Sewage treatment plants in Sóller, for the valley homes beyond the mains

Your area

The Sóller valley: mains sewer in the villages, own treatment on the fincas

The rules are the Balearic Islands Water Plan (Royal Decree 49/2023, art. 70), as everywhere on the island. Three things are different in Sóller.

Where there is a sewer and where there is not

The environmental assessment in Sóller's Local Agenda 21, by the town hall (with figures from 2004 to 2007), places the sewer network in three settlements (Sóller, the Port and Biniaraix, a little over 16 kilometres in all) and lists, among the points to improve, that many homes on rural land are not connected. That is the case for many of the orchard and mountain houses in the valley: there the wastewater is treated on the plot, with an approved unit.

A valley of wells

The same assessment counts one registered well for every 35 inhabitants, more than a third of them for domestic use. In addition, the Balearic government lists about ten public-supply boreholes in the valley (IDEIB viewer, Water Plan supply-boreholes layer), with their protection zones: inside the strictest one, the plant includes denitrification and disinfection (art. 70.10, table 13). With so many wells nearby, we first look at where the water goes and what lies around the house.

Serra de Tramuntana: natural area and aquifer

The mountains around the valley are part of the Serra de Tramuntana Natural Area, declared in 2007; its natural resources management plan was approved by Decree 19/2007. If the finca lies within it, your architect or engineer also checks what that plan says. And on the government aquifer vulnerability map, there are areas of high vulnerability around the Port and in parts of the valley, where the rules only allow discharge to a green area, with denitrification and disinfection (art. 70.10, table 13).

The paperwork

Which paper applies on a finca in Sóller

With the water reused in the orchard or the garden, the responsible declaration to the Direcció General de Recursos Hídrics (DGRH), once the unit is installed (art. 70.4). If the house is still being built, the prior notice goes to Recursos Hídrics first (Sóller town hall asks for it), and from then there are two years at most to file the declaration (art. 70.5). If the water goes to a drainage trench or soakaway well, prior authorisation.

As the installation company we prepare and sign the documents for the unit (technical data, the manufacturer's performance figures, maintenance plan, proof of purchase and installation, and the electrical installation certificate), and your architect or engineer files them.

Sources: Balearic Islands Water Plan, RD 49/2023 (art. 70) · wetland catalogue, supply boreholes and aquifer vulnerability in the Balearic government IDEIB viewer · Sóller Local Agenda 21, environmental assessment (Sóller town hall) · Serra de Tramuntana Natural Area (CAIB).