Fairfax County WWTP Clarifiers

CTLGroup conducted an evaluation of the Tertiary Clarifier Facilities at Noman M. Cole Jr. Pollution Control Plant in Lorton, Fairfax County, Virginia. The tertiary clarifier facilities are approximately 40 years old and are constructed of reinforced concrete.

CTLGroup performed an evaluation of the tertiary clarifier facilities, including four clarifiers and 1,200 lineal feet of underground concrete galleries. Our work scope included review of available project documents and field investigation consisting of visual survey, sounding survey, photographic documentation, and generation of a repair work item list. The results of our document review and field investigation were compiled into a report that presented specific repair recommendations for each repair work item list observed during the field investigation. Repair recommendations included repair details and notes, specifications, and recommended repair materials.


Civil Infrastructure

Energy & Resources

Consulting Services

Structural Engineering + Evaluation

Repair, Restoration, Retrofit

Structural Condition Assessment

Laboratory Services

Concrete + Cement-Based Materials

The Fairfax County sanitary sewer treatment is accomplished through multiple jurisdictional agreements which allows the sewer flow to convey to one of six regional treatment facilities.


Year of Completion


Hours Worked


Analyses Conducted Per Year By Plant

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Project Detail Form

Project Detail Form