Central San owns and operates a wastewater treatment plant with a low solids retention time (SRT) activated sludge secondary treatment process. Low SRT secondary effluent can be challenging to filter and MF/UF vendors typically specify operation on a higher SRT fully nitrified secondary effluent. The goals of the pilot were to establish sustainable operating conditions for both MF/UF and RO as well as demonstrate that the product water would be fit for purpose for non-potable industrial reuse (low TDS, ammonia, and metals) at two nearby refineries. The pilot provided critical information to confirm that non-potable refinery reuse is achievable without upstream secondary treatment upgrades. Sustainable MF/UF fluxes up to 40 gfd with 2.5 mg/L ferric chloride as Fe and up to 30 gfd with 10 mg/L aluminum chlorohydrate coagulants were observed. The RO operated sustainably for almost three months and did not require a CIP.

This paper is a case study on the implementation of a new dissolved air flotation (DAF) system to replace a secondary gravity clarifier in the activated sludge process at a petroleum refinery. Technology selection, process design, start-up issues, chemical conditioning requirements, fullscale performance, and lessons learned are presented. The DAFs met the effluent total suspended solids (TSS) objectives and the site’s goal of providing process equipment redundancy within the limited footprint available.

HRPDC developed a pilot project that installed a regional network of water level sensors to monitor roadway flooding. The sensors redirect drivers away from roads that are flooded, saving commute time, and avoiding potential property damage caused by driving through dangerous high water. The data can also inform emergency response actions such as ambulance routing. Long term, the sensor data allows us to analyze trends and understand when tides, wind, and rainfall create the most flooding. This improves our ability to predict the frequency and severity of flooding and evaluate investments in flood mitigation. The approach of this pilot project is to use real-time data to make informed decisions and build a smart network of available driving conditions.

The City of Madison, Wisconsin was selected for a smart utility demonstration project. Intel® provided a grant to INTERA Incorporated and Isle Utilities to review current technologies and data streams for visual interpretation. The United States Geological Survey developed and installed the sensor network. The City of Madison provided the locations of chronic flooding, access to the right-of-way to install the sensors, and staff to help facilitate the work. Installation of the sensors began in April 2022. Since then, 35 sensors, collecting data at 5-minute increments, have been installed. Setting up a new system, such as a smart utility, in a municipality like the City of Madison has its unique challenges. Challenges include integration of the system with existing City Information Technologies, checking the system for risk and legal implications, and understanding the right people and agencies to alert at the right time.

The Metropolitan Water District of Southern California (Metropolitan) and Los Angeles County Sanitation Districts (LACSD) are jointly exploring the potential of implementing the Pure Water Southern California (PWSC) program, which would include building an Advanced Water Treatment Facility (AWTF) capable of producing a 568 MLD (150 mgd) of purified water at LACSD’s Joint Water Pollution Control Plant (JWPCP) in Carson, CA. A series of studies conducted by both agencies have identified the application of a tertiary membrane bioreactor (tMBR) as a promising approach to provide nitrogen removal downstream of the JWPCP. This pilot study focused on evaluating tMBR design concepts with an emphasis on demonstrating successful operation of nitrification-denitrification (NDN) tMBR concepts. This study showed that NDN operated in a pre-anoxic configuration either utilizing supplemental carbon or primary effluent provides a promising approach for PWSC and potential future ocean discharge requirements for JWPCP

Results of a technoeconomic assessment for optimization upgrades to a ZLD WWT system at a combined cycle facility in the western US will be presented. Due to changes in total dissolved solids content of freshwater makeup, the ZLD system historically underperformed relative to design and required discharge to an emergency pond undersized for sustained flow. Capital investment options to reduce volume of concentrated brine as cost effectively as possible were assessed for suitability.

This study developed capital and operation and maintenance (O&M) cost estimates and curves to remove and destroy per- and polyfluoroalkyl substances (PFAS) from municipal water resource recovery facility (WRRF) effluent and biosolids. Class 5 cost estimates (-30%/+50%) for the assumed design bases were estimated based on vendor quotes and standard design practices for combinations of technologies pre-screened to be both commercially applied and effective at PFAS separation and/or destruction. Three treatment alternatives were developed for 0.1 to 10 MGD of tertiary treated WRRF effluent and two treatment alternatives were developed for 1.0 to 10 dry tons per day (dtpd) of dewatered WRRF biosolids. Estimated costs for a 10 MGD facility producing 10 dptd biosolids are approximately $79 to $250 million in capital costs and $50 to $20 million in annual operating costs, including consideration of all alternatives developed. Cost per mass of targeted PFAS removed (7 compounds for WRRF effluent and 9 compounds for WRRF biosolids) ranged from $370,000 per pound of PFAS removed from a 50 dptd WRRF biosolids treatment facility to $8 million per pound of PFAS removed from a 0.1 MGD WRRF effluent treatment facility. These costs do not include any retrofits needed to add tertiary treatment upstream of PFAS separation processes for WRRF effluent or to achieve 15%-25% solids content prior to PFAS destruction processes for WRRF biosolids.

This paper discusses an alternative, non-codified approach (as opposed to fully prescribed approaches) to wastewater effluent UV disinfection system design that allows for pragmatic, cost effective designs to be developed. New Zealand’s ‘effects based’ environmental legislation, as it applies to wastewater effluent discharges, provides for a license applicant to demonstrate the actual and likely effects (including public health) of their proposed activity and to propose measures to mitigate those effects. Quantitative Microbial Risk Assessment has increasingly become adopted in New Zealand as a means or a tool by which: a) the likely effect attributable to a particular activity in or near the environment, can be assessed, b) pragmatic discharge pathogen limits can be established, c) the disinfection system design parameters can be established d) systems developed can be tested and monitored for effectiveness. Significant savings can be made (but not always) and a fair outcome is typically achieved.

PUB, Singapore’s National Water Agency, is implementing Tuas Water Reclamation Plant (Tuas WRP), which will be one of the most revolutionary facilities of its kind in the world with resource recovery in the form of NEWater and energy. Two of the key objectives of Tuas WRP are to: Minimise energy usage and maximise energy recovery. Harness synergies from water-energy-waste nexus by integrating used water and solid waste treatment under a single facility: Tuas Nexus. This paper will address how the design achieves these objectives.

Although most developments in tubular membrane design have focused on membrane material, Swirltex recognized an opportunity to focus on membrane hydraulics and the aspects that contribute to a membrane's performance. The objective was to keep impurities away from the membrane while boosting its surface velocity. Injecting gas to increase velocity and altering the buoyancy of pollutants produces a high-velocity annular flow when combined with centrifugal flow. Buoyancy-based membrane filtration combines multiple strategies to improve the filtration process's performance significantly. Swirltex technology enables higher performance without increasing energy consumption. This patented flow pattern keeps impurities away from the membrane's surface, decreasing fouling and resulting in significant cost savings. Tubular membranes' enhanced efficiency enables them to be used in previously ineffective generated water applications.

To support the upgrade and replacement of existing coarse and fine mechanical screens at a large wastewater treatment facility treating a combined sewer system, field data was collected to analyze the solids capture effectiveness of different screen size and type combinations. Each facility’s wastewater influent is different, and different types of screens perform differently at different facilities. This paper shows the value of collecting screen performance field data to better inform screening facility equipment upgrade decisions.

Low carbon, energy recovery projects at wastewater treatment plants are typically discretionary and require a return on investment to execute. As carbon and energy markets evolve, long-term project payback is subject to variability in incentive pricing and can reduce confidence in decision making. Two case studies of recent biogas utilization projects in California are presented to demonstrate a strategy for driving forward the 'right' projects in a dynamic funding and regulatory environment. The first case study describes the City of Roseville's Pleasant Grove Wastewater Treatment Plant, which completed construction of a grant-funded biogas upgrading to renewable natural gas for onsite vehicle fueling, microturbines, and codigestion. The second case study covers the Fairfield-Suisun Sewer District Wastewater Treatment Plant Bioenergy Generation Project, which is installing a new IC engine. Both case studies provide perspective on how to align bioenergy projects with grants and incentives to maximize return on decarbonization investments and increase confidence in decision making.