The cooperation laboratory of the Ruhrverband, Emschergenossenschaft and Lippeverband combines cost-effective and flexible testing, analysis and consulting expertise with the associated scientific know-how in the various areas of water quality management.

The laboratory constantly monitors the water quality in rivers, reservoirs, dams and groundwater on the one hand and the inlet and outlet quality and purification performance of wastewater treatment plants on the other. Analyses of industrial wastewater that is discharged into the public sewer system form the basis for determining the cost contribution for the purification services to be provided by the wastewater treatment plants.

Using modern and powerful analytical instruments, around 600 organic and inorganic substances can currently be detected and quantified in water. Dealing with current issues, such as the analysis of trace substances in our waters, also emphasises the efficiency of the cooperation laboratory. Another important task is the provision of scientific advice by qualified colleagues from the fields of chemistry and biology.

The Ruhr Quality Report, which has been published annually since 1973, has presented the current situation and development of the water and water quality of the Ruhr, its tributaries and the reservoirs in a transparent and comprehensible manner for over 50 years.

Cooperation laboratory accredited by the German Accreditation Body

The cooperation laboratory of Ruhrverband and Emschergenossenschaft / Lippeverband is accredited according to DIN EN ISO/EC 17025:2018 by the Deutsche Akkreditierungsstelle GmbH (DAkkS) in separate accreditation procedures. The accreditation is valid for the scope specified in the accreditation certificate D-PL-19758-01-00.

The certificate confirms the competence of the cooperation laboratory to carry out physical, physico-chemical and chemical analyses as well as bioassays of water (wastewater, surface water and groundwater) in accordance with the standards in the specialist module water. Based on the DAkkS accreditation, the cooperation laboratory was notified and thus recognised as a state inspection body for water and waste monitoring (§125 NWG, §44 NAbfG).

Water biological investigation of the dams

The different uses and tasks of the eight reservoirs of the Ruhrverband place high demands on the management of the reservoirs. The aquatic biological investigations of the water body as well as the inflows and outflows are of particular importance.

The results of these investigations are used for adequate fisheries management, early action in the event of threats to the ecosystem and water utilisation as well as for monitoring and evaluation in accordance with the requirements of the European Water Framework Directive.

To this end, the Ruhrverband carries out a standardised monitoring programme at each reservoir throughout the year, particularly during the plankton and aquatic plant growth period. This monitoring is supplemented by weekly inflow and outflow samples, which are used to determine the nutrient balance (inflow loads, retention). The analysis data obtained is analysed in accordance with the hydrological boundary conditions (e.g. level measurements at the tributaries, reservoir content). Important questions are: How do environmental factors such as temperature, radiation and nutrients control plant growth, e.g. of phytoplankton, and what influence does phytoplankton ultimately have on fish management?

The knowledge acquired over many years has paid off: A stable ecosystem has now become established in all Ruhrverband dams, but one that still needs to be maintained.

Ensuring water quality through comprehensive analyses and innovative processes

The area of wastewater treatment plant monitoring includes checking the quality of the influent with regard to organic contaminants, nutrients such as phosphorus and nitrogen, heavy metals and organic trace substances. The purification performance of individual treatment stages and the entire wastewater treatment plant is also checked. Compliance with the monitoring values specified in the water law notices and in the declarations on the reduction of charges, as well as the values of operating materials, is checked by the analyses of the cooperation laboratory. The regional divisions are supported in the optimisation of wastewater treatment plant operation with tests on precipitation, flocculation or adsorption and investigations of operating resources such as precipitants or external carbon sources. The wastewater analyses carried out by the wastewater treatment plant operation department using simplified measurement methods such as cell tests and online analysis are quality-assured through extensive support and comparative measurements.

In the event of malfunctions, especially in the case of unauthorised discharges, investigations are carried out to determine the causes and identify the polluter, including event-driven sampling and sampling in the sewer network. In order to obtain more detailed and water body section-specific information on the emission and immission situation, combined investigations of wastewater treatment plant inflow and outflow as well as in the water body upstream and downstream of the respective discharges are becoming increasingly important. In connection with the extension of water discharge permits for wastewater treatment plants, these measurement programmes are, among other things, an important evaluation aid for the targeted derivation of discharge requirements for wastewater treatment plant discharges. Studies are now also being established for the preparation and commissioning of 4th purification stages at wastewater treatment plants.

Review of water quality and water quality in the Ruhr catchment area

The Ruhr is of particular importance in its dual function as a drinking water reservoir and wastewater outfall. Its investigation is important for characterising water quality and water quality as well as for monitoring the success of water management measures.

Here, chemical-analytical data on water quality, which primarily describe the situation at the time of sampling, and the biological assessment based on the organisms living in the water, which on the one hand reflect the effects of all possible pollution factors and on the other hand illustrate their effects over time, complement each other perfectly.

In water monitoring, various measurement programmes record both temporal and local changes in water quality. Since the 1920s, samples have been taken at close intervals in Essen-Rellinghausen ("Zornige Ameise") as a reference measuring point. In addition, monthly longitudinal analyses of the Ruhr are carried out at twelve sampling points and (at different intervals) in the tributaries. Water biological inventories of the aquatic biocoenoses in the Ruhr and its tributaries, supplemented by physico-chemical analysis data, form the basis of the water status map of the catchment area.

Several monitoring stations along the Ruhr are used to detect water pollution as quickly as possible and, if necessary, to warn downstream drinking water works. Depending on the type and extent of the contamination, countermeasures may be initiated. The laboratory can also monitor the situation using measurement technology (including retained samples) in order to determine the causes and polluters.

In order to obtain more detailed and section-specific information on the emission and immission situation, combined analyses of wastewater treatment plant inflow and outflow as well as in the water body upstream and downstream of the respective wastewater treatment plant discharge are becoming increasingly important. Such analyses enable statements to be made about the origin of trace substances and nutrients and their significance for the chemical status of water bodies as well as for possible effects on the ecological situation in the water body. In addition, they form the basis for substance flow modelling, which in turn serves as an instrument for selecting measures in management planning.

In instrumental analysis, samples from wastewater and water monitoring are prepared and analysed. This requires modern measuring equipment and specialised staff in order to meet the tasks and the increased demands on sample preparation and measuring technology and their detection sensitivity.

The work is often complex due to the influence of the accompanying substances and the low concentrations (down to the low nanogram range, i.e. billionths of a gram) and is comprehensively accompanied by quality assurance measures.

The majority of measurements are carried out according to standardised procedures (e.g. DIN and ISO). In-house methods have been developed for the detection of some substances. Plasma technology (ICP-OES, ICP-MS) is primarily used to determine elements. Organic compounds, which have very different volatilities and polarities, are analysed using gas chromatographic (GC) and liquid chromatographic (LC) separation methods.

The analysed variables include sum parameters such as TOC, TNb, AOX or mineral oil hydrocarbons (MKW). The scope of organic trace substances includes, for example, volatile components, pesticides, flame retardants, plasticisers, synthetic complexing agents, polycyclic aromatics, perfluorinated compounds (PFAS), active pharmaceutical ingredients and diagnostics as well as industrial chemicals. A total of around 600 individual compounds, metals and sum parameters can be analysed, with the number of substances analysed constantly increasing.