Wet Weather Flow Management Research Articles

Current and future approaches to wet weather flow management: A review.

Sewers can become hydraulically overburdened during high-intensity precipitation resulting in untreated water entering receiving streams. Combined (CSOs) and sanitary sewer overflows (SSOs) cause adverse public health and environmental impacts as well as management challenges for many wastewater utilities. This novel review presents information regarding wet weather flow regulation, impacts, and current management methods, and offers ideas for future approaches in the United States. Currently, storage followed by conventional municipal water reclamation facility treatment after precipitation events is often employed. Stand-alone alternative technologies include high-rate solids removal, rapid disinfection, filtration, and green infrastructure. However, most current stand-alone approaches do not address soluble BOD5 or emerging contaminants in stormwater and wastewater. As the needs for wet weather flow management change, future approaches should include a goal of zero overflows and achieve effluent quality as good as or better than conventional treatment. To help achieve zero overflows and complete treatment, the "peaker facility" concept is proposed. The peaker facility often remains idle but treats excess flow when needed. Considering the challenges of remaining idle for long periods, starting up quickly, and handling high flows, chemical oxidation may be an applicable peaker facility component. However, more research and development are needed to determine best practices. PRACTITIONER POINTS: Combined (CSO) and sanitary sewer overflows (SSOs) pose both environmental and public health risks as untreated water is discharged into lakes and rivers during high-intensity rain events. Current stand-alone approaches for managing or treating CSOs focus on particulate BOD/COD and solids removal, and do not typically address soluble BOD or emerging contaminants in stormwater and wastewater (including pathogens). New wet weather policies and regulations encourage more holistic approaches by wastewater utilities, and future approaches should include a zero-overflow goal for all CSOs and SSOs. To help achieve zero overflows, the concept of the "peaker facility" is proposed. Chemical oxidation may be an applicable component of peaker facilities for its short detention time and ability to remove, oxidize, or inactive water impairment-causing contaminants.

Ground Truthing Oakland WWTP and Pump Station Flow Meters for Improved Peak Wet Weather Flow Management and Process Control City of Topeka, Kansas

Ground Truthing Oakland WWTP and Pump Station Flow Meters for Improved Peak Wet Weather Flow Management and Process Control City of Topeka, Kansas

Wet Weather Flow Management by In-Stream Storage

Wet Weather Flow Management by In-Stream Storage

A Case Study in the Holistic Evaluation of Wet Weather Flow Management Options for Large Scale Facilities

A Case Study in the Holistic Evaluation of Wet Weather Flow Management Options for Large Scale Facilities

Wet Weather Flow Management: Planning Challenges and Framework

Wet Weather Flow Management: Planning Challenges and Framework

Improving Wet Weather Flow Management at Water Resource Recovery Facilities: The Need for New Perspectives

Improving Wet Weather Flow Management at Water Resource Recovery Facilities: The Need for New Perspectives

Preparing for a Rainy Day – Overview of Treatment Technology Options for Wet-Weather Flow Management

Successful wet-weather flow management requires a multi-pronged approach. Planners and designers should consider a wide variety of source control, conveyance, and treatment alternatives to provide the optimum long-term solution for each watershed. Municipal utilities now have a larger variety of feasible treatment alternatives than ever, and many of today’s stateof-the-art technologies were not available a generation ago when most of North America’s water quality regulations and policies were crafted. Significant advances have been made since then, both in treatment technologies and in the profession’s understanding of wet-weather problems. Many of these “new” treatment technologies have been in operation for over a decade, proving their capabilities. This paper discusses many of these technologies, their potential advantages and disadvantages, and how each might fit into an existing treatment strategy and contribute to a utility’s water quality goals.

Water, Water Everywhere! - Overview of Sustainable Collection System Strategies for Effective Wet Weather Flow Management

This paper provides an overview and case study of sustainable collection system strategies for effective wet weather flow management. The goal is to encourage engineers, planners, and designers developing wet weather improvement plans to take a holistic approach to wet weather facility planning that includes all system components (collection system, treatment facilities, and private service lines/connections). Principles and guidance for collection system management in the 21 st century that were recently developed and published by both the Water Environment Federation and the National Association of Clean Water Agencies are highlighted. In light of the current regulatory and economic climate, utilities must stay focused on their primary mission of managing water quality to minimize risks to public health and the environment while at the same time balancing user rates and customer’s level of service expectations. This paper discusses strategies that will allow utilities to achieve these objectives.

Innovative Approaches for Urban Watershed Wet-Weather Flow Management and Control

Innovative Approaches for Urban Watershed Wet-Weather Flow Management and Control

Leveraging Technology to Provide an Implementable and Sustainable Wet Weather Flow Management Solution for the Wilson Creek RWWTP: A Case Study in the Application of the 2005 Draft Policy on Peak Flow Diversions and the Resulting Regulatory Interactions

Leveraging Technology to Provide an Implementable and Sustainable Wet Weather Flow Management Solution for the Wilson Creek RWWTP: A Case Study in the Application of the 2005 Draft Policy on Peak Flow Diversions and the Resulting Regulatory Interactions

Analyzing wet weather flow management using state of the art tools

Optimal secondary clarifier performance is crucial to meet treatment requirements, especially when treating peak wet weather flows (PWWFs), to prevent high effluent suspended solids (ESS) concentrations and elevated sludge blankets. A state-of-the-art computational fluid dynamic (CFD) model was successfully used as a design and diagnostic tool to optimize performance for municipal wastewater treatment plants subject to significant PWWFs. Two case studies are presented. For Case Study 1, the model was used to determine the number of secondary clarifiers that will be necessary to treat future PWWF conditions for a plant under design. For Case Study 2, the model was used to identify modifications that are currently being made to increase the clarifier capacity for handling PWWF.

Getting More Out of Secondary Clarifiers for Wet Weather Flow Management using State of the Art Tools

Getting More Out of Secondary Clarifiers for Wet Weather Flow Management using State of the Art Tools

PEAK FLOW TREATMENT ALTERNATIVES EVALUATED FOR THE EUGENE-SPRINGFIELD WATER POLLUTION CONTROL FACILITY, OREGON

PEAK FLOW TREATMENT ALTERNATIVES EVALUATED FOR THE EUGENE-SPRINGFIELD WATER POLLUTION CONTROL FACILITY, OREGONA comprehensive facilities plan was developed for the Metropolitan Wastewater Management Commission (MWMC) in 2004 and included an evaluation of the regional wastewater treatment facilities serving the Eugene-Springfield (E-S) metropolitan area. A previous study, the 2001 Wet Weather Flow Management Plan (WWFMP), modeled the collection system, determined what rainfall dependent infiltration and...Author(s)M.G. NoesenDan LaffitteShawn ClarkRobert SprickTroy McAllisterGlen DaiggerSourceProceedings of the Water Environment FederationSubjectSession 5A: Municipal Wastewater Treatment Processes: Wet Weather Management in Wastewater Treatment FacilitiesDocument typeConference PaperPublisherWater Environment FederationPrint publication date Jan, 2005ISSN1938-6478SICI1938-6478(20050101)2005:16L.487;1-DOI10.2175/193864705783867963Volume / Issue2005 / 16Content sourceWEFTECFirst / last page(s)487 - 505Copyright2005Word count314

Receiving Water Response to a Master Plan for Wet Weather Flow Management Developed for the City of Toronto

Abstract The City of Toronto has development a Wet Weather Flow Management Master Plan incorporating a new philosophy in wet weather flow management where rainwater is recognized as a resource. Wet weather flows are to be managed on a watershed basis, and a hierarchical approach to wet weather flow management is to be used, starting with at source, followed by conveyance and finally end-of-pipe control measures. The study area extended across the City of Toronto, encompassing six major watersheds and the waterfront. The Plan development followed the planning principles of Ontario's Environmental Assessment Act and incorporated broad public and agency consultation. A series of 13 objectives was identified and grouped into four major categories: water quality, water quantity, natural areas and wildlife, and sewer system. An innovative approach was used which integrated hydrologic, hydraulic and water quality predictions from land-based, watershed and lake models, respectively, to assess the effectiveness of various strategies. The receiving water response indicated that source controls and conveyance controls were insufficient to achieve the receiving water objectives of the Plan. This was only possible through the implementation of a comprehensive set of measures consisting of: source controls, conveyance controls, end-of-pipe controls, basement flooding protection works, stream restoration works, shoreline management, enhanced municipal operations and an enhanced public education and community outreach program. Overall benefits expected through the Plan include: swimmable waterfront beaches, control of combined sewer overflows in compliance with legislative requirements, basement flooding protection, protection of the City's infrastructure from stream erosion, restoration of degraded local streams and aquatic habitat and the reduction of algal growth along the waterfront, and improved stream water quality in area watercourses. The cost of the Plan over the 25 years is estimated to be $1.047 billion with an additional $233 million in operational and maintenance costs.

Wet-Weather Flow Management in the Great Lakes Areas of Concern

Abstract Under the Government of Canada's Great Lakes Program, the Great Lakes Sustainability Fund and its predecessor programs (the Great Lakes Cleanup Fund and the Great Lakes 2000 Cleanup Fund) were established to implement cleanup actions and strategies that would contribute to the restoration of beneficial uses in environmentally degraded areas (known as Areas of Concern) in the Great Lakes basin. The Great Lakes Sustainability Fund is administered by Environment Canada on behalf of eight Government of Canada departments. Contributing to impaired beneficial uses are municipal wastewaters generated from the urban centres in the Great Lakes Areas of Concern. These municipal wastewaters include treated sewage and wetweather discharges of combined sewer overflows and stormwater runoff. This paper provides an overview of the Municipal Wastewater Program of the federal government's Great Lakes Sustainability Fund and highlights the progress made to date under the program towards wet-weather flow management and the Program's role in developing and demonstrating sustainable approaches and technologies in the Great Lakes Areas of Concern.

Management of rainfall-related environmental risks in urban area

Rainfall brings urban residents both benefits, such as water resources, but also adverse risks such as flooding. Additionally, it has been recognized that wet weather run-off discharges pollutants and transfers chemicals and pathogen bacteria into the aquatic ecosystem. This causes not only deterioration of water quality but also environmental pollution risk. Both the flood risk and environmental pollution risk are treated here as ‘rainfall-related environmental risks’. Although these two kinds of risks are quite different in their characteristics, the main purpose of urban wet weather flow management is how to decrease these risks. Furthermore, these risks have a similar background which is concerned with both the urban structure and the life-style of urban residents. Recently, flood disaster has occurred in the Japanese urban area with increasing frequency causing damage due not only to rainfall intensity, but also the vulnerability of urban structures against heavy storms. Although there has been urban area expansion and a decline in substrate permeability, wet weather flow management in Japan is aimed simply to drain the increased run-off volume quickly. As for the management of hazardous chemicals which might be discharged together with rainfall run-off, this has not been implemented sufficiently. It is necessary to develop a methodology to reduce rainfall-related environmental risks in urban wet weather flow management. In this paper, the possible risk management process and control options of rainfall-related risks will be discussed after a summary of both the similar and differing points between inundation risk and environmental pollution risk. As a result, it is deemed necessary to operate a scheme to raise the rainfall-related environmental risk perception level of urban residents to ensure their participation in risk management.

Comparison of the pollutant loads in dry and wet weather runoff in a southern California urban watershed

This research compares the relative contributions of potential contaminants discharged in dry weather flow (DWF) and wet weather flow (WWF) from the highly urbanized Ballona Creek watershed (BCW) in southern California using empirical and deterministic models. These models were used to compare the loading of the following pollutants: total suspended solids, biochemical oxygen demand, total nitrogen, total inorganic nitrogen, total Kjeldahl nitrogen, total phosphorus, copper, lead, arsenic, nickel, cadmium, and chromium. The results indicate DWF contributes approximately 10-30% of the total annual flow discharged from Ballona Creek. The annual DWF volume was fairly consistent; the variation in DWF percentage contribution was dependent on the highly variable volume of WWF. The relative contribution to the annual pollutant load varied considerably between each pollutant. In general, the DWF load was found to be significant, especially in years with lower precipitation totals. The results from this investigation have identified the relative relationship between DWF and WWF loads in the BCW and will aid in the decision-making process during the development of an integrated DWF-WWF management plan and allocation of water pollution control funds between DWF and WWF management.

Research Needs in Urban Wet Weather Flows

The results of a national assessment of research needs in urban wet weather flow management are presented. Three interrelated categories of urban wet weather flow management are discussed: combined sewer overflows, sanitary sewer overflows, and urban stormwater discharges. The initial compilation of wet weather flow research needs totaled 154 research projects, which was later reduced to 69 higher‐priority research projects for which detailed literature reviews were compiled. From this group, 26 topics were selected as priority research topics. Within this paper, the results of the assessment were organized into the following ten categories:(1) sources and monitoring; (2) receiving water effects; (3) other effects; (4) management; (5) models and decision support systems; (6) watershed management linkages; (7) regulatory policies and financial aspects; (8) source controls; (9) collection system controls; and (10) storage/treatment systems. A summary of the authors' views on research needs within each category is provided. An expenditure of an estimated $20 to $40 million per year in the U.S. is needed to address the identified research needs.

都市雨水に起因する環境リスクマネジメント

Rainfall brings urban residents both blessings, such as water resources, and inundation risk. Recently, it is recognized that wet weather flow discharges pollutant load and transfer chemicals and pathogen bacteria into aquatic ecosystem. Wet weather flow causes not only deterioration of water quality but also environmental pollution risk. The authors think that rainfall brings about negative influences and risks, including inundation, on this social environment. Therefore, the authors will call inundation risk and environmental pollution risk “rainfall related environmental risks”. Although these risks are quite different in their characteristics, to decrease these risks is main purpose of urban wet weather flow management. Furthermore, these risks have similar background concerned with urban structure and life-style of urban residents. In this paper, the authors will summarize resembling and different points of these risks. In addition, risk management process and control options of rainfall related risks will be discussed.

Historical Development of Wet-Weather Flow Management

The management of wet-weather flow (WWF) is necessary to maintain the quality of urban water resources. Throughout history, strategies have been implemented to control WWF for many reasons, including flood and water quality control, aesthetic improvement, waste removal, and others. A comprehensive literature review has been conducted to determine past strategies and to revisit the historical developments of WWF management. Understanding these past strategies and the development of WWF-management systems over time will aid current and future generations in their WWF-management efforts. This paper summarizes the historical literature review, highlighting the development of WWF management from ancient times to the present. The relationship between past developments, the current state, and the future of WWF management is addressed by identifying several lessons learned.