Rehabilitation design for the sewer network at the Volkswagen plant in Wolfsburg

ITAS Salzgitter GmbH – engineers for civil engineering, wastewater & rehabilitation – was commissioned by the Facility Management department of the Volkswagen plant in Wolfsburg to develop a sewer rehabilitation plan. The sewer network of the factory premises is comparable to that of a small town, but more demanding because of numerous, branched-off structures obstructing access. In addition, the client has high standards in regards to data compatibility and transparency. Using BaSYS PISA, the BARTHAUER software solution for rehabilitation planning, ITAS can provide efficient task-driven solutions and thereby reduce processing times for sewer rehabilitation by about 20 per cent.

ITAS Salzgitter GmbH for Volkswagen AG, Wolfsburg plant
• 350 km of rainwater and wastewater sewers
• 120 km of main and collecting channels

• Data capture and import
• Condition assessment
• Rehabilitation design and cost estimating


Project start
• February 2011

ITAS Salzgitter GmbH
ITAS Salzgitter GmbH is an engineering firm specialising in the rehabilitation design, consulting and project management of technical infrastructure. Building on many years of experience and specialisation, the ITAS engineers live the claim to always find the most cost-effective and technically most rational solution for their clients. One of their principles therefore is: “The early recording of the nature and extent of the damage is often already halfway to its elimination.” The engineers use the powerful tools of Barthauer Software GmbH to do their advance planning. Their objective is efficient and cost-effective sewer rehabilitation that benefits the client. In collaboration with the Facility Management department, ITAS Salzgitter assisted in taking stock of the sewer network by means of a TV inspection and created a damage assessment of the factory premises from the results. Proposals for the rehabilitation and its cost are subsequently submitted.

Sewer lines run under the production lines
At the Wolfsburg site, Volkswagen AG operates a separation process through an extensive sewer network. The length of the rainwater and wastewater sewers is comparable to the network of a small town, amounting to a total of about 350 km. A sewer network of about 230 km accounts for small-sized connecting channels leading from the individual wastewater and rain water collection points to the collecting channels. The network of main and collecting channels is about 120 km long. 70 per cent of the sewage pipes are located below the production halls and are therefore not easily accessible. This already complicated data collection and the classification of the pipelines, and must be taken into account when planning the rehabilitation measures. In an industrial plant of this size and structure, sewer rehabilitation is of decisive importance.

Overview with uniform plans
In the first step, it was necessary to obtain an overview of the condition of the sprawling sewer network. From the available as-built drawings and the visual inspections, uniform plans should be drawn up. The emphasis is on the simplification and standardisation of site plans and databases with the aim of accomplishing the flow of data between client and service provider across divisions. Therefore, the staff of the Facility Management department wanted to have access to digital plans and rehabilitation design in the ISYBAU exchange format in accordance with the sewage directives. The proven ISYBAU concept enables the uniform and consistent exchange of all wastewater data. Originally designed for properties belonging to the Federal Government, the ISYBAU standard is now widely used by industry professionals. Barthauer Software GmbH was involved in the development of the ISYBAU concept from the start and so could provide a network information system that perfectly supports the standard.

Always the right data format
To simplify the generation of uniform plans, it was necessary first of all to convert data from different data sources, formats and inspection procedures, and to eliminate errors in the database. The BaSYS PISA rehabilitation module made plausibility checks available that show, among others, differences between the source data recorded during the inspection and the existing master data. Data of all the current standards and regulations from the TV inspections could be taken into account, tested and transformed. This way the ITAS engineers were able to ensure that through adjustment processes all data were indeed fed in without delays.

Perfect for large zones
In the next step, the TV inspections were evaluated and a condition assessment was prepared. The layout of the Volkswagen factory premises with its multitude of branched-off, small-sized structures placed high demands on a network information system. “One of the key criteria for choosing BaSYS PISA was the possibility to comfortably and clearly process large zones with a variety of structures,” says Mr. Papesch (MEng), Managing Director of ITAS Salzgitter GmbH. This is because BaSYS is backed by a sophisticated, powerful database management system with support of spatial geometry data management. This supports more sustainable and system-independent data storage of spatial data, which allows quick access to the topology. With this, branched-off and nested networks with many structures can easily be modelled and processed.

Assistance with classification
Good graphical representation is particularly valuable to illustrate, analyse and assess damage from different perspectives when the visual inspections are evaluated. In BaSYS PISA the ITAS engineers also have direct access to the structural condition assessments according to ISYBAU required by the client. This has improved the efficiency and precision of the condition assessment.

Increasing efficiency in planning
BaSYS PISA allows a clear comparison of the section-related rehabilitation operations of modernisation, renovation and repair. The integrated cost estimate automatically determines the cost of rehabilitation or modernisation. With the planning software, the engineers were able to create several rehabilitation alternatives, while at the same time allocating operations to several damage points and comparing them in terms of cost. “True planning and decision support for complex projects!” says an excited project manager. “The time spent on the planning of sewer rehabilitation have been reduced by 20 per cent since we started using BaSYS PISA,” says Mr. Papesch and adds: “We also provide our clients with great cost consistency and on-schedule reliability.” Because, with the help of BaSYS PISA, workflows for complete rehabilitation design, including comparison and identification of alternative rehabilitation methods, as well as setting priorities and determining the costs of rehabilitation were developed. This way ITAS could make the most cost-effective and technically most rational rehabilitation proposals to the Facility Management department at the Volkswagen plant in Wolfsburg and successfully complete the project.

“With enhanced efficiency, the developed workflows have changed the complete sequence of operations of sewer rehabilitation, from data collection to execution planning and acceptance. In particular, the communication via sub-databases with the client has proven to be a very reliable method.”Dipl.-Ing. Joachim Papesch, Managing Director ITAS