摘要:

Jane Ceraso is a staff scientist with the Environmental Defense Fund (EDF), a national nonprofit organization founded in 1967. Based in EDF's New York City headquarters, Ceraso works on local and regional water quality and acid rain problems. Her most recent project is an assessment of the effects of acid deposition on reservoirs in the Catskill Mountains, which supply much of New York City's drinking water.

ISSN:0003-150X    

DOI:10.1002/j.1551-8833.1986.tb05836.x

出版商:Wiley    

年代:1986

数据来源: WILEY

摘要:

In a case involving water main extensions, a Pennsylvania appellate court ruled that the extensions were self‐sustaining, noting that if debt service was not averaged and a year‐by‐year analysis of net revenue applied, many beneficial projects would show a loss in the early years even though they would show large revenue gains in the future.

ISSN:0003-150X    

DOI:10.1002/j.1551-8833.1986.tb05839.x

出版商:Wiley    

年代:1986

数据来源: WILEY

摘要:

This discussion about proposed regulations concerning levels of asbestos in drinking water took place June 23, 1986, during A WWA's annual conference in Denver. Participants were: Joseph A. Cotruvo, director of the Criteria and Standards Division of the US Environmental Protection Agency's Office of Drinking Water, Washington, D.C.; James R. Covey, associate sanitary engineer with the New York Department of Health, Albany, N. Y.; Joseph C. Jackson, president of the Asbestos‐Cement Pipe Producers Association, Arlington, Va.; Jeptha A. Wade Jr., vice‐president and chief engineer of the California Water Service Company, San Jose, Calif; and James L. Warden, head of the pipeline section of the US Bureau of Reclamation's Engineering and Research Center, Denver, Colo. Robert S. Bryant, civil engineering associate with the Los Angeles Department of Water and Power, was moderator.

ISSN:0003-150X    

DOI:10.1002/j.1551-8833.1986.tb05841.x

出版商:Wiley    

年代:1986

数据来源: WILEY

摘要:

Water utility personnel engaged in assuring the uninterrupted flow of safe water from treatment plant to tap are constantly asking questions: Is water being contaminated in the pipeline? Is the pipeline efficient? Is there degradation of the pipe material? Is maintenance required? Is the standard for coliform monitoring adequate?

ISSN:0003-150X    

DOI:10.1002/j.1551-8833.1986.tb05842.x

出版商:Wiley    

年代:1986

数据来源: WILEY

摘要:

An informal inquiry of 24 cities about local water system standards resulted in a mini‐survey of criteria used for engineering and planning purposes. Areas covered were standards for sizes and types of pipes used, spacing of pipeline grids, calculations of water use for residences, velocity and pressure of distributed water, costs for pipe laid, head‐loss standards, fire flow standards, and storage requirements. The exchange of such information indicated a need for a nationwide data base for water utility planning and engineering purposes.

ISSN:0003-150X    

DOI:10.1002/j.1551-8833.1986.tb05843.x

出版商:Wiley    

年代:1986

数据来源: WILEY

摘要:

Large doses of alum used for flocculation by the Onondaga County (N.Y.) Water Board caused a buildup of aluminum and silicone oxides on the interior of large distribution pipes. Flow was restricted to the point that supplying demand during peak usage might have become a problem. Planning for a pigging operation was begun in 1983, and the job was successfully undertaken on the Memorial Day weekend of the following year without disrupting production of a major industrial user. The authors describe how the pigging operation was done and the improvement that resulted.

ISSN:0003-150X    

DOI:10.1002/j.1551-8833.1986.tb05844.x

出版商:Wiley    

年代:1986

数据来源: WILEY

摘要:

A water quality complaint received by the city of Tallahasse, Fla., resulted in an investigation that found contamination of a service line caused by gasoline leaking into the soil surrounding the pipe. The service connection to an apartment was the only incidence of the contamination, but levels of 1,2‐dibromoethane were found in one apartment to be 50 times the limit set by the Florida Department of Environmental Regulations. The service line was replaced with copper pipe, which solved the problem.

ISSN:0003-150X    

DOI:10.1002/j.1551-8833.1986.tb05845.x

出版商:Wiley    

年代:1986

数据来源: WILEY

摘要:

Gaining access to residences to read water meters is difficult in Champaign–Urbana, Ill., where unusually large numbers of students and longer‐term residents move in and out of apartments and houses frequently. The Northern Illinois Water Corporation's Champaign–Urbana Division therefore decided to undertake a program to install remote meter‐reading equipment on all meters, beginning in 1981. The economic considerations are discussed as well as the success of the program to date.

ISSN:0003-150X    

DOI:10.1002/j.1551-8833.1986.tb05846.x

出版商:Wiley    

年代:1986

数据来源: WILEY

摘要:

A mathematical model was used to calculate the effects of sample volume and number of samples collected each month on the probability of detecting coliforms in water distribution systems containing various levels of contamination and to compare proposed frequency‐of‐occurrence maximum contaminant level rules with existing microbiological rules. The number of samples examined appeared to have a profound effect on the stringency of a frequency‐of‐occurrence rule, with systems containing borderline levels of contamination more likely to meet the rule if only a few samples are collected each month. It was concluded that a frequency‐of‐occurrence rule with a coliform density limit of 1/100 mL, instead of the current 4/100 mL, would be much closer in stringency to the existing average‐density rule.

ISSN:0003-150X    

DOI:10.1002/j.1551-8833.1986.tb05847.x

出版商:Wiley    

年代:1986

数据来源: WILEY

摘要:

The design and operation of control valves in a closed conduit system require testing of the different flow characteristics of the valves under experimental conditions. Different testing standards and recommended testing procedures have been published for characteristics such as pressure loss and pressure recovery. However, discussion concerning the testing procedures for cavitation and operation limits is scarce. Detailed information is presented on testing procedures and the definitions for the different cavitation limits. The effects of the variables of pressure, size, and flow coefficients are discussed, along with design equations and data for scaling cavitation information with changes in system pressure.

ISSN:0003-150X    

DOI:10.1002/j.1551-8833.1986.tb05848.x

出版商:Wiley    

年代:1986

数据来源: WILEY