Hemminger Straße in the north of Stuttgart is busy not only at peak times. Approx. 12.000 vehicles drive here on a daily basis - i.a. in the adjacent business park. Due to the traffic load, diverse pollutants that are washed away in the rain collect on the road over time. The polluted rainwater may no longer be discharged directly into the water bodies. It must first go through treatment and retention. On behalf of the urban drainage department of Stuttgart, DAHLEM has designed a cleaning system as a trough-trench system: here, the polluted rainwater is first collected in a shallow, grassy hollow (approx. 500 m²). The accumulated water seeps slowly into the ground. In the process, most of the pollutants contained in the soil layers are filtered out. Under the soil of the trough there is another storage space, which is designed with trenches (250 m³) and ensures that the seeping rainwater can be held back again and introduced as an environmentally friendly inflow into the Lindenbach.
After 26 years of operation, one of the two parallel-fed disc dryers of the sludge drying plant was replaced by a new one at Waste Water Treatment Plant Düsseldorf-Süd. In order to ensure a constant operation of the facilities, the exchange of the other rotor took place already in 2005. Before the replacement of the second rotor, a study showed that the drying of sludge by means of a new disc dryer represented the most favorable solution in terms of operating costs. With a pipe length of 8.6 metres and a heating surface of 400 m², the new disc dryer 2, partly made of stainless steel, provides a throughput of 5.2 tonnes per hour. As the previous plant part was no longer economically viable, the rotor replacement took place in March 2019. For the replacement of the disc dryer, DAHLEM provides the technical equipment planning, from establishing the basis of the project to the award, including construction supervision.