Sewage treatment plants in Mallorca
Septic tank, treatment plant or holding tank, the documents and maintenance, in detail.
See the guide →Treatment plants · Andratx
Sewage treatment plants in Andratx: treat your household water and irrigate with it
In Andratx there are homes off the mains in the Serra, around s'Arracó and in villas that live on a well or on water trucks. Here the household water, properly treated, is irrigation water that does not come out of the aquifer. 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.
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- New approved unit
- Signed documents
- Treated water for irrigation
- Since 1998
Your area
What the Water Plan says about the water in Andratx
Three groundwater bodies in the municipality —Coll Andritxol, Port d'Andratx and Ses Basses— are listed in poor status in Annex 9 of the Water Plan. That weighs on how each house treats its water.
Port d'Andratx: more goes out than comes in
The Port d'Andratx groundwater body (1801M2) is abstracted at 104 % and has 290 mg/l of chlorides from seawater intrusion. The Plan asks to cut pumping for scattered use and to replace well water sold by truck with the ABAQUA network. Reusing treated water in your garden, as art. 70.12 requires with 25 m² of green area per population equivalent, is irrigation that does not come out of that aquifer.
Rock and gypsum under the Serra
The Plan describes these aquifers as Jurassic limestone and dolomite, with Keuper gypsum in places. For the works it means your builder may hit rock when digging the pit: before anyone digs, we give them in writing how the pit must be according to the manufacturer of the unit.
Hillside estates
On a sloping plot, art. 70.7 requires the site of the system to take into account the ground, the slope and its position relative to the house. If there is no room for the treated water, the Plan provides for a sealed holding tank emptied periodically (art. 70.2.a).
Sources: Balearic Water Plan, Royal Decree 49/2023 (regulations, art. 70, 71, 76 and 77) · Annex 9 of the Plan, entries for the groundwater bodies “Port d'Andratx (1801M2)”, “Coll Andritxol (1801M1)” and “Ses Basses (1801M4)” · EN 12566 · manufacturer's manual (GRAF one2clean, as an example).
The rules here
Holiday homes and large villas
Many houses in Andratx are closed part of the year. The treatment plant is sized for the maximum number of people, not the average, and the blower is not switched off when you leave. In seasonal homes where treatment is not feasible, the Plan accepts a sealed holding tank (art. 70.2.b).
If the villa has more than 12 population equivalents (in a home, the Plan's guideline equivalence is one per bed space, art. 70.8), the performance checks and the maintenance and sludge log must be sent to the DGRH every year (art. 70.11), and the pre-treatment includes grease removal (table 14).
What we do
What we do in Andratx, and what others do
- A unit sized for the most people, not for the average of a house that stands empty for months: new, approved with CE marking and EN 12566. We work with all brands; for example, the GRAF one2clean with its Pack +C for absences.
- The pit in the Serra is dug by your builder, who may find limestone, dolomite or gypsum; beforehand we give them in writing, according to the manufacturer, how to leave it on a sloping plot. The sludge is emptied by an authorised waste company (art. 70.7.f).
- Installation, electrics and starting the blower, which in Andratx is not switched off when the house closes for the season. We do it ourselves, as a licensed low-voltage installation company. We don't subcontract anyone.
- The paperwork, large villas included: above 12 bed spaces, the declaration is followed every year by the performance check and the sludge log (art. 70.11). We prepare and sign it as the installation company; your architect or engineer files it.
- Maintenance between seasons: 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, also in houses that stand closed part of the year.
How we work
How we do it in Andratx, in 3 steps
1
Tell us how the house is used
Location, maximum bed spaces and whether people live there all year or only in season: that decides between a treatment plant and a holding tank (art. 70.2.b).
2
A quote made for the slope
In writing: the unit, the blower supply, where you irrigate the 25 m² per population equivalent and how the pit must be left on sloping ground.
3
Installation in Sant Elm, s'Arracó or the Serra
We install once the pit is dug, start the plant and leave the signed documents for your engineer to file with the DGRH. From then on, treated water irrigates without drawing on the well or the tanker.
Keep learning
More on treatment plants and energy in Andratx
The general guide to treatment plants and what else we do in your area.
Solar panels in Andratx
Self-consumption for the house, the treatment plant blower included.
See solar in Andratx →Heat pumps in Andratx
Heating and hot water with a heat pump.
See heat pumps in Andratx →Across Mallorca
Sewage treatment plants by area (west and centre): Palma · Calvià · Llucmajor · Marratxí · Santa Maria del Camí · Binissalem, or see the guide to sewage treatment plants in Mallorca →
Need the house drainage (downpipes, rainwater, chambers)? Drainage in Mallorca →
Also in Andratx: air conditioning · EV charger installation
See our work and customer reviews on the JSL Google Maps profile →
Common questions
Frequently asked questions about treatment plants in Andratx
Why is treated water a resource in Andratx?
Because the Port d'Andratx aquifer is abstracted at 104 % and has 290 mg/l of chlorides, according to Annex 9 of the Balearic Water Plan, which asks for less pumping. The general rule is to reuse treated water on your plot, with 25 m² of green area per population equivalent (art. 70.12): irrigation that comes neither from the well nor from the truck.
My house is on a slope and I have hardly any flat garden. What can I do?
The site of the unit has to suit the slope and the ground (art. 70.7 of the Balearic Water Plan, Royal Decree 49/2023). If you do not reach 25 m² of green area per population equivalent, the option the rules provide is a sealed holding tank emptied periodically (art. 70.2.a), or a drainage trench with a favourable report and prior authorisation.
My house in Sant Elm stands empty for months: treatment plant or holding tank?
If treatment is feasible, a treatment plant, but with the blower left running: without air the bacteria die. For such houses there are units that feed carbon while nobody is there (on the GRAF one2clean, for example, the Pack +C). If use is so seasonal that treatment is not feasible, the Plan accepts a sealed holding tank (art. 70.2.b of the Balearic Water Plan, Royal Decree 49/2023), emptied completely each time.
I have a villa with 14 bed spaces in Andratx. What applies to me?
In a home, the Plan's guideline equivalence is one population equivalent per bed space (art. 70.8 and table 12 of the Balearic Water Plan, Royal Decree 49/2023), so that is 14: above 12, the pre-treatment includes grease removal and the performance checks and the cleaning, maintenance and sludge log go to the DGRH every year (art. 70.11). With 12 or more, inside a public supply well perimeter or 500 m or less from a wetland, a prior authorisation is needed.
What if we hit rock when digging the pit?
The excavation, the sand bed and the backfill are done by your builder. Before they dig we give them in writing how the pit must be according to the manufacturer, because a badly bedded tank loses the manufacturer's warranty. In Andratx the Balearic Water Plan (Royal Decree 49/2023) describes the subsoil as limestone and dolomite, so it is worth planning for.
My house in Andratx is under construction. When are the documents filed?
If it is a new build on urban land with no mains sewer, a prior notice goes first to the Balearic water authority, Recursos Hídrics, which is what the town hall asks for before granting the licence (fourth transitional provision of the Balearic Urban Planning Act, Law 12/2017), and, from then, there are at most two years to file the responsible declaration with the DGRH (art. 70.5 of the Balearic Water Plan, Royal Decree 49/2023). As the installation company we prepare and sign the documents, and your architect or engineer files them.
Quality
We work with all brands
As an example, GRAF tanks. We propose the unit for each house and what the area requires.
A house in Andratx with no mains sewer?
Send us the location, the bed spaces, whether it is a holiday home and a few photos of the spot. We reply within 24-48 hours on working days.