Environmental Manager

About the role

Why Castelion, Why Now Castelion is moving incredibly fast to develop and deliver advanced defense systems at a time when execution matters more than ever. We believe focus and technical excellence are decisive advantages - and we are building a team that can deliver real capability, not just concepts. This is a rare opportunity to join at an early stage, where your work will directly shape critical systems, influence major technical decisions, and have immediate, real-world impact.

Responsibilities

• Environmental Leadership Lead and continuously improve Castelion's environmental function in support of company growth. Establish environmental strategy, governance, and management systems aligned with business objectives. Serve as the company's primary environmental subject matter expert, providing technical guidance to leadership and Site EHS Managers. Develop environmental performance metrics and drive continuous improvement across all operating locations. Build and mentor a scalable environmental organization as the company grows.
• Permitting, Due Diligence & Regulatory Strategy Develop permitting strategies that support new facilities, manufacturing operations, testing, and future expansion. Lead environmental due diligence for new sites, acquisitions, leases, and development projects. Manage environmental permits and regulatory approvals throughout their lifecycle. Build productive relationships with environmental regulatory agencies and coordinate consultant support. Monitor emerging regulatory requirements and advise leadership on business impacts.
• Environmental Programs Develop, implement, and oversee company-wide environmental programs, including: Air quality compliance and permitting; Hazardous waste management, including characterization of complex and unique waste streams; Industrial stormwater (SWPPP), SPCC, wastewater, and EPCRA compliance; Environmental inspections, monitoring, and regulatory reporting; Environmental Management Systems (EMS) aligned with ISO 14001 principles.
• Operational Partnership Partner with Engineering, Manufacturing, Facilities, and Operations to integrate environmental requirements into projects and production. Support site selection, facility design, startup, commissioning, and operational readiness activities. Evaluate environmental impacts associated with new processes, equipment, chemicals, and production changes. Identify permitting and compliance requirements early to support efficient project execution. Provide practical environmental solutions that enable innovation and operational success.
• Environmental Risk & Continuous Improvement Lead environmental audits, assessments, and regulatory inspections. Investigate environmental incidents and drive corrective and preventive actions. Assess environmental risks and recommend mitigation strategies for existing and future operations. Promote lessons learned, pollution prevention, and environmental stewardship throughout the organization.

Requirements

• Bachelor's degree in Environmental Engineering, Environmental Science, Chemical Engineering, Civil Engineering, or a related technical discipline.
• 10+ years of progressive leadership and technical environmental experience supporting manufacturing, aerospace, defense, semiconductor, chemical processing, or other complex industrial operations.
• Demonstrated experience developing and implementing Environmental Management Systems (EMS), including programs aligned with ISO 14001 principles.
• Extensive knowledge of federal, state, and local environmental regulations governing industrial operations.
• Demonstrated experience obtaining, maintaining, and managing environmental permits and regulatory compliance programs.
• Experience supporting environmental due diligence for new facilities, property acquisitions, leases, or facility expansions.
• Experience managing hazardous waste programs, including characterization and management of complex or unique hazardous waste streams.
• Demonstrated ability to interpret environmental regulations and translate them into practical, risk-based operational solutions.
• Excellent written and verbal communication skills, with the ability to communicate complex environmental and regulatory concepts to technical and non-technical audiences.
• Highly organized with exceptional attention to detail and the ability to manage multiple priorities in a fast-paced environment.
• Strong project management, critical thinking, and problem-solving skills.
• Proven ability to build collaborative relationships, influence cross-functional teams, and drive environmental initiatives from concept through implementation.
• Ability to thrive in a fast-paced, high-growth environment while balancing strategic priorities with day-to-day operational support.
• Willingness to travel between company operating locations as needed.
• Ability to obtain and maintain a U.S. government–issued security clearance (U.S. citizenship required).

Skills

• Demonstrated experience developing and managing complex air quality permitting programs, including preparation, negotiation, modification, and ongoing compliance for major industrial operations.
• Demonstrated experience permitting complex manufacturing or industrial operations under one or more of the following regulatory agencies: SCAQMD, TCEQ, and/or NMED.
• Experience supporting greenfield facility development, manufacturing startups, or major facility expansions from planning through operational readiness.
• Experience supporting aerospace, defense, propulsion, energetics, or other high-consequence manufacturing environments.
• Experience with emissions inventories, air dispersion modeling, and long-term air permitting strategy.
• Professional certifications such as: Certified Hazardous Materials Manager (CHMM), Registered Environmental Manager (REM), Qualified Environmental Professional (QEP), Professional Engineer (PE).

Benefits

• All full-time employees are granted meaningful long-term equity, sharing in the company's significant growth trajectory.
• Four (4) weeks of paid time off.
• Ten (10) company-paid holidays.
• Comprehensive health benefits - including 100% employee-covered medical and strong dependent coverage, along with dental and vision plans.
• Paid parental leave to support growing families.
• $100 monthly fitness stipend to promote health and performance.
• Onsite EV charging for convenience.
• Catered meals, company-covered food during high-demand periods, and a fully stocked kitchen to stay fueled throughout the day.