Registering a decentralised sewage system: what to register and how

Who has to register a system

At national level, this is governed by Cabinet Regulation No. 384 “Regulations Regarding the Management and Registration of Decentralised Sewerage Systems”. It applies to systems within the territories of villages and towns that are not connected to the mains sewer and in which wastewater is collected or treated:

• in factory-made wastewater treatment plants (BIO plants) that discharge the treated water into the environment and have a capacity of less than 5 m³ a day;
• in septic tanks (tanks with two or more chambers, from which the settled water overflows into the environment);
• in holding tanks, in which untreated wastewater and sediment accumulate.

Registering the system is the duty of its owner or possessor. If the property is outside the boundaries of a village or town, the national regulations do not apply to it, but municipal binding regulations set their own scope. In Ropaži Municipality, for example, they apply to the villages and the town. If you're not sure, ask the keeper of the register.

What to include in a septic tank registration application

Each municipality has its own form, but the information requested is similar. Prepare:

• the property address and cadastral number, the owner's name and contact details;
• the number of declared and actual residents, water meter readings or approximate monthly consumption;
• the type of system (septic tank, holding tank or BIO plant) and its volume or model;
• the year it was put into service and how the system is managed: how often it is pumped, when it was last serviced;
• whether you plan to connect to the mains sewer.

Some municipalities also require documents to be attached. In Mārupe Municipality, a BIO plant requires the technical passport, from which it can be established that the plant is installed at the specific address. A septic tank requires the construction diagram of the infiltration system, and a holding tank the construction diagram or other available technical documentation.

How to register: step by step

1. Find out who keeps the register It may be a municipal institution or a water utility. A list for Riga and the largest municipalities in the Riga region is in the table below.
2. Prepare the information You'll find the volume in the technical passport or the building design. If you don't know it, it can be determined during pumping, because the pumping contractor sees how many cubic metres have been pumped out.
3. Fill in the form The form is usually on the website of the municipality or the keeper of the register. National regulations provide that the application can be submitted in person, by post or electronically.
4. Submit it For an application sent electronically, most municipalities require a secure electronic signature or sending it to an official e-address.
5. Get confirmation The keeper of the register sends a notice of registration within a month. Mārupe Municipality issues a registration certificate, which also states the minimum emptying frequency.
6. Report changes If the owner, the type of system, the volume or the number of residents changes, report it within a month at the latest. The owner of a BIO plant submits a copy of the maintenance document to the keeper of the register within a month after each maintenance visit.

Deadlines

National regulations provide that the owner submits the application by the date set by the keeper of the register or within six months after the ownership rights have been registered in the Land Register. Municipal registers had to be set up by 31 December 2021, and by the same date the systems had to meet the requirements of the regulations.

In Riga, systems built by the end of 2021 had to be registered by 31 December 2021, and new ones must be registered within one month of construction or being put into service. In Mārupe Municipality, the system of a new build must be registered before the building is put into service. If you have missed the deadline, register the system as soon as possible. The service is still available now.

If the system had not been put in order by the end of 2021 and there is a mains sewer in the street or road next to the property, the regulations required the property to be connected to it by 31 December 2023. Read more on the page connecting to the mains sewer.

How the requirements differ in Riga and the Riga region

The basic requirements are the same everywhere, but each municipality decides who keeps the register, how often wastewater must be removed and whether anything has to be submitted every year. The main differences:

Read more about each location on our pages about Riga and the Riga region. Regulations change: the new version of Mārupe Municipality's regulations, for example, came into force on 20 October 2026, so check the current version on likumi.lv or the municipality's website before you submit anything.

The register of decentralised sewage systems in Riga

In Riga, registrations and declarations are accepted by the Riga Housing and Environment Department. The service is free of charge, and the application is processed within 30 working days. You can submit it at a Riga Neighbourhood Residents' Centre, by post, or electronically to the official e-address or by e-mail if the document is signed with an electronic signature. If the department does not ask for anything further within a month, the system can be considered registered.

Every year by 1 May, a declaration of the volume of wastewater removed in the previous year must be submitted in Riga. So keep the documents for every pumping. For what they must contain, read contract with a pumping contractor and pumping certificate.

Inspections and fines

The Law on Water Management Services allows municipalities to provide for administrative liability in their binding regulations for breaches of these rules. In Riga and Ķekava Municipality, a private individual may be given a warning or a fine of up to 70 fine units, and in Mārupe Municipality up to 100 units. One fine unit is €5, so that is up to €350 and €500 respectively.

A municipal representative has the right to access the system and to ask for documents on pumping or maintenance. An inspection goes smoothly if the system is registered, the pumping documents have been kept and the BIO plant has a maintenance record.

What it costs to put the system in order

In Riga, registration itself is free of charge; in other municipalities, check this on the register keeper's website. Costs arise if the system has to be put in order before registration: the septic tank or holding tank needs pumping, the BIO plant needs maintenance, or the volume and condition of a plant without documents have to be established.

If the system does not meet the requirements (for example, a septic tank has no infiltration system or a holding tank is not watertight), the solution may be building a drain field or converting a septic tank into a BIO plant.