Guidelines to Statutory Order on the Licensing of Waste Water Discharges

14. Establishment of holding tanks for waste water - collection, emptying and transportation

14.1 General provisions of the Environmental Protection Act  
14.2 Powers of the local council
14.2.1 Quality requirements for holding tanks
14.2.2 Siting and size of holding tanks
14.2.3 Clearance distance from abstraction plants
14.2.4 Health hazards and nuisance to neighbours
14.2.5 Emptying and disposal
14.3 Powers of regional councils
14.3.1 Delimitation against other legislation
14.3.2 Emptying and disposal
14.4 Aboveground holding tanks
14.4.1 Emptying and disposal
14.5 Establishment and emptying of holding tanks for waste products from alternative toilet systems  
14.6  Waste water stabilisation ponds without an outlet
14.6.1 Powers of local councils
14.6.2 Powers of regional council
14.6.3 Waste water stabilisation ponds with a permeable bottom
14.7 Supervision and enforcement  
14.8  Variation or revocation of licences 
14.9 Right of appeal

14.1 General provisions of the Environmental Protection Act

Part 3, section 19 of the Environmental Protection Act lays down rules governing the licensing of underground tanks for storing any substances, products or materials likely to pollute the groundwater, soil and subsoil. The rules do not apply to licences for tanks for collecting waste water etc. established inside houses and other buildings, which are governed by rules and regulations laid down by the Ministry of Housing and Urban Affairs, including the Building Regulations.

Under section 19(4) of the said Act, licences for underground tanks are issued by the regional council, unless otherwise stipulated by the Minister.

Part 14 of the Statutory Order provides detailed rules on licences for the discharge of waste water into underground holding tanks and to holding tanks in general.

The said rules are contained in section 37 of the Statutory Order, the relevant authority in this respect having been conferred on the local council, subject to certain conditions.

Section 20 of the said Act lays down general provisions pertaining to the revocation or variation of the aforesaid licences.

14.2 Powers of the local council

The local council is empowered to issue licences for the discharge of domestic waste water, including human waste and surface run-off from properties with one or two households, to holding tanks wholly or partly buried in the ground, cf. section 37(1) of the Statutory Order.

'Properties with two households' means, for example, a semi-detached house or a house containing two separate flats.

Separate discharges of domestic waste water

According to the definition of domestic waste water given in section 4(2) of the Statutory Order, the local council is also the licensing authority, for example, in the case of the discharge of black waste water (from water closets) to a holding tank. This may be the case where only the grey waste water (other domestic waste water) is to be discharged by percolation. In this connection it is essential to ensure that any licensing for percolation conforms to Part 12 of the Statutory Order.

Waterless or low-water toilet systems

Licences for the collection, emptying out and transportation of waste from waterless or low-water toilets may be issued by the local council or the regional council depending on the volume and type of waste water concerned, cf. section 14.5 below.

For the final disposal and application of waste from waterless or low-water toilet systems, see Part 13 of these Guidelines.

Holding tank for storm water from roofs

The use of underground holding tanks for roof run-off for toilet flushing and washing of clothes in private households now requires licensing by the local council. In connection with a contemplated amendment of the Statutory Order on water quality and monitoring of water supply, this will be altered so that in future no separate licence will be necessary for the establishment of such tanks. Instead, such tanks and associated installations will be subject to general quality requirements.

14.2.1 Quality requirements for holding tanks

Prior to issuing a licence, the local council must verify that one of the following conditions concerning the quality of the holding tank has been satisfied, cf. section 37(1)(i-iv) of the Statutory Order.

Type approval by PUFO

The type of holding tank must be approved by the Danish Approval Committee for testing oil tanks ("Prøveudvalget for Olietanke" - PUFO) under the Statutory Order on the monitoring of oil storage in force from time to time, cf. section 37(1)(i) of the Statutory Order.

Quality requirements deemed by licensing authority to be fulfilled

The holding tank must be deemed by the licensing authority to fulfil similar quality standards for waste water storage, cf. section 37(1)(ii). These are standards which, under the Statutory Order on the monitoring of oil storage, may be relevant in connection with an assessment of the suitability of a holding tank for storing waste water. Alternatively, certain tanks may have been approved in other countries for storing waste water or may have been approved for collecting roof run-off.

Vacuum systems

If a property has a toilet system whose operation requires the tank to be completely water-tight (vacuum system), the holding tank must satisfy the requirements for approval by the licensing authority for inclusion in such a system, cf. section 37(1)(iii)of the Statutory Order.

Concrete tank built by a qualified sewage contractor

If the holding tank is to be constructed on site as a concrete structure, the work is to be carried out by a qualified sewage contractor, and the design must be approved by the licensing authority prior to the establishment of the structure/holding tank, cf. section 37(1)(iv) of the Statutory Order.

Use of existing tanks as holding tanks

An existing tank which has been used for another purpose may be approved by the licensing authority for use as a holding tank. However, it must be verified and be capable of proof that the quality of the tank is adequate for the purpose of waste water collection. This is consequently a matter of assessment on a case-by-case basis, and the general criterion should be for the tank in question to conform to the quality requirements for new holding tanks.

In respect of concrete tanks built in situ, the licensing authority must assess the quality of the concrete and the tightness of the tank, and must further verify that the tank does not contain any deposited solids. This may be done by inspecting and flushing the tank so as to remove any deposits. The tightness may be checked by visual inspection, e.g. for any cracks in the concrete, or by means of leak testing (the tank is filled with water, and after approx. 24 hours the tank is inspected for leaks).

For tanks made of materials other than concrete, e.g. plastic, fibre glass, etc., the same criteria apply to the assessment of suitability.

Disused liquid manure tanks etc.

Sometimes disused liquid manure tanks may serve as tanks for collecting waste water. In such cases, it is essential for the licensing authority to commission a detailed assessment of the suitability of the tanks to be used, as they may be old and leaky.

Should old oil tanks be reused for the collection of storm water?

The Environmental Protection Agency cannot recommend reusing old oil tanks, for example as storm water tanks, as it is difficult to clean them sufficiently of oil. Tanks will have to be cleaned before use, and the only effective way of cleaning an oil tank is by high-pressure cleaning. Only tanks exceeding 600 litres allow entry for inspection. Smaller tanks must therefore be dug up and cut open, so as to provide access for high-pressure cleaning.

14.2.2 Siting and size of holding tanks

In order for a holding tank to be licensed by the local authority, the tank must be completely or partly buried on the property, cf. section 37(1) and (2) of the Statutory Order, meaning that the holding tank must be referable to the title number(s) of the property in question.

Required clearance distance from roads and boundaries

In addition, under section 37(5) of the Statutory Order, the licensing authority must ensure that the clearance distance of the holding tank from roads and boundaries is not less than 2 metres.

Clearance distance from buildings

In respect of the clearance distance from buildings, see the Building Regulations dated 1 April 1995 and the Building Regulations for detached or semi-detached houses dated 25 June 1998. In the proximity of buildings, the tank is to be sited so as to fulfil the criteria of DS 415 Code of Practice for foundation engineering (buildings).

Siting of holding tank

In addition, under section 37(6) of the Statutory Order, the holding tank is to be sited and installed with easy access for emptying by vacuum tanker. The top cover of the holding tank must be easily accessible. It must be possible for one man to lift the cover, and it must not be concealed either by soil, grass or other materials.

Size of holding tank

The size of the holding tank must be adapted to the waste water intake and the required emptying frequency, cf. section 37(6) of the Statutory Order.

The appropriate size depends on the type of premises (for intermittent or permanent residence), the volume of the waste water intake (including both grey and black waste water or only part of the waste water discharged from the building), the planned emptying frequency and the capacity of the vacuum tanker.

According to the Guidelines for construction of sewage systems published by the Danish Technological Institute (DTI), the tank size for holiday cottages should be 2,500-3,000 litres, and for permanent residences 5,000-6,000 litres.

14.2.3 Clearance distance from abstraction plants

If a holding tank is to be completely or partly buried on a site that includes an abstraction plant for drinking water pursuant to the Act on Water Supply, the licensing authority is to ensure compliance with the clearance distance requirements set out in Table 14.1 prior to issuing the licence, cf. section 37(3) and (4) of the Statutory Order.

14.2.4 Health hazards and nuisance to neighbours

Section 37(7) of the Statutory Order provides that, prior to the issue of a licence for the establishment of a holding tank, precautions are to be taken to prevent any health hazards to humans or animals and any nuisance to neighbours.

14.2.5 Emptying and disposal

Prior to licensing the establishment of a holding tank, the licensing authority must generally provide for the appropriate emptying, transportation and final disposal of waste from holding tanks. This includes documentation of transportation, the issue of a licence for final disposal, including indication of the location for such final disposal, cf. section 37(8) and (9) of the Statutory Order.

Ordinary domestic waste water

As a general rule, ordinary domestic waste water will be transferred to a waste water treatment plant.

The use of any municipal collection scheme covering his property is mandatory on a landowner, cf. section 44 of the Statutory Order.

If a property is not covered by a municipal collection scheme, the local council must ensure, prior to licensing the establishment of the property in question:

That the holding tank will be emptied by vacuum tanker in an appropriate manner, e.g. by contracting with a tank cleaner

That a contract is entered into between the tank cleaner and the local council for the direct tanking of the waste water to the waste water treatment plant as directed by the local council, cf. section 37(8) of the Statutory Order.

The waste water must not necessarily be transported to a waste water treatment plant in the municipality in which the property in question is situated, but may be transferred to a treatment plant in another municipality if a contract to that effect has been entered into between the tank cleaner and the local council.

The mandatory collection scheme does not apply, however, where a licence for reusing the waste water has been issued, cf. section 37(8) of the Statutory Order.

Waterless or low-water toilet systems

Prior to licensing the establishment of a holding tank for human waste, the local council must provide for appropriate emptying, transportation and final disposal of the contents, and it must be documented that a licence for final disposal has been granted, cf. Part 13 of these Guidelines (on the application of waste products to the surface of the ground).

Reference is also made to section 15.2 below in respect of the collection of sludge from holding tanks containing human waste.

Part 15 of the Statutory Order deals with the detailed rules governing collection schemes. For holding tanks for human waste, the rules set out in Part 15 of the Statutory Order do not apply where a licence has been issued for alternative final disposal or reuse, cf. section 44(3) of the Statutory Order.

Surface run-off

In principle, collected surface run-off may be reused according to the general rules set out in Part 13 of these Guidelines.

14.3 Powers of regional councils

When are regional councils competent to issue licences?

Regional councils are generally empowered to license the discharge of waste water into holding tanks completely or partly buried in the ground, cf. section 38(1) of the Statutory Order, except in cases where the local council is empowered to do so under section 37(1) of the Statutory Order.

Examples of licences to be granted by regional councils are for the discharge of domestic waste water, including human waste, from a property with more than two households, the discharge of domestic waste water from two properties sharing a holding tank, the discharge of industrial process waste water and waste water from milking parlours.

In addition, a regional council is empowered to issue a licence when a holding tank is buried elsewhere than on the property occupied by the household(s) using the tank, cf. section 37(2), and when the holding tank does not comply with the clearance distance requirements set out in section 37(3) and (4).

Under section 38(2) of the Statutory Order, any decision by a regional council must, however, comply with the requirements set out in section 37(1) and (5)-(9) of the Statutory Order.

14.3.1 Delimitation against other legislation

Statutory Order on livestock manure

Certain categories of waste water typically to be found on agricultural properties may also be governed by Statutory Order No. 550 of 24 July 1998 issued by the Ministry of Environment and Energy on commercial livestock management, livestock manure, ensilage, etc. The types of waste water concerned are water from milking parlours (water used to clean milking systems), water used to wash farm products etc., water used to clean feeding equipment and water used to clean poultry houses.

These types of waste water may be transferred to liquid manure tanks or separate tanks, and are therefore also governed by the rules on storage, emptying and disposal set out in the Statutory Order on livestock manure.

14.3.2 Emptying and disposal

Domestic waste water etc.

For emptying of holding tanks used for domestic waste water, human waste and surface run-off, see section 37(8) and (9) and section 14.2.5 of these Guidelines.

Other waste water, including industrial process waste water

For emptying and disposal of the contents of holding tanks used for storing other types of waste water, including industrial process waste water etc., see section 38(3) of the Statutory Order and section 14.3.2 of these Guidelines.

This means that the regional council is to provide for appropriate emptying, transportation and final disposal of the contents of the tanks, and the applicant is required to document that a licence for final disposal has been obtained.

Discharge of waste water to the ground surface

Thus, in the case of waste water to be sprayed on the surface of the ground, the applicant must indicate the site of application. On the basis of this information, the regional council must verify that the holding tank is emptied and the contents finally disposed of in a manner approved by the regional council.

14.4 Aboveground holding tanks

Waste water etc.

Aboveground holding tanks for waste water, including human waste, are subject to the same rules and regulations as underground tanks, except for the provisions of section 37(2)-(4) of the Statutory Order on the siting of holding tanks on a landowner's own property and clearance distance requirements for siting near water abstraction plants, section 39 of the Statutory Order.

Storm water tanks

The establishment of aboveground holding tanks for surface run-off is not subject to licensing, but must be notified to the local council no later than three weeks in advance, cf. section 39(2) of the Statutory Order.

14.4.1 Emptying and disposal

The rules on emptying and disposal apply correspondingly to waste water from the holding tanks referred to in section 39 of the Statutory Order, cf. section 37(6)-(9) of the Statutory Order and Chap. 15 below.

14.5 Establishment and emptying of holding tanks for waste products from alternative toilet systems

The establishment and emptying of four different alternative types of waterless or low-water toilet are covered and described under these Guidelines.

	Composting toilets/Humus toilets
	Composting/Humus toilets with urine separation
	Water flushing toilets with urine separation
	Vacuum toilets

For a detailed description, see section 13.2.2 above.

Licences for the establishment of holding tanks for the four types of toilet system mentioned above are issued under sections 37-39 of the Statutory Order. This does not include licences for tanks established inside houses or other buildings, such tanks being governed by the rules and regulations laid down by the Ministry of Housing and Urban Affairs.

However, when licensing the establishment of holding tanks for these types of toilet system, the licensing authority must provide for appropriate emptying and final disposal facilities, cf. section 37(8)-(9) and sections 38-39.

Basically, waste products from such toilet systems are considered comparable to night soil. The local council licenses their collection and disposal, cf. Statutory Order No. 366 of 10 May 1992 on non-commercial livestock management, unsanitary conditions, etc. As a general rule, night soil is to be transferred to a waste water treatment plant.

Licences to apply waste products to the surface of the ground are dealt with in section 13.2.2.

Certain parts of the waste products collected from waterless or low-water toilet systems are generally to be handled according to the rules on ordinary waste water. This applies to:

	Tanks for collecting "carrying water" from toilet systems in which faecal matter is flushed down with water (which is then considered comparable to black waste water)
	Tanks for collecting black waste water (vacuum toilets, faecal matter collected from water flushing toilets with urine separation)

The collection and disposal of waste water from such tanks is subject to Part 14 of the Statutory Order, unless the waste products have been subjected to further treatment, cf. Part 13 of the Statutory Order.

14.6 Waste water stabilisation ponds without an outlet

Basically, no-outlet waste water stabilisation ponds for the treatment of waste water are sealed ponds planted with shrubs or trees, such as willows. The pond has no outlet, i.e. neither a drain nor means for percolation. The waste water is absorbed by the plants or evaporates. The dimensions of the pond must allow the storage of the waste water during periods when waste water cannot be absorbed by the plants. Accordingly, a willow pond requires a substantially larger area and volume than a reed-bed plant. On the other hand, it may be used in areas where a reed-bed plant does not provide sufficient treatment, and in areas where waste water cannot be discharged after treatment.

14.6.1 Powers of local councils

The local council may license the discharge of domestic waste water to no-outlet waste water stabilisation ponds for the treatment of waste water from a single property with one or two households, according to section 40 of the Statutory Order.

Prior to issuing such licence, the local council must verify that the waste water stabilisation pond:

	Has watertight bottom and sides
	Is overflow-proof
	Poses no health risk to humans or animals
	Creates no nuisance to neighbours
	Complies with the prescribed clearance distance from water abstraction plants, cf. section 37(3)-(4).

For the purpose of the specification by the local council of requirements for the pond to be watertight, see the Danish EPA’s Guidelines No. 1 on the establishment of reed-bed plants and No. 3 on biological sand filter systems up to 30 p.e., both published in 1999.

The local council is generally responsible for verifying that the pond is appropriately designed and has the required capacity to prevent overload and overflow. The local council should therefore make allowance for any changes in the inflowing load, e.g. in connection with change of ownership.

Under section 40(2)(iii), the local council is to verify that the pond poses neither health risks to humans or animals, nor nuisance to neighbours, e.g. due to obnoxious smells. The council should also safeguard against any potential hygiene or health hazards caused by direct or indirect contact with waste water from the pond, and the need to provide protective screening should be assessed.

14.6.2 Powers of regional council

The regional council is competent to license discharges of waste water to no-outlet stabilisation ponds for the treatment of waste water in cases where a licence cannot be issued by the local council. The requirements set out in section 40(2) of the Statutory Order must generally be observed, but section 41(2) empowers the regional council to derogate from the prescribed clearance distance from water abstraction plants, cf. section 40(2)(v).

The regional council is to verify that the stabilisation pond:

	Has watertight bottom and sides
	Is overflow-proof
	Poses no health risk to humans or animals
	Creates no nuisance to neighbours
	Is located at an appropriate clearance distance from water abstraction plant.

14.6.3 Waste water stabilisation ponds with a permeable bottom

Waste water stabilisation ponds with permeable bottom and sides must be considered comparable to an infiltration plant. Typically, the regional council will have the power to license such stabilisation ponds under section 30 of the Statutory Order, the local council being competent to license the disposal of domestic waste water by percolation under section 29 of the Statutory Order only if the pond concerned includes seepage drains.

14.7 Supervision and enforcement

Supervision

It is the responsibility of the local council to supervise holding tanks and no-outlet waste water stabilisation ponds operated by private owners, regional or central government bodies, cf. section 57(1) of the Statutory Order and section 65 of the Environmental Protection Act. The local council is responsible for monitoring compliance with such licences.

Moreover, the local council is responsible for monitoring compliance with any enforcement or prohibition notices issued under statutory provisions.

The regional council supervises public holding tanks and no-outlet waste water stabilisation ponds, cf. section 57(2) of the Statutory Order.

Enforcement

If a violation of any local council decision under sections 37, 39 or 40 of the Statutory Order is ascertained by the local council, the local council must take enforcement action against such unlawful conduct under Part 8 of the Environmental Protection Act.

However, as the licensing authority, the regional council is competent to take enforcement action against any non-compliance with decisions under sections 37-41 of the Statutory Order in the case of public holding tanks and no-outlet waste water stabilisation ponds.

If the local council ascertains that a decision by the regional council under sections 38, 39 or 41 of the Statutory Order has been violated, the local council is to refer the matter to the regional council, cf. section 65(4) of the Environmental Protection Act, which will subsequently decide upon the matter in accordance with the provisions of the said Act.

14.8 Variation or revocation of licences

Licences issued subject to sections 37-41 of the Statutory Order may be revoked or varied at any time without compensation by the licensing authority, i.e. either the local or the regional council, cf. section 20 of the Environmental Protection Act.

Protection of water abstraction plants

This may be required, for example, in order to protect water supply/water abstraction plants from pollution. A damaged/leaking underground holding tank may be a potential source of pollution of water abstraction plants, even where the holding tank conforms to the requirements set out in section 37(3) and (4) of the Statutory Order.

Environmental protection in general

Similarly, it may be required for the purpose of environmental protection in general to revoke or vary a licence. This may be the case, for example, where the holding tank causes overflow, pollution of surface water or unacceptably unsanitary conditions due to leaks, inappropriate emptying, disposal, etc.

Revised waste water planIn connection with the implementation of a different method of waste water discharge in accordance with a revised waste water plan, the local council is competent in any case to revoke the licence if this is required for the purpose of implementing a waste water plan. In these cases, revocation of the licence is deemed to become effective upon the commissioning of the new system, cf. section 20(4) of the Environmental Protection Act, and the decision by the local council cannot be brought before another administrative authority.

Other decisions under section 20 of the Environmental Protection Act may be brought before the Environmental Protection Agency under section 91 of the Environmental Protection Act.

14.9 Right of appeal

Local council decisions

Decisions by the local council under sections 37, 39(1) and 40 of the Statutory Order cannot be brought before any other administrative authority, cf. section 43 of the Order.

Regional council decisions

Decisions by the regional council under sections 38, 39(1) and 41 may be brought before the Environmental Protection Agency in accordance with the general provision to that effect laid down in section 91 of the Environmental Protection Act.

Danish-EPA decisions

Decisions made by the Environmental Protection Agency in appeals against licences issued by a regional council under sections 38, 39 and 41 cannot be brought before the Environmental Appeal Board, cf. section 103 of the Environmental Protection Act.