**Description**

**Principal Civil Engineer (TS/SCI Required)**

**Location:** Reston, VA

Leidos is seeking an accomplished **Principal** **Civil Engineer** to support high-priority national security missions in Reston, Virginia. This role focuses on the assessment, reverse engineering, and characterization of complex above-ground and subterranean facilities located in denied-access environments.

The successful candidate will leverage extensive engineering expertise to reconstruct facility layouts, operational workflows, and supporting infrastructure associated with chemical, biological, radiological, and nuclear (CBRN) industrial processes. Through detailed analysis of facility design, operations, and infrastructure, you will identify vulnerabilities, assess potential threat vectors, and provide critical engineering insights that support mission planning and decision-making.

This position requires a highly experienced engineer who can de...