Theodore Clifford Phillips

“ Intermittent downward filtration may be used where there is a considerable area of sandy soil, and also where a high degree of purification is necessary.
Chemical precipitation does not require a large area for its operation and used alone does not give a high degree of purification. Where land and material for beds is expensive, and partial purification is sufficient, this system may be used.
The septic tank requires a small area. The odors are not offensive and cannot be noticed 100 feet away. The effluent may be discharged into small streams and soon loses its identity. ”

“ The darkened ill ventilated and modestly heated conditions in the tank are all conducive to the propagation of a micro-organism known as bacteria. The activity of these organisms causes a chemical decomposition of the organic matter in the sewage a part passing off as gas and a 25part passing off in the effluent as inorganic matter, while another portion is deposited in the bottom of the tank as sludge. ”

“ To obtain the highest efficiency the sewage must be applied intermittently and there must be a large percentage of voids in the sand.
Experiments made on especially prepared beds at Lawrence, Mass. show that by treating 85000 gallons per acre per day, 94 percent of the organic matter and 98 percent of the bacteria are removed, and by treating 60,000 gallons per acre per day, 97 to 99 percent of the organic matter may be removed. The above data shows that 100,000 may be successfully treated with a five foot bed of sand. ”

“ A septic tank for treating 1,000,000 gallons of sewage per day will cost less than $10,000 and the cost of maintenance will be about $1.00 per 461,000,000 gallons treated.
Conclusion In selecting a method of sewage disposal, the conditions, surroundings, and requirements of the city should be carefully studied and analyzed, and judgment and discretion must be used. A matter of so much importance to the community should be placed in the hands of men qualified to make a proper solution of the problem. ”

“ Soc. Vol. 7 No. 7 shows the volume of sewage per acre per day (yearly average) to vary from 2155 to 29450 gallons, and the average depth per annum varies from 2.4 to 32.8 feet.
The nineteenth annual report of 9the Massachusetts State Board of Health 1888 states that on an ordinary farm in Massachusetts 2500 gallons per acre per day are as much as could be applied to any valuable grass crop. This would require such a large area for large cities that irrigation could not be depended upon for preventing the pollution of streams. ”

“ It is evident from the above report that the irrigation system can be used to advantage only where large tracts of low land can be obtained at a low cost, and where help and plenty of cheap labor can be obtained.
10 Intermittent Downward Filtration Filtration means the concentration of sewage on an area of especially chosen porous ground, or on an especially prepared bed as small as will absorb and purify it. The intermittency of application is a necessary requirement even in suitably constituted soils wherever complete success is arrived at. ”

“ The reduction of organic matter in solution is considerable, averaging 17 percent.
This sludge at the bottom is a black muddy looking silt-like deposit containing about 60 percent of water and 5 percent of organic matter. Its value as a fertilizer is small.
27Although the amount of sludge is relatively small the accumulation requires removal occasionally, three or four times a year.
It is estimated that for every 1,000,000 gallons sewage there is about 3 cubic feet of dry matter. By chemical precipitation this would amount to from 20 to 25 cubic feet per 1,000,000 gallons. ”

“ It is conceded now by the highest authorities on this subject that the tank should have a capacity equal to from one fourth to one half of the average daily flow.
Concerning the conditions for which the various processes are applicable, it may be said that the dilution process is used when advantage may be taken of natural resources. This method can be utilized by most cities situated along rivers or streams large enough to sufficiently dilute 42and carry away the sewage, and fulfill sanitary requirements. ”

“ The sewage enters near the bottom of the tanks. The sludge settles to the bottom and the effluent rises to the top, where it is carried away to three of the filter beds. These three beds are in continuous use. A fourth bed is out of use while it is washed and allowed to rest for one day.
The total area of the beds is 5550 square feet. The flow through the beds is about 8,000,000 gallons per acre per day. ”

“ The total cost of the disposal plant was $20755.00. The cost of operation and maintenance for the years 1897 and 1898 was $1290.00 and $1567.43 respectively. The average amount of lime used during this time was 95000 pounds yearly.
Two men perform all the labor necessary for the operation of the plant.
From the chemical analyses given in the Engineering Record Jan. 13, 1900 of the sewage and effluent, averages representing five months show the efficiency in albuminoid ammonia to be 40 percent and oxygen required 30 percent. ”

“ The average quantity of sewage pumped to the farms and distributed amounts to from 6,000,000 to 7,000,000 gallons per acre per year, or in other words each acre serves for 750 people. The area farmed is divided into small beds about 150 by 200 feet separated from each other by slight embankments and ditches for distributing the sewage over the surface. ”

“ The first has a cubic capacity of 93 percent of the total daily flow, while the second has a capacity of 7.5 percent of the daily flow.
When the capacity of the tank is as small as at Champaign the bacteria do not have time to act upon the sewage as they would if the flow was not so rapid. ”

“ It was designed for 98000 gallons capacity. The sewage is allowed to remain in the tank nearly 24 hours. The tank is used in conjunction with five beds in which further purification is used. The beds are filled with coke breeze and one is always resting for a week at a time. The tank is made nearly air tight by an arched roof and any gasses collecting may be burned at a vent. ”

“ The material was shipped a distance of 90 miles and resembles ordinary ballast used for rail roads. The largest pieces were thrown along the sluice way to prevent excessive washing. The finest of the sand 15was of a size which would be considered too fine for good mortar sand. ”