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4.3 Water Consumption 127
Table 4.4 Common Population Densities

Persons per Acre
1. Residential areas
(a) Single-family dwellings, large lots 5–15
(b) Single-family dwellings, small lots 15–35
(c) Multiple-family dwellings, small lots 35–100
(d) Apartment or tenement houses 100–1,000 or more
2. Mercantile and commercial areas 15–30
3. Industrial areas 5–15
4. Total, exclusive of parks, playgrounds, and cemeteries 10–50
2
2
Conversion factors: 1 acre 0.4046 ha 4,047 m 0.004047 km ; 1 person>acre 2.4716 persons/ha.
typical blocks. Helpful, in this connection, are census tract data; land-office, property, zoning,
fire insurance, and aerial maps; and other information collected by planning agencies.

4.3 WATER CONSUMPTION
Although the draft of water from distribution systems is commonly referred to as water
consumption, little of it is, strictly speaking, consumed; most of it is discharged as spent
or wastewater. Use of water is a more exact term. True consumptive use refers to the vol-
ume of water evaporated or transpired in the course of use—principally in sprinkling
lawns and gardens, in raising and condensing steam, and in bottling, canning, and other
industrial operations.
Service pipes introduce water into dwellings, mercantile and commercial properties,
industrial complexes, and public buildings. The water delivered is classified accordingly.
Table 4.5 shows approximate per capita daily uses in the United States. Wide variations in
these figures must be expected because of differences in:
1. Climate
2. Standards of living
3. Type of residences
4. Extent of sewerage
5. Type of mercantile, commercial, and industrial activity
6. Water pricing
7. Use of private supplies

Table 4.5 Water Consumption

Quantity, gpcd
Class of Consumption Normal Range Average
Domestic or residential 20–90 55
Commercial 10–130 20
Industrial 22–80 50
Public 5–20 10
Water unaccounted for 5–30 15
Total 60–350 150
Conversion factor: 1 gpcd 3.785 Lpcd.