Bunds (secondary containment areas) are designed to control spills, but in refineries they can also become blind spots: small leaks, rainwater mixed with hydrocarbons, drain valve failures, or seepage through joints may accumulate quietly until the event becomes operationally disruptive. When liquids remain undetected in a bund, the site faces a chain reaction of consequences: unplanned inspections, forced isolation of equipment, additional treatment or disposal steps, and a higher probability of escalation to environmental or safety incidents.

Early detection is not just about installing a sensor. It requires a repeatable architecture that works in harsh outdoor conditions, respects IT/OT boundaries, provides trustworthy alarms, and integrates with existing workflows. The Nasatech approach is a deployable NTX-based solution where field instrumentation feeds MQTT-native edge devices, connectivity is managed with Nasatech LINK, and data can be visualized, alerted on, and integrated via the optional Nasatech CORE Platform. The result is a practical pathway from “liquid detected” to “action executed” with traceability and controlled cybersecurity posture.

What this solution solves

Refinery bunds often contain a mix of operational complexity and uncertainty: multiple potential leak sources, intermittent exposure to rain and washdown, and varying liquid characteristics. A single missed event can trigger operational disruption—asset downtime, manual sampling, repeated patrols—and create uncertainty across maintenance and HSE teams. Conversely, overly sensitive detection can cause nuisance alarms that erode trust and result in alarm fatigue.

This solution targets early-stage conditions (first presence, abnormal level change, or hydrocarbon indication) and converts them into structured events suitable for operational response. It supports clear differentiation between “water present”, “potential hydrocarbon presence”, and “abnormal accumulation trend”, enabling teams to prioritize, dispatch, and document actions. The design is product-oriented: standard NTX field node + managed connectivity + optional platform and integrations, so deployments can scale from a few bunds to an entire site without redesigning the architecture each time.

How it works

The data flow is designed to align with modern plant architectures and to remain consistent whether the final consumer is a SCADA, a maintenance workflow, or an enterprise data layer:

  • Sensor / Instrumentation: field sensors detect liquid presence, level, and optionally hydrocarbon indication, installed at bund low points, sump pits, drain chambers, or perimeter hotspots. Typical instrumentation includes level switches, continuous level (e.g., hydrostatic), and hydrocarbon-in-water or conductivity-based detection depending on the containment design.
  • NTX Device (MQTT-native edge): a generic Nasatech NTX Field Node acquires the signals (digital/analog as required), applies edge conditioning (debounce, time validation, thresholds, rate-of-change, and basic plausibility checks), timestamps events, and publishes them natively via MQTT. Local buffering supports intermittent coverage without losing critical events.
  • Nasatech LINK (managed connectivity): provides low-power cellular connectivity as a default option for distributed outdoor assets. LINK manages secure transport, device connectivity health, and operational oversight so OT teams can focus on response rather than SIM and network administration.
  • Nasatech CORE Platform (optional): an open, scalable, robust platform that can host dashboards, alarm policies, escalation rules, and event histories. CORE can also act as a structured event hub that normalizes data models and forwards alarms/events to customer systems.
  • Customer integration: events and telemetry can be delivered to a customer MQTT broker, integrated through API/Webhooks, or forwarded to SCADA, CMMS, ERP, and/or a UNS (Unified Namespace) depending on the site’s target architecture.

From an architectural standpoint, the solution can be placed cleanly in a Purdue-aligned model. Field sensing and NTX edge nodes map naturally to Levels 0–1, while connectivity termination and event services can sit in an OT DMZ or controlled interface area. ISA-95 alignment is supported by separating real-time event handling (operations) from maintenance and enterprise workflows (work orders, compliance records, analytics). Where an UNS is in use, the solution publishes consistent MQTT topic structures and payloads that are suitable for enterprise-wide consumption without tightly coupling to a single application.

For potentially classified environments, the solution can be engineered to accommodate instrumentation and installation practices compatible with hazardous areas, subject to the project’s specific area classification and site standards. Selection of sensors, barriers, and enclosures is handled prudently to fit the refinery context without assuming certifications that are not explicitly specified.

Nasatech components

Nasatech NTX (Field Node) is the on-site device layer designed to be MQTT-native by design. For bund leak detection it operates as a compact, rugged edge gateway/data logger that interfaces with typical detection instrumentation (dry contacts, 4–20 mA, and other standard industrial I/O depending on the chosen sensor set). NTX is used to convert raw signals into operational events, apply local validation to reduce false alarms, and maintain continuity during intermittent connectivity.

Nasatech LINK is the managed connectivity service used to connect distributed containment points reliably, especially where cabling is costly or where bunds are spread across large units. LINK supports a consistent rollout model across multiple areas, with connectivity health monitoring as an operational input (e.g., “device online”, “last message”, “signal quality trend”) so teams can distinguish a real “all-clear” from a communications gap.

Nasatech CORE Platform (optional) adds an open, scalable layer for visualization, alerting, and integration orchestration. CORE is positioned as an enabler rather than a lock-in: it can forward data to the customer broker or UNS, integrate with ticketing/work order systems, and host role-based views for HSE, maintenance, and operations. CORE is suitable when the customer wants a consistent multi-site operational view, standardized alarm policies, or governance over event data.

Integration and scalability

This solution is designed to integrate without forcing a single control system strategy. Some refineries want alarms to appear in SCADA/HMI; others prefer to generate a CMMS notification or to feed an enterprise event stream. With MQTT-native NTX devices, integration can remain consistent while the consuming systems evolve over time.

Typical integration patterns include:

  • MQTT to customer broker / UNS: NTX publishes structured topics (site/area/bund/sensor) and payloads (state, quality, timestamp, diagnostics). This enables an UNS approach where multiple consumers (operations, maintenance, analytics) subscribe without point-to-point integrations.
  • API/Webhooks: event-driven push to incident workflows, paging/on-call tools, or middleware for ISA-95-aligned routing to maintenance and enterprise layers.
  • SCADA / OT applications: alarms can be mirrored into OT supervision tools through customer-standard gateways, while keeping the edge transport secure and independent.

Scalability is achieved by standardizing three elements: sensor classes (presence/level/hydrocarbon indication), NTX configurations (templates per bund type), and topic/data models (consistent naming and event taxonomy). This avoids re-engineering for each bund and supports incremental rollout across units, tank farms, and utilities areas.

Industrial cybersecurity is treated as an architectural requirement. The solution supports segmentation between IT and OT networks, with communications secured using TLS encryption and controlled access to device and platform interfaces. Where required, LINK and CORE can be positioned to terminate external connectivity in a controlled zone, enabling clear separation of field devices from enterprise systems and supporting auditability. Access control and credential management are implemented to reduce the attack surface and to ensure that only authorized systems publish/subscribe to operational topics.

Operational benefits

Earlier and more reliable detection of abnormal liquid presence in bunds supports proactive containment actions—inspection, isolation, drainage management, and verification—before the situation becomes disruptive. Edge validation on NTX helps reduce nuisance alarms by applying time persistence and plausibility checks rather than reacting to momentary transients.

Faster response with traceability: events are timestamped, categorized, and stored with diagnostic context (sensor state, device status, communication health). This enables teams to confirm what happened, when it started, and how it evolved, supporting both operational decision-making and post-event review.

Improved coordination across functions: by integrating with SCADA, CMMS, ERP, and/or an UNS, the same detected condition can trigger the right workflow—operator notification, maintenance request, HSE reporting—without manual re-entry. ISA-95-aligned routing helps keep real-time signals in operational channels while still enabling enterprise-level visibility.

Reduced operational uncertainty: connectivity health and device diagnostics provide confidence that “no alarm” actually means “normal”, not “offline”. This is especially important for remote bunds and tank farm perimeters where manual rounds are costly and inconsistent.

Application scenarios

1) Tank farm bund monitoring: continuous level trend plus discrete high-level thresholds in bund sumps, with event escalation when accumulation rate indicates active leakage rather than rainfall.

2) Bund drain valve supervision: detection of liquid presence near drain points combined with operational rules to flag abnormal persistence that suggests a valve left open or a blocked drainage path.

3) Process unit perimeter hotspots: distributed liquid presence sensors at low points around pipe racks and pump areas feeding NTX nodes, enabling rapid localization and dispatch.

4) Stormwater contamination early warning: integration of hydrocarbon indication sensors in runoff collection points to provide early alerts before downstream treatment systems are impacted.

Request a quote

Nasatech delivers this as a replicable NTX solution: standardized field node configurations, managed connectivity via Nasatech LINK, and an optional open Nasatech CORE Platform for alerting and integrations. To scope the right sensor set and rollout plan, we typically map bund types (sump-based, perimeter-based, drain-based), hazardous area constraints, preferred integration target (SCADA, CMMS, ERP, MQTT broker/UNS), and the site’s IT/OT segmentation requirements.

Request a quote to receive a recommended architecture (sensor classes + NTX configuration + LINK connectivity model), an integration approach aligned with Purdue/ISA-95, and an implementation outline suitable for pilot-to-scale deployment in refinery environments.