material approach and shall be declared as one of the following classes, according to EN 13501-1: a Class A1, without the need for testing CWT, when meeting the requirements, specified i
Dimensions
Inlets, outlets and connections
Minimum size of nominal diameter of inlet and outlet according to the nominal capacity of equipment is:
For design of outlet devices, see some examples in Annex C (informative).
Ventilation
Adequate ventilation of the septic tank and the inlet pipework shall be provided to prevent the accumulation of fermentation gases.
Design Basis
When designing wastewater systems, it is essential to specify various criteria based on the intended use Key considerations include the population load, minimum sizing requirements that encompass sludge storage capacity, and additional design parameters for domestic wastewater generated by establishments like hotels, restaurants, and commercial properties.
Load bearing capacity
The mechanical characteristics of tank materials, essential for calculating load-bearing capacity, must adhere to the test methods and values specified in EN 12566-3:2016, Annex D.
The septic tank shall resist the loads resulting from handling, installation and use including desludging and maintenance, for their design life
When tested according to 5.1, the load bearing capacity of the septic tank is declared as:
— maximum allowed height of backfill (in meters);
Septic tanks can be installed in both wet and dry sites, denoted as WET, which indicates the maximum height of the water table measured from the base of the septic tank, or DRY.
Watertightness
General
The septic tank shall meet at least one of the requirements given in 4.3.2 to 4.3.4 when tested according to the methods described in Annex A.
Water test
According to section A.3, septic tank water loss must be assessed after 30 minutes For concrete tanks, the allowable water loss is ≤ 0.1 l/m² of the internal wet surface of the external walls, while tanks made from plastic or other materials should exhibit no leakage.
Vacuum test
When tested according to A.3, the septic tank shall be deemed watertight when the vacuum pressure selected for the test does not deviate by more than 10 % of the selected pressure.
Pneumatic pressure test
The septic tank is considered to be watertight when:
— tested in the conditions given in A.3.4.2 a), the pneumatic pressure selected for the test does not deviate by more than 0,5 kPa (0,005 bar) during the related test period; or
— tested in the conditions given in A.3.4.2 b), the variation of the initial pneumatic pressure (equal to 0,3 bar) is less than 3 kPa (0,03 bar) during 180 s.
Hydraulic efficiency
The extent to which the septic tank retains settling and floating solids, is determined by the hydraulic efficiency of the septic tank according to Clause 5.
Design
The inlet and outlet pipes shall be arranged to ensure that no surcharging or back-flow in the inlet pipe occurs at maximum flow rate.
Access
Septic tanks must be securely covered to prevent unauthorized access and maintain operational safety The design should include access points for routine maintenance, sampling, sludge removal, and cleaning.
Extension shafts and access covers shall be fit for purpose
An opening with a dimension (i.e width for rectangular section or diameter for circular section) of a minimum 400 mm shall be required For an open unit, access is not required
NOTE 1 For installation purposes of open units, there may be local regulations for maintenance access
Access requirements for septic tanks may vary based on applicable regulations in the member state and the intended end use conditions For instance, EN 476 specifies that the minimum opening dimension for a person's access must be 600 mm.
The access dimensions must be clearly stated, and their assessment should be conducted with a measurement accuracy of 0.5% This includes evaluating the mass of individual covers, the securing features, and any locking accessories.
Where a locking accessory or securing feature is used, it shall be designed so that the cover cannot be easily opened with objects readily accessible by children.
Durability
Septic tanks must be made from materials that are physically durable and resistant to corrosion, ensuring their suitability for wastewater environments Additionally, their design should align with the specific service requirements of their intended use.
Carbon steel septic tanks shall have a suitable coating to prevent corrosion.
Reaction to fire
General
Septic tanks must comply with national fire reaction regulations, and their fire performance is categorized based on material properties According to EN 13501-1, septic tanks can be classified as Class A1 without testing if they meet specific requirements, or they can be classified based on test results of the materials used, as outlined in the relevant standards.
NOTE In most cases Class E is considered to be sufficient as a minimum regulatory requirement for the reaction to fire performance of units used in buried (i.e underground) applications
In cases where a unit is not governed by national fire reaction regulations, it may be classified as either a specific class based on criteria a) or b), or labeled as "No Performance Determined" (NPD).
Septic tank classified as Class A1 without the need for testing
The fire performance classification of a septic tank can be designated as Class A1 without testing, as long as each material used in its construction contains no more than a specified amount of combustible content.
1 % of homogeneously distributed organic material, by mass or volume (whichever is the most onerous); and
Precast reinforced concrete and steel used in septic tanks may contain organic materials and additives, but these are present at levels below 1% Due to their low combustibility and specific conditions, both materials can be classified as class A1 for fire performance without the need for testing.
1) See Decision of the Commission 96/603/EC of 1996-10-04 (see OJEU L 267 of 1996-10-19), as twice amended by b) any external coating, if applied over the surface area of the tank, is made on inorganic material(s), which is/are also classified as Class A1.
Septic tank classified according to the test results
To assess the fire performance of a septic tank, all materials used, including any surface coatings, must be classified according to EN 13501-1 The declared fire class will be the lowest classification among these materials The classification for each material is determined through specific test methods outlined in the standards referenced in EN 13501-1.
The constituent materials of a septic tank play a crucial role in its fire performance As defined in EN 13501-1, these materials can significantly influence the unit's reaction to fire.
— homogeneous unit: its material; or
A non-homogeneous unit is defined by its substantial component, which is a material that forms a significant part of the unit Specifically, a layer qualifies as a substantial component if it has a mass per unit area of at least 1.0 kg/m² or a thickness of at least 1.0 mm.
Septic tanks are typically constructed from materials such as unplasticized polyvinylchloride (PVC-U), polyethylene (PE), glass reinforced polyester (GRP-UP), polypropylene (PP), and polydicyclopentadiene (PDCPD) Additionally, they may be made from flexible sheets like PEHD, PP, PVC, or EPDM, with or without surface coatings.
Test specimens used for the test methods, applicable for this classification, shall be prepared according to EN 13501-1 and to the relevant standards referred therein.
Dangerous substances
National regulations on dangerous substances may require verification and declaration on release, and sometimes content, when construction products covered by this standard are placed on those markets
In the absence of European harmonized test methods, verification and declaration on release/content should be done taking into account national provisions in the place of use
An informative database that includes European and national regulations regarding dangerous substances is accessible on the Construction website of EUROPA.
5 Testing, assessment and sampling methods
Load bearing capacity
General
The mechanical characteristics of septic tank materials must be tested and evaluated according to EN 12566-3:2016, Annex D, to ensure accurate calculations of the septic tank's load-bearing capacity.
For buried installation, the load bearing capacity of the septic tank shall be established:
— either by calculation with the knowledge of basic data for material and loads (see 5.1.2);
— or by test directly on the tank of the unit (see 5.1.3)
When a septic tank features a watertight extension shaft or is installed in a water table, it is essential to consider the relevant loads at the maximum installed depth Appropriate tests or calculations must be conducted to verify the load-bearing capacity of the unit.
The load bearing capacity of the septic tanks that are intended to be used only in non-buried conditions shall be assessed only by calculation
For a unit with the container made of flexible sheets, the pit test only shall be used.
Load bearing capacity determined by calculation
One of the following two methods may apply:
— Method 1: Indirect method usable for all materials by declaring the following parameters:
— geometrical data of the septic tank: e.g wall thickness, distance of ribs, shape;
— properties of the materials and components: All parameters given in chapter durability (see 4.5 and Annex D of EN 12566-3:2016)
The manufacturer shall provide in the installation instructions the height of backfill and the maximum height of water table for installation
— Method 2: Directly declaring the performance using the applicable Eurocode:
— Eurocode 2 (EN 1992-1-1) for concrete (where applicable);
— Eurocode 3 (EN 1993-1-1) for steel (where applicable)
The manufacturer must deliver calculation results in accordance with the relevant Eurocode, detailing the height of the backfill and the feasibility of installing the septic tank in either wet or dry conditions, along with the water table height measured from the base of the septic tank.
When Method 1 is employed for assessing load-bearing capacity, the notified body verifies the product's dimensions and material properties In contrast, when Method 2 is utilized, the notified body validates the input data for calculations, reviews the calculations, and confirms the results of the Initial Type Test (ITT) report.
Calculation of backfill loads shall be carried out according to EN 12566-3:2016, 5.1.2.2
A vertical and a horizontal component of the hydrostatic loads shall be calculated according to EN 12566-3:2016, 5.1.2.3
When calculating pedestrian loads, a value of 2.5 kN/m² should be used only if the backfill height (h) is 1 meter or less For heights exceeding 1 meter, pedestrian loads can be disregarded in calculations, as they are considered negligible compared to other loads.
Load bearing capacity determined by testing
The load bearing capacity of the septic tank shall be established by the crushing resistance or maximum load deformation according to EN 12566-3:2016, Annex D
The test results shall ensure that the load bearing capacity under the declared height of backfill is ensured
According to D.5 of EN 12566-3:2016, the septic tank must be installed following the manufacturer's guidelines regarding the maximum allowable backfill height and the suitability for installation in either wet or dry conditions.
— D.2.1 and D.2.2 of EN 12566-3:2016 (crushing resistance test), the height of backfill shall be the minimum of H 1 or H 2 calculated according to Table 1;
— D.4 of EN 12566-3:2016 (vacuum test), the height of backfill shall be the minimum of H 1 or H 2 calculated according to Table 2
Table 1 — Formulae for height of backfill calculation after crushing resistance test
F is the crushing load (kN);
S 1 is the horizontal surface of the septic tank (m 2 );
H W is the height of the groundwater table measured from the bottom of the septic tank (m);
H 1 is the height of backfill (m)
F is the crushing load (kN);
S 2 is the lateral surface of the septic tank (m 2 );
H W is the height of the groundwater table measured from the bottom of the septic tank (m);
H p is the height from the bottom to the top of the septic tank (m) (extension shaft excluded);
H 2 is the height of backfill (m)
Table 2 — Formulae for height of backfill calculation after vacuum test
P is the underpressure (kPa) (see
EN 12566-3:2016, D.4); f is the coefficient (see
H W is the height of the groundwater table measured from the bottom of the septic tank (m);
H 1 is the height of backfill (m) w p
P is the underpressure (kPa) (see
EN 12566-3:2016,D.4); f is the coefficient (see
H W is the height of the groundwater table measured from the bottom of the septic tank (m);
H p is the total height of the septic tank (m);
H 2 is the height of backfill (m)
For open prefabricated tertiary treatment unit, the pit test shall only be used (see example in Figure 3)
Figure 3 — Pit test for open unit
Watertightness
For the declaration of watertightness, the septic tank shall be tested according to the methods described in Annex A.
Hydraulic efficiency
Hydraulic efficiency shall be tested according to methods described in Annex B (normative)
Septic tanks, which have already undergone testing according to methods that comply with Annex B do not need to be tested again
6 Assessment and verification of constancy of performance – AVCP
General
The compliance of the septic tank with the requirements of this standard and with the performances declared by the manufacturer in the DoP shall be demonstrated by:
— determination of the product type;
— factory production control by the manufacturer, including product assessment
The manufacturer shall always retain the overall control and shall have the necessary means to take responsibility for the conformity of the product with its declared performance(s).
Type testing
General
All performance characteristics outlined in this standard must be assessed when the manufacturer chooses to declare these performances, unless the standard allows for declarations based on existing data or accepted performance methods without the need for testing.
Previous assessments conducted in line with this standard may be considered if they utilized the same or a more stringent testing method, followed the same AVCP system, and pertained to the same product or products with similar design, construction, and functionality, ensuring the results are relevant to the product in question.
NOTE 1 Same AVCP system means testing by an independent third party, and for reaction to fire under the responsibility of a notified product certification body (only for products covered by system 1+ and 1)
For assessment purposes, products from the same manufacturer can be categorized into families, where the characteristics of one product are deemed representative of those same characteristics across all products within that family.
NOTE 2 Products may be grouped in different families for different characteristics
Reference to the assessment method standards should be made to allow the selection of a suitable representative sample
In addition, the determination of the product type shall be performed for all characteristics included in the standard for which the manufacturer declares the performance:
— at the beginning of the production of a new or modified septic tank (unless a member of the same product family); or
— at the beginning of a new or modified method of production (where this may affect the declared properties);
Changes in septic tank design, raw materials, component suppliers, or production methods must be reflected in the relevant characteristics, particularly when these alterations significantly impact one or more of the product's features.
Where components are used whose characteristics have already been determined, by the component
Products with regulatory markings that comply with relevant European specifications are assumed to meet the performance claims stated in the Declaration of Performance (DoP) However, this assumption does not absolve the septic tank manufacturer from the responsibility of ensuring that the entire septic tank is properly manufactured and that its components meet the declared performance values.
Test samples, testing and compliance criteria
The number of samples of septic tank to be tested/assessed shall be in accordance with Table 3
Table 3 — Number of samples to be tested and compliance criteria
Characteristic Requirement Assessment method Number of tests/ samples Compliance criteria
Inlets, outlets, internal pipework and connections 4.1.1 According to 4.1.1 Each unit in the product family Characteristic dimensions
Overall dimensions 4.1.2 and 4.1.3 According to 4.1.2 and 4.1.3 Each unit in the product family Characteristic overall dimensions Structural behaviour 4.2 According to 5.1 One unit of the product family — backfill load;
Watertightness 4.3 According to 5.2 and Annex A Each unit in the product family “Pass” or “Fail”
Hydraulic efficiency 4.4 According to 5.3 and Annex B One unit of the product family Grams of beads collected
Access 4.6 According to 4.6 Each unit in the product family Characteristic dimensions
Durability 4.7 According to 4.7 Each material(s) “Pass” or “Fail” according to material used and test method applied
Reaction to fire 4.8 According to 4.8 Each material(s) Declared class A1
(CWT) Declared class: the lowest class according to
EN 13501–1 of the relevant material Release of dangerous substances 4.9 According to 4.9 Each material(s) As relevant
Test reports
Test reports documenting the determination of the product type must be retained by the manufacturer for a minimum of 10 years following the last production date of the associated septic tank.
Shared other party results
A manufacturer can utilize product type determination results obtained from another source, such as another manufacturer or a product developer, to support their own performance declaration for a product that shares the same design, dimensions, raw materials, constituents, and manufacturing methods, as long as certain conditions are met.
— the results are known to be valid for products with the same essential characteristics relevant for the product performance;
To ensure the product meets specific essential characteristics, the party responsible for determining the product type must provide the manufacturer with the test results and report This includes information about the production facilities and the production control process, which are relevant for the Factory Production Control (FPC).
— the manufacturer using other party results accepts to remain responsible for the product having the declared performances and he also:
The product must maintain the same performance characteristics as the one evaluated for product type determination, ensuring no significant differences in production facilities or the production control process compared to the original product.
A copy of the product type determination report must be maintained, which includes essential information for verifying that the product is manufactured in accordance with the same design, using identical raw materials, components, and manufacturing methods.
Cascading determination of the product type results
Certain construction products are provided by companies known as "system houses," which supply some or all components to an assembler The assembler then manufactures the finished product in their factory based on an agreement.
A system house, legally established for manufacturing or assembling products, can assume responsibility for defining the product type based on key characteristics of an end product This end product is then manufactured or assembled by other companies in their own facilities.
The system house must provide an "assembled product" made from its own or externally sourced components for product type determination, and subsequently share the product type report with the assemblers, who are the actual manufacturers responsible for the product in the market.
In addressing this situation, the cascading determination of product type should be included in the technical specifications, particularly for characteristics that involve a notified product certification body or a notified test laboratory.
The product type report obtained by the system house from a notified body can be utilized for regulatory marking by assemblers without needing to engage the notified body again for the determination of essential characteristics that have already been tested, as long as certain conditions are met.
2) The formulation of such an agreement can be done by licence, contract, or any other type of written consent
The assembler produces a product using the same combination of components and assembly methods as specified in the product type report obtained by the system house If the report is based on a component combination that does not accurately represent the final market-ready product, or if the assembly deviates from the system house's instructions, the assembler must submit the finished product for a new product type determination.
— the system house has notified to the manufacturer the instructions for manufacturing/assembling the product and installation guidance;
The manufacturer is responsible for ensuring the product is assembled correctly, following the provided manufacturing and assembly instructions, as well as the installation guidance communicated by the system house.
The manufacturing and assembly instructions, along with installation guidance provided by the system house, are essential components of the assembler's Factory Production Control system and play a crucial role in the formulation of the product type report.
The assembler must maintain documented evidence that the combination of components and manufacturing methods used align with the product type report obtained by the system house It is essential for the assembler to keep a copy of this report for reference.
The assembler is responsible for ensuring that the product meets the declared performance standards, including its design and manufacturing, regardless of any agreements with the system house regarding liability This responsibility is affirmed when the assembler affixes the regulatory marking to the product.
Factory production control
General
The manufacturer shall establish, document and maintain an FPC system to ensure that the products placed on the market comply with the declared performance of the essential characteristics
The FPC system will include established procedures, routine inspections, and assessments to effectively manage and control raw materials, components, equipment, the production process, and the final product.
All the elements, requirements and provisions adopted by the manufacturer shall be documented in a systematic manner in the form of written policies and procedures
This factory production control system documentation aims to establish a shared understanding of performance evaluation, ensuring that the required product standards are met It facilitates the effective operation of the production control system, allowing for thorough checks on product performance Ultimately, factory production control integrates operational techniques and measures to maintain and verify that products comply with the declared essential characteristics.
In case the manufacturer has used shared or cascading product type results, the FPC shall also include the appropriate documentation as foreseen in 6.2.4 and 6.2.5.
Requirements
The manufacturer must ensure the effective implementation of the FPC system according to the product standard It is essential to document the tasks and responsibilities within the production control organization and maintain this documentation regularly.
The roles and responsibilities of personnel involved in managing, executing, or verifying work that impacts product consistency must be clearly defined This is especially crucial for those tasked with initiating preventive measures against product inconsistencies, addressing issues when they arise, and identifying and documenting problems related to product consistency.
Personnel involved in tasks that impact product performance must possess the necessary education, training, skills, and experience It is essential to maintain records to verify their competence.
In each factory the manufacturer may delegate the action to a person having the necessary authority to:
— identify procedures to demonstrate constancy of performance of the product at appropriate stages;
— identify and record any instance of non-constancy;
— identify procedures to correct instances of non-constancy
The manufacturer must create and maintain up-to-date documentation for factory production control (FPC) that aligns with the product and manufacturing process The FPC system should instill confidence in the product's consistent performance, which requires: a) developing documented procedures and instructions for FPC operations based on technical specifications; b) effectively implementing these procedures; c) recording operations and their outcomes; and d) utilizing these results to address deviations, rectify non-conformities, and, if necessary, revise the FPC to eliminate the causes of performance inconsistency.
In subcontracting scenarios, the manufacturer must maintain overall control of the product and ensure access to all necessary information to meet their responsibilities as outlined by this European standard.
When a manufacturer outsources any aspect of a product's design, manufacturing, assembly, packing, processing, or labeling to a subcontractor, the subcontractor's Factory Production Control (FPC) may be considered relevant for the specific product.
The manufacturer who subcontracts all of his activities may in no circumstances pass the above responsibilities on to a subcontractor
Manufacturers with a Factory Production Control (FPC) system that meets the EN ISO 9001 standard and adheres to the current European standard are deemed to fulfill the FPC requirements outlined in Regulation (EU) No 305/2011.
All weighing, measuring and testing equipment shall be calibrated and regularly inspected according to documented procedures, frequencies and criteria
Regular inspection and maintenance of all manufacturing equipment are essential to prevent inconsistencies in the production process due to use, wear, or failure These inspections and maintenance activities must follow the manufacturer's written procedures, with records retained for the duration specified in the manufacturer's FPC procedures.
All incoming raw materials and components must have documented specifications, along with an inspection scheme to ensure compliance When using supplied kit components, their performance consistency must align with the relevant harmonized technical specifications.
Septic tanks must be identifiable and traceable to their production origin Manufacturers are required to implement written procedures that ensure regular inspections of the processes involved in affixing traceability codes and markings.
The manufacturer shall plan and carry out production under controlled conditions
The manufacturer shall establish procedures to ensure that the stated values of the characteristics he declares are maintained The characteristics, and the means of control, are:
Table 4 — Minimum frequency of FPC testing for the septic tank
Name of characteristic Test method or verification Minimum frequency of test
Inlets, outlets and connections According to 4.1.1 1/100 units or minimum
1/week Overall dimensions According to 4.1.2 and 4.1.3 1/100 units or minimum
1/week Structural Behaviour According to 5.1 1/100 units or minimum
1/week Watertightness According to 5.2 and Annex A 1/200 units or minimum
1/month Hydraulic efficiency According to 5.3 Every delivery of raw material and components
Access According to 4.6 1/100 units or minimum
Every week, a durability checklist is conducted for all raw materials and components upon delivery Additionally, a reaction to fire checklist is performed for each delivery to ensure safety standards are met Furthermore, a release of dangerous substances checklist is also required for every delivery of raw materials and components It is important to note that the terms "week" and "month" refer to the production week or month, respectively.
The manufacturer must establish documented procedures for handling non-compliant products All incidents of non-compliance should be recorded as they happen, and these records must be maintained for the duration specified in the manufacturer's written procedures.
If a product does not meet the acceptance criteria, the regulations for non-compliant products will be enforced Immediate corrective actions will be implemented, and any non-compliant products or batches will be isolated and clearly identified.
Once the fault has been corrected, the test or verification in question shall be repeated
All control and test results must be accurately documented, including the product description, manufacturing date, adopted test method, test results, and acceptance criteria, all signed by the responsible individual.
Any control results that do not comply with this European standard must have documented corrective measures taken to address the issue, such as conducting additional tests, modifying the manufacturing process, or discarding or rectifying the product.
The manufacturer shall have documented procedures that instigate action to eliminate the cause of
The manufacturer shall have procedures providing methods of product handling and shall provide suitable storage areas preventing damage or deterioration
The FPC system shall address this European Standard and ensure that the products placed on the market comply with the declaration of performance
Procedure for modifications
Any changes to the product, production process, or FPC system that may impact the declared product characteristics must lead to a reassessment of all affected performance characteristics This reassessment should follow the product type determination process outlined in section 6.2.1.
Where relevant, a re-assessment of the factory and of the FPC system shall be performed for those aspects, which may be affected by the modification
All assessments and their results shall be documented in a report.
One-off products, pre-production products (e.g prototypes) and products produced
Septic tanks that are produced as one-off units, prototypes evaluated prior to full-scale production, and products manufactured in limited quantities (not exceeding one per year) will undergo a specific assessment process.
For type assessment, the provisions of 6.2.1, 3rd paragraph apply, together with the following additional provisions:
— in case of prototypes, the test samples shall be representative of the intended future production and shall be selected by the manufacturer;
— on request of the manufacturer, the results of the assessment of prototype samples may be included in a certificate or in test reports issued by the involved third party
The FPC system for one-off products and those produced in minimal quantities must guarantee adequate raw materials and components for production Relevant provisions regarding these materials will be enforced as necessary Additionally, manufacturers are required to keep records that ensure product traceability.
For prototypes intended for series production, it is essential to conduct an initial inspection of the factory and the FPC prior to the commencement of production or the implementation of the FPC This assessment will evaluate key factors to ensure readiness for mass manufacturing.
During the initial assessment of the factory and Factory Production Control (FPC), it is essential to verify that all necessary resources for achieving the product characteristics outlined in the European standard are available Additionally, it must be confirmed that the FPC procedures, as per the FPC documentation, are effectively implemented and adhered to in practice Furthermore, procedures should be established to demonstrate that the factory's production processes can consistently produce a product that meets the requirements of the European standard, ensuring that the final product is identical to the samples used for verifying compliance with this standard.
Once series production is fully established, the provisions of 6.3 shall apply
Classification
Septic tanks are designated by preferred sizes (NC) on the basis of a minimum nominal capacity of 2 m 3 with nominal capacity differences of 1 m 3 between two consecutive sizes.
Nominal capacity
The volume of water filled up to the outlet level shall be at least of the nominal capacity claimed by the manufacturer, at a temperature of 15 °C ± 5 °C
Marking
The marking shall be durable, accessible and easily legible after installation
The inlet and outlet positions shall be clearly identified
The marking should be preferably on the inner wall of the shaft or when not possible, on the outer wall of the septic tank in the inlet area
The marking must include essential information such as the manufacturer's details and product identification, the relevant EN number, the type of material, the nominal size, the date of manufacture, the name of the laboratory, and, if applicable, the test report number.
Installation instructions
The manufacturer must provide installation instructions for each septic tank in the local language, ensuring clarity for users These instructions should include essential information on plant installation, pipe connections, and the procedures for commissioning and start-up.
Operating and maintenance instructions
The manufacturer shall provide with each septic tank comprehensive operation and maintenance instructions, written in the language of the country in which the septic tank is installed
The manufacturer shall write clear instructions of safety so the operator shall pay attention that nobody falls in the septic tank during the maintenance
Watertightness and nominal capacity tests
General
The watertightness test and nominal capacity test shall be carried out on a complete septic tank.
Capacity test
Sample
The test is carried out on an empty septic tank according to Table A.1.
Procedure
The septic tank shall be placed on an elevated device and secure in place to enable inspection of the base of the septic tank
To ensure proper functioning, the septic tank must be filled to the outlet level with clean water maintained at a temperature of 15 °C ± 5 °C It is essential to accurately record the volume of water used to fill the tank in litres, with a precision of 1%.
Expression of results
The value of the measurement shall be expressed in litres.
Watertightness tests
Selection of the test
One of the watertightness tests in Table A.1 shall be carried out on a complete septic tank whether factory manufactured or assembled from prefabricated components
For ITT, the water test is the reference test
Tank material Concrete GRP, PE, PP, PVC-U, PDCPD, Steel and
Water test
The septic tank shall be placed and secured in place so as to enable inspection of the base of the septic tank
The septic tank, whether it includes an extension shaft or not, must be filled with clean water to the specified water tightness level, which should be at least equal to the top of the tank, after all connections have been sealed.
To ensure optimal performance and account for material saturation, concrete septic tanks must be filled with water for a minimum of 24 hours Following this saturation period, it may be necessary to refill the tank prior to testing The volume of water needed for refilling after a 30-minute test period should then be accurately measured.
Septic tanks constructed from alternative materials do not require a saturation period prior to testing After a duration of 30 minutes, an inspection for leaks must be conducted, and the findings should be documented.
1 top of the septic tank
At the conclusion of the testing period for a concrete septic tank, the volume of clean water needed to elevate the water level to the tank's top will be recorded in litres This volume will then be represented in litres per square meter of the internal wet surface area of the external walls.
For septic tank made of other material, any water leakage shall be recorded.
Air permeability vacuum test
The test is carried out on an empty septic tank (with or without extension shaft)
The septic tank shall be placed on a level surface and laterally supported One of the three pressures given in Table A.2 shall be chosen for the test
The chosen vacuum pressure shall be gradually imposed on the septic tank and held for 3 min to allow the septic tank to absorb the deformation
The value of the variation of the pressure shall be expressed in kPa.
Pneumatic pressure test
The test is carried out on an empty septic tank (with or without extension shaft)
The test for the septic tank can be conducted using one of two methods In the first method, the tank is positioned on a level surface with lateral support, and a pneumatic pressure from Table A.3 is gradually applied and maintained for 3 minutes to allow for deformation absorption, followed by measuring the pressure variation during the specified test period In the second method, the tank is similarly placed and supported, subjected to an initial pneumatic pressure of 30 kPa (0.3 bar) for a minimum of 3 minutes, after which the pressure variation is recorded.
The value of the variation of the pressure shall be expressed in kPa
General
This testing procedure shall characterize the hydraulic efficiency of septic tanks
Polystyrene spherical beads shall be used to simulate settling matter
The parameters to be selected for each capacity of septic tanks are specified in Table B.1
The septic tank shall be tested by a laboratory.
Experimental apparatus
4 mixing tank for suspended particles 10 l 11 sewer
5 water 12 mixing tank for beads + Tween 80 + water
7 polystyrene beads 50 % of wet volume + TWEEN
A constant level tank shall be used to supply the septic tank with clean water
A flow meter shall regulate the flow at the inlet of the septic tank
A mixing tank of a minimum size of 10 l, used for settling sludge tests, shall be installed at 2 m from the inlet of the septic tank.
Synthetic materials used for testing
One type of particles shall be used for the hydraulic testing procedure
Polystyrene beads (P A), containing 50 ppm to 2 000 ppm of anti-static agent shall be used Beads shall not be externally lubricated
Polystyrene beads (P A), size 0,3 mm to 0,4 mm/ 0,4 mm to 0,5 mm equally distributed by weight, density 1,04 shall be used
Polystyrene beads (P B), size 2 mm to 5 mm, density 1,04 shall be used.
Preparation of test
The septic tank shall be installed in the test apparatus in a horizontal way The inlet pipe shall be similar to the type of pipes used for normal operating conditions
Before testing, the septic tank shall be rinsed with clean water and left full of water
The water temperature shall be 15 °C ± 5 °C
The tests shall be carried out on a septic tank full of water with bottom sludge (P B) of 50 % of the septic tank volume
To prepare a solution for a septic tank with a wet volume of V litres, mix Polystyrene beads (P B) at 50% of the nominal capacity, approximately 1,000/3 × NC in kg, and add water to reach the nominal capacity This solution should be pumped into the septic tank through the inlet pipe at a total flow rate between q and 2q During the injection process, the outlet water must be filtered, and the collected beads should be reinjected into the septic tank.
If polystyrene beads (P B) are floating on the water surface, add Tween 80 (detergent) into the septic tank to reduce the surface tension
If some polystyrene beads (P B) are still floating, they shall be removed from the septic tank
After the beads (P B) have been added, maintain the water flow q for a further 30 min
A minimum period of 45 min shall be observed before the beginning of the tests
For a 3 m³ septic tank, prepare a mixture consisting of 1,000 kg of beads (P B) (approximately 1.5 m³), a few drops of detergent to lower the water's surface tension, and enough water to reach a total volume of 3 m³.
Test parameters
The flows in l/s for the different sizes of septic tanks shall be calculated by the following empirical formula: q = 1,5 + (NC – 10) × 0,05 for NC > 10, where
NC = nominal capacity = volume in m 3 ; and q = test flow rate
Table B.1 — Test parameter for preferred sizes
Procedure
A concentrated test suspension consisting of 1 kg of polystyrene beads (P A ), water up to 10 l and 20 g of TWEEN 80 shall be prepared
The septic tank must undergo testing with a continuous water flow for 10 minutes, requiring a total of \$q \times 10 \times 60\$ liters of water For instance, a 3 m³ septic tank would need 420 liters of water During the first 30 seconds of the test, a test suspension should be injected into the water flow, which must be maintained steadily throughout the testing period The outlet water will be screened, and beads collected during the test and for 15 minutes after the water supply ends These beads should then be dried in an incubator at 60 °C and weighed until a constant mass is achieved, with an accuracy of 0.01 g.
The procedure shall be carried out five times during one day Between each test, a minimum rest period of 45 min shall be established.
Calculation of test results
The results shall be expressed by the quantity of beads collected, expressed in grams
The five test results shall be compared to the requirement and four results out of five shall meet the requirement Tolerances on measures shall be 0,1 g
Examples for outlet devices
Openings in internal walls
In case of internal walls, minimum openings should be sufficient to prevent clogging
Test methods for structural behaviour
Selection of test method
To determinate the structural behaviour of a septic tank, one or more method(s) described below and mentioned in Table D.1 shall be used
Table D.1 — Methods for the determination of the structural behaviour
CONCRETE GRP PE STEEL OTHER
Concrete septic tank
Crushing test methods
Table D.2 indicates the crushing test method to be performed according to the shape of the septic tank being tested
Rectangular or trapezoidal shape Vertical cylinder shape Horizontal cylinder shape
NOTE Letters A, B and C correspond to the test method.
Test procedures
The test will be conducted on a vacant septic tank with its cover(s) in place, excluding any extensions or maintenance shafts The schematic representation of this test is illustrated in Figure D.1.
The septic tank shall be placed on a sand bed of granulometry 0-5 mm, water content approximately
(7 ± 2) % by mass and thickness of 6 cm ± 1 This sand bed shall be levelled before the installation of the septic tank
To ensure proper support for the septic tank, a sand bed will be installed on the upper section to account for the thickness of the cover and the tank's inner geometry A loading plate will be used to evenly distribute stress across the top of the septic tank, with a consistent application of stress for a minimum of 5 minutes The load tolerance is set at ± 3%.
The stress shall be applied up to failure
The load F corresponding to the failure shall be noted and expressed in kN/m 2 of the surface submitted to the load, excluding the surface of the cover
Figure D.1 — Scheme of the principle of the Type A test
The test shall be carried out on an empty septic tank without its cover(s) and any extension and/or maintenance shaft
The septic tank shall be placed so that the upper surface (supporting the cover(s)) is in a vertical position
The septic tank shall be placed on a sand bed as defined in D.2.2.1.2
The load on the septic tank must be evenly distributed using a loading plate and an intermediate sand bed that match the specifications outlined in D.2.2.1.2 The loading plate should cover the entire surface of the tank, while the sand bed must be leveled to accommodate the tank's side geometry, as illustrated in Figure D.2.
The load shall be applied gradually in order to obtain the maximum load between 5 min and 15 min The tolerance on the load shall be ± 3 %
The load shall be applied up to failure
The load F corresponding to the failure shall be noted and expressed in kN/m 2 of the surface submitted to the load
Figure D.2 — Scheme of the principle of the Type B test
The test will be conducted on an empty septic tank, ensuring that it is devoid of covers, extensions, or maintenance shafts, as illustrated in Figure D.3.
The septic tank shall be placed on the whole length on a “V” support forming a 150° angle covered by a rubber strip of 10 mm to 20 mm thick
A rubber strip measuring 50 mm in width and 20 mm in thickness will be installed between the loading beam and the septic tank, ensuring that the length of the loading beam is at least equal to that of the septic tank.
The load shall be applied gradually in order to obtain the maximum load between 5 min and 15 min The tolerance on the load shall be ± 3 %
The load shall be applied up to failure
The load F corresponding to the failure shall be noted and expressed in kN
1 rubber strip (10 mm to 20 mm thick)
Figure D.3 — Scheme of the principle of the Type C test
Polyethylene septic tank
General
This test method is applicable for use in dry conditions only.
Vertical load test
The test shall be carried out on an empty septic tank equipped with its cover(s) without any extension
Testing shall be carried out at the temperature of (25 ± 5) °C
The septic tank shall be placed in its normal operating conditions on a sand bed of granulometry 0-
5 mm, water content (7 ± 2) % by mass This sand bed shall be levelled to a thickness of 6 cm ± 1 cm before the installation of the tank
A loading plate will evenly distribute vertical stress across the top of the septic tank, positioned at its center on a 1 cm thick plate If the upper surface of the septic tank is uneven, such as with covers or raised points, adjustments must be made to ensure a level contact with the loading plate.
The load shall be applied gradually in order to obtain the maximum load between 5 min and 15 min The tolerance on the load shall be ± 3 %
The load on the tank shall be increased to the collapse
Variation of h t shall be noted, step by step
The maximum load F shall be noted and converted by dividing by the loaded section
The load per unit area corresponding to the collapse shall be noted and expressed in kN/m 2
4 plate h t distance between the bottom of the septic tank and the axis of the inlet pipe
Determination of mechanical characteristics of test samples used for calculation
Glass Reinforced Plastic
Specimen samples of laminate from the septic tank will be prepared, with exposed edges coated in the same resin used for manufacturing These samples will undergo post-curing in air at a temperature of (50 ± 2) °C for a minimum of 72 hours Following this, the samples will be immersed in water at (50 ± 2) °C for 1,000 hours Additionally, identical samples will be stored in controlled air conditions for 1,000 hours at (20 ± 2) °C The flexural modulus and strength of all samples will be measured according to the EN ISO 14125 standard.
Vacuum test for Glass Reinforced Plastic or steel septic tank
The septic tank must be engineered to endure an external pressure \( P \), determined by a specific formula Additionally, it is essential to test the septic tank against the designed external load under the intended usage conditions, utilizing the same formula for verification.
P is the test pressure in kPa;
The external pressure, denoted as L in kPa, is calculated based on the maximum external load, which includes both vertical or horizontal loads from backfill and hydrostatic loads when applicable The safety factor, represented by f, is set at 1.5 for Glass Reinforced Plastic (GRP) and ranges from 1.3 to 2 for steel.
After calculation of the P value, seal the tank and apply an under pressure equal to P during one minute
No permanent deformation shall occur.
Pit test
Sample
The test will be conducted on an empty septic tank that includes pipe connections for inlet, outlet, and interconnection, along with its cover and any extension or maintenance shafts The schematic representation of this testing principle is illustrated in Figure D.5.
The septic tank must be installed in a watertight test excavation, with the excavation size carefully calculated to prevent side effects It is essential to secure the septic tank to the base of the excavation in accordance with the manufacturer's installation guidelines.
The excavation shall be backfilled with preferably rounded gravel (3 mm to 8 mm)
To simulate wet ground conditions, add water to the top of the septic tank, as defined in Figure D.5.
Procedure
Step 1: Measure the initial internal dimensions of the septic tank
Step 2: Place the septic tank in the test excavation
Step 3: Backfill with gravel up to the level of pipe connections and simultaneously fill the septic tank with water up to the top, after sealing the inlet and outlet pipe works For tanks made of concrete or GRP, the volume of water in the septic tank shall be
For tanks made of other materials, discharge the septic tank and measure the volume of water in the septic tank one day later
Step 4: Check the position of the inlet and outlet pipe works
Step 5: Complete the backfill with gravel up to the maximum depth in accordance with the manufacturer’s installation instructions, including the pedestrian load (2,5 kN/m 2 ), converted to a uniform backfill load Seal the inlet and outlet pipe works and, for a wet ground test, add water in the excavation to the level of the top of the septic tank Step 6: For a septic tank made of concrete or GRP, maintain the test conditions for 24 h For a septic tank made with other materials, maintain the test conditions for 3 weeks Step 7: In wet condition: examine the inside of the septic tank to show the watertightness is maintained Discharge the water from the excavation If the septic tank is watertight, refill with water, and measure any change in the capacity of the septic tank
In dry conditions, inspect the interior of the septic tank, then refill it with the necessary volume of water to reach full capacity and assess any changes in the tank's capacity.
Expression of results 42 Annex ZA (informative) Clauses of this European Standard addressing the provisions of the
For septic tanks made of concrete or GRP, no failure shall occur during the test In addition, no lack of watertightness shall be recorded
For septic tanks made with other materials:
— the variation of the volume of the septic tank (expressed in litres) shall be lower than 20 % of the internal volume of the septic tank;
— the movement of inlet, outlet and interconnecting pipe works shall not lead to a lack of watertightness
Figure D.5 — Scheme of the principle for the pit test
Clauses of this European Standard addressing the provisions of the EU
ZA.1 Scope and relevant characteristics
This European Standard has been prepared under Mandate M/118 “Wastewater engineering products” given to CEN by the European Commission and the European Free Trade Association
When this European Standard is referenced in the Official Journal of the European Union (OJEU), the clauses outlined in this annex are deemed to fulfill the requirements of the applicable mandate under Regulation (EU) No 305/2011.
This annex deals with the CE marking of the prefabricated septic tank intended for the uses indicated in Table ZA.1 and shows the relevant clauses applicable
This annex has the same scope as in Clause 1 of this standard related to the aspects covered by the mandate and is defined by Table ZA.1
Table ZA.1 — Relevant clauses for product and intended use
Intended use: To be used outside buildings for faecal water and organic effluent for a population up to 50 PE
Clauses in this standard related to essential characteristics
Hydraulic efficiency 4.4 - Tested according to Annex B and expressed in g of beads
Watertightness 4.3 - a) Tested according to Annex A; and b) Expressed as “Pass/Fail” together with the test method used
Structural behaviour 4.2 - Calculation or test methods in Annex D
Durability 4.7 - a) Tested according to 4.7 (as appropriate) and the material used; and b) Expressed as “Pass/Fail”
Fire reaction classifications range from A1 to F, where materials can be either classified and declared without testing (CWT) or classified based on the lowest material class according to EN 13501–1, utilizing the specified test methods.
Release of dangerous substance 4.9 - As relevant, according to 4.9
In Member States where there are no regulatory requirements for essential product characteristics related to its intended use, the declaration of product performance for these characteristics is not mandatory.
Manufacturers marketing their products in these Member States are not required to assess or disclose the performance of their products concerning essential characteristics They can utilize the "No performance determined" (NPD) option in the information accompanying the CE marking and in the declaration of performance.
ZA.2 Procedure of attestation of conformity of prefabricated septic tanks
The AVCP system for wastewater treatment plant kits and elements, as outlined in Table ZA.1, was established by EC Decision 97/464/EC on June 27, 1997, and amended by EC Decision 2004/663/EC on September 20, 2004 Table ZA.2 presents the relevant intended uses and corresponding performance levels or classes for these systems.
Table ZA.2 — System(s) of AVCP
Product(s) Intended use(s) Level(s) or class(es) of performance AVCP system(s)
Kits and elements for wastewater treatment plants*
To be used outside buildings for faecal water and organic effluent - 3
For all uses when subject to regulations on reaction to fire
System 1: See Regulation (EU) No 305/2011 (CPR) Annex V, 1.2
System 3: See Regulation (EU) No 305/2011 (CPR) Annex V, 1.4
System 4: See Regulation (EU) No 305/2011 (CPR) Annex V, 1.5
Products and materials that undergo a distinct stage in the production process can enhance their fire reaction classification, such as through the incorporation of fire retardants or the reduction of organic materials.
** Products/ materials not covered by footnote (*)
*** Products/ materials that do not require to be tested for reaction to fire (e.g Products/materials of class A1 according to the Decision 96/603/EC, as amended)
NOTE Prefabricated septic tanks for a population up to 50 PE are considered kits and elements for wastewater treatment plants
The AVCP for wastewater treatment plant kits and elements, as outlined in Table ZA.1, must follow the procedures specified in Tables ZA.3.1 to ZA.3.3, based on the applicable clauses of this or other referenced European Standards The responsibilities of the notified body are confined to the essential characteristics listed in Annex III of the relevant mandate and those that the manufacturer chooses to declare.
Table ZA.3.1 — Assignment of AVCP tasks for prefabricated septic plants under system 1
Tasks Content of the task AVCP clauses to apply
Factory production control (FPC) All essential characteristics of Table ZA.1 relevant for the intended use which are declared
Further testing of samples taken at factory according to the prescribed test plan Reaction to fire 6.3
Tasks for the notified testing laboratory
Determination of the product- type on the basis of type testing (based on sampling carried out by the manufacturer), type calculation, tabulated values or descriptive documentation of the product
All essential characteristics of Table ZA.1 relevant for the intended use which are declared except reaction to fire
Initial inspection of manufacturing plant and of FPC Reaction to fire 6.3.4 Continuous surveillance, assessment and evaluation of FPC Reaction to fire 6.3.5
Table ZA.3.2 — Assignment of AVCP tasks for prefabricated septic plants under system 3
Tasks Content of the task AVCP clauses to apply
Tasks for the manufacturer Factory production control (FPC)
All essential characteristics of Table ZA.1 relevant for the intended use which are declared
Tasks for a notified testing laboratory
Determination of the product- type on the basis of type testing (based on sampling carried out by the manufacturer), type calculation, tabulated values or descriptive documentation of the product
All essential characteristics of Table ZA.1 relevant for the intended use which are declared 6.2
Table ZA.3.3 — Assignment of AVCP tasks for prefabricated septic plants under system 4
Tasks Content of the task AVCP clauses to apply
Factory production control (FPC) All essential characteristics of Table ZA.1 relevant for the intended use which are declared
Determination of the product- type on the basis of type testing, type calculation, tabulated values or descriptive documentation of the product
All essential characteristics of Table ZA.1 relevant for the intended use which are declared 6.2
ZA.2.2 Declaration of performance (DoP)
The manufacturer draws up the DoP and affixes the CE marking on the basis of the different AVCP systems set out in Annex V of the Regulation (EU) No 305/2011:
In case of products under system 1
— the factory production control and further testing of samples taken at the factory according to the prescribed test plan, carried out by the manufacturer; and
The certificate of constancy of performance is issued by a notified product certification body and is based on the determination of the product type through type testing, which includes sampling, type calculation, tabulated values, or descriptive documentation This certification process also involves an initial inspection of the manufacturing plant, factory production control, and ongoing surveillance, assessment, and evaluation of factory production control.
In case of products under system 3
— the factory production control carried out by the manufacturer; and
The determination of the product type is conducted through type testing, which involves sampling by the manufacturer, type calculations, tabulated values, or descriptive documentation of the product, all performed by a notified testing laboratory.
In case of products under system 4
— the factory production control carried out by the manufacturer;
— the determination by the manufacturer of the product-type on the basis of type testing, type calculation, tabulated values or descriptive documentation of the product
The model of the DoP is provided in Regulation (EU) No 574/2014
According to this Regulation, the DoP shall contain, in particular, the following information:
— the reference of the product-type for which the declaration of performance has been drawn up;
— the AVCP system or systems of the construction product, as set out in Annex V of the CPR;
— the reference number and date of issue of the harmonized standard which has been used for the assessment of each essential characteristic;
— where applicable, the reference number of the Specific Technical Documentation used and the requirements with which the manufacturer claims the product complies
The Declaration of Performance (DoP) must include the intended uses of the construction product as per the relevant harmonized technical specifications, a list of essential characteristics defined in those specifications, and the performance of at least one essential characteristic pertinent to the declared uses Additionally, it should detail the product's performance levels or classes, if applicable, based on calculations related to its essential characteristics as determined by the Commission Furthermore, the DoP must address the performance of essential characteristics linked to the intended uses, considering the manufacturer's market intentions For any essential characteristics without declared performance, the designation "NPD" (No Performance Determined) should be included.
Regarding the supply of the DoP, article 7 of the Regulation (EU) No 305/2011 applies
The information referred to in Article 31 or, as the case may be, in Article 33 of Regulation (EC)
No 1907/2006, (REACH) shall be provided together with the DoP
The following gives an example of a filled-in DoP for prefabricated septic tanks
1 Unique identification code of the product-type:
Prefabricated septic tank BWV 714 (concrete)
2 Type, batch or serial number or any other element allowing identification of the construction product as required under Article 11:
3 Intended use or uses of the construction product, in accordance with the applicable harmonized technical specification, as foreseen by the manufacturer:
To be used outside buildings for faecal water and organic effluent for a population up to 50 PE
4 Name, registered trade name or registered trade mark and contact address of the manufacturer as required under Article 11:
Email: anyco.sa@provider.be
5 Where applicable, name and contact address of the authorized representative whose mandate covers the tasks specified in Article 12:
Tel +44987654321 e-mail: anyone.ltd@provider.uk
6 System or systems of assessment and verification of constancy of performance of the construction product as set out in CPR, Annex V:
System 3 for all essential characteristics except reaction to fire
System 4 for reaction to fire
7 In case of the declaration of performance concerning a construction product covered by a harmonized standard:
Notified body number 0001 performed product type testing under system 3 and issued test report 12345/2013
8 No European Technical Assessment has been issued for this product
Essential characteristics Performance Harmonized technical specification
Reaction to fire Class A1 EN 12566–1:2016
Hydraulic efficiency XXX g of beads
Release of dangerous substance NPD
10 The performance of the product identified in points 1 and 2 is in conformity with the declared performance in point 8
This declaration of performance is issued under the sole responsibility of the manufacturer identified in point 4
Signed for and on behalf of the manufacturer by:
(place and date of issue) (signature)
ZA.3 CE marking and labelling
The CE marking symbol shall be in accordance with the general principles set out in Article 30 of Regulation (EC) No 765/2008 and shall be affixed visibly, legibly and indelibly:
— to the prefabricated septic tank;
— to a label attached to it
Where this is not possible or not warranted on account of the nature of the product, it shall be affixed:
The CE marking shall be followed by:
— the last two digits of the year in which it was first affixed;
— the name and the registered address of the manufacturer, or the identifying mark allowing
— the reference number of the declaration of performance;
— the level or class of the performance declared;
— the dated reference to the harmonized technical specification applied as it appears in OJEU;
— the identification number of the notified body;
— the intended use as laid down in the harmonized technical specification applied
The CE marking must be applied to construction products prior to their market introduction, and it may include a pictogram or additional symbols to signify specific risks or uses.
Figure ZA.1 gives an example of the information related to products subject to AVCP under system 3 (all characteristics except reaction to fire) and 4 (for reaction to fire)
“CE marking, consisting of the “CE”-symbol Identification number of the notified test laboratory
Any Co Ltd, P.O Box 21, B–1050 Name and the registered address of the manufacturer, or identifying mark
16 Last two digits of the year in which the marking was first affixed
0012013–07–14 Reference number of the DoP
EN 12566–1:2016 No of European Standard applied, as referenced in OJEU
Unique identification code of the product-type Intended use of the product as laid down in the European Standard applied Level or class of the performance declared
Hydraulic efficiency XXX g of beads
Release of dangerous substances NPD
Figure ZA.1 — Example CE marking information of products under AVCP system 3 (all characteristics except reaction to fire) and 1 (reaction to fire)
[1] EN ISO 9001, Quality management systems — Requirements (ISO 9001)
[2] EN 476, General requirements for components used in drains and sewers