159 



The second plant of any size was built at the Southern Hospital near 

 Evansville. It was a chemical precipitation plant using lime or soda ash. 

 After precipitation in large concrete tanks the sludge was pumped to a 

 press; the resulting cake of organic matter was dumped into a cistern 

 made for the purpose. The cost of the plant was originally $18,000, and 

 the cost of operation about $1,200 per year. 



It was replaced in 1905 by a three-step process which included tanks, 

 stone filters and finally intermittent sand filters. 



The conditions here required a high degree of purification. The popu- 

 lation is approximately 1,000, and the cost of operation is probably less 

 than $200 per year. The cost of reconstructing the plant was $10,000. 



In 190S the city of Bloomington constructed a system of sanitary sew- 

 ers and installed a purification plant consisting of a central concrete tank 

 and two series of stone filters, the latter being sprinkling filters. 



Angola, a city of about three thousand population, is now construct- 

 ing a system of sewers and a sewage purification plant consisting of sedi- 

 mentation tanks, stone filters for the first treatment and sand filters for 

 the final. The city will build a second plant next year. The cost of the 

 two plants will be about $20,000. The cost of operation of these small 

 municipal plants will be watched with interest, as it will determine in 

 some measure the details of future designs. 



The city of Laporte, with a population of 12,000 and rapidly growing, 

 is completing plans for a system of sewers and is providing for sewage 

 purification. 



The city of Shelbyville is also constructing a system of sanitary sew- 

 ers, and the entire town looks forward to sewage purification at some time. 



There is no question but that the educational propaganda which the 

 State Board of Health has been pursuing is bearing fruit. The state in- 

 stitutions themselves are with a few exceptions well provided with a good 

 water supply and sewage purification plants where they would otherwise 

 prove a danger to neighboring communities. 



There can be no doubt but that this movement toward pure water will 

 have a measurable effect upon the morbidity and mortality of the State. 



Purdue University. 

 Lafayette, Ind. 



