The Long Term 2 Enhanced Surface Water Treatment Rule, developed to fulfill
requirements 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 an
effort to provide increased public protection from acute illness. The rule proposes a
minimum removal/inactivation requirement of 3 log, with additional removal required
dependant upon the source water concentration of Cryptosporidium oocysts.
The proposed rule includes a number of technologies, or "tool box", that may be applied to
obtain the required level of removal/inactivation. Low-pressure membrane filtration, such
as microfiltration and ultrafiltration, has been included as an appropriate technology for the
removal of Cryptosporidium oocysts.
US Environmental Protection Agency is proposing a distinct definition of what may constitute a membrane system, with
particular emphasis on a requirement for a direct membrane integrity test. An acceptable
direct membrane integrity test must have a resolution of 3 microns, and a sensitivity that is
capable of verifying the log credit established for the system.
This paper summarizes the proposed requirements for membrane technology and models
integrity to demonstrate potential compliance issues for higher levels of Cryptosporidium
removal/inactivation using membrane systems. The modeling indicates that typical
configurations applied to the design of low-pressure membrane filtration may not, in some
instances, provide adequate protection at higher Cryptosporidium removal/inactivation bins.
Pre- and post-treatment may be applied with current design configurations to ensure
compliance, or modifications may be made to improve the sensitivity of the testing. Includes 8 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 310 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 15 |
| Published : | 03/05/2003 |
