Miguel Barcenas, City of San Luis Obispo Interim Utilities Deputy Director of Engineering Kathi Robinson, Mimiaga Engineering Group/Carollo – Construction Management Services Chris Lehman, City of San Luis Obispo Water Resource Recovery Facility (WRRF) Supervisor

The SLO Mystery: What Caused a Sudden Drop in Nitrification?

Nitrification Loss at SLO Raises Questions About Causes and Cures
Jim Force, Resource Recovery
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Last September, nitrification came to a sudden halt at the Water Resource Recovery Facility in San Luis Obispo. While plant staff has come up with a couple of potential solutions, and the plant is nitrifying again, the real cause and cure remain somewhat of a mystery. As a result, Chris Lehman, SLO facility supervisor, advocates a broader discussion among plants experiencing similar issues.

“This was different from nitrification issues we’ve had in the past,” says Lehman. “Something happened. We went a whole month without nitrifying, and we’ve never gone that long before. The biology simply stopped working. There was some underlying issue we couldn’t explain.”