Join a fast-growing, forward-thinking Geo-Environmental team delivering technically complex solutions across energy, water, defence, nuclear and property sectors. Purpose & Scope of the Role As a Principal Geo-Environmental Engineer, you will play a key role within a multidisciplinary team of specialists delivering high-quality consultancy services supported by in-house ground investigation capabilities. Operating across a diverse project portfolio, you'll contribute to technically robust, client-focused solutions spanning land quality, remediation, groundwater and geotechnical disciplines. You'll take ownership of projects from planning through to delivery-combining technical expertise, stakeholder engagement and effective project management. Working collaboratively across regional offices and wider environmental and engineering teams, you'll help drive continued growth and strengthen client relationships. Your Impact in this Position You'll lead and influence the successful delivery of geo-environmental projects-providing technical direction, mentoring colleagues and ensuring excellence in reporting and interpretation. Your expertise will directly support informed decision-making for clients, while your commercial awareness and communication skills will help expand our project pipeline and reinforce our reputation in the market. Core Capabilities Technical Excellence Apply strong geo-environmental knowledge, with the ability to produce and review Phase 1 and Phase 2 reports, risk assessments and interpretative outputs to a high professional standard. Project & Site Management Plan, manage and supervise ground investigations, including groundwater and gas monitoring, ensuring safe, efficient and compliant site operations. Client & Stakeholder Engagement Build trusted relationships with clients and stakeholders, confidently communicating technical information and delivering practical, value-driven solutions. Collaboration & Leadership Work seamlessly across multidisciplinary teams, contributing to a supportive culture while guiding and mentoring less experienced colleagues. Commercial Awareness & Growth Support business development activities and contribute to strategic growth through proactive client engagement and high-quality project delivery. Skills, Experience & Qualifications Degree in geology, engineering geology, hydrogeology or environmental science (postgraduate desirable). Proven industry experience with contaminated land assessment and UK regulatory frameworks. Working towards Chartership (e.g. CIWEM, IEMA, Geological Society). Strong reporting, data interpretation and IT skills essential. Site experience and relevant certifications (e.g. CSCS, SMSTS) beneficial. Working Environment This role offers a flexible, hybrid working model. Expect a mix of office, site work and remote working, depending on project needs. Approximately 50% site-based work, primarily within Northern Ireland, with occasional travel further afield (expenses covered). Flexible hours, part-time and job share options are supported to promote a healthy work-life balance. About Tetra Tech Tetra Tech is a leading provider of consulting and engineering services working across the full project lifecycle worldwide. We have a wide range of expertise across our teams, providing a global support network with a personalised approach to client relationships to better understand where we can add value. We provide a collaborative environment that supports individual performance, innovation, and creativity. We support public and private sector clients on local, national, and international projects to deliver sustainable and resilient solutions. Our operations in the UK, Ireland, and the Netherlands include more than 6,000 employees who are Leading with Science® to solve our clients' most complex problems. In alignment with the Equality Act 2010, we will make reasonable adjustments to support candidates and employees requiring additional arrangements. This could include adaptations to work schedules, training approaches, or the physical workspace. Please inform us if you need any accommodations during the recruitment process or in your day-to-day role