From April 2027, Stormossen will take care of the emptying of sludge tanks for households and holiday homes. The change takes place in accordance with waste management regulations (only in Finnish and Swedish).

Septic tanks, sealed tanks, and small-scale treatment plants are emptied at least once a year. If necessary, the emptying interval can be more frequent. For septic tanks and small-scale treatment plants, you don’t need to order the emptying yourself. Stormossen will empty the tank on an approximately 12-month cycle based on the most recent emptying. If emptying is needed more frequently, you can order the service from Stormossen.

Sealed tanks can be emptied on a regular, pre-agreed schedule or on demand. Emptying of sealed tanks takes place at least once a year. You should monitor the fill level, for example using an alarm function, so that the emptying order is placed in time.

Emptying can be ordered from Stormossen via our e-services, by email at liete@stormossen.fi, or by phone at 010 320 7676 (Mon–Fri 9 am–3 pm).

As early as spring 2026, Stormossen will need information about your sludge tank so that the emptying service can be handled as smoothly as possible from April 2027.

You will receive a personal letter in April-May 2026 in which we ask for clarification of details about your sludge tank. Please respond to our questions primarily via our e-services. The letter also includes an attached reply form which you can fill in and return by post. You can also respond by email at liete@stormossen.fi or by phone at 010 320 7676 (Mon–Fri 9 am–3 pm).

We need the following information:

• The type of septic tank: septic tank, sealed tank, or small-scale treatment plant
  • If it is a small-scale treatment plant, what brand?
• The size of the tank/container
• The date of the most recent emptying
• The location of the sludge tank on the property, please attach a map/drawing
• Any need for emptying more than once a year

In addition to the details about the sludge tank, we need to know your name, address and phone number, so don’t forget to include them if you send an email.

Stormossen will procure the sludge transport services during the spring 2026. Before the summer, Stormossen’s website will announce which contractors will handle emptying in different areas from April 2027. In practice, you don’t need to know which contractor will empty your septic tank, as Stormossen is responsible for all emptyings. You handle all your matters relating to sludge tank emptying with Stormossen.

If we have your phone number, you will receive a text message a couple of weeks before the first emptying. The text message will notify you of the emptying time on a weekly basis. Unfortunately, we cannot notify you of the exact day and time of the emptying. Emptying schedules and routes will be planned at the beginning of 2027. After that it will also be possible to check the planned emptying via our e-services.

Vaasa Region’s Waste Committee will set the waste management tariff for 2027 during 2026. The current waste management tariff can be found on the Committee’s website (only in Finnish and Swedish).

An interruption in the emptying of sewage sludge requires an application to Vaasa Region’s Waste Committee, which makes a decision on the matter as an exception to waste management regulations (only in Finnish and Swedish). It is not permitted to live or stay on the property during the interruption.

An extended emptying interval for the property’s septic tank emptying requires an application to Vaasa Region’s Waste Committee, which makes a decision on the matter as an exception to waste management regulations.

• Properties with pressurized water but using an outdoor toilet, dry toilet, incineration toilet or similar system, so that only grey water is generated at the property, may extend the emptying interval so that emptying is carried out every 36 months.
• Properties with an incineration toilet that has a separate collection container for urine may apply for an extended emptying interval so that emptying is carried out every 24 months, provided that the collection container is sufficiently large.
• Properties with a water connection but which are used little, at most 3 months per year (e.g. holiday homes), may extend the emptying interval so that emptying is carried out every 24 months.
• Properties with only carried water and which do not compost the sludge may extend the emptying interval so that emptying is carried out every 36 months.

Own treatment of sludge is prohibited under waste management regulations (only in Finnish and Swedish), with the exception of the following situations. Own treatment of wastewater sludge must always be reported in writing to Vaasa Region’s Waste Committee in advance.

Active farmers
Active farmers may spread sludge generated from their own household living in treated form for fertilization purposes on their own fields or fields in their own possession. Sludge must always be lime-stabilized before being spread on fields. Only active farmers can apply for a permit to spread sludge on fields. Read more about the conditions in the waste management regulations (only in Finnish and Swedish).

Properties with carried water
Properties without a water connection may compost the sludge generated on the property in a compost meeting the criteria in § 19. A notification must be made to the waste management authority.

Properties with a water connection
Sludge bags from small-scale treatment plants, material from phosphorus separation tanks, solid sludge from grey water systems, sludge from outdoor toilets, and material from soil and infiltration beds may be composted. Composting is possible if the amount of sludge generated is small and its treatment on the property does not cause danger or harm to the environment or health, and if the environmental protection authority recommends granting a permit. Composting is carried out in accordance with § 19. Only solid sludge may be composted.

Before composting begins, a notification must be made to the waste management authority. Vaasa Region’s Waste Committee may prohibit the own treatment of sludge if the matter has been handled in violation of waste management regulations or the Environmental Protection Act.

A composting permit is not granted for sludge in liquid form. Dry toilet waste must be composted in accordance with § 19 on the property or transported within the property-specific waste collection to a location designated by the Waste Committee.

Wastewater sludge or wastewater from sedimentation tanks, small treatment plants, sealed containers and the like must not be spread in forests or other locations in the terrain.

Composting § 19
Dry toilet waste, pet excrement, and sludge from small treatment plants referred to in § 38 of these regulations may only be composted in a purpose-designed closed and well-ventilated composting container, which is constructed so that pests cannot access it and leachate does not seep into the ground. The composting container must be maintained according to the instructions and kept in proper working order. The composting period for feces-based waste is at least one year. Biowaste and sludge must not be composted in the same compost. Read more about composting in the waste management regulations (only in Finnish and Swedish).

Did you know that Stormossen and Vaasa Region’s Waste Committee have an electronic service which you can use to handle matters relating to your waste management? You can submit your septic tank details to us via our e-services, which makes the emptying process easier.

Here’s how to proceed:

• To log in for the first time you need your customer number and invoice number, which can be found on your Stormossen invoice. After that you can create your own login credentials.
• Select the property for which you are making the wastewater notification. Please note that you need to make separate notifications for each property, including your holiday home.
• Select Make a wastewater notification and answer the questions as thoroughly as possible. Check that the details are correct and submit the notification. Please note that you cannot amend the notification after it has been submitted.
• If you have any questions regarding the completion of the wastewater notification, contact Stormossen by email at liete@stormossen.fi or by phone at 010 320 7676 (Mon–Fri 9 am–3 pm).