Number of Analysis.

MISCELLANEOUS ANALYSES-Expressed in Parts per 100,000-CONCLUDED.

Origin of Sample.

45

NOTES ON SOME OF THE SAMPLES OF WATER

EXAMINED IN THE LABORATORY.

No. 293. This sample was taken from a well around which various sources of pollution were grouped too near-the sink drain was at a distance of sixty feet, the privy thirty-five feet, and the stable, barn-yard and pig-pen from twenty-five to thirty feet. The analysis gives evidence of pollution with organic matter.

Nos. 294 and 315. Grass Brook, Fort Fairfield. The analyses were made to determine the suitability of the water as a village supply. Both analyses show that the water is organically very pure. The brook arises from springs. The degree of hardness of the water is much below that which is obtained from wells in all that region.

No. 295. This sample was taken from the Aroostook river about midway between the two shores at Fort Fairfield for the purpose of comparing the results of its examination with that of No. 294.

No. 297. From the report to the sender: "You will notice that the total solids is very low in quantity, that it is a very soft water, and that the indications of organic matter as represented by the amount of chlorine, and free and organic ammonia are very slight indeed. It is apparently a very good spring water for drinking purposes."

No. 298. Silver lake, Dexter. The following report was made: "I enclose the results of the analysis of the sample of water from Silver lake. In these results there is nothing which would justify me in pronouncing the water unsuitable for the purposes of a public water supply. There is, however, rather a larger quantity of free ammonia and also of organic ammonia than is found in the best of lake waters in the State. The average free ammonia in twenty-nine analyses of public water supplies, taken from lakes and ponds in this State, is only .001, and the average free ammonia in the supplies taken from rivers is only slightly greater. The organic ammonia in the lake supplies is .010. I should like further information in regard to your method of taking the sample,-that is, the distance from the shore, etc. What is the nature of the growth around the lake?"

Nos. 299 and 391. These two samples were taken from a deep well drilled through ledge and the results are not so favorable as

would generally be expected, but are quite like what we have somewhat frequently found in deep wells drilled through rock. Pending further examinations of samples from this well, a positive opinion was not given as to the quality of the water. It will be noticed that the results obtained from the two samples are quite different, and the difference may have been due in part to the fact that the bottle in which No. 299 came was not free from suspicion. We may add that sources of pollution were within fifty feet of the well,— · the privy, stable, barn-yard, and pig-pen.

No. 300. From a well situated fifty feet from sink drain and privy. There was a suspicion that the bottle in which the sample was sent had not been made chemically clean. Another sample received later in the season in a bottle sent from this office yielded different results, as will be seen in the tabulation. (See No. 384.) No. 301. A spring water of good quality for drinking purposes. No. 302. A well situated in gravelly soil, about thirty feet from a privy and forty feet from a barn-yard. The chemical results make it apparent that the organic matter is quite thoroughly oxidized in passing through the soil, but the chlorine and nitrate results show that the water is to be regarded with suspicion, notwithstanding the small amount of organic matter present.

Nos. 303 and 304. "I enclose the results of the analyses of the last two samples of water which you sent, Nos. 303 and 304, and also a blank showing the results of the examination of No. 217 which you sent last fall, report of which has already been made. As I telegraphed to you, the differences which are found in the character of the water by means of the chemical processes are so small, that the chemical examinations will not help you much in making a decision as to which source would furnish the more suitable supply. It is never well to base a decision upon a single chemical analysis, for the reason that the character of certain sources of supply varies very much at different times, but, as far as can be judged from the examinations which I have made, any of the three sources of which you have submitted samples to me would furnish a good water, judging, of course, from the chemical point of view alone. You should make a careful examination of all the surroundings of the proposed sources of supply and take into account all present and prospective possibilities of pollution and choose accordingly. It is noteworthy that all of the samples are very soft waters, especially the sample which you sent last fall, and No. 304, or the