Information Security Analyst jobs in United Kingdom

As an Operational Technology (OT) Network Engineer, you will be responsible for managing, supporting, and securing Thames Water’s OT network infrastructure. These network systems are vital for enabling remote control, monitoring, and data acquisition across Water and Wastewater and Electronic Security System Assets, helping to deliver essential services to our customers, communities, and the environment.

This role involves ensuring that OT network assets and systems remain highly available, secure, and aligned with business and industry best practices. You will contribute to both day-to-day operations and long-term strategic improvements, including digital transformation initiatives across the OT estate.

What you’ll be doing as an Operational Technology (OT) Network Engineer

• Act as a Subject Matter Expert (SME) on network routing, switching, and associated OT network infrastructure.
• Support the operational reliability of OT network systems to ensure 99.98% availability of critical assets.
• Lead and support the delivery of network changes in line with change management and risk assessment procedures to minimise operational impact.
• Maintain OT network standards, configurations, and firmware in accordance with defined policies and procedures.
• Provide technical support across the design, build, and delivery of both high-level and low-level network solutions.
• Deliver updates and upgrades to routers, switches, firewalls, and other network components at agreed intervals.
• Manage and monitor OT network system security, including compliance audits, licence reviews, and obsolescence tracking.
• Configure and support a wide range of technologies including Fortinet, CheckPoint, Cisco security appliances, Hirschmann HiVision, VPNs, Radius, Active Directory, SolarWinds, and Pulse Secure.
• Manage routing and switching protocols including OSPF, RIP, BGP, MPLS, NAT, VLAN, STP, and policy-based routing.
• Apply principles of cloud IaaS networking and assist in secure connectivity between cloud and on-prem systems.
• Identify, assess, and implement security improvements in line with cyber and operational risk requirements.
• Respond to incidents and provide 24/7 out-of-hours support for the OT network, as part of a shared on-call rota.
• Collaborate with internal stakeholders across OT and operational teams to deliver network improvements and project support.
• Support internal and capital delivery projects by providing network design, implementation, and technical oversight.
• Engage in continuous improvement initiatives through lessons learned, internal feedback, and proactive issue resolution.
• Maintain accurate records of preventative and reactive maintenance, and complete relevant documentation as required.
• Identify skill gaps and contribute to personal development planning (PDP) to ensure continuous growth and learning.

Base location – Hybrid – Sewage Treatment Works, Reading

Working pattern – 36 hours Monday to Friday

• Higher education qualification (HNC or equivalent experience) in an engineering or IT discipline.
• Security clearance to SC level or the ability to obtain it.
• Proven experience in maintaining and supporting enterprise network infrastructure within a large organisation.
• Industry-recognised networking certifications (e.g. CCNP, CCNA minimum, CheckPoint CCSE/CCSA).
• Strong understanding of IP networking, including LAN, WAN, and routing protocols (OSPF, BGP, RIP, MPLS).
• Experience managing network security technologies (e.g., firewalls, VPNs, anomaly detection).
• Proficiency in network monitoring and management tools such as SolarWinds, Tufin, and Hirschmann HiVision.
• Confident decision-making skills with the ability to balance operational, technical, and customer priorities.
• Excellent communication and interpersonal skills, capable of working with technical and non-technical stakeholders.
• Valid UK driving licence and ability to participate in an on-call support rota.
• Strong documentation, report writing, and root cause analysis skills.
• Proficient in MS Office, including Visio for network diagramming.
• Understanding of IT and OT service delivery approaches (ITIL, Agile, Lean).

• Experience working in the utilities or water industry.
• Familiarity with SCADA and telemetry systems or willingness to learn.
• Knowledge of mobile communications, remote access technologies, and cloud networking principles.
• Understanding of virtualisation platforms (e.g., VMware, Hyper-V) and basic scripting (e.g., PowerShell, cmd).
• Experience managing conflicting priorities and stakeholder demands in a high-pressure environment.
• Exposure to OT cyber-physical systems and IT/OT convergence projects.

• Competitive salary up to £65,000 per annum, depending on experience.
• Annual Leave - 26 days holiday per year, increasing to 30 with the length of service. (plus bank holidays).
• Generous Pension Scheme through AON.
• Performance-related pay plan directly linked to both company and individual performance measures and targets.
• Access to lots of benefits to help you take care of you and your family’s health and wellbeing, and your finances – from annual health MOTs and access to physiotherapy and counselling to Cycle to Work schemes, shopping vouchers and life assurance.

We’re the UK’s largest water and wastewater company, with more than 16 million customers relying on us every day to supply water for their taps and toilets. We want to build a better future for all, helping our customers, communities, people, and the planet to thrive. It’s a big job and we’ve got a long way to go, so we need help from passionate and skilled people, committed to making a difference and getting us to where we want to be in the years and decades to come.

Learn more about our purpose and values

Thames Water is a unique, rewarding, and diverse place to work, where every day you can make a difference, yet no day is the same. As part of our family, you’ll enjoy meaningful career opportunities, flexible working arrangements and excellent benefits.

If you’re looking for a sustainable and successful career where you can make a daily difference to millions of people’s lives while helping to protect the world of water for future generations, we’ll be here to support you every step of the way. Together, we can build a better future for our customers, our region, and our planet.

Real purpose, real support, real opportunities. Come and join the Thames Water family. Why choose us? Learn more.

We’re committed to being a great, diverse, and inclusive place to work. We welcome applications from everyone and want to ensure you feel supported throughout the recruitment process. If you need any adjustments, whether that’s extra time, accessible formats, or anything else just let us know, we’re here to help and support.

Disclaimer: due to the high volume of applications we receive, we may close the advert earlier than the advertised date, so we encourage you to apply as soon as possible to avoid disappointment.