable Water Recycling at Orange County Water District’s Groundwater Replenishment System, 2000–2016

Water planners in water-strapped communities in the western United States and beyond increasingly consider potable water recycling an important water management strategy. Although potable water recycling can increase an otherwise limited urban water supply, the threat of public or political opposition often looms large. This paper examines newspaper coverage of the most widely celebrated potable water reuse project in the world—the Groundwater Replenishment System (GWRS) in Orange County, California, USA. The case study examines the coverage of GWRS contained in local, national, and international newspapers during an era of significant investment and repeated expansion. Despite the potential controversy associated with drinking recycled wastewater, there was no negative newspaper coverage of GWRS from 2000–2016. Much of the coverage was mundane, however several articles embraced infrastructure and technology as key to developing new water resources while protecting public and environmental health. Although potable water recycling is presented as an innovative solution capable of solving several problems at once, a close analysis reveals that recycled water may not fulfill the promise of an uninterruptible urban water supply.

Evaluating the Latest Low-Pressure Membrane Technologies for the Groundwater Replenishment System

Evaluating the Latest Low-Pressure Membrane Technologies for the Groundwater Replenishment System

Orange County Groundwater Replenishment System Expansion Raises Reliable Southern California Water Supply

Finished Water is a photo feature that profiles working operators and utilities in the news, particularly new and renovated facilities.

Advancing indirect potable reuse in California

While indirect potable reuse (IPR) has been used in southern California (USA) since the 1970s, the commissioning of the 265-megalitre-per-day Groundwater Replenishment System (GWRS) in Orange County (California) showed the region's commitment to utilizing reuse as a major source of potable water augmentation. The treatment process used at GWRS has become the benchmark on which California regulations were based and which other IPR facilities are measured against. As the cities of Los Angeles and San Diego move forward with their own IPR programs, they have commissioned pilot-scale and demonstration-scale projects to build on the lessons learned at the GWRS and to aid in developing future projects that are efficient, effective, and publicly supported. This paper will discuss the technical approaches being evaluated in these projects and the lessons learned in the operation of the existing full-scale facilities.

Identifying, Evaluating, and Implementing Antiscalants in RO Reuse Applications

AbstractThe Orange County Water District (OCWD) operates a 70-mgd RO system as part of the Groundwater Replenishment System (GWRS), an advanced wastewater purification facility. Each of 15 5-mgd RO units consists of a three-stage array, operating at 85 percent recovery. As part of the operating strategy, antiscalant and pH suppression are used to limit third-stage precipitation of sparingly soluble mineral salts. Identifying successful antiscalants is extremely challenging. A variety of antiscalants with varying chemistries and capabilities present opportunities for optimizing RO processes, pricing, dosage, and pH adjustment. Recognizing the potential savings in RO pretreatment chemical cost, OCWD began antiscalant pilot-scale trials in 2009. However, failure to identify an effective product led to the trial's cancellation. Concurrently, the GWRS RO facility began experiencing third-stage permeability loss in all 15 RO units because the antiscalant was ineffective. This article discusses fast-track testin...

Improving Performance and Reducing Costs in Reclaiming Secondary Municipal Waste

AbstractThe Orange County Water District of Southern California conducted side-by-side testing of the latest reverse osmosis (RO) membrane technology and membranes currently operating in the district's Groundwater Replenishment System. The new RO elements were installed in a satellite vessel attached to the first stage of an existing three-stage train. New membrane performance was monitored for seven months and compared with the performance of the existing membranes, which had been operating for two years. Construction of the new elements included a thicker (34-mil) spacer, leading to less differential pressure loss and less fouling potential. The new elements had the same membrane area as the existing elements and, therefore, could be operated at the same flux and flow. This article compares operating data to demonstrate the new membrane's improved performance, RO membrane chemistry, and element design. The data demonstrate the new membrane's potential for reducing operating costs in a full-scale system.

UV/AOP A Key Part of the Groundwater Replenishment System

UV/AOP A Key Part of the Groundwater Replenishment System

Orange County's Groundwater Replenishment System: Water Quality Monitoring and Facility Expansion in the Face of Changing Regulations

Orange County's Groundwater Replenishment System: Water Quality Monitoring and Facility Expansion in the Face of Changing Regulations

Developing an RO Cleaning Strategy for Minimized Energy and CIP Costs

Orange County (Calif.) Water District (OCWD) performed an economic analysis to determine the most effective cleaning interval for the reverse osmosis (RO) membranes in its Groundwater Replenishment System (GWRS), which consists of 26 microfiltration (MF) cells operating polypropylene membranes at 20 gfd (34 lmh) and more than 90 percent recovery. The MF system has a filtrate capacity of 86 mgd (325 MLD). Each cell houses 608 submodules. An RO system consists of 15 5-mgd (19 MLD) trains for a total of 70 mgd (265 MLD) RO permeate capacity. The RO trains operate at 85 percent recovery and maximum permeate flux of 12 gfd (20.4 lmh). Each train houses 1,050 8- × 40-in. high-productivity RO membrane elements in a 78:48:24 array. OCWD staff analyzed optimum operation intervals between cleanings based on the energy required to operate each train.

Converting BOD to Nitrification/Denitrification in Same Reactor While Maintaining Capacity

Converting BOD to Nitrification/Denitrification in Same Reactor While Maintaining CapacityThe Orange County Sanitation District (OCSD) modified their activated sludge operation from biochemical oxygen demand (BOD) to nitrification-denitrification (NDN) mode to reduce ammonia discharged and sent to the Groundwater Replenishment System (GWRS) operated by Orange County Water District. Full scale verification tests were conducted following conversion to NDN. The conversion to NDN was...Author(s)J.B. NeethlingBruce WilleyAdam NicholsMichelle HetheringtonDave HeinzRon WadeWendy SevenandtSourceProceedings of the Water Environment FederationSubjectSession 103: Developments in Nitrogen RemovalDocument typeConference PaperPublisherWater Environment FederationPrint publication date Jan, 2011ISSN1938-6478SICI1938-6478(20110101)2011:8L.6627;1-DOI10.2175/193864711802793317Volume / Issue2011 / 8Content sourceWEFTECFirst / last page(s)6627 - 6637Copyright2011Word count130Subject keywordsNitrification-DenitrificationSecondary TreatmentConvert BOD to NDN

Recycled Water Consider a Drought‐Proof Water Supply

This article discusses treating previously wasted sewer water at three advanced recycled water treatment facilities (AWTFs) that include: Groundwater Replenishment (GWR) System, Orange County (California) Water District (OCWD); Water Replenishment District (WRD), Southern California's Leo J. Vander Lans Water Treatment Plant; and, South District Water Reclamation Plant (SDWRP), Miami‐Dade Water and Sewer Department (MDWASD). AWTF benefits and challenges are discussed, along with critical agency management support, the importance of preliminary design in setting parameters for an entire project, lessons learned from testing and initial operation, and start‐up concerns.

The Groundwater Replenishment System: The Largest Indirect Potable Reuse Plant in the United States

The Groundwater Replenishment System: The Largest Indirect Potable Reuse Plant in the United States

Building on Lesson Learned for Expanding the Next Phase of the Groundwater Replenishment System

Building on Lesson Learned for Expanding the Next Phase of the Groundwater Replenishment System