The Field Lysimeter Test Facility (FLTF) at the Hanford Site

The Field Lysimeter Test Facility (FLTF) at the Hanford Site: Installation and Initial Tests

G. W. Gee R. R. Kirkham J. 1. Downs M. D. Campbell

February 1989

Prepared for the U.S. Department of Energy under Contract DE-AC06-76RLO 1830

Pacific Northwest Laboratory Operated for the U.S. Department of Energy by Battelle Memorial Institute

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THE FIELD LYSIMETER TEST FACILITY (FLTF) AT THE HANFORD SITE: INSTALLATION AND INITIAL TESTS

G. W . Gee R. R. Kirkham J. L. Downs M. D. Campbell

February 1989

Prepared f o r t h e U.S. Department o f Energy under Cont rac t DE-AC06-76RLO 1830

P a c i f i c Northwest Laboratory Rich1 and, Washington 99352

EXECUTIVE SUMMARY

Pacific Northwest Laboratory (PNL) and Westinghouse Hanford Company

(WHC) have cooperated to develop the Hanford Site Protective Barrier Develop- ment Program. The objectives of this program are to test barrier design concepts and to demonstrate a barrier design that meets established perform-

ance criteria for use in isolating wastes disposed of near-surface at the

Hanford Site. Specifically, the program is designed to assess how well the

barriers perform in control 1 ing biointrusion, water infiltration, and erosion, as well as evaluating interactions between environmental variables

and design factors of the barriers. To assess barrier performance and design with respect to infiltration control, field lysimeters and small- and large- scale field plots are planned to test the performance of specific barrier designs under actual and modified (enhanced precipitation) climatic conditions.

As part of these efforts, PNL and WHC jointly developed the plans and

built the Field Lysimeter Test Facility (FLTF). This facility is located in the 600 Area of the Hanford Site just east of the 200 West Area and adjacent to the Hanford Meteorological Station. The FLTF data will be used to assess the effectiveness of selected protective barrier configurations in con-

trolling water infiltration. The facility consists of 14 drainage lysimeters (2 m dia x 3 m deep) and four precision weighing lysimeters (1.5 m x 1.5 m x 1.7 m deep). The lysimeters are buried at grade and aligned in a parallel configuration, with nine lysimeters on each side of an underground instrument chamber. The lysimeters were fi 1 led with materials to simulate a multilayer protective barrier system. Data gathered from the FLTF will be used to compare key barrier components and to calibrate and test models for predicting long-term barrier performance.

Water infiltration tests at the FLTF are designed to test the interactions of vegetation, surface gravel, soil thickness, and precipitation changes on drainage from a multilayer soil system. The FLTF tests consist of

seven treatments: 1. ambient precipitation, vegetated soil (1.5 m deep)

2. ambient precipitation, bare soil (1.5 m deep)

3. twice average precipitation, vegetated soil (1.5 m deep)

4. twice average precipitation, bare soil (1.5 m deep)

5. ambient precipitation, surface gravel admix/vegetation (1.5 m deep)

6. ambient precipitation, vegetated soil (1.0 m deep)

7. precipitation-to-breakthrough, bare soil (1.5 m deep).

These treatments are replicated in both the drainage and weighing lysimeters.

Details of the construction, backfill, instrumentation, and initial testing

for the FLTF are provided in this document.

The experimental design of the FLTF allows drainage to be measured

directly from each of the 18 lysimeters by gravimetric weighing of the out-

flow water. Water balance components are also measured. A neutron probe is

used to measure storage changes in the top 1.5 m of each lysimeter. The

four weighing-lysimeters are used to measure both precipitation and evapo-

transpiration with a precision of + 0.02 mm water. Additional climate data

(e.g., solar radiation, air temperature, humidity, wind speed, etc.) for the

FLTF are avail able from the adjacent Hanford Meteorological Station.

In November 1987, tests were begun to measure water infiltration, evapotranspiration (ET), redistribution within the soil profile and drainage.

These water balance tests are planned to continue through 1995. Vegetation

representative of the native pl ant communi ty was seeded and transpl anted onto

10 of the 18 lysimeters. The report documents the water balance for each of

the 18 lysimeters. Surface evaporation and ET rates in irrigated and non- irrigated lysimeters were significant in the winter months. Water losses by ET during the winter and early spring were sufficiently high to maintain a

water deficiency in the surface soil, thus preventing drainage. The vegetated lysimeters exhibited more water loss for the 8-month (November 1987

through June 1988) test period than the bare surface (nonvegetated) lysim-

eters. Only the two lysimeters treated to breakthrough (D09-7 and Dll-7)

yielded drainage during the 8-month test period. The expected precision of

replicated drainage tests is f 1 L (equivalent to k0.04 cm water).

Data on the hydraulic properties of the materials used as the soil cover

in the FLTF are required as input to simulate the FLTF barrier tests using

computer modeling. These data include saturated hydraulic conductivity,

water retention characteristics, and selected physical properties, such as bulk density and particle-size analysis, which are useful in characterizing the vari abi 1 i ty of soi 1 materi a1 s. Laboratory data on the hydraul i c properties of the surface soil materials taken from the McGee Ranch and used to fill the FLTF lysimeters indicate that the soil material has a relatively uniform texture (loam to silt loam) throughout all lysimeters and that available water storage in 150 cm of soil for all the test samples exceeds 42 cm of water (or more than 2.5 times the average precipitation of 16 cm/yr). The water retention characteristics of this soil are described by analytical expressions (Van Genuchten parameters) that can be used in computer simulations of the lysimeter water balance using the UNSAT-H model. Field data are currently being obtained to evaluate moisture storage profiles and to measure saturated hydraulic conductivity by in-place testing. These data will be compared to previous laboratory tests to establish correlations (where possible) to re1 ate field-measured properties to such 1 aboratory- determined properties as part i cl e-si ze analysis, hydraul i c conductivity, and water retention.

ACKNOWLEDGMENTS

The f a c i l i t y described i n t h i s r e p o r t was b u i l t w i t h funding from t h e

Hanford S i t e P ro tec t i ve B a r r i e r Development Program sponsored by t h e U.S.

Department o f Energy. West i nghouse Hanford Company (WHC) prov ided personnel

t o a i d P a c i f i c Northwest Laboratory (PNL) i n design and cons t ruc t i on o f t he

f a c i l i t y . S. J. P h i l l i p s , J. F. Relyea, and N. R. Wing o f WHC ass i s ted i n

the e f f o r t t o complete t h i s f a c i l i t y i n a t i m e l y fashion. The i r hours o f

l abo r p l us he1 p f u l suggestions are g r e a t l y appreciated. Other s t a f f from

PNL who helped i n t h e cons t ruc t i on inc lude 0. B. Abbey, S. M. Goodwin,

M. J. Fayer, R. E. Hayden, and M. L. Rockhold. P. R. H e l l e r , and C. J. Kemp

provided add i t i ona l support i n 1 aboratory ana lys is and f i e l d moni tor ing.

Support and encouragement f o r t h i s e f f o r t a lso came from R. L. Skaggs and

C. T. K inca id o f PNL and J. Cammann and M. R. Adams o f WHC. F i n a l l y we wish

t o thank C. C. Morgan, T. L. Kogan, and the t e x t processing and e d i t i n g s t a f f

o f t he PNL Geosciences Department f o r t h e i r support.

ABBREVIATIONS

Units of Measure Hanford Site Terms

d day ALE Arid Lands Ecology (Reserve) di a diameter BWTF Buried Waste Test Facil ity cm centimeter HMS Hanford Meteor01 ogi cal Station cm3 cubic centimeter PNL Pacific Northwest Laboratory

g gram WHC Westinghouse Hanford Company h hour DOE U.S. Department of Energy k kilo (prefix, lo3)

kg ki 1 ogram kg/m3 kilogram per cubic meter kg-wt kilogram-weight L liter 1 b pound m meter

"-' g mi 1 1 igram mL milliliter mm millimeter

Y r year wt weight

CONTENTS

EXECUTIVE SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ACKNOWLEDGMENTS

1.0 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . 2.0 DESCRIPTION OF THE FACILITY . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . 2.1 FIELD LYSIMETER DESIGN

2.2 BARRIER TREATMENTS AND MATERIALS . . . . . . . . . . . . . . 2.2.1 Treatment 1: 1.5 m o f F ine S o i l . Ambient

. . . . . . . . . . . . P r e c i p i t a t i o n . and Vegeta t ion

2.2.2 Treatment 2: 1.5 m o f F ine S o i l . Ambient . . . . . . . . . . . . P r e c i p i t a t i o n . No Vegeta t ion

2.2.3 Treatment 3: 1.5 m o f F ine S o i l . Twice Average P r e c i p i t a t i o n . and Vegetat ion . . . . . . . . . . . .

2.2 - 4 Treatment 4: 1.5 m o f F ine Soi 1 . Twice Average P r e c i p i t a t i o n . and No Vegeta t ion . . . . . . . . . .

2.2.5 Treatment 5: 1.5 m o f F i ne S o i l w i t h Sur face Gravel Admix. Ambient P r e c i p i t a t i o n . and Vegeta t ion . . . . . . . . . . . . . . . . . . . . .

2.2.6 Treatment 6: 1.0 m o f F ine Soi 1. Ambient P r e c i p i t a t i o n . and Vegetat ion . . . . . . . . . . . .

2.2.7 Treatment 7: 1.5 m o f F ine S o i l . P r e c i p i t a t i o n . . . . . . . . . t o Breakthrough. and No Vegeta t ion

. . . . . . . . . . . . . . . . . . 2.2.8 Treatment Summary

. . . . . . . . . . . . . . . . . . . 3.0 INSTALLATION OF LYSIMETERS

3.1 FIELD LYSIMETER TEST FACILITY LEAK TESTS . . . . . . . . . . . . . . . . . . 3.2 PLACEMENT OF BASALT. GRAVEL. AND SAND LAYERS

. . . . . . . . . . . . . . . . 3.3 PLACEMENT OF FINE SOIL LIFTS

. . . . . . . . . 3.4 INSTRUMENTATION AND MEASUREMENT TECHNIQUES

. . . . . . . . . . . . 3.5 NEUTRON/GAMMA PROBE AND ACCESS WELLS

iii

v i i

1.1

2.1

2.1

2.2

3 . 6 TENSIOMETERS . . . . . . . . . . . . . . . . . . . . . . . . 3.9

3 .7 THERMOCOUPLES . . . . . . . . . . . . . . . . . . . . . . . 3 .10

3 . 8 THERMOCOUPLE PSYCHROMETER . . . . . . . . . . . . . . . . . . 3 . 1 1

3.9 ROOT OBSERVATION TUBES/RHIZOTRONS . . . . . . . . . . . . . 3.13

4.0 DETAILED LYSIMETER DESCRIPTIONS . . . . . . . . . . . . . . . . . 4 . 1

4 .1 DRAINAGE LYSIMETER 1 (D01-2) . . . . . . . . . . . . . . . . 4.2

4.2 DRAINAGE LYSIMETER 2 (D02-5) . . . . . . . . . . . . . . . . 4.2


4.4 DRAINAGE LYSIMETER4 (D04-1) . . . . . . . . . . . . . . . . 4.6

4 .5 DRAINAGE LYSIMETER 5 (D05-5) . . . . . . . . . . . . . . . . 4.6



4 .8 DRAINAGE LYSIMETER 8 (D08-2) . . . . . . . . . . . . . . . . 4 .10

4 .9 DRAINAGE LYSIMETER 9 (D09-7) . . . . . . . . . . . . . . . . 4 .10

4 .10 DRAINAGE LYSIMETER 1 0 (D10-4) . . . . . . . . . . . . . . . 4.10

4 .11 DRAINAGE LYSIMETER 11 ( D l l - 7 ) . . . . . . . . . . . . . . . 4 .10

4.12 DRAINAGE LYSIMETER 1 2 (D12-4) . . . . . . . . . . . . . . . 4 .16

4.13 DRAINAGE LYSIMETER 1 3 (D13-3) . . . . . . . . . . . . . . . 4.16

4 .14 DRAINAGE LYSIMETER 1 4 (D14-3) . . . . . . . . . . . . . . . 4.16

4 .15 WEIGHING LYSIMETER 1 (W01-1) . . . . . . . . . . . . . . . 4 . 1 6 .

4 .16 WEIGHING LYSIMETER 2 (W02-2) . . . . . . . . . . . . . . . 4 .20

4.17 WEIGHING LYSIMETER 3 (W03-3) . . . . . . . . . . . . . . . 4.20

4 .18 WEIGHING LYSIMETER 4 (W04-4) . . . . . . . . . . . . . . . 4.23

5.0 RAINFALL SIMULATOR . . . . . . . . . . . . . . . . . . . . . . . 5 . 1

6 . 0 HYDRAULIC PROPERTIES . . . . . . . . . . . . . . . . . . . . . . 6 . 1

6 . 1 MATERIALS . . . . . . . . . . . . . . . . . . . . . . . . . 6 . 1

. . . . . . . . . . . . . . . . . . . . . . . . . . 6.2 METHODS 6.4

6.2.1 Hydraul i c Conduc t i v i t y : Sa tu ra ted . . . . . . . . . 6.4

6.2.2 Hyd rau l i c Conduc t i v i t y : Unsaturated . . . . . . . . 6.5

. . . . . . . . . . . . . . . . . . . 6.2.3 Water Re ten t i on 6.6

. . . . . . . . . . . . . . . . . . . . . . . . . . 6.3 RESULTS 6.7

. . . . . . . . . . . . . . . . . . 7.0 FIRST YEAR TESTS AND RESULTS 7.1

. . . . . . . . . . . . . . . . . . . . . . . 7.1 WATER BALANCE 7.1

. . . . . . . . . . . . 7.1.1 Drainage Lysirneter Leak Tes ts 7.3

7.1.2 Lys imeter Drainage . . . . . . . . . . . . . . . . . 7.3

7.1.3 Water A d d i t i o n s by R a i n f a l l S imu la to r . . . . . . . . 7.5

7.1.4 Weight Changes Measured by Weighing Lys imeters . . . 7.5

. . . . . 7.1.5 Neutron Probe Measurements o f S o i l Mo i s tu re 7. 11

7.1.6 S o i l Mo i s tu re Tension Measurements . . . . . . . . . 7.17

. . . . . . . . . . . . . . . . . . . . 7.2 VEGETATION RESPONSE 7.17

. . . . . . . . . . . . . . 7.2.1 Vegeta t ion Estab l ishment 7.18

. . . . . . . . . . . . . 7.2.2 Phenol ogy and Observat ions 7.19

8.0 COLLECTION AND STORAGE OF DATA FOR THE FIELD LYSIMETER . . . . . . . . . . . . . . . . . . . . . . . . . . TESTFACILITY 8.1

. . . . . . . . . . . . . . . . . . . . . . 8.1 DATA COLLECTION 8 .1

8.2 FLTFDATABASE . . . . . . . . . . . . . . . . . . . . . . . 8.2

. . . . . . . . . . . . 8.2.1 Au toma t i ca l l y Co l l ec ted Data 8.5

. . . . . . . . . . . . . . 8.2.2 Manual ly C o l l e c t e d Data 8.5

. . . . . . . . . . . . . . . . . . . . . . . . . 9.0 RECOMMENDATIONS 9.1

. . . . . . . . . . . . . . . . . . . . . . . . . . . 10.0 REFERENCES 10.1

. . . . . . . . . . . . . . . . . . . . . . . . . . 11.0 BIBLIOGRAPHY 11.1

APPENDIX A . CHARACTERIZATION DATA FOR THE FIELD . . . . . . . . . . . . . . . . LYSIMETER TEST FACILITY A . l

x i i i

APPENDIX B - PROGRAM L IST INGS AND LABELS FOR F I E L D LYSIMETER TEST F A C I L I T Y DATALOGGERS . . . . . . . . . . . B . l

APPENDIX C - DIRECTORIES OF BARRIERS DATABASE . . . . . . . . . . . . C . l

FIGURES

Location of the Field Lysimeter Test Facility Adjacent to the Hanford Meteorological Station Between the 200 Areas on the Hanford Site . . . . . . . . . . . . . . . . . . . . . . . . 1.3

Schematic Drawing of the Field Lysimeter Test Facility Showing One-Hal f of the Para1 1 el Configuration of Lysimeters . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2

Plan View of the Field Lysimeter Test Facility and Treatment Descriptions for Each Lysimeter . . . . . . . . . . . 2.3

. . . . . . Drainage Lysimeter Construction. Top and Side Views 2.4

. . . . . . Weighing Lysimeter Construction. Top and Side Views 2.5

. . . . . . . Cutaway Drawing Showing Lysimeter Facil ity Design 2.6

Cutaway Schematic of Drainage Lysimeter Showing Rock and Soil Layers and Instrument Placement . . . . . . . . . . . . . . . . 2.7 Layering Sequence of Sands and Gravels in Weighing Lysimeters . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.6 Moisture Profile for Lysimeter D01-2 . . . . . . . . . . . . . . 4.3

Density Profile for Lysimeter D01-2 . . . . . . . . . . . . . . 4.3

Moisture Profile for Lysimeter D02-5 . . . . . . . . . . . . . . 4.4

Density Profile for Lysimeter D02-5 . . . . . . . . . . . . . . 4.4 Moisture Profile for Lysimeter D03-6 . . . . . . . . . . . . . . 4.5

Density Profile for Lysimeter D03-6 . . . . . . . . . . . . . . 4.5 Moisture Profile for Lysimeter 004-1 . . . . . . . . . . . . . . 4.7




Moisture Profile for Lysimeter D06-6 . . . . . . . . . . . . . . 4.9 Density Profile for Lysimeter D06-6 . . . . . . . . . . . . . . 4.9


4.14 Density Profile for Lysimeter D07-1 . . . . . . . . . . . . . . 4.15 Moisture Profile for Lysimeter D08-2 . . . . . . . . . . . . . . 4.16 Density Profile for Lysimeter D08-2 . . . . . . . . . . . . . . 4.17 Moisture Profile for Lysimeter D09-7 . . . . . . . . . . . . . . 4.18 Density Profile for Lysimeter D09-7 . . . . . . . . . . . . . . 4.19 Moisture Profile for Lysimeter D10-4 . . . . . . . . . . . . . . 4.20 Density Profile for Lysimeter D10-4 . . . . . . . . . . . . . . 4.21 Moisture Profile for Lysimeter Dll-7 . . . . . . . . . . . . . . 4.22 Density Profile for Lysimeter Dll-7 . . . . . . . . . . . . . . 4.23 Moisture Profile for Lysimeter D12-4 . . . . . . . . . . . . . . 4.24 Density Profile for Lysimeter D12-4 . . . . . . . . . . . . . . 4.25 Moisture Profile for LysimeterD13-3 . . . . . . . . . . . . . 4.26 Density Profile for Lysimeter D13-3 . . . . . . . . . . . . . . 4.27 Moisture Profile for Lysimeter D14-3 . . . . . . . . . . . . . . 4.28 Density Profile for Lysimeter D14-3 . . . . . . . . . . . . . . 4.29 Moisture Profile for Lysimeter W01-1 . . . . . . . . . . . . . . 4.30 Density Profile for Lysimeter W01-1 . . . . . . . . . . . . . . 4.31 Moisture Profile for Lysimeter W02-2 . . . . . . . . . . . . . . 4.32 Density Profile for Lysimeter W02-2 . . . . . . . . . . . . . . 4.33 Moisture Profile for Lysimeter W03-3 . . . . . . . . . . . . . . 4.34 Density Profile for Lysimeter W03-3 . . . . . . . . . . . . . . 4.35 Moisture Profile for Lysimeter W04-4 . . . . . . . . . . . . . . 4.36 Density Profile for Lysimeter W04-4 . . . . . . . . . . . . . . 5.1 Rainfall Simulator and Carriage at the Field Lysimeter Test

Faci 1 i ty . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.1 Map of the McGee Ranch Site . . . . . . . . . . . . . . . . . .

Soil Moisture Profiles in D09-7 and Dll-7 on November 4, 1987 and June 7, 1988. . . . . . . . . . . . . . . . 7.4

Twice Average Precipitation and Actual Water Applied from November 4, 1987 to June 21, 1988 . . . . . . . . . . . . . . . 7.6

Weighing Lysimeter W01-1 Calibration Results . . . . . . . . . . 7.9



Weighing Lysimeter W04-4 Cal i bration Results . . . . . . . . . . 7.10

Weighing Lysimeter Weight Record For W01-1 and W02-2 from Day 310 of 1987 to Day 166 of 1988 . . . . . . . . . . . . 7.12

Weighing Lysimeter Weight Record For W03-3 and W04-4 from Day 310 of 1987 to Day 166 of 1988 . . . . . . . . . . . . 7.12

Neutron Probe Calibration . . . . . . . . . . . . . . . . . . . 7.13

Soil Moisture Profiles in W01-1 as Measured by Neutron Probe . . 7.14

Gain or Loss in Water Content Measured by Neutron Probe. and Weighing Lysimeter . . . . . . . . . . . . . . . . . . . . . 7.14

Difference Between Neutron Probe and Weighing Lysimeter Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . 7.15

Storage Changes in Soil Moisture for All Lysimeters from November 4, 1987 to June 7, 1988 . . . . . . . . . . . . . . . . 7.16

Comparison of Soil Moisture Profile at McGee Ranch Site and at Field Lysimeter Test Facility . . . . . . . . . . . . . . . 7.20

Comparison of Phenol ogical Development of a ) Bromus tectorum and b) Poa secunda at McGee Ranch and Field Lysimeter Test Facility. . . . . . . . . . . . . . . . . . . . . . . . . . 7.22

Data Flow from Collection at the Field Lysimeter Test Facility Through Transmission to Laboratory . . . . . . . . . . 8.3

Detailed Description of Data Flow, Manipulation, and Final Storage in the Field Lysimeter Test Facility Database . . . . . 8.4

Organization of the Field Lysimeter Test Facility Database . . . 8.6

. . . . . . 8 . 4 Graph Showing S o i l Mo is tu re P r o f i l e f o r Lysimeter Dl 8 . 1 2

A . l P roc tor Densi ty . . . . . . . . . . . . . . . . . . . . . . . . A.32

A.2 P a r t i c l e Size Ana lys is FLTF D 0 1 - 0 2 . . . . . . . . . . . . . . . A.33

A.3 Cal i b r a t i o n Data f o r t h e Seaman Nuclear Probe . . . . . . . . . A.34

B . 1 Example o f Datalogger Program f o r F i e l d Lysimeter Test F a c i l i t y . . . . . . . . . . . . . . . . . . . . . . . . . . . . B.2

B.2 Example o f t heTERMSta t i on F i l e andTERMMoni tor ing Options . . B.8

B.3 Example o f t he Parameters Set i n t h e TELCOM S t a t i o n F i l e . . . . B.9

TABLES

Water Added t o Lys imeters a t t h e F i e l d Lys imeter Tes t F a c i l i t y f rom November 5, 1987, Through June 21, 1988 . . . . . 5.3

S o i l L i f t Depths f o r t h e Drainage Lys imeters a t F i e l d Lys imeter Test F a c i l i t y . . . . . . . . . . . . . . . . . . . . 6.3

Tex tu ra l Ana l ys i s o f 16 F i e l d Lys imeter Tes t F a c i l i t y Samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.4

Hydraul i c Conduc t i v i t y , Sa tu ra ted Water Content, and S a t u r a t i o n R a t i o . . . . . . . . . . . . . . . . . . . . . . . . 6.7

C u r v e - F i t t i n g Resu l ts f o r F i e l d Lys imeter Test F a c i l i t y Labora to ry Water Re ten t i on and Hyd rau l i c C o n d u c t i v i t y Data . . . 6.8

Water Re ten t ion Val ues f o r Se lec ted F i e l d Lys imeter Tes t F a c i l i t y S o i l Samples Vo lumet r i c Water Content . . . . . . . . . 6.9

C X 1 ( R e l a t i v e Humid i t y Sensor Data f o r Composite F i e l d Lys imeter Tes t F a c i l i t y Samples) . . . . . . . . . . . . . 6.10

Water Balance f o r t h e F i e l d Lys imeter Test F a c i l i t y f rom November 1, 1987 t o June 21, 1988 . . . . . . . . . . . . . . . 7.2

Cumulat ive Drainage f rom Lys imeters D09-7 and D l l - 7 . . . . . . 7.4

Water Accumulat ion Needed t o Achieve Twice Average P r e c i p i t a t i o n . . . . . . . . . . . . . . . . . . . . . . . . . 7.6

To ta l Water D e l i v e r y f rom P r e c i p i t a t i o n and A p p l i c a t i o n . . . . 7.7

S o i l Mo i s tu re Tension . . . . . . . . . . . . . . . . . . . . . 7.17

D e f i n i t i o n s o f 14 Phenophases f o r Shor t Grass P r a i r i e Species A f t e r French and Sauer (1974) . . . . . . . . . . . . . 7.21

Parameters Measured a t F i e l d Lys imeter Test F a c i l i t y and Method o f Data C o l l e c t i o n . . . . . . . . . . . . . . . . . . . 8.2

I n i t i a l I n -P lace Leak Tes ts o f F i e l d Lys imeter Tes t F a c i l i t y Lys imeters i n A p r i l 1987 . . . . . . . . . . . . . . . A . l

Drainage Lys imeter Leak Tests . . . . . . . . . . . . . . . . . A.4

Weights o f M a t e r i a l L i f t s Used i n Each Lys imeter . . . . . . . . A.5

Fac to ry C a l i b r a t i o n Values f o r Thermocouple Psychrometer . . . . A.6

x i x

A . 5 Summary o f Dens i t y and Mo i s tu re I n f o r m a t i o n f o r Each . . . . . . . . . . . . . . . . . . . . . . . Drainage Lys imeter A.7

. . . . . A . 6 Mois tu re and Dens i t y Data f o r t h e Weighing Lys imeters A.27

A . 7 Summary o f Tex tu ra l Ana l ys i s f o r FLTF Draomage Lys imeters . . . A.29

. . . . . . . . A.8 Example o f Data Table f o r P a r t i c l e S i ze Ana l ys i s A.30

1.0 INTRODUCTION

Large volumes of radioactive waste currently are buried at the Hanford Site in a variety of near-surface disposal facilities ranging from simple soi 1 -covered trenches to mi 11 ion-gal 1 on tanks. Permanent disposal options include exhuming the waste and placing it in a deep geologic repository, in situ immobilization (i .e., in situ vitrification), and isolation from environmental forces (i .e., barriers). Placing protective barriers over waste sites has been proposed as an engineering a1 ternative to exhuming wastes and relocating them. The Record of Decision (53 FR 12449-53) on disposal of Hanford defense high-level, transuranic and tank wastes commits to placement of a protective barrier over low-activity double-shell tank waste that has been disposed of in near-surface grout vaults. These protective barriers are being designed to 1 imit plant and animal intrusion and to restrict water infiltration to levels below prescribed limits. By controlling the infiltration of water, the barrier can also control the release and transport of radionuclides through the vadose zone to ground water. These barriers will be essential to long-term (10,000-year design life) protection of the envi- ronment without monitoring, maintenance, or active institutional controls.

Westi nghouse Hanford Company (WHC) i s formul ating barrier performance standards based on needs specified in the Disposal of Hanford Defense Hiqh- Level , Transurani c and Tank Wastes Fi nal Envi ronmental Impact Statement (USDOE 1987). Important technical considerations include selecting, eval u- at i ng , and demonstrating barrier materi a1 s, barrier systems, and empl acement methods that will meet the requirements of the U.S. Department of Energy (DOE), U.S. Environmental Protection Agency (EPA) , and Washington State. The Hanford Site Protective Barrier Development Program was developed jointly by WHC and the Pacific Northwest Laboratory (PNL) with objectives to test barrier design concepts and to demonstrate barrier designs that meet established performance criteria.' Plans are now being made to evaluate specific barrier designs using lysimeters and small - and 1 arge-scal e field plots.

Individual tasks of the program address specific issues related to barrier design and performance. The program tasks include assessments of 1) biointrusion control, 2) water infiltration control, 3) erosion control,

4) barrier construction materials, 5) physical stabil ization (subsidence), 6) human intrusion control, 7) field monitoring and model validation, 8) natural analogues, and 9) climate change effects. In addition, interactions between environmental and design factors that may cause disruption or degradation of the barrier are also addressed. Specifically, the effects of biointrusion on water infiltration will be studied, as well as the effects of erosion control (i.e., surface gravel additions) on plant growth and water infiltration and storage. These program tasks are presented in detail in the Protective Barrier and Warninq Marker System Develo~ment Plan (Adams and Wing 1986) .

The Field Lysimeter Test Facility (FLTF) was built during FY 1987 near the Hanford Meteorological Station (HMS) (see Figure 1.1) to evaluate how well the barrier system will limit water infiltration. The facility contains 14 drainage lysimeters and 4 weighing lysimeters. This facility will provide data for direct comparison of key barrier components, and specific data sets will be used to calibrate and test models that will accurately predict long- term barrier performance.

The amount of yearly precipitation not removed by evapotranspiration and available to move through waste sites at Hanford is at present unknown. The lysimeters used at the FLTF will allow direct measurement of water that passes through the barrier system. Using this collected water, we can measure the effectiveness of the barrier system under the environmental conditions experienced during the observation period.

Although the main objective of the lysimeter facility is to assess the effectiveness of selected protective barriers in controlling water infiltration, it will also be used to evaluate the impact of selected engineering changes in the barriers, such as varying the soil thickness and adding gravel at the soil surface. Using gravel to control erosion is one of the current design features that will require testing to assess its impact on the overall effectiveness of the system.

r ------- 7 i- '

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FIGURE 1.1. Locat ion o f t h e F i e l d Lys imeter Test F a c i l i t y (FLTF) Adjacent t o t h e Hanford Meteoro log ica l S t a t i o n Between t h e 200 Areas on t h e Hanford S i t e

This report documents the construction of the facility and describes in

detail the backfilling and instrumentation of each lysimeter. In addition,

results of the initial infiltration tests and laboratory determinations of

soil properties are presented here.

2.0 DESCRIPTION OF THE FACILITY

The FLTF i s l o c a t e d on t h e Hanford S i t e near t h e HMS between t h e

200-West and 200-East Areas (F igu re 1.1) (N 44200 and W 69300 Hanford S i t e

coord ina tes ) . The f a c i l i t y i s approx imate ly 150 m west-southwest o f t h e

main ins t rument tower a t t h e HMS. The s i t e was chosen because o f i t s

p r o x i m i t y t o t h e major waste management areas (200 East and 200 West) a t

Hanford and t h e qua l i t y -assu red c l i m a t e s t a t i o n f rom which HMS da ta a re

ava i 1 ab l e.

2.1 FIELD LYSIMETER DESIGN

P a c i f i c Northwest Laboratory and WHC s t a f f j o i n t l y developed a concep-

t u a l des ign o f t h e FLTF and worked w i t h Ka i se r Engineers Hanford Company t o

f i n a l i z e t h e design. Th i s f a c i l i t y i s be ing used as bo th a research and

demonstrat ion f a c i l i t y f o r t h e b a r r i e r program. The FLTF i s cons t ruc ted

f rom a p a r a l l e l s e t o f s t e e l tanks b u r i e d a t grade. F igure 2.1 shows a

schematic drawing o f one -ha l f o f t h e FLTF. The eng ineer ing des ign drawings

f o r t h e f a c i l i t y a re con ta ined i n a s e t o f drawings numbered H-6-5324 through

H-6-5333 on f i l e w i t h WHC. These drawings i n c l u d e d e t a i l s o f l y s i m e t e r con-

s t r u c t i o n and t h e placement o f t h e l y s i m e t e r s i n t o a completed f a c i l i t y .

F igures 2.2 through 2.5 i l l u s t r a t e t h e o v e r a l l des ign fea tu res . I n a d d i t i o n ,

F i gu re 2.2 l i s t s t h e l y s i m e t e r s by number and s p e c i f i e s t h e t reatment . The

number f o l l o w i n g t h e dash i n d i c a t e s t h e t rea tment i n t h a t l y s i m e t e r .

The FLTF con ta ins bo th dra inage and weigh ing l y s ime te rs . The measure-

ment c a p a b i l i t i e s o f these two types o f l y s i m e t e r s were descr ibed p r e v i o u s l y

(Gee and Jones 1985) and appear t o be s u i t a b l e t o t e s t b a r r i e r performance

f o r water i n f i l t r a t i o n c o n t r o l . The dra inage l y s i m e t e r s a re designed t o con-

t a i n a b a r r i e r w i t h a f i x e d volume (2 m d i a x 3 m deep) i n which water s t o r -

age changes a re measured us ing a neu t ron probe, a gamma probe, and p e r i o d i c

s o i l sampling. Drainage i s measured d i r e c t l y by c o l l e c t i n g water f rom a

d r a i n p o r t a t t h e bottom o f t h e l y s i m e t e r (F i gu re 2.6). The weigh ing l y s i m -

e t e r s i s o l a t e a s o i l volume (1.5 m x 1.5 m x 1.6 m deep) and generate a con-

t i nuous r e c o r d o f weight changes, which, when supplemented w i t h phys i ca l

observat ions, can be used t o es t imate p r e c i p i t a t i o n , evapo t ransp i ra t i on , and

I Weighing Lysimeter \ I

FIGURE 2.1. Schematic Drawing o f t h e F i e l d Lys imeter Tes t F a c i l i t y Showing One-Half o f t h e Para1 l e l C o n f i g u r a t i o n o f Lys imeters

s to rage changes. I n a d d i t i o n , d ra inage can a l s o be measured d i r e c t l y by

c o l l e c t i n g wate r f r om a d r a i n p o r t a t t h e bot tom o f each weigh ing l y s i m e t e r .

2.2 BARRIER TREATMENTS AND MATERIALS

The b a r r i e r systems t o be t e s t e d i n t h e FLTF were se lec ted p r i m a r i l y t o

1) demonstrate t h e e f f e c t i v e n e s s o f a m u l t i l a y e r b a r r i e r i n c o r p o r a t i n g a

p o r e - s i z e d i s c o n t i n u i t y t o l i m i t unsa tu ra ted f low, 2 ) c o l l e c t i n f o r m a t i o n on

b a r r i e r performance under n a t u r a l and e leva ted r a i n f a l l cond i t i ons , and

3 ) examine e f f e c t s o f v e g e t a t i o n on b a r r i e r performance.

P r e c i p i t a t i o n ( t h e amount o f wa te r [ r a i n o r snow] added t o t h e s o i l p r o -

f i l e ) and e v a p o t r a n s p i r a t i o n ( t h e amount o f water removed through bare s o i l

evapora t ion and p l a n t t r a n s p i r a t i o n ) a t t h e su r f ace o f t h e b a r r i e r system a re

i n p u t s and ou tpu ts , r e s p e c t i v e l y . When p r e c i p i t a t i o n (P) i s l a r g e r than

e v a p o t r a n s p i r a t i o n (ET), s o i l wa te r s to rage increases, and, converse ly , when

ET i s l a r g e r than P, s o i l wa te r decreases. The amount o f water t h a t can be

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FIGURE 2 - 3 . Drainage Lysimeter Construct ion, Top and Side Views

Top View

Side View

FIGURE 2 . 4 . Weighing Lysirneter Construct ion, Top and Side Views

Access Tubes

Thermocouples

0.04- to O.OSrn-dia. Railroad Ballast

Thermocouples

FIGURE 2.6. Cutaway Schematic o f Drainage Lys imeter Showing Rock and S o i l Layers and Ins t rument Placement

s to red i s d i r e c t l y r e l a t e d t o depth o f t h e s o i l and i t s phys i ca l cha rac te r -

i s t i c s , such as h y d r a u l i c c o n d u c t i v i t y , water r e t e n t i o n , t e x t u r e , and

l a y e r i n g .

A l l f i n e s o i l used i n t h e l y s i m e t e r s was ob ta ined f rom an area on t h e

Hanford S i t e g e n e r a l l y r e f e r r e d t o as t h e McGee Ranch (see F i g u r e 1.1). The

c h a r a c t e r i z a t i o n o f these f i n e s o i l s i s descr ibed i n Las t e t a l . (1987) and

i n t h i s document. Adequate s o i l t h i ckness i s impor tan t f o r t h e b a r r i e r

system to operate effect ively; i f the soi l layer thickness i s insuff ic ient t o

s tore yearly precipitation, the soil a t the bottom of the soi l layer may

saturate and drain into lower rock layers. Conversely, i f the soil layer i s

too thick, water may move below the root zone, which will eventually

saturate soil a t the interface and cause drainage. For typical arid s i t e

conditions, the depth of soil that will be effect ive i s thought t o be between

1.5 and 2 m. Preliminary modeling e f fo r t s using character is t ics for a s i l t

loam soil indicate 1.5 m of soil as sui table . Over 10,000 years, a 1.5-m

soi l thickness may erode; therefore, a 1-m soil depth i s being examined to

determine i f t h i s thickness i s s t i l l an effect ive barr ier . To minimize the

chance of erosion, the addition of an admix of gravel in the top 20 cm was

proposed. This admix i s being tested in D02-5 and D05-5 for i t s influence on

water storage and subsequent barrier effectiveness.

Barrier performance i s controlled by the interaction of several dynamic

and s t a t i c processes associated with climate, soil properties, and plant

cover character is t ics . All of these variables have a range of values. To

t e s t the effectiveness of a barr ier system, i t i s necessary to select d is -

crete values for each variable, then evaluate the barr ier ' s performance. I t

i s also important t o note the interaction between variables; for example,

increased precipitation may cause increased plant growth or increased gravel

cover might cause increased surface moisture, which would, in turn, enhance

plant growth. The complexity of t h i s system and the large number of var i-

ables affecting the system's performance preclude a complete factori a1 exper-

iment evaluating each variable and i t s interaction with every other variable.

However, additional t e s t s with 100 additional b u t smaller (0.3-m-dia) eco-

nomical tube-type lysimeters are under way which will provide support in

analyzing the complex variables that affect water in f i l t r a t ion and wind ero-

sion interactions on barrier performance a t the Hanford Si te .

Information on barr ier performance i s collected from treatments tha t

represent a f i n i t e and limited se t of environmental conditions. I t i s

expected that a f t e r a 5- to 7-year period of tes t ing, conclusions can be made

regarding the performance of selected barr ier designs. Test cases, as moni-

tored in the lysimeters, include a wide range of conditions (e.g. , precipi-

ta t ion, surface cover, and soil depth) so that bounding cases for barr ier

drainage can be evaluated. From these test cases and monitoring efforts, model calibration and validation data sets can be formulated with which to validate UNSAT-H (Fayer, Gee, and Jones 1986) and other computer codes used to predict barrier performance.

Observations of barrier performance coupled with 1 ong-term model simulations will allow optimization of the barrier design. As this optimization effort proceeds, it may be worthwhile to modify treatments in the FLTF to collect information on specific aspects of barrier performance. Past experience with other lysimeter systems at Hanford has shown this type of research

facil ity to be useful far beyond the original funding project or research effort.

Continuity of measurements is important to the success of the project. During the next 5 to 7 years, we expect that much will be learned from these

tests about protective barrier performance at Hanford. Seven treatments were selected for evaluation in the FLTF. These treatments were selected to

represent the environmental conditions most likely to occur and possible worst-case conditions. Figure 2.2 shows which lysimeters contain which treatments and documents the seven treatments associated with the 18 lysimeters at the FLTF.

Treatments 1, 2, 3, and 4 are used in a 2 x 2 factorial design to distinguish effects of precipitation and soil cover. Precipitation is divided into ambient and twice average. Soil cover is divided into vegetated and nonvegetated. These four treatments are replicated twice in drainage

lysimeters and once in weighing lysimeters, using a total of 12 lysimeters.

Two additional main-effect treatments (using four additional lysimeters), with other variables held constant, consist of I ) a comparison of bare soil with a soil containing 15% gravel by weight in the top 20 cm and 2) a comparison of a 1.0- versus 1.5-m-thick soil profile.

The seventh treatment (using two lysimeters) is used to study the

behavior of a barrier system when sufficient water is applied to cause fail-

ure. Over the short term, this treatment will also provide information on soil hydraulic conductivities and field capacity. After short-term tests are completed, vegetation will be planted on the two lysimeters to indicate how

rapidly these plants can use the water in a very wet profile and how rapidly

they can return soil water storage to levels equal to those observed in treatments receiving ambient 'precipitation.

2.2.1 Treatment 1: 1.5 m of Fine Soil, Ambient Precipitation, and Veqetation

This treatment represents a barrier design that incorporates features of adequate soil-water storage capacity and optimizes soil water loss through

evapotranspiration. The barrier system uses 1.5 m of fine soil to store water, receives ambient precipitation, and is vegetated to increase evapo- transpirational losses. Treatment 1 serves as the primary demonstration of

the effectiveness of the barrier design.

Replication: Weighing lysimeter 1 and drainage lysimeters 4 and 7 (W01-1, D04-1, D07-1).

2.2.2 Treatment 2: 1.5 m of Fine Soil, Ambient Precipitation, No Veqetation

This treatment represents the optimized barrier design without vegetation, as presented in Treatment l. Under ambient precipitation levels, the

barrier should function for several years even in the absence of vegetation. An actual barrier might experience this condition only after range fires or extended droughts. Although this is a transient condition, the lack of vegetation will 1 i kely have a significant impact on water balance and must be documented.

Replication: Weighing lysimeter 2 and drainage lysimeters 1 and 8 (W02-2, D01-2, 008-2).

2.2.3 Treatment 3: 1.5 m of Fine Soil, Twice Averaqe Precipitation, and Veqetation

This treatment represents the same optimized barrier design presented in Treatment 1, except the average precipitation is doubled. The vegetation

will likely increase as the available water increases, but it will take

several years for this vegetation to reach the actual total biomass that could be supported under heavy rainfall conditions.

Replication: Weighing lysimeter 3 and drainage lysimeters 13 and 14 (W03-3, 013-3, D14-3).

2.2.4 Treatment 4: 1.5 m of Fine Soil, Twice Averaqe Precipitation, and No

Veqetation

This treatment represents the worst-case condition applied to the bar-

rier system. Treatment 4 receives twice-average precipitation and has no

vegetation to remove stored water. Under these conditions some drainage may occur. The elevated rainfall should cause this treatment to reach steady-

state condition much more quickly than lysimeters receiving only natural pre cipitation. The application rate of additional precipitation is discussed

in Section 7.0.

Replication: Weighing lysimeter 4 and drainage lysimeters 10 and 12 (W04-4, D10-4, D12-4).

2.2.5 Treatment 5: 1.5 m of Fine Soil with Surface Gravel Admix, Averaqe Precipitation, and Veqetation

Treatment 5 is identical to Treatment 1 except the surface has gravel (22% by weight in the top 20 cm) incorporated to minimize erosion. Using this treatment, we wi 11 examine whether surface gravel causes an unacceptable increase in water storage. The addition of gravel mulch may also affect seedling establishment, species composition, density, and community struc- ture. If large differences occur in the vegetation community compared to other treatments containing vegetation, the vegetation may be removed from this treatment. This treatment would then be compared with Treatment 2, which has no vegetation.

Replication: Drainage lysimeters 2 and 5 (D02-5, D05-5).

2.2.6 Treatment 6: 1.0 m of Fine Soil, Ambient Precipitation, and Veqetation

Lysimeters containing this treatment will be used to evaluate how the

depth of the fine soil layer affects barrier performance. Under postulated

harsh environmental conditions, the soil surface may erode and reduce the

soil available for water storage. The removal of 0.5 m of soil is believed to represent a severe erosion scenario during the 10,000-year operation of

the barrier system. In some cases, UNSAT-H computer simulations have indicated better barrier performance with 1 m of soil than with 1.5 m of soi 1 (Fayer 1987). Because the water is stored closer to the surface, it is more readily lost to evapotranspiration and the 1-m barrier appears to be more effective. This is true only when the 1-m soil storage capacity is not exceeded. This treatment will help to demonstrate how we1 1 the barrier functions at reduced soil thickness.

Replication: Drainage lysimeters 3 and 6 (D03-6, D06-6).

2.2.7 Treatment 7: 1.5 m of Fine Soil, Precipitation to Breakthrouqh and No Veqetation

This treatment examines the physical behavior of the barrier system when enough water is added to the system to cause transmission of water through the barrier. Lysimeters receiving Treatment 7 will be covered to prevent evapotranspiration. Hydraulic conductivities, water contents, and gradients in potential will also be measured and used in model validation. As drainage becomes insignificant, soil profile moisture will be measured to determine storage capacity of the soil. After drainage studies are completed, this treatment will be identical to Treatment 1, except that the soil profile will be much wetter. The surface will be uncovered and vegetation introduced; this will demonstrate how fast the barrier system can recover from an extreme, catastrophic rainfall or flooding event.

Replication: Drainage lysimeters 9 and 11 (D09-7, Doll-7).

2.2.8 Treatment Summary

The seven treatments are specific to water infiltration. Although these tests address issues related to interaction effects, such as how gravel-admix affects plant growth and water storage, how soil loss affects water storage and plant growth, and how enhanced rainfall affects vegetation and water storage, the treatments do not address issues related to animal intrusion. Animal intrusion testing is being conducted in a companion field study using similar soil cover designs (Adams and Wing 1986).

3.0 INSTALLATION OF LYSIMETERS

Excavation and construction of the FLTF was accomplished between

November 1986 and February 1987. Figure 2 . 2 shows the para1 1 el configuration

of the lysimeters, and the lysimeter and treatment number assigned t o each

tank. During March of 1987, the f i n e s o i l s designated fo r use in the bar r ie r

system were excavated from the McGee Ranch s i t e and del ivered t o the FLTF s i t e . The soi l stock p i l e was mixed once using a large f ron t loader. The

water content of the so i l stock p i l e was increased from 8% t o 14% by weight

by the use of spr inklers . This moisture content i s close t o optimum f o r

compaction (see Figure A. 1 in the Appendix). Preliminary leak tes t ing of the

f a c i l i t y was completed during April 1987, and the lysimeters were ins t ru -

mented and backfi l led during May and June of 1987.

This section provides d e t a i l s on how lysimeters were leak tes ted ,

describes backfi 11 ing procedures, and documents the instrumentation placed in

each tank. The material layers in the drainage lysimeters were the same fo r

a l l treatments, except f o r Treatment 6 , which included only 1 m of f i ne s o i l .

The depths of each material 1 ayer and location in reference t o the geo tex t i l e

layer are shown in Figure 2.6.

3.1 FIELD LYSIMETER TEST FACILITY LEAK TESTS

Before shipment from the factory t o the t e s t s i t e , the tanks and boxes

used fo r the 18 lysirneters were f i l l e d with water and leak tes ted by the

manufacturer with 60 cm of standing water. Inspection a t the factory indi-

cated t ha t a l l tanks bottoms were sealed ( i . e . , did not leak under a 60-cm water head).

A cement grout was injected underneath each tank t o form a sol id support

under the tank bottom. This in ject ion resul ted in a minor bow (center of

tank f loor raised as much as 0.5 cm) in the tank f loor . A second f i e l d leak

t e s t was performed t o confirm tha t no major tank damage had occurred during

construction. Before the lysirneters were tes ted fo r leaks, the bottom and

inside (up t o heights of 20 cm) of each drainage tank and weighing lysimeter

box were coated with approximately a 3-mil-thick layer of coa l - ta r epoxy.

This precaut ion was taken t o seal t he bottoms against r u s t i n g , which might

cause p inho le l eaks t h a t could a f f e c t drainage.

The l ys ime te rs were f i l l e d w i t h water on A p r i l 16 and 17, 1987, and one

l y s i m e t e r was r e f i l l e d on A p r i l 20, 1987, because o f a l e a k i n g hose. A l l

l y s ime te rs were dra ined on A p r i l 24, 1987.

Each dra inage l y s i m e t e r was charged w i t h water and a l lowed t o d r a i n

f r e e l y be fore beginning the l e a k t e s t . Th is ensured t h a t any water t h a t

might be r e t a i n e d i n t h e tanks would no t a f f e c t t he r e s u l t s o f t h e l e a k t e s t .

A known amount o f water (weighed us ing a ~ a u t e r ( ~ ) 120-kg scale) was then

added t o cover t h e bottom o f each l ys ime te r . The depth o f water ranged from

about 1 t o 11 cm o f s tanding water because o f the s lop ing bottom. A f t e r

7 days, t h i s water was dra ined i n t o carboys and reweighed t o determine

whether t h e i n i t i a l and f i n a l weights d i f f e r e d s i g n i f i c a n t l y . Dur ing the

w a i t i n g per iod , t h e tops o f t he l ys ime te rs were covered w i t h a heavy, po l y -

v i n y l c h l o r i d e (PVC)-reinforced p l a s t i c sheet ing t o minimize evaporat ion.

The dra ined water was approximately 99% o f t he i n p u t water on average. Two

tanks re tu rned 98% o f t he i n p u t water. I n two cases, t h e re tu rned water was

s l i g h t l y g r e a t e r than t h e i n p u t water i n d i c a t i n g measurement e r r o r o r poss i -

b l y s l i g h t f l e x i n g o f t h e bottom o f the empty l ys ime te r (see Appendix A).

Th is t e s t suggested t h a t , w i t h i n the e r r o r o f t he measurement and p rope r l y

accounting f o r evaporat ion losses, t he re were no leaks. Subsequent t e s t s t o

evaluate leakage were performed a f t e r t he l ys ime te rs were f i l l e d and are

discussed i n Appendix A.

3.2 PLACEMENT OF BASALT, GRAVEL, AND SAND LAYERS

M a t e r i a l s were placed i n t he l ys ime te rs i n a systematic fashion. Basa l t

r i p r a p was p laced i n t h e bottom, fo l lowed by a sequence o f graded grave ls and

sands and f i n a l l y covered by f i n e s o i l . This "graded" f i l t e r was designed t o

prevent f i n e s o i l s from s i f t i n g i n t o the r i p r a p .

(a ) Sauter i s a t r a d e name o f t he M e t t l e r Instrument Co., Heightstown, New Jersey.

3.2

As mentioned above, t h e f l o o r s o f t h e l y s i m e t e r s and approx imate ly 10 cm

o f t h e a d j o i n i n g w a l l were coated w i t h c o a l - t a r epoxy be fo re any m a t e r i a l s

were p laced i n t h e l y s ime te rs . To avo id mar r i ng t h i s coa t ing , a l a y e r o f

washed b a s a l t r i p r a p ( i . e . , b a s a l t r o c k g r e a t e r than 10 cm i n d i a ) was care-

f u l l y p laced by hand on t h e bottom o f each tank. Then, t h e 14 dra inage

tanks were f i l l e d w i t h about 1 m o f water, and b a s a l t r o c k was dropped i n t o

t h e t a n k us ing a backhoe. The backhoe was ab le t o l owe r i t s bucket i n t o t h e

t ank so t h a t t h e rocks dropped 2 m t o t h e bottom o f t h e tank. The water p ro -

v i ded a cushion t o min imize bouncing and s c r a t c h i n g o f t h e r i p r a p m a t e r i a l

aga ins t t h e c o a t i n g on t h e bottoms o f t h e tanks. A f t e r t h e l a r g e b a s a l t

r i p r a p was brought t o t h e c o r r e c t l e v e l o f 195 cm (145 cm i n t h e l y s i m e t e r s

r e c e i v i n g Treatment 6 w i t h o n l y 1 m o f f i n e s o i l ) f rom t h e t o p o f t h e tank,

0.04- t o 0.05-m-dia r a i l r o a d b a l l a s t was p laced i n t h e n e x t l e v e l .

The 0.04- t o 0.05-m-dia r a i l r o a d b a l l a s t was loaded w i t h t h e ~ o b c a t ( ~ )

loader ; then t h e l o a d e r w i t h d r i v e r and m a t e r i a l was weighed on a 9080 kg

(20,000 l b ) c a p a c i t y p l a t f o r m scale. The m a t e r i a l was p laced i n t h e l y s i m -

e t e r us i ng t h e Bobcat, and t h e weigh ing and placement process cont inued w i t h

p e r i o d i c check ing f o r t a r e weight . The mean weight o f 0.04- t o 0.05-m-dia

r a i l road b a l l a s t necessary t o b r i n g t h e l e v e l t o 180 cm f rom t h e t o p o f t h e

t ank was 831 kg. The "graded" f i l t e r l a y e r i nc l uded 1.9-cm g rave l , 0.95-cm

t o 1.27-cm pea g rave l , and No. 8 and No. 20-30 sands. The 1.9-cm g rave l , pea

g rave l , and No. 8 and No. 20-30 sands were s i m i l a r l y weighed us ing t h e Bobcat

l o a d e r and p l a t f o r m scale. The mean we igh ts o f each o f these l i f t s and t h e

d i s tance f rom t h e t o p o f t h e l i f t t o t h e t o p o f t h e t ank (numbers i n

parentheses r e f e r t o Treatment 6) a re 1 i s t e d be1 ow:

1.9-cm g rave l 617 kg 170 cm (140)

pea g rave l (0.95 cm) 258 kg 165 cm (135)

No. 8 sand (0.24 cm) 235 kg 160 cm (130)

No. 20-30 sand (0.08 t o 0.06 cm) 226 kg 155 cm (125)

The ac tua l weights o f m a t e r i a l used i n each' l y s i m e t e r a re presented i n

Table A.2, Appendix A.

(a ) Bobcat i s a t r a d e name o f t h e Clark-Mel roe Co., Gwinner, South Dakota.

3.3

Each of these mater ia ls was dumped i n to the tank and then ca re fu l ly leveled before t he next l ayer was pl aced. The neutron/gamma probe por ts were s e t in the 0.04- t o 0.05-m-dia ra i l road ba l l a s t and held in place during the process by using a j i g . This helped t o ensure t h a t the access pipes remained equidis tant from one another.

The f i r s t drainage tank t h a t was backf i l led was an exception t o t h i s f i l l i n g sequence. Lysimeter D09-7 was f i l l e d using s l i g h t l y d i f f e r en t methods and mater ia ls . Originally, we assumed t ha t we would be able t o use basal t and gravels from the Gable Mountain s tockpi les . These mater ia ls , however, when delivered contained too much so i l and debr is and could not be washed well enough f o r use in the tanks. Lysimeter D09-7 was f i l l e d with hand-washed and hand-placed basal t from Gable Mountain t o a level 185 cm below the top of the tank. Next, a 10-cm l i f t of hand-picked 0.04- t o 0.05-m-dia r a i l r oad ba l l a s t was placed, bringing the l i f t level t o 175 cm from the top of t he tank. Then a 5-cm l i f t of 1.9-cm gravel-s ize basa l t from Gable Mountain was placed in the tank, bringing the level up t o 170 cm. The layers of pea gravel and sand were placed in lysimeter D09-7 as described f o r the other lysimeters. Because t h i s procedure was too labor in tensive , washed mater ia ls were procured from an o f f s i t e contractor . All o ther lysimeters used o f f s i t e basa l t mater ia ls (obtained from a borrow p i t located in Kennewick, Washington).

I t i s important t o note t h a t clean, washed materials wil l not be required fo r construction of an actual b a r r i e r ; we have used clean mater ia ls t o simplify the measurement of drainage i n the lysimeters. The basa l t and rock layers have a small but s i gn i f i c an t water storage capacity t h a t must be. considered because we a re attempting t o measure drainage volumes of approximately 1200 cm3 (1.2 L ) . This drainage volume i s equivalent t o a water con- t e n t change of 0.04 vol% in the basa l t l ayer . For t h i s reason, we pre-wet the layers of ba sa l t , rock, and sand t o prevent storage of any water draining out of the so i l l ayer . We wet these l ayers by at taching a f i l l hose t o the

bottom drain and in jec t ing water un t i l i t was observed on top of the geo- t e x t i l e l ayer ; the hose was then removed and each tank allowed t o drain. Excessive f i ne s i n the basa l t and rock mater ia ls would tend t o increase s t o r - age of water in these l ayers , so mater ia ls were washed before use. Samples

of a1 1 of these materials have been placed in 55-gal drums and will be stored

for any future characterization work that may be needed.

After the l a s t sand layer had been leveled, a geotextile l iner (Mirafi

1000, Mirafi Inc., Charlotte, North Carolina) was placed on top of the sand

to prevent any f ine so i l s from s i f t ing into the sand layer. The geotextile

i s a black, woven, polypropylene material. An e l e c t r i c heat knife was used

to cut the c i rc les of geotextile to seal the edges and prevent fraying of the

materi a1 . These c i rc les were cut t o 215 cm in di a t o a1 1 ow 5 t o 7 cm of geo-

t e x t i l e t o l i e against the lysimeter wall. The geotextile was attached t o

the lysimeter walls with s i l a s t i c caulking t o hold the l ine r in place during

backfilling. Two major reasons support the use of a geotextile. F i rs t , the

sand and gravel layers are thinner than would be used in an actual construc-

tion (the layers are present to create the pore s ize discontinuity and as a

backup to the geotextile) and second, the geotextile prevents layer mixing

from the extensive foot t r a f f i c during instrument placing and in i t i a l soil

1 ayer pl acement . Gravel and sand layers were similarly placed in the weighing lysimeters.

However, the s ize of the weighing lysimeters was a limiting factor, so no

1.9-cm gravel was placed in these. In addition, because the floor of the

weighing lysimeters slopes toward the drain, the pea gravel layer reaches

only one-half the distance across the bottom of the lysimeter (Figure 3.1).

The No. 8 and No. 20-30 sand layers were each placed in 5-cm l i f t s and

leveled as described for the drainage lysimeters. The distance from the top

of the weighing lysimeter t o the geotextile i s about 155 cm.

3.3 PLACEMENT OF FINE SOIL LIFTS

The f ine soil from the McGee Ranch s i t e was placed in the drainage

lysimeters in a ser ies of 5- t o 15-cm l i f t s . By packing the soil in a number

of re1 atively small 1 i f t s , we were bet ter able to control the density of each

l i f t . Before placing any soil in the lysimeters, the depth from the top of

the tank t o the geotextile was measured in four places and averaged. This

value was used as the s tar t ing depth to calculate the f i r s t l i f t height.

Side View

FIGURE 3.1. Layering Sequence of Sands and Gravels in Weighing Lysimeters

The depth from the top of the tank t o the geotextile was approximately

155 cm. This distance of 155 cm from the top of the tank corresponds t o a

soi l depth of 150 cm because the soil surface l i e s approximately 5 cm below

the top of the lysimeters. This configuration of the soi l surface was used

t o minimize losses of f ine so i l s through wind erosion and t o allow us t o

construct an angled buttress of soil around the inner edges of the lysimeter.

This buttress of soi l slopes from the outer edge of the tank t o approximately

7 t o 10 cm from the edge and i s intended to d i rec t water away from the lysim-

e t e r sidewalls, thus preventing preferential flow down the s ide wall of the

lysimeter.

The soi l was loaded in the Bobcat loader and weighed on the platform

scale. Using t h i s weight, and assuming a moisture content from previously

analyzed samples, we calculated the volume which that amount of soi l should

occupy t o achieve a par t icular density a t that moisture content. A wet den-

s i t y value of 1.5 g/cm3 was used t o calculate the f i r s t four 1 i f t s placed in

each lysimeter. Note tha t the wet density i s equal to the dry density plus

the volumetric water content. For example, soil with a density of 1.5 g/cm3

and a water content of 0.10 cm3/cm3 would have a dry (bulk) density of

1.4 g/cm3. The dens i t y o f 1.5 g/cm3 was used f o r t h e bottom l i f t s because

ana lys is o f dens i t y samples taken a t t h e McGee Ranch s i t e showed h igher den-

s i t y values a t depths g rea te r than 1.2 m. A wet dens i t y o f 1.3 g/cm3 was

used t o c a l c u l a t e t h e volume o f t h e remaining l i f t s . Samples were taken from

each bucket l oad o f s o i l and re tu rned t o the l abo ra to ry f o r determinat ion o f

t h e ac tua l moisture content. The s o i l was dropped i n t o the lys imeter ,

spread, and packed by f o o t as c l o s e l y as poss ib le t o the ca l cu la ted 1 i f t

he igh t requ i red t o achieve a p a r t i c u l a r dens i ty .

A f t e r each l i f t was packed and leveled, d is tances from t h e top o f t h e

tank t o two p o i n t s on the s o i l sur face were measured t o determine the ac tua l

l i f t he igh t achieved. I f the ac tua l l i f t he igh t d i d n o t agree we l l w i t h t h e

ca l cu la ted l i f t he igh t , f u r t h e r packing was attempted t o achieve t h e des i red

dens i ty . The f i r s t f o u r l i f t s i n each l ys ime te r consis ted o f on ly one bucket

load o f s o i l , which we attempted t o pack t o a wet dens i t y o f 1.5 g/cm3. This

amount o f s o i l formed a 1 i f t approximately 5 cm i n he igh t .

With the except ion o f t he f i r s t l i f t i n each tank, t he sur face dens i ty /

moisture probe was used t o take a dens i t y and moisture reading on each l i f t

i n two p o s i t i o n s - - n o r t h and south o f t h e neutron and gamma probe access

pipes. At every second l i f t , s o i l densi ty /moisture samples were taken a t t he

p o i n t where t h e probe res ted on t h e s o i l surface. These samples were taken

by pressing a brass c y l i n d e r (approximately 6 cm d i a by 7 cm long) i n t o the

s o i l , removing the s o i l - f i l l e d c y l i n d e r , and ex t rud ing the s o i l sample from

the c y l i nde r i n t o p l a s t i c bags. These samples were used t o generate ca l i b r a -

t i o n curves f o r t he moisture and d e n s i t y probes. This procedure was fo l lowed

u n t i l t he f i n a l l i f t was packed and l eve led 5 cm from the t o p o f t he tank.

An angled l i p o f s o i l was then packed around the edge o f t he drainage l ys im-

e t e r t o prevent p r e f e r e n t i a l f l o w down the s ides o f t he drainage lys imeter .

This c o n f i g u r a t i o n i s shown a t t h e t o p o f F igure 2.6.

The weighing l ys ime te rs were f i l l e d by f o l l o w i n g a s i m i l a r procedure.

The major d i f f e r e n c e i n f i l l i n g t h e weighing l ys ime te rs was t h a t i n a d d i t i o n

t o weighing each load o f s o i l before p l a c i n g i t i n the lys imeter , we a lso

recorded t h e weights o f s o i l shown by the scales beneath the weighing lys im-

e ters . These weights d i d n o t agree as w e l l as we expected. Some o f t he

d i s p a r i t y was a t t r i b u t e d t o rubbing o f t he l ys ime te rs on t h e ou te r t ank w a l l s

o r wedging o f s o i l s o r g rave l a longside t h e scales. When t h e l ys ime te rs were

moved s l i g h t l y on t h e scales by us ing a bar t o s h i f t t h e i r p o s i t i o n , t h e

weights recorded f o r t h e Bobcat on t h e p l a t f o r m scale and t h e weighing lys im-

e t e r scale were i n much b e t t e r agreement. A f t e r complet ing t h e f i n a l f i l l i n g

operat ion, our i n i t i a l check o f t h e sca le weights found them t o be reproduc-

i b l e t o + 0.5 kg f o r a t o t a l weight change o f 220 kg (nonaveraged readings) .

The opera t iona l goal i s f0.050 kg when averaged f o r 1 hour.

The sur face dens i ty probe was used t o reco rd t h e d e n s i t y and

moisture o f each l ift, except f o r t h e f i r s t 5-cm l i f t , which was t o o shal low

t o ob ta in readings. S o i l moisture samples were taken f rom each bucket l o a d

o f s o i l , and mois ture and dens i t y samples were taken f o r every o the r l i f t

from the area where t h e probe res ted on t h e s o i l surface.

Another d i f f e r e n c e between t h e weighing and drainage l ys ime te rs i s t h a t

t he weighing l ys ime te rs have a 10-cm-high ~ l e x i ~ l a s ( ~ ) l i p b o l t e d t o t h e

ou ts ide o f t he l y s i m e t e r wa l l a t t h e top. The top o f t h i s l i p i s even w i t h

t h e ground l e v e l . The p l a s t i c reduces t h e amount o f thermal l oad ing t o t h e

s o i l surface. At t he p o i n t below the s o i l sur face where t h e two m a t e r i a l s

are b o l t e d together , t h e j o i n t a l so forms a b a r r i e r t o p r e f e r e n t i a l f l o w t h a t

might occur down t h e s ides o f t he l y s i m e t e r wa l l s . The s o i l sur face i n t h e

weighing l ys ime te rs i s conf igured i n t he same manner as t h a t i n t h e drainage

lys imeters . An angled bu t t ress o f s o i l , 5 cm i n height , was formed a t t h e

l ys ime te r wa l l t o prevent p r e f e r e n t i a l drainage (see F igure 2.6).

3.4 INSTRUMENTATION AND MEASUREMENT TECHNIOUES

Accurate measurements o f drainage and o ther water-balance parameters are

c r i t i c a l t o t h e success o f the FLTF i n determin ing the e f fec t i veness o f bar-

r i e r s . A l i s t o f measurements and t h e i r expected accuracy was prepared and

(a) Seaman Nucl ear Company, Oak Creek, Wisconsin. (b) P lex ig las i s a t r a d e name o f Rohn and Haas, Co., Ph i l ade lph ia ,

Pennsyl vani a.

included in the experimental plan (Kirkham and Gee 1987). Over the next several years, measurements will be obtained and calibration data collected, which will allow us to refine these estimates.

A1 1 of the lysimeters are instrumented with access wells for neutron and gamma probe measurements, tensiometers, and an array of copper constantan thermocouples appropriate for that treatment. In addition, particular treatments are equipped with arrays of thermocouple psychrometers at different depths. The positions of these sensors in each lysimeter are outlined in the detailed description of each lysimeter and locations and placement are shown in Figure 2.6.

3.5 NEUTRON/GAMMA PROBE AND ACCESS WELLS

Near the center of each lysimeter, three access ports are situated in a triangular configuration. These access wells are 5.08-cm I.D. aluminum pipe with a compression fitting (TP5-2 test plug) in the bottom. During the backfilling, the pipes were held in place 30 cm apart by using a jig. The access wells extend through the sand and gravel layers and the bottom of the pipe rests in the 0.04- to 0.05-m-dia railroad ballast. These access wells are used with both a neutron probe to measure volumetric water content of soils as we1 1 as a gamma probe to measure density.

A surface neutron/gamma probe (Seaman Nuclear, SN-A340)(a) was used to estimate moisture content and density during construction. Calibration data for this probe are presented in Appendix A.

3.6 TENSIOMETERS

Tensiometers measure soil water tension or suction directly by measuring the pressure in the soil water (Hillel 1982). The measurements are typically reported in either cm water or mbars pressure. This measurement is achieved by connecting a water-filled, porous ceramic material, which is in direct contact with the soil material, to a pressure gauge or transducer. As long as water bonds to water or tensiometer material does not break, the soil

(a) Seaman Nuclear Company, Oak Creek, Wisconsin.

3.9

water matric potential (the negative of suction or tension) can be measured. Tensiometers, however, generally fai 1 at soi 1 water tensions greater than about 700 cm water. Tensiometers of this type--a porous ceramic cup connected to a rubber septum via a 2.2-cm-dia PVC pipe--were purchased from Soil Measurement Systems, Las Cruces, New Mexico. The tensiometer unit is filled with water, after it has been determined that the moisture content has increased to above 18 vol% in the surrounding soil. Below that level, the tensions are too high to permit operation of the tensiometers (i.e., the laboratory analysis suggests that tensions at lower water contents exceed 700 cm water). When the soil is wet enough, as indicated by neutron probe readings or direct sampling, the tensiometer is filled and the water columns stoppered with the rubber septum.

Each lysimeter contains three tensiometers: one at 150 cm below the soil surface, one at 100 cm below the soil surface, and one at 50 cm below the soil surface. The porous ceramic cup of each tensiometer was placed 45 cm from the tank wall. The tensiometers were installed through 2.54-cm-dia holes drilled through the tank walls at 152.5 cm, 102.5 cm, and 20 cm from the top of the tank. These holes in the lysimeter walls were sealed with si 1 asti c around the tensiometer to prevent 1 eakage. The two 1 owermost tensiometers were installed at a slight angle upward from the ceramic tip to prevent air entrapment in the PVC tubing linking the porous ceramic cup to the septum end of the tensiometer. These two tensiometers pass through the lysimeter wall into the underground facility.

The tensiometers at the 50-cm depth inside the lysimeters extend upward and out through the lysimeter walls at a point 20 cm below the soil surface. From this point they are surrounded, insulated, and protected by 3-in. PVC pipes that extend to the soil surface.

3.7 THERMOCOUPLES

Thermocouples (copper/constantan) were installed in each lysimeter to monitor vertical and horizontal temperature gradients in selected lysimeters. Thermocouples are monitored continuously with a CR7 (Campbell Scientific Inc., Logan, Utah) data1 ogger, with sel ected measurements output hourly and

sl ower changi ng measurements output dai 1 y . Thermocoupl es were checked during installation to ensure that temperatures measured were correct. The particu- 1 ar array and arrangement of thermocouples instal led in each lysimeter is detailed in the individual discussion of each lysimeter.

Thermocouples were installed in the lysimeters by feeding the wires through 1.27-cm holes drilled through the tank walls. When installing the thermocouples at the 150-cm soil depth, a 1-cm layer of soil was placed between the thermocouple and the geotextile. For the vertical arrays, the thermocouple junction was placed in each lysimeter at a distance 30 cm from the tank sidewall. Horizontal arrays were placed in as straight a line as possible across the lysimeter at the appropriate depth. Horizontal arrays that were placed i'n the basalt 1 ayer were encased in on(^) tubing to prevent the riprap 'material from abrading the wires. The thermocouple junctions were fed through slits in the tubing and projected out 5 cm per- pendicular to the Tygon support tube to ensure an accurate reading. Care was also taken to place the tubing far enough away from the probe ports to ensure that neutron probe readings would not be affected by the hydrogen in the plastic tubing.

In addition, two chromel-constantan thermocouples encased in stainless steel were placed in the soils surrounding the lysimeter facility. Readings from these thermocouples may be used to compare soil temperatures outside the facility with temperatures inside the lysimeters.

THERMOCOUPLE PSYCHROMETER

The thermocouple psychrometer (TCP) measures total water potential (including matric and osmotic). A brief description of the operation of a thermocouple psychrometer is given in Hillel (1982) and detail related to operational use is provided by Rawlins and Campbell (1986). It is suitable for measurements of total water potentials less (more negative) than -0.1 MPa (-1 bar). This device consists of two thermocouple junctions of different mass made from chromel-constantan thermocouple wire placed inside a wire

- -

(a) Tygon is a registered trade name of the U.S. Stoneware Co., Akron, Ohio.

3.11

( s t a i n l e s s s t e e l ) screen cage. The dimensions o f t he cage a re approximately

0.5 cm i n d i a by 1.0 cm i n length . The device i s p laced i n s o i l t o a des i red

depth, and s o i l i s packed around t h e TCP u n i t so t h a t s o i l water vapor equ i -

l i b r a t e s w i t h t h e water vapor (humid i ty ) i n t h e screen cage. The TCP i s

designed so t h a t t h e small j u n c t i o n i s cooled f o r a s h o r t p e r i o d o f t ime,

which causes condensation o f water vapor on it. Fo l lowing cool ing, a measur-

able vo l tage i s generated as t h e condensed water evaporates and coo ls t h e

thermocouple j u n c t i o n o f smal le r mass. The vo l tage i s a f u n c t i o n o f t h e

evaporat ion r a t e (wet-bulb depression), which i s , i n t u rn , a f u n c t i o n o f t h e

vapor pressure i n e q u i l i b r i u m w i t h surrounding s o i l . The c a l i b r a t i o n o f t h e

TCP i s obta ined when t e s t s o f wet-bulb depressions over known s a l t s o l u t i o n s

w i t h s p e c i f i e d water p o t e n t i a l s produce vo l tage versus water p o t e n t i a l

curves. Factory c a l i b r a t i o n values are presented i n Table A.3, Appendix A,

f o r most o f t h e TCPs used i n the l ys ime te rs .

Because p l a n t water uptake i n t h e vegetated l ys ime te rs i s expected t o

d r y t h e s o i l below t h e range where tensiometers w i l l work ( i .e . , below a

m a t r i c p o t e n t i a l o f -0.07 MPa), t h e TCP u n i t s w i l l be used. They work i n t h e

range from -0.1 t o -8.0 MPa. For t h e f i n e s o i l used i n t h e lys imeters , t h i s

range a l lows measurement o f water contents ranging from about 4 w t % t o above

10 wt%.

Arrays o f TCPs were i n s t a l l e d a t f o u r depths i n t h e weighing l ys ime te rs

t h a t ho ld vegetated treatments: t h r e e a t 150 cm from t h e s o i l surface, t h ree

a t 100 cm from t h e s o i l surface, t h r e e a t 50 cm from t h e s o i l surface, and

th ree a t 30 cm from the s o i l sur face. Arrays o f TCPs were i n s t a l l e d a t t h r e e

depths i n t h e weighing l ys ime te rs t h a t have bare sur face treatments: t h r e e

a t 150 cm, t h r e e a t 100 cm, th ree a t 50 cm. The a d d i t i o n a l a r ray i n t h e

vegetated t reatments i s intended t o mon i to r t h e s o i l water p o t e n t i a l o f t h e

r o o t zone o f t h e common perennia l grasses t h a t are p a r t o f t h e vege ta t i ve

cover on t h e l ys ime te rs . The TCPs are monitored on a CR7 data logger and the

TCP program i s l i s t e d i n Appendix A.

3.9 ROOT OBSERVATION TUBES/RHIZOTRONS

Root observat ion tubes were i n s t a l l e d i n those l ys ime te rs conta in ing

vegetated treatments. The tubes are constructed o f c l e a r glass, 5.4 cm i n

d ia , and 'are marked and numbered a t 5-cm depth i n t e r v a l s . The bottoms o f t h e

tubes are sealed. These p o r t s w i l l be used w i t h a small down-hole video

camera t o observe r o o t development and a c t i v i t y through time.

4.0 DETAILED LYSIMETER DESCRIPTIONS

The following section characterizes each lysimeter as it was filled

during May or June 1987, including the results of 1 aboratory analyses performed for the soils in that lysimeter, results of field measurements taken while filling the lysimeter, and an out1 ine of the placement of sensors in the lysimeter. A1 1 18 lysimeters are equipped with three neutron/gamma probe access wells in a triangular configuration.

Table A.4 in Appendix A gives the density and moisture measurements for

all samples for all drainage lysimeters. Soil samples were analyzed for particle size, saturated hydraulic conductivity, and water retention. Results from completed analyses are presented in Section 6.0 and in Appendix A.

Legends for all lysimeter moisture profiles contain the following 1 abels:

GRAV CAN = the gravimetric moisture content determined for the small core sample

GRAV BAG = a composite grab sample taken before compacting the soil in each

VOL CAN = GRAV CAN * bulk density for that sample

VOL NP = volumetric moisture data taken with surface neutron moisture probe.

Each label is repeated twice as two samples were taken generally from the north or south side of the lysimeter in the case of the CAN and NP data, and one BAG from each bobcat bucket load of soil (usually two bucket loads per lift).

The legend for all of the following lysimeter density profiles contains the following labels: WET-CAN = the wet soil density in the core, SEAMAN =

density value determined using surface moistureldensity probe, SCALE = soil density estimated from weights of bobcat loads of soil, DRY-CAN = correction

of the WET-CAN data to dry soil density. As previously described, the

legends are repeated for two samples for each 1 ift.

4.1 DRAINAGE LYSIMETER 1 (D01-2)

D01-2 is a replicate of Treatment 2: 1.5 m of fine soil, ambient precipitation, and bare surface. This lysimeter contains three tensiometers installed at depths 150 cm, 100 cm, and 50 cm below the soil surface and thermocouples installed at the same depths. Figures 4.1 and 4.2 show the density and moisture profile of the backfill in this lysimeter.


D02-5 is a replicate of Treatment 5: 1.5 m of fine soil with surface gravel admix in the top 20 cm, ambient precipitation, and vegetation. Three tensiometers are installed in this lysimeter at 150 cm, 100 cm, and 50 cm below the soil surface. In addition to vertical thermocouples at 50, 100, and 150 cm, this lysimeter contains two horizontal arrays of thermocouples at 100 cm and 250 cm below the soil surface. The horizontal arrays are composed of a string of thermocouples placed the following distances from the tank wall: 0 (inner tank wall), 5, 10, 50, 100, 150, 190, 195, and 200 cm (outer tank wall). This lysimeter will be vegetated, so it contains a root- observation tube. Figures 4.3 and 4.4 show the density and moisture profiles of the fine soils in this lysimeter.


D03-6 is a replicate of Treatment 6: 1 m o f fine soil layer ambient precipitation, and vegetation. Three tensiometers are installed in the lysimeter at 150, 100, and 50 cm below the soil surface, and thermocouples are installed at the same depths. This lysimeter also has a horizontal array at 100 and 250 cm below the soil surface. The horizontal arrays are composed of a string of thermocouples placed the following distances from the tank wall: 0 (inner tank wall), 5, 10, 50, 100, 150, 190, 195, and 200 cm (outer tank wall). Because this is a vegetated treatment, this lysimeter contains a root observation tube. Figures 4.5 and 4.6 show the density and moisture profiles of the fine soils in this lysimeter.

,-63- Grav Can L-Z- Grav Can ....... .k.. .... Grav Bag - -v- - Grav Bag -.-+.- Vol Can -..-. -..-- Vol Can + Vol NP -A- Vol NP

H,O (g/g and cm3/cm3)

FIGURE 4.1. Moisture Profile for Lysimeter D01-2

0

-- -50 E 0 V

5 P a " -100

-1 50

1 .O 1.2 1.4 1.6 1.8 2.0 Density (g/cm3)

U Wet-Can ---0- Wet-Can ....... .&. ..... Seaman - -v- - Seaman -.-+--- Scale -.--. 0 -..-. Dry-Can

4 Dry-Can

FIGURE 4.2. Density Profile for Lysimeter D01-2

, - = I Grav Can Grav Can

- - - - . . . .A - - - .- - - Grav Bag - -v- - Grav Bag ---+-.- Vol Can --.-- ----. Vol Can d Vol NP -A- Vol NP



W Wet-Can Wet-Can

. .. . . - . .A,. . . . . . . Seaman - -v- - Seaman - . - -0 - . - Scale ----- I7 --.-- Dry-Can

U Dry-Can

Density (g/cm3)

FIGURE 4 . 4 . Density P r o f i l e for Lysimeter D02-5

Grav Can -c- Grav Can - . - . -. . .A.. . . .. - - Grav Bag

- -V- - Grav Bag ----0--- Vol Can -..-- .; -..-- Val Can ,+ VOI NP A - VOI NP


FIGURE 4 .5 . Moisture Profile for Lysimeter D03-6

---I3--- Wet-Can Wet-Can

. .. - ..-.A - - . .--- Seaman - -v- - Seaman ---e--- Scale --.-- -.--- Dry-Can ---O--- Dry-Can

-1 50

1 .O 1.2 1.4 1.6 1.8 2.0 Density (g/cm3)


4.4 DRAINAGE LYSIMETER 4 (D04-11

D04-1 i s a r e p l i c a t e o f t h e op t im i zed b a r r i e r system, Treatment 1:

1.5 m o f f i n e s o i l , ambient p r e c i p i t a t i o n , and vegetated. Again, t h r e e t e n -

s i o m e t e r ~ a r e i n s t a l l e d a t 150, 100, and 50 cm below t h e s o i l su r face . I n

a d d i t i o n t o h o r i z o n t a l a r rays o f thermocouples a t 100 and 250 cm--placed a t 0

( i n n e r t ank w a l l ) , 5, 10, 50, 100, 150, 190, 195, and 200 cm ( o u t e r t a n k

w a l l ) - - t h i s r e p l i c a t e con ta ins a more complete v e r t i c a l a r r a y o f thermo-

couples. The v e r t i c a l a r rays c o n s i s t o f thermocouples p laced 30 cm f rom t h e

i n n e r t ank w a l l a t t h e f o l l o w i n g depths below t h e s o i l su r face : 5, 10, 20,

30, 40, 50, 100, and 150 cm. D04-1 a l s o con ta ins a g l a s s tube f o r r o o t

observa t ion . F i gu res 4.7 and 4.8 show t h e d e n s i t y and mo i s tu re p r o f i l e s .


D05-5 i s a r e p l i c a t e o f Treatment 5: 1.5 m o f f i n e s o i l w i t h g rave l

admix i n t h e t o p 20 cm, ambient p r e c i p i t a t i o n , and vege ta t i on . Tensiometers

were i n s t a l l e d a t 150, 100, and 50 cm below t h e s o i l su r f ace as were thermo-

couples. The t r ea tmen t i nc l udes a r o o t obse rva t i on tube. F i gu res 4.9 and

4.10 show t h e d e n s i t y and mo i s tu re i n f o r m a t i o n f o r t h e s o i l s p laced i n t h i s

l y s i m e t e r .


D06-6 i s t h e second r e p l i c a t e o f Treatment 6: 1 m o f f i n e s o i l , ambient

p r e c i p i t a t i o n , and vege ta t ion . Again, tens iometers and thermocouples were

i n s t a l l e d a t 150, 100, and 50 cm below t h e s o i l su r face , and a r o o t obser-

v a t i o n tube was i n s t a l l e d . F igures 4.11 and 4.12 show t h e mo i s tu re and

d e n s i t y p r o f i 1 es f o r t h e b a c k f i l l ed s o i l .


D07- 1 i s t h e second rep1 i c a t e o f Treatment 1 : 1.5 m o f f i n e s o i l , ambient p r e c i p i t a t i o n , and vege ta t i on . T h i s l y s i m e t e r d i d n o t r e c e i v e t h e

h o r i z o n t a l and v e r t i c a l a r rays o f thermocouples i n s t a l l e d i n 004-1. Tensio-

meters and thermocouples were i n s t a l l e d a t t h e same t h r e e depths: 150, 100,

and 50 cm below t h e s o i l su r face . Because t h i s i s a vegetated t reatment ,

0

-50 E 0 V

5 CZ a

-100

-1 50

0.10 0.15 0.20 0.25


FIGURE 4.7. Moisture Profile for Lysimeter

0

-- -50 E 0 Y

5 a Q)

-100

-1 50

1 .O 1.2 1.4 1.6 1.8 2.0

Density (gIcm3)

Grav Can Grav Can Grav Bag Grav Bag Vol Can Vol Can Vol NP Vol NP

,-!- Wet-Can k-Z- Wet-Can - -. . * - - .A - - - - .. - Seaman - -v- - Seaman ---+-.- Scale --.-. --.-. Dry-Can

+ Dry-Can

FIGURE 4.8. Density Profile for Lysimeter 004-1

U Grav Can ---O--- Grav Can - - - . . . -.A. .. - - -- - Grav Bag - - v- - Grav Bag - . - -0 - . - Vol Can -..-- ----- Vol Can d Vol NP -A- Vol NP

H,O (gig and cm3/cm3)


.-El-, Wet-Can U Wet-Can - .. . - - - .A. - - - .. - . Seaman - -v- - Seaman - - - -0 - . - Scale ----- 0 -.--- Dry-Can

Dry-Can

Density (g/cm3)


0

-I- Grav Can

- -50 i-2- G rav Can E - .. . . .. .a.. .- . . -. 0 Y

Grav Bag - -v- -

5 Grav Bag P. -.-+--- Q) Vol Can -100

-..-. ----- Vol Can -+, VOI NP -A- VOI NP

-1 50

0.10 0.15 0.20 0.25

H,O (glg and crn3/cm3)


,-I-- Wet-Can -C- Wet-Can - .-. - - - .A. . .- . . . - Seaman - -v- - Seaman ---+--- Scale ----. 0 -.--- Dry-Can

+ Dry-Can

1 .O 1.2 1.4 1.6 1.8 2.0 Density (g/cm3)


root observation tubes were instal led to a1 low us to document root growth and

activity. Figures 4.13 and 4.14 show moisture and density information.


D08-2 is the second replicate of Treatment 2: 1.5 m of fine soil, ambient precipitation, and bare surface. Tensi ometers and thermocouples were installed at 150, 100, and 50 cm from the soil surface. Figures 4.15 and

4.16 show the moisture and density profiles for the lysimeter.


D09-7 is a replicate of Treatment 7: 1.5 m of fine soil, bare soil sur-

face, and precipitation until breakthrough. Note that the layering in D09-7

is slightly different than the rest of the drainage lysimeters. (See Sec- tion 3.0 on placement of basalt, gravel, and sand layers.) This lysimeter

contains three tensiometers installed at depths of 150, 100, and 50 cm below the soil surface. Thermocouples are installed at the same depths. Fig- ures 4.17 and 4.18 show the moisture and density profiles for the lysimeter.


D10-4 is a replicate of Treatment 4: 1.5 m of fine soil, twice average

precipitation, and bare soil surface. In addition to tensiometers and thermocouples at 150, 100, and 50 cm below the soil surface, this treatment has a horizontal array of thermocouples at 50 and 250 cm below the soil surface consisting of thermocouples at 0 (inner tank wall), 5, 10, 50, 100, 150, 190, 195, and 200 cm (outer tank wall). The moisture and density profiles for this lysimeter are shown in Figures 4.19 and 4.20.

4.11 DRAINAGE LYSIMETER 11 (Dll-7)

Dll-7 is the second replicate of Treatment 7: 1.5 m of fine soil, bare soil surface; and precipitation until breakthrough. This lysimeter is also

instrumented with tensiometers and thermocouples at 150, 100, and 50 cm below

the soil surface. Moisture and density profiles are shown in Figures 4.21

and 4.22.

0

-50 E 0 w

5 9. a -100

-1 50

0.10 0.15 0.20 0.25

H,O (glg and cm3/cm3)

FIGURE 4 .13 . Moisture Profile for Lysimeter

Grav Can Grav Can Grav Bag Grav Bag Vol Can Vol Can Vol NP Vol NP

Wet-Can Wet-Can Seaman Seaman Scale Dry-Can Dry- Can

FIGURE 4 . 1 4 . Density Profile for Lysimeter DO7

-I- Grav Can

- ---O--- Grav Can . . -. . . . .A*. . . . . . - Grav Bag - -v- - Grav Bag

---so--- Vol Can - --.-- --.-- Vol Can

,- VOI NP -A- VOI NP



Density (g/cm3)

FIGURE 4.16. Density Profile for Lysimeter D08-

Wet-Can Wet-Can Seaman Seaman Scale Dry-Can Dry- Can

,-Z-, Grav Can -2- Grav Can . . -. . . ..A . . . .. . . Grav Bag - -v- - Grav Bag -.-e-.- Vol Can ----. w -..-. Vol Can

,+, VOI N P -A- VOI N P

I I

I I I

0.10 0.15 0.20 0.25



,-I- Wet-Can ---O--- Wet-Can - . . . . - . .A. - - . . - . Seaman - -v- - Seaman - . - -0 - . - Scale -----a ----. Dry-Can

U Dry-Can

Density (g/cm3)


U Grav Can + Grav Can - ........A.. -. .-. - Grav Bag - -v- - Grav Bag -.-*--- Vol Can

- -.--. -..-- Vol Can d Vol NP -A- Vol NP



-I- Wet-Can -C- Wet-Can -. . . - - - .A- . - - - - - Seaman - - V- - Seaman ---*--- Scale ----- u ----- Dry-Can

,-C- Dry-Can


0

-- -50 E 0 Y

5 P Q,

-1 00

-1 50

0.10 0.15 0.20 0.25


--I-- Grav Can ,-C- Grav Can - -- .-. . .A.. - .. - . - Grav Bag - -v- - Grav Bag ---+--- Vol Can -.--- # -..-. Vol Can .+- VOI NP -A- Vol NP

I I I

I I I

I I I

1 .O 1.2 1.4 1.6 1.8 2.0 Density (g/cm3)

FIGURE 4.21. Moisture Profile for Lysimeter 011-7

-El- Wet-Can Wet-Can

. *. - . . ..A . . . *. -. Seaman - -v- - Seaman ---+--- Scale -..-. C) --.-. Dry-Can + Dry-Can

FIGURE 4.22. Density Profile for Lysimeter Dll-7


D12-4 is the second replicate of Treatment 4: 1.5 m of fine soil, bare

soil surface, and twice average precipitation. This lysimeter contains ther-

mocouples and tensiometers at 150, 100, and 50 cm below the soil surface. Figures 4.23 and 4.24 show the density and moisture profiles for this

treatment.


D13-3 is a replicate of Treatment 3: 1.5 m of fine soil, twice average

precipitation, and vegetated. Tensiometers and thermocouples were installed

at 150, 100, and 50 cm below the soil surface. This treatment also includes a root observation tube to document root growth and activity. Figures 4.25

and 4.26 show the density and moisture profiles.


D14-3 is the second replicate of Treatment 3: 1.5 m of fine soil, twice average precipitation, and vegetated. It contains exactly the same sensors

as D13-3: tensiometers and thermocouples at 150, 100, and 50 cm below the

soil surface; and a root observation tube. Graphs of the moisture and density information are given in Figures 4.27 and 4.28.

4.15 WEIGHING LYSIMETER 1 (W01-1)

W01-1 is the third replicate for Treatment 1, the optimized barrier system: 1.5 m of fine soil, ambient precipitation, and vegetation. As discussed in Section 3.0, the weighing lysimeters were equipped with TCPs. Because this lysimeter will hold a vegetated treatment, three TCPs were

placed at each of four depths in the lysimeter--a total of 12 TCPs in this

treatment. From an observer's position inside the facility facing the inside

wall of the lysimeter about 30 cm from one edge, all four strings of TCPs point directly away from the observer in horizontal lines at depths of 150,

100, 50, and 30 cm. The wires were passed through a 1.27-cm-dia hole drilled in the lysimeter sidewall that faces into the underground facility.



--I)--- Grav Can ---O--- Grav Can - - . ..--.A -. -. - - - Grav Bag - -v- - Grav Bag - - - .o-.- Vol Can ----- -..-- Vol Can A Vol NP -A- Vol NP

1 .O 1.2 1.4 1.6 1.8 2.0 Density (g/cm3)

,-El- Wet-Can ~-2- Wet-Can - -. - . .-.A. - - . - - -. Seaman - -v- - Seaman -.-+-.- Scale ----- ----. Dry-Can

U Dry-Can


0.10 0.1 5 0.20 0.25


U Grav Can Grav Can

. . . - . . . .A,. . - . -- - Grav Bag - -v- - Grav Bag ---+.- Vol Can -.--. -..-. Vol Can

+ Vol NP -A- Vol NP


1 .O 1.2 1.4 1.6 1.8 2.0 Density (g/cm3)

-3, Wet-Can + Wet-Can - - ----..A. -. - - -. - Seaman - -v- - Seaman - . - -0 - . - Scale ----. 17 ----- Dry-Can U Dry-Can


-1 50

0.10 0.15 0.20 0.25


FIGURE 4 . 2 7 . Moisture Profile for Lysimeter D14-3

Density (g/cm3)

--3 Grav Can ---O--- Grav Can ....... .A.. ...... Grav Bag - -0- - Grav Bag

---9--- Vol Can -..-- -..-. Vol Can +, VOI NP -A- Vol NP

-E- Wet-Can + Wet-Can --......A ....... Seaman - - V- - Seaman - . - -0 - - - Scale -..-. 0 --.-- Dry-Can U Dry-Can

FIGURE 4.28. Density Prof i 1 e for Lysimeter D14-3

The lysimeter sidewalls that face into the underground portion of the facil-

ity are accessible through doors that open into each outer box.

The weighing lysimeters all contain vertical and horizontal arrays of

thermocouples. As in the drainage lysimeters, the vertical arrays consist of

thermocouples placed 30 cm from the tank wall at the following depths from

the soil surface: 5, 10, 20, 30, 40, 50, 100, and 150 cm. The horizontal

arrays consist of thermocouples placed 100 cm from the soil surface at 0, 5,

10, 50, 100, 150, 190, 195, and 200 cm from the inner tank wall. Weighing

lysimeter 1 had tensiometers installed horizontally at 150 and 100 cm below

the soil surface. A tensiometer was installed vertically at the 50-cm depth. The two tensiometers, instal 1 ed horizontal ly, penetrate the lysimeter sidewall but not the outer box. The porous ceramic ends of the tensiometers lie

45 cm from the inner lysimeter wall. Access to these instruments for filling

the tensiometers and recording measurements is through the doors opening into

the underground facility. A root observation tube was also installed in this treatment. Moisture and density profiles for this lysimeter are given in

Figures 4.29 and 4.30.


This lysimeter represents the third replicate of Treatment 2: 1.5 m of

fine soil, ambient precipitation, and a bare surface. Tensiometers were

installed at depths of 150 and 100 cm from the soil surface as described for W01-1. Again, the tensiometer at the 50-cm depth was installed in a vertical

position. Arrays of three TCPs were placed as described above for W01-1 at

depths of 150, 100, and 50 cm from the soil surface. Because this treatment does not include vegetation, an array of TCPs at 30-cm depth was not installed. Weighing lysirneter 2 contains vertical and horizontal thermo-

couple arrays identical to those in W01-1. Moisture and density profiles for

this lysimeter are given in Figures 4.31 and 4.32.


W03-3 contains the third replicate of Treatment 3: 1.5 m of fine soil,

vegetation, and twice average precipitation. This lysimeter contains exactly

-1 50 1.3 1.4 1.5 1.6 1.7

Density (gig and cm3/cm3)


FIGURE 4.29 . Moisture Profile for Lysimeter W01-1

FIGURE 4.30. Density Profile for Lysimeter W01-1

- ,-C-, N-Grav ,- N-VOI -...... 13 --.-.-- S-G rav - -.- - - S-Vol

0.10 0.i 5 0.20 0.25


FIGURE 4.31. Moi sture Prof i 1 e for Lysimeter W02-2



the same instruments as W01-1 in the same configuration. Moisture and density profiles for this lysimeter are shown in Figures 4.33 and 4.34.

4 .18 WEIGHING LYSIMETER 4 (W04-41

W04-4 is the third rep1 icate of Treatment 4: 1 .5 m of fine soil, twice average precipitation, and bare surface. This lysimeter contains exactly the same instrumentation as W02-2 described previously. Moisture and density profiles for this lysimeter are shown in Figures 4.35 and 4.36.


FIGURE 4.33. Moisture Profile for Lysimeter W03-3

1.3 1.4 1.5 1.6 1.7


FIGURE 4.34. Density P r o f i l e f o r Lysirneter W03-3

.-C-, N-Grav - N-VOI

....-.. j -~ -.....- S-G rav - -.- - S-Vol

0.10 0.1 5 0.20 0.25


FIGURE 4.35. Moisture P r o f i l e f o r Lysirneter W04-4

Density (glg and cm3/cm3)


5.0 RAINFALL SIMULATOR

A rainfall simulator, or rainulator, was constructed to apply water uniformly to the soil surface of each of the eight lysimeters that receive more than ambient precipitation. The rainulator is mounted on a carriage assembly, which is driven by an electric motor through a reduction gear. This carriage assembly moves equipment and personnel above the lysimeter facility without contacting the soil surface. Wheels on the carriage assembly run along steel tracks along each edge of the lysimeter facility. The personnel and instrument carrier is mounted to the carriage assembly and can be pro- pelled along the length of the carriage by hand. (A diagram of the rainfall simulator and carriage assembly is shown in Figure 5.1.)

A spray bar attached to the carriage delivers water uniformly to those lysimeters on the west side of the facility that are designed to receive irrigation treatments. The spray bar has six nozzles that disperse the water in a long, narrow elliptic pattern on the soil surface, with a 50% overlap. Water is provided through a hose that is pulled along the ground by the carriage and connected to the pressure-regulated spray bar.

The rainul ator was used to apply Columbia River water to treatments 3, 4, and 7, as shown in Table 5.1. The amount of water and the uniformity of its application were measured by placing small, cylindrical rain gauges in four locations along the water application traverse. Water is added until the total amount equals twice the average for the period. Water applied to D09-7 and Dll-7 was limited to 2 cm per application to avoid ponding and channeling. A 2-cm application was made each week until breakthrough occurred.

TABLE 5.1. Water Added t o Lysimeters a t the F i e l d Lysimeter Test F a c i l i t y (FLTF) from November 5, 1987, Through June 21, 1988

Date

Water added ( i n cm)

P rec i p i t a t i on

TOTALS

~ 0 9 - 7 ( ~ ) 010-4 011-7 012-4 D13-3 D14-3 W03-3 30946. 4(b) 30542.4 30837.4 31290.4 30977.6 30666.5 23424

Water Added by I r r i q a t i o n (cm/H20)

0 0.6 0 0.6 0.6 0.6 0 0 0 0 0 0 0 0.5 0 1.9 0 1.8 1.9 1.9 2.5 0 2.2 0 2.1 2.1 2.2 1.5 0 1.4 0 1.4 1.4 1.4 1.2 2.0 0.5 2.0 0.5 0.5 0.5 0.5 2.0 0.8 2.0 0.8 0.8 0.8 0.8 2.0 0.8 2.0 0.8 0.8 0.8 0.8 2.0 1 .o 2.0 1 .o 1 .o 1 .o 1 .o 2.0 0.8 2.0 0.8 0.8 0.8 0.8 2.0 1.5 2.0 1.5 1.5 1.5 1.5

(a) Lysimeter i den t i f i c a t i o q number. (b) Area o f lysimeter i n cm .

6.0 HYDRAULIC PROPERTIES

Previous modeling e f f o r t s (Fayer e t a l . 1985; Fayer 1987) have shown

t h a t water storage and hydraulic propert ies of the surface soi l 1 argely con-

t r o l water i n f i l t r a t i o n in to and through the bar r ie r . Previous WHC and PNL

s tudies (Myers 1985; Last e t a1 . 1987) have ident i f ied the McGee Ranch s i t e ,

adjacent t o the Yakima Barricade, as a potential source of surface so i l

material f o r protective bar r ie r t e s t i ng . Materials taken from McGee Ranch

have been used t o f i l l the lysimeters a t the FLTF f o r t e s t i ng of water

i n f i l t r a t i o n and erosion control .

Hydraulic property data were obtained on selected lysimeters t ha t pro-

vide input f o r model simulations of the FLTF bar r ie r configurations. These

data incl ude saturated hydraul i c conductivity, water retention character-

i s t i c s , and selected physical proper t ies , such as bul k density and pa r t i c l e -

s i z e analysis , which are useful in characterizing the va r i ab i l i t y of so i l

materials . This section documents the hydraulic propert ies of surface soi l

materials taken from the McGee Ranch t ha t have been used t o f i l l the FLTF

lysimeters. To date , there have been 16 samples of soi l materials analyzed.

The water storage, water re tent ion, hydraulic conductivity, bulk density, and

pa r t i c l e - s i ze analysis data are reported f o r these so i l materi a1 s .

6.1 MATERIALS

Sixteen samples of soi l material used f o r the FLTF were analyzed. The

s o i l , taken from the McGee Ranch located jus t northwest and across Highway 24

from the Yakima Barricade, i s a surface soi l ( t en ta t ive ly c l a s s i f i ed as

Warden S i l t Loam, a Xeroll i c Camborthid). The soi l was taken from the top

meter of a borrow a t the McGee Ranch (Figure 6.1) and stockpiled near the

FLTF fo r f i l l i n g of the lysimeters. Samples were chosen based on a range of

textures obtained by pa r t i c l e - s i ze analyses from samples taken during the

f i l l i n g operation of the FLTF. The samples were analyzed for hydraulic con-

ductivi t y and water retention charac te r i s t i cs . Table 6.1 indicates the

lysimeters and the l i f t s from which the samples were taken.

FIGURE 6.1. Map o f the McGee Ranch S i t e

I 5- 3

3 a<

% McGee Ranch

Site

Field-Plot Experiment

Ecophysiology Study Plots

Source Area for Transplanted Vegetation

I N

I

Hanford Meteorological Station

I

\

200 East

McGee Soil Barricade I Field Lysimeter Quarry

200 West

Test Facility

-

L i f t Nwber -

1 2 3 4 5 6

QI 7

0 8 9

10 11 12 13 14

15 16 17 18 Note:

TABLE 6.1. S o i l L i f t Depths ( i n cm) f o r t h e Drainage Lysimeters a t F i e l d Lysimeter Test F a c i l i t y (FLTF)

155.0 155.0 105.0 155.0 155.0 105.0 155.0 155.0 155.0 155.0 155.0 155.0 155.0 155.0 150.2 148.5 99.8 149.9 149.8 99.4 149.8 151.5 143.6 150.6 148.9 150.4 149.3 149.9 144.1 142.2 94.5 144.1 143.6 93.2 142.8 147.1 137.4 144.9 142.7 143.8 143.9 144.1 138.6 137.1 88.6 138.3 137.5 86.8 136.2 142.3 131.8 140.0 136.2 137.0 137.1 138.8 132.7 130.5 81.4 130.7 132.0 80.2 130.3 137.5 121.3 135.2 130.8 131.1 131.5 133.0 121.2 120.5 68.3 118.5 122.5 66.3 117.4 126.2 108.1 125.1 117.7 118.0 117.7 ,120.7 109.6 111.0 55.0 105.9 108.8 52.3 103.7 114.6 100.7 111.8 105.2 103.9 104.0 106.7 95.6 101.9 41.8 94.5 95.2 38.6 91.4 104.2 89.3 97.6 92.4 88.1 91.3 92.1 85.3 90.0 29.8 82.9 81.9 24.9 78.9 92.2 76.6 84.4 78.7 74.8 78.5 78.5 73.7 79.4 16.0 69.8 68.9 12.1 65.8 79.5 64.4 70.6 67.4 62.4 66.9 66.7 62.8 68.4 5.0 56.9 57.0 4.9 52.0 67.2 51.9 58.7 54.0 49.8 55.4 53.9 52.7 57.6 0.0 46.2 42.6 0.0 40.4 56.2 37.6 44.6 42.3 36.3 43.7 39.4 42.2 47.5 34.0 29.9 28.5 44.3 25.2 30.9 29.7 24.4 30.9 24.4 31.0 37.5 19.8 16.4 16.6 32.0 10.5 18.4 16.2 11.9 17.5 9.5 19.8 27.5 4.2 4.9 5.1 20.4 0.0 4.5 4.9 5.0 5.0 5.0 8.5 16.5 0.0 0.0 0.0 8.3 0.0 0.0 0.0 0.0 0.0 0.0 5.3 0.0

0.0 Depth measured from bottan of so i l layer t o top of lysimeter l i p . L ip of lysimeter extends about 5 cm above packed s o i l surface. Underlined samples indicate those selected for hydraulic prc,perty measurements.

Resul t s of t e x t u r a l ana lyses of t h e s o i l m a t e r i a l s a r e 1 i s t e d i n

Table 6.2. All c a l c u l a t i o n s were done using an average p a r t i c l e d e n s i t y of 3 2.72 g/cm . Soi l t e x t u r e s were obtained using t h e hydrometer procedure (Gee

and Bauder 1986). The c l a y was d ispersed by son ic a g i t a t i o n r a t h e r than t h e

mechanical mixing descr ibed i n t h e s tandard procedure. Tes t s a r e under way

t o eva lua t e t h e e f f e c t s of sonic v i b r a t i o n f o r p a r t i c l e d i s p e r s i o n on t h e s e

s o i l s and wi l l be repor ted in f u t u r e PNL documents. The s i z e ranges of par -

t i c l e s were: 32 t o 44% f o r sand; 42 t o 59% f o r s i l t ; and 7 t o 16% f o r c l ay -

s i zed m a t e r i a l s . The t e x t u r e s ranged from loam t o s i l t loam.

6.2 METHODS

Methods of measuring hydraul ic conduct iv i ty a r e d iv ided i n t o t h e

fol lowing t h r e e types .

6 .2 .1 Hydraulic Conduct ivi ty: Sa tura ted

Sa tu ra t ed hydraul ic conduct iv i ty on each of the 16 samples was d e t e r -

mined using a f a l l i n g head method (Klute and Dirksen 1986). In t h i s method, 3 each sample was packed in a con ta ine r t o a d e n s i t y of 1.37 g/cm and enclosed

with l i d s having an inf low valve a t one end and an outf low va lve a t t h e o t h e r

end. The inf low va lve was connected t o a s tandpipe of a known c r o s s -

s ec t iona l a rea and he ight . The samples were sa tu ra t ed by slowly wet t ing from

t h e bottom and allowing t o s tand f o r 24 hours before any t e s t runs were done.

Af te r s a t u r a t i o n , an i n i t i a l head i n t h e s tandpipe was recorded and water

TABLE 6.2. Textural Analysis of 16 F ie ld Lysimeter Tes t F a c i l i t y Samples

Sampl e % Sand % S i l t % Cl av Sample % S a n d % S i l t % C l a y

was allowed to flow from the standpipe through the sample for a given length of time. The head level in the standpipe, observed at the end of test, was also recorded. Test runs were repeated five times and the values averaged for the calculations. The hydraul ic conductivity (Ks) was determined using the foll owing equation:

where a = cross-sectional area of the standpipe 1 = length of the sample A = cross-sectional area of the sample t = time for the hydraulic head to decrease from H1 to H2 H1 and HZ are hydraul i c heads at beginning and end of the test, respect i vel y .

6.2.2 Hvdraulic Conductivitv: Unsaturated

Solving an unsaturated flow problem requires evaluation of soil hydraulic properties. These properties include, but are not limited to, 1) the relationship between capill ary head and moisture content and 2) the dependence of the hydraulic conductivity on moisture content. It is often imposs- ible to determine all data necessary for a complete analysis. As an example, soils data from the Hanford Site are available largely through corings and sieve analyses. Virtually no hydraulic properties of the sediments have been measured directly. Thus, to predict water flow in these sediments, empirical relationships need to be established between known physical properties and hydraulic characteristics, then an estimation of water flow in the vadose zone at the Hanford Site can be made.

Details of the methods (and models) for predicting the unsaturated conductivity are provided in reference articles by Van Genuchten (1980) and Mualem (1986). The required data input for these models are saturated hydraulic conductivity and water retention characteristics (primary drainage curves). Because these data are avail able on the test samples, parameters can be calculated that describe the unsaturated water characteristics of these materials.

6.2.3 Water Retention

Water retenti on characteristics were measured using three different techniques. The technique used depended on the applied pressures or soil moisture conditions of the sample. Procedures described by Klute (1986) were followed. For pressures in the very wet range (0 to 150 cm), hanging water columns were used; for the drier range (510 to 4080 cm), pressure plate extractors (Soil Moisture Equipment Corp., Santa Barbara, Cal iforni a) were used. For drier soils, samples were composited, and the water retention was measured as a function of the sample relative humidity (using a CXl sample changer from Decagon Devices, Ltd., Pullman, Washington).

Samples from the hanging water columns were packed to a density of 3 1.37 g/cm in cylinders 3 cm high and 5 cm in dia. The samples were placed

on the porous plate in Buchner funnels. The funnels were connected to outflow tubes that regulated the head values. The water loss at each head was measured by weighing the sample in the ring. The samples were allowed to remain saturated for 48 hours before the excess water was drained at 10 cm. The pressure head was increased each time after drainage had ceased, and the sample was weighed. After reaching equilibrium at 150 cm pressure, the samples were weighed and oven-dried to determine the water content.

Water retention characteristics were measured at 510 cm, 1020 cm, and 4080 cm of pressure using a pressure plate extractor. A 1-bar pressure plate (one that has a bubbling pressure or air-entry value in excess of 1 bar of pressure) was used for the 510-cm tests, while a 5-bar plate was used for the other tests. Equil i brium water contents were obtained by packing the samples

3 in container cylinders (density, 1.37 g/cm ) on a porous ceramic plate where they were saturated for 48 hours. On complete saturation, the plate was placed in the extractor vessel and the internal air pressure raised to the desired test level. Equilibrium was reached when drainage creased. At the end of each pressure run, each sample (run in triplicate) was carefully weighed and oven-dried to determine the moisture content at that pressure level. This procedure is described in more detail by Klute (1986).

We attempted to use a 15-bar pressure plate for sampling at 15,300 cm applied pressure. The data indicated that the samples did not equilibrate

w i t h t h e app l i ed pressure (i.e., t h e water contents were h igher than the

4080-cm t e s t s ) , so these data were n o t used. Apparent ly t h e 15-bar p l a t e has

such a low pe rmeab i l i t y t h a t e q u i l i b r i u m i s n o t achieved i n a reasonable

(2 - t o 3-week) t e s t per iod . S o i l samples w i t h a very d r y water - re ten t ion

c h a r a c t e r i s t i c ( i .e., w i t h water contents lower than " w i l t i n g p o i n t " t o those

a t a i r - d r y cond i t i ons ) were composited, and r e l a t i v e humid i ty o f t h e s o i l was

determined by t h e dew-point method us ing a CX1 sample changer.

6.3 RESULTS

Table 6.3 shows t h e measured sa tura ted hydraul i c c o n d u c t i v i t y values,

t h e sa tura ted water contents, and t h e ca l cu la ted p o r o s i t i e s f o r samples t h a t 3 were packed t o an average dens i t y o f 1.37 g/cm . There i s more than one

order o f magnitude d i f f e r e n c e i n sa tura ted hyd rau l i c conduc t i v i t y , even f o r

these c a r e f u l l y packed cores. The data show t h a t t he samples were n o t f u l l y 3 sa tura ted t o t h e t o t a l p o r o s i t y o f 0.496 cm /cm3, which was ca l cu la ted from

p a r t i c l e and b u l k dens i t i es .

TABLE 6.3.

Sampl e

D02-5-10 002-5-16 D04- 1-04 D04-1-10 D05-5-03 D07-1-04 D08-2-15 D09-7-01 009-7-02 D09-7-05 D10-4-04 D l l -7 -06 D l l -7 -08 D12-4-14 D13-3-08 D14-3-04

Hydraul i c Conduct iv i ty , Saturated Water Content, and Sa tu ra t i on Ra t io

Hydraul i c Saturated Conduc t i v i t y Water Content Po ros i t y Satura t ion

(cm/sec) ( vo l /vo l l ( vo l /vo l l Rat io

Tab le 6.4 shows t h e parameters r e s u l t i n g f rom curve f i t t i n g o f

1 aboratory-measured wate r r e t e n t i o n and hydrau l i c c o n d u c t i v i t y data. A1 1 t h e

da ta were f i t t e d s imu l taneous ly t o o b t a i n t h e average parameters shown a t t h e

bottom o f Table 6.4. These parameters a r e c u r r e n t l y be ing used i n UNSAT-H

model s i m u l a t i o n s t o r ep resen t t h e f i n e s o i l i n t h e FLTF l y s i m e t e r s . Data

w i l l soon be a v a i l a b l e f rom t h e FLTF so t h a t a range o f t e s t cases can be

analyzed and compared w i t h s i m u l a t i o n r e s u l t s . The unsa tu ra ted h y d r a u l i c

c o n d u c t i v i t y p l a y s an impo r tan t r o l e i n t h i s t ype o f ana l ys i s . The wate r

r e t e n t i o n c h a r a c t e r i s t i c s l i s t e d i n Tables 6.5 and 6.6 show t h a t t h e s o i l

e x h i b i t s water s to rage va lues t h a t a re over 42 cm o f water p e r 1.5-m dep th

f o r a l l samples. T h i s va lue was computed by averaging t h e measured d i f f e r -

ences between t h e wate r con ten ts assoc ia ted w i t h 100-cm t e n s i o n and 4080-cm

TABLE 6.4. C u r v e - F i t t i n g Resu l ts f o r F i e l d Lys imeter Test F a c i l i t y (FLTF) Labora to ry Water Re ten t ion and Hyd rau l i c C o n d u c t i v i t y Data

Sampl e D02-5-10

er (cm3/cm3) 0- Alpha / l /cm) 0.0167 0.496 0.0118

or = Residual wa te r con ten t os = Sa tu ra ted wate r con ten t Alpha and n = C u r v e - f i t t i n g parameters Ks = F i t t e d s a t u r a t e d water con ten t tt Parameters c u r r e n t l y be ing used f o r f i n e

s o i l h y d r a u l i c p r o p e r t y d e s c r i p t i o n i n UNSAT-H b a r r i e r s imu la t i ons .

TABLE 6.5. Water Retention Values for Selected Field Lysimeter Test Facil i ty (FLTF) Soil Sampl es Vol umetri c Water Content (vol/vol )

Head (cm) Hz0

Volumetric Water Content (vol/vol )

Head D09-7 D09-7 D10-4 D l l - 7 D l l - 7 D12-4 D13-3 D04-3 (cm) Hz0 -02 -05 - 04 - 06 - 08 -14 - 08 - 04

(a ) Water content value a t zero pressure computed on basis of total porosity of sample.

tension. These were somewhat arbi t rary selections reflecting the upper and

lower l imit of stored water for th i s s o i l . Field measurements are currently

being made t o confirm these values. This storage estimate of 42 cm i s more

than 2.5 times the ambient (16 cm) annual precipitation.

Additional laboratory sampling of water retention does not appear t o be

warranted a t the present time. The data are suff ic ient ly similar that

TABLE 6.6. CX1 (Relative Humidity Sensor Data for Composite Field Lysimeter Test Facility (FLTF) Samples)

Vol umetri c Water Content

(vol /vol ) Head (-cm)

analysis using any of the individual curves should reflect the response of the entire lysimeter system. Field data collection is an integral part of the program to assess the hydraulic properties of the lysimeter soils. Fur- ther field data collection is planned for this project. The field testing program will be described in detail in Section 7.0. In addition to water storage measurements, one of the key tests that-is planned for the FLTF is a direct measure of hydraulic conductivity using lysimeters D09-7 and Dll-7 (precipitation to breakthrough). These lysimeters will be used as large- scale permeameters where hydraulic conductivity will be measured by using a steady-state, constant-head method. These tests are scheduled to start in FY 1989. Plans are also being made to measure unsaturated hydraulic conductivities in the same lysimeters and to compare these tests with steady state measurements that are currently being run in the laboratory.

7.0 FIRST YEAR TESTS AND RESULTS

Objectives of the initial tests were to measure water balance on test barriers,. assess hydraul i c performance, obtain data for cal i brati on of a simulation model, and identify possible design problems. Results reported here are from tests done between November 1987 and mid-June 1988. These results were gathered mainly from tests eval uating barrier hydraul ic performance and tests eval uating barrier design.

Tests required calibration and crosschecking of measurements and instruments. For example, water content and tension measurements were compared qualitatively. The water content measurements were taken using a neutron probe. The water tension measurements were taken using tensiometers. The soil desorption characteristic pairs were obtained from laboratory analyses of the McGee Ranch soil (see Section 6.0). Also, lysimeter weight changes were used quantitatively to refine the neutron probe calibration from measurements of soil moisture profiles.

Soil moisture tensions and contents during breakthrough in D09-7 and Dll-7 were compared qualitatively with those predicted from the soil moisture desorption characteristic curve. Thus, crosschecking of instruments and measurements was done to help assure the reliability of the protective barrier tests.

Observations and measurements are reported in the following sections.

7.1 WATER BALANCE

Water balance was tabulated for all lysimeters (Table 7.1). Water added by precipitation and irrigation equaled water lost by drainage and evapotranspiration, with the difference accounted as change in storage. The lysimeters are grouped according to treatment, which is described at the bottom of Table 7.1.

Discussion of detailed water balance and infiltration testing of lysimeters is separated into six topics:

1. drainage lysimeters leak tests

2. lysimeter drainage

TABLE 7.1. Water Balance (cm) for the Field Lysimeter Test Facility (FLTF) from November 1, 1987 to June 21, 1988

Treatment Lvsimeter Precip. Irriq. Drain. ET Storaqe

N - - Ambient precipitation V - - Vegetated surface B - - Bare surface

Ad - - Admixture of gravel (22% by weight) in top 20 cm 2N - - Twice average precipitation equals total water F - - Irrigate until breakthrough

DI - - Soil depth is 1.5 m - - Soil depth is 1.0 m.

3. water additions by rainfall simulator

4. weight changes measured by weighing lysimeters

5. neutron probe measurements of soil moisture

6. soil water tension measurements.

7.1.1 Drainaqe Lvsimeter Leak Tests

Satisfactory leak t e s t s were made a t the factory. After instal la t ion,

another leak t e s t was conducted. Results from t h i s t e s t indicated a need for

additional leak test ing and evaluation.

Three successive leak t e s t s were conducted during the winter months of

1987 and early spring of 1988. The resu l t s showed that long presoak and

drainage periods were needed to achieve reasonable precision. These leak

t e s t s produced more hydraulic pressure in the lysimeters than i s expected

under experimental conditions . Our resul ts indicate that lysimeters D02-5 and D06-6 may leak i f sub-

jected to pressures as great as those during the t e s t period. Apparent water

losses might also be the resul t of absorption into the porous rock or adsorp-

tion onto the dry soil because of d i s t i l l a t ion ( so i l s in D02-5 and D06-6 were

dr ie r than the other lysimeters during leak t e s t s ) . However, because the

lysimeters do n o t retain water under a hydraulic pressure, but instead are

allowed to drain freely, leakage caused by pressure i s unlikely. Also,

because D02-5 and D06-6 receive only ambient precipitation, they are n o t expected to yield drainage and, therefore, leakage occurring under hydraulic

pressure should not occur. See Appendix A .

7.1.2 Lvsimeter Drainaqe

As discussed in Section 2.0, lysimeters D09-7 and Dll-7 had water

appl ied unti 1 drainage occurred. Water accumulated in the f ine soi 1 unti 1

the soil was saturated a t the interface between the f ine soil and underlying

coarse sand. After saturation, water "breakthrough" occurred into the sand

and further into the underlying coarse materials, gravels and r iprap, causing

the lysimeter t o drain. During breakthrough, soil water just above the

boundary developed a positive pressure. Breakthrough drainage i s shown in

Table 7 .2 .

Water received by D09-7 and Dll-7 between day 310 in 1987 and day 173 in

1988 was 30.5 cm, raising the water content in the profi le a t breakthrough as

shown in Figure 7.1. The soil water content in the fine soil just above the

textural boundary, a t the 135-cm depth, exceed 40% by volume. This water

TABLE 7.2. Cumulat ive Drainage f rom Lys imeters D09-7 and D l l - 7

Drainage (cm H20)

Lvs imeter 6/6/88 6/ 14/88 6/2 1/88

DO9 - 7 0.38 0.84 0.99

D l l - 7 0.01 0.33 0.49

0

-20 -

-40 - -a- N o v ~ , 1987 DO9

-0- Nov 4, 1987 Dl1 + Jun 7, 1988 DO9

-60 - - --CI Jun 7, 1988 Dl1

E - 5 -80 - 8 n

-100 -

- 120 -

-140-

- 160 0 10 20 30 40 50

Water Content (~01%)

FIGURE 7.1. S o i l Mo i s tu re P r o f i l e s i n D09-7 and D l l - 7 on November 4, 1987 and June 7, 1988 (cm dep th versus volume %)

con ten t i s about 25% more wate r than was be ing r e t a i n e d by t h e s o i l 50 cm

above t h e t e x t u r a l boundary. Thus, t h e t e x t u r a l boundary ( f i n e s o i l / c o a r s e

sand) caus ing a c a p i l l a r y d i s c o n t i n u i t y appears t o be per fo rming acco rd ing t o

des ign .

Potential drainage problems discovered during tests to barrier failure included soil puddling, channeling, and frost heaving. When large amounts of water were applied to the soil surface, the soil tended to puddle (i .e., soil particles suspended by water are redeposited on the surface with the fine overlying the coarse particles). This may cause water to move into cracks or cavities, preferentially. The soil also had a tendency to channel, allowing the water to percolate downward in the profile more rapidly than predicted from soil properties. Frost heaving near the soil surface and along the container edge increased the possibilities for channeling. Some effort was expended to limit the effects of channeling. Backtamping of the soil (with the end of a 1- x 4-in. board or a shovel handle) was practiced on every channel cavity preceding water application. The effects of channeling were limited and apparently caused no premature failure of the barrier. Evidence for this conclusion is shown by simil ar performance of the barriers in D09-7 and Dll-7, despite their differences in channeling.

7.1.3 Water Additions bv Rainfall Simulator

The experimental design calls for selected weighing and drainage lysimeters to receive more water than average precipitation. Lysimeters D09-7 and 011-7 were to receive precipitation until barrier failure. Lysimeters D10-4, D12-4, D13-3, D14-3, W03-3 and W04-4 were to receive twice average precipitation.

A project management decision was made to change the wet treatment design to apply twice the long-term average precipitation. This decision was made because of abnormally low precipitation during the early part of 1988. Also, early results from barrier performance were needed. Twice average precipitation is shown in Figure 7.2 and Table 7.3. This change was made beginning March 14, 1988. The objective was to deliver the total amount of water needed by the middle and end of each month. Table 7.4 shows the actual and target amounts of precipitation to be received by the twice average treatment.

7.1.4 Weiqht Chanqes Measured bv Weiqhinq Lvsimeters

The following procedure was devised to certify the performance of the weighing lysimeter scales. Standard weights with calibration traceable to

N D J F M A M J J A S 0 N

Time (months beginning Nov 1 )

FIGURE 7.2. Twice Average P r e c i p i t a t i o n and Ac tua l Water App l i ed f rom November 4, 1987 t o June 21, 1988 (cm)

TABLE 7.3. Water Accumulat ion ( p r e c i p i t a t i o n p l u s i r r i g a t i o n ) Needed t o Achieve Twice Average P r e c i p i t a t i o n (cm water )

Dav Nov Dec Jan Feb Mar AD^ May Jun J u l Auq Sep Oct

1 0.0 4.4 9.0 13.6 16.6 18.5 20.5 22.9 25.7 26.4 27.6 29.2

16 2.2 6.7 11.3 15.1 17.5 19.5 21.7 24.3 26.0 27.0 28.4 30.6

3 1 - - - - - - - - - - - - - - - - - - - - - - 32.0

t h e Na t i ona l Bureau o f Standards (NBS) were p laced on t h e c e n t e r o f t h e s o i l

su r f ace o f each l y s i m e t e r i n 10 equal increments. A 1 - v o l t e x c i t a t i o n was

a p p l i e d by t h e CR7X d a t a l ~ ~ ~ e r ( ~ ) t o t h e f u l l b r i d g e on t h e t o r s i o n bars o f

t h e sca les . The v o l t a g e ou tpu t s f rom t h e t o r s i o n bars on t h e p l a t f o r m sca les

( a ) Campbell Scie,nt i f i c , Inc . , Logan, Utah.

TABLE 7.4. Total Water Deli e y from P r e c i p i t a t i o n and Appl ica t ion (cm) 1 a!

I r r i q a t i o n Total

23.9 30.5 16.8 27.7 23.9 30.5 16.7 27.6 16.7 27.6 16.7 27.7 16.4 27.3 16.4 27.3

( a ) Del i ve ry per iod was from 4 November 1987 through 21 June 1988.

were then read and recorded manually. (They may a l s o be recorded on t h e CR7X

da t a logge r on t h e 1500-microvolt range s e t f o r high r e s o l u t i o n . The vo l t age

s i g n a l s condi t ioned f o r f i n a l memory i n t h e da ta logger a r e mu1 t i p 1 ied by 1

and a -1 o f f s e t i s added. By programming t h e da ta logger i n t h i s manner, one

add i t i ona l d i g i t may be gained i n instrument r e s o l u t i o n i n t h e f i n a l s t o r age

of t h e da t a logge r . During s c a l e c a l i b r a t i o n , da t a logge r s should be s e t t o

read weight ou tput every 10 seconds and average s i x read ings each minute.)

Weights recorded manually should show maximum and minimum va lues mea-

sured . The da t a logge r d a t a were t r anspo r t ed from f i n a l memory i n the d a t a -

logger by te lephone l i n e t o t h e computer i n an o f f i c e bu i ld ing (Sigma V)

where t h e vo l t age s igna l was s t o r e d i n a d a t a f i l e a s t r ansmi t t ed .

The vo l t age d a t a were t ransformed by adding t h e 1 back i n , mu1 t i p l y i n g t h e sum by ten- thousand and f i t t i n g a r eg re s s ion l i n e through t h e transformed

vol tage-weight p a i r s over t h e c a l i b r a t i o n range by using t h e fol lowing

equat i on :

S = summation [(W - Wa)(V - Va)]

summation [ ( V - Va)(V-Va)]

where S = s l o p e of t h e r eg re s s ion l i n e

W = c a l i b r a t i o n po in t weight added

Wa = average of a l l weight added

V = c a l i b r a t i o n p o i n t t ransformed vo l tage

Va = average transformed vo l tage obta ined from

The s lope o f t h e regress ion l i n e was used i n t h e f o l l o w i n g equat ion t o

ob ta in t h e i n i t i a l ca l i brated weight s tep f o r comparison w i t h measured

va l ues :

Wo = S (Va - Wa/S) (1-3)

where Wo i s t h e beginning c a l i b r a t e d weight s tep be fore t h e f i r s t weight i s

added. A l l t ransformed vo l tage readings were mu1 t i p 1 i e d by the s lope and the

v a r i a t i o n i n sca le performance was obta ined by comparing measured weight

values w i t h standard weights added. Dev ia t ions o f each scale weight from the

c o r r e c t weight va lue were obtained from Equation 1-4:

D = W - (Wo t n Wc) (1 -4)

where D = t h e d e v i a t i o n o f t he observed weight from the c a l i b r a t e d weight

W = t h e observed weight a t t h e c a l i b r a t e d weight s tep (Wo + n*Wc)

n = t h e number o f weights added

Wc = t h e c a l i b r a t i o n weight s i ze .

Ten, 100- lb weights were used du r ing the f i r s t c a l i b r a t i o n by t h e

Hanford Engineering Development Laboratory (HEDL) ; so, n = 10 and Wc = 100 i n

t h a t case. Each o f ten, 100- lb weights was app l ied i n t u r n i n a s tack on t h e

middle o f t he s o i l sur face on each weighing l y s i m e t e r and the r e s u l t i n g

vo l tage read ing was recorded. Then the weights were removed i n opposi te

sequence. Dev ia t ions obtained over t he range o f c a l i b r a t i o n were p l o t t e d

w i t h respect t o a zero reference l i n e t o d i s p l a y scale performance. Manu-

f a c t u r e r t o le rance i s +/- 0.02%, which i s 3 1b i n 15,000. Accuracy, p r e c i -

s ion, and hys te res i s are d isp layed i n F igures 7.3 through 7.6. We noted t h a t

W01-1 was 3 1 b beyond to le rance a t t h e 1000-1 b a d d i t i o n p o i n t , and W03-3 had

a 3 0 - l b hys te res i s on t h i s shor t i n t e r v a l t e s t . A graph o f t h e data from

FIGURE 7.3. Weighing Lysimeter W01-1 Cal i bration Results (deviations in pounds versus weight added)

8

6

4

2

B U)

o +Weight (min) - 0 + Weigh (w)

A - Weigh (rrdn)

- -Weight (max)

- * 0

0 0 0

FIGURE 7 .4 . Weighing Lysimeter W02-2 Calibration Results (deviations in pounds versus weight added)

7.9

6

4

2 - P- E .g 0 .I x

-2

-4-

-6

0

g .Q 5 o f - 8 ; i t o , - .-

d -2

4

6 -

8

Test Weight Load (Ib)

-

-

- 0

$ 3 A $

O 8 0

i? : A % ; : $ g - o O

B 0 0 0

-

o + Weighl (rnin) o + Welght (max)

- o - Weight (min) a -Weight (max)

I I I I 200 400 600 800

a B D a o

-

-

8 a I I I I

loo0

0 200 400 600 800 lo00 Test Weight Load (Ib)

Test Weighl (b)

30

20

- 10

P, rr P 5 8 0

-10

-20

FIGURE 7.5. Weighing Lysimeter W03-3 Ca l ib ra t ion Results (deviat ions i n pounds versus weight added)

A

0 b

8 6 8

A 0

A 0

0 . E 8 n

Q a

0 0 0 f,

+ Weight (min) + Weight (max)

o - Weight (min) a - Weight (max)

I I I I

q + Weighl (mn) + weigm (MX)

9 - Weighl (min) A - Weighl (max)

0 200 400 600 800 loo0

Test Weight Load (Ib)

FIGURE 7.6. Weighing Lysimeter W04-4 Ca l ib ra t ion Results (deviat ions i n pounds versus weight added)

each lysimeter was transmitted to HEDL for review and certification of each scale, and a calibration interval of 1 year was requested.

The effect of error from W01-1 may be disregarded because hydraulic breakthrough and drainage would occur about 300 1b before the error point was reached. The effects of error from W03-3 are unknown within its 30-1 b error range, but until the scale was rep1 aced, its weight changes were compared with those measured by the other weighing lysimeters and with volumetric measurements made using the neutron probe.

Weight data from all four weighing lysimeters were tabulated, graphed, and compared. General agreement between their calibrated weight changes shows similar performance as displayed in Figures 7.7 and 7.8.

A notable difference exists between water loss rates from lysimeters receiving ambient precipitation and those receiving twice average precipitation, especially during periods of surface drying. Spikes appearing in the graph were attributed to the temporary added weight of the neutron probe and operator. Upward offsets in the graphic data were traced through the laboratory record book to water, soil, or plant changes.

7.1.5 Neutron Probe Measurements of Soi 1 Moisture

Soil moisture was measured in two ways in each of the lysimeters at the time they were uncovered near the beginning of November 1987. One set of measurements was made at 5-cm depth intervals using the neutron probe, and the other set was made by gravimetric sampling from the top foot of soil near the center of each lysimeter. To measure the water content, soil samples were weighed, dried, and re-weighed. These water contents were multiplied by the appropriate bulk density measurements taken previously. Each volumetric water content was paired with the appropriate neutron probe reading, and a regression line was fit to the paired data to calibrate the neutron probe, as shown in Figure 7.9. The regression line was then adjusted to pass through a point representing oven-dried soil.

Weight changes caused by water gain and loss in weighing lysimeter W01-1 were used to refine the initial neutron probe calibration, resulting in

6950.-

A

m

6750-

N D J F M A M J J 1987 1988

T~me (months)

FIGURE 7.7. Weighing Lysimeter Weight Record For W01-1 and W02-2 from Day 310 o f 1987 t o Day 166 o f 1988

7450 4 6500 N D J F M A M J J

1987 1988 Time (month)

FIGURE 7.8. Weighing Lysimeter Weight Record For W03-3 and W04-4 from Day 310 o f 1987 t o Day 166 o f 1988

NP Counts

FIGURE 7.9. Neutron Probe Calibration (soil moisture volume % versus neutron probe counts)

the dashed line in Figure 7.9. This process of refinement is continuing,

using data from all four weighing lysimeters.

Following calibration, the raw counts taken with the neutron probe may be converted to volumetric water contents for comparisons. Water content profiles developed from neutron probe measurements in weighing lysimeter W01-1 are shown in Figure 7.10, where two profiles are displayed.

The difference between these two profiles should correspond to changes in water weight measured by W01-1 over the same time. Disagreement indicates one or more of the following: 1. neutron probe measures moisture in an unusual way 2. neutron probe calibration is inaccurate 3. the weighing lysimeter scale calibration is inaccurate.

While all three factors may contribute to disagreement, the FLTF disagreement

is small as shown in Figure 7.11.

The first source of error may occur as water accumulates either on the soil surface or as drainage at the bottom of the profile. The second source

FIGURE 7.10. Soi l Moisture P r o f i l e s i n W01-1 as Measured by Neutron Probe (volume X versus cm depth)

Julian Date

FIGURE 7.11. Gain or Loss i n Water Content Measured by Neutron Probe and Weighing Lysimeter (cm gain or loss versus time by Jul i an date)

of error results if soil that influences the neutron probe reading is not adequately sampled during calibration or if too few readings are taken to account for variations in radioactive decay.

The third source of error may result if the weighing lysimeter is not

removed from its scale to make a full -scale cal ibration. This source of

error was minimized by calibrating the unloaded scale with standard weights

from 0 to 7000 1 b and then calibrating the loaded scale over the range of use expected. Calibration over a range from ambient to ambient t1000 1b is more

than the current ambient use range and is expected to be adequate for this year. Next year, we plan to use small load cell s cal ibrated against proving

rings to cover the full load range. This calibration method is considered more accurate than the weight cal i bration method, which uses 1000-1 b weights.

Changes in soil water contents measured by the neutron probe should

agree with changes in weight measured by a weighing lysimeter. Figure 7.12 shows the variation between neutron probe and weighing lysimeter measurements

for W01-1 for November 5, 1987 through June 6, 1988. Figure 7.13 shows soil water storage for all lysimeters.

Jul~an Date

FIGURE 7.12. Difference Between Neutron Probe and Weighing Lysimeter Measurements (cm of water)

N D J F M A M J J 1987 1988

N D J F M A M J J 1987 1988 + D l 3-3

-A- D l 4-3 + WL3-3

I 1 22 I 1 I 1 I I i I I

N D J F M A M J J 1987 1988 + D02-5 -- 005-5

22 4 I I I I I I 1 I

N D J F M A M J J 1987 1988

20 N D J F M A M J J 1987 1988 + D10-4

-A- D 1 2-4 + WL4-4

N D J F M A M J J 1987 1988 + D03-6

---t-- D06-6

FIGURE 7.13. Storage Changes in Soil Moisture for All Lysimeters from November 4, 1987 to June 7, 1988 (cm of water versus date)

7.1.6 Soil Moisture Tension Measurements

Tension measurements above 1 m were avoided during the fall and winter months because of the risk of freezing and breaking the tensiometers. How- ever, tensiometers at 1 m and l .5 m were serviced and monitored beginning 22 December 1987.

Most tensiometers were sensing sufficiently dry soil to cause them to fail. However, drainage lysimeters D09-7 and Dll-7 yielded significant performance data during the latter part of their transition to barrier breakthrough. Table 7.5 shows soil moisture tensions from mid-May through mid-June in D09-7 and Dll-7.

The negative values in the table indicate water pressure above the textural boundary. Note the return to negative pressure (tension) fol lowing drainage and a corresponding decrease in rate of drainage as shown in Table 7.2, for D09-7.

Data from weighing lysimeters, neutron probe, tensiometers, and drainage measurements appear to be in reasonable agreement; the textural breaks in D09-7 and Dll-7 are performing according to design.

7.2 VEGETATION RESPONSE

Establishment and growth of plants in the soil layer of the barrier system is important for erosion control, recycling of meteoric water (rainfall, snowmelt) to the atmosphere, and for aesthetics. Evapotranspiration

(ET) of water by vegetation growing on the barrier surface will reduce the amount of water available to drain through the system. To evaluate the effects of vegetation on the water balance within the barrier system, plants

TABLE 7.5. Soil Moisture Tension (cm of water at 135 cm depth)

Date Lvsimeter 5/17 6/2 6/7 6/15 6/22 DO9 - 7 5.7 6.8 -2.3 1.7 6 -8

Dll-7 8.1 -6.1 -1 .O 2.0 7.1

have been taken from the McGee Ranch (see Figure 6.1) and transplanted into selected lysimeters as discussed in Section 2.2, where the seven treatments used in the FLTF were described.

7.2.1 Veqetation Establishment

The species transplanted to the lysimeters were chosen from the shrub-

dominated plant community growing in fine soil at the McGee Ranch site. This site has been described previously as the location for the fine soil material used in the lysimeters at the FLTF (Last et al. 1987). On some areas of the McGee Ranch site where farming and surface disturbance have occurred, a plant community of annual grass and weeds dominates. However, the presence of shrubs is believed to indicate climax conditions (Daubenmire 1970) and may be more representative of the vegetation that might establish over barriers. Also, the perennial grass species and shrubs of a climax community are deeper-rooted species than the annual grasses and herbs. The ability of deeper-rooted plants to access stored moisture in the fine soil component of the system may be important to barrier performance.

The vegetation transplanted included the perennial grasses, Poa secunda (bluegrass) and Orvzo~sis hvmenoides (Indian rice grass); Bromus tectorum (cheatgrass), an annual grass; and the shrub Artemisia tridentata (sagebrush). These species were chosen because they, along with Gravia s~inosa (spiny hopsage) and Helianthus cusickii (Cusick's sunflower), compose the major portion of the vascular plant cover on undisturbed areas at the McGee Ranch. (a) Although spiny hopsage is one of the dominant shrubs in the mature plant community at the site, no individuals were transplanted because no seedlings or small young individual plants were found within the site.

In disturbed areas, cheatgrass, although an introduced species, is the major component of the community along with other weedy annuals. Cheatgrass readily establishes in any area disturbed by fire, grazing, or anthropogenic

(a) Kirkham, R. R., S. 0. Link, and J. L. Downs. 1986. Characterization of Plant and Soil Parameters for Estimatinq Evapotrans~iration at Fine Soil Sites . Letter Report prepared by Pacific Northwest Laboratory, Ri chl and, Washington, for U. S. Department of Energy and Rockwell Hanford Operations.

(human-caused) mechanisms, and almost c e r t a i n l y w i l l be a s i g n i f i c a n t species

i n any p l a n t community t h a t i s es tab l ished as p a r t o f t h e p r o t e c t i v e b a r r i e r

system.

P lan ts were t ransp lan ted t o the lys imeters du r ing t h e f i r s t week o f

November (November 4 , 5, 6, 1987), immediately a f t e r removing the p l a s t i c

covers. At t h i s t ime o f year, t he perennia l grasses were completely sene-

scent and dormant. The grasses were excavated i n clumps, r e t a i n i n g as much

s o i l around the r o o t systems as possib le. I n add i t i on , the cryptogam l a y e r

t h a t covers a l a r g e p o r t i o n o f t he i n t e r p l a n t spaces was re ta ined w i t h t h e

p l a n t ma te r i a l . The p l a n t ma te r i a l was t ranspor ted i n conta iners t o t h e FLTF

t h e same day and rep lan ted i n t h e lys imeters . Because cheatgrass seeds were

abundant i n the s o i l and l i t t e r excavated w i t h the perennia l grasses, no

i n d i v i d u a l s were t ransp lan ted o r d i r e c t l y seeded on the lys imeters .

Small sagebrush seed1 i ngs were excavated, t ransported, and p l anted i n

t h e same manner as the grasses. When t ransp lan t i ng the sagebrush, i t was

important t o ensure t h a t o r i g i n a l s o i l was kept w i t h t h e r o o t i n g system t o

r e t a i n mycorrh iza l assoc ia t ion necessary f o r t he establ ishment and growth o f

t h e shrub. Because the s o i l s i n t he lys imeters were a t a h igher moisture

content ( > I 5 ~ 0 1 % ) than s o i l s under ambient cond i t i ons ( < l o vol%), i t was no t

necessary t o i r r i g a t e the t ransp lan ted vegetat ion t o ensure t h a t i t would

es tab l i sh .

7.2.2 Phenoloqv and Observations

The phenology and growth o f vegeta t ion on the l ys ime te rs were observed

du r ing the spr ing 1988 growing season and compared w i t h observat ions o f vege-

t a t i o n growing on the McGee Ranch f i n e s o i l s i t e . A l l o f t he t ransp lan ts on

t h e l ys ime te rs except one sagebrush seedl ing surv ived and grew v igorous ly .

Because the s o i l s i n t he l ys ime te rs were much we t te r than s o i l s a t t he McGee

Ranch s i t e (F igure 7-14), t he t i m i n g o f t he phenological stages o r pheno-

phases (Table 7.6) (French and Sauer 1974) o f p l a n t development was d i f f e r e n t

f o r t h e two s i t e s . However, t he onset o f a c t i v e p l a n t growth and germinat ion

o f cheatgrass seeds occurred a t r e l a t i v e l y the same t ime i n l a t e February and

e a r l y March on both the l ys ime te rs and a t t he McGee Ranch s i t e (F igure 7.15).

Bluegrass growing on the l ys ime te rs was green and a c t i v e w i t h 5 t o 7 cm o f

0

-50 - March 27. 1988

-100 -

-150-

4

5 -200- \

FIGURE 7.14. Comparison o f S o i l Mo i s tu re P r o f i l e a t McGee Ranch S i t e and a t F i e l d Lys imeter Tes t F a c i l i t y a) S o i l Mo i s tu re P r o f i l e i n March a t t h e Two S i t es , b) S o i l Mo i s tu re P r o f i l e i n June/July a t t h e Two S i t e s

- f a g -250

-300

-350

-400

-50 -

-100 -

- 5

\ 4

March 18. 1988

- I I

4 McGee - FLTF Ambient Preclp Vegetated

- FLTF Twice Average Precip Vegetated

- I I I I I I I I I I I

- f -200 n :

-250

-300

-350

-400

0 2 4 6 8 10 12 14 16 18 20 22 24

So11 Water Content (~01%)

- \ June 29. 1988

- 'Y

- i

o McGee - FLTF Ambient Precip Vegetated

FLTF Twice Average Precip Vegetated

I I I I I I I I I 0 2 4 6 8 10 12 14 16 18 20

Soil Water Content (~01%)

TABLE 7.6. Definitions of 14 Phenophases for Short Grass Prairie Species After French and Sauer (1974)

Phase Number

1

2

3 4

5

6

7

8

9

10

11

12

13

14

Pheno~hase Descri ti on

Pre-emergence growth/wi nter dormancy

Fi rs t vis ible growth

Firs t 1 eaves fu l l y expanded

Middle leaves fu l ly vis ible

Fi r s t 1 eaves senescent; middl e 1 eaves ful ly expanded

Late leaves fu l ly expanded

Developing f loral buds; middl e-1 ate vegetative

Mature f loral buds; 1 ate vegetative

Floral buds and open flowers

Buds, flowers, and green f r u i t

Buds, flowers, green f r u i t , and ripe f r u i t

Green f r u i t and ripe f r u i t

Ripe f r u i t and dispersing seeds

Flowering-induced dormancy

shoot growth on March 5. Bluegrass had in i t ia ted growth a t the McGee Ranch

s i t e on March 2 , 1988, and was green and active with about 5 cm of new

growth.

Phenological changes are greatly influenced by soil water as plants

progress toward senescence during the growing season (Sauer 1978). By mid-

May 1988, the bluegrass had se t seed and senesced a t the McGee Ranch s i t e ,

b u t the bluegrass on the FLTF s t i l l showed active growth. Cheatgrass had also se t seed and senesced by mid-May a t the McGee s i t e while growth of

cheatgrass was s t i l l quite vigorous on the lysimeters a t that time. In fac t ,

a secondary growth stage of cheatgrass occurred on the lysimeters as l a t e as

July 1, 1988, with new green shoots and t i l l e r s showing through plants com-

pletely senesced. Figure 7.15 shows the difference in phenological develop-

ment of bluegrass and cheatgrass a t the McGee Ranch s i t e and on the lysim-

e te rs using the convention of French and Sauer (1974).

I t appears the extra moisture available in the soil profiles in the

lysimeters had allowed the lysimeter vegetation to remain vigorous longer and

FIGURE 7.15. Comparison o f Phenol ogi c a l Development o f a ) Bromus tectorum and b) Poa secunda a t McGee Ranch and F i e l d Lysimeter Test F a c i l i t y (FLTF)

produce more biomass than comparably sized plants in the natural community.

In particular, new shoot growth of sagebrush was greater on the lysimeters

(mean of 22 .3 + 4 . 2 cm) than new shoot growth of sagebrush a t the McGee Ranch

s i t e (mean of 6.5 2 1 . 3 cm) . Leaf density of the transplanted sagebrush was

a1 so significantly greater. Sagebrush growth on the lysimeters continued

vigorously without ephemeral leaf drop and senescence through the month of

May and into July, while sagebrush a t the McGee s i t e began to lose ephemeral

leaves in l a t e May. In addition, the sagebrush a t the McGee Ranch had i n i t i -

ated f loral stems and were heavily budded early in July, while sagebrush in

the lysimeters showed no evidence of f loral in i t ia t ion .

Indi an ricegrass persi sted without significant senescence and without

seed drop into the month of July on the lysimeters, while a t the McGee Ranch

s i t e the ricegrass persisted throughout the m o n t h of June, b u t began to

senesce during June and dropped seed early in July.

The phenological development of a l l of the grasses seems to be affected

by the available soil water. The avai labi l i ty of soil water on the lysim-

e te rs allowed the grasses t o delay seed set and flowering-induced dormancy

re la t ive to the grasses in the McGee Ranch community. However, i t i s in te r -

esting to note that the bluegrass on the lysimeters began t o senesce and

deter iorate during early June, even on the lysimeters, where soil water was

not a limiting factor to growth of the grass. In addition, most of the

cheatgrass on the lysimeters se t seed and senesced during June as well, again

while the avai labi l i ty of soi l moisture did not appear to be a limiting

factor . A number of other environmental factors such as temperature, length of day, solar radiation, and water s t ress resulting from increasing r o o t

resistance with age may also affect phenological development, even though

soil moisture may be adequate (Kramer 1983).

Phenology of the lysimeter vegetation will continue to be observed to

evaluate the e f fec ts of soi l water avai labi l i ty on plant development and

growth. Other measures of plant growth such as leaf area, root growth and

density, pl ant/soi 1 water re1 ations, and gas exchange wi 11 be considered.

The l ys ime te rs prov ide a unique oppor tun i t y t o study t h e response o f t h e

vegeta t ion t o d i f f e r e n t sur face covers (g rave l admix sur face) and t o d i f -

f e r i n g c l i m a t i c regimes.

8.0 COLLECTION AND STORAGE OF DATA FOR THE

FIELD LYSIMETER TEST FACILITY

Data f rom t h e FLTF a re c o l l e c t e d and documented i n one o f two ways:

1) c o l l e c t e d and recorded manual ly, such as f i e l d observa t ions and l a b o r a t o r y

data, and 2) ga thered us ing computers, such as da ta rece i ved f rom sensors

connected t o t h e da ta loggers o r da ta r e s u l t i n g f rom computer s imu la t i ons .

The key i n f o r m a t i o n f rom these da ta s e t s i s s t o red on t h e Hanford P r o t e c t i v e

B a r r i e r s (HPB) M ~ C ~ O V A X ( ~ ) . A l l o f these da ta a re s to red us ing R S / ~ ( ~ ) s o f t -

ware except UNSAT-H model outputs , which a re s to red as b i n a r y o r t e x t f i l e s .

8.1 DATA COLLECTION

The types o f da ta c o l l e c t e d f rom t h e FLTF a re l i s t e d w i t h t h e c o l l e c t i o n

method i n Table 8.1. Data c o l l e c t e d manual ly are recorded i n l a b o r a t o r y

r eco rd books and en te red manual ly i n t o t h e FLTF database.

The c o l l e c t i o n o f da ta by t h e da ta logger i s c o n t r o l l e d by user -

generated programs. The da ta c o l l e c t e d d i r e c t l y by t h e da ta logger i n c l u d e

read ings f rom weigh ing l y s ime te rs , weigh ing l y s i m e t e r p l a t f o r m scales, and

temperatures. Thermocoupl e psychrometers a re connected t o t h e data1 oggers,

b u t these da ta have n o t been analyzed. A sample program l i s t i n g i s p rov ided

i n Appendix B. Data c o l l e c t e d by t h e da ta loggers a re t r a n s m i t t e d automat ic-

a l l y on a d a i l y schedule v i a te lephone connect ion t o a f i l e on an

IBM PC/AT(C) personal computer (PC) i n t h e l a b o r a t o r y . Th i s da ta f i l e i s

copied t o a master f i l e on t h e PC, sor ted, and t r a n s m i t t e d t o t h e p r o j e c t

MicroVAX t h e same day. Th i s process i n v o l v e s us ing so f tware packages

developed s p e c i f i c a l l y f o r t h e Campbell S c i e n t i f i c (CSI) da ta loggers as

w e l l as s imp le command statements i n ba tch f i l e s . Examples o f t h e f i l e s

r e q u i r e d f o r us i ng t h e CSI sof tware, TERM and TELCOM, a re a l s o g i ven i n

( a ) MicroVAX i s a r e g i s t e r e d t r a d e name o f t h e D i g i t a l Equipment Corp., Maynard, Massachusetts.

(b) RS/1 i s a r e g i s t e r e d t r a d e name o f BBN Software Products Corp., Cambridge, Massachusetts.

( c ) IBM PC/AT i s a r e g i s t e r e d t r a d e name o f I n t e r n a t i o n Business Machines Corp., Armonk, New York.

( d ) Campbell S c i e n t i f i c Inc. , Logan, Utah.

TABLE 8.1. Parameters Measured at Field Lysimeter Test Faci 1 i ty (FLTF) and Method of Data Collection

Parameter Collection Method

Soil temperature Copper/constantan thermocouple connected to data1 ogger

Soil water potenti a1 Tensiometers read manually, thermocouple psychrometers connected to datalogger

Soi 1 moisture Neutron probe measurements taken manually Gravimetric samples taken manually

Weighing lysimeter Readings from scales connected to datalogger weights

Drainage Scale readings of weight of water taken manually

Vegetative cover, Observations and manual measurements phenology, and water use

Appendix B. Figure 8.1 illustrates the flow of data from the field to the HPB MicroVAX. Figure 8.2 shows how data coll ected manually and automatically are transmitted or entered, manipulated, and stored on the HPB MicroVAX and the FLTF database.

Note that the sorted data files transferred from the PC data collection station reside in a transfer account on the HPB MicroVAX. These files are

stored there until they can be read into RS/1 and plots generated to visually inspect data for errors or inconsistencies. The data are evaluated in graphic form because the quantity of data collected is so large that review of individual data points is not feasible.

8.2 FLTF DATABASE

As discussed, the data collected from the FLTF are stored using RS/1 software. The RS/1 package is an information handling system with advanced

statistical and graphic output capabilities to aid in data analysis. A num-

ber of RS/l procedures (simple command streams written in RPL, the command

language used by RS/l) have been written to read, manipulate, plot, and assist in manual entry of pertinent data. Listings of these procedures and a

short description of their use are included in Appendix C.

CSI Telephone Data Collection

Datalogger b Station Transmission (IBM AT)

Upload to VAX

+ Manual Hanford

Measurements Protective

Barriers MicroVAX

RS/1 Laboratory Database Analysis Results -

FIGURE 8.1. Data Flow from C o l l e c t i o n a t t h e F i e l d Lysimeter T e s t F a c i l i t y (FLTF) Through Transmission t o Laboratory

FIGURE 8.2. D e t a i l e d D e s c r i p t i o n o f Data Flow, Man ipu la t i on , and F i n a l Storage i n t h e F i e l d Lysirneter Tes t F a c i l i t y (FLTF) Database

Laboratory and Field Data

Automated Data Collection

(Data Logger) -

Neutron Probe Digital Readout

Unit

IBM AT System

- Telecommunications

Software to Transfer Data to MicroVAX

b

HPB MicroVAX

*

Keyboard Entry

b

A

+

Operating System Transfer Account -

RS/1 Procedures

FLT F RS/1

*

RS/1

Data Manipulation and Quality

CSI Telecommunications

Software

Assurance

Write Data

to File Sort and Transfer Data to File

B

File Management

Software b

Terminal Emulator Software

+

The RS/1 sof tware appl i c a t i o n f o r t h e database on t h e b a r r i e r s p r o j e c t

uses a simple se t o f use r -con t ro l l ed r e l a t i o n s h i p s t o organize and main ta in

t h e database. Although RS/l i s no t a r e l a t i o n a l database, r e l a t i o n s h i p s are

maintained by ca tego r i z ing t h e da ta by t ype i n t o s p e c i f i c sub -d i rec to r i es and

us ing a s t r i c t l y cons i s ten t nomenclature t o i d e n t i f y da ta sets. F igure 8.3

presents t h e d i r e c t o r y s t r u c t u r e and prov ides a d e s c r i p t i o n o f t h e contents

o f each d i r e c t o r y .

8.2.1 Automatical 1 v Co l l ected Data

Data f i l e s received from the data logger are read on an I B M PC/AT each

day as they are received. The data are sor ted according t o t h e t ime reso-

l u t i o n o f t he measurements and t r a n s f e r r e d t o the p r o j e c t MicroVAX. The

hou r l y f i l e s are read i n t o RS/1 on a t i m e l y bas is us ing a simple program

(RS/1 procedure) c a l l e d FLTFHREAD - 1. Th is procedure reads t h e da ta from t h e

opera t ing system f i l e i n t o an RS/1 t a b l e as shown i n Tables 8.2 and 8.3. I n

add i t ion , the procedure adds data t o several summary tab les , adds data t o t h e

graphs o f weighing l ys ime te r data, and generates p l o t s o f t he data. The pro-

cedure FLTFDREAD-1 i s used t o read i n d a i l y averages o f t h e da ta and add

these data t o summary tab1 es as we1 1.

8.2.2 Manual 1 v Co l l ected Data

The major p o r t i o n o f t h e manually c o l l e c t e d data cons is ts o f neutron

probe readings. These data are c o l l e c t e d and s tored on a d i g i t a l readout

u n i t i n t he f i e l d and logged i n the l abo ra to ry notebook. The readout u n i t ,

which conta ins a memory (s torage) , i s brought from the f i e l d , connected t o

the PC, and the data are then telecommunicated t o a f i l e on the computer

us ing a capture op t i on o f the software. This f i l e i s e d i t e d t o de le te some

nonessent ial l i n e s i n the f i l e and subsequently t ransmi t ted t o the p r o j e c t

MicroVAX. These f i l e s are named i n t h e f o l l o w i n g manner: 'F' t o i n d i c a t e

the FLTF s i t e ; 'day, month, year ' ; and an extension ' . da t f t o i n d i c a t e t h a t

t he f i l e has been ed i ted . For example, da ta c o l l e c t e d on June 10, 1988, a t

t he FLTF s i t e would be named as fo l l ows : FlOJUN88.DAT--indicating t h a t t h e

f i l e had been ed i ted and i s ready t o t r a n s f e r t o t he MicroVAX and read i n t o

RS/1.

FLTF Database

HPB MicroVAX -- Barriers Project

RSI Main Directory

FLTFNP Directory -- Contains Neutron Probe Data for the FLTF --

FLTFLX Directory -- Contains Datalogger Data for FLTF --

Subdirectories: NPDATA Moisture H20 cm

NPGRAPH Raw Count

Calib

FLTF Veg Directory -- Contains Vegetation Information for FLTF

Characterize Directory -- Contains Characterization Data Collected whi le Constructing FLTF --

Subdirectories: Partsize Density

H20 Content Dimensions

-- Contains TCP Data and Tensiometer Data for FLTF

FLTF Drainage Directory -- Contains Drainage Measurements for FLTF

FIGURE 8.3. O rgan i za t i on o f t h e F i e l d Lys imete r Tes t F a c i l i t y (FLTF) Database

TABLE

MODEL 503A-230 I D

441 442 443

444 445 446 447 448 4491 4492 4493

CD 441 0 4 441 11

44112 441 13 4412 4413 44141 44142 44143 4401 1 44012 44013 4402 44031 44032 44033 4404

STD

829 M17 0

0 0

0 0 0 0 0 5092 6039 9226 0 5174 5797 8379 0 0 4542 5214 7009 0 0 0 0

0 0 0 0

KDATA

1 Ml6 0

0 0

0 0 0 0 0 13071 1 7876 20787 0 12490 17995 19898 0

0 9477 12538 14262 8168 10349 11576 0

9302 1 1493 12215 0

Example o f

DEPTH

17 MI5 MI4 0 0

0 0 0 0

0 0 0 0 0 0 0 0 0 0 20948 18788 20367 18470 19541 17603 0 0 20105 17864 19672 17486 18614 17674 0 0 0 0 14330 13444 14546 13421 13885 13049 12197 11996 12299 12258 12072 11711 0 0 13111 12835 13486 13460 12914 12616 0 0

an E d i t e d F i l e o f Neutron Probe Data Ready f o r T rans fe r i n t o RS/l

TABLE 8.3 . Example of Neutron Probe Count Data as S to red i n an R S / l Table i n t h e Database

Neutron Probe Data f o r the FLTF S i t e a t 16-cm i n t e r v a l s on May 04, 1988

0 NOTE 1 ST. MEAN 2 END MEAN 3 DEPTH 4 001 6 002 6 003 7 004 8 006 9 006 10 007 6-23-88 STANDARD STANDARD ..........................................................................................................

1 Probe: 11703.00 11688.00 20 11662 11878 11832 11827 11900 11861 11990 2 603-OR 0 4919 4612 6319 6380 4362 6361 6708 3 H33116140 0 . 9 1 0 .81 -16 8963 8918 9927 9189 9382 9660 9778 4 Time: -30 10672 10268 10929 10298 11609 10918 10704 6 16 sac. -46 10937 10392 11216 10462 11168 11278 10467 6 Taken by: -60 11272 10494 12317 10184 10211 12079 10947 7 CJ KEMP -76 11486 10428 13042 11296 9964 12671 11232 8 Entered by: -90 11269 10889 11724 12104 10629 10719 11012 9 MJ KANYID -106 11102 10946 4996 11739 11664 4680 12000

10 by Computer -120 11696 11142 3996 12618 12181 3641 12648 11 Processed by: -136 11823 11602 12264 12367 12636 12 FLTFNP-2 -160 7094 6042 6464 6168 6472 13 Slope: -160 4691 4107 4400 6044 4206 14 0.0017 16 Offsot: 16 -1.4400

03 17 MSF-> 11646.60

03

0 NOTE 14 D11-S 16 D l 2 18 013 17 D14-S 18 W1-S 19 W82 20 W3-S 2 1 W04 6-23-88 ........................................................................................

1 Probe: 11878 11870 11882 11773 11889 11893 11790 11799 2 603-DR 10363 6667 6028 6086 6807 6043 6487 6108 3 H33116148 17638 12262 11068 11062 10339 10063 10434 11672 4 T i m : 17240 12677 11476 11999 11460 11266 11772 12904 6 16 roc. 17113 12488 11686 12008 11647 12099 12847 13223 6 Taken by: 17487 12394 12067 12863 11467 12128 12836 13471 7 CJ KEMP 17409 12684 12468 12873 11987 11944 13143 13800 8 Entered by: 17406 12024 12601 12696 11663 12648 13096 13684 9 MJ KANYID 17674 12084 12708 13049 11711 12822 12616 13861

10 by Computer 18614 12899 13494 13886 12072 12702 12914 14228 11 Processed by: 19898 13109 13467 14262 11676 11639 12216 14178 12 FLTFNP-2 8379 6664 6700 7009 7917 9236 13 Slope: 4684 4616 14 0.0017 16 Off sot: 16 -1.4400 17 MSF->

Note t h a t depth -168 cm f o r the Weighing Lysimeters i s a c t u a l l y depth -146 cm. Storage ca lcu la t ions use -146 cm as the in terva l and not -160 cm.

An RS/1 procedure cal led FLTFNP - 1 i s used t o read i n the neutron probe counts from the operating system f i l e . This procedure a lso performs simple manipulations of t he data t o organize the data in to d i f fe ren t d i rec tor ies (see Figure 8.3) and ca lcu la te percent moisture from the raw counts (Table 8.4), ca lcu la te storage using the calculated values of percent mois- t u r e (Table 8.5), add storage data t o summary t ab l e s fo r each lysimeter, and generate graphic data f o r each lysimeter (Figure 8.4).

Other data t h a t a re collected manually (i . e . , tensiometer data , drainage data , and any observations concerning the vegetation on the lysimeters) are a l so entered i n to RS/1 manually. No procedures have been developed a t t h i s time fo r manipulating these data s t ruc tures , but a procedure will be developed f o r entering t he drainage data and calcula t ing cumulative drainage through time. As shown in Figure 8.3, these data are stored in the d i r ec to r i e s according t o the part icul a r type data .

0 NOTE 6-23-88 -----------------

1 Probe: 2 603-DR 3 H33116140 4 Timo: 6 16 sac. 6 Taken by: 7 CJ KEMP 8 Entered by: 9 MJ KANYID

10 by Computer 11 Processed by: 12 FLTFNP-2 13 Slope: 14 0.0017 16 Of fset :

Co 16 -1.4400 w 17 MSF-> 0

0 NOTE 6-23-88 -----------------

1 Probe: 2 603-DR 3 H33116140 4 T i m : 6 16 see. 6 Taken by: 7 CJ KEMP 8 Entered by: 9 MJ KANYID

10 by Computer 11 Processed by: 12 FLTFNP-2 13 Slope: 14 0 .a017 16 Of fset : 16 -1.4400 17 MSF->

TABLE 8.4. Example o f Processed Neutron Probe Data i n t he F i e l d Lysimeter Test Faci 1 i t y (FLTF) : Cal cu l ated Percent Mois tu re

Neutron Probe Data f o r the FLTF S i t e a t 16-cm i n t e r v a l s on May 04, 1988

1 ST. MEAN 2 END MEAN 3 DEPTH 4 D01 6 D02 6 003 7 004 8 006 9 D06 10 007 11 D08 12 D09-S STANDARD STANDARD

.---------------------------------------------------------------------------------------------------- 11703.00 11588.00 20 18.37 18.76 18.67 18.67 18.79 18 .71 18.94 18.91 18.74

0 6.92 6.40 7.60 7 . 7 1 6.98 7.67 8.26 6.04 16.06 0 . 9 1 0 . 8 1 -16 13.80 13.72 16.44 14.18 14.51 14.80 16.18 14.67 32.92

-30 16.53 16.00 17.14 16.07 18.13 17.12 16.76 16.03 30.69 -46 17.15 16.23 17.63 16.33 17.63 17.73 16.36 16.98 30.14 -60 17.72 16.40 19.60 16.87 16.92 19.09 17.17 16.16 28.16 -76 18.09 16.29 20.73 17.76 15.60 20.10 17.66 16.77 28.92 -90 17.70 17.07 18.49 19.14 16.63 16.78 17.28 16.11 26.93

-106 17.43 17.17 7.06 18.62 18.20 6 .36 18.96 16.88 28.49 -120 18.27 17.60 6.36 19.84 19.27 4.68 19.88 17.67 31.78 -136 18.66 18.28 19.39 19.68 20.04 18.33 33.90 -160 10.62 8.83 9.63 9.01 9 .66 9.88 14.24 -160 6.36 6.64 6.04 7.13 6 .71 6 .00

Note t h a t depth -160 cm f o r the Weighing Lysimeters i s a c t u a l l y depth -146 cm. Storage ca lcu la t ions use -146 cm as the in terva l and not -160 cm.

TABLE 8.5. Summary Table Showing Mo is tu re Storage f o r Lys imeter DO1

Moisturo Storago i n D l i n Centimotors of Wator

1 04-NOV-87 2 02-DEC-87 3 18-DEC-87 4 08-JAN-88 6 21-JAN-88 6 06-FEB-88 7 18-FEB-88 8 02-MAR-88 9 18-MAR-88

.......................................... 1 20 2.733810 2.734830 2 0 0.891690 1.100280 3 -16 1.616400 1.766830 4 -30 2.194996 2.113906 6 -46 2.393896 2.332960 6 -60 2.489776 2.619866 7 -76 2.643030 2.613960 8 -90 2.616786 2.680616 9 -106 2.496160 2.644600

10 -120 2 .e l2940 2.630790 11 -136 2.921746 2.849680 12 -160 1.729876 2.412766 13 -160 0.674190 0.663480 14 16 TOT-76CM 11.338096 11.346610 16 75-l60CM 12.960686 13.781730

03 17 TOT STOR 27.914280 28.963360

w 18 TOT SOIL-S 24.288780 26.128240

w

0 10 20-APR-88 11 04-MAY-88

-------------- 1 20 2 0 3 -16 4 -30 6 -46 6 -60 7 -76 8 -90 9 -106

10 -120 11 -136 12 -160 13 -160 14 16 TOT-76CM 16 76-l60CM 17 TOT STOR 18 TOT SOIL-S

9.0 RECOMMENDATIONS

The FLTF is now completing its first year of operation. Results of initial monitoring of the lysimeters show expected differences in water balance that reflect the imposed surface conditions (i.e., bare surface, vegetation, gravel admixture, etc.). Data support the protective barrier concept in that a fine soil surface appears entirely adequate to recycle precipitation (both ambient and twice average precipitation) without allowing drainage, even under conditions where lysimeter surfaces are bare. While the present data support the concept of the protective barrier, the confirmation of barrier performance will require additional years of testing. To make all of the lysimeters fully functional and to optimize test results over the lifetime of the project, the following recommendations are made with respect to the operation of the FLTF in future years.

Continuity in Measurinq Water Bal ance. Continued collection of key data re1 ated to water bal ance parameters (i .e., precipitation, evapotranspiration, soil water storage, drainage) is essential to maximize the use of the FLTF. The data collection should continue uninterrupted for the lifetime of the project (at least another 5 years). Because the facility offers a unique capability for measuring each of the water bal ance parameters independently, conventional assumptions re1 ated to estimating drainage or recharge can be tested rigorously. The measurements necessary to calculate water balance for each of the treatments include: water storage, determined using neutron probe techniques; water storage and evapotranspiration, obtained using weighing lysimeter weight-change data; precipitation, determined using standard raingauges located at the HMS (adjacent to the facility); irrigation, measured with weighing lysimeters or with clearview raingauges placed directly on the lysimeters; and drainage, measured by direct weighing of outflow water from the bottom of the lysimeters. This continuous data set will allow us to assess the effects of climatic changes on temporal (daily, weekly,

monthly, seasonal, annual) variations of water balance for the test barrier configurations. The data sets will be used to calibrate and validate computer models needed to predict long-term performance of protective barriers at the Hanford Site.

It is recommended that the neutron probe measurements be continued on a biweekly basis and that irrigation be applied biweekly (except for below-freezing winter periods) to maintain the twice average precipi - tation treatments. It is a1 so recommended that the scale measurements of weight changes in the weighing lysimeters be collected continuously and at least hourly data be averaged and stored for each weighing lysimeter. These data should be transmitted automatically to the laboratory for storage in raw data files and subsequently processed and displayed graphically at least weekly.

Scale Cali bration. The two large platform scales, which are an integral part of weighing lysimeters W01-1 and W03-3, appeared not to perform to manufacturer specifications when they were calibrated early in 1988. These scales should be checked and recal i brated. If the scales still do not perform to desired specifications, they should be repaired or rep1 aced. Based on observations from the other two weighing lysimeters (W02-2 and W04-4), a weight resolution of less than 0.5 kg in 10,000 kg appears possible and the scales appear linear over the operational range of the lysimeters (0 to 8,000 kg). An annual calibration of these scales is recommended and is currently scheduled with the onsite cali- brat i ons 1 aboratory (HEDL) . Water Content Profiles with Gamma Scanner. When the gamma probe, which has been ordered from Troxler, Inc., is received, the scanning of water contents should be initiated. This probe was received in September 1988. After calibration tests and thermal stability checks, the gamma scanner will be used to measure the water contents in the upper 155 cm of each of the lysimeters. The gamma scanner measurements should resolve moisture contents more precisely than neutron probe measurements at the interface between fine soil and coarse sand.

4. Veqetation and Root Zone Monitoring. The establishment and response of the vegetation growing on the lysimeters during the period of November 1987 through June 1988 is documented in this report. Continued monitoring is recommended to assess growth and response of lysimeter vegetation to the particular soil and climatic variables of the selected barrier treatments. Phenological (growth-stage) responses should be documented at least on a monthly basis during the year and biweekly during the spring and summer growing seasons. Biomass production and gas exchange measurements should be made on a seasonal basis as should measurements of root growth and development. With the use of a down- well video camera, the root growth patterns of the plants growing on the lysimeters can be documented. The root growth patterns will provide a qualitative assessment of the root zone depth, expected areas of greatest plant water removal, and the time dependence of water extraction by plants.

We a1 so recommend that nonradi oact i ve (stab1 e) i sotope analyses be performed on selected pl ant tissues taken periodically from vegetation growing on the lysimeters. Although stable isotope analysis provides only a qua1 itative assessment of potential for water removal by plants, using isotopic tracers such as 1 5 ~ or measuring the 12c/13c ratios in plant leaves would provide confirmation of the plant nutrient and water- use efficiency status. Such measurements are currently being obtained on shrubs and grasses on the Hanford Site at several Arid Land Ecology study sites 'as part of a separate DOE program. This information, obtained for selected plant samples taken from the lysimeters, would be valuable in comparing the productivity and water use of plants growing on undisturbed landscapes to plants growing on protective barriers.

5. Visual Ins~ection of Barrier Confiquration. As part of the FLTF

original design, several 30-cm-di a by 300-cm-long clear plastic col umns were proposed to be inserted in the facility and located adjacent to the drainage lysimeter network. Original funding did not permit the pur- chase or the fil l ing of these demonstration lysimeters. We recommend

installation and filling of two plastic columns, one with vegetation and one bare, to show the configuration and 1 ayer sequence of materi a1 s in drainage lysimeters.

water Potent i a1 and Temoerature Prof i 1 es. Water potenti a1 (thermocouple psychrometer) and temperature (thermocouple) data collected to date have not been analyzed. These data will be analyzed during FY 1989, if funding is available. This analysis will require developing acceptability criteria for factory-cal i brated TCPs that have been placed in the soil profile. A probable procedure will be the use of factory calibrations to convert the voltage output from the TCPs into water potential (expressed in MPa pressure units) and then compare these data with neutron probe or gamma probe water content data for a field-measured water retention curve. These data can then be compared to the 1 aboratory-determined water potenti a1 -water content characteristics. Because TCPs are used primarily for dry soil conditions, data should be obtained during late summer or fall, at points in the soil profile where the soil water content is well below 13 vol% (i .e., where the water potential is below -0.2 MPa). During our tests, the soil was wetted to an average water content well above 15 vol%, and it took time for the soil to dry to a condition where the TCP data were meaningful. It would be very helpful to review the TCP data early in FY 1989 to assure that there is an adequate calibration procedure established. The thermocouple (TC) data can be analyzed in a more straight forward way because the data are output directly in temperature units. These data can be used to determine the effects of the various treatments on the thermal regime of the barrier. It is expected that these data will be compiled and reviewed in early FY 1989.

7. Leak Tests. Drainage lysimeters were leak tested and appear to be leak free, except for D02-5 and D06-6. While the tests show water losses in excess of 1 L from these two lysimeters, sources other than leakage could account for these measurements. These include vapor transport into dry soil and slow but measurable water imbibition by the basalt riprap. It is important to resolve this issue so drainage measurements

will be unequivocal, pa r t i cu la r ly f o r those lysimeters t ha t are expected

t o drain in future years. Effor ts should be expended during the next

year t o develop an improved t e s t f o r leakage.

10.0 REFERENCES

53 FR 12449-53. A p r i l 14, 1988. "Disposal o f Hanford Defense High-Level, Transuranic, and Tank Wastes- -Hanford S i t e , R i ch l and, Washington, Record o f Decis ion (ROD). " Federal Register .

Adams, M. R., and N. R. Wing. 1986. P r o t e c t i v e B a r r i e r and Warninq Marker Svstem Develo~ment Plan. RHO-RE-PL-35P, Rockwell Hanford Operations, R ich l and, Washington.

Brown, R. W., and B. P. Van Haveren. 1972. Psvchrometrv i n Water Re la t ions Research. Utah A g r i c u l t u r a l Experiment S ta t ion , Utah S ta te Un ive rs i t y , Logan, Utah.

Daubenmire, R. 1970. "Steppe Vegetat ion o f Washington. " Washington A g r i c u l t u r a l Experiment S t a t i o n Technical B u l l e t i n , 62: 1-131.

Fayer, M. J. 1987. Model Assessment o f P r o t e c t i v e B a r r i e r Desiqns: Par t 11. PNL-6297, P a c i f i c Northwest Laboratory, Richland, Washington.

Fayer, M. J., G. W. Gee, and T. L. Jones. 1986. UNSAT-H Version 1.0: Unsaturated Flow Code Documentation and A p ~ l i c a t i o n s f o r t he Hanford S i t e . PNL-5899, P a c i f i c Northwest Laboratory, R i ch l and, Washington.

Fayer, M. J., W . Conbere, P. R. He l l e r , and G. W. Gee. 1985. Model Assessment o f P ro tec t i ve B a r r i e r Desiqns. PNL-5604, P a c i f i c Northwest Laboratory, R ich l and, Washington.

French, N., and R. H. Sauer. 1974. "Phenological Studies and Modeling i n Grass1 ands. " I n Phenol oqv and Seasonal i t v Model i ng, eds. J. Jacobs, 0. L. Lange, J. S. Olson, and W. Wieser, 8:227-236.

Gee, G. W., and J. W. Bauder. 1986. " P a r t i c l e - s i z e Analys is . " I n Methods o f S o i l Analvsis, Par t 1, ed. A . Klu te , pp. 383-409. American Soc ie ty o f Agronomy, Madison, Wisconsin.

Gee, G. W., and T. L. Jones. 1985. Lvsimeters a t t he Hanford S i t e : Present Use and Future Needs. PNL-5578, P a c i f i c Northwest Laboratory, R ich l and, Washington.

H i l l e l , D. 1982. I n t r o d u c t i o n t o S o i l Phvsics. Academic Press. New York.

Kirkham, R. R., and G . W. Gee. 1987. F i e l d Lvsimeter Test F a c i l i t y f o r Pro- t e c t i v e Ba r r i e rs : Experimental Plan. PNL-6351, P a c i f i c Northwest Laboratory, Richland, Washington.

Klute, A. 1986. "Water Retent ion; Laboratory Methods." I n Methods o f S o i l Analvsis, Par t 1, ed. A. K lu te , pp. 635-660. American Soc ie ty o f Agronomy, Madison, Wisconsin.

Klu te , A., and C. Dirksen. 1986. "Hydrau l ic Conduct iv i ty and D i f f u s i v i t y : Laboratory Methods." I n Methods o f S o i l Analvsis, Par t 1, ed. A. K lu te , pp. 687-732. American Soc ie ty o f Agronomy, Madison, Wisconsin.

Kramer, P. J. 1983. Water Re la t ions o f Plants. Academic Press, New York.

Last, G.V., M.A. Glennon, M. A. Young, and G.W. Gee. 1987. P r o t e c t i v e B a r r i e r M a t e r i a l s Analvs is : F ine S o i l S i t e Charac ter iza t ion . PNL-6314, P a c i f i c Northwest Laboratory, Richland, Washington.

Mualem, Y. 1986. "Hydrau l ic Conduc t i v i t y o f Unsaturated S o i l s : P r e d i c t i o n and Formulas. I n Methods o f S o i l Ana lvs is Par t 1, ed. A. K lu te , ASA Monograph 9, American Soc ie ty o f Agronomy, Madison, Wisconsin.

Myers, D. R. 1985. Disvosal M a t e r i a l s Study. FHO-WP-EV-12P, Rockwell Hanford Operations, Richland, Washington.

Rawlins, L. S., and G. S. Campbell. 1986. "Water Po ten t i a l : Thermocouple Psychrometry." I n Methods o f S o i l Analvs is , Par t 1, ed. A. K lu te . American Soc ie ty o f Agronomy, Madison, Wisconsin.

Sauer, R. H. 1978. "A S imula t ion Model f o r Grassland Primary Producer Phenol ogy and Biomass Dynamics. " I n Grass1 and Simul a t i on Model, ed. G. S. I n n i s , pp. 55-87, Ecological Studies, Vol. 26, Springer-Verlag, New York.

U. S. Department o f Energy-Ri c h l and Operat ions O f f i c e (DOE-RL) . 1986. I n t e r i m Hanford Waste Manaqement Technoloqv Plan. U.S. DOE-RL, Richland, Washington.

U.S. Department o f Energy (DOE). 1987. "Disposal o f Hanford Defense High- Level, Transuranic and Tank Wastes." F ina l Environmental Impact Statement. EIS-0113. U.S. Department o f Energy, Richland Operations O f f i c e , R i ch l and, Washington.

Van Genuchten, M. T. 1980. "A Closed Form Equation f o r P r e d i c t i n g t h e Hydrau l ic Conduc t i v i t y o f Unsaturated S o i l s . " S o i l Sci . Soc. Am. J. 44:892-898.

11.0 BIBLIOGRAPHY

ASTM (American Soc ie ty f o r Tes t ing and Mater i a1 s) . 1985a. "Standard Method f o r Laboratory Determinat ion o f Water (Moisture) Content o f S o i l , Rock, and S o i l -Aggregate Mixtures. " I n Annual Book o f ASTM Standards, Sect ion 4: Construct ion, ASTM D2216-80, Vol. 04.08, ASTM, Phi ladelphia, Pennsylvania.

ASTM (American Society f o r Tes t ing and Mater ia ls ) . 1985b. "Standard Test Method f o r C l a s s i f i c a t i o n o f S o i l s f o r Engineering Purposes". I n Annual Book o f ASTM Standards, Sect ion 4: Construct ion, ASTM D2487-83, Vol . 04.08, ASTM, Phi ladelphia, Pennsylvania.

Blake, G . R., and K. H. Hartge. 1986. "Bulk Density." I n Methods o f S o i l Analvsis, Pa r t 1, ed. A. Klute, pp. 363-382. American Society o f Agronomy, Inc. , Madison, Wisconsin.

Daubenmire, R. 1959. "A Canopy-Coverage Method o f Vegetat ional Analys i s. " Northwest Sc i . 33:43-64.

Gee, G. W. 1987. "Pre l im inary Ana lys is o f t he Performance o f t h e P ro tec t i ve B a r r i e r and Marker System. Appendix M. " F ina l Environmental Impact Statement EIS-0113, U.S. Department o f Energy, Richland Operations O f f i ce , Rich1 and, Washington.

Kirkham, R. R., G. W. Gee, and J. L. Downs. 1987. An Ex~er imen ta l Plan f o r t h e F i e l d Lvsimeter Test F a c i l i t v (FLTF). PNL-6351, P a c i f i c Northwest Laboratory, Richland, Washington.

K lu te , A. 1972. "The Determinat ion o f the Hydrau l ic Conduct iv i ty and D i f - f u s i v i s i v i t y o f Unsaturated S o i l s . " S o i l Sc i . 113:264-276.

APPENDIX A

CHARACTERIZATION DATA FOR THE F I E L D LYSIMETER TEST F A C I L I T Y

APPENDIX A

CHARACTERIZATION DATA FOR THE FIELD LYSIMETER TEST FACILITY

IN IT IAL IN-PLACE LEAK TEST

I n i t i a l l e a k t e s t r e s u l t s a re recorded i n Labora to ry Record Book (LRB)

BNW-5137 on pages 23-39. Each l y s i m e t e r was covered w i t h p l a s t i c t o p reven t

evapo ra t i ve l o s s . Each l y s i m e t e r was f i l l e d and then d ra ined t o measure t h e

amount o f water r e q u i r e d t o cover t h e e n t i r e s l o p i n g f l o o r and t o measure t h e

amount o f water r e t a i n e d i n f l o o r depress ions f o l l o w i n g drainage. Each

l y s i m e t e r was then f i l l e d w i t h a measured we igh t o f water, rang ing f rom 150

t o 250 kg, and a l lowed t o s e t f o r approx imate ly a week. A t t h e end o f t h e

week, t h e water was d ra ined , weighed, and d iscarded.

Negat ive d i f f e r e n c e s shown i n Table A. 1 probab ly r e s u l t f rom con t inued

d ra inage o f water i n p u t t o f i l l depressions i n t h e t ank bottom and p o s s i b l e

f l e x i n g o f t h e t ank bottom. Est imated wate r l o s s by evaporat ion d u r i n g t h e

TABLE A.1. I n i t i a l In -P lace Leak Tes ts o f F i e l d Lys imeter Tes t F a c i l i t y Lys imeters i n A p r i l 1987 ( i n g)

0 Lvs imeter 1 I n ~ u t 2 Dra ined 3 D i f f e r e n c e

1 DO1 152999 152317 682 2 DO2 168462 167865 597 3 DO3 173159 172387 772 4 DO4 187257 185986 1271 5 DO5 175131 174640 491 6 DO6 157952 154447 3505 7 DO7 170898 167346 3552 8 DO8 162678 160283 2395 9 DO9 169269 169365 - 96

10 D l 0 17 1050 170495 555 11 D l 1 187058 188500 - 1442 12 D l 2 169926 169136 790 13 D l 3 178509 176672 1837 14 D l 4 173509 172332 1177

Negat ive d i f f e r e n c e s p robab ly a r e a t t r i b u t a b l e t o con t inued d ra inage o f water i n p u t t o f i l l t ank bottom.

t e s t p e r i o d (7 days) was 0.5 mm water f o r each l y s i m e t e r ( t h i s i s equ iva len t

t o 0.07 mm/d o r about 3% o f t h e maximum water l o s s o f 2 mm/d t h a t cou ld occur

under t h e c l i m a t i c cond i t i ons t h a t e x i s t e d du r ing t h e t e s t per iod) . The

0.5 mm (0.05 cm) water l o s s i s equ iva len t t o about 1.51 L o f water i n a

l y s i m e t e r 2 m i n d ia . The e r r o r i n t h i s est imate cou ld be as much as 100%

(i.e., as much as 3 L o f water l o s s by evaporat ion and as l i t t l e as 0.7 L).

The water l o s s da ta can be expla ined by evaporat ion i n a l l b u t two

lys imeters . It i s a l so poss ib le t h a t t he bottoms o f l ys ime te rs D06-6 and

D07-1 f l exed du r ing emptying and as a r e s u l t h e l d an apparent ly s i g n i f i c a n t

amount o f water. However, based s o l e l y on t h e l e a k t e s t da ta we cannot r u l e

ou t t he p o s s i b i l i t y o f a p inho le l e a k i n l ys ime te rs D06-6 and D07-1.

SUBSEQUENT IN-PLACE LEAK TESTS

The f i r s t o f t h i s se r i es o f t h r e e t e s t s was conducted us ing l ys ime te rs

D08-2 through D14-3. A b a r r e l was f i l l e d w i t h about 90 kg o f water and t h e

water t r a n s f e r r e d t o each l y s i m e t e r f o r 24 hours. The water was then dra ined

f o r 30 minutes back t o t h e b a r r e l , weighed and t h e weight recorded. The same

water was p laced back i n t he l y s i m e t e r f o r another 24 hours. A t t h e end o f

t h e 24-hour t e s t pe r iod t h e water was again dra ined f o r 30 minutes, weighed

and the weight recorded. The d i f f e r e n c e between i n i t i a l and f i n a l drainage

water weights was a t t r i b u t e d t o leakage.

I n t h e second t e s t we used t w i c e the amount water (180 kg) used f o r t h e

f i r s t t e s t . A 1-week presoak t ime was used. Lysimeters were dra ined f o r

1 hour and drainage water was weighed. The weighed water was then placed

back i n t h e same l ys ime te r and l e f t t he re 1 week. Then, each l y s i m e t e r was

dra ined f o r 1 hour, and t h e drainage water was again weighed (see

Table A.2).

The t h i r d t e s t was completed f o r l ys ime te rs D01-2 through D07-1. Lysim-

e t e r s D02-5 and D06-6 are the o n l y ones t h a t d i d n o t r e t u r n t h e e n t i r e

amount o f water f o l l o w i n g 3 days o f drainage. The t h i r d t e s t used a soak

t ime o f 1 month and a d r a i n t ime o f 3 days fo l lowed by a t e s t t ime o f 1 month

and a f i n a l drainage t ime o f 3 days. These th ree t e s t s fo l l owed s i m i l a r

procedures, bu t were d i f f e r e n t from t h e i n i t i a l i n -p lace t e s t .

Test r e s u l t s i n Table A . 2 show the n e t water i n p u t and drainage f o r

each l ys ime te r and the d i f f e r e n c e due t o leakage o r storage. Fol lowing t h e

d i f f e rence , a column shows how much add i t i ona l drainage occurred i n t h e f o l -

low ing 3 days. F i n a l l y , t h e r e i s a column showing how much d i f fer 'ence e x i s t s

between t h e amount o f water s to red and t h e amount d ra ined dur ing the f o l l o w -

i n g 3 days. Negative numbers i n t h i s l a s t column i n d i c a t e t h a t some o f t h e

water f rom the presoak was recovered.

Table A . 3 i s a record o f ma te r i a l weight p laced i n t h e lys imeters .

Table A . 4 shows t h e f a c t o r y c a l i b r a t i o n values f o r t h e thermocouple psychro-

meters placed i n t h e l ys ime te rs a t t h e FLTF. Table A . 5 extends from page A . 7

t o page A . 2 6 and shows dens i t y and moisture i n fo rma t ion f o r each drainage

lys imeter . Table A . 6 shows dens i t y and moisture da ta f o r t he weighing l ys im-

e ters . Table A . 7 conta ins a summary o f s o i l t e x t u r e s i n drainage lys imeters .

Table A . 8 presents a bas is f o r computation o f p a r t i c l e s i z e ord inates. F ig -

u re A . l shows a Proc tor dens i t y curve f o r the McGee Ranch s o i l used i n t h e

FLTF. F igure A . 2 shows an example o f p a r t i c l e s i z e ana lys i s o f s o i l used i n

drainage l ys ime te r D 0 1 - 0 2 . Figure A . 3 shows s o i l dens i t y da ta and c a l i bra-

t i o n curves f o r t h e Seaman Nuclear Probe.

WrT) N W W d O W N O a 3 6 W d m W N 0 N m r u m N N N V ) h N N N W Q ,

w a P,

P

m m u , 0

C3 m a

b N - 3 a 3 0 0 0 0 (U . . . . . m

Cr)W d h V ) d C r ) w m d m a d ~ C c ) + N O l + m m a a n -h

d h 03 N N N W a 3 N N d W 0 3 b W W C r ) h

4 n C3

w 0, n

O h 0 0 0 . . . a .

w o h h m N O C n b O N N C U W Q )

TABLE A.4. Fac tory C a l i b r a t i o n Values f o r Thermocoupl e Psychrometer

PSY FAC CAL 30R x 3C 0 8 - 0 8 - 8 7 9:26 Page 1

1 S e r i a l 2 Graph 3 Micro Number Scal e Vol t s

xr i m I

U I m m m m m m m m m m m m m m m m m m m m m + + t t t t U d d " " " d d d d " d " d d d d d m m m m m m

" , I . . . . . . . . . . . . . . . . . . . . . . . . . . . ~ ~ ~ ~ m m m m m m m m m m m m m m m m m m a 1 a m d ~ ~ d . - 1 4 0 0 1 d d d d d d d d d * r ( d d d d d d d d d d d d d d d d U > I N N N N N N N N N N N N N N N N N N N N N N N N N N N

I m I

W t N N N N N N N N N N N N N N N N N N N N t 4 d d d d d V - l LX I 0 I u * l l- I

!

I l Z Z Z Z I d N m t

+ . X I B B S Q L @ 1 **** v.- I + d d d

Y I B B B B x c I nnnn

Z Z Z m a d B d d I*** 4.4- B B B POP

Z Z Z Z ( R I P d N B d d d :**** t t t t B B B B nnnn

TABLE A . 5 . ( contd )

16 MOISTURE 17 MOISTURE 18 CR H20 19 CR H20 20 co118*.4966 COUNTS DAILY STND DAILY MEAN - .2146

,----------------------------------------------------------------

938.60 836 938.60 0.890 0.887 0.226 826 938.60 0.880 0.877 0.221 831 938.60 0.886 0.883 0.224 809 938.60 0.862 0.859 0.212 789 938.60 0.841 0.838 0.202 746 938.60 0.794 0.791 0.179 791 938.60 0.843 0.840 0.203 7 99 940.60 0.860 0.849 0.207 766 940.60 0.813 0.813 0.189 789 940.60 0.839 0.838 0.202 798 940.60 0.848 0.848 0.206 776 940.60 0.826 0.824 8.195 779 940.60 0.828 0.828 0.196 794 940.60 0.844 0.843 0.204 769 940.60 0.818 0.817 0.191

0 fix dry density ------------- 1 D01#0lN 2 D01#02N 3 D01#03N 4 D01#04N 6 D01#06N 6 D01#06N 7 D01#07N 8 DaitasN 9 D01#09N

10 D0l#l0N 11 D 0 l # l l N 12 D0l#l2N 13 D01#13N 14 D01#14N 16 D01#16N 16 D01#16N 17 D02#01N 18 D02#02N 19 D02#03N 20 D02#04N 21 D02#0SN 22 D02#06N 23 D02#07N 24 D02#08N 26 D02109N 26 D02#10N 27 D02#l lN 28 D02#12N 29 D02#13N 30 D02#14N 31 D02#16N 32 D02#16N 33 D03#0lN 34 D03#02N 36 D03#03N 36 D03104N 37 D0S#06N 38 D03#06N 39 D03#07N 40 D03#08N 41 D03#09N 42 D03#10N 43 D04#01N 44 D04#02N 46 D04#03N 46 D04#04N 47 D04)BSN 48 D04#06N 49 D04#07N 60 D04#08N 61 D04#09N 62 D04#10N 63 D04#11N 64 D04#12N

12 DENSITY 13 CR DEN 14 CR DEN DAILY STAND DAILY MEAN

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Documents

The Field Lysimeter Test Facility (FLTF) at the Hanford Site