WSP07478

• File Number: 8272.600.60
• Description: Colorado River Basin Salinity Control Program - Basin Member State Info - Utah
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 3/1/1982
• Title: Salt Uptake in Natural Channels Traversing Mancos Shales in the Price River Basin - Utah
• Water Supply Pro - Doc Type: Report/Study

45 days between samples left in the same
solution the entire time and samples rinsed,
dried, and placed in a second batch of
l'\:) distilled water were significant. Data from
OTable D.l after 37 days (12/7/76) and Table
...;ID.2 after 48 days (12/20/76) as shown in
-.JTable 4.5 were used. The shorter period was
used for the first block of data because the
accumulated conductivity had stabilized at an
apparent saturation level by this time. For
the second block of data, the conductivities
accumulated before and after rinsing and
drying were assumed additive.

The test was first made with a two-way
analysis of variance (Neter and Wasserman
1974) with the results in Table 4.6. For the
two F-tests, the null hypotheses were defined
as 1) the four shale sources do not have the
same dissolution rates and 2) the leaching in
one batch of water does not have the same
dissolution rate as rinsing, drying, and
placing in a second batch of water. The
results show significant differences among

Table 4,5. Effect of rinsing and drying on
accumulated conductivity.

45-Day Cumulative Conductivities
(~mhos/cm @ 250C)
Shale Source Site*
1 2 3 4

Samples kept in
same solution
(37-day)

1.387
1. 594
1. 545

0.873
1. 070
1. 033

0.540 1. 048
0.497 1.081
0.497 1.060
0.829 1. 713
0.868 1.311
0.808 1. 560

~

2.284
2.269
2.297

1. 394
1. 548
1. 516

Samples rinsed I
dried and placed
in fresh distilled
water on seventh
day (48-day)

I

Shale
1.
2.
3,
4.

Source Sites:
Experimental Channel
Coal Creek Above Spring
Coal Creek Lower Site
Coal Creek Middle Site

,

Table 4.6. Analysis of variance for signifi-
cance of the effect of rinsing
and drying.

Degrees
of
Freedom

F

Level of
Significance

Source of Sum of
Variation Squares

Mean
Squared

the shales and, given that difference,
significant differences between treatments.
The data were also examined by a model
presented by Hicks (1973) that adds a third
test, one for an interactive effect between
source and treatment. The interactive effect
was also found to be significant. These
results are generally the same as those
previously found by Burges (1974).

The suggested physical explanation
is that rinsing and drying disrupts an
inhibiting physical or chemical boundary
layer and thereby increases subsequent
mineral dissolution. One could reasonably
expect the same effect in nature as shales
are dried and exposed to solar radiation
between runoff events.

The next test was to determine whether
the difference in total accumulated salt
dissolution continued to be significant
through a second cycle. The data in Table
4.7 show 'total dissolution during the
85-day leaching period. The two-way analysis
of variance produced the results in Table
4.8. Again, the statistical test shows

Table 4,7,

Total accumulated conductivity
including additional treatment.

85-day Cumulative Conductivities
(~mhos/cm @ 250C)
Shale Source Site*
1 2 3 4

Rinsed samples 1. 936 1. 218 0.812 1. 544
2.142 1. 407 0,759 1.614
2.091 1. 356 0.747 1. 552
Rinsed and dried 3.009 2.009 1.115 2.214
samples 2.907 2.253 1.158 1.851
3,037 2.151 1. 070 2.198

1.
2.
3.
4,

Experimental Channel
Coal Creek Above Spring
Coal Creek Lower Site
Coal Creek Middle Site

Table 4.8. Analysis of variance for signifi-
cance of the effect of additional
rinsing and drying.

Source of Sum of
Variation Squares

Degrees M
of ean
Freedom Squared

F

Level of
Significance

Shale Shale
Source 4.48495 3 1. 495 18.457 95 percent Source 7.501 3 2.5 15.030 95 pe reen t
Treatment 1. 58209 1 1. 582 19.531 95 percent Trea tmen t 2.531 1 2.531 15.216 95 percent
Error 0.34396 3 0.081 Error 0.499 3 0.166
Total 6.37 7 Total 10.531 7
Null Hypothesis H : "1 "2 "3 J.14; Null Hypothesis Ho: "1 "2 "3 \l4;
0
'1 '2 '1 '2

35