832 



PARKS 



Water Trough should 

 not discharge across 

 trapdoor. 



Put i extra rod in concrete 

 along each edge <f manhole. 



Raise concrete 1" around 

 d pump 



Chlorination of water. Chlorine is a gas at ordinary temperature and 

 atmospheric pressure. Chlorine will combine with the organic matter in 

 the water and as germs are organic in nature they are also attacked and 

 killed. In the purification of water chlorine is used either in the pure form 

 (known as liquid chlorine) or as calcium hypochlorite (chlorinated lime, 

 bleaching powder, bleach and chloride of lime). 



In the application of chlorine or calcium hypochlorite to the water 



the amount to be added is cal- 

 culated as so many parts of free 

 chlorine to one million parts of 

 water. Eight and one-third 

 pounds of liquid chlorine when 

 added to one million gallons of 

 water will give one part chlorine 

 to one million parts of water. 

 Calcium hypochlorite normally 

 contains approximately thirty- 

 three and one-third per cent of 

 free chlorine, and twenty-five 

 pounds of this compound in one 

 million gallons, or four-tenths of 

 an ounce in one thousand gal- 

 lons of water, will give one part 

 of free chlorine per million parts 

 of water. These figures consti- 

 tute the basis for computing the 

 amount of chlorine or calcium 

 hypochlorite to be added to the 



SECTION 



PLATE No. 308. INCLOSED SPRING WITH CONCRETE 



PLATFORM AND TRENCH TO PREVENT SURFACE 



WATER FROM ENTERING THE SPRING 



(Pennsylvania State Department of Health.) 



water supply. 



Wherever possible, all water 

 to be used in parks and recrea- 

 tion areas that comes from a 

 source other than a community water system should be purified before 

 being delivered to the user. In the case of picnic parties, small camps, 

 hiking parties, where the supply of water to be used comes from streams, 

 lakes, springs or wells of unknown purity, the drinking water can be 

 chlorinated either by the individual hiker, picnicker or camper or by the 

 leader of any group or by the person in charge of the park or forest 



area. 



One of the safest and most practical means of chlorinating water for 

 small groups is through the use of the so-called Lyster Bag method. The 



