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The Evolution of the Conservation Movement, 1850-1920
Conservation by sanitation; disposal of waste (including a laboratory guide for sanitary engineers) by Ellen H. RichardsStandards
Nichols, "Water Supply," 1883: " ... there will always be difficulty in deciding how near to any limit a suspicious water may come and still be used with a reasonable degree of safety. To condemn water without sufficient cause is of course undesirable,
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as the procuring a different supply may involve considerable expense.1
[Note 1: 1 The Massachusetts State Board of Health has followed this rule in spite of all pressure.]
"Moreover it cannot be insisted on too strongly that different classes of water cannot be judged by the same standard, and the results of the analysis of waters belonging to different classes ought not to be put in the same table or otherwise arranged so as to invite comparison (the waters of the same geological horizon and area may be compared).
"To fix, however, a definite standard which will apply to all waters and by which any one can judge of a given water from the numerical results of analysis is impracticable. Every doubtful water must be considered by itself with all the light that can be brought to bear on it."
"Dr. Drown reporting to Massachusetts Board of Health (1890) says: 'To determine whether or not a water has been polluted by sewage, a chemical analysis is sometimes insufficient, sometimes it is superfluous. It does not need a chemical examination to decide whether a stream has been polluted by sewage when one can see the sewage flowing into it.' And, again: 'Standards are relics of days in which the harmfulness of water was supposed to be the direct result of the injurious action of specific substances found in it. The theory of to-day is that it is (in the large majority of cases) to the present of micro-organisms in water that its harmful influence is due, and that the results of chemical analysis have their highest value in the light that they throw on the quality of the water from the standpoint of bacterial contamination.' 'An opinion regarding the wholesomeness of a water must be based on all the information obtainable about it, such as location, environment, and source of the water, and the character and population of the drainage area.'"
Mason, "Water Supply,"1896: "The term 'standard' is doubtless a poor selection. A hard and fast standard is simply an impossibility. Results which would be considered satisfactory
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for one locality might be entirely inadmissible in another, Local standards are the proper ones by which to be guided, and it is to be regretted that local 'normals' are not more frequently found on record.
"Mr. Reuben Haines recommended the following figures representing the averages of thirty-four different determinations of uncontaminated waters as standards for pure waters in the neighborhood of Philadelphia.
J. C. Thresh, "The Examination of Waters and Water Supplies," 1904.: "At the beginning of this discussion we have spoken of the doubtful value of standards of purity of water based on the amount of the nitrogen compounds which it contains. In the case of ground waters there is an ideal standard of purity which is at the same time not an impossible one namely, complete freedom from unoxidized or partly oxidized compounds of nitrogen. We do not know, as has been already explained, that a water which reaches this standard is safe if at the same time it contains much nitrogen completely oxidized, but we do know that as we depart from this standard we enter the region of known danger. It has been a very general custom hitherto to set limits for each of the substances beyond which the water should be regarded as polluted or as unfit for drinking.
"The application of these standards of purity made the interpretation of analyses a very simple matter but of very doubtful value.
"Before proceeding to discuss the results obtainable by the various methods of analysis, let me once more emphasize the importance of the inspection of the source of supply, both in detecting possible sources of pollution and in enabling correct inferences to be drawn from the results of the chemical, bacteriological,
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and microscopical examinations. This is now being recognized by sanitarians generally. In fact, Gruber, of Vienna, lays so great stress upon an examination of the source, as to assert that in ordinary cases even a bacteriological examination of the water can be dispensed with, and Flugge considers that an inspection carried out with the unaided senses, is the most desirable method, and seldom needs to be supplemented by chemical, bacteriological, or microscopical investigations.
"In America, considerable stress is laid upon the systematic examination of surface waters by biological methods, the number and genera (or sometimes species) of the organisms found being recorded. In this country little study has been made of the low forms of life (save the bacteria) which occur in water although more reliable information as to the character of a water can be obtained sometimes by this method than by any other.
"I am convinced that standards cannot be adopted for any waters, but there is very little doubt that a water which gives no indications of the presence of the B. coli communis in 10 cc., of Streptococci in 50 cc.(?), and of the spores of B. enteritidis sporogenes in 500 cc., is at the time of examination so free from sewage pollution that it may be certified as safe for all domestic purposes, providing its source is satisfactory.
"This standard is attained by waters from all properly protected springs and from properly constructed deep wells. Upland and moorland surface waters, collected in reservoirs, I have regarded as satisfactory if they afforded no evidence of the presence of the Bacillus coli communis in a few cubic centimeters, and especially if the B. enteritidis sporogenes could not be detected in 250 cc.
"... As the detection of sewage or manurial contamination by bacteriological methods must depend upon the discovery of the bacteria characteristic of excremental matter, a very important point remains for discussion, viz., the amount of water which should be used for the examination. Chemical analysis cannot be depended upon to detect pollution with 1 per cent of
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sewage, or with 1 per cent of most sewage effluents, which sewage effluents might practically contain all the organisms of the original sewage. Bacterioscopic analysis may be depended upon to detect a much smaller quantity of polluting matter. Unfortunately the number of the selected organisms found in sewage varies enormously, and the proportion of each to the others varies in every sample. In relative abundance they occur in the following order: Bacillus coli communis, streptococci and spores of the Bacillus enteritidis sporogenes of Klein. Houston and Klein find the variations are within the following limits:
"Assuming that efforts are limited to the detection of pollution corresponding to one-millionth part of sewage containing the minimum number of these organisms, it is obvious that 10 cc. of the water would be required to give indication of the presence of the bacillus coli, 1000 cc., or one liter, to afford evidence of streptococci, and ten liters for the detection of the spores of the B. enteritidis sporogenes. ...
"On the other hand, assuming the polluting matter to contain the maximum number of the above organisms, one to two cubic centimeters would suffice for the detection of the B. coli communis, 100 cc. for streptococci, and 500 cc. for the spores of the B. enteritidis sporogenes.
"Prof. Sheridan Delepine, 1904, lays considerable stress on the importance of bacteriological examinations. As there is no general standard of purity he selects feeders which are uncontaminated, examines the water bacteriologically, and takes the results as a 'natural standard.'
"'To find such feeders,' he says, 'the bacteriologist of course inspects the gathering ground himself, and after noting the configuration and nature of the ground, the course of the feeder, its relation to the slope which it drains, the absence or presence
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of cultivation areas, of paths, of houses, the possibilities of human traffic, the presence of cattle or sheep, he can then determine whether the feeder inspected is likely to be contaminated or not. ... It is necessarily free from any bacteria associated with decomposing organic matter, human or animal diseases (provided no carcass of a dead animal is found in its neighborhood). Such as water should be good, provided no abnormal chemical constituents are present. Even under these conditions water is liable to variations, according to the state of the weather.'"
Turneaure and Russell "Public Water Supplies" (1908, p. 126): "Desirable as it would be to have definite standards of water analysis that would apply to all waters, such are nevertheless impossible. The changing conditions under which various potable supplies occur make it altogether out of the question to have a standard that would be of general application."
In accordance with the tendency of each State to deal with its water problems through some Commission or Board, legal standards are being set up by which the authorities in each State may govern themselves in dealing with questions of prohibition of pollution or in compulsory measures of prohibition. The State of Pennsylvania has issued a definition of wholesome water (above, p. 57).
The State Board of Health of Illinois1 which covers an enormous area with very variable soil and water conditions, has adopted provisional standards as its guide. Other States are virtually doing the same thing for legal purposes. These provisional standards are in the right line, changeable to meet new knowledge, but finishing a basis for compulsion in carrying out State law.
[Note 1: 1 Bulletin Vol. 4, Number 5, May 1908.]
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