Water Supply - Fifth edition

By Alan C. Twort, Don D. Ratnayaka and Malcolm J. Brandt: Co-published by Arnold Publishing, 338 Euston Road, London NW1 3BH and IWA Publishing Alliance House, 12 Caxton Street, London SW1H 0QS, UK: 2000: ISBN 0-340-72018-2: 250 x 175mm: xii + 676pp: Hardback: £55

In the day of yore, every water engineer's bookshelf contained a copy of the Manual of British Water Engineering Practice (published by the Institution of Water Engineers, one of CIWEM's forerunners) and a copy of 'Twort'. Although the two books covered many of the same topics it was always felt a good idea to have both. The first edition of the IWE book was published in 1950 (my copy is the Fourth edition dating from 1969) and has since been replaced by a number of CIWEM publications.

The first edition of Water Supply was written by Alan Twort and published in 1963. Changing standards in water engineering practice and the regulatory requirements meant that it was necessary for the book to be revised every ten years or so. This latest edition follows on only six-years from the publication of the fourth edition, reflecting the increasing pace of change in water engineering and regulation requirements.

The fifth edition has involved a substantial re-writing of the book, although without loosing the essential flavour of earlier versions. In addition to the three principal authors, there are ten contributing authors who, with one exception, work at a senior level for consultants Binnie, Black and Veatch. The tenth contributor is from the Drinking Water Inspectorate. In addition, half a dozen other specialists from BBV acted as reviewers and advisors, with nine further advisors from a variety of different organizations. Many readers may feel a little saddened as I do, that Frank Law, a principal author from earlier editions, is now only an advisor.

The subjects covered in the book are organized into 15 chapters that are in a more-or-less unchanged order from previous editions, although the overall content has increased by an estimated 30%. The first chapter tackles the difficulties in estimating how much water is required in public supplies, and includes reference to a number of relatively recent surveys. It discusses the accuracy of water meters with a useful table relating accuracy to the type of meter and flow rates. Other topics covered include leakage (or unaccounted for water), and the effects of metering on consumption.

Chapter 2 describes the organization and financing of public water supplies, principally in the UK, with brief information on the USA and a few international comparisons. Did you know for example, that there are five-times the number of waterworks employees per connection in China than in the England? A description of the functions of the Director General and the Environment Agency are included together with an outline of the water supply and regulatory bodies in Scotland and Northern Ireland. Reference to the UK Environment Agency in the contents list is confusing however, as the Agency only has remit in England and Wales. Happily, this error is not repeated in the text.

The following three chapters are where the only fundamental restructuring of the book has occurred. Essentially, the new book separates hydrology and surface water supplies, from groundwater supplies and from dams and river intake structures. Chapter 3 covers the subjects of hydrology and water supplies based on surface water abstractions. The first part of the chapter covers hydrological measurements and theory and the second part describes the estimation of yield. Chapter 4 is devoted to all aspects of water supplies based on groundwater, with Chapter 5 covering dams and river intakes. All contain useful information. I was a little disappointed however, about the level of detail on pumping tests in Chapter 5, and the omission of a full reference to the British Standard Code of Practice on Pumping Tests (BS 6316).

Chapter 6 covers the all aspects of water quality - chemical, biological and microbiological - in relation to UK standards and other regulators in the EU, WHO and USA. A useful new section covers new and emerging issues concerned with industrial pollution, and microbial and viral contaminants.

Having described water quality problems, Chapter 7 explains water storage and primary water treatment by screening and filtration. The level of detail includes the removal of cryptosporidium oocysts and giardia cysts. More advance forms of water treatment such as softening, iron and manganese removal and membrane technology are covered in Chapter 8, with the important area of disinfection given the whole of Chapter 9.

The following six chapters are concerned with the fundamental water engineering topics of hydraulics, service reservoirs, pumps, pipes and distribution systems and operational aspects of water distribution.

All the chapters have a list of references appropriate to the subject matter. Any general textbook has its limitations, and its value is enhanced by pointing the enquiring reader to sources of more detailed information. Most of the reference lists are extensive although some include dated texts and omit some important more recent ones. A reference work of value also needs to be reader-friendly with a well-planned index. In this case, the index covers almost eight pages, a reasonable size for a large textbook, although there is some room for improvement. I could not easily find a reference to pumping tests for example, and only tracked it down by looking for boreholes and then being referred to wells and boreholes finally to find testing.

Overall, I am impressed with the authors' achievement in improving this a standard textbook without loosing its original character, despite it being written by a large team. They have kept 'Twort' as a handy reference book that I am pleased to have on my shelf. A significant part is the way that the style, the form of the illustrations and the presentation of the book have been kept the same as before, with, no doubt, some credit for this achievement also due to the publishers.

This review appeared in the Journal of the Chartered Institution of Water and Environmental Management 2002, Volume 16, No 1, page 76.

Copyright © CIWEM 2002