Series:

Water Research Foundation Report

9 total works

Cover of Criteria for Valve Location and System Reliability
Due to the lack of availability of proper tools for management of valves, it is very difficult for water utilities to supply water with minimum interruption in case of a water main break. Rules or guidelines for the placement of valves in the distribution system are not well defined, and the impact of valve placement rules on system reliability (i.e., minimizing out-of-service customers) has not been quantified in previous studies.


The objectives of this research were to develop a rationale for valve location using design rules to optimize system reliability, to develop an easy to use program to analyze the efficiency of valves on the reliability of isolation of distribution networks, and to develop a computer model to analyze complicated networks and assist water utilities in minimizing interruption of supply in isolating water main breaks.



The study provides analysis tools and rules for valve placement to allow water utilities to improve system reliability by reducing the number of customers affected by necessary water main isolations. The analysis tools can be used to identify critical valves and provide a quantitative basis for making cost-effective decisions about valve placement. The report includes a CD-ROM that contains the Strategic Valve Management Model (SVMM). The SVMM was developed to provide utilities with a better tool for valve maintenance and system expansion. The program is used to identify segments in water distribution systems and to simulate pipe and valve failure effects on the system.

Cover of Service Life Analysis of Water Main Epoxy Lining
The objectives of this research were to: (1) gather information on historical epoxy lining installations and document the effectiveness of these previously installed liners in protecting cast iron or steel water mains; (2) develop protocols and procedures and conduct accelerated life-cycle tests on epoxy liners to assess their long-term performance; and (3) assess the longevity of early epoxy liner installations for renewal planning.


This study demonstrated that epoxy lining is a viable rehabilitation method for unlined cast iron and steel water mains. For structurally sound water mains with severe tuberculation causing reduced hydraulic capacity and water quality problems, epoxy lining can provide a greater increase in hydraulic capacity than conventional cement mortar linings. When installed properly with appropriate QA/QC procedures, epoxy lining is expected to have a service life of at least 40 to 60 years.

Cover of Assessment of Non-Uniform Corrosion in Copper Piping
Copper pitting that manifests into a pinhole leak greatly shortens the usable lifespan of potable plumbing pipes. The resulting leak can damage housing infrastructure and other valuables or potentially lead to mold growth. Homeowners, in turn, are adversely impacted by pinhole leaks and bear the financial burden associated with premature pipe failure. Unfortunately, factors that cause pinhole leaks and corresponding mitigation strategies are not well understood.


The purpose of this project was to assess the extent and implications of copper pitting and pinhole leaks for residential potable water plumbing systems. Additionally, the project team planned to investigate known and suspected causes of copper pitting and pinhole leaks through case studies at participating communities. Multiple data sources were used to assess the extent of pinhole leaks. National surveys were conducted targeting plumbers, homeowners, businesses, and corrosion experts.



The team also reviewed a database of copper failures spanning 30 years. The mechanistic causes of pinhole leaks were investigated via intensive case studies at participating communities, where hydrological, biological, and aqueous chemical factors were considered. Pinhole leaks have been confirmed nationwide, and about 8.1 percent of homeowners (nationally) have experienced leaks. The total cost of pinhole leaks, including prevention, is $967 million. A number of different mechanisms were identified as the cause of pinhole leaks at participating communities including aggressive water quality, microbiologically-induced pitting, and hydrological factors.



Includes a CD-ROM with Pinhole Leak Case Studies and Surveys

Cover of Occurrence Survey of Boron and Hexavalent Chromium
Only limited information existed about the occurrence of boron and chromium in drinking water sources prior to this project. In addition, chromium speciation in drinking water sources was not well understood. In fact, due to analytical method deficiencies, previous field sampling experiences had resulted in total chromium concentrations less than corresponding hexavalent chromium concentrations. This project specifically addressed the following questions: What are the analytical method challenges and sensitivities for reliable low-level detection of chromium species and boron in drinking water supplies? What are the national occurrence patterns for chromium species and boron in drinking water sources? What is the fate of these compounds through drinking water facilities and distribution systems? This research provides a new baseline of national boron and chromium, total and hexavalent, occurrence in drinking water sources. It also indicates that existing treatment technologies do not effectively remove boron or hexavalent chromium. Originally published by AwwaRF for its subscribers in 2004.

Cover of Implementing a Prototype Energy and Water Quality Management System
The operating environment for water utilities is changing. New information and control systems and operating procedures are required to manage water utility operations. Operations and maintenance managers must pursue improved planning and scheduling methods to reduce costs. Electric deregulation presents an opportunity and a challenge for energy cost reduction. Water quality and supply issues must be managed to maximize system performance and minimize costs. EWQMS systems enable water utilities to better utilize limited resources to provide optimal service to their customers. By planning and scheduling operations processes and integrating the use of data from automated systems, an EWQMS enables utilities to do more with less?just what is needed in the changing business climate. Originally published by AwwaRF for its subscribers in 2003

Cover of Disposal of Waste Resulting from Arsenic Removal Processes
There are a number of treatment techniques that can effectively remove arsenic from drinking water. It is essential for utilities that are in the process of selecting an arsenic removal treatment technology to also identify the types of residuals that would be generated, their expected arsenic concentrations, and pre-treatment strategies that would be required prior to final disposal. This document provides utility guidelines for disposal of residuals containing elevated concentrations of arsenic.Originally published by AwwaRF for its subscribers in 2003 This publication can be purchased and downloaded via Pay Per View on Water Intelligence Online - click on the Pay Per View icon below

Cover of Practical Application of Online Monitoring
Utilities across the USA rely on online monitors to help them track important parameters such as disinfectant residual and particle removal. However, there are no guidelines on how to operate these monitors so that they are consistent and measure as accurately as possible. This study investigated the current uses of all online monitors in plants and their calibration and maintenance procedures in order to gain an understanding of the current industry standards. The purpose of this project was to evaluate how utilities are using and maintaining their online equipment and to provide guidelines for utilities to consider in their online monitoring program. The status of online instrument use in U.S. water utilities was surveyed. The survey was completed by 264 utilities representing 392 treatment plants. Case studies of six utilities were performed to supplement the survey results by recording, in-depth, the instrument uses, maintenance practices, instrument support structure, and supervisory structure as related to online instrument use. In addition, case studies provided online and bench data from their online instruments for analysis. The utilities selected included conventional filtration, direct filtration, lime softening, and unfiltered systems with widely varying source water quality. A sample Standard Operating Procedure (SOP) was developed to provide utilities with guidance in creating SOPs. The findings concerning using volatility as a way of evaluating the performance of online instruments could impact the water industry by providing new techniques to measure online monitor performance and as an early warning system of monitor problems.

Cover of Water Utility Self Assessment for Management of Aesthetic Issues
While water utilities operate their systems primarily to meet mandatory water quality requirements, many experts in the taste and odor field suspect that most drinking water utilities in North America are poorly prepared for taste and odor (T&O) events. The sporadic and transitory nature of T&O events and difficulties associated with their proper identification and response has led many utilities to approach these events with limited or no "tools" available to address recurring problems. The objectives of this study were to (1) assess the preparedness level of North American drinking water utilities for T&O events by creating an on-line survey, (2) develop a decision-tree tool to help utilities identify and manage a T&O event, and (3) develop a self-assessment tool that will allow a utility to identify its strengths and weaknesses regarding T&O preparedness. Almost every water utility has been or will be affected by a T&O event. Currently, no information readily exists for identifying, controlling, or managing T&O events. The decision tree will help utilities identify the source of the T&O event through sensory descriptors. The self-assessment will emphasize a utility?s ability to quickly identify the source of a problem, implement a control strategy, and communicate with its stakeholders. The survey will provide insight on how well-prepared utilities are regarding T&O events.

Cover of Application of Knowledge Management to Utilities
  Typically, data generated by the drinking water industry is used daily to make operational decisions regarding water resource management, water treatment, and distribution strategies. Failure of accurate and timely reporting of some of the data can result in compliance violations, which can be costly and embarrassing for utilities. If managed, aggregated, and stored effectively, the data could help determine management strategies for repeated situations. This study sought to help improve the data management and operations of drinking water utilities.  The four objectives of this study were to: review the state of knowledge management as an industry;           illustrate how knowledge management might be used in a drinking water utility;            review how knowledge management is being applied in utilities;            develop a pilot knowledge management implementation system for a drinking water utility. It is clear that knowledge management tools can address many of the barriers related to water quality issues and facilitate the solutions for drinking water utilities. The primary recommendation from the research team was the development of an Information Bureau whose mission is to make data available, develop the knowledge management infrastructure needed, and be a recognized resource for gathering information.  However, prior to implementation of a knowledge management system, a requirements analysis should be conducted, utility size should be considered, and the recognition of the cultural change that accompanies knowledge management should be recognized. Originally published by AwwaRF for its subscribers in 2003