WSP06476

• File Number: 8271.300
• Description: Colorado River Basin Salinity Control Program - General Information and Publications-Reports
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 6/1/1978
• Title: Salinity Management Options for the Colorado River -- Part 1 of 2 -- Title Page - Page 168
• Water Supply Pro - Doc Type: Report/Study

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Table 21. RegreB~ eBtf.'m4teBftw length of average
li!etf.'me and saUnit'll.

Water Heaters:

In L'5.43771.0.42435nn TDS).0.993220n#PERS/UN1T)
(4.967)a.b (3.9.25)b

+ 0.36828 (DUMMY)
(2.406)b

F . 13.34b

R' . 0.60

Galvanized Wastewater Pipes:

In L' 7.42425.0.79571 On TDS)+1.05941 (DUMMY)
(4.227)b (3.248)b

F . 1l.23b

R' . 0.51

Galvanized Water Pipes:

L' 16.56015 .0.00666 (TDS). 3..78336 (DUMMY)
(1.584) (1.883)

F . 3.94c
R'" 0.23

Brass Faucets:

In L' 6.35863.0.69277 On TDS) + 1.28617 (DUMMY)
(1.351) (1.420)

F = 1.4

R' = 0.15

Dishwashers:

In L = 4.05324.0.34538 On TDS) + 0.42955 (DUMMY)
(3.175)b (1.870)

F = 5.18c

R' = 0.30

Washers:

L = 9.62161 .0.00360 (TDS) + 1.45762 (DUMMY)
(1.933) (1.305)

F = 2.07

R' =0.15

Garbage Disposals:

In L" 2.82352.0.13076 (In TDS) + 0.03794 (In DUMMY)
(1.013) (0.145)

F = 0.55
R' = 0.05

aThe values in parentheses arc T -Statistics.

bDenotes statistically different from zero at the 99%
level of a 1-tailed'test.

cOenotes statistically different from zero at the 95%
level of a l.tailed test.

With the completion of the Central Arizona
Project in the mid.1980s municipal water from the
Colorado River will be delivered to Phoenix, Tucson,
and the respective surrounding areas. Since both
locations will potentially be affected by the salinity
content of Colorado River water, it is important to
assess the magnitude of economic Impacts reasonably

expected under present and future conditions. ''I'he
salinity content of municipal water currently used in
the Phoenix area was estimated to average 785 mg/l
while Tucson's average was much lower at 550 mg/l.
Results from the Si'4SA of Las Vegas indicated that
varying water qualities exist for different locations.
For example, Las Vegas (including North Las Vegas)
was estimated to average 450 mg/l while Boulder City
and Henderson had poorer quality water at about 680
mg/1.

Table 22 containB the number of responses
tabulated from plumbers and appliance dealers in each
of the five locations. In order to improve the statistical
analysis, two groups were formed. One group
consisted of the SMSA of Phoenix and the locations of
Boulder City and Henderson. The water quality of
these locations is approximately in the same range;
therefore, in order to increase the usefulness of the
small number of observations In Boulder City and
Henderson, these three locations were combined to
form one group with estimated average water quality
of 735 mg/1.

The second group was composed of Tucson and
the remainder of the Las Vegas SMSA. These areas
average between 450.550 mg/l and have approxi-
mately an equal number of observations. An average
water quality of 500 mg/I was assumed to be
representative of this group.

Table 22. Tabulated responses.

Phoenix
Tucson
Las Vegas
Boulder City
Henderson
Total Responses Obtained

Plum bing

126
38
30
6
3
173

Appliances

21
31
21
4
4
60

Statistical SlgaIfI.....e

A test was used to determine statistical
significance of mean lifetimes between the two
groups. Table 23 lists each of the household items
surveyed and the resulting mean lifetimes. Statistical
significance was found to exist between the two
gr-oups for galvanized water pipes, water heaters,
toilet flushing mechanisms, dishwashers, and garbage
disposals. No significant differences were found for
galvanized wastewater pipes, brass faucets, clothes
washers, and evaporative coolers. In the cases where
a significant difference exists, mean lifetimes of items
at the lower salinity level are longer which support the
hypothesis that poorer quality water reduces the
economic usefulness of certain items.

Economic Damage Computations

Estimation of monetary losses (additional costs)
for a typical household was derived by calculating the

22