An employee of the district administration office, who was on duty around the clock as part of theon-call service of the environment department, was informed immediately after the report. He immediately went to Sersheim and checked the situation together with the police and the responsible fisheries inspector. As an immediate measure, the plant operator had the drainage ditch upstream of the inlet to the Metter secured with an earthwork crossbar. The collected fermentation residue was pumped out immediately.
No danger to people - no measures required
Meanwhile, there was no danger to the population at any time. Accordingly, there are no special rules of conduct. The responsible fisheries inspector was informed immediately and contacted the local fishing clubs and fishing rights holders.
Initial measurements at the discharge point revealed no noticeable differences between the upper and lower reaches. Nevertheless, a clear impairment of the water was visible downstream, particularly at the level of the Fesslermühle: foaming, reduced oxygen content and increased conductivity were observed. One dead fish was recovered at a hydroelectric power plant, and on Saturday around 60 more dead fish were removed from the Fesslermühle impoundment. Fish deaths were also reported from Sachsenheim and Bietigheim.
The district office carried out several on-site inspections in the days that followed. On May 2 and again on May 5, checks were carried out to ensure that the fermentation residues on the biogas plant site and in the ditch system had been completely removed. While the trench system was found to be clean, residues of the fermentation substrate were still found on the plant site. The crossbar has since been removed so that the drainage system is once again functioning properly.
Incident will be investigated and legally assessed
A further on-site meeting with the manufacturer of the biogas plant and an expert is planned in order to determine the exact cause of the technical defect. The district administration office will be involved
. The case has also been handed over to the public prosecutor's office in Heilbronn, which is examining the next steps.
The exact amount of fermentation residue that got into the Metter cannot be determined - it is estimated to be around 50 cubic meters. Due to the continuous supply of water from unaffected sections upstream of the discharge point, the water was clear again relatively quickly. However, complete ecological regeneration, especially of the fish fauna and microorganisms, will take some time.
