GERMAN ATV-DVWK RULES AND STANDARDS

Similar documents
GERMAN ATV-DVWK RULES AND STANDARDS. STANDARD ATV-DVWK-A 157E Sewer System Structures

Advisory Leaflet DWA-M 180E

GERMAN ATV-DVWK RULES AND STANDARDS

GERMAN ATV-DVWK-RULES AND STANDARDS

DWA Rules and Standards

DWA- Topics. Corporate-Metric Benchmarking as Component of the Modernisation Strategy - Performance Indicators and Evaluation Principles

GERMAN DWA Rules and Standards. plus further publications and information English Version

en.dwa.de Clear Concepts. Clean Environment. DWA Set of Rules plus further publications and information English Version April 2016

Set of Rules. German DWA. Advisory Guideline DWA-M 144-3E

GERMAN ATV-DVWK RULES AND STANDARDS. STANDARD ATV-DVWK-A 281E Dimensioning of Trickling Filters and Rotating Biological Contactors

DWA Set of Rules. Standard DWA-A 262E. en.dwa.de

Standards for the Dimensioning and Design of Stormwater Structures in Combined Sewers

GERMAN ATV-DVWK-RULES AND STANDARDS

DWA Rules and Standards

Dredged Material Treatment and Disposal Facilities

Set of Rules. German DWA. Advisory Guideline DWA-M 386E. Thermal Treatment of Sewage Slugde Mono-Incineration. December 2011

DWA Set of Rules. Standard DWA-A 216E. en.dwa.de. Energy Check and Energy Analysis Instruments to Optimise the Energy Usage of Wastewater Systems

Set of Rules. German DWA. Advisory Guideline DWA-M 114E. Energy from Wastewater Thermal and Potential Energy. June 2009

Fit in Wastewater Technology?

Dredging for Climate Change and Transport in the Netherlands

CHANGE OF AN OLD NAVY BASE TO A MODERN MARINA IN BOLTENHAGEN (BALTIC SEA)

DWA- Topics. Anthropogenic Trace Pollutants in the Water Cycle. Pharmaceuticals

CTB3300WCx Introduction to Water and Climate

European sediment regulations: Gaps and bridges

6. Croatian Forum. Sustainable Construction ZAGREB

European Sediments 1

International cooperation for transboundary water pollution control:

Dredged Material Management in Hamburg

PIANC Commission Working Group Report Reviews

DOORNVALLEI EXT 5 & 6

Investigation, remediation, and environmental development in port areas

Legal Basis of Water Management in Austria

Handling of Dredged Material in the Netherlands H.P. Laboyrie M.Sc. Eng (C.E. Delft)

U l t i m a t e e f f i c i e n c y D re D ging

Workshop Summary: Finding solutions to groundwater flooding Transnational exchange on governance challenges

ENVIRONMENTAL IMPACT ASSESSMENT (BASIC ASSESSMENT) PROCESS: PROPOSED REVERSE OSMOSIS PLANT, IRON ORE HANDLING FACILITY, PORT OF SALDANHA

Remediation as a Contribution for a sustainable Sediment Management in the River Rhine

Order of road works and servicing construction to be carried out in accordance with the staged contract construction sequence specified below.

Harbour developments and its. Increasing scientific efforts. effects on ecological functioning. parallel. and structures

BAW Letter No. 2 May 2006

C. Foundation stabilization for pipe and utility structures.

Sand extraction Maasvlakte 2 Project: License, Environmental Impact Assessment and Monitoring.

Created by Simpo PDF Creator Pro (unregistered version) Asst.Prof.Dr. Jaafar S. Maatooq

HYDRAULICS DIVISION. Assoc. Prof. Dr. Mustafa ERGİL. Assoc. Prof. Dr. Umut TÜRKER

Temporary Watercourse Crossing: Culverts

TABLE OF CONTENTS LEGAL NOTICE

Properly constructing and maintaining a road drainage system is the most effective ways to reduce flood damage

An NGO view on the challenges of policy integration

The new Lauenburg lock

WELCOME QUESTIONS

New York- New Jersey Harbor Estuary. Lower Passaic River

The World of. Let s fix this. Clean, safe and well-functioning waters. Restoring Lake Fúquene. smart solution for hard work.

Jim Bridger Power Plant

Part III will be filled out by all applicants applying for a permit to perform dredging.

Ottumwa Generating Station Project No Closure Plan for Existing CCR Revision: 0 Surface Impoundments TABLE OF CONTENTS

PROPOSED PLAN FOR CLEANING UP THE LOWER 8 MILES OF THE LOWER PASSAIC RIVER

Harbour Constructions

The Construction of JadeWeserPort A Deepwater Container Terminal in Wilhelmshaven

CHAPTER 13 Environmental Guidelines for GENERAL CONSTRUCTION PRACTICES

EVALUATION - SECTION 404 OF THE CLEAN WATER ACT DISCHARGE OF SEDIMENTS FROM OR THROUGH A DAM

The planned conversion of part of the Port of

Implementation Plan and FAQs for the Guide to Water Act Authorizations Required for Dugouts, Borrow Pits and other types of Pits/Excavations

Environmental Engineering-I

Wellhead Protection Issues Related to Mining Activities Minnesota Rural Water Conference March 4, 2014

SNOW REMOVAL & DISPOSAL POLICY

Suggestions for Guideline on Borrow Pits for Water Ponds in Mozambique

Environmental Assessment Appendix H: Section 404(b)(1) Guidelines Evaluation. U.S. Army Corps of Engineers New York District

Building Better Storm Water Quality

Hudson River PCBs Superfund Site

Checklists for surveying and assessing industrial plant handling materials and substances, which are hazardous to water

Geotechnical aspects of landfill design

Application of Mulch Biowall for Anaerobic Treatment of Perchlorate in Shallow Groundwater

Water Quality in Cleveland Bay. Frequently Asked Questions

HYDRAULIC ENGINEERING

Evaluation report for Odoriferous Substances

Appendix 8: Best Practicable Environmental Option (BPEO) Assessment

Irrigation Structures 1

SECTION EROSION AND SEDIMENTATION CONTROLS

WE GET HEAVY WEIGHTS MOVING WHATEVER THEIR SHAPE OR SIZE.

SEDIMENT CHOREOGRAPHY

Advanced Enviro-Septic TM Basic Design and Installation Manual

European Water and Sanitation Services vs. Sustainable Development Example Germany. ATHENS European Week, Autumn 2013 Paris, November 19 th, 2013

How Phosphate is Mined and Processed

Integrated River Engineering Project. Catalogue of Measures. for the Danube to the East of Vienna

Conference Paper The increasing role of water management in the Dutch planning system

Profile of the German Water Sector 2011 Summary

Issues Options and Strategies for Flood Management : Shifts in approaches for flood Management in Bangladesh

Side channels along the River Rhine in the Netherlands; an effective rehabilitation measure?

Conditions Annexed to and Forming Part of Land Use Permit # MV2013C0021

CHAPTER 4 - EROSION & SEDIMENT CONTROL AND STORMWATER MANAGEMENT ORDINANCE OF DUBUQUE COUNTY, IOWA. Adopted March 29, 2010.

Assessment Schedule 2013 Agricultural and Horticultural Science: Analyse a New Zealand primary production environmental issue (91532)

Florida Department of Environmental Protection. Bureau of Mining and Minerals Regulation. Regulation of Mines. Howard J. Hayes, Program Administrator

The Environmental Perspective of the Rhine

PLAN SHEET INDEX TYPICAL ARCHITECTURAL DETAILS - WINDOW SCHEDULE AND DETAILS

City of Brandon Division 2 Standard Construction Specifications Section January 2007(Revision 1) Page 1 of 8 ROADWAY EXCAVATION AND GRADING

Wetland Permit Application

WASTEWATER TREATMENT DURING TUNNEL CONSTRUCTION ON BUREAU OF RECLAMATION PROJECTS. By Dr. John C. Peters* INTRODUCTION

Chapter 6 Objective: Protect and Enhance the Environment

b. Projects Without PED Agreements. Credit for PED Coordination Team activities will be provided under the following criteria:

Hydraulic engineering

Transcription:

GERMAN ATV-DVWK RULES AND STANDARDS ADVISORY LEAFLET ATV-DVWK-M 362-2E Handling of Dredged Material Part 2: Case Studies October 2004

GERMAN ATV-DVWK RULES AND STANDARDS ADVISORY LEAFLET ATV-DVWK-M 362-2E Handling of Dredged Material Part 2: Case Studies October 2004 Publisher/Marketing: Deutsche Vereinigung für Wasserwirtschaft, Abwasser und Abfall e.v. German Association for Water, Wastewater and Waste Theodor-Heuss-Allee 17 53773 Hennef Germany Tel.: +49 2242 872-333 Fax: +49 2242 872-100 E-Mail: kundenzentrum@dwa.de Internet: www.dwa.de

The German Association for Water, Wastewater and Waste, DWA (former ATV-DVWK), is the spokesman in Germany for all universal questions on water and is involved intensely with the development of reliable 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 DWA 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. 14,000 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 updating 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. Imprint Publisher and marketing: DWA German Association for Water, Wastewater and Waste Theodor-Heuss-Allee 17 53773 Hennef, Germany Tel.: Fax: E-Mail: Internet: +49 2242 872-333 +49 2242 872-100 kundenzentrum@dwa.de www.dwa.de Translation: Barbara Bokeloh, Rheinbreitbach Printing (English version): DWA ISBN-13: 978-3-940173-45-4 The translation was sponsored by the German Federal Environmental Foundation (DBU). Printed on 100 % recycling paper DWA Deutsche Vereinigung für Wasserwirtschaft, Abwasser und Abfall e.v., Hennef 2008 German Association for Water, Wastewater and Waste All rights, in particular those of translation into other languages, are reserved. No part of this Advisory Leaflet 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. October 2004 2

Foreword Subject of this Advisory Leaflet is dredged material obtained from the maintenance and development of inland water bodies up to the freshwater border. This procedure generally can also be applied to the entire coast region. The volume of dredged material occurring in the Federal States and municipalities has been estimated by company LAHMEYER INTERNATIONAL (1997) who carried out a survey on behalf of the Umweltbundesamt (UBA Federal Environment Office of Germany) between 8 mio. m³ and 10 mio. m³ annually. Additionally, there are between 2 mio. m³ and 3 mio. m³ from the river and navigation authority (WSV Wasser- und Schifffahrtsverwaltung). Not accounted for have been the volumes which occur in single expansion activities like the development of the project 17 Incorporation of Berlin in the West German canal system of the Transport Projects German unity. The pollution load of dredged material in the case studies described herein, in many cases is assessed according to the Technical Standards No. 20 of the Laenderarbeitsgemeinschaft Abfall [LAGA Working Group on Waste of the Federal States of the Federal Republic of Germany] Anforderungen an die stoffliche Verwertung von mineralischen Reststoffen/Abfällen Requirements to the material recycling of mineral residues/waste (Residue Directive) of 1997 and graded under classification code (Z). The Advisory Leaflet ATV-M 362 Handling of dredged material, parts 1, 2 and 3 was first prepared in 1997/99 by the ATV-Technical Committee 3.7 Baggergut aus der Gewässerbehandlung [dredged material from water treatment]. A new and changed legal basis and additional standards as well as improved technical implementations have necessitated an updating of this paper. The revised part 2 of the Advisory Leaflet focuses on case studies. As far as possible, the legal classification and relevant standards and approval procedures applicable at the time each case study was realized have been mentioned for the cases presented. However, current procedures which copy appropriate case studies must adhere to actual legal regulations. Part 1 of the Advisory Leaflet ATV-M 362 Handling of dredged material is presently being revised and outlines the estimation of the different utilization possibilities, the basic storage feasibilities and the currently valid legal standards. Part 3 of this Advisory Leaflet, Umgang mit Baggergut Mindestuntersuchungsprogramm [Handling of dredged material minimum investigation programme] deals with the programme of the minimum scope of studies and was published in 1999. Authors This Advisory Leaflet has been prepared by the ATV-DVWK-Fachausschuss AK-7 Baggergut aus der Gewaesserbehandlung [ATV-DVWK Technical Committee AK-7 Dredged material from water treatment ]. The ATV-DVWK-Technical Committee is formed by the following members: BAER, Eckart BAUM, Annett BERTSCH, Wolfmar DETZNER, Heinz-Dieter FECHTER, Leonhard HERRMANN, Llienhard HUCK, Sabine SCHEIER, Michael SCHRADER, Heinz Dipl.-Biol., Roesrath Dipl.-Ing., Hennef Dr., Simmern (WW) Dipl.-Ing., Hamburg Dr.-Ing., Berlin Dr.-Ing., Berlin (Obmann) Dipl.-Geol., Berlin RA M., Koeln Dipl.-Ing., Porta-Westfalica Authors of technical contributions, who are not members of the Technical Committee, will be named as originator of their contributions. October 2004 3

Contents Foreword... 3 Authors... 3 User Notes... 7 Scope... 7 Case Studies... 8 1 Avoiding, Relocation, Immediate Use... 8 1.1 Avoidance/Reduction of Dredged Material... 8 1.2 Avoidance of Dredged Material/Sedimentary Deposit in Water Bodies Current Deflection Wall... 8 1.3 Relocation in the Water Body... 10 1.4 Immediate Use in the Water Body Storage of Dredged Material in Gravel Pits... 12 1.5 Airbus-Extension Area Muehlenberger Loch, Hamburg (Germany)... 14 1.6 Harbour Dredging and Relocation of Sediments in the Lake Starnberg... 17 2 Storage in the Water Body... 19 2.1 Backfilling of the Rogaetz Gravel Pit, North of Magdeburg... 19 2.2 Storage in Separated Parts of the Water Body Lake Hengstey, Essen... 21 2.3 Backfilling Harbour Basins in Luebeck... 22 2.4 Backfilling Harbour Basins of the "Rodewisch Hafen", Hamburg... 23 2.5 Underwater Deposit Slufter, Rotterdam... 25 2.6 IJsseloog Project (Lake Ketelmeer, The Netherlands)... 28 3 Storage on Land and on Flushing Fields... 29 3.1 Feasibility Study on Depositing Dredged Material on the Hesselte Deposit at the Dortmund-Ems-Canal (DEK)... 29 3.2 Storage of Dredged Material on Flushing Fields... 31 3.2.1 General Facts on the Storage of Dredged Material on Flushing Fields... 32 3.2.2 Management of Flushing Fields in the Region of the Town of Rostock... 33 3.2.3 Lake Harkort/Ruhr River/NRW [North Rhine Westphalia]... 37 3.3 "Dry Accommodation in the Flushing Field Drigge, Isle of Ruegen... 39 3.4 Dewatering Fields in Hamburg-Moorburg... 41 4 Sludge Removal and Conditioning... 43 4.1 Programme System Description for the Conditioning of Contaminated Dredged Material, Mud, Soil and Harbour Excavation Material According to HELALIM -Bio-Polder Procedure. 43 4.2 Case Studies on the Treatment of Dredged Material According to the HELALIM - Bio-Polder Procedure... 46 4.2.1 Teltow Canal... 46 4.2.2 Bay Rummelsburg, Berlin... 47 4.2.3 Sludge Removal in Lake Lietzen... 49 4.2.4 Sludge Removal from the Storm-Water Retention Tank North, Berlin... 49 4.3 Further Case Studies on Sludge Removal... 51 4.3.1 Sludge Removal in the Low Weir Upstream of the Reservoir Malter and Utilization for Stockpile Recultivation... 51 4.3.2 Sediment Clearance in the Storage Reservoir Radeburg I Restoration of Flushing Field... 52 4.3.3 Sludge Removal in Reservoir for Drinking Water in Saxony and Re-use of Sediments... 53 October 2004 4

4.4 Sludge Removal in Lakes of North Rhine Westphalia... 55 4.4.1 Use as Dump Site Cover "Windmuehlenbruch/Nette"... 55 4.4.2 Use in Gravel Pit Recultivation Lake Breyel/Nette/NRW [North Rhine Westphalia]... 56 4.4.3 Sludge Removal in Fish Fonds in NRW [North Rhine Westphalia]... 57 4.4.4 Sediment Clearance in the Low Weir Oehna (Reservoir Bautzen)... 58 5 Conditioning and Integration... 60 5.1 Grain Size Classification METHA and Dewatering... 60 5.2 Conditioning by Integrating Fine Grain... 62 5.2.1 Incorporation of Fine Grain in the Manufacture of Bricks... 62 5.2.2 Integration of Fine Grain in the Manufacture of Expanded Clay Pellets... 63 5.3 Harbours of Magdeburg... 64 6 Disposal... 65 6.1 Treatment and Disposal on the Bremen-Seehausen Deposit... 65 6.2 Land Disposal of Sized Dredged Material on the Areas Francop and Feldhofe... 68 6.3 Storage on the Dump for Construction Site Rubble in Deetz... 70 7 Examples from Related Fields... 73 7.1 Ecological Soil Management Hannover-Kronsberg... 73 7.2 Soil Cleaning... 76 8 Summary... 78 Literature... 79 Reference Sources... 83 List of Pictures Figure 1.2-1: Principle of the effect of a current deflection wall with river bed waves... 9 Figure 1.2-2: Basic construction of a current deflection wall... 10 Figure 1.3-1: Schematic diagram of an automotive dredger s mud barge MC 40... 12 Figure 1.4-1: Hydrogeological section of a gravel pit... 14 Figure 1.4-2: Gravel pit has been sealed by suitable graining... 14 Figure 1.5-1: Half a year after start of construction: flood protection of the enclosing embankment has been achieved... 16 Figure 1.5-2: A year after start of construction... 16 Figure 1.5-3: One and a half year after start of construction... 17 Figure 2.1-1: Location of the Rogaetz gravel pit on the Elb river near Magdeburg... 21 Figure 2.2-1: Dredging of Lake Hengstey flushing fields 1-3... 22 Figure 2.3-1: Diagrammatic view of the vacuum-compaction... 23 Figure 2.4-1: Aerial photograph of Rodewisch Hafen... 24 Figure 2.4-2: Schematic diagram of the surface elevation Rodewisch Hafen... 24 Figure 2.5-1: Development forms of sub-aquatic deposits on land and in open water... 26 Figure 2.5-2: Schematic diagram of an erosion-safe deposit... 27 Figure 2.5-3: Aerial photograph of the dredged material deposit de Slufter before Rotterdam... 27 Figure 2.6-1: Aerial photograph of the IJsseloog-Deposit, Lake Ketelmeer... 28 Figure 2.6-2: Basic layout of the IJsseloog-Deposit, Lake Ketelmeer... 29 October 2004 5

Figure 3.2.2-1: Hydraulic filling of dredged material in a longitudinal flow sizing polder of the flushing field Schnatermann... 34 Figure 3.2.2-2: Aerial photograph of the flushing field complex Radelsee of the IAA Rostock with the two longitudinal flow polders on the left and the maturing beds on the right hand side of the picture... 35 Figure 3.2.2-3: Mixed soil arranged as clamps (sand/mud compositions) in the maturing plant Radelsee... 36 Figure 3.2.2-4: Spreading matured dredged material on arable land for soil improvement... 37 Figure 3.2.3-1: Re-storing dredged material from Lake Harkort by means of hydraulic filling... 38 Figure 3.3-1: Position of the flushing field Drigge at the Strait of Strela... 40 Figure 3.3-2: Sampling well at the flushing field before hydraulic filling... 41 Figure 3.4-1: Dewatering fields Moorburg Centre... 42 Figure 3.4-2: Basic layout of a dewatering field facility... 43 Figure 4.1-1: Schematic structure of bio-polders/helalim -bed... 44 Figure 4.1-2: General view of the bio-polder plant in Skaby, summer, 2000... 44 Figure 4.2.2-1: Bay Rummelsburg, Berlin, with incorporated sheet piling... 48 Figure 4.2.2-2: Lake Rummelsburg, sediment treatment by filling in particular iron oxide-hydrate and calcium nitrate... 48 Fiugre 4.3.1-1: Distribution of grain sizes of sediments in the low weir Malter, results of two samples... 52 Figure 4.3.2-1: Selection of sediments in the flushing field by means of bulldozer and dredger... 54 Figure 4.4.1-1: Shallow lake Windmuehlenbruch/Nette at the beginning of the sludge removal... 55 Figure 4.4.2-1: Sludge removal in lakes by means of a suction vessel... 56 Fiugre 5.1-1: METHA treatment plant for dredged material... 61 Figure 6.1-1: Diagrammatic view of the process Integrierten Baggergutentsorgung Bremen- Seehausen [ Integrated disposal of dredged material in Bremen Seehausen ]... 67 Figure 6.2-1: Diagrammatic profile of the silt deposit Feldhofe... 69 Figure 6.2-2: Placing principle of the layers of silt to be stored... 69 Fiugre 6.2-3: View of the silt deposit in the year 2015 Impression of an artist... 70 Figure 7.1-1: Northern viewpoint... 74 Fiugre 7.1-2: Accommodation of soil material in Kronsberg... 75 Figure 7.2-1: Process steps of soil cleaning... 77 List of Tables Table 4.1-1: Composition of pollutants which can be biodegraded or eluted in the bio-polder plant... 45 Table 4.2.1-1: Mean pollutant concentration before and after treatment in the HELALIM -bed... 47 Table 4.2.2-1: Mean pollutant concentration before and during treatment in the bio-polder plant Skaby... 49 Table 4.2.3-1: Mean pollutant concentration in sediments at the Massante Bridge (Berlin) before and after treatment in the bio-polder plant... 50 Table 4.2.4-1: Mean pollutant concentration in sediments of the storm-water retention tank North (Berlin) before and after treatment in the bio-polder plant... 50 Table 4.3.1-1: Pollutant concentrations in sediments in the low weir upstream of the reservoir Malter... 51 Table 4.3.2-1: Classifying eluate concentrations of sediments of the flushing field Radeburg I... 53 Table 6.3-1: Classification criteria in supplement to the parameters of dump category I (AbfAblV) for the Deetz dump for construction site rubble... 72 October 2004 6

User Notes This Advisory Leaflet is the result of honorary, technical-scientific/economic collaboration which has been achieved in accordance with the principles applicable therefore (statutes, rules of procedure of the ATV- DVWK and the Standard ATV-DVWK-A 400). For this, according to precedents, there exists an actual presumption that it is textually and technically correct. The application of this Advisory Leaflet is open to everyone. However, an obligation for application can arise from legal or administrative regulations, a contract or other legal reason. This Advisory Leaflet is an important, however, not the sole source of information for correct solutions. With its application 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 Advisory leaflet. Scope Part 2 of the Advisory Leaflet ATV-DVWK-M 362 Handling of dredged material is a demonstration of practised means to avoid, relocate, use, recycle and dispose of dredged material in case studies. The Advisory Leaflet is directed to the public, approving authorities and to all those in the Federal Republic, the Federal States and municipalities, who have to deal with the disposal of dredged material from the maintenance and development of water bodies. They are herewith provided with instructions for the handling of dredged material. Because of the complexity of the pollution load and different conditions on site, it will not be possible to apply a single and comprehensive procedure that covers all eventualities. The development therefore will always result in solutions for an individual case. The individual case studies or parts of them have to be understood as modules, which, depending on the problem (or purpose) and starting situation can be joined to new module-combinations, where ecological and economical aspects play an important role in the choice of approach to solve a problem. The compilation is not complete, and cannot be because of the manifold combination possibilities of the available modules, especially since new developments and new focal points have to be observed. Here, we would like to refer the reader to a publication of the Working Group I/17, the PIANC (1996). The second volume published at the end of 1997 (as CD-ROM), contains about 100 brief descriptions of suitable and available sampling, dredging, transportation, recycling and storage procedures for contaminated dredged material. Furthermore, approximately 20 international case studies on the storage of dredged material are documented in this publication. Die ATV-DVWK Working Group WW-2.5 Sedimentation removal from reservoirs has compiled an extensive work report entitled Sedimentation removal from reservoirs (ATV-DVWK 2004). Some case studies are also contained in the comprehensive compilation issued by CALMANO (2001). October 2004 7

Case Studies 1 Avoiding, Relocation, Immediate Use 1.1 Avoidance/Reduction of Dredged Material The legal dispute, whether dredged material is to be considered as waste, is to be taken from the Advisory Leaflet ATV-M 362-1. Wastes are to be avoided according to 4 para. 1 No. 1 KrW-/AbfG Waste Disposal Act. Hence, it is first to be examined whether dredged material can be avoided or minimized. At federal waterways in Germany, a general avoidance of dredged material within the frame of maintenance and development and in view of the transportation safety obligations is not possible under normal circumstances without effecting the national economy. In specific cases, however, the volume of dredged material can at least be reduced on a long-term basis, partly even avoided entirely by means of hydraulic measures. The most promising method of reducing the quantity could be a purposively planned dredging measure, which requires the dredging volume to first be defined and an exact adherence to the set standards when dredging, to avoid excess dredged volumes. A reduction of occurring dredged material can be achieved, if for example the entries to harbour basins or the setting of longitudinal walls would be arranged parallel to rivers. The design of groynes in hydraulic measures can contribute to the reduction of dredged material. To which extent the maintenance of water bodies of the Federal States or municipalities (drainage channels etc.) can be reduced, is generally difficult to answer. Dredging becomes immediately necessary when the runoff of water can no longer be guaranteed because flood retention basins or impoundments are filled with sediments. Dredged material is often aggregated alongside the water body (e. g. to the right and left hand side of a trench) to form an earth bank. However, in heavy rain there is the special danger that wet material may partly slide back into the water body. Environment-friendly dredging techniques There are a number of special dredging techniques available, which are differentiated by their hoisting capacity in respect of surface and depth, material density (portion of make-up water), turbidity and material loss during the dredging process. The dredging techniques therefore have to be examined (CEDA/IADA 1998) individually whether they are suitable in respect of their environmentfriendliness and efficiency depending on the condition of the dredged material A suitable precise technique will avoid an excess delivery of dredged material. This topic is treated by the IJsseloog project (see case study 2.6), VAN RAALTE (1997) and MINK (1997). 1.2 Avoidance of Dredged Material/Sedimentary Deposit in Water Bodies Current Deflection Wall method: design: assessment data: origin quantity soil characteristics chemical condition special criteria legal classification/standards: avoidance in the water body current deflection wall in the Hamburg Hafen eddies with increased sedimentary deposit reduction by 140,000 m³/a sand and silt, lightly argillaceous size related contamination of the fine grain similar to that of the actual suspended solids content nautical frame conditions are to be observed where applicable permission according to water legislation October 2004 8