PIPELINE CONSTRUCTION Modern water management is undergoing a fundamental transformation; it is no longer just about safe transport and supply, but also the proactive protection of drinking water resources from external influences. Against the backdrop of climate change, new evidence of pollutants, and stricter regulatory requirements, infrastructure is evolving from a passive carrier into an integral component of risk management.
In addition to traditional risks, new influencing factors are increasingly gaining importance. These include climate-related changes, such as rising soil temperatures and longer residence times in the network, which can affect the microbiological stability of drinking water. At the same time, aspects of supply security and the protection of critical infrastructures (KRITIS) are coming into sharper focus, for example, regarding external impacts from construction activities or targeted manipulations. Against this background, the need for expanded condition information that goes beyond traditional point-based measurement and testing procedures is increasing.
European and national frameworks
With the recast of the EU Drinking Water Directive (Directive 2020/2184) as well as its implementation in the Drinking Water Ordinance (TrinkwV 2023) and the Drinking Water Catchment Area Ordinance (TrinkwEGV 2023), the regulatory focus is shifting: it is not just about compliance with individual parameters in random samples, but about systematic risk management along the entire chain from extraction and transport to consumption.
Requirements for risk assessment are becoming increasingly complex. In addition to considering individual substance parameters, a holistic assessment of the entire supply chain is moving to the forefront. This involves not only taking known hazards into account but also potential future risks, such as new sources of pollutants or changed land use in the catchment area. The goal is to identify risks early and limit them through suitable preventive measures.
Relevant substance parameters and consequences for infrastructure
The ordinances introduce new, sometimes very low limit values (e.g., total PFAS 0.1 μg/l). These limits apply to the chemical composition of the drinking water. For the infrastructure, these specifications specifically mean: increased requirements for material resistance, tightness over the service life, and measurement and detection methods. Organic, mobilizable substances (BTEX, CHCs) and persistent substance classes (PFAS) are particularly relevant. Systematic protection concepts are therefore required in contaminated or risk-prone routes.
Drinking water protection zones
Zoning (I–III) structures the protection areas for drinking water resources.
- Zone I (Catchment area): Subject to the highest restrictions, as immediate danger to the extraction facility must be prevented here.
- Zone II (Narrower protection zone): Also places particularly high demands on the infrastructure. Recognized technical rules (e.g., DWA-A 142) require suitable measures for high-risk routes, such as permanent leak monitoring and protection concepts to prevent infiltration.
- Zone III (Further protection zone): Here, measures primarily serve to protect against large-scale or poorly degradable chemical contamination.
For Design Engineers and operators, this means: where routes pass through Zone II, leak-monitored and testable solutions must be provided to prevent the release of pollutants into the soil (Fig. 2).
Consequence for Design Engineers and operators
The new requirements shift the focus from one-time acceptance testing to ongoing integrity and risk assessment. Choice of material, connection technology, testing concepts, and operational processes must be considered during the planning phase and anchored in operations.
Traditional sampling procedures continue to provide the basis for compliance with quality requirements, but they only offer a limited representation of temporal and spatial changes in the network. Supplementary condition information can help to identify operational developments early and evaluate them in a targeted manner.
Climate-related changes and increased requirements for the resilience of critical infrastructures mean that, in addition to traditional quality parameters, operational influencing factors such as temperature trends or external impacts on the infrastructure are increasingly included in the assessment.
Material science fundamentals
The selection of suitable pipe materials is crucial for the safety, hygiene, and longevity of drinking water pipes. Modern plastic pipe systems must meet technical, ecological, and economic requirements in equal measure.
Material selection and basic requirements
Stress-crack-resistant PE types such as PE100-RC are now the standard for pressure pipelines in supply and disposal. Relevant material properties are:
- Hygienic and chemical advantages: Chemical inertness towards drinking water and freedom from corrosion (KTW-relevant).
- Longevity and flexibility: High stress-crack resistance, longevity (50 years and more), and flexibility, which allows for high adaptability to soil movements.
- Ease of installation: Low weight and the possibility of delivery in long lengths reduce connection points and simplify installation.
Permeation and barrier requirements
Permeation describes the penetration of volatile or soluble substances through a polymer matrix. For high-risk locations contaminated by, for example, CHCs or BTEX, the pure diffusion resistance of standard PE pipes is often insufficient. Instead, multi-layer systems with a metallic barrier layer or other diffusion-inhibiting layers are used (Fig. 3). Such barrier systems prevent substance transport and are described as suitable measures in guidelines such as KIWA BRL 17101 for ensuring drinking water quality.
Mechanical integrity, connections, and processing quality
The mechanical tightness of a pipeline is the result of the pipe material, fittings, and connection technology. Welded joints according to DVS guidelines (e.g., DVS 2207) are central, as errors in connection technology are one of the most common causes of leaks in practice. Processing quality is therefore a primary criterion for permanent network security.
Life cycle assessment and contribution to climate friendliness
The protection of drinking water is closely linked to the protection of the environment. The life cycle assessment (LCA) of plastic pipes must be evaluated in the context of functional reliability and the entire service life:
- Climate friendliness in the overall assessment: In life cycle analysis, taking into account transport, longevity, and low maintenance intensity, PE pipes are considered more climate-friendly than many alternative materials.
- Resource conservation through tightness: The permanent tightness of plastic pipes prevents massive water losses and reduces the energy required for water pumping and treatment.
- Economic advantages: Due to their low weight, they reduce transport emissions. Furthermore, they can be delivered in long lengths, which shortens construction times and minimizes connection points.
Technological solution approaches
Modern plastic pipe systems offer functional intermediate layers to meet the stricter regulatory requirements (Fig. 4).
Passive protection through integrated barrier layer
Multi-layer pipes such as the Barrier Pipe SLA system combine the mechanical advantages of PE100-RC with a metallic barrier against organic pollutants. The system features an integrated, certified aluminum barrier layer that prevents permeation over the entire service life of the pipeline.
The selection of these systems is based on a hazard analysis (soil and groundwater samples) by the operator or the engineering firm. The testing strategy for long-term effects must take into account the specifications of an internationally recognized testing guideline such as KIWA BRL 17101, which serves to ensure drinking water quality and is used as a basis for verification.
Active protection through monitoring
Monitored pipe systems enable the continuous detection of leaks and allow for a constant condition assessment of the pipeline.
Technically proven concepts utilize electrically conductive intermediate layers or integrated conductor strips. By applying a very low voltage to the conductor and measuring the insulation resistance against the ground, the condition of the pipeline can be monitored. Such systems provide alarm messages and offer the possibility of precisely locating potential damage.
Examples of such monitoring systems include egeSmart:Integrity DCS and egeSmart:LeakControl 3L from egeplast. In the egeSmart:LeakControl 3L, the electrical conductor simultaneously serves as a permeation barrier layer, meaning the system meets the highest safety requirements. Such systems contribute not only to operational safety but also to hazard prevention: they detect leaks early and enable a rapid response.
Beyond traditional leak monitoring, modern systems are increasingly expanding their range of functions. This includes, in particular, the recording of temperature profiles along the pipeline, the detection of external impacts, and the provision of continuous condition data for network operation. These developments are linked to increasing requirements for the resilience of critical infrastructures and the need to detect even non-immediately recognizable changes at an early stage (Fig. 5).
Advanced condition monitoring and digitalization
Against the backdrop of increasing requirements for transparency, verifiability, and risk-based network operation, the continuous, linear acquisition of condition data is becoming increasingly important.
A technological basis for this is provided by fiber-optic measurement systems (Distributed Temperature Sensing, DTS). By coupling light signals into an optical fiber guided beneath the protective jacket and evaluating the backscatter, the temperature can be determined continuously at every point of the fiber.
The resulting possibilities go beyond traditional monitoring approaches:
- Continuous temperature profiles to identify operational anomalies and potential microbiological risks
- Detection of external impacts along the route
- Continuous condition data as a basis for data-driven asset management
- Optional use as data infrastructure
- Direct and precise localization of damage events
An example of this technology is the innovative egeSmart:Data system from egeplast, which enables continuous monitoring of pipeline routes over long distances and can be integrated into existing control and evaluation systems
.
In contrast to point-based measurement methods, such systems provide comprehensive condition information that enables a new quality of network assessment and thus supports the transition to preventive, data-driven network operation.
Regulatory alignment
The integration of specialized plastic pipe systems enables network operators and Design Engineers to comprehensively fulfill the risk-based approach of the Drinking Water Ordinance 2023 and the Drinking Water Catchment Area Ordinance (Table 1).
Conclusion and outlook
The increased requirements for the protection of drinking water require an integrative approach: material selection, construction measures, and continuous condition monitoring must be viewed as an interconnected system. Plastic pipe systems are evolving from a pure transport medium into active components of a risk-based infrastructure concept (Fig. 6 + 7).
Key points for practice
- Risk-based selection: The decision for pipes with a barrier layer or monitoring systems must be based on a sound soil and hazard analysis.
- Combined protection concept: Passive barriers are
used where diffusion is relevant. Active
monitoring is used where leaks are operationally or regulatorily high-risk (e.g., WSZ II). - Operational processes: Monitoring must be integrated into alarm logic, escalation plans, and asset management to derive immediate action consequences from data.
Against the backdrop of climate change, increasing requirements for the resilience of critical infrastructures, and growing regulatory specifications, the continuous acquisition of condition data along the pipeline is becoming increasingly important. In particular, fiber-optic measurement systems enable a previously unavailable level of transparency in network operation.
Thus, in the future, infrastructure will evolve into a data-based, adaptive system that not only reacts to disturbances but detects and limits their occurrence at an early stage. Plastic pipes therefore not only contribute to safe transport but form the basis for a monitored, resilient, and future-proof drinking water supply.
Literature
[1] Federal Ministry of Health (BMG). (2023). Ordinance on the Quality of Water for Human Consumption (Drinking Water Ordinance – TrinkwV 2023). Federal Law Gazette 2023 I No. 159. Available at: https://www.gesetze-im-internet.de/trinkwv_2023/.
[2] Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection (BMUV). (2024). Ordinance on Catchment Areas of Extraction Points for Drinking Water Production (Drinking Water Catchment Area Ordinance – TrinkwEGV). Federal Law Gazette 2024 No. 346.
[3] German Association for Water Management, Wastewater and Waste (DWA). (2024). Worksheet DWA-A 142: Wastewater lines and sewers in water catchment areas. DWA, Hennef. Available at: https://de.dwa.de/de/regelwerk.html.
