Johnstown, CO

BACKGROUND

The Town of Johnstown (Town), Colorado operates a conventional

water treatment system utilizing dissolved air floatation (DAF) and

multi-media filters. The Town has started construction on a low

pressure membrane filter addition to replace the aging conventional

filters. To gain operational experience with controlled dosing, the

Town decided to implement the LowDose™ fully automated on-line

system incorporating the Anton Paar Litesizer™ zeta potential

analyzer.

Marmac Water was contracted to conduct jar testing to determine

the feasibility of incorporating our LowDose™ automated coagulant

dosing system. On-site jar testing, review of operational data and

observation of process performance determined that LowDose™ can

reduce coagulant demand while simultaneously improve

conventional and future membrane filter performance.

Control panel, analyzer enclosure and SCADA integration took one

day to install at the end of January 2024. The LowDose™ software incorporates an on-line zeta

potential analyzer as well as additional inputs pulled from the plant

SCADA system. Full-time input monitoring provides optimized

coagulant dosing which maintains desired particle charge of carryover

particles discharging from the dissolved air flotation system (DAF) to

the filter. Optimized dosing improves filter efficiency, reduces

coagulant, polymer, pH adjustment and chlorine demand. Optimized

dosing reduces operator attention and eliminates the need for jar

testing, especially during turbidity events.

RESULTS

IMPROVEMENTS

FEATURES

• Fully Automated

• Corrosion Monitoring

• Zeta Potential Driven

• Multiple Analyzer Inputs

• Auto TOC and DBP Compliance

• Temperature Compensation

• Auto & Enhanced Coagulation

• Charged Value Polymer Dosing

• SCADA Integration

Case Histories