improvised algal assays to meet their specific needs, but because they were 

 nonstandard, they offered no basis for comparing results among laboratories 

 or among samples obtained from different geographic areas. Early in 1968 

 EPA prepared a tentative procedure for a proposed standardized algal growth 

 test. It was intended to (1) identify and determine the availability of 

 algal growth-limiting nutrients; (2) quantify biological response to 

 changes in concentrations of algal growth-limiting nutrients; and (3) deve- 

 lop a rational framework for application of assay results to practical 

 problems . 



Early in the developmental effort it became apparent that emphasis 

 should be placed on a static bottle-type test. In August 1971 the "Algal 

 Assay Procedure: Bottle Test (AAP)" (National Eutrophication Research Pro- 

 gram, 1971) was published after interlaboratory precision tests at eight 

 laboratories showed excellent agreement in the data. It was then concluded 

 that the bottle test had undergone sufficient evaluation and refinement to 

 be considered reliable. It has been applied to numerous situations to 

 assist in solving and understanding eutrophication problems. The assay pro- 

 cedure is included in the Nth edition of "Standard Methods for the Examina- 

 tion of Water and Wastewater" by the American Public Health Association, et. 

 al. 



Eutrophication Control 



Since the early use of copper sulfate to control algae (Moore and 

 Kellerman, 1904), an array of ecologically based procedures has evolved. 

 What are today's options for controlling eutrophication? How can lakes be 

 protected from further degradation and, equally important, how can 

 eutrophic lakes be restored? Without question, the most promising preven- 

 tive and restorative measure is to curb nutrient supply. This objective 

 can be approached in several ways. 



Nutrient Diversion-- 



A commonly used method to reduce nutrient input is to divert point- 

 source nutrient-rich wastewater around or away from the receiving body of 

 water. The early programs at Madison, Wisconsin, and Seattle, Washington, 

 are well known. The same approach has been used more recently at Lake 

 Sammamish, Washington, and Twin Lakes, Ohio. Although these lakes have im- 

 proved, they have not responded to the same degree as Lake Washington. 



As an alternative to diverting wastewater the effluents can be sprayed 

 on the land and still protect the lake. This approach required much more 

 land area than conventional treatment facilities; hence, when land is 

 costly or not available, it may not be a viable remedy. Land requirement 

 is about 1 ha per 300-400 population served. The process requires very 

 little construction facilities, has a low energy requirement for operation, 

 and can be easily automated for unattended operation at small facilities. 

 Success is also very dependent on climatic factors, and year-round use will 

 obviously be impractical in regions with severe winters. 



The State of Michigan has completed a program of soils testing for phos- 

 phate absorption capacity, and New York State has undertaken such a program. 



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