Water & Wastewater › Wastewater Systems
Wastewater Treatment
Plant processes and the control strategies that run them.
Written guides in this section
Full references, procedures, and diagnostic guides published under Wastewater Treatment.
Headworks Control
The first stop for raw wastewater: influent flow measurement, mechanical screens and their differential level control, grit removal, influent pumping where the plant needs it, the odor and hazardous atmosphere considerations that shape the electrical design, and what SCADA needs from the headworks.
10 min readUpdated Sep 5, 2026
Aeration Control
Controlling the largest energy user at a wastewater plant: the DO cascade to airflow, blower staging and turndown, most-open-valve pressure control across basins, ammonia-based aeration control, the instruments each strategy depends on, and the interlocks that keep blowers out of surge.
11 min readUpdated Sep 5, 2026
Biological Treatment
The biological process from the controls side: activated sludge and its common forms, conventional, extended aeration, oxidation ditch, sequencing batch reactor, and membrane bioreactor, and the alarms that give an operator time.
9 min readUpdated Sep 5, 2026
Clarifier Control
Primary and secondary clarifiers from the control room: the mechanism drive and its torque protection, sludge blanket measurement and sludge withdrawal control, scum removal, the weir and the effluent turbidity, and the sludge blanket as the early warning for a secondary process losing its footing.
9 min readUpdated Sep 5, 2026
RAS and WAS Control
Return and waste activated sludge: what each flow does for the process, RAS control by influent flow ratio or by blanket level, WAS control to a target sludge age or a target mixed liquor concentration, the flow and solids measurements each needs, and the pump and valve arrangements that make the setpoints achievable.
10 min readUpdated Sep 5, 2026
Chemical Systems in Wastewater Treatment
The chemical feeds of a wastewater plant and their controls: coagulants for phosphorus, polymer for thickening and dewatering, hypochlorite and sulfite for disinfection and dechlorination, and the alarms that keep the plant in its permit.
9 min readUpdated Sep 5, 2026
Topics in this area
Headworks
Headworks — practical reference notes for controls engineers, integrators, and technicians working with wastewater treatment.
Aeration Control
Aeration Control — practical reference notes for controls engineers, integrators, and technicians working with wastewater treatment.
Biological Treatment
Biological Treatment — practical reference notes for controls engineers, integrators, and technicians working with wastewater treatment.
Clarifiers
Clarifiers — practical reference notes for controls engineers, integrators, and technicians working with wastewater treatment.
RAS/WAS
RAS/WAS — practical reference notes for controls engineers, integrators, and technicians working with wastewater treatment.
Chemical Systems
Chemical Systems — practical reference notes for controls engineers, integrators, and technicians working with wastewater treatment.
Effluent Disinfection
Effluent Disinfection — practical reference notes for controls engineers, integrators, and technicians working with wastewater treatment.
Effluent
Effluent — practical reference notes for controls engineers, integrators, and technicians working with wastewater treatment.
Residuals
Residuals — practical reference notes for controls engineers, integrators, and technicians working with wastewater treatment.
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