GERMAN ATV-DVWK RULES AND STANDARDS

Standard ATV-DVWK-A 142E

Sewers and Drains in Water Catchment Areas

November 2002 ISBN 3-937758-42-9

Publisher Company of ATV-DVWK German Association for Water, Wastewater Theodor-Heuss-Allee 17 D-53773 Hennef Postfach 11 65 D-53758 Hennef Tel. +49 (0)22 42 / 8 72-120 Fax:+49 (0)22 42 / 8 72-100 E-Mail: lumma@atv.de Internet: http://www.gfa-verlag.ded

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User Notes This Standard is the result of honorary, technical-scientific/economic collaboration which has been achieved in accordance with the principles applicable therefor (statutes, rules of procedure of the ATV-DVWK and the Standard ATV-DVWK-A 400E). For this, according to precedents, there exists an actual presumption that it is textually and technically correct and also generally recognised. The application of this Standard is open to everyone. However, an obligation for application can arise from legal or administrative regulations, a contract or other legal reason. This Standard is an important, however, not the sole source of information for correct solutions. With its ap-plication no one avoids responsibility for his own action or for the correct application in specific cases; this applies in particular for the correct handling of the margins described in the Standard. The German Association for Water, Wastewater and Waste, ATV-DVWK, is the spokesman in Germany for all universal questions on water and is involved intensively in the development of secure and sustainable water management. As politically and economically independent organisation it operates specifically in the areas of water management, wastewater, waste and soil protection. In Europe the ATV-DVWK is the association in this field with the greatest number of members and, due to its specialist competence it holds a special position with regard to standardisation, professional training and information of the public. The ca. 15,000 members represent the experts and executive personnel from municipalities, universities, engineer offices, authorities and businesses. The emphasis of its activities is on the elaboration and updat-ing of a common set of technical rules and standards and with collaboration with the creation of technical standard specifications at the national and international levels. To this belong not only the technical-scientific subjects but also economical and legal demands of environmental protection and protection of bodies of waters. Publisher: ATV-DVWK Deutsche Vereinigung für Wasserwirtschaft, Abwasser und Abfall e.V., Theodor-Heuss-Allee 17, D-53773 Hennef Marketing: GFA Gesellschaft zur Förderung der Abwassertechnik e.V., Hennef Setting and printing (German original): DCM, Meckenheim © GFA Gesellschaft zur Förderung der Abwassertechnik e. V., Hennef 2002 All rights, in particular those of translation into other languages, are reserved. No part of this Standard may be reproduced in any form - by photocopy, microfilm or any other process - or transferred into a language usable in machines, in particular data processing machines, without the written approval of the publisher.

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Foreword Sewers and drains must be so laid and operated that a contamination or any other adverse change to the soil or surface waters is avoided. This applies to a particular degree for sewers and drains in catchment ar-eas of water procurement systems which serve the public water supply (water catchment areas). In order to describe and lay down the special requirements, the German Association for Water, Wastewater and Waste (ATV-DVWK), the German Technical and Scientific Association for Gas and Water (DVGW) and the German Association for Drinking Water Reservoirs [Arbeitsgemeinschaft Trinkwassertalsperren e. V]. (ATT) have produced this Standard in a joint working group. It contains the requirements and conditions which, according to previously available experience, are to be observed with the establishment and operation of sewers and drains in water catchment areas. The statements contain regulations for the protection of groundwater and surface waters (barrier reservoirs). The Standard deals with planning, provides information for implementation and regulates maintenance. At-tention is drawn to the examples in Advisory Leaflet ATV-M 146 carried out in practice. The Standard replaces the version from 1992. Revision was necessary due to new findings with regard to the hazard potential of wastewater as well as new technical developments. It also serves for the adoption of EN 752-3 and EN 752-7 through the ATV-DVWK Set of Rules and Standards. The financial effects of this Standard are difficult to estimate quantitatively. Compared with the previously valid version of the Standard (1992), however, a cost reduction is more likely to be expected.

Authors This Standard has been elaborated by the ATV-DVWK Working Group ES-5.6 “Sewers in Water catchment Areas” within the ATV-DVWK Specialist Committee ES-5 “Design of Drainage Systems”. Working Group ES-5.6 has the following members: Dipl.-Ing. Jörg Cloesters, Köln Dipl.-Ing. Ulrich Edeling, Berlin Dr.-Ing. Ulrich Güttler, Essen Dipl.-Ing. Horst Kirchmaier, Frankfurt/Main Dipl.-Ing. Karsten Körkemeyer, Bochum Dipl.-Geol. Berthold Niehues, Bonn Dipl.-Ing. Hardy Loy, München Dipl.-Ing. Frank Rommel, Erfurt Dr.-Ing. Lothar Scheuer, Gummersbach Prof. Dr. Jürgen Wagner, Spiesen Ltd. BD Dr.-Ing. Wolfgang Wagner, Saarbrücken (Chairman) ORBR Dipl.-Ing. Heinz Wieching, Münster

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Contents User Notes 2

Foreword 3

Authors 3

1 Area of Application 5

2 Definitions 5

3 Measures for the Protection of Surface Waters 5

3.1 Protective Zone I (Catchment Area) 5

3.2 Protective Zone II (Narrower Protective Zone) 6

3.2.1 General 6

3.2.2 Assessment of the Hazard Potential of Sewers and Drains 6

3.2.3 Planning Principles 7

3.2.3.1 General 7

3.2.3.2 Selection of the Discharge System 7

3.2.3.3 Requirements on Sewers and Drains 8

3.2.3.4 Requirements on Shafts 9

3.2.4 Production of Sewers and Drains 9

3.2.4.1 Building Materials and Components 9

3.2.4.2 Construction Work 9

3.2.4.3 Tests for the Acceptance of New Construction 10

3.2.5 Disused Sewers and Drains 12

3.2.6 Planning and Production of Private Property Drains 12

3.2.7 Operation of Sewers and Drains 12

3.2.7.1 General 12

3.2.7.2 Inspection 13

3.3 Additional Protective Zone (Protective Zone III) 13

4 Legal Provisions, Technical Rules and Literature 14

4.1 Legal Provisions 14

4.2 Technical Rules 14

4.2.1 DIN, EN, ISO Standard Specifications 14

4.2.2 ATV-DVWK Rules and Standards 15

4.2.3 DVGW / LAWA Rules and Standards 15

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1 Area of Application This Standard is to be applied for both already ex-isting water protective zones for groundwater, springs and reservoirs (Protective Zones I – III) and also for catchment areas of water procurement systems for which no water protective zone has been laid down. It is also to be applied analogously to qualitative medicinal spring protective zones. In quantitative medicinal protective zones the effects of interferences to the soil on the hydraulic system and the individual character of the medicinal spring are all important. These assessments are subject to separate considerations to the extent that the depths of interference in accordance with the [German] Protective Zone Ordinance are ex-ceeded (see LAWA [Federal German States Work-ing Group, Water] Directive). The regulations and recommendations given below apply fundamentally for new sewers and drains and for those to be rehabilitated, including the as-sociated shafts and other structures of the local drainage system and the private property drainage system both in the public and private sectors, which are operated as gravity or pressure pipe-lines. With this it supplements the regulations of EN 476, EN 1610, EN 752, of Advisory Leaflet ATV-M 101 and Standards ATV-A 105E, ATV-A 125E, ATV-DVWK-A 127E, ATV-A 128E, ATV-DVWK-A 139E, ATV-A 140E, ATV-A 147E and ATV-DVWK-A 157E. For existing sewers and drains (commissioned be-fore this Standard came into force) it is to be examined, dependent on the local conditions, to what extent the Standard is to be applied.

2 Definitions Water catchment area Catchment areas of water procurement systems (wells, springs, barrier reservoirs) of the public drinking water supply system. Upstream coffer dam As a rule a reservoir with a barrier structure placed immediately upstream of a barrier reservoir. Design capacity of a reservoir Ratio of the storage volume to the mean annual water inflow. With carryover storage [storage for more than one year] the ratio is greater than 1.

Double-walled pipe systems Pipe systems made up from two separately manu-facture pipes which are not connected to each other (medium pipe / jacket pipe). Semi-double-walled pipe systems Single-walled pipe system with hollow spaces in the pipe wall which allow a monitoring for leaks. Petrography Scientific branch of geology which is concerned with the composition of rocks, their natural inci-dence, and in particular, also their formation and transformation.

3 Measures for the Protection of Surface Waters

3.1 Protective Zone I (Catchment Area)

Protective Zone I for groundwater is to ensure the protection of drinking water procurement systems and their immediate vicinity against any contami-nant and encroachment (see DVGW Standard W 101). The discharge of wastewater through Protective Zone I and, with this, the establishment of sewers and drains is inconsistent with the requirements of water pollution control. Should, in the public inter-est, sewers and drains having to be established within the area of Protective Zone I due to compel-ling local and technical circumstances, then the drawing off of water is to cease and the water sup-ply otherwise ensured. Protective Zone I for reservoirs is to ensure the protection of barrier reservoirs from any en-croachment (see DVGW Standard W 102). The discharge of wastewater through Protective Zone I of a barrier reservoir and, with this, the es-tablishment of sewers and drains is inconsistent with the requirements of water pollution control. Should, in the public interest, sewers and drains having to be established within the area of Protec-tive Zone I due to compelling local and technical circumstances, requirements are to be placed on the construction and operation which go beyond the level of requirements for Protective Zone II.

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3.2 Protective Zone II (Narrower Protective Zone)

3.2.1 General

Protective Zone II for groundwater is to ensure the protection from contamination due to pathogenic micro-organisms as well as from other encroach-ments which, with small flow durations and stretches to the drinking water procurement sys-tem, are hazardous (see DVGW Standard W 101). Protective Zone II for barrier reservoirs is to ensure the protection of the reservoir and the surface wa-ters flowing into it against encroachments which emanate from human activities and installations, in particular through direct discharges, flooding and erosion, (see DVGW Standard W 102). Due to the hazard potential the discharge of waste-water within the area of Protective Zone II for groundwater and barrier reservoirs is, as a rule, not acceptable. However, if sewers and drains have to be established due to compelling local and technical circumstances within Protective Zone II, then these are to be limited to the extent neces-sary in the public interest. The responsible water authorities and the water supply companies con-cerned are to be involved already with preliminary investigations. Attention is drawn to official ap-proval in accordance with the regulations under [German] Federal State law.

3.2.2 Assessment of the Hazard Potential of Sewers and Drains

At the forefront of planning measures a hydro-geological expert opinion for the assessment of the hydrogeological hazard potential is fundamentally required. The hazard potential is determined by a large number of individual factors which are asso-ciated with various risk components and which can have different effects dependent on local condi-tions. In particular the following are be mentioned: • type and condition of the sewers and drains, • type and quantity of the wastewater, • topography (in particular with barrier reser-

voirs), • subsoil properties (hydrogeological conditions), • danger of subsidence (e.g. coal mining).

In general a very high hazard potential exists with: • pressure pipelines, • commercial and industrial wastewater, • slight natural protective effect of the subsoil, • severe settling movements of the subsoil (e. g.

coal mining), • intersection of surface waters. In these cases very high requirements are to be placed on the selection of the respective discharge system (see Section 3.2.3.2). With the assessment of the natural protective ef-fect of the subsoil the following are to be taken into account: • soil conditions (e. g. nature, type, substance

and permeability of the soil), • geological conditions (e. g. loose-/compact

rock, petrography, thickness of layers, compac-tion conditions, tectonics),

• hydrogeological conditions (e. g. interstitial/ fissure/karst aquifer, lesser aquifer, aquiclude, groundwater cover, permeability, confined/ unconfined conditions, retention times, ground-water levels, isopiestic lines).

Due to the need for protection of the aquifer and taking into account the increased purification ca-pacity of the unsaturated zone of the soil, the pro-tective effect of the groundwater covering layers is to be given special significance. Important indica-tions for a low protective effect of the groundwater cover are, for example: • small separation between the invert of the

sewer and the surface of the groundwater with mean, highest groundwater level (MHGL),

• fissured or karst compact rock, gravel, coarse sand, high permeability.

In protective zones for barrier reservoirs the follow-ing factors are above all to be involved in the de-termination of the hazard potential: • distance to surface water, • danger of flooding, • slope of the terrain, • upstream coffer dams, • capacity of the reservoir, • absence of impoundment layers. These are, as a rule, of greater relevance than the above mentioned hydrogeological characteristic values.

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In accordance with the assessment of all factors an evaluation of the therefrom resultant hazard po-tential for the groundwater takes place. Sensitivity analyses with regard to the worst-case considera-tions (i.a. for pollutant breakthrough) should be produced within the scope of the evaluation. Also as result of the hydrogeological expert opinion a duplicatable, justified classification of the hazard potential must be carried out which leads to the fol-lowing assessment (comp. Tab. 1): • very high, • high, • less high.

3.2.3 Planning Principles

3.2.3.1 General With new construction or the rehabilitation of sew-ers and drains the greatest care is to be applied with the selection of the drainage system. With this comprehensive and thorough deliberations are to be carried out and hydrogeological, hydrological, drainage engineering and geological factors con-sidered. Only then should one decide case by case on a separate or combined sewer system or modi-fied forms of these. With the decision for a combined sewer system the special concerns of water pollution control are to be taken into account, in particular combined wastewater payments are to be addressed before discharge. With this it is to be examined whether a pollution load reduction which goes beyond the re-quirements of Standard ATV-A 128E is necessary. The route of the pipeline is to be so chosen that terrain and subsoil conditions unfavourable for wa-ter pollution control are avoided. The greatest pos-sible separation between sewer and and/or the surface water is to be strived for. Encroachment into the subsoil is to be minimised. In this connection pipe driving technology and trenchless laying (see EN 12889) as well as vac-uum drainage (see EN 1091) are to be sought as variants for the construction work.

The pipeline zone is to be so formed that a move-ment of the groundwater along the pipeline zone, which goes beyond the natural local conditions, is to be avoided. Placing of sewers and drains on pile foundations is to be avoided in order to prevent a movement of pollutants along the pile shaft, unless a threat can be excluded due to the assessment of the hazard potential (see Section 3.2.2). Processes, which are employed for renovation and repair, must have been tested in accordance with the German Institute for Structural Engineering (DIBt) approval principles for the selection and as-sessment of rehabilitation processes with regards to the effects on the soil and surface water condi-tions (Notice of Conformity). Testing applies for the environmental compatibility also for the duration of installation, working and structural hardening, and for structural engineering qualification. It is to be ensured that the rehabilitated system corresponds analogously with the requirements in accordance with Section 3.2.3.3. Injection and venting processes, due to the poten-tial risks associated with the application of injection medium (venting medium) and also in the later op-erating phase, require the expert verification of the certification of the product in specific cases of ap-plication. With the planning, account is to be taken of the special requirements and loadings which re-sult from the regular repeat testing such as, for ex-ample, continuously testable pipeline systems and sections, appropriate inspection openings, possi-bilities for closure etc. Whenever the local conditions permit connecting sewers are to be connected to shaft structures. Preferably preformed connections are to be em-ployed for connecting pipes and shafts. Attention is drawn to the specifications of EN 1610 in combina-tion with ATV-DVWK-A 139E.

3.2.3.2 Selection of the Discharge System

The selection of the discharge system takes place on the basis of the hazard potential determined (see Section 3.2.2). Following discharge systems are, depending on the hazard potential, possible (see Tab. 1):

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Table 1: Selection of the discharge system related to the hazard potential

Hazard potential Discharge system (with observation of Section 3.2.3.3)

Very high • Double-walled pipe systems (separation between medium and jacket pipes must be sufficiently large so that leakage and seepage water can flow unhindered; subsequent examination of the intervening space must be possible)

• Vacuum systems

• Continuous leak monitoring systems

High • Single-walled pipe systems with increased level of safety (mineral encapsulation, monitoring of sleeves, semi-double-walled solutions or similar)

Less high • Single-walled systems

3.2.3.3 Requirements on Sewers and Drains

Local constraints are to be taken into account in each individual case for the selection of system and material for sewers and drains. The advan-tages and disadvantages of the available alterna-tives are to be weighed against each other with the decision process for the determination of the suit-able system and material. With this decision proc-ess the following assessment criteria are to be taken into account, which are to be weighted for the individual case depending on the individual risk components: • Ability of the of the pipe connection to bend, • Shear strength of the pipe connection, • Number of pipe connections, • Corrosion resistance against the medium to be

carried, aggressive soils and water, • Service life, • Behaviour with regular loading and overloading

(fracture and deformation behaviour), • Sensitivity to transport damage, • Storage capability before installation, • Requirements with regard to laying technique, • Examination of the suitability for acceptance of

pipelines and pipe connections, • Security of the connection (e. g. interaction of

sealing material, acceptance of loads in the ax-ial and transverse direction),

• Quality assurance of materials, pipes and sys-tems,

• Possibilities for rehabilitation, • Permeation of • pollutants through the pipe walls and connec-

tions,

• Possibilities of determining leaks (leak warning system).

With regard to the employment of double-walled systems the following requirements are to be addi-tionally mentioned: • To avoid an uncontrollable transfer of load from

the jacket to the medium pipe, which has not been taken into account statically, appropriate design precautions are to be taken with rigid jacket pipes such as, for example:

• The outside diameter of the inner pipe, includ-ing the spacers, must be at least 10 % smaller than the inside diameter of the outer pipe.

• Spacers with predetermined breaking points so that an unacceptable loading of the medium pipes is excluded.

• In the case of flexible jacket pipes possible de-formation is to be taken into account with the selection of the medium pipe.

• With pressure pipelines the jacket pipe must be so designed that, with failure of the medium pipe, it can also serve as pressure pipeline.

• Static verification is to be produced that, in the case of a leakage of the protective pipe, the medium pipe cannot float or a flotation remains without damage.

Double-walled pipe systems with a very high haz-ard potential as well as single-walled pipe systems must satisfy the following minimum requirements; for double-walled pipe systems with a less high hazard potential these are recommended: • The seals are either to be attached solidly to

the pipes or fixed in chambers specially cre-

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ated for this (Rollring connections are not per-mitted). With mutual bending as well as with shear loading the requirements of EN 476 are to be met.

• The verification for the pipe connection is to be carried out within the scope of initial testing and outside monitoring.

• Pipes and pipe connections must remain leak-proof (factory test) up to a pressure of 240 kPa (= 2.4 bar). Each individual pipe must be sub-jected to a qualification test following manufac-ture. This qualification test must be suitable to provide verification that the two above given requirements are met. This verification can be produced through a leak testing of each indi-vidual pipe.

• If pipes are subjected to a test pressure of at least 500 kPa (= 5 bar), testing of each twenti-eth pipe suffices. The pipe manufacturer must then, however, be certified in accordance with EN ISO 9001, whereby a quality assessment within the scope of this certification is a pre-requisite.

• With rigid pipes the stability verification is to be based on a 20 % increased safety coefficient referred to Class A of the Standard ATV-DVWK-A 127E.

• Verification is to be provided that high pressure cleaning equipment can be employed without damage.

• Bedding is to be formed in accordance with EN 1610 and ATV-DVWK-A 139E Bedding Type I.

• For flexible pipes a deformation δ of max. 4 % is permitted. The boundary value applies as 90 % fractile.

• With plastic pipes the following continuous in-ternal minimum wall thicknesses are to be maintained for the cover of operational (high pressure cleaning equipment) and laying conditioned loading:

- HDPE: 3.5 mm - PP: 3.5 mm - PVC: 2.5 mm

These specifications apply for sewers and drains which serve for permanent wastewater discharge. For stormwater sewers and overflow channels the structural requirements can be reduced. Then at least the requirements for Water Protective Zone III are to be met. The manufacture of street outlets takes place in accordance with the relevant standard specifica-tions and directives. The provisions of this Stan-dard for stormwater sewers and overflow channels

apply for connecting drains from street outlets to the sewer.

3.2.3.4 Requirements on Shafts The relevant standard specifications and technical rules are to be observed with regard to the re-quirements on shafts and for their manufacture. In particular attention is drawn to EN 476 and Stan-dard ATV-DVWK-A 157E. As a rule, the medium pipes are to be led closed through the shaft. Facilities for watertightness testing during opera-tion are to be planned. The dimensions of the shaft must be so selected that sufficient room is available for sound monitor-ing of the medium and jacket pipes from the shaft. The shafts are to have as few as possible joints. Drop structures with external small flow bypass are not permitted. Subsidence should as far as possible be excluded. With subsidence that nevertheless takes place no leaks may occur (ATV-DVWK-A 157E Chap. 3.2).

3.2.4 Production of Sewers and Drains

3.2.4.1 Building Materials and Components

Building materials and components must at the least satisfy the requirements in accordance with EN 1610 and ATV-DVWK-A 139E. In addition they may contain no water hazardous substances which can be washed out (e.g. with pipe coating, pipe bedding and trench backfill). Pipes employed must be capable of inspection us-ing normal TV camera techniques (“light absorp-tion effect”).

3.2.4.2 Construction Work Further to the specifications in EN 1610 and ATV-DVWK-A 139E the following details are to be ob-served: It is pointed out to all those involved in the con-struction that the project is to be carried out in a water catchment area. The construction measure

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is to be completed rapidly. No hazarding of surface waters may arise from construction site activities. Only such firms are to be tasked which fulfil the cri-teria of the RAL Quality Assurance GZ 961. In this case the customer has to make use of a system for the examination of suppliers or firms in accordance with Article 30 of the EC Directives 93/38/EEC and 98/4/EC. The Güteschutz Kanalbau e. V. [German Association for Quality Protection for Sewer Con-struction] is such a system. The auxiliary construction material used may not be water hazardous. Particular care must be taken with the employment of construction machinery and equipment. Vehicles and construction machinery are to be secured against loss of fuel and oil, construction machinery is to be checked each working day for this; minor repairs are to be carried out immediately. Other-wise the equipment is to be exchanged. Electrically powered construction machinery is preferred to those with internal combustion engines. The em-ployment of biodegradable hydraulic oils is to be preferred in hydraulic units. Customers’ supervisory personnel should be pre-sent on site during critical phases of the construc-tion work. So far as the storage of materials subject to ero-sion is necessary for the implementation of con-struction, this must be limited by time and space to the necessary degree and washing away excluded by suitable precautions. As a rule, with construction work, the following are not acceptable: • the carrying out of cleaning, maintenance and

repair tasks on construction machinery, equip-ment and vehicles as well as refuelling,

• storage and decanting of water-hazardous sub-stances (e.g. fuels, lubricants),

• establishment of workshops, living quarters and storage sites,

• toilet facilities. If the distances to toilet facilities outside Protective Zone II are unreasonably far, then transportable toilet facilities with sealed collection tanks are to be erected, fae-ces are to be removed demonstrably and regu-larly and fed to a central sewage treatment plant,

• percolation of wastewater and harmfully pol-luted precipitation water,

• fixed preparation facilities for construction ma-terials.

• construction site facilities are to be avoided with barrier reservoirs. If, for compelling rea-sons, this is not possible, the separation to sur-face waters must be at least 20 m.

Further details are to be taken from the respective Protective Zone Ordinance.

3.2.4.3 Tests for the Acceptance of New Construction

Following and with the production of pipe bedding and side backfilling the degree of compaction is to be determined and documented. Attention is drawn to Standard ATV-DVWK-A 139E. Visual inspections and watertightness tests are to be carried out following completion of all construc-tion measures and before commissioning. Only such firms which fulfil the criteria of the RAL Qual-ity Assurance GZ 961 should be tasked with im-plementation. In this case the customer has to make use of a system for the examination of sup-pliers or firms in accordance with Article 30 of the EC Directives 93/38/EEC and 98/4/EC. The Güteschutz Kanalbau e. V. [German Association for Quality Protection for Sewer Construction] is such a system. For visual inspection the notes in Advisory Leaflet ATV-M 143E Parts 1 and 2 are to be observed. In general the provisions in accordance with EN 1610 in combination with Standard ATV-DVWK-A 139E apply for the watertightness testing of gravity systems. With deviation from or supplementation of the there described test criteria the following conditions are to be taken into account: • testing may only be carried out by a qualified

specialist firm and not by the construction firm itself.

• the responsible water authority and the water supply company involved are to be involved in the testing.

• shafts are to be tested by filling with water up to the upper edge of the shaft in accordance with EN 1610 and ATV-DVWK-A 139E.

• an informative test protocol on the watertight-ness testing, based on Advisory Leaflet ATV-M 143E Part 6, which makes the testing compre-hensible for the customer, is to be produced in situ.

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• prerequisite for the implementation of an infil-tration testing is a groundwater level which lies above the crown of the pipe and at least corre-sponds with the maximum possible position of the groundwater level in the sewer network. If the existing water level is not sufficient for this test, the pressure on the test object due to the groundwater can possibly be increased through the application of a vacuum in the test space. The amount of the vacuum required re-sults from the difference of the maximum pos-sible position of the water level and the level of the groundwater. Following the application of the vacuum for 45 min, infiltrated or infiltrating groundwater is to be investigated by means of visual inspection. A visible entry of water is not permitted.

• Pressure pipelines including the jacket pipe are to be tested in accordance with EN 805; vac-uum pipes in accordance with EN 1091. The testing times are to be increased by 50 % in comparison with the testing of facilities outside Protective Zone II. Preliminary tests and pres-sure drop tests are to be carried out with pres-sure pipelines.

• Gravity pipelines with a depth of more than 5 m may not be tested using air but only with water, taking into account the above given extension of test time. Testing is then to be correspon-dent with a water filling up to the upper edge of the shaft or to the maximum possible water level. Test pressures above 50 kPa (= 0.5 bar) are therefore permitted.

• watertightness testing of pipe connections only is fundamentally inadmissible.

• the following conditions are to be taken as the basis for water, air overpressure and air vac-uum tests (see Tables 2 – 4).

• for the determination of test times in accor-dance with Tables 3 and 4 for non-circular pro-files, annular spaces of double-walled pipe sys-tems and test equipment for pipe connections the following applies:

AV·4dE =

with dE [m] Effective diameter V [m3] Volume of the test space A [m2] Wall area of the test space,

wetted inner surface

Table 2: Test conditions for water pressure testing

Test pressure hydrostatic pressure through filling the shaft to the upper edge, related to the crown of the pipe min. 10 kPa (= 100 mbar)

Prefilling time not laid down, normally 1 h Test duration 45 min Permitted water addition

0.15 l/m2 (pipelines) 0.2 l/m2 (pipelines including shafts) 0.4 l/m2 (Shafts)

(m2 describes the wetted inner surface) Table 3: Test conditions for air overpressure testing

P0 ∆p Test time t in min in kPa

(in mbar) DN 100 DN 200 DN 300 DN 400 DN 600 DN 800 DN 1000

20 (200)

1,5 (15) 2.5 5 7 10 14 19 24

10 (100)

1,5 (15) 3.5 7 10 14 21 28 35

Intermediate values and test times for larger nominal widths can be calculated using the following formulas: for p0 = 20 kPa: t = 24 d in min (with internal diameter d in m) for p0 = 10 kPa: t = 34.5 d in min (with internal diameter d in m) With t ≤ 5 min rounding up is to the next half minute and with t > 5 min to the next full minute.

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Table 4: Test conditions for air vacuum testing

P0 ∆p Test times t in min in kPa

(in mbar) DN 100 DN 200 DN 300 DN 400 DN 600 DN 800 DN 1000

-20 (-200)

1.1 (11) 2.5 5 7 10 14 19 24

-10 (-100)

1.1 (11) 3.5 7 10 14 21 28 35

Intermediate values and test times for larger nominal widths can be calculated using the following formulas: for p0 = -20 kPa: t = 24 d in min (with internal diameter d in m) for p0 = -10 kPa: t = 34.5 d in min (with internal diameter d in m) With t ≤ 5 min rounding up is to the next half minute and with t > 5 min to the next full minute.

In addition it applies that, for gravity sewers and drains, the watertightness testing both with water and with air may stretch over a maximum of one reach and a maximum of 100 m. If there is a re-quirement to test reaches or sewer sections > 100 m together then the test times are to be mul-tiplied by the factor from the length L of the test section in metres divided by 100. All sewers and drains, tests and acceptances are to be documented.

3.2.5 Disused Sewers and Drains

Permanently disused sewers and drains must be removed or have their hollow spaces filled. Plug-ging materials with organic bonding agents are not permitted.

3.2.6 Planning and Production of Private Property Drains

The provisions of DIN 1986 and EN 752 are rele-vant for planning and construction of sewers and drains for buildings and private properties. If such facilities have to be established in Protec-tive Zone II due to special local conditions then the increased requirements of this Standard are to be fulfilled for building drains and laterals. In deviation from this single-walled systems can be sufficient in justified individual cases, in particular in catchment areas. The laying of inaccessible building drains, for ex-ample under the floor of buildings, is not permit-ted. The conditions of Section 3.2.4.3 apply for testing.

It is to be ensured that a watertightness testing off building drains and laterals is possible through suitable measures such as an inspection/cleaning access fitting or an inspection shaft.

3.2.7 Operation of Sewers and Drains

3.2.7.1 General Standards ATV-A 140E and ATV-A 148E, Advi-sory Leaflet ATV-M 143E and DIN 1986 are to be observed for operation including servicing and maintenance. The requirements for the harmless discharge of wastewater are specified therein. With sewers and drains in water catchment areas operating personnel – over and above training re-ceived for sewer operation - are to be made famil-iar with the special conditions and requirements within the protective zones. For this instruction is to be carried out at least once a year. The following are to be kept available perma-nently on site: • inventory plans of the sewers and drains, • approvals, authorisations and other adminis-

trative decisions under water law, • [German] Protective Zone Ordinance with pro-

tective zone plan, operating instructions includ-ing description of measures in case of abnor-mal occurrence (alarm, catastrophe plan).

The documents are also to be made available to the operator the water catchment area. The treatment process is to be so selected that no damage to pipes and pipe connections can occur.

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3.2.7.2 Inspection Under the term “inspection” are to be understood measures for the recording and evaluation of the actual status of the wastewater system. Here op-tical inspection (visual examination) and the wa-ter tightness test have particular significance. Inspection is to be carried out and logged at regu-lar intervals dependent on the local conditions and on the type and condition of the sewers and drains. The water supply company is to be in-formed of the measure and, if necessary, is to take part. The inspection intervals are to be de-termined in agreement with the water authorities. A first repeat of the watertightness is to be carried out after 2 years, others are to be carried out, as a rule, every 5 years after the first. Between these an optical inspection is to be carried out which can be replaced by a watertightness test. Depending on the type and loading of the sewers and drains shorter intervals between optical in-spections and watertightness tests can become necessary. With the inspection of double-walled pipe systems, in addition to the medium pipe, the jacket pipe is also to be tested. Time intervals for the inspection of private property drainage sys-tems are to be taken from DIN 1986-30. Attention is drawn to Section 3.2.4.3 with regard to the test arrangements so far as no other requirements are laid down by the operator in agreement with the water authorities (e.g. admissibility of tests of pipe connections). The criteria for testing of pressure drains are to be determined for the individual case.

3.3 Additional Protective Zone (Protective Zone III)

Protective Zone III for groundwater is to ensure the protection against far reaching impairments in particular against non- or difficult degradable chemical or radioactive contamination (see DVGW Standard W 101). Protective Zone III for barrier reservoirs is to en-sure the protection of the reservoirs and their af-fluent from far reaching impairment from the catchment area (see DVGW Standard W 102). In Protective Zone III the laying and operation of sewers and drains taking into consideration of the necessary measures for the protection of surface waters is fundamentally permitted.

The general planning principles for sewers and drains listed in Section 3.2.3.1 apply analogously for Protective Zone III. With the employment of Injection and venting process, however, no spe-cialist verification of the certification of the prod-ucts is necessary in the specific case. As a rule, in Protective Zone III, single-walled sewers and drains in accordance with the rele-vant standard specifications and directives are sufficient, so far as particular situations (hydro-geological conditions, intersection with rail facili-ties, roads, surface waters etc.) do not demand other solutions. In the immediate vicinity of the boundaries of Pro-tective Zone II or with large-area sensitive subsoil conditions (e. g. open karst), similar or the same structural requirements as in Protective Zone II can be appropriate in the individual case, whereby the hydrogeological expert opinion for the determination of the hazard potential should produce clarity (Section 3.2.2). If the protection requirement of surface waters in Protective Zone III is also not as high as in Pro-tective Zone II, there are nevertheless pollutants which, even with longer flow times and longer flow paths retain their harmful properties. There-fore an increased security of the surface waters must be undertaken which, as a rule, is to be en-sured through intensive surveillance and monitor-ing of the sewers and drains. A repeat of the watertightness test is to be carried out after 2 years and, as a rule, is to be repeated every 15 years. Between these two optical in-spections are to be carried out which can be re-placed by watertightness tests. Depending on the type and loading of the sewers and drains shorter intervals for optical inspections and watertight-ness testing are required. Attention is drawn to Advisory Leaflet ATV-M 143E Part 6 with regard to the test arrangements so far as no other re-quirements are laid down by the operator in agreement with the water authorities. Tests of the pipe connections are recognised in place of the testing of the complete pipeline, if another test is not technically or economically justifiable.

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4 Legal Provisions, Technical Rules and Literature [If there is no known English translation of a specific document a courtesy translation is provided in square brackets]

4.1 Legal Provisions

93/38/EEC: Directive of the Council dated 14 June 1993 on the Co-ordination of the Award of Contract by Customers in the Field of Water, En-ergy and Traffic Supply as well as in the Tele-communication sector. 98/4/EC: Directive of the European Parliament and the Council dated 16 February 1998 for the Amendment of Directive 93/38/EEC on the Co-ordination of the Award of Contract by Customers in the Field of Water, Energy and Traffic Supply as well as in the Telecommunication sector.

4.2 Technical Rules

4.2.1 DIN, EN, ISO Standard Specifications

DIN 1986 Beiblatt [Supplement 1] Entwässerungsanlagen für Gebäude und Grund-stücke – Stichwortverzeichnis; [Drainage and sewerage systems for buildings and plots of land – Index]; July 1998 DIN 1986-3 Drainage and sewerage systems for buildings and plots of land; Part 3: Rules for service and maintenance; July 1982 DIN 1986-4 Drainage and sewerage systems for buildings and plots of land; Part 4: Use of sewer pipes and fittings made from different materials; November 1994 DIN 1986-30 Drainage and sewerage systems for buildings and plots of land; Part 30: Inspection and mainte-nance; January 1995

DIN 1986-32 Drainage and sewerage systems for buildings and plots of land; Part 32: Backflow gates for non-faecal sewage; Inspection and maintenance; June 1986 DIN 1986-33 Drainage and sewerage systems for buildings and plots of land; Part 33: Backflow gates for fae-cal sewage; Inspection and maintenance; Octo-ber 1987 DIN 1986-100 Entwässerungsanlagen für Gebäude und Grund-stücke [Drainage and sewerage systems for buildings and plots of land; Part 100: Additional provisions for EN 752 and EN 12056]; March 2002 DIN 1988-2 Drinking water supply systems; materials, com-ponents, appliances, design and installation (DVGW Code of practice); December 1988 EN 476 General requirements for components used in discharge pipes, drains and sewers for gravity systems; 1997 EN 752 Drain and sewers systems outside buildings EN 805 Water supply – Requirements for systems and components outside buildings; 2000 EN 1091 Vacuum sewerage systems outside buildings; 1996 EN 1610 Construction and testing of drains and sewers; 1997 DIN EN 1610 Beiblatt 1 [Supplement 1] Verlegung und Prüfung von Abwasserleitungen und -kanälen – Verzeichnis einschlägiger Nor-men und Richtlinien [Construction and testing of drains and sewers – Index of relevant standard specifications and directives]; 1997 EN 12056-1 Gravity drainage systems; Part 1: General and performance requirements; 2000

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EN 12056-2 Gravity drainage systems; Part 2: Wastewater systems, planning and calculation; 2000 EN 12056-3 Gravity drainage systems; Part 3: Roof drainage, planning and dimensioning; 2000 EN 12056-4 Gravity drainage systems; Part 4: Wastewater lift-ing installations; planning and dimensioning; 2000 EN 12056-5 Gravity drainage systems; Part 5: Installation and testing, instructions for operation, maintenance and usage; 2000 EN 12889 Trenchless construction and testing of drains and sewers; 2000 EN ISO 9001 Quality management systems – Requirements; 2000 RAL-GZ 961 Herstellung und Instandhaltung von Abwasserlei-tungen und -kanälen – Gütesicherung [Producti-on and maintenance of sewers and drains – Qua-lity assurance]; April 2002

4.2.2 ATV-DVWK Rules and Standards

ATV-DVWK-A 127E Static Calculation of Sewers and Drains; August 2000 ATV-A 128E Standards for the Dimensioning and Design of Stormwater Structures in Combined Wastewater Sewers; April 1992 ATV-DVWK-A 139E Installation and Testing of Drains and Sewers; June 2001 ATV-A 140E Rules for the Operation of Sewers; Part 1: The Sewer Network; March 1990

ATV-A 148E Service and Operating Instructions for Personnel of wastewater Pumping Stations, Wastewater Pressure Pipelines and Stormwater Tanks (Guide to the Formulation of an Instruction); March 1994 ATV-DVWK-A 156 Regeln für den Kanalbetrieb – Regenbecken und –entlastungen [Rules for the Operation of Sewers – Stormwater Tanks and Overflows]; November 2000 ATV-DVWK-A 157E Sewer System Structures; November 2000 ATV-M 101E Planning of Drain and Sewer Systems, New Con-struction, Rehabilitation and Replacement; May 1996 ATV-M 143E-1 Inspection, Repair, Rehabilitation and RepIace-ment of Sewers and Drains; Part 1: Principles; December 1989 ATV-M 143E-2 Inspection, Repair, Rehabilitation and RepIace-ment of Sewers and Drains; Part 2: Optical In-spection; April 1999 ATV-M 143E-6 Inspection, Repair, Rehabilitation and RepIace-ment of Sewers and Drains; Part 6: Leak Testing of Existing, Earth Covered Sewers and Drains and Shafts Using Water, Air Overpressure and Vacuum; June 1998 ATV-M 146E Implementation Examples for ATV-Standard A 142E Sewers and Drains in Water catchment Ar-eas; April 1995

4.2.3 DVGW / LAWA Rules and Standards

DVGW W 101 Richtlinien für Trinkwasserschutzgebiete; I. Teil: Schutzgebiete für Grundwasser; [Standards for Drinking Water Protective Zones; Part I: Protecti-ve Zones for Groundwater] February 1995 DVGW W 102 Richtlinien für Trinkwasserschutzgebiete; II. Teil: Schutzgebiete für Talsperren [Standards for Drin-king Water Protective Zones; Part II: Protective Zones for Barrier Reservoirs]; April 2002

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DVGW W 403 Planungsregeln für Wasserleitungen und Was-serrohrnetze [Planning Rules for Water Pipelines and Water Networks]; January 1988

LAWA Richtlinien für Heilquellenschutzgebiete [Stan-dards for Protective Zones of Medicinal Springs]; January 1998