3L Leak Control system in water protection areas

Projekt Wasserschutzgebiet Schweiz

The provision of a new sewer to be connected to the downstream wastewater treatment plant in Liedertswil, Switzerland, involved passing through two water protection areas. Permanent leakage monitoring required for this purpose is ensured by the egeplast 3L safety pipe system. The direct connection to the central treatment plant featuring the fully monitored pipe system delivers a 40 % cost benefit for the operator.

Project water protection area Switzerland

Beforehand, the Department for industrial Companies had conducted a variation study to assess whether the local sewage treatment plant in Liedertswil in the Swiss district of Basel-Landschaft was to be rehabilitated or whether a new one was to be built, or whether a connection channel through a water protection area to the closest central sewage treatment plant was to be installed. After all, the plant, which took up its operations in 1968 – one of 22 decentralised sewage treatment plants of the Department for industrial Companies – was in significant need of maintenance and expansion.

The study revealed that due to the confined space conditions on site, erecting a new plant at the same location is not possible considering the requirement to enhance plant safety, which in turn involves additional space requirements. Due to the groundwater protection zone type 2 a new plant would mean encreased requirements in terms of the design of the structure and the surveillance technology.

A comparison of the annual costs for the different variants revealed a cost advantage of around 40% for the connection channel through the water protection area to the closest sewage treatment plant. In addition, another benefit of centralised sewage treatment is increased operational safety and cleaning performance. Moreover, the direct connection will provide the required capacities for community development.

Against this background, the principal decided in favour of building a new sewer creating a connection to the regional sewage water treatment plant in Niederdorf. The route leads through two water protection areas and thus requires monitoring. The solution for the approx. 1.7 km long passage through the water protection zones is the 3L safety pipe system by egeplast, for which OD 315 was selected.

The fully monitored pipe system ensures 100-percent leakage monitoring for soil and water protection. Early detection of leakages thanks to continuous monitoring of the relevant values enables the operator to take action before a potential damage occurs and thus to prevent disasters. This early warning system facilitates safe transportation of substances hazardous to waters through ground water protection zones and has been described and approved by the applicable professional rules (e. g. ATV-DVWK-A-142).

3L Leak Control in the water protection area

Remote maintenance and permanent control of the monitored pipe system

The 3L safety pipe system is a pipe system featuring permanent or intermittent monitoring designed to report and locate damages – even if there is no mains connection. This monitored pipe system can also be accessed and controlled online via any internet access in accordance with the state of the art and thus enables the operator to take action quickly.

A monitoring unit connected to the pipe will trigger an alarm even in the event of minor damages to the pipe system. The reports are sent either directly to the control centre or to a smartphone or can be accessed online.

Project data

Project description: Construction of a new gravity sewer as a connection channel of a decentralized sewage water treatment plant to the closest sewage plant
Challenges: The planned pipe route leads through two water protection areas.
Solution: A pipe system which can be fully monitored meets the increased requirements applicable for water protection areas.
Installation: Open-trench installation
Pipe system: 3L Leak Control
OD 315 mm SDR 17
1,700 m
Parties involved in the project: Planning: Jauslin Stebler AG, Muttenz, Schweiz

Manholes were used in the water protection area


Daniel Pfarrer
Jauslin Stebler AG
Tel: +41 61 467 6767
Michael Fischer
Amt für Industrielle Betriebe
Tel: +41 61 315 10 41
Dirk den Ouden
egeplast international GmbH
Tel: +49 2575 9710 271

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