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Portland Water Bureau

From forest to faucet, we deliver the best drinking water in the world.


1120 SW Fifth Ave, Suite 600, Portland, OR 97204

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LT2 (Long Term 2 Enhanced Surface Water Treatment Rule)

  • The Bull Run Watershed has a variance to the treatment requirements of LT2 The Bull Run source has low levels of Cryptosporidium, resulting in a variance to the treatment requirements of LT2.

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.  


Uncovered Reservoirs

Portland's strategy for compliance with the uncovered finished drinking water reservoir requirements of LT2.

History of Portland's Legal Challenge

Description and documentation legal challenge to LT2.

Documents & Correspondence

This page contains documents and correspondence regarding compliance with LT2.