Management of agricultural drainage water quality

Table of Contents

Edited by Chandra A. Madramootoo William R. Johnston and Lyman S. Willardson

Water Reports 13

INTERNATIONAL COMMISSION ON IRRIGATION AND DRAINAGE

FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS Rome, 1997

The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations or the International Commission on Irrigation and Drainage concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.

M-56
ISBN 92-5-104058-3

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© FAO 1997

This electronic document has been scanned using optical character recognition (OCR) software and careful manual recorrection. Even if the quality of digitalisation is high, the FAO declines all responsibility for any discrepancies that may exist between the present document and its original printed version.

Table of Contents

Preface

Acknowledgements

List of symbols, abbreviations and acronyms

Glossary of technical terms

Chapter 1 - Introduction

Need for artificial drainage
Agricultural, environmental and socio-economic benefits of drainage
Types of drainage systems

Surface drainage
Subsurface drainage
Secondary drainage treatments

Environmental impact assessment
Water quality issues
Drainage water management and disposal options

On-farm source control
Re-use of drainage water
Disposal and management of drainage water in closed basins
Water table management

Planning and designing drainage systems to protect and enhance water quality

Chapter 2 - Drainage water quality

Water quality characteristics

Pesticides
Toxic trace elements
Nutrients
Sediment
Bacteria
Temperature
Salinity and major ions
Sulphurous compounds

Protection of beneficial uses

Domestic and drinking water
Industrial supply
Agricultural supply
Aquatic life
Recreation

Chapter 3 - Water table management

General features

Water table control structures

Water quality benefits

Drainage hydrology and water quality
Nutrients
Pesticides

Operational aspects

Farm or catchment scale
Topography and soils

Monitoring requirements

Chapter 4 - Drainage water re-use

Re-use for crop irrigation

Effects of salinity on crop growth and yield
Agricultural management practices
Managing cycling and blending strategies

Re-use for saline agriculture and forestry

Concept of agriculture-forestry systems and solar evaporators
System design and planning

Re-use in a natural wetland

Re-use of surface drainage water
Re-use of subsurface drainage water

Chapter 5 - Drainage water treatment

Physical, chemical and biological treatment processes

Selection of treatment process
Methods of treatment
Physical/chemical treatment
Biological treatment
A treatment example

Treatment in constructed wetlands

Flow-through wetland functions
Planning and design of flow-through wetlands
Hydraulic and geohydraulic characteristics
Soils and geologic characteristics
Vegetative characteristics
Implementation, monitoring and management

Chapter 6 - Drainage water disposal

Disposal to natural hydrological systems
Land application and retirement
Evaporation ponds

Constructed evaporation ponds
Pond hydrology
Pond water chemistry and mineralogy
Pond biology and toxicity
Biological, chemical and physical treatment options

Deep well injection

Concept and technology
Environmental considerations
Geological considerations
Case study

Chapter 7 - Health issues related to drainage water management

The interactions between drainage, water management and health
Water related diseases and their vectors

Incidence of diseases - cases and mortality
Vector-borne diseases: transmission by insects
Water-based diseases: transmission by aquatic and semi-aquatic snails

Water-borne excreta related infections
Health risks and chemical pollution
Integrated control of transmission of vector-borne diseases

Components of integrated control approaches
Environmental management for vector control

Environmental management measures in drainage water management

Drainage water treatment, re-use and disposal
Environmental management measures applied to drainage structures

Development of control strategies

Chapter 8 - Institutional arrangements

Issues and problems

Objectives and interest groups
Need for regulation, conservation and communication
Role of public and private agencies and water users

Institutional mechanisms

Laws and regulations
Corporate organizations
Participatory planning
Incentives for water quality enhancement
Monitoring
Institutional capacity

References