Wastewater treatment in sparsely populated areas 

Domestic wastewater must be treated in such a way that the load on the environment is reduced by at least 80 percent for organic matter, at least 70 percent for total phosphorus, and at least 30 percent for total nitrogen, compared to the load of untreated wastewater determined using the load factor of scattered settlements.

If the property is not connected to the sewer network, the waste water must be diverted and treated in such a way that it does not pose a risk of environmental pollution.

Domestic waste water must be treated before it is discharged into the ground, a watercourse or a ditch, an artificial pond or a drain in accordance with Chapter 1, Section 3, Subsection 1, Section 6 of the Water Act. Wastewaters other than water toilets can be discharged untreated into the ground if their quantity is small (carrier water) and they do not pose a risk of environmental pollution.

The owner of the property must ensure that the property has a suitable wastewater treatment system for domestic wastewater treatment. The property's wastewater treatment system must be designed and built and maintained in such a way that the basic cleaning requirement is met.

If the property is located in an area sensitive to pollution, i.e. in a groundwater area suitable for water procurement or no more than 100 meters away from a body of water, the owner of the property must ensure that the waste water treatment system based on the requirements in force before 2004 according to the time of construction or the granted building permit meets the basic cleaning requirement.

In areas other than those sensitive to pollution, the wastewater treatment system as mentioned above must be brought to a condition that meets the basic cleaning requirements when a water toilet is built on the property or repair and alteration work is carried out requiring a permit for water and sewage equipment, where the system is renewed or repaired in its entirety, or a repair requiring a building permit comparable to the construction of a building is carried out. and change work.

The owner of the property must ensure that there is a report on the domestic waste water system for the assessment of the load caused by the waste water on the environment and instructions for the use and maintenance of the system. They must be presented to the supervisory authority upon request. The report must include a description of the property's wastewater treatment solution and an assessment of the load on the environment and the fulfillment of the cleaning requirements, as well as other relevant information about the system. The operating and maintenance instructions must contain the necessary information for the proper use and maintenance of the wastewater system and the wastewater treatment system.

When a new wastewater system is built on the property or the operation of the existing system is enhanced, the property owner must ensure that a plan is drawn up for the domestic wastewater system. In this case, there is no need for a separate report on the domestic wastewater system. The plan for the wastewater system must be attached to the permit application submitted to the building control.

The municipality must also comply with the wastewater treatment environmental protection regulations. They state the following about the treatment of domestic wastewater outside the sewer network:

The following protective distances must be observed when placing domestic waste water soil treatment equipment and the discharge point for treated waste water on the property:

• domestic water well and geothermal well: 20-50 (depending on the slope of the terrain and the soil)
• water body: 20-30 m from the shoreline according to mean water level
• road, plot boundary, neighbor's building: 5 m
• residential building: 5 m
• ditch: 5-10 m from soil treatment equipment
• groundwater: 0,25-0,5 m from the ground filter (protective layer above the highest groundwater level) OR 1-2 m from the ground absorption plant (protective layer above the highest groundwater level)

In pollution-sensitive areas, domestic wastewater must be treated in such a way that the load on the environment is reduced by at least 90 percent for organic matter, at least 85 percent for total phosphorus, and at least 40 percent for total nitrogen, compared to the load of untreated wastewater determined with the help of the scattered population load factor.

Groundwater areas and areas that are less than 200 meters away from a body of water referred to in the Water Act are considered areas sensitive to pollution.

In groundwater areas, the absorption of treated and untreated domestic wastewater into the ground is prohibited, with the exception of treated gray wastewater.

The construction of a water toilet is prohibited if the emptying of precipitation, closed and similar domestic waste water tanks is not possible due to the lack of a road connection or another reason.

Small amounts of washing water, e.g., carry water, can be absorbed 10-20 m from the shoreline. Even a small amount of washing water must not enter the waterway directly.

Wastewater soil treatment systems must always be implemented and placed above the average annual highest water level so that untreated wastewater does not wash directly into the watercourse during a flood.