I’Ons, D., Mattsson, A., Davidsson, F., Mattsson, J., Gryaab AB, Sweden(free)
Abstract REVAQ is a voluntary certification system used to regulate the application of wastewater sludge on agricultural land in Sweden. The system ensures that nutrients from wastewater fractions can be sustainably reintroduced to agricultural land in accordance with national environmental regulations and goals. The system provides stakeholders with information regarding the composition and end use of the sludge and sets guidelines for the continuous improvement in the quality of influent wastewater and sludge with respect to metals and other prioritised substances.
The REVAQ system started in 2002 as a development project involving Swedish Water, LRF (The Federation of Swedish Farmers), Lantmännen (agricultural supplier cooperative) and grocery chains. Swedish Water is the sole owner of the system today in its current form. Currently half of the sewage sludge produced in Sweden is produced at plants with REVAQ certification.
The Rya WWTP, which is one of Sweden’s largest wastewater treatment plants, has been licensed according to REVAQ since 2009. The quality, quantity and common end use methods for sewage sludge in Sweden compared to the EU are summarised. The requirements needed to qualify as a REVAQ plant, the activities required to maintain the certificate and experiences and challenges regarding the production and end use of REVAQ sludge are also described.
Keywords: Agriculture, environmental pollutants, heavy metals, recycling, regulatory system, REVAQ, wastewater sludge nutrients.