Under the Interim Enhanced Surface Water Treatment Rule, what Giardia log reduction credit is given for conventional treatment with disinfection credits?

Under the Interim Enhanced Surface Water Treatment Rule, what Giardia log reduction credit is given for conventional treatment with disinfection credits?

• A. 4.0 log
• B. 3.0 log
• C. 2.5 log
• D. 2.0 log

Answer: (B)

Log reduction credit is a way to quantify how much Giardia cysts are removed or inactivated by a treatment train. Under the Interim Enhanced Surface Water Treatment Rule, conventional treatment with disinfection credits is assigned a 3.0 log Giardia credit. This reflects the combined effect of substantial removal by filtration and additional inactivation from disinfection, adding up to about three logs of reduction. In practice, you can view it as roughly 2.0 log from effective filtration plus about 1.0 log from disinfection, totaling 3.0 log. This is the standard credit for that treatment configuration, whereas other, more advanced treatments can yield higher credits.

Log reduction credit is a way to quantify how much Giardia cysts are removed or inactivated by a treatment train. Under the Interim Enhanced Surface Water Treatment Rule, conventional treatment with disinfection credits is assigned a 3.0 log Giardia credit. This reflects the combined effect of substantial removal by filtration and additional inactivation from disinfection, adding up to about three logs of reduction. In practice, you can view it as roughly 2.0 log from effective filtration plus about 1.0 log from disinfection, totaling 3.0 log. This is the standard credit for that treatment configuration, whereas other, more advanced treatments can yield higher credits.