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PREFACE

Design of water treatment plants is evolving. New technologies and unit processes con-
tinue to emerge and have become much more common since publication of the third edi-
tion of Water Treatment Plant Design 7 years ago. Security issues, summarized in a new
chapter in this fourth edition, have forever redirected many aspects of design. Additional
reference materials for security design considerations are becoming available and should
be consulted for further information.
Equipment design continues to broaden, yet sources of manufactured products have
become more consolidated in the past 7 years. This new edition contains numerous revi-
sions of illustrations and photography; however, not all new technologies or equipment
offerings are represented. The American Water Works Association (AWWA) and the
American Society of Civil Engineers (ASCE) are interested in obtaining input from read-
ers on how to facilitate the future exchange of information on equipment. Alternatives
such as Web-based links are being considered to better provide needed product informa-
tion to the design community.
The first version of Water Treatment Plant Design was published in 1939 as a man-
ual of engineering practice for the ASCE. In 1969, the manual assumed book form and
was updated to include a discussion of developments in pretreatment and filtration pro-
cesses. The 1969 edition was the result of a joint effort between committees of the ASCE,
the AWWA, and the Conference of State Sanitary Engineers (CSSE).
The second edition was produced in 1990 through a joint effort of the AWWA and
the ASCE. The material for each chapter was prepared by one or more authors and re-
viewed by a joint committee of AWWA and ASCE members.
The third edition, published in 1998, was a joint AWWA and ASCE effort and was
essentially a complete rewrite of the previous edition. The information presented in the
book was prepared as a guide and represented a consensus of opinion of recognized au-
thorities in the field. A steering committee made up of members from both associations
guided the revision process.
Updates to this fourth edition provide significant new information on many important
topics. Authors from engineering firms and water utilities throughout North America have
revised the chapters and written the two new chapters on UV technologies and security.
Providing support to the chapter authors was a significant base of volunteer reviewers.
Due to the ability of the authors to distribute drafts of their chapters electronically to large
numbers of prospective reviewers, it became apparent that the attempt to accurately name
all reviewers would result in inadvertent omissions. Therefore a general acknowledgment
and thanks to all reviewers is hereby offered.
Guiding the development of the entire fourth edition was a dedicated joint
AWWA/ASCE steering committee. The members of this committee were

C. Michael Elliott (Chair), Steams & Wheler, LLC
Bruce E. Burris, HDR Engineering, Inc.
Anthony J. Geiss, Jr., Onondaga County Water Authority

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