Change Order Number One Purchase Order for Ferric Chloride Use South Shore Water Reclamation Facility Commission Agenda Item # 9

Ferric Chloride (FeCl3) Use at SSWRF Veolia used FeCl3 between 2008 and 2012. Used for phosphorous removal Provided benefit of additional BOD removal in primary clarifiers Reduced BOD loading to aeration system Potential improved plant performance Reduced aeration demand

FeCl3 Use at SSWRF Between 2009 and 2012, Veolia gradually reduced use of FeCl3 Substituted ferrous chloride (FeCl2):~1/3 cost of FeCl3 Since 2016, SSWRF has had challenges meeting plant capacity and effluent quality Change from FeCl3 to FeCl2 is one differing condition

Previous Short Term Pilot Test MMSD and Veolia conducted a short-term pilot to feed FeCl3. Short durations at different dosage rates of both FeCl3 and FeCl2. Saw improved BOD removal in primary clarifiers with FeCl3 as compared to FeCl2.

Proposed 3 Month Test To better understand all impacts, now propose a 3 month FeCl3 test. Change other operational conditions at SSWRF to be similar to 2008-2010 operations. Isolate impacts of changes in operations from changes in characteristics of wastewater influent. Determine advantages and disadvantages to treatment process and plant operations.

Commission Request Staff/VW initiated 3-month test in mid-May. District paying incremental cost of test, totaling $336,960. Initial purchase order issued to VW using ED Authority: $149,760. Request to authorize change order in amount of $187,200 for remaining amount.

QUESTIONS?