The International Stormwater BMP Database (BMP Database) is a long-term project that began in 1994 through the vision of members active in the Urban Water Resources Research Council of the American Society of Civil Engineers (ASCE) and leadership of the U.S. Environmental Protection Agency (EPA). Funded for many years by EPA, the project is now supported by a coalition of partners including the Water Environment Research Foundation (WERF), Federal Highway Administration, American Public Works Association, as well as ongoing support from ASCE's Environmental and Water Resources Institute (EWRI). The project is multi-faceted and includes guidance on BMP monitoring, design parameters and watershed characteristics to report with BMP monitoring studies to facilitate analysis and performance analysis protocols. The cornerstone of the project is a publically available database containing performance information for over 450 BMP studies, with 500 anticipated by late 2011. During 2008–2010, major revisions to the Database were completed to enhance user friendliness, incorporate Low Impact Development (LID) practices and site designs, refine analysis protocols, and develop new performance summaries. All project materials are publically available for download at www.bmpdatabase.org. This paper provides a condensed summary of key findings from performance analysis completed during 2010 and early 2011, representing the most comprehensive analysis to date of the BMP Database performance data in several key areas. Five technical summaries were developed focusing on BMP performance for fecal indicator bacteria, nutrients, volume reduction, total suspended solids (TSS), and metals. Each paper provides a discussion of the current regulatory context for the constituent, a summary of data included in the database, a detailed assessment of adequacy of the data for purposes of analysis, discussion of unit treatment processes relevant to the constituent, and statistical analysis and evaluation of BMP performance for the data sets. Data are summarized graphically and are provided in spreadsheets that can be used for independent analysis. Based on the analysis, recommendations regarding BMP selection, limitations on use of the data, and recommendations for additional research are provided.

As recommended, culvert entrances in urban areas should be protected with a rack or a grate because urban flood flows are quick, concentrated, and fast. Safety around storm-water facilities is an increasing concern for the public. Many forensic cases indicate that a trash rack at the entrance can prevent a human body from being washed into the culvert pipe, but on the other hand, a trash rack increases the flow velocity and results in a pinning force on the human body landed on the rack. While having a trash rack at a culvert entrance has the potential to result in a pinning force and to accumulate trash/debris, the public safety benefit of a trash rack in preventing a person from being drawn into an underground conduit outweigh the risks of the potential pinning force and/or trash/debris blockage. The conventional approach can only provide the total external force acting on a culvert-rack system, including the reaction forces from the wing walls and the rack with or without blockage. This study presents a new method of superimposition that can solve the external forces one by one progressively. Results from the case study indicate that the hydrostatic force due to the high headwater in front of the culvert entrance is mostly balanced by the reaction force from the wing walls. The pinning force on the submerged trash rack is mainly the response to the change in the flow momentum force. In comparison, the pinning force is much smaller than the total external force. A pinning force is a normal force on the rack surface. The effort to escape from being pinned on the trash rack is to overcome the friction along the rack surface.

Low Impact Development (LID) strategies are being encouraged throughout the country as an approach to reduce potential adverse impacts of development on receiving streams. Many questions exist regarding how well various LID strategies perform in different settings, just as similar questions have been raised regarding performance of traditional stormwater best management practices (BMPs). Over a decade ago, American Society of Civil Engineers (ASCE) Urban Water Resources Research Council (UWRRC) members worked to develop a set of standardized monitoring and reporting protocols for traditional BMPs and establish a master database for the purpose of evaluating BMP performance and the factors affecting performance. This effort culminated in the International Stormwater BMP Database (www.bmpdatabase.org), which contains data for approximately 360 BMPs and continues to operate as a clearinghouse for stormwater BMP data and performance analyses. During 2008–2009, the Stormwater BMP Database project expanded to better integrate LID into its monitoring, reporting and analysis protocols through the support of a coalition led by the Water Environment Research Foundation, the U.S. Environmental Protection Agency, the Environmental and Water Resources Institute of ASCE, the Federal Highway Administration, and the American Public Works Association. This paper provides an overview and progress report on the LID-focused effort, including the following topics: 1. New monitoring guidance for LID studies. 2. An overview of recent changes to the stormwater BMP database to better accommodate LID studies, including LID studies at the site development level (multiple distributed controls) and individual LID techniques. 3. A summary of LID studies currently included in the database, including bioretention, green roofs, permeable pavement, biofilters and other practices.

Attainment of U.S. Environmental Protection Agency (EPA) recreational water quality criteria and state water quality standards for bacteria presents significant challenges to water resource managers in communities throughout the U.S. From a regulatory perspective, many communities are faced with Total Maximum Daily Loads (TMDLs) for bacteria, typically for either E. coli or fecal coliform. For local governments responsible for National Pollutant Discharge Elimination System (NPDES) Municipal Separate Stormwater (MS4) permits, this issue can be particularly challenging and many questions arise with regard to whether stormwater best management practices (BMPs) can reduce bacteria in stormwater runoff. Many valid questions exist regarding how attainable current stream standards are and what measures are truly meaningful in reducing bacteria in streams and in development of meaningful TMDLs. This paper provides a synopsis of Best Management Practice (BMP) performance data provided for bacteria in the International Stormwater BMP Database and discusses implications of these findings for stormwater managers. Findings from analysis of these data are used to provide some recommendations regarding the types of efforts that are expected to provide meaningful results in terms of water quality management policy and bacteria reduction in stormwater and receiving waters. Implications for development of TMDLs with the potential to provide real improvement of water quality is also discussed.

More then a decade ago, members of the Environmental and Water Resources Institute's (EWRI's) Urban Water Resources Research Council (UWRRC) identified a need to gather sufficient technical design and performance information to improve urban stormwater Best Management Practice (BMP) selection and design so that local stormwater problems can be cost-effectively addressed. As a result, the International Stormwater BMP Database Project was initiated. The U.S. Environmental Protection Agency (USEPA) initially funded the project through the UWRRC of ASCE via multiple grants, and in 2004, the project transitioned to a more broadly supported coalition of partners led by the Water Environment Research Foundation (WERF), and including the American Public Works Association (APWA) and the Federal Highway Administration (FHWA), as well as ASCE and USEPA. While the long-term vision of the project has remained the same, many significant improvements to the database have been made. This paper provides an overview of the overall database project for those unfamiliar with the project and identifies major changes that have been made for those familiar with the early stages of the effort. This paper provides an overview of the resources now available from the www.bmpdatabase.org website. Key aspects of these resources include enhanced tools to track BMP performance through improved data entry spreadsheets and a significantly revised project website. Additionally, an overview of the studies contained in the database, which now includes over 340 BMP studies, is provided. Several examples of how regional and state organizations have adopted the database to track their own BMP performance and improve reporting associated with BMP performance studies are provided. The presentation accompanying this paper will provide additional examples of how the database can be used as a tool for a broad range of entities involved in stormwater management and research or affected by National Pollutant Discharge Elimination System (NPDES) permits, such as public works administrators and engineers, state transportation departments, consulting engineers, and university researchers. Due to significant growth of the database and improvements in data analysis and summary products, the database is a scientifically-based resource that now offers relevant information and tools to all of these users.

Republished from two practical guidance documents on solids transport velocities in sanitary sewers: One dated August 1, 1967, Environmental Engineering Department, Central Engineering Laboratories, FMC Corporation, and the other title Technical Memorandum No. 7, from November 16, 1967, the ASCE Combined Sewer Separation Project, New York, New York.

Technical Memorandum No. 4. Republished from material presented on May 1, 1967, at the ASCE Combined Sewer Separation Project, New York, New York.

Technical Memorandum No. 11. Republished from material presented in January 1970 at the ASCE Urban Water Resources Research Program, New York, New York.

Technical Memorandum No. 7. Republished from material presented in February 1969 at ASCE Urban Water Resources Research Program, New York, New York.

The purpose of this paper is to answer the question of why it is so difficult to obtain reliable performance data for urban stormwater best management practices (BMPs) such as retention/detention ponds, wetlands, swales, infiltration devices, proprietary devices, and others. Our assessment of this question is based on extensive experience developing, implementing, and conducting stormwater monitoring programs, as well as development and oversight of the U.S. Environmental Protection Agency (USEPA)/American Society of Civil Engineers (ASCE) National Stormwater BMP Performance Database, on behalf of ASCE's Urban Water Resources Research Council. The paper begins with a list of factors that contribute to the difficulty of BMP monitoring, and concludes with a review of representative problems that we have experienced when reviewing BMP performance data sets that have been submitted to the National BMP Performance Database Clearinghouse for integration into the database.

Development in drinking water watersheds poses many water quality challenges. The level of water quality protection required goes beyond typical best management practices (BMPs) that are used for development in non-drinking water watersheds. To assess the treatment strategies that will protect the water quality of the reservoir two elements must be considered: (1) the allowable pollutant loading for the reservoir and (2) the loading from the development given a variety of treatment strategies. Water quality models serve as a tool for evaluation of both of these elements in the planning stages of a development. This paper presents a water quality model developed for evaluating pollutant loading from development projects in the Aurora Reservoir watershed in the Denver metropolitan area in Colorado, USA. A major developer in the watershed, Laing/Village Homes (LVH); has worked closely with the City of Aurora (Aurora) to develop a water quality treatment system for the Southshore development that will limit pollutant loadings to the reservoir to a level that will protect the water quality of this drinking water supply. LVH has developed a model for evaluation of pollutant loadings from the development; Aurora is working to determine allowable pollutant loadings to the reservoir.

The Urban Water Resources Research Council of the American Society of Civil Engineers, under a cooperative agreement with the US Environmental Protection Agency, released Version 1.0 of the National Stormwater Best Management Practices (BMP) Database to the stormwater management community in 1999. The product included a loaded database of 71 BMPs, as well as data entry software for standardized reporting of BMP test data. In conjunction with the database, the project team developed BMP performance evaluation protocols and applied them to the data contained in the initial database. Since the initial database release, 42 new BMP data sets have been added to the database, which is now accessible via the Internet at www.bmpdatabase.org along with associated data evaluation reports and other project documentation. A national stormwater BMP data clearinghouse continues to screen and post new BMP data to the database, as well as respond to inquiries from the public. An overview of both of the database software and results of the data evaluation are provided in this paper.

Denver's 1969 Urban Storm Drainage Criteria Manual has long been recognized as one of the leading drainage design manuals in the United States and internationally, with a distribution list outside of Denver numbering in the thousands. In 2000 to 2001, the Urban Drainage & Flood Control District (District) and 39 cities and counties within the District updated and expanded the original manual. The resulting reference represents another major step forward in the urban drainage area.

This paper summarizes and synthesizes, from the authors' perspective, the key themes and observations that emerged during the August 19–24, 2001 conference held in Snowmass, Colorado entitled: Linking Stormwater BMP Designs and Performance to Receiving Water Impact Mitigation. The objective of the conference was to discuss and debate what we know and do not know about the linkages between BMP designs and their performance and their ability to mitigate receiving water impacts of urbanization.

Development projects in the high-altitude mountain environment of the Rocky Mountains often require innovative best management practices (BMPs) due to challenging runoff conditions, the relatively short growing season, vegetation and wildlife habitat considerations, and the high level of water quality of receiving waters. This paper discusses the unique challenges of development in the mountain region of Colorado and describes a variety of BMPs and stormwater/dewatering discharge management strategies that have been successfully employed on development projects. Case studies are presented of approaches for addressing runoff from snowmelt; shallow groundwater; soil erodibility, mobilization, and suspension; water chemistry; and regulatory requirements related to water quality and wetlands protection. These case studies provide examples of structural BMPs including an integrated treatment system for stormwater runoff and construction dewatering discharges utilizing multi-stage treatment, including alum-polymer addition for enhancing sedimentation of fine suspended clay particles. As an example of a state-of-the-technology non-structural BMP, the Town of Silverthorne, Colorado's Waterbody, Wetland, and Riparian Protection Regulations is examined. These regulations, which were adopted in 1999, are intended to protect the beneficial functions and values of wetlands through requiring a buffer zone around all waterbodies, wetlands, and riparian areas, ranging in width from 7.6 to 38 meters (25 to 125 feet) depending on implementation of BMPs and buffer zone functions. One of the first large development projects in Silverthorne to come under these regulations, the 3-Peaks Golf Course and residential development, is examined to illustrate application of these new regulations.

The purpose of this study is to evaluate claims of excess heat generation during water electrolysis. Several cells were constructed and operated similarly to low-current-density cells described in the Literature. All produced excess heat as defined and calculated in the literature reports, but the production of excess heat could be readily terminated by the introduction of various barriers to the migration of hydrogen and oxygen. Remarkably, published reports of excess heat fail to disprove the presence of decreased faradaic efficiency (e.g., current that oxidizes H-2 or reduces O-2) Or systematic calorimetric errors. Illustrative examples of both problems are given. Thus, failure to rule out prosaic explanations probably invalidates all the currently available reports of excess heat in both light water-Ni/Pt and heavy water-Pd/Pt cells. There is no compelling evidence that excess heat is of a nuclear origin in such electrolytic cells.