AWWA MTC57571

The Long Term 2 Enhanced Surface Water Treatment Rule, developed to fulfillrequirements set forth in the Safe Drinking Water Act (SDWA) Amendments of 1996,proposes new standards for the removal of Cryptosporidium in drinking water plants in aneffort to provide increased public protection from acute illness. The rule proposes aminimum removal/inactivation requirement of 3 log, with additional removal requireddependant upon the source water concentration of Cryptosporidium oocysts.The proposed rule includes a number of technologies, or "tool box", that may be applied toobtain the required level of removal/inactivation. Low-pressure membrane filtration, suchas microfiltration and ultrafiltration, has been included as an appropriate technology for theremoval of Cryptosporidium oocysts.US Environmental Protection Agency is proposing a distinct definition of what may constitute a membrane system, withparticular emphasis on a requirement for a direct membrane integrity test. An acceptabledirect membrane integrity test must have a resolution of 3 microns, and a sensitivity that iscapable of verifying the log credit established for the system.This paper summarizes the proposed requirements for membrane technology and modelsintegrity to demonstrate potential compliance issues for higher levels of Cryptosporidiumremoval/inactivation using membrane systems. The modeling indicates that typicalconfigurations applied to the design of low-pressure membrane filtration may not, in someinstances, provide adequate protection at higher Cryptosporidium removal/inactivation bins.Pre- and post-treatment may be applied with current design configurations to ensurecompliance, or modifications may be made to improve the sensitivity of the testing. Includes 8 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

03/05/2003

Number of Pages:

15

File Size:

1 file , 310 KB