The Facility

In December 2010, the Colusa Generating Station, a 660-megawatt power plant located near the town of Maxwell in Colusa County began commercial operation. This facility incorporates the latest technology and environmental design to reduce emissions and dramatically lower water usage compared to conventional natural gas power plants. Cleaner burning turbines will allow the facility to use less fuel and emit 35 percent less carbon dioxide than older plants. The Colusa Generating Station will serve PG&E’s comprehensive energy strategy to meet California’s future energy needs with cost-effective and clean power supplies.

Project Overview

The Colusa Generating System will be dry cooled, preserving local water typically needed for power generation. The facility will capture steam generated during operation which will be condensed back into water and recycled through the plant to produce additional power. Further, water will be recycled through a Zero Liquid Discharge system that cleans potential wastewater for reuse throughout the plant. Aquatech was awarded a contract from Gemma Power Systems for this equipment.

Scope of Service

The equipment that Aquatech provided included: Potable Ultrafiltration 300 GPM (68 m³/hr); Wastewater Ultrafiltration 500 GPM (114 m³/hr); Reverse Osmosis 60 GPM (14 m³/hr); Wastewater Reverse Osmosis 30 GPM (7 m³/hr); Forced Circulation Crystallizer; 10 GPM (2.2 m³/hr); which led to Zero Liquid Discharge.

Design Water Analysis

Water Quality ParameterColusa Average ConcentrationWater Quality ParameterColusa Average Concentration
Turbidity3.8 NTUBeryllium2.3 ug/L
Color10Total Alkalinity78 mg/L
pH8.3Bicarbonate78 mg/L
Total Suspended Solids35 mg/LSulfate7.4 mg/L
Total Dissolved Solids94 mg/LChloride5.4 mg/L
Hardness as CaCO262 mg/LNitrate1.2 mg/L
Calcium20 mg/LFluoride<0.1 mg/L
Magnesium2.9 mg/LArsenic<0.005 mg/L
Sodium8.0 mg/LIron<0.1 mg/L
Potassium1.2 mg/LBoron<0.1 mg/L
Barium28 ug/LSilica8.8 mg/L
 Notes: ug/L = micrograms per liter,mg/L = milligrams per literNTU = Nepholometric turbidity units

Process Flow Diagram

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