Section 4 The processing and management of construction site water on temporary construction sites
Construction site water refers to water or sludge generated on construction sites, such as lower and/or upper groundwater seeping into the construction building pits, rainwater, drainage water from areas surrounding pits, water used for various work processes such as drilling as well as water or sludge generated during the renovation of external building surfaces, which must then be conveyed away from the site in order to continue construction.
Construction site water generated by construction and renovation sites and other temporary operations containing an amount of harmful substances that causes a risk of pollution must not be directed into the sea, a water body specified in the Water Act (587/2011), the sewer network or open ditches without pre-processing that either removes the harmful substances or sufficiently decreases the amount of harmful substances in the water. The absorption of water into the ground requires that the construction site water will not pollute the groundwater. The water directed into the drainage water system must not cause any blockages or corrosion in the sewer network.
If construction site water is going to be directed into the drainage, waste or combined sewer system, you must contact the Helsinki Region Environmental Services Authority (HSY). HSY may set requirements for the quality and quantity of the water being directed into the waste water and combined sewer system.
Section 5 Wastewater treatment in areas not connected to a sewer network of a water management authority
The absorption of untreated toilet wastewater into the ground is prohibited. The absorption of untreated toilet wastewater and other domestic wastewater into the ground is prohibited in important groundwater areas.
Building flush toilets in holiday homes on waterfront areas and in the archipelago is prohibited, unless the property is connected to the water supply and sewer system.
The archipelago refers to islands with no permanent road access.
Section 6 The placement and maintenance of domestic wastewater treatment equipment and toilets
The treatment system for domestic wastewater and the point of discharge for treated domestic wastewater on properties must be located at a safe distance from water bodies, domestic wells, ditches or similar channels as well as the border of the property. The sufficient distance is determined case-specifically. The minimum safety distance to water bodies is usually at least 25 metres.
The absorption piping in the absorption area must be located at least one metre above the topmost groundwater level, if possible. The lower surface of the absorption area must be located at least 50 centimetres above the topmost groundwater level, if possible.
The possessor of the property must ensure that the domestic wastewater treatment equipment is functional in all conditions and that its efficiency corresponds to the requirements specified in the Government Decree on treating domestic wastewater in areas not connected to the sewer system (157/2017). Settling wells and sewage tanks must be emptied frequently enough. Sewage tanks must be equipped with an overfill alarm. The emptying of settling wells and closed sewage tanks must comply with the waste management regulations of the Helsinki Metropolitan Area and Kirkkonummi.
Property owners must be knowledgeable about the structure, condition and maintenance of their systems as well as the emptying of the tanks. Owners must keep a record of any maintenance performed on the equipment and the emptying of tanks, which must be presented to the City of Helsinki’s environmental protection authority upon request. The possessor of the property must order the emptying of their septic and sewage tank sludge from the Helsinki Region Environmental Services Authority (HSY) in accordance with the common waste management regulations of the Helsinki Metropolitan Area and Kirkkonummi. Receipts of these transactions must be kept in the property’s maintenance records for three years.
The wastewater treatment system that discharges the treated water into a ditch or absorption pit, for example, must be designed so that representative samples may be taken from the water exiting and entering it in order to ensure efficient treatment.
The bottom sections of composting and dry toilets must be impermeable, and the toilets must be maintained so that they do not cause pollution in the groundwater or other hazards to the environment or health.
Section 7 Placement of outside paddocks and horseback-riding fields and manure removal
In order to prevent water pollution, outside paddocks and horseback-riding fields must be located at a sufficient distance from water bodies and main ditches as well as wells and springs used for acquiring domestic water. Outside paddocks or pastures must not be located in flood risk areas. Outside paddocks refers to open yards with no plant cover for the year-round use of horses and ponies.
The locations of new outside paddocks and horseback-riding fields must comply with the following minimum safety distances depending on the conditions on the plot and its immediate vicinity:
- distance to domestic water well or spring 30–100 metres - distance to water body 20–50 metres - distance to main ditch 10–30 metres
Manure must be removed from outside paddocks and horseback-riding fields daily and placed into a watertight manure storage area. The topsoil of outside paddocks and horseback-riding fields must be replaced when necessary.
A written agreement or receipt must be available for the assignment of manure, which must be presented to the City of Helsinki’s environmental protection authority upon request.
Establishing a stable or expanding the operations significantly must be reported to the City of Helsinki’s environmental protection authority in advance for the purposes of gaining the necessary information for monitoring.
Section 8 The washing and maintenance of vehicles, machines and similar equipment
The professional and other frequent washing of vehicles, machines and similar equipment, or washing using detergents containing hydrocarbon solvents is only allowed in locations where the water can be directed to or collected in the sewage drain through oil and sand separators. Professional washing operations may only utilise approved detergent combinations.
When washing vehicles, machines and similar equipment occasionally using detergents that do not contain hydrocarbon solvents, the water may be absorbed into the ground with permission from the land-owner, provided that it does not cause environmental pollution. Water containing detergents or other agents causing a pollution risk must not be directed to drainage water sewers or open ditches.
Solids and untreated wastewater generated by the washing of vehicles, machines and similar equipment or transfer plates must not be allowed to seep into the sea, water bodies specified in the Water Act or open ditches. Solids and untreated wastewater generated by washing must not be allowed to seep into public areas.
You must not wash or service machinery on work sites located in important groundwater areas.
Section 9 The washing and maintenance of boats
Washing boats with detergents containing hydrocarbon solvents is only allowed on sites where the washing water is directed into sewage drains through oil separators.
Washing boats with detergents that do not contain hydrocarbon solvents is allowed in winter storage areas if the wastewater is absorbed into the ground sufficiently far from the shoreline with permission from the land-owner.
The wastewater from occasional washing of boats using only water may be allowed to seep into the sea.
The primer on the bottom of boats must be removed over a sealed area that prevents environmentally hazardous primer waste from entering the soil and that allows for careful collection and disposal of any primer residue. Paint waste must be disposed of in the manner required for the nature of the waste in question. You must prevent the dust generated by grinding boats from spreading into the environment.
Section 10 Snow dump areas
Snow dump areas must be located and implemented so that the melt water or the waste within the snow do not pollute or cause a risk of pollution. It is prohibited to establish a public snow dump area in an important groundwater area. The prohibition does not apply to establishing local snow dump areas whose use does not involve truck traffic and on which the snow is allowed to melt, or to the establishing of temporary intermediate snow storage areas.
You must give written notice of establishing and opening a public snow dump area to the City of Helsinki’s environmental protection authority well in advance of starting the operation. The notification must contain information on the location of the site, the start date of operations, traffic arrangements, daily operating hours, the amount of snow the site is intended for, any snow processing methods, the manner of disposing of melt water and after-treatment measures. This duty to notify does not apply to the establishment of local snow dump areas or temporary intermediate storage areas as mentioned above.
The operation of the snow dump area or the related traffic may not cause unreasonable disturbance to residential or accommodation premises or care institutions. The use of snow dump areas in the night-time is subject to what has been decreed in section 22 of these regulations on disturbing noise and vibration at night-time.
The use of snow dump areas is prohibited during night-time between 10 p.m. and 7 a.m., if the use or related traffic causes unreasonable disturbance to residential or accommodation premises or care institutions.
The possessor of the snow dump area must ensure that the area is cleaned without delay after the snow has melted.