摘要:

Today, unlined cast‐iron water mains account for the majority of pipe in most distribution systems across the country. However, even if their structural integrity is adequate, their carrying capacity will have been reduced in most instances. As corrosion occurs, the inside of the pipe will begin developing pits as material is removed and then tubercules are formed. To restore the carrying capacity of unlined water mains and prevent further internal corrosion, a method has been developed whereby the mains are cleaned by removing all tubercules, and then a cement‐mortar lining is applied to the pipe walls to prevent the formation of new tubercules. The article describes the process used to clean and line cast‐iron pipelines. A table gives approximate costs for cement mortar lining versus pipe replacement.

ISSN:0149-8029    

DOI:10.1002/j.1551-8701.1992.tb00274.x

出版商:Wiley    

年代:1992

数据来源: WILEY

摘要:

The Surface Water Treatment Rule (SWTR), which took effect December 30, 1990, may affect small systems. If surface water is used, it must be disinfected (as used here, surface water also includes groundwater under the direct influence of surface water). Also, all surface waters must be filtered unless exacting conditions are met. Depending on the specific situation in a small system, the requirements of the rule took effect January 1992 or will take effect June 1993. This article will focus on the steps a system may take if the utility must treat its water to comply with the SWTR.

ISSN:0149-8029    

DOI:10.1002/j.1551-8701.1992.tb00275.x

出版商:Wiley    

年代:1992

数据来源: WILEY

摘要:

The article describes and diagrams a package plant for water treatment, including coagulation/flocculation, settling basin, and mixed‐media filter. Typical applications, advantages of using a package plant, and maintenance are briefly mentioned.

ISSN:0149-8029    

DOI:10.1002/j.1551-8701.1992.tb00276.x

出版商:Wiley    

年代:1992

数据来源: WILEY

摘要:

The article describes and diagrams the slow sand filtration process. Construction, maintenance, some design parameters, and advantages of slow sand filtration are briefly mentioned.

ISSN:0149-8029    

DOI:10.1002/j.1551-8701.1992.tb00277.x

出版商:Wiley    

年代:1992

数据来源: WILEY