BRA SMÅ AVLOPP En utvärdering av anläggningar för enskilda avlopp / Evaluation of small wastewater treatment systems
The purpose of the project “Bra Små Avlopp” or “Small Well functioning Sewage plants” was to evaluate and demonstrate new solutions for decreasing the discharges from on site wastewater treatment plants. Seven of the investigated facilities were package plants, two were urine separating plants with large sand filters, two had septic tanks to collect wastewater separated from toilets and compact sand filters, and, finally, four had chemical precipitation in combination with large sand filters. All of the systems have shown that they are able to remove more than 90% of the phosphorus and more than 90% of the organic matter. The sorting systems also give very low local emissions of nitrogen. To guarantee that the package plants perform well and manage to fulfil high reduction demands, there is a need for well functioning organisations for supervision and operation. The source separating systems require well-informed and motivated users to achieve low discharges.