How we compared
We took plants offered in Latvia for private houses and compared models for 4–6 people. We used only what the manufacturer or the official distributor publishes itself. If a figure is not given in the documents, we say so in the table. Prices and documents change. All data were checked on 30 October 2026.
We install and service plants from various manufacturers, so this page is not an advertisement for any brand. If you are interested in another brand, mention it in your request.
The key facts in a table
| AUGUST AT | PURA | AQUABLOC | Traidenis NV | |
|---|---|---|---|---|
| Manufacturer according to the documents | UAB “AUGUST ir Ko”, Lithuania | UAB “Plastic Technology”, Lithuania | P.P.U.H. Wojciech Tycner, Poland | UAB “Traidenis”, Lithuania |
| Technology | Activated sludge, continuous flow; zones in one tank | Activated sludge; 4 chambers: anaerobic, denitrification, nitrification, secondary settling tank | SBR (batch process), 8-hour cycle in one chamber | Activated sludge with biofilm carriers; 2 chambers in one tank |
| Tank material | Polypropylene | Polypropylene | High-density polyethylene, monolithic 2,000–4,000 l tanks | Fibreglass |
| Models for ~4–6 people | AT-6: 1–4 people, 0.6 m³/day; AT-8: 1–6 people, 0.9 m³/day | PURA 4: 2–4 people, 0.6 m³/day; PURA 6: 4–6 people, 0.8 m³/day | 0.45: 1–4 people, 0.45 m³/day; 0.75: 4–6 people, 0.75 m³/day | NV-1a…NV-4a; capacity given as an image on the page |
| Electricity | The seller states an average of ~270 kWh a year for the AT series | Not stated in the documents | 0.42 (0.45) and 0.55 (0.75) kWh/day; in holiday mode 0.17–0.24 | No figures stated |
| Sludge removal | Concentration measured every 6 months; removed if above 600 ml/l | At least every six months, every 2 months recommended | At least once every 2 years, once a year recommended | 2/3 of the volume is pumped out; frequency not stated on the page |
| Maintenance | Filter every 6 months, membrane after 1 year | Professional maintenance at least 2 times a year | Service timers: plant 365 days, compressor 7,000 h | Not stated |
| Holiday mode | HOLIDAY, WEEKEND HOUSE | Not stated | Holiday mode (at least 14 days) | Not stated |
| Standard stated by the manufacturer | EN 12566-3:2005+A2:2013 | EN 12566-3:2005+A2:2013 | PN-EN 12566-3+A2:2013 | Not stated on the page |
| Published price incl. VAT | AT-6 €1,720, AT-8 €1,930 | PURA 4 €1,694, PURA 6 €1,936 | Not published on the official page | Not published |
Sources: AUGUST technical passport and series page at lzt.lv; PURA product page and technical passport at ecotehnologijas.lv; AQUABLOC user manual in Latvian (aquabin.pl, 2026); Traidenis manufacturer's page at traidenis.lt. Prices are given as published on the distributors' pages. Checked on 30 October 2026.
AUGUST AT
AUGUST AT series plants are sold and serviced in Latvia by LZT. A single polypropylene tank holds an anaerobic zone, an aeration zone and a secondary settling tank; three air-driven jet pumps move the sludge between the zones, and a solids bag holds back the solid particles. The compressor can be placed up to 5 m from the plant. The series comes in AT (standard), ATK (lid at lawn level), AT PLUS (with an automatic controller) and AT GB (for installation in concrete rings under a roadway) versions.
The controller described in the passport has programmes for holidays and for a summer house, and it signals a compressor fault or a power failure with a light and a sound. With high groundwater, the tank must not be emptied completely. For maintenance, read AUGUST AT-6 maintenance.
PURA
PURA plants are offered in Latvia by SIA “Eco tehnoloģijas”, which describes itself as the manufacturer's official distributor. The plant has four chambers with sludge recirculation; the air blower is built into the lid or housed in a separate box. The model range goes up to 7.5 m³ a day and 50 people.
The passport states: with high groundwater, the tank is anchored to a concrete slab; under a roadway, a concrete slab at least 150 mm thick is needed above it. Start-up can be postponed by up to two months if the daytime temperature is below +10 °C and the night-time temperature below 0 °C. We describe maintenance on the page PURA treatment plant maintenance.
AQUABLOC (Sotralentz)
In Latvia, AQUABLOC is offered under the Sotralentz name; the manual names BISTON SIA as the official distributor. The plant works on the SBR principle: the whole process (aeration, settling, pumping out the treated water) takes place in one tank in 8-hour cycles. The tanks are monolithic, 2,000–4,000 l; the largest models use two.
The control unit checks the compressor and the valves by itself at least once a day. The optimal installation depth is 20–40 cm, the maximum is 60 cm. The manufacturer recommends regular use of biological activators and warns that an empty tank can deform under soil pressure. For more on bacteria, read bacteria for biological treatment plants.
BIO-VIDE and other installers
BIO-VIDE is a Latvian installation and maintenance company, not a manufacturer. On 30.10.2026 its website did not name a specific plant brand or model, so we don't include it in the table. The same is true of many installers: a plant may be offered under the installer's own name. In that case, ask for the manufacturer's name, the technical passport and the EU declaration of conformity.
Are there biological treatment plants made in Latvia?
For the brands we checked, the documents name companies in Lithuania and Poland as the manufacturers; Latvian companies sell, install and service them. That doesn't mean there are no plants made in Latvia. If origin matters to you, ask the seller for the declaration of performance or the EU declaration of conformity. It must include the manufacturer's name and address.
What to compare before you buy
- Number of people and daily flow: calculate from your actual water consumption, not just the number of residents.
- Where you will discharge the treated water, and whether that is permitted where you live.
- Groundwater: whether the plant has to be anchored and whether a pump well is needed.
- Electricity consumption, and where the compressor will be located.
- Maintenance intervals and who will carry out the maintenance. Some manufacturers provide that maintenance is done only by an authorised service.
- Holiday mode, if the house is a summer house.
- A technical passport in Latvian, which is also needed for registration with the municipality.
National regulations require a BIO plant to have the conformity documents set out in legislation and to be operated according to the manufacturer's technical documentation. Source: Cabinet Regulation No. 384, points 4.3.1 and 4.3.2 (likumi.lv). Checked on 30 October 2026.
About online feedback on BIO plants
Read online feedback critically. Manufacturers' instructions name incorrect use (fats, wipes, chemicals, rainwater) and missed maintenance as the causes of smells, cloudy water and foam. So before you buy, ask who will service the plant in your neighbourhood and how quickly spare parts, such as compressor membranes, are available.
Sources
- AUGUST: manufacturer UAB AUGUST ir Ko (Lithuania), technology, polypropylene, kWh, sludge >600 ml/l, filter 6 months, membrane 1 year, HOLIDAY/WEEKEND HOUSE, EN 12566-3, compressor up to 5 m, partial emptying checked 30 October 2026
- AUGUST AT models, number of people, m³/day, prices incl. VAT, ~270 kWh a year, versions AT/ATK/AT PLUS/AT GB checked 30 October 2026
- PURA models, prices incl. VAT, 4 chambers, polypropylene, EN 12566-3:2005+A2:2013 checked 30 October 2026
- PURA: manufacturer UAB Plastic Technology, sludge at least every six months, maintenance 2 times a year, anchoring, 150 mm slab, start-up postponed in cold weather checked 30 October 2026
- Eco tehnoloģijas - official PURA distributor (by its own account) checked 30 October 2026
- AQUABLOC: manufacturer P.P.U.H. Wojciech Tycner (Poland), distributor BISTON SIA, SBR 8 h cycle, PEHD 2000–4000 l, kWh table, holiday mode, service timers, depth 20–60 cm, activators, PN-EN 12566-3 checked 30 October 2026
- Traidenis NV: fibreglass, 2 chambers in one tank, activated sludge with biofilm carriers, models NV-1a…NV-4a, 2/3 of the volume pumped out checked 30 October 2026
- BIO-VIDE - installer, brand not stated on the page checked 30 October 2026
- Cabinet Regulation No. 384, points 4.3.1–4.3.3: conformity documents, operation according to the manufacturer's documentation, maintenance by a suitable company checked 30 October 2026