Hamburg Water Cycle - Jenfelder Au

PROJECT DESCRIPTION

BACKGROUND

Nature follows the circulation principle as does the HAMBURG WATER Cycle: whilst domestic wastewater is usually collected in one pipe, the HAMBURG WATER Cycle separates the wastewater regarding its different characteristics to achieve an ecological and efficient reutilisation. In Hamburg the new district Jenfelder Au comprises around 1 150 apartments, 835 of which will take part in the project. These apartments will be fitted with water-saving vacuum sanitation technology and separate wastewater collection, drainage and treatment systems. The black water stream will be used for energy generation. The grey water will be treated separately with the aim to let it into the nearby river.

OBJECTIVES

The HWC-Jenfelder Au projects overall objective was to demonstrate the technical, environmental and economic feasibility of an integrated and decentralised wastewater disposal and energy generation system for an urban housing district in Hamburg, Germany. The concept brings together well-known technologies, as well as new and innovative prototypes to be demonstrated for the first time on a large-scale. The system would be developed in different phases, in accordance with the different phases of construction.

Specific objectives were to:

Demonstrate an integrated wastewater disposal and energy generation system;

Minimise the dilution of sewage with drinking water (flush) by the use of vacuum toilets within an urbandistrict;

Promote water quality, i.e. preventing rain and greywater from being polluted with black water;

Save energy by systematically treating and utilising separated wastewater streams (this would be done by preventing energy consuming wastewater processing);

Demonstrate an innovative decentralised energy generation concept based on a biogas plant and a combined heat and power plant (the concept planned to demonstrate the potential to minimise the use of non-renewable energy sources and the potential for energy generation based on separation of black water); and

Prepare for future phosphorus and nitrogen recovery and effective elimination of micro pollutants such as pharmaceuticals.

RESULTS

The HWC-Jenfelder Au project demonstrated the technical, environmental and economic viability of an integrated, decentralised wastewater treatment and energy generation concept for Jenfelder Au, a newly constructed urban district in Hamburg. By the end of the project, 120 apartments (around 350 inhabitants) were connected to the wastewater management system that separates black water (from toilets) and grey water. Once the construction works at Jenfelder Au are completed 835 living units (around 2.400 inhabitants) will be connected to the system.

Specific results of the project include:

Operation of vacuum sewer system since 2016 successful;

Treatment of black water since May 2019 with minor disturbances;

Design of the greywater treatment facility and contract with the manufacturer signed;

Creation of a wastewater treatment system that is energy self-sufficient, and even provides a small energy surplus;

Analysis and assessment of ecological and economic parameters;

Increase in organic matter (measured as chemical oxygen demand, COD) from 900 mg/l to 5 220 mg/l (target: 10.000 mg/l);

Saving of 28 344 m3 drinking water following settlement of the area (target: 12 500 m3);

Saving of 13 435 kWhel per year (target: 6 200 kWhel per year);

Saving of 19 000 kWh per year at a central wastewater treatment plant (target: 20 000 kWh);

30% reduction in freshwater consumption through use of vacuum toilets; and

Creation of an operational handbook for the installation of vacuum pipe systems in buildings for other potential users in German and English.

The project attracted interest from water/wastewater utilities and experts worldwide. A similar initiative in Helsingborg, Sweden, has been launched, with a water source separation system expected to be in operation in 2020. A project is also planned for the Dutch district Buiksloterham that will focus on nutrient recovery from black water for around 530 living units.

Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).