The feces and urine of wannblooded animals 

 are the most significant potential sources of water- 

 borne pathogens capable of infecting man. Man 

 has contracted cholera, typhoid, leptospirosis, 

 schistosomiasis, and other diseases, witii water as 

 the vector, where the source of contamination was 

 traced to animals. Time lapse and magnitude of 

 contamination are critical factors in the degree of 

 hazard. The problem now becomes one of selecting 

 an appropriate indicator and numerical limits that 

 will indicate contamination by excreta of warm- 

 blooded animals. 



The use of total coliforms as an indicator has a 

 long history, most recently through counts on 

 membrane filters. While the total coliforms count 

 may be a satisfactory indicator in certain respects, 

 the Subcommittee believes that the variable corre- 

 lation of total coliform content with contamination 

 by excreta suggests that coliforms are not a satis- 

 factory indicator of the possible presence of patho- 

 gens in recreational waters. 



The portion of the total coliforms in water that 

 are of fecal origin may range from less than 1 per- 

 cent to more than 90 percent. At the 1 percent 

 level, a limit of 1,000/100 ml total coliforms 

 would constitute an undue limitation on availabil- 

 ity of water for contact recreation. At the 90 per- 

 cent level, a limit of 1,000/100 ml would consti- 

 tute a threat to the health of the contact recreation 

 user. Thus, total coliform criteria are not adequate 

 for determining suitability of waters for use for 

 contact recreation. 



Fecal streptococci in combination with total 

 coliforms are being used in sanitary evaluation. 

 Selection of techniques to be applied and the inter- 

 pretation of results are in a state of flux and un- 

 certainty. Problems include the vmresolved ques- 

 tion of whether or not all types of fecal strepto- 

 cocci found in warmblooded animals are revealed 

 by the tests, the fact that appreciable numbers of 

 streptococci from other sources (plants and in- 

 sects) yield positive test results, and added time 

 and manpower requirements for monitoring agen- 

 cies. Fecal streptococci should not be used as pri- 

 mary criteria, but are useful as a supplement to 

 fecal coliforms where more precise determination 

 of sources of contamination is necessary. 



It is the Subcommittee's opinion that of the 

 groups or organisms commonly employed in evalu- 

 ating sanitary conditions in surface waters, fecal 

 coliform is by far the best choice for use in criteria 

 for contact recreation. Two facts will demonstrate 

 that fecal coliforms are superior indicators of re- 

 cent contamination with feces of warmblooded 

 animals. Approximately 95 percent of the total 

 coliform organisms in the feces of both birds and 



mammals yield positive fecal coliform tests. A 

 similar portion of the total coliform organisms in 

 samples of uncontaminated soils and plant mate- 

 rials yield negative fecal coliform tests. It is im- 

 portant to note that use of fecal coliforms as an 

 indicator does not add to the complexity or ex- 

 pense of monitoring. 



There is an urgent need for research to refine 

 correlations of various indicator organisms, in- 

 cluding fecal coliforms, to water-borne disease. 

 The Subcommittee feels that the Public Health 

 Service's three epidemiological studies on bathing 

 water quality and health are the only base available 

 for setting criteria. These studies were far from 

 definitive and were conducted before the accept- 

 ance of the fecal coliform as a more realistic meas- 

 ure of a health hazard. The studies at the Great 

 Lakes (Mich.) and the Inland River (Ohio) 

 showed an epidemiologically detectable health ef- 

 fect at levels of 2,300-2,400 coliforms per 100 ml. 

 Later work on the stretch of the Ohio River where 

 the study had been done indicated that the fecal 

 coliforms represented 1 8 percent of the total coli- 

 forms. This would indicate that detectable health 

 effects may occur at a fecal coliform level of about 

 400 per 100 ml; a factor of safety would indicate 

 that the water quality should be better than that 

 which would cause a health effect. 



The Santee project correlated the prevalence of 

 virus with fecal coliform concentrations following 

 sewage treatment. Virus levels following secondary 

 treatment can be expected to be 1 PFU per milli- 

 liter with a ratio of one virus particle per 10,000 

 fecal coliforms. A bathing water with 400 fecal 

 coliforms per 100 ml could be expected to have 

 0.02 virus particles per 100 ml (one virus particle 

 per 5,000 ml.) 



On these bases, the committee recommends the 

 following. 



Recommendation: Fecal coliforms should be used as 

 the indicator organism for evaluating the microbiologi- 

 cal suitability of recreation waters. As determined by 

 multiple-tube fermentation or membrane filter pro- 

 cedures and based on a minimum of not less than five 

 samples taken over not more than a 30-day period, 

 the fecal coliform content of primary contact recreation 

 waters shall not exceed a log mean of 200/100 ml, nor 

 shall more than 10 percent of total samples during any 

 30-day period exceed 400/100 ml. 



It is the position of the Subcommittee that, if 

 neither excessive health hazards nor undue restric- 

 tion on availability of recreational waters are to 

 occur, sanitary criteria for water contact recreation 

 should reflect the foregoing recommendations. The 

 Subcommittee recognizes that localized bacterial 

 standards may be justified, if based on sufficient 

 experience, sanitary surveys, or other control and 

 monitoring systems. For greatest value, such ac- 



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