METHODS FOR PREVENTING BAD EFFECTS Dl^E TO ALOiE. 18 



Pexxsylvasia — Continued. 



The growth affected the taste of the water nn lioiHu};, Imt was not rejrarded as 

 danirerous to liealtli. 



A very lishy taste and smell. 1 have heen unal)le to locate, l»nt had an idea it 

 came from vejjetation. 



The water (hiring the autumn in so foul in ta.ste and odr)r that it was necessary 

 to slnit off the supjdy. The odor is similar to that of decayed fisii. 



The first season of usin*^ reservoir the water hecame so tishy that it was almost 

 unfit for use. Since that, owing to our care of reservoir, we have had no trouble 

 whatever. 

 Tk.vas: 



.\t this time of the year al<,M' are fierce; sonu' days we an' on titp and some 

 <lays the alf^a- are on top. Costs us an average of $25 a month for cleaning out 

 alga" from two reservoirs. 

 Wisconsin: 



Universal complaint, causid liy the odor and taste due to algfc. 



METHODS IN USE FOR PREVENTING BAD EFFECTS DUE TO ALG^. 



Ju order to prevent the odors and tastes above described, engineers 

 and those in eharo-e of water sujiplies have tried \arious remedies, 

 none of which lias l)een perfectly satisfactory. Since few of the 

 aloiv can deveh)p withont simlioht. the most fre(]uent reconnnenda- 

 tion has been to cover th(> reservoir, and this method has proved suc- 

 cessfnl in a few instances. However, the expense involved is so great 

 as to make the remed}' ])r()iiil)itive in most cases, and other methods 

 have had to be resorted to. One precaution which is now almost iini- 

 versalh' recommended as a means of preventing the growth of algje is 

 to remove all the organic matter possible from the reservoir and to keep 

 the source of supply as free as can be from dead and decaying animal 

 and vegetable matter. In one notable instance millions of dollars 

 have been spent in the removal of earth and the substitution of gravel 

 at the bottom of an immense new reservoir. It remains to be seen, 

 however, whether this Avill be sufficient to insure permanent freedom 

 from these troublesome plants. It is certain that attempts of this 

 kind will delay the appearance of alga? in quantity, and, wherever it 

 is possible to do so, every efi'ort should be made not onh' to clea^i up 

 the reservoir at the time of its construction, but to keep it as free as 

 possible from organic matter after it is filled. In addition to cleanli- 

 ness a direct pumping sj'stem with duplicate, in case of breakdown or 

 repairs, has often been recommended for use with ground water, 

 which usually produces a more luxuriant growth of algfe and similar 

 organisms than surface water. Where it has been necessaiy to store 

 such water, it has been advisa])le to limit the capacity of the reservoir, 

 and frequenth' this storage is only intended to be used in case of fire. 

 Even so, the cleansing of the reservoir and the frequent flushing of 

 the water mains has been considered necessaty. In storing surface 

 water subdividing the reservoir is occasionally resorted to, and means 



