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.

Plans and Specifications were completed in June and approved by the Department of Ecology.

CIP 1 was advertised for construction and McClure and Sons, Inc, was the low bid at $2,033,578.  Construction will begin in early October as the Notice to Proceed is anticipated to be delivered in late September 2021.



Project Timeline

Item Date
Council Acceptance of Low Bid July 2021
Notice to Proceed Construction September 2021
Construction Completion Deadline December 2022