The Long Term 2 Enhanced Surface Water Treatment Rule (LT2 Rule) (Reference 8.1) requires public water systems (PWSs) that use surface water or ground water under the direct influence (GWUDI) of surface water to monitor their source water (influent water prior to treatment plant) for Cryptosporidium and/or E. coli, and turbidity for a limited period (40 CFR paragraph 141.701). In support of the monitoring requirements specified by the rule, three documents have been developed to provide guidance on monitoring and reporting data under the LT2 Rule to the affected PWSs and the laboratories that support them. This manual provides guidance on the following aspects of the LT2 Rule: Section 1: Overview of the rule's monitoring requirements; Section 2: Establishing a Cryptosporidium laboratory contract; Section 3: Sampling location and schedule guidance; Section 4: Guidance on collecting and shipping LT2 monitoring samples; Section 5: Guidance on submitting historical data ('grandfathering'); Section 6: Understanding Cryptosporidium data and analyses; and Section 7: Understanding E. coli data and analyses.

"February 2006." "EPA 815-R-06-005." Includes bibliographical references.