Sammelgrube

A Sammelgrube, or collection pit, is an underground storage facility used to hold wastewater from buildings that are not connected to a public sewer system. It collects domestic wastewater, including toilet flushings, bath and kitchen effluents, until it can be removed by an authorized sanitation service. A Sammelgrube does not treat waste on site; it simply stores it until emptied, after which the contents are transported to a proper treatment facility.

Construction and operation are oriented toward creating a watertight, odor- and leak-resistant container. Pits are commonly made from reinforced concrete, brick, or other watertight materials and are designed to be sealed from the surrounding soil. They may include a ventilation opening and an access lid for inspection and pumping. In some designs, multiple compartments or grills are used to help with solids separation, but the system relies on periodic removal of the accumulated sludge and scum.

Maintenance and safety considerations are central to proper functioning. Regular emptying by a licensed contractor is required to prevent overflow, odors, and potential contamination of soil and groundwater. Proper sealing and intact drainage are essential to avoid seepage. Odor control, routine inspections, and timely pumping are important, especially in areas with high groundwater levels or dense populations.

Regulatory and historical context vary by region. Sammelgruben are more common in rural or historic settings and in places without sewer connections. Many jurisdictions encourage or require modernization, favoring alternative on-site systems such as septic tanks with treatment or connections to a sewer network, to reduce environmental and public health risks.