126 CHEESE MaxkING. 
246. Septic Tank. 
Much difficulty has been experienced in getting rid of the 
sewage around cheese and butter factories. The blind well has 
been a source of contamination of the water supply, and pollu- 
tion of streams has been the occasion for law suits and neigh- 
borhood quarrels. 
The septic tank offers a simple, cheap and efficient means of 
sewage disposal. It has been presented in a number of dairy 
papers. (See Fig. 60.) 
It is two feet deep and above ground, though it may be 
covered with earth. The factory must therefore be built high 
enough to empty the drains into the top of the tank. The sys- 
tem of tiles into which the tank empties should not be over one 
foot below the surface and should be perfectly level. 
247. Sewer Trap. 
At the mouth.of the factory drain there should be a sewer 
trap, which is simply an ® shaped pipe, in which water con- 
stantly stands and keeps gas from coming up from the septic 
tank. 
248. Whey Tank, How Built. 
The whey tank should be lined with galvanized iron, and 
be placed high enough for a wagon to drive under, and draw 
off the whey by simply opening a valve. The ground ought 
to be paved in such a way that the drip will run off into the 
sewer. A skim-milk weigher will facilitate an equal division 
of the whey. 
249. Elevating Whey. 
To get the whey from the vat into the whey tank, it can 
be drawn into a box or barrel, and from there forced by a 
steam jet into the whey tank. The whey should be scalded to 
keep it sweet, and after the patrons are gone every morning, 
the tank should be scrubbed out and steam turned into it to 
scald it. There should be a platform around the tank and steps 
leading up, so that a person can get into it easily. 
250. Sink, How Made. 
Another necessary thing, which is seldom found in a fac- 
tory is a good sink. It should be iron or galvanized-iron lined, 
