Since March 2025, Ādaži Municipality has new rules on decentralised sewage systems, with specific requirements both for how a septic tank is built and for every pumping, and below we explain them in practical terms. Pumping a septic tank of up to 4 m³ costs from €75, and outside Riga a travel charge of ~€1/km is added.
Ādaži: new neighbourhoods, low-lying land by the Gauja and the lakes
Ādaži is a suburb north-east of Riga where, next to the older housing, many new detached houses, terraced houses and apartment projects have been built in recent years. Some streets are connected to the town networks. In detached-house neighbourhoods with no mains network, wastewater is collected by a septic tank, a holding tank or a biological treatment plant.
The ground here is not the same everywhere. Near the Gauja and the lakes, and in wooded, lower-lying spots, groundwater can rise close to the surface in spring, while on sandier plots water soaks away quickly. So on one street a septic tank with a drain field works well, but a few streets away you need an anchored tank or a BIO plant. What decides it is the soil on the specific plot, not the address.
This page is about the town of Ādaži and the built-up areas close to it. The municipality also has coastal villages, rural areas and military areas where access and working conditions are different; we clarify those after your request.
A new house in Ādaži: what kind of septic tank the municipal rules require
Ādaži Municipality Binding Regulations No. 3/2025 set technical requirements for a septic tank that you need to know as early as choosing the tank. The septic tank must be watertight, with two or more chambers, and its volume must be at least three times the average daily volume of wastewater, but not less than 1 m³. If a family uses about 0.5 m³ of water a day, the septic tank needs at least 1.5 m³; in practice people choose a larger tank with spare capacity for sediment.
Settled liquid from a septic tank may only reach the environment through an infiltration system, which Cabinet Regulation No. 384 also requires. If the plot is low and water stands on it in spring, a drain field may not work. Then what remains is a BIO plant discharging into a ditch or a sealed holding tank. How a plastic tank is secured against floating up is covered on the page septic tank for high groundwater.
One Ādaži requirement for new builds is often missed: a new system may only be used after it has been registered. So it is worth submitting the registration declaration straight after installation, not after you move in. On planning the system for a new house: sewerage for a new build. Septic tank installation with the tank starts from €2,200.
Ādaži Municipality rules: register, pumping and pumping contractors
| Question | How it works in Ādaži Municipality |
|---|---|
| Who keeps the register | The municipal agency Carnikavas komunālserviss, for the whole municipality since 01.03.2022. |
| How to register | System registration declaration (Annex 1 to Binding Regulations No. 3/2025): in person in Ādaži or at the agency in Carnikava, by post, via latvija.gov.lv or by e-mail with a secure e-signature. Free of charge, registered within a month. |
| Septic tank | Pumped once a year, removing at least 70% of the working volume each time. |
| Holding tank | The frequency is calculated by dividing water consumption by the tank volume (rounded down), but no less often than once a year. Without a water meter, 1 m³ per person per month is assumed. At least 70% is removed each time. |
| BIO plant | Maintenance according to the manufacturer's documentation; a copy of the maintenance certificate is submitted to the agency within a month of each service. |
| Documents | Keep receipts or invoices showing the address, volume, amount and date for at least 2 years. |
| Pumping contractor | Registered with the municipality only; the agency's list has 19 companies. |
Two requirements in Ādaži are stricter than in many other places. The first is the 70% threshold: if only the top layer is taken off a septic tank, the rules have not been met. The second is the deadlines: if the agency orders pumping, it must be done within 10 days, and the system must be presented for inspection within 7 days. After a system is sold or rebuilt, the declaration is renewed within a month.
Untreated wastewater must not be discharged into the storm sewer, field drains or land-drainage ditches. In low-lying spots next to ditches, owners of overflowing holding tanks in particular should remember this. The fine for an individual for breaches can be from 2 to 70 penalty units.
Sources: Ādaži Municipal Council Binding Regulations No. 3/2025, in force from 04.03.2025 (points 4–6, 8–12, 13.1, 16, 26), likumi.lv; list of pumping contractors komunalserviss.carnikava.lv; Cabinet Regulation No. 384, point 4.4, likumi.lv. Checked 30 October 2026.
Septic tank pumping in Ādaži: how it works
We drive to Ādaži along the A1. The road is busy in the morning and evening rush hours, so we agree the time in advance. We choose the size of the vacuum tanker to suit the street: in some of the new neighbourhoods the streets are narrow and the driveways are paved, so the tanker stays on the street and we run the hose to the lid.
When pumping, we follow the municipality's 70% requirement: in the septic tank chambers we remove the crust and the sediment, and we empty a holding tank completely. If a plastic tank sits in high groundwater, it is refilled with clean water straight after pumping so that it does not lift. After the job you receive a certificate with the address, date and volume removed, exactly the document you have to keep for two years in Ādaži.
Example: for a family of four without a water meter, the rules assume 4 m³ a month, so an 8 m³ holding tank fills up in about two months, which comes to around six pumpings a year. For a tank like that, a larger tanker that empties everything in one trip works out better value. Pumping up to 6 m³ costs from €90, up to 10 m³ from €110. More detail: holding tank pumping.
You can send a request for septic tank pumping in Ādaži, for BIO plant maintenance (from €160) or for both jobs in one trip.
Terraced houses, apartment projects and commercial sites
Apartment and commercial buildings in Ādaži usually have a connection to the town sewer, so they need different work. Cafés, canteens and shops that prepare food must clean their grease trap regularly (from €90). A building whose sewer lies lower than the street network needs a sewage pump station and its maintenance.
Terraced-house developments sometimes have a shared treatment plant or a shared holding tank for several units. A system like that benefits from one responsible person who orders the pumping and keeps the documents for all the units. On shared systems: treatment plants for a village and pumping for businesses.
Connecting to the mains sewer in Ādaži
We found no municipal co-financing for connections in Ādaži. The former Carnikava Municipality programme was cancelled in 2022, and the water-services regulations No. 72/2022 do not provide for support. The owner builds the connection pipe at their own expense and also pays a one-off fee for the connection capacity.
Connecting is mandatory for new builds if the street already has a network, and for existing houses within a year after a new network in the street is put into service. If a network has just been built in your street, plan the connection pipe and the decommissioning of the old septic tank in good time: pumping, cleaning and backfilling. Building the connection pipe costs from €25/m. Documents and the steps: connecting to the mains sewer.
Nearby places
To the east is Vangaži, to the north along the A1 Saulkrasti, to the south-west Riga and further on Mārupe. All places and their rules: where we work.