An Introduction to LT2

The Long Term 2 Enhanced Surface Water Treatment Rule (LT2) was promulgated by the federal Environmental Protection Agency (EPA) to “reduce illness linked with the contaminant Cryptosporidium and other disease-causing microorganisms in drinking water.”

There are two major requirements of the LT2 rule that apply to Portland’s drinking water system:

• Provide additional Bull Run source water treatment to specifically address Cryptosporidium – The Portland Water Bureau does not treat for Cryptosporidium; the State of Oregon issued Portland a variance for the source water treatment requirements of LT2 in accordance with federal and state law. 

• Cover, treat or replace uncovered finished drinking water reservoirs – the Portland Water Bureau is constructing additional storage capacity, allowing the uncovered reservoirs to be taken off-line

The City is continuing to work with the Oregon Congressional delegation and the EPA to pursue relief from the uncovered finished drinking water reservoir requirements of the LT2 rule. The City is seeking assistance from the delegation in obtaining the same consideration from EPA as New York City to evaluate alternative compliance options.

The City also advocates that EPA revise the source water monitoring requirements of the LT2 rule to incorporate recently developed genotyping methods for any detected Cryptosporidium species to provide more relevant public health information to water customers.