Date Published: 22/07/2022
ARCHIVED - New green filters will remove 60 per cent of nitrates from the Mar Menor
ARCHIVED ARTICLE 8 wetlands will clean contaminated water from the aquifer and eliminate almost a thousand tonnes of nitrates each year
A network of semi-natural wetlands being rewilded around the Campo de Cartagena aim to block the entry of polluted water into the
Mar Menor from the underground aquifer.
Spain’s Ministry for Ecological Transition intends to transform 300 hectares around the Mar Menor lagoon to clean 5.3 cubic hectometres of water that will be pumped from the subsoil per year. This would make it possible to eliminate 968 tonnes of nitrates that are discharged into the lagoon every year, eliminating 60% of these toxic compounds that, together with other elements such as phosphates, cause the proliferation of macroalgae that are dangerous to the ecosystem.
This natural solution promoted by Spain’s central government to lower the water table of the quaternary aquifer under the Mar Menor basin is a departure from the Murcia regional government’s approach. Local authorities instead opted to redirect the groundwater to a plant to eliminate nitrates and reuse the water for irrigation on farmland.
Instead, the eight new wetlands, five of them with associated green filters, will form part of a green belt planned around the Mar Menor to reduce the inflow of pollutants. This was underscored on Thursday afternoon, July 21, when Minister for Ecological Transition Teresa Ribera visited the mouth of the Rambla del Albujón riverbed, where a widening of the final stretch of the riverbed is planned in order to filter the flow from the aquifer and retain runoff during heavy rainfall.
The Ministry is investing more than 450 million euros in this plan, part of which will go towards buying up private farmland or paying the owners ‘rent’ in order to plant suitable plants that will retain and hold back the nitrates.
These actions would begin with the land surrounding the park of Las Salinas de San Pedro and the desalination plant, and then continue with a 44-hectare plot of land in the area of La Calavera de San Javier. The Ministry is also planning other actions in the Rambla de Miranda, Playa la Hita in Los Narejos, in the vicinity of the Los Alcázares treatment plant, Torre del Negro, the Rambla de Ponce in the south of the lagoon and other filters at the mouth of the Albujón.
Image 1: Ministerio para la Transición Ecológica
Images 2 & 3: Zoe Cooper