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Wastewater

Markets

Municipal Utilities

OC San accelerates critical digester rehabilitation to address urgent safety concerns

During investigations for Orange County Sanitation District's broader P2-137 Digester Rehabilitation Program, extensive corrosion was identified in the post-tension rings at the top of the tank walls of Digesters P and R. Because of the resulting safety concerns, OC San advanced P2-137A as an accelerated rehabilitation project. CDM Smith supported condition assessments, engineering evaluations, and expedited design services to restore structural integrity and help ensure safe, reliable operation of these critical solids-processing facilities.

Performing targeted condition assessments 

The team conducted detailed structural investigations and engineering evaluations to determine the extent of deterioration affecting Digesters P and R. These assessments provided the technical basis for rehabilitation strategies and accelerated project delivery.

Using advanced inspection technologies 

Drone inspections supported exterior facility evaluations while reducing exposure to hazardous conditions. Thermal imaging helped identify areas requiring further investigation, improving the safety and efficiency of field assessments.

Evaluating corrosion without shutdowns 

Half-cell potential testing identified severe corrosion affecting the post-tensioning system. A specialized venting protocol enabled safe testing and investigation activities while allowing digesters to remain in operation.

Delivering accelerated design solutions 

To address urgent safety concerns, CDM Smith developed an accelerated design package focused on Digesters P and R. The approach allowed critical rehabilitation work to advance rapidly into construction while broader digester rehabilitation planning continued.

To evaluate Digesters P and R while maintaining operations, CDM Smith combined advanced inspection technologies with specialized testing methods. Drone inspections and thermal imaging improved safety and helped identify areas requiring further investigation. Half-cell potential testing confirmed severe corrosion in the post-tension ring system, while a customized venting protocol allowed safe testing and selective demolition without taking the digesters out of service. These findings informed an accelerated rehabilitation design developed to address urgent safety concerns and support construction of critical repairs.

Practices

Wastewater

Markets

Municipal Utilities

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Hala Titus

North America Unit President

Hala leads regional sales and delivery teams while advancing firmwide growth strategies. She is committed to delivering innovative, cost-effective solutions and ensuring CDM Smith remains every client’s trusted advisor and partner.

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