A privy when safely located and properly built and maintained is
satisfactory for its purpose on the farm. Privies should be built 50
to 150 feet from the farmhouse, preferably on the opposite side of the
house from prevailing winds, and at least 50 feet from the well. A site
downhill from the well is generally safest. In some cases, however,
the ground water may flow in a direction opposite to the slope of the
surface, in which case the privy should be built on the other side of
the well. Direction of flow may sometimes be learned from soil surveys,
well-driller's data, or other similar sources. A distance of at least 6
feet from fences or other buildings allows for proper mounding of the
privy and keeps it away from roof drainage from adjacent buildings.
Good, tight construction with screened ventilators keeps insects and
birds from entering, prevents rapid deterioration of the building, and
provides greater comfort for the user.
Certain features, while not essential to sanitation and satisfactory
service, add to personal convenience. A paved walkway, well protected
from cold winds and rain, is desirable. A neat, whitewashed lattice, as
shown in figure 13, an arbor covered with vines, or a hedge screen adds
to privacy.
The earth-pit privy is the simplest to build and the one most widely
used. It is not generally recommended in localities where underground
rock has crevices.
For a sanitary type of privy with reinforced concrete[9] floor, riser,
and supporting sills see figure 14. Because privy units are commonly
used as urinals, the use of impervious materials for risers and
floors facilitates cleanliness. In the colder climates, wood treated
with a preservative is durable and reduces the problem of moisture
condensation. Therefore, wood could be used if approved by the State
department of health.
[9] For information on making concrete see Farmers' Bulletin 1772, Use
of Concrete on the Farm.
When it is considered impracticable to build the slab and riser
of concrete, these parts may be of wood, as shown in figure 16.
The building itself may be as shown in either illustration. A wood
structure is easy to move to a new location.
A pit with a minimum capacity of 50 cubic feet[10] will usually serve
five people over a period of 5 to 10 years. The privy should be moved
when the pit is filled to within 18 or 20 inches of the top and a
strong disinfectant spread in the old pit before covering it with earth.
[10] Recommended by the Committee on Promotion of Rural Sanitation,
Public Health Engineering Section of the American Public Health
Association, 1932.
[Illustration: Figure 14.--Sanitary type of privy. Detailed plans and
a bill of materials for this design can be had from the United States
Public Health Service, Washington 25, D. C.]
It is important to have the earth-pit privy more than 50 feet from the
well even where the water table is not near the surface. The ground
water should flow from the well toward the privy, and it is important
that this direction of flow be determined in advance.
Wood is most commonly employed for the main part of the building. The
ground outside should be sloped as shown, to shed water away from the
building, and the roof should extend beyond the walls to shed water
away from the pit.