Principal Civil Engineer

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 develop sound technical assessments in environments where complete information is rarely available. The ideal candidate combines creativity, engineering rigor, and exceptional analytical skills with a meticulous attention to detail. As a senior technical leader, you will collaborate with interdisciplinary teams of government and contractor professionals while serving as a trusted subject matter expert in support of complex intelligence and defense missions. Work is performed in a fast-paced, mission-focused environment within a government facility. Primary Responsibilities Reverse Engineering & Characterization Analyze and characterize complex industrial processes, equipment configurations, and facility designs to determine functional attributes, operational capabilities, and mission relevance. Subterranean & Hardened Facility Analysis Evaluate the structural design, geological overburden, and survivability of underground facilities (UGFs) and deeply buried hardened structures. 3D Modeling & Simulation Utilize advanced CAD and engineering simulation tools to develop accurate 3D models of facilities, underground structures, floor plans, utility systems, and supporting infrastructure. Vulnerability & Resilience Assessments Conduct detailed structural and functional analyses to identify systemic weaknesses, single points of failure, and assess the resilience of critical infrastructure against a range of threat vectors. Workflow & Infrastructure Analysis Evaluate facility support systems and operational workflows, including specialized HVAC systems, power distribution networks, utility infrastructure, and structural integrity considerations. Technical Reporting & Briefing Develop comprehensive engineering assessments, reports, and technical products in accordance with Intelligence Community standards. Present findings, technical analyses, and recommendations to senior government and Department of Defense stakeholders. Subject Matter Expertise & Technical Leadership Serve as a recognized subject matter expert within your technical domain, providing authoritative engineering guidance and supporting multidisciplinary teams addressing complex mission challenges. Required Basic Qualifications Security Clearance: Active TS/SCI clearance required. Must be a U.S. Citizen. Demonstrated expertise in engineering principles, theories, concepts, and their application across a broad range of highly complex programs and mission requirements. Master's degree with 15+ years of relevant experience, or a Doctorate with 13+ years of relevant experience. Relevant experience includes facility analysis, infrastructure vulnerability assessments, and structural engineering within commercial, Department of Defense, or Intelligence Community environments. Industrial & Facility Focus: Proven experience analyzing chemical, nuclear, or biological industrial processes and their associated facility footprints, including both above-ground facilities and subterranean environments. MEP Systems Knowledge: Strong multidisciplinary understanding of Mechanical, Electrical, and Plumbing (MEP) system design, integration, and operational functionality within complex industrial or military facilities, including specialized containment, filtration, and backup power systems. Preferred Qualifications Weapons Effects & Survivability: Experience or training in blast mitigation, weapons effects, or structural hardening principles. Geotechnical Engineering: Knowledge of rock mechanics, tunneling engineering, or geomechanics as applied to the analysis of deeply buried underground facilities (UGFs). BIM Expertise: Experience with Autodesk Revit or other Building Information Modeling (BIM) platforms for multidisciplinary coordination, MEP integration, and advanced facility visualization. Advanced Simulation: Experience utilizing BIM data to support engineering simulations, blast effects analysis, or vulnerability assessment workflows. Infrastructure Modeling: Experience with VENTSIM, ETAP, or similar infrastructure modeling and simulation software. All-Source Information Evaluation: Demonstrated experience researching, assessing, and synthesizing diverse intelligence and technical sources, including classified intelligence, open-source information, and grey literature such as foreign technical journals, patents, and equipment catalogs, to support facility and infrastructure characterization. Professional Engineer (PE) certification. Military or defense-related experience. If you're looking for comfort, keep scrolling. At Leidos, we outthink, outbuild, and outpace the status quo — because the mission demands it. We're not hiring followers. We're recruiting the ones who disrupt, provoke, and refuse to fail. Step 10 is ancient history. We're already at step 30 — and moving faster than anyone else dares. Original Posting: June 19, 2026 For U.S. Positions: While subject to change based on business needs, Leidos reasonably anticipates that this job requisition will remain open for at least 3 days with an anticipated close date of no earlier than 3 days after the original posting date as listed above. Pay Range: Pay Range $139,100.00 - $251,450.00 The Leidos pay range for this job level is a general guideline only and not a guarantee of compensation or salary. Additional factors considered in extending an offer include (but are not limited to) responsibilities of the job, education, experience, knowledge, skills, and abilities, as well as internal equity, alignment with market data, applicable bargaining agreement (if any), or other law. Leidos Leidos is an industry and technology leader serving government and commercial customers with smarter, more efficient digital and mission innovations. Headquartered in Reston, Virginia, with 47,000 global employees, Leidos reported annual revenues of approximately $17.2 billion for the fiscal year ended January 2, 2026. For more information, visit Pay and Benefits Pay and benefits are fundamental to any career decision. That's why we craft compensation packages that reflect the importance of the work we do for our customers. Employment benefits include competitive compensation, Health and Wellness programs, Income Protection, Paid Leave and Retirement. More details are available here. Securing Your Data Leidos will never ask you to provide payment-related information at any part of the employment application process. And Leidos will communicate with you only through emails that are sent from a Leidos.com email address. If you receive an email purporting to be from Leidos that asks for payment-related information or any other personal information, please report the email to View email address on click.appcast.io. Commitment and Diversity All qualified applicants will receive consideration for employment without regard to sex, race, ethnicity, age, national origin, citizenship, religion, physical or mental disability, medical condition, genetic information, pregnancy, family structure, marital status, ancestry, domestic partner status, sexual orientation, gender identity or expression, veteran or military status, or any other basis prohibited by law. Leidos will also consider for employment qualified applicants with criminal histories consistent with relevant laws.