A Review of “Algae: Source to Treatment (M57)”

This algal management manual has been in preparation for multiple years and is now available to support drinking water supply operations that experience problems relating to algae. It has no stated author, but a steering committee of 7 commissioned chapters from 32 authors, which were reviewed by a team of 8. The manual provides a remarkably detailed treatment of algal assessment, taxonomy, and management for potable water supplies. This 480-page, durable soft cover volume is expensive, but compared to the cost of addressing algal problems, it is well worth the price.

Organized into 3 sections (Methods, Organisms and Management) the manual covers the range of approaches to assessing algae in water supplies, the types of algae that may be encountered, and how to minimize issues for consumers. It is logically arranged, packed with information, and generally well written. The methods section is fairly complete, including old standard approaches such as microscopic analysis and newer techniques such as luminescent probes. Discussion of advantages and disadvantages of each option is clear and insightful. A framework for fitting solutions to problems in algal assessment is provided. As a guide to alternatives for evaluating algae in water supplies, this section meets its goals.

A chapter on algal toxin assessment is well done. Likewise, algal pigments are explained well, as are options for measurement, interpretation of results, and the limitations of each approach. Information on algal biomass in relation to nutrient supply and light is also covered in an informative manner. The message that increased nutrient supply leads to increased algal densities and a shift toward more cyanobacteria is made very clear, and is a message that needs to be delivered to the water supply industry. Yet the lack of reliable correlation between increasing algae and algal toxin concentration is also properly expressed, with excellent coverage of the many factors that complicate such relationships. The education value of this section is high, and consultants working with water suppliers should recommend it to their clients.

The section on organisms is organized into chapters on each defined algal group, each written by one or more authors, apparently with little guidance on format and content. The chapters are informative, but uneven in coverage. The pictures are helpful, although lack of scale bars and small size in some cases constrains use in actual identification exercises. Cyanobacteria and green algae, the most important algae in the vast majority of water supplies, each get chapters of 20 pages. The information provided is extremely useful, but there was apparently not space to cover all that would be of use to water suppliers. Diatoms, also an important group but causing many fewer problems, are covered in 41 pages. Chrysophytes, a handful of which are important sources of taste and odor, are accorded 21 pages, and many algal divisions often lumped with Chyrsophyta have been covered in separate chapters. Haptophytes, which are implicated in some major toxicity events, were unfortunately omitted due to the untimely death of the planned author. Cryptophytes, which are virtually never a problem, get 15 pages and detailed electron micrographs and drawings, all exquisite but not very useful to a water supply lab technician trying to identify algae. Coverage should have been proportional to the magnitude and distribution of problems caused by identified algal groups. As a first effort to introduce water supply professionals to the spectrum of algae, this section is excellent, but it will not suffice for identification purposes, despite simple keys to major genera.

Ecological information is also uneven. The layout for the Xanthophyta and Phaeophyta is perhaps the most useful organizationally, but as stated in the section on significance of these algae to water supplies, they rarely matter. There is virtually no ecological information on the Euglenophyta or Dinophyta, which provide strong water quality indications in many cases. The ecological indications of diatoms, however, are very well covered, and the assimilation of much research on this topic is admirably done. Some ecological information is covered in the methods and management sections, suggesting little effort to meld the offerings by the many authors, but at least there are few inconsistencies. An index allows readers to track down topics of interest by keywords. There is also a glossary, but it has less than half the important technical terms used in the manual and appears to have many terms not used in the manual; it was a good idea that falls short of satisfying the need.

The management section contains a wealth of useful information and is a solid introduction to methods of algal control in source water and treatment facilities. As with the taxonomic section, the information presented is informative; it is just not complete. Published in 2010, there are almost no references more recent than 2007, suggesting a lengthy delay in the layout and printing phase. Yet a lot has happened in the interim, and even techniques that were well known prior to 2007 are inadequately covered. The discussion of source water management methods is basically a rehash from other books, the most recent of which is the highly regarded Cooke et al. 2005. Yet there is no mention of aeration or mixing as algae management techniques, and for those techniques that are covered, a lot of helpful detail was lost in boiling the presentation down to a manageable level. Still, as an introduction to options, this section provides a solid basis for initiating an evaluation of management strategies.

Included in the management section is a chapter on taste and odor that by itself is worth the publication price. Tables of taste and odor compounds with associated smells, taste, and odor producers, odor thresholds, and even approximate cell counts that yield taste and odor for specific algal genera represent an assimilation of data that I have never seen elsewhere and will be of immediate and outstanding use to water suppliers facing this most common of source water problems. The following chapter on control of cyanotoxins is also very helpful and provides essential background for choosing a control strategy for this health concern.

I have been critical of many aspects of this publication because I work extensively with drinking water suppliers with algae problems and know how much a comprehensive resource on this topic is needed. However, this book comes much closer to being that resource than anything I have seen published to date, and any shortcomings are omissions, not erroneous or inappropriate inclusions. Page limits undoubtedly constrained the effort to meet the rather ambitious goal of the title, and more coordination among contributing authors might have enhanced presentation, but I would readily recommend this publication to any water supply organization and to many recreational lake managers as well.