On this page, we compare a septic tank, a biological treatment plant and a holding tank by the published prices and by what each one requires year after year. We install septic tanks (from €2,200 including the tank and installation) and BIO plants (from €1,750), pump them out and maintain them, and we also work with office and warehouse premises.
Šampēteris: detached houses next to offices and warehouses
Šampēteris is a residential and commercial neighbourhood in Pārdaugava, close to the airport and the main roads. Kārļa Ulmaņa gatve, Lielirbes iela and the airport route connect it with the whole city, and the buildings are a mix of detached houses, low-rise buildings, offices, warehouses and retail areas.
The detached-house streets have houses from different periods, so the systems vary: an old concrete septic tank, a newer BIO plant or a connection to the city network. If there is a Rīgas ūdens (Riga's water utility) network in your street, look at connecting first: Riga grants €1,000–2,000 for connecting a residential house, depending on the length of the service pipe, see connecting to the mains sewer.
Septic tank, BIO plant or holding tank: the cost to install and the cost per year
| System | Installation | Per year | What to consider |
|---|---|---|---|
| Septic tank with infiltration | from €2,200 including the tank and installation | pumping at least once a year: from €75 (up to 4 m³) or from €90 (up to 6 m³) | needs free-draining soil and room for the field; works without electricity |
| Biological treatment plant | plant from €1,750 + labour from €800 | maintenance from €160; electricity for the compressor; tests every 2 years | also suitable in clay and with high groundwater; needs an outlet into a ditch or the ground |
| Holding tank | 2 m³ tank from €800; complete set from €2,200 | pumping according to consumption | nothing drains into the ground, but pumping is frequent |
An example for a holding tank: for four declared residents without a water meter, Riga calculates 36.5 m³ a year. A 6 m³ tank then has to be pumped out six to seven times a year, which at the starting price of €90 comes to roughly €540–630 a year. That's why, for a permanent home, a holding tank is usually a temporary solution until there is a network in the street.
A septic tank is the cheapest to run, if the plot allows it. A BIO plant costs more per year, but it treats the water more thoroughly and lets you do without a large drain field. A broader comparison: septic tank or BIO plant.
What we check on the plot before making an offer
- Soil Sand lets water through, clay doesn't. You can see this in a test pit or in the geotechnical report for a new build.
- Groundwater The level measured in spring shows whether a dry layer will remain under the infiltration drains.
- Location and distances Where the tank and the field can be placed in relation to the house, the drinking water well and the neighbour's boundary.
- Outlet For a BIO plant: whether there is a ditch nearby or infiltration into the ground has to be built.
- Access Whether the vacuum tanker will be able to reach the lid all year round.
National regulations allow clarified water from a septic tank to be discharged into the environment only through an infiltration system. The building code states that for up to 5 m³ per day, septic tanks with filtration fields or drains, or factory-made compact plants with an outlet into a ditch or the ground, can be used. More details: septic tank installation and biological treatment plants.
When the old septic tank can no longer cope
The signs are familiar: the septic tank fills up within a few weeks, the yard smells, water stands over the drain field, or water drains slowly in the house. If the tank is intact but the field is clogged, the field alone can be renewed. If the tank is cracked or the groundwater is too high where the field is, it is better to replace the system: old septic tank replacement or septic tank conversion into a BIO plant. A new system is registered with the Riga Housing and Environment Department within a month after it is built.
Offices, warehouses and hospitality
- For hotel and café kitchens: grease trap cleaning from €90.
- For warehouse yards: drainage well cleaning and rainwater drainage.
- For premises with their own tank: pumping for businesses on a schedule and with documents.
The main roads allow access for a larger tanker of up to 10 m³ (from €110), but on the side streets with detached houses, we recommend stating the width of the street and the distance to the lid.
Riga's rules and nearby areas
In Šampēteris, Riga Binding Regulations No. 66 apply: the system must be registered, a septic tank must be pumped out at least once a year, a BIO plant must follow the manufacturer's maintenance intervals, and the volume removed in the previous year must be declared by 1 May. Only a pumping contractor from the Department's register may pump out.
Sources: Riga City Council Binding Regulations No. 66 (points 4.2, 5.4, 5.6, 23 and 26), likumi.lv/ta/id/304471; Cabinet Regulation No. 384 (points 4.4 and 7), likumi.lv/ta/id/291947; LBN 223-15 (point 151), likumi.lv/ta/id/274990; Riga City Council Binding Regulations No. RD-23-207-sn, likumi.lv/ta/id/343520. Checked on 30 October 2026.
Nearby neighbourhoods: Zasulauks, Zolitūde, Bieriņi and Beberbeķi. All areas: where we work.