Award Contract S 04012 C 01 Sludge Dewatering

Award Contract S 04012 C 01 Sludge Dewatering Filter Press Controls Upgrade at SSWRF Commission Agenda Item #4

Biosolids Processing & SSWRF Filter Presses • District must process biosolids each day • Biosolids composed of microorganisms and digested sludge • Normal operation: biosolids processed at JIWRF • During JIWRF biosolids processing outages, dewater biosolids using 4 operating filter presses at SSWRF 2

Sludge Dewatering Filter Press 3

Filter Press Dewatering • Uses pressure filtration to separate liquid from solids • Liquid filtrate returned to plant influent for treatment • Concentrated solids or dewatered sludge called sludge cake • Goal of process is to produce dry sludge cake while minimizing filtrate solids content 4

Filter Presses • Installed early 1990 s • Controlled by PLCs - specialized computers that automatically control pumps, valves, and equipment • Existing PLCs out of production for more than 15 years and no longer supported • Failure of PLC requires specialized parts only available from secondhand market 5

Filter Presses • Essential that filter presses be available for solids processing • To ensure reliability of sludge dewatering process, staff recommends replacing filter press control system • Proposed contract scope: replace PLCs, indicator lights, and operator interfaces 6

Filter Press Control Panel 7

Inside Filter Press Control Panel 8

Project Cost and Schedule • Project within budget • Contract duration 312 days 9

QUESTIONS? 10