Sewage treatment plants in Mallorca
Septic tank, treatment plant or holding tank, the documents and maintenance, in detail.
See the guide →Treatment plants · Alaró
Sewage treatment plants in Alaró, above the aquifer half the Raiguer drinks from
The village of Alaró treats its waste water at its own treatment works; the mountain fincas and the country houses, on rural land, have no mains sewer, and according to the 2025 INE gazetteer 951 of the 6,172 residents live scattered outside the village. Underneath lies the Penyaflor aquifer, which supplies Alaró, the neighbouring villages and, in part, Palma. We are Joaquín and Juan, installers in Mallorca since 1998: we supply the new treatment plant, install it, do the electrics and prepare and sign the documents for your architect or engineer to file.
Send us photos and details · Reply within 24-48 hours on working days · We assist you in English, Spanish and German
- New approved unit
- Signed documents
- Supply wells, checked
- Since 1998
Your area
Alaró and the Penyaflor aquifer
The data sheet for the Penyaflor groundwater body (1809M2), in Annex 9 of the Balearic Water Plan, describes what lies under Alaró. It is worth knowing before choosing a unit.
Limestone and dolomite: rock
Penyaflor is an aquifer of 45 km², on the southern slope of the Serra de Tramuntana, made up of Jurassic limestone and dolomite and Oligocene conglomerates. In practice, on many plots the pit for the treatment plant is dug in rock: your builder should know that before excavating. We give them in writing how it has to be left according to the manufacturer.
An aquifer abstracted at 103%
According to the Plan, Penyaflor contributes to Palma's supply as well as that of Alaró, Binissalem, Consell and Lloseta, and more is taken out than is replenished: the abstraction index is 103%. Where there are supply wells there are protection perimeters, and inside the maximum-restriction one the treatment plant includes disinfection and denitrification (art. 70.10, table 13).
Fincas in the Serra
A mountain finca usually has little soil and a lot of slope. The rule is to reuse the treated water on the plot, with 25 m² of green area per population equivalent (art. 70.12); if that isn't available, what remains is the sealed holding tank or, with a favourable report and prior authorisation, the drainage trench.
Sources: Balearic Water Plan, Royal Decree 49/2023 (regulations, art. 70 and 71) · Annex 9 of the Plan, data sheet for the groundwater body “Penyaflor (1809M2)” · EN 12566 · manufacturer's manual (GRAF one2clean, as an example).
The rules here
The paperwork in Alaró, and who files it
The treatment plant of a house with no mains sewer is declared to the Balearic water authority (the Balearic Government's Direcció General de Recursos Hídrics) with a responsible declaration: proof of purchase and installation, technical specifications, performance and maintenance plan (art. 70.4). If the house is under construction, the prior notification goes first and then there are at most two years for the declaration (art. 70.5).
With 12 population equivalents or more, if the plot is inside the restriction perimeter of a supply well or 500 m or less from a wetland, a prior authorisation is needed. As the installation company we prepare and sign the documents your architect or engineer asks for; your architect or engineer files them.
What we do
What we do in Alaró, and what others do
- Digging into rock: under Alaró lie the limestones and dolomites of Penyaflor, and the pit is often opened in stone. Your builder digs it to the dimensions we give in writing according to the manufacturer; the sludge is emptied by an authorised waste company (art. 70.7.f).
- A new treatment plant, approved with CE marking and compliant with EN 12566 (art. 70.14). If the estate falls inside the maximum-restriction perimeter of a supply well, it includes disinfection and denitrification. We work with all brands; as an example, the GRAF one2clean.
- Installation, electrics and commissioning on the estate, on a slope and with little flat ground too, as a licensed low-voltage installation company. We don't subcontract anyone.
- The documents for Recursos Hídrics: a responsible declaration if the water irrigates the plot; prior authorisation, with a favourable report, if it goes to a drainage trench. We prepare and sign them as the installation company, and your architect or engineer files them.
- The services required by the rules or, if the manufacturer asks for more, the manufacturer's (on the GRAF one2clean, twice a year), with a signed report. If your house drinks from a well or a cistern, all the more reason to keep it up to date.
How we work
How we do it in Alaró, in 3 steps
1
Location and nearby wells
Send us where the estate is, the bed spaces, which wells are nearby and photos. We check on the DGRH map viewer whether it falls inside a Penyaflor protection perimeter.
2
A quote with the pit in rock
We give you in writing the unit, installation, electrics and documents, and your builder the dimensions of the pit and the backfill according to the manufacturer.
3
Installation and hand-over to your engineer
Once the pit is open we install, commission and hand over the signed documents. If the house is under construction, after the prior notification there are two years at most to declare it (art. 70.5).
Keep learning
More on treatment plants and energy in Alaró
The general guide to treatment plants and what else we do in your area.
Solar panels in Alaró
Self-consumption for the house, the treatment plant blower included.
See solar in Alaró →Heat pumps in Alaró
Heating and hot water with a heat pump.
See heat pumps in Alaró →Across Mallorca
Sewage treatment plants in the Raiguer and the Tramuntana: Consell · Sencelles · Selva · Bunyola · Esporles, or see the guide to sewage treatment plants in Mallorca →
And for the summer: air conditioning in Alaró →
Need the house drainage (downpipes, rainwater, chambers)? Drainage in Mallorca →
Sewage treatment plants near Alaró: Binissalem · Lloseta · Santa Maria del Camí
See our work and customer reviews on the JSL Google Maps profile →
Common questions
Frequently asked questions about treatment plants in Alaró
Why does the Penyaflor aquifer matter for the treatment plant on my finca in Alaró?
Because Alaró, Binissalem, Consell, Lloseta and, in part, Palma are supplied from it, and the Balearic Water Plan (Royal Decree 49/2023, Annex 9) rates it in poor quantitative status, with abstraction at 103%. Where there are supply wells there are protection perimeters; inside the maximum-restriction one the unit includes disinfection and denitrification (art. 70.10). We check it on the DGRH map viewer with your location.
My plot in Alaró is solid rock: can the treatment plant be installed?
Yes. The Penyaflor aquifer is limestone and dolomite, according to Annex 9 of the Water Plan, and it is normal for the pit to be dug in rock. The excavation is done by your builder; beforehand we give them in writing the dimensions of the pit and how it is backfilled, according to the manufacturer's manual. We install the unit, approved in accordance with EN 12566, and the electrics.
I have a mountain finca with little flat ground: what do I do with the treated water?
The rule is to reuse it on the plot, with 25 m² of green area per population equivalent (art. 70.12 of the Balearic Water Plan, Royal Decree 49/2023). If that ground isn't available, there is the sealed holding tank emptied periodically (art. 70.2.a) or the drainage trench, which needs a favourable report and prior authorisation, whatever the number of bed spaces.
Is the treatment plant on my finca processed at Alaró town hall?
The responsible declaration for the treatment plant is filed with the Direcció General de Recursos Hídrics of the Balearic Government (art. 70.4 of the Balearic Water Plan, Royal Decree 49/2023), not at the town hall. As the installation company we prepare and sign the documents; your architect or engineer files them, together with whatever the building licence requires.
What maintenance does a treatment plant need on a finca in Alaró?
The servicing the regulations set or, if the manufacturer asks for more, the manufacturer's: on the GRAF one2clean, as an example, two a year according to its manual, with a signed report. The sludge is emptied by an authorised waste management company (art. 70.7.f). If the house is used seasonally, the important thing is not to cut the power to the treatment plant. And if you drink from a well or a cistern, like a good share of the houses outside the village according to Alaró's energy and climate plan, all the more reason to keep it up to date.
Does a house with 5 bed spaces in Alaró need authorisation, or is the declaration enough?
Below 12 population equivalents (in a home, one per bed space) and reusing the water on the plot, the responsible declaration is enough (art. 70.4 of the Balearic Water Plan, Royal Decree 49/2023). A prior authorisation is needed if the water goes to a trench or a soakaway, whatever the number of bed spaces.
Quality
We work with all brands
As an example, GRAF tanks. We propose the unit for each house and what the area requires.
A finca in Alaró with no mains sewer?
Send us the location, the number of bed spaces, which wells are nearby and a few photos. We reply within 24-48 hours on working days.