WWTP CIP 1 pH Control



The Monroe WWTP's current NPDES Permit includes new pH limits on the plant effluent beginning 1/1/2023.  The current facility is not capable of achieving the new limits consistently or reliably.  The City has selected Kennedy Jenks Consultants to perform the design for the CIP 1 modifications allowing the City to achieve compliance.  The Washington State Department of Ecology has established a timeline of submittals ensuring the City completes the modifications in time for the enforcement of the effluent pH requirements.  Plans and Specifications for CIP 1 are due for submittal on 12/31/2020.

CIP 1 includes Sodium Hydroxide (NaOH) addition to the plant effluent, Magnesium Hydroxide (MgOH) handling improvements, RAS chlorinating system, Mixed Liquor Re circulation controls, and aeration basin baffling.  These modifications will ensure the facility will maintain reliable compliance moving forward.

This project has a contract amount of $305,979 budgeted through Sewer Capital.

Project Timeline

Item Date
Council Authorization February 2020
Notice to Proceed March 2020
Design Deadline December 2020