Development Document for
Proposed Effluent Limitations Guidelines
and New Source Performance Standards
for the
WET STORAGE, SAWMILLS,
PARTICLEBOARD AND
INSULATION BOARD
Segment of the
TIMBER PRODUCTS
PROCESSING
Point Source Category
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
AUGUST 1974
-------
-------
EEVELQPMENT DOCUMENT
for
EFFLUENT IJMITATICNS GUIDELINES
and
NEW SOURCE PERFORMANCE STANDARDS
f or the
WET STORAGE, SAWYELLS, PARTICLEBCftRD
AND INSULATION BOARD
SEGMENT CF THE
TIMEER PRODUCTS PROCESSING
POINT SOURCE CATEGORY
Russell E. Train
Administrator
James L. Agee
Assistant Administrator for Vfeter and Hazardous Materials
Allen Cywin
Director, Effluent Guidelines Division
Richard E. Williams
Project Officer
August 1974
Effluent Guidelines Division
Office of Water Planning and Standards
United States Environmental Protection Agency
Washington, D.C. 20460
-------
-------
ABSTRACT
A study was made of the timber products processing point source
category for the purpose of developing information to assist the
Agency in establishing efflueat limitations guidelines and
standards to implement Sections 301, 304, 306, and 307 of the
Federal Water Pollution Control Act Amendments of 1972.
The portions of the industry studied included the insulation
board manufacturing, particleboard manufacturing, sawmills and
planing mills, wet storage, i.e., pond and wet deck storage of
unprocessed wood, and the operations of log washing, finishing,
fabrication, by-product utilization and dry deck storage.
The wet storage, sawmills, particleboard and insulation board
segment of the timber products processing industry is divided
into seven subcategories. The subcategorization was based on the
processing procedures involved and the water requirements, in
terms of both quantity and quality.
The subcategories, as presented in this document are: wet
storage, log washing, sawmills and planing mills, finishing,
particleboard manufacturing, insulation board manufacturing and
insulation board manufacturing with steaming or hardboard
production.
Best Practicable Control Technology Currently Available (BPCT),
Best Available Technology Economically Achievable (BAT), and New
Source Performance Standards (NSPS) for five subcategories in
this segment of the industry is defined as no discharge of
process waste waters pollutants to navigable waters. The
insulation board manufacturing portion of the segment has
quantitative limits on discharge. Limits on the wet storage
subcategory are basically no discharge of waste water pollutants
with an allowance for discharge volume related to precipitation-
evaporation considerations.
-------
-------
TABLE OF CONTENTS
SECTION PAGE
I CONCLUSIONS 1
II RECmSEJTOATIONS 3
III INTRODUCTION 9
Purpose and Authority 9
Basis for Guidelines and Standards 9
Development
Definition of the Tiitiber Products Industry 11
Background of the Tiittoer Products Industry 16
Inventory of the Timber Products Industry 19
Description of Processes 30
IV INDUSTRY CATBQORIZATICN 79
Surmary of Subcatergorization 85
V V&TER USE AND VffiSTE CHARACTERIZATION 87
Storage of Logs in Estuaries, Impoundments, 87
Rivers, and Transportation of Logs
in Vfeter
Mill Ponds 91
Log Ponds 102
Storage of Logs on Land {Wet Decking) 132
Storage of Logs on Land (Dry Decking) 138
Storage Piles of Fractionlized Wood 140
Log Washing 149
Sawmills 151
Fabrication 156
insulation Board 165
Particleboard 177
Finishing Operations 185
VT POLLUTANT PARAMETERS 193
-------
PAGE
VII CCNTROL AND TREATMENT TECHNOLOGY 209
Impoundments and Estuarine Storage and 209
Transportation
Wet Storage 209
Mill Ponds 209
Treatment Control 211
Log Ponds 223
Wet Decking 234
Dry Decking 238
Storage of Fractionalized Wood 239
Log Hashing 240
Sawmills 240
Fabrication 243
Insulation Board 261
Particleboard 288
Finishing 299
VIII COST, ENERGY, AND NCN-WATER QUALITY ASPECTS 303
Impoundments and Estuariiie Storage and 304
Transportation
Wet Storage 305
Mill Ponds 305
Log Ponds 320
Wet Decking 334
Log Washing 336
Savmills and Planing Mills 340
Finishing 341
Insulation Board Subcategories 354
Cost and Reduction of Alternative Treatment 355
and Control Technologies
Particleboard Subcategory 379
Finishing with Water Reducible Materials 390
IX BEST PRACTICABLE CONTROL TECHNOLOGY
CURRENTLY AVAILABLE 395
X BEST AVAILABLE TECHNOLOGY BXNCMtCALLY
ACHIEVABLE 407
XI NEW SOURCE PERFORMANCE STANDARDS 411
XII ACKNOWLEDGEMENTS 415
XIII REFERENCES 417
XIV GLOSSARY 427
VI
-------
NUMBER
FIGURES
PAGE
1 Interrelationships of the Timber Products 12
Industry
2 Production of Insulation Board 1949-1970 17
3 Particleboard Production 18
4 Sawmills and Planing Mills 22
5 Production of Softwoods and Hardwood 1967 23
6 Millwork Plants 27
7 Wood Container Manufacturers 28
8 Finished Panel Producing Plants 29
9 Wood Products Not Elsewhere Classified 32
10 Map of Insulation Board Plant Locations 33
11 Particleboard Manufacturing Facilities 35
12 Hydraulic Shotgun 46
13 Process Diagram of Rough Green Sawmills 50
14 Process Diagram of Band Sawmill 51
15 Process Diagram Multiple Headrig Sawmill 52
16 Standard Glue Joints 55
17 Process Diagram for Laminated Timber Manufacture 57
18 Insulation Board Process 59
19 Schematic Diagram of Cylinder Forming Machine 63
20 Particleboard Process Flow Diagram 66
21 Process Flow Diagram for the Manufacture of 75
Printed Grain—Pre-f inished Paneling
22 Process Flow Diagram for Vinyl Film Overlaying 78
23 log Pond 01 105
24 Log Pond 02 106
25 Log Pond 03 107
vn
-------
PAGE
26 Bottom Contours for Log Pond 01 117
27 Bottoti Contours for Log Pond 02 118
28 Bottom Contours for Log Pond 03 119
29 Tenperature, pH and Dissolved Oxygen Profiles 120
for Log Pond 01
30 Temperature, pH and Dissolved Oxygen Profiles 121
for Log Pond 01
31 Tenperature, pH and Dissolved Oxygen Profiles 122
for Log Pond 02
32 Tenperature, pH and Dissolved Oxygen Profiles 123
for Log Pond 02
33 Tenperature, pH and Dissolved Oxygen Profiles 124
for Log Pond 03
34 Tenperature, pH and Dissolved Oxygen Profiles 125
for Log Pond 03
35 Particle Size Analysis for Douglas Fir Bark 142
and Sawdust
36 Runoff Flow Rate Vs. Rainfall Intensity for 147
Whitewood and Redwood Chip Piles and a Sawdust
Pile
37 Water Balance for a Sawnill Producing 60,000 155
Cubic Meters Per Year
38 Typical Glue Tiines 159
39 Water Balance for a Typical Insulation Board 166
Process
40 Variation of BCD with Preheating Pressure 172
41 Variation of the Ratio of BCD/Dissolved Solids 173
with Yield
42 Waste Water Production in a Prefinished Panel 191
Plant
43 BCD -3 Variation with Dilution 205
44 Variation of BOD with Sarrple Concentration 206
45 Alternative Treatment Schemes for Mill Ponds 213
46 Alternative B for Mill Ponds 217
vm
-------
PAGE
47 Alternative D2 for Mill Ponds 219
48 Alternative E for Mill Ponds 222
49 Alternative F for Mill Ponds 224
50 Alternative Treatment Schemes for Log Ponds 226
51 Alternative B for Log Ponds 229
52 Alternative C for Log Ponds 230
53 Alternative D for Log Ponds 233
54 Alternative Treatment Schemes for Wet Decking 236
55 Log Wash Recycle System 241
56A Titration Curve for Hardwood Glue 245
56B Titration Curve for Phenolic and Protein Glue 246
57 COD and TOC of Supernatant Vs. pH for Protein 247
Glue
58 CCO of Supernatant Vs. pH for Phenolic Glue 248
59 Alternative B for Glue Waste Disposal 256
60 Alternatives C and D for Fabrication 259
61 Alternative E for Glue Washwater Reuse System 260
62 Water Recycle System Type I for Insulation 263
Board
63 Water Recycle System Type II for Insulation 264
Board
64 Conpatability of Process Waters of Various 267
Products - Insulation Board
65 Schematic of Suspended Solids Removal for 269
Process White Water Recycle in Insulation Board
Plants
66 Water Reuse Possibilities for an Insulation 271
Board Plant
67 Variation in BOD and Suspended Solids from 275
Secondary Treatment in Plant No. 7
68 Variation in BCD and Suspended Solids from 276
Secondary Treatment Effluent in Plant No. 9
-------
PAGE
69 Variation in BCD and Suspended Solids from 277
Secondary Treatment in Plant No. 12
70 Variation in BOD and Suspended Solids from 278
Secondary Treatment in Plant No. 14
71 Variation in BCD and Suspended Solids from 279
Secondary Treatment in Plant No. 16
72 Schematic of Alternative B for Insulation 282
Board
73 Schematic of Alternatives Cl and Dl for 284
Insulation Board
74 Schematic of Alternative C2 for Insulation 285
Board
75 Schematic of Alternative D2 for Insulation 285
Board
76 Schematic of Alternative E for Insulation 287
Board
77 Schematic of Alternative F for Insulation 289
Board
78 Schematics of Alternatives B, C, and D for 296
Particleboard
79 Schematics of Alternatives E and F for 298
Particleboard
80 Total Investment Cost and Total Yearly Cost 310
Vs. COD Reduction for Alternative C
81 Total Investment Cost and Total Yearly Cost 312
Vs. CCD Reduction for Alternative D
82 Total Investment Cost and Total Yearly Cost 316
Vs. CCO Reduction for Alternative E
83 Total Investment Cost and Total Yearly Cost 324
Vs. COD Reduction for Alternative B
84 Total Investment Cost and Total Yearly Cost 327
Vs. CCD Reduction for Alternative C
85 Total Investment Cost and Total Yearly Cost 331
Vs. CCD Reduction for Alternative D
86 Total Investment Cost and Total Yearly Cost 363
Vs. BCD Reduction for Alternative C -
Subcategory of the Insulation Board Industry
-------
PAGE
87 Total Investment Cost and Total Yearly Cost .-364'
Vs. BOD Reduction for Alternative C -
Subcategory II of the Insulation Board Industry
88 Total Investment Cost and Tota Yearly Cost 365
Vs. BCD Reduction for Alternative C -
Subcategory III of the Insulation Board Industry
89 . Total Investment Cost and Total Yearly Cost 367
Vs. BCD Reduction for Alternative D -
Subcategory I of the Insulation Board Industry
90 Total Investment Cost and Total Yearly Cost 368
Vs. BOD Reduction for Alternative D -
Subcategory II of the Insulation Board Industry
91 Total Investment Cost and Total Yearly Cost 369
Vs. BCD Reduction for Alternative D -
Subcategory III of the Insulation Board Industry
-------
-------
TABLES
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
PAGE
Property Requirements of Mat Formed Particleboard 15
Area and Volume Statistics by Ownership 20
Classes, 1970
Lumber Production by Regions - 1971 and 24
by Mill Size
Manufacturers of Prefabricated Structural Wood 26
Members and Wood Laminates
Types of Factory Finished Panels 31
Inventory of Insulation Board Plants 34
Particleboard Producing Plants by Geographic 35
Areas, 1973
U. S. Particleboard (Mat-Formed) 33
Producers
Wood Adheslves: Properties, Handling and Use Guide 54
BOD, COD, PBI and TOC in Inflow and Outflow 89
from Log Storage Reservoir Number 74
Log Pond Data 92
Winter Characteristics of Oregon Log Ponds 95
Part A: Chemical Characteristics
Literature Data for Ponds 98
Characterization of Mill Ponds 99
Data Correlations for Mill Ponds 101
Typical Waste Stream From a Mill Pond 103
Average Value and 95 Percent Confidence IQQ
Interval for Various Parameters for Log Pond 01
Average Value and 95 Percent Confidence 109
Interval for Various Parameters for Log Pond 02
Average Value and 95 Percent Confidence no
Interval for Various Parameters for Log Pond 03
Surface Sample Analyses for Log Pond 01 ill
xm
-------
PAGE
21 Surface Sample Analyses for Log Pond 02 112
22 Surface Sample Analyses for Log Pond 03 113
23 Winter Data for Log Ponds 01, 02, and 03 114
24 Diurnal Study on Log Ponds 01 and 02 115
25 Data from Log Ponds in the Washington, Oregon 116
Idaho Area
26 Data Correlations for Log Ponds 01, 02, and 03 127
27 Relationship of the Various Parameters to COD 128
for Log Ponds 01, 02, and 03
28 Typical Waste Streams from Log Ponds 131
29A Characteristics of Effluent from Wet Decking 134
Operations
29B Data Correlation for West Coast Wet Decking 135
30 Typical Waste Stream from Wet Decking Operations 137
31 Leachates from Dry Deck Experiment 139
32 Analysis of Cold Water Solubles in Bark, Wood, 141
and Moss Peat
33 Chip Pile Runoff Results 144
34 Chip Pile Runoff Summary 145
35 Bark Pile Effluent Character 148
36 "Typical" Effluent Stream from a Particle 148
Pile
37 Raw Waste Water Characterization Log Wash Water 150
38 Water Usage for an Actual Sawmill with Power 152
Plant and Log Storage
39 Makeup Requirements for Various Mixes 157
40 Glue Requirements for Various Mills 158
41 Volume of Waste Water Reported by Various 161
Mills
42 Characteristics of Glue Washwater (mg/1) 162
43 Average Chemical Analysis of Glue Waste Water 164
xiv
-------
PAGE
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
(Assuming A 40:1 Dilution with Water)
Total Plant Waste Water from Insulation Board
Effect of Hardwood, Steaming and Hardboard
Production on the BOD£ Load from Insulation
Board Plants
Particleboard Plant Process Water and Cooling
Water Flow Rates
Total Particleboard Plant Raw Waste Water
Discharge
Waste Water Analyses by Stream
Waste Water Generation from Finishing Plants
Chemical Analysis of Water Base Materials
Retardation of BOD Test Timber Products Effluents
(Leachates)
Efficiencies and Concentrations for the Various
Treatment Alternatives for Mill Ponds
Efficiencies and Concentrations for the Various
Treatment Alternatives for Log Ponds
Efficiencies and Concentrations for the Various
Treatment Alternatives for Wet Decking
Neutralization of Protein Glue Waste
Alum VS H2S04 for Neutralization of Phenolic
Glue Waste
Incineration Test for Phenolic, Protein
and Urea Glue
Volatile Solids in Phenol Resorcinol Waste Water
Potential Makeup Water Vs. Waste Water Production
Spray Evaporation Pond Design Alternative B
Existing Treatment Technology in the Insulation
Board Industry
Efficiency of Biological Treatment Processes
Summary of Effluents Produced by Treatment
Alternatives for Model Insulation Board Plants
Existing Particleboard Waste Water Treatment
Systems
170
174
178
183
184
187
189
207
214
227
237
249
250
252
253
255
257
272
273
290
293
xv
-------
PAGE
65 Itemized Cost Summary of Alternative B for 307
Mill Ponds
66 Itemized Cost Summary of Alternative C2 for 309
Mill Ponds
67 Itemized Cost Summary of Alternative D2 for 311
Mill Ponds Chemical Coagulation, Flocculation,
and Sedimentation Only
68 Itemized Cost Summary of Alternative E3 for 314
Mill Ponds F1Iteration and Sludge Disposal Only
69 Itemized Cost Summary of Alternative E4 for 315
Mill Ponds
70 Itemized Cost Summary of Alternative F for 318
Mill Ponds Evaporation Pond Only
71 Yearly Power Use and Costs of Alternative 319
Treatments for Mill Ponds
72 Itemized Cost Summary for Alternative Bl for 322
Log Ponds
73 Itemized Cost Summary for Alternative B2 for 323
Log Ponds
74 Itemized Cost Summary for Alternative C2 for 326
Log Ponds
75 Itemized Cost Summary for Alternative D3 for 328
Log Ponds
76 Itemized Cost Summary for Alternative D4 for 330
Log Ponds
77 Itemized Cost Summary for Alternative E for Log 332
Ponds
78 Yearly Power Use and Costs for Alternative 333
Treatment for Log Pond
79 Non-Mater Quality Wastes Generated for Land 335
Decking and Water Storage
80 Costs Summary for Wet Decking 337
81 Costs of Control and Treatment, Alternative B 339
for Log Washing Operations
82 Costs of Control and Treatment for Alternative 342
B for Fabrication Operations
xvi
-------
PAGE
83 Costs of Control and Treatment for Alternative 345
C for Fabrication Operations
84 Costs of Control and Treatment for Alternative 348
D for Fabrication Operations
85 Costs of Control and Treatment for Alternative 350
E for Fabrication Operations
86 Summary of Alternative Costs for Fabrication 353
Operations
87 Itemized Cost Summary for Alternative B for 356
Insulation Board
88 Itemized Cost Summary for Alternatives Cl, and 358
Dl for Insulation Board
89 Itemized Cost Summary for Alternative C2 for 360
Insulation Board
90 Itemized Cost Summary for Alternative B2 for 361
Insulation Board
91 Itemized Cost Summary for Alternative E for 370
Insulation Board
92 Itemized Cost Summary for Alternative F for 374
Insulation Board
93 Summary of Cost and Benefits of Treatment 375
Alternatives for the Model Insulation Board
Plant
94 Power Requirements of Treatment Alternatives -376
1n the Insulation Board Industry
95 Itemized Cost Summary for Alternative B for 380
Particleboard
96 Itemized Cost Summary for Alternative C for 382
Particleboard
97 Itemized Cost Summary for Alternative D for .383
Particleboard
98 Itemized Cost Summary for Alternative E for 334
Particleboard
99 Itemized Cost Summary for Alternative F for 386
Particleboard
100 Summarized Cost of Treatment Alternatives for 387
Particleboard Plants
xvii
-------
PAGE
101 Power Requirements of Treatment Alternatives 389
1n the Partlcleboard Industry
102 Summary of Alternative Costs for Finishing 393
with Water Reducible Materials
103 Anticipated Annual Energy Costs for Alternate 394
Control Technologies for Finishing with Water
Reducible Materials
104 Conversion T£ble 446
xvm
-------
SECTION I
CONCLUSIONS
For the purpose of developing Effluent Limitations Guidelines and
New Source Performance Standards, this segment of the timber
products processing industry has been divided into seven
subcategories as follows:
(1) wet storage; (2) log washing; (3) sawmills and planing mills;
(4) finishing; (5) particleboard; (6) insulation board
manufacturing; and (7) insulation board manufacturing with
steaming or hardboard production.
The main criterion for subcategorization was process variation.
Factors such as plant size, age, nature of raw materials were
considered and found not to be significant in the
subcategorization as presented.
Waste water pollutants of significance for this segment of the
timber products processing industry include: BOD, COD, phenols,
oil and grease, pH, temperature, dissolved solids, suspended
solids, color, phosphorus, and nitrogen.
In addition, in those operations employing preservatives or
finishing, the following pollutants may be present.
Copper
Chromium
Arsenic
Zinc
Fluoride
Ammonia
Mercury
It was determined that for the wet storage of logs (i.e., the
storage of wood raw material in self contained bodies of water;
pond storage, and the storage of wood material on land, where
water is sprayed on the wood), best practicable control
technology (BPCT) and best available technology (BAT) limits the
allowable volume of discharge to the volume of precipitation that
falls on the drainage area of the wet storage facility less the
natural evaporation that occurs during the months of May through
October. Discharge volume during the months November through
April is limited to a volume equal to the precipitation that
falls on the facility. New source performance standards (NSPS)
for wet decking is the same as BPCT and BAT. NSPS for pond
storage is no discharge of waste water pollutants to navigable
waters. For the log washing subcategory, sawmills subcategory,
the finishing subcategory, and the particleboard subcategory
BPCT, BAT and NSPS limitations are no discharge of water water
pollutants to navigable waters. BPCT and NSPS for the insulation
board manufacturing subcategories is based on the application of
biological treatment before discharge, BAT for the insulation
-------
board subcategories is based on recycling a portion of the
treated waste water into the process water system.
As part of the development program for effluent guidelines and
standards for the timber products processing industry, other
activities in the industry were investigated. These activities
were the transportation and storage of logs on rivers, estuaries,
and impoundments; the storage of fractionalized wood in piles;
dry decking of logs, and the storage of processed timber
products; and storm water runoff from storage yards. This
investigation resulted in the conclusion that management
techniques are available to reduce the impact on the water
environment from these operations. However, the amounts, type,
and quality of the information currently available is not
considered adequate to serve as a basis for proposing national
standards and limitations.
Because of the complexity of the Phase II timber products
processing industry, and the undefinable number of processing
operations, it is not possible to estimate the total industry
cost of achieving the BPCTCA and BATEA. However, it is felt that
the technology developed herein is practical and that the total
industry cost will not be excessive. In most cases, the costs of
achieving these proposed limitations can be incorporated into the
selling price.
-------
SECTION II
RECOMMENDATIONS
The recommended effluent limitations guidelines and standards are
based on (1) best practicable control technology currently avail-
able, (2) best available technology economically achievable, and
(3) performance standards for new sources. The effluent limita-
tions as set forth herein are developed in depth in the following
sections of this document.
RECOMMENDED EFFLUENT LIMITATIONS BASED ON BEST PRACTICABLE
CONTROL TECHNOLOGY CURRENTLY AVAILABLE
SUBCATEGORY
Wet Storage
EFFLUENT LIMITATIONS
A. No discharge of process waste water pollu-
tants between May 1 and October 31, except
a volume of water equal to the difference
between the mean precipitation for a given
month and 10% of the annual lake evapora-
tion.
B. No discharge of process waste water pollu-
tants between November 1 and April 30,
except a volume of water egual to the mean
precipitation that falls on the drainage
area of the wet storage facility.
C. When a discharge is allowed the following
limitations shall apply:
Daily
Maximum
30-Day
Average
(metric unj.ts)
Debris
pH
(english units)
Debris
pH
maximum diameter, cm
2.5U 2.54
Within the range 5.5 to 9.0
maximum diameter, in
1.0 1.0
Within the range 5.5 to 9.0
Log Washing
Sawmills and
planing mills
Finishing
No discharge of process waste water pollutants
to navigable waters
No discharge of process waste water pollutants
to navigable waters
No discharge of process waste water pollutants
to navigable waters
-------
Partic1eboard
Insulation
board
BODS
TSS
pH
Insulation board
manufacturing with
steaming or
hardboard production
BOD 5
TSS
pH
No discharge of process waste water pollutants
to navigable waters
Daily
Maximum
kg/kkg
(Ib/ton)
3.75
(7.50)
9.40
(18.80)
30-Day
Average
kg/kkg
(Ib/ton)
1.25
(2.50)
3.13
(6.25)
Within the range 6.0 to 9.0
Daily
Maximum
kg/kkg
(Ib/ton)
11.3
(22.60)
30-Day
Average
kg/kkg
(Ib/ton)
3.75
(7.50)
9.UO
(18.80)
3.13
(6.25)
Within the range 6.0 to 9.0
RECOMMENDED EFFLUENT LIMITATIONS BASED ON BEST AVAILABLE
TECHNOLOGY ECONOMICALLY ACHIEVABLE
SUBCATEGORY
Wet Storage
EFFLUENT LIMITATIONS
A. No discharge of process waste water pollu-
tants between May 1 and October 31, except
a volume of water equal to the difference
between the mean precipitation for a given
month and 10% of the annual lake evapora-
tion.
B. No discharge of process waste water pollu-
tants between November 1 and April 30,
except a volume of water equal to the mean
precipitation that falls on the drainage
area of the wet storage facility.
C, When a discharge is allowed the following
limitations shall apply:
Daily
Maximum
30-Day
Average
(metric units)
maximum diameter, cm
-------
Debris
PH
(english units)
Debris
pH
NO
to
NO
to
NO
to
NO
to
Log Washing
Sawmills and
planing mills
Finishing
Particleboard
Insulation
board
BODS
TSS
PH
Insulation board
manufacturing with
steaming or
hardboard production
\
BODS
TSS
PH
2.54 2.54
Within the range 5.5 to 9.0
maximum diameter, in
1.0 1.0
Within the range 5.5 to 9.0
discharge of process waste water pollutants
navigable waters
discharge of process waste water pollutants
navigable waters
discharge of process waste water pollutants
navigable waters
discharge of process waste water pollutants
navigable waters
Daily
Maximum
kg/kkg
(Ib/ton)
1.13
(2.25)
2.85
(5.70)
30-Day
Average
kg/kkg
(Ib/ton)
0.38
(0.75)
0.85
(1-90)
Within the range 6.0 to 9.0
Daily
Maximum
kg/kkg
(Ib/ton)
3.38
(6.75)
30-Day
Average
kg/kkg
(Ib/ton)
1.13
(2.35)
2.85
(5.70)
0.85
(1.90)
Within the range 6.0 to 9.0
SUBCATEGORY
Wet Storage
RECOMMENDED NEW SOURCE
PERFORMANCE STANDARDS
A.
EFFLUENT LIMITATIONS
Subject to the provisions of paragraphs
B and C, which are applicable only to
-------
wet decking operations, there shall be no
discharge of process waste water pollu-
tants to navigable waters.
B. No discharge of waste water pollutants
between May 1, and October 31, except
a volume of water equal to the differ-
ence between the mean precipitation for
a given month and 10% of the annual lake
evaporation.
C. No discharge of waste water pollutants
between November 1 and April 30, except
a volume of water equal to the mean pre-
cipitation that falls within the drainage
area of the wet storage facility.
D. When a discharge is allowed the following
limitations shall apply:
Daily
Maximum
30-Day
Average
(metric units)
Debris
pH
(english units)
Debris
pH
maximum diameter, cm
Log Washing
Sawmills and
planing mills
Finishing
Particleboard
Insulation
board
BODS
TSS
NO
to
No
to
NO
to
No
to
2.54 2.5U
Within the range 5.5 to 9.0
maximum diameter, in
1.0 1.0
Within the range 5.5 to 9.0
discharge of process waste water pollutants
navigable waters
discharge of process waste water pollutants
navigable waters
discharge of process waste water pollutants
navigable waters
discharge of process waste water pollutants
navigable waters
Daily
Maximum
kg/kkg
(Ib/ton)
3.75
(7.50)
9.40
(18.80)
30-Day
Average
kg/kkg
(Ib/ton)
1.25
(2.50)
3.13
(6.25)
-------
pH Within the range 6.0 to 9.0
Insulation board Daily 30-Day
manufacturing with Maximum Average
steaming or kg/kkg kg/kkg
hardboard production (Ib/ton) (Ib/ton)
BODS 11.3 3.75
(22.60) (7.50)
TSS 9.40 3.13
(18.80) (6.25)
pH Within the range 6.0 to 9.0
-------
-------
SECTION III
INTRODUCTION
PURPOSE AND AUTHORITY
Section 301 (b) of the Federal Water Pollution Control Act, as
amended, hereinafter cited as "The Act," requires the achievement
be not later than July 1, 1977, of effluent limitations for point
sources, other than publicly owned treatment works, which are
based on the application of the best practicable control
technology currently available as defined by the Administrator
pursuant to Section 304(b) of the Act. Section 301 (b) also
requires the achievement be not later than July 1, 1983, of
effluent limitations for point sources, other than publicly owned
treatment works, which are based on the application of the best
available technology economically achievable which will result in
reasonable further progress towards the national goal of
eliminating the discharge of all pollutants, and which reflect
the greatest degree of effluent reduction which the Administrator
determines to be achievable through the application of the best
available demonstrated control technology, and processes,
operating methods, or other alternatives, including where
practicable, a standard permitting no discharge of pollutants.
Section 304 (b) of the Act requires the Administrator to publish
regulations providing guidelines for effluent limitations setting
forth the degree of effluent reduction attainable through the
application of the best practicable control technology currently
available and the degree of effluent reduction practices achiev-
able including treatment techniques, process and procedure
innovations, operation methods, and other alternatives. The
regulations proposed herein set forth effluent limitation
guidelines pursuant to Section 304(b) of the Act for selected
segments of the timber products processing category.
Section 306 of the Act requires the Administrator, after a
category of sources is included in a list published pursuant to
Section 306(b)(1)(A) of the Act, to propose regulations
establishing Federal standards of performances for new sources
within such categories. The Administrator published in the
Federal Register of January 16, 1973, (38 F.R. 1624), a list of
27 source categories. Publication of the list constituted
announcement of the Administrator's intention of establishing,
under Section 306, standards of performance applicable to new
sources with in the timber products processing category of
sources.
BASIS FOR GUIDELINES AND STANDARDS DEVELOPMENT ,
The effluent limitations and standards of performance recommended
in this document were developed in the following manner:
-------
1. An exhaustive review of available literature was
conducted. This included researches at the University of
Florida, University of California, Stanford University,
Oregon State University, University of Washington, and
University of North Carolina. Additional literature searches
were conducted at the United Nations Library in New York,
N.Y. and the Forest Products Laboratory in Madison,
Wisconsin.
2. Questionnaires were submitted to individual particleboard
and insulation board plants by the National Particleboard
Association and The Acoustical and Insulating Materials
Association, respectively. Seventy particleboard plants
responded, twenty five particleboard responses were usable,
and this information was incorporated into the data base.
Samples of the questionnaires are shown in Appendix A.
3. On-site inspections and sampling programs were conducted
at numerous installations throughout the U. S. Information
obtained included process diagrams, water usage, water
management practices, waste water characteristics, and
control and treatment practices information.
U. Other sources of information included: personal and
telephone interviews; meetings with industry advisory
committees, consultants, and EPA personnel; State and Federal
permit applications; and internal data supplied by the
industry.
The reviews, analyses, and evaluations were coordinated and
applied to the following:
1. An identification of pertinent features that could
potentially provide a basis for subcategorization of the
industry. These features included the nature of raw
materials utilized, plant size and age, the nature of
processes, and others as discussed in Section IV of this re-
port.
2. A determination of the water usage and waste water
characterization for each subcategory, as discussed in
Section V, including the volume of water used, the sources of
pollutants, and the types and quantities of constituents in
the waste waters.
3. An identification of the waste water constituents, as
discussed in Section VI, which are characteristic and which
were determined to be pollutants subject to effluent
limitation guidelines and standards.
4. An identification of the control and treatment
technologies presently employed or capable of being employed
by the industry, as discussed in Section VII, including the
effluent level obtainable and treatment efficiency and
reliability associated with each technology.
10
-------
5. An evaluation of the cost, energy, and non-water quality
aspects associated with the application of each control and
treatment technology as discussed in Section VIII.
DEFINITION OF THE TIMBER PRODUCTS INDUSTRY
The timber products industry is defined in this study as that
listed in Standard Industrial Classification (SIC) Major Group
24. The major portions included in SIC 24 are:
1. Logging camps and logging contractors; 2. Sawmills and
planing mills; 3. Millwork, veneer, plywood and structural
wood members; 4. Wood containers; 5. Wood buildings and
mobile homes; and 6. Miscellaneous wood products.
Segregated under the various major topics in Major Group 24 are
hundreds of industrial operations with products ranging from
finished lumber, hardboard, and mobile homes to tobacco hogshead
stock, chicken coops, and toothpicks. The magnitude and
complexities of operations range from backyard wood carving, to
complexes covering 1000 acres or more.
Also, rather than each operation being a discrete function within
the industrial segment, the timber products processing industry
is an interrelated one. As illustrated in Figure 1, the waste
material from one operation is often a raw material for another.
An example of this is in the production of particleboard where
sawdust, planer shavings, veneer cores, plywood scraps, and other
waste wood materials commonly serve as raw materials.
Earlier, effluent guidelines and standards were developed for the
barking, veneer, plywood, hardboard, and wood preserving segment
of the timber products processing industry. These operations
were considered to be the most significant sources of water
pollution problems. Guidelines and standards for that segment of
the industry were promulgated on April 18, 1974 (F.R. 39, 13942).
In order to achieve an orderly, logical, and practical approach
to the development of effluent guidelines, the remaining portions
of the industry have been considered in three broad areas: (1)
raw material and waste product storage and handling, (2)
sawmills, and planing mills, and various unit operations, and (3)
the production of insulation board and particleboard. The first
area includes such operations as timber transport and storage;
storage piles of fractionalized wood; and runoff from roofs,
yards, and other sources. Timber harvesting may be further
defined as all operations concerned with the cutting and trimming
of trees in the forest. Timber transport involves the moving of
logs from the harvest area by means of water, rail, or truck to a
processing plant. Log storage includes both storage in water and
on land, whether at a processing plant site or at other areas.
Storm runoff is defined as all water produced by precipitation
falling on the roof of a facility or on the adjacent grounds.
Storm runoff is considered to be separate from process waters and
11
-------
FrtUFST TRANSPOR- LOG SORTING
rUHtol ir\**n^rwn AND STORAGE
RESOURCES -TAT10N fl p%v pr^K •)
(HARVESTED TIMER) TRUCK D. WET DECK
(HARVESTED TIMER) RA]|_ QR C.WATER STORAGE
BARK REMOVAL
a. HYDRAULIC
K>D , ,
[
* • PLANING MILLS
PLYWOOD CHIP. AND
SAWDUST 1 '
i 4 PLANEft j
\ ^ SHAVIHfS
44-
HARDBOARD IMSULATIO
O.WETPROCESS ^^
b. DRY PROCESS BOARD
- T ,.
1 F P
PLYWOOD ^
•i b •EXTRUDED
w
Jf
FINISHING AND
MISCELLANEOUS
OPERATIONS
i
N 4—^
t. LUMICK
FIGURE 1 INTERRELATIONSHIPS OF THE TIMBER PRODUCTS INDUSTRY
12
-------
does not include runoff originating in storage piles of logs or
fractionalized wood.
In the second study area sawmills and planing mills are
considered to be those installations producing lumber and similar
products from logs. Other unit processes include log washing,
fabricating, finishing, machining and by-product utilization.
These operations may occur either singularly or in combination
with one another or with other processes. Log washing removes
grit from logs by washing the logs with water. Fabricating
includes those operations using adhesives to join various wood
members. Finishing, such as sanding, varnishing or painting,
concludes the final processing activates. Machining shapes wood
or wood products to a desired form by splitting, turning,
carving, drilling, sawing, grooving, and cutting. By-product
utilization converts bark, sawdust, and other scrap material into
wood flour, pressed logs, mulch, ornamental bark, or molded wood.
This does not include, however, the production of insulation
board or particleboard.
Insulation board is a form of fiberboard, which in turn is a
broad generic term applied to sheet materials constructed from
ligno-cellulosic fibers. It can perhaps best be classified on
the basis of density, and most broadly as "compressed" and
"noncompressed." Compressed fiberboards (hardboards) have a
density over 0.5 g/cu cm (31 Ib/cu ft) and noncompressed
fiberboards (insulation boards) have a density of less than 0.5
g/cu cm (31 Ib/cu ft). Insulation boards are usually
manufactured in thicknesses between 5 and 25 mm (3/8 and 1 in).
On a basis of density, insulation board may be subdivided into
semi-rigid insulation board and rigid insulation board with
densities of 0.15 g/cu cm (9.5 Ib/cu ft) and 0.15 to 0.40 g/cu cm
(9.5 to 25 lb/ cu ft), respectively. Semi-rigid insulation board
is normally used only for insulation purposes while rigid
insulation board may be used for sheathing, interior panelling,
and as a base for plaster or siding.
There are seven basic types of insulation board products as cited
by the Acoustical and Insulating Materials Association. The
principal types include:
1• Building board - General purpose product for interior
construction.
2- Insulating roof deck - A three-in-one component which
provides roof deck, insulation, and finished inside
ceiling. (Insulation board sheets are laminated
together with waterproof adhesives).
3. Roof insulation - Insulation board designed for flat
roof decks.
**• Ceiling tile - Insulation board embossed and decorated
for interior use. It also provides acoustical
qualities.
13
-------
5. Lay-in-panels - A tile used for suspended ceilings.
6. Sheathings - Board used extensively in construction
because of its insulative, bracing strength, and noise
control qualities.
7. Sound deadening insulation board - A product designed
specifically for use in buildings to control noise
level.
The American Society for Testing and Materials sets standard
specifications for the above categories and others.
Particleboards are board products which differ from conventional
fiber boards in that they are composed of distinct particles of
wood or other ligno-cellulosic materials which are bonded
together with an organic binder. The "particles" vary is size
and must be distinguished from the fibers used in insulation and
hardboard. Other terms used for particle board include
chipboard, flakeboard, silverboard, shaving board, and wood waste
board. Particleboard is a highly engineered product which can be
formed to meet varied specifications. As a result of its being
produced in wide density ranges, it is usually divided into
categories of low density (0.25 to 0.40 g/cu cm) (15 to 25 Ib/cu
ft), medium density (0.40 to 0.80 g/cu cm) (25 to 50 Ib/cu ft),
and high density (0.80 to 1.20 g/cu cm) (50 to 75 Ib/cu ft).
Low density particleboards are for use either as panel material,
where heat or sound insulation is important, or as a core in
veneered constructions where weight savings are important. The
major use for low density particleboard is as the core in wood or
plastic flush doors. These boards are usually manufactured in
thicknesses of no greater than 2.5 cm (1 in).
Most of the particleboard currently produced can be classified as
medium density board having a density some 10 to 20 percent
higher than that of the species of wood or material used. The
mat-formed board may be homogeneous throughout its thickness with
respect to the particles used; or it may be composed of two or
more discreet layers; or it may be graduated from face to core
with respect to particle size. Extruded particlebaord, however,
must use the same type of particle throughout its thickness
because of the nature of its production.
High density particleboard is quite similar to hardboard in
density, appearance, and application, the basic difference being
one of bond. It is usually produced in the same thicknesses as
conventional hardboard, and the small sized particles which are
used may approach wood fiber in size.
The U. S. Department of Commerce sets forth a Commercial standard
for manufacture of mat-formed wood particleboard, which covers
both interior and exterior applications and includes such
property requirements as density, modulus of elasticity, modulus
14
-------
TABLE 1.
PROPERTY REQUIREMENTS OF MAT FORMED PARTICLEBQARD
Density
(Grade)
Type (min. avg.)
1
1
1
2
2
A
(High Density
0.80 gm/cm3
and over)
B
(Medium Density
between 0.40
and 0.80 gm/cm3)
C
(Low Density
0.40 gm/cm3 and
under)
A
(High Density
0.80 gm/cm3
and over
B
Class
1
2
1
2
1
2
1
2
1
Modulus of
Rupture
(min. avg.)
ATM
164
232
110
164
55
96
164
232
124
Modulus of
Elasticity
(min. avg.)
ATM
23,820
23,820
17,010
27,220
10,210
17,010
23,820
34,030
17,010
Internal
Bond
(min. avg.) ,
ATM
15
11
6
5
2
3
10
28
5
Linear
Expansion
(max. avg.)
percent
0.55
0.55
0.35
0.30
0.30
0.30
0.55
0.55
0.35
Screw Holding
Face
(min.
__Kfl_
204
-
102
120
57
80
204
-
227
102
Edge
avg.)
Kg
-
-
73
91
_
-
_
159
73
(Medium Density
less than 0.80
gm/cm3)
171
30,620
0.25
114
91
Type 1 - Mat formed particleboard (generally made with urea-formaldehyde resin binders) suitable interior
applications.
Type 2 - Mat-formed particleboard made with durable and highly moisture and heat resistant binders (generally
phenolic resins) suitable for interior and certain exterior applications.
-------
of rupture, internal bond, screw holding, and linear expansion
(Table 1) .
BACKGROUND OF THE TIMBER PRODUCTS INDUSTRY
Forests have from the beginning been one of North America's more
important natural resources. The earliest sawmills and lumbering
operations date back to 17th century New England. The apparently
inexhaustable supply of virgin timber met the needs of a
developing country as the lumbering frontier spread to the Middle
Atlantic and Lake States and onward to the South and the Pacific
Northwest. By the early 20th century the industry was well
established throughout the country and continuing development of
equipment and techniques increased productivity. There are
currently in the United States over 200 million commercial ha
(500 million ac) of forest and over 40,000 establishments in the
timber products processing industry.
In recent years, the U. S. has become an increasingly important
exporter of wood products. However, since the U. S. has the
world * s highest per capita consumption of forest products,
imports usually double exports, with Canada being the largest
supplier. Pressing housing needs for domestic and foreign
markets have created shortages in lumber supply and have raised
questions concerning export control. Nevertheless, foreign trade
affords increased incentives for production.
The economics of the timber products industry is increasingly
affected by growth as well as changes in product demand. Over
the past half century an awareness of the losses in timber supply
associated with processing has developed and from this has
stemmed an extensive waste utilization program, i.e., the use of
chips, shavings, sawdust, and other scraps in the production of
various wood based products. Insulation board alone is produced
in ten types, each meeting specific needs of the market and
creating new demands. Since 1956, according to the U. S.
Department of Agriculture, 64 percent of the growth in the
insulation board industry has been in new plants as opposed to
expansion of existing facilities. Within the last decade, the
industry has more than doubled its capacity, as shown in Figure
2. The increased capacity has been accompanied by a decrease in
use of non-wood fibers in production as indicated by a 4.8
percent increase per year in raw wood materials consumed for the
period 1956 to 196a.
One of the newest additions to the industry, particleboard, has
experienced an eight-fold growth in production since 1956 (Figure
3) because of its versatility. The industry has also expanded
into the production of prefinished panels, wood containers,
prefabricated buildings, and specialty products. In 1958, the
production of particleboard was over 1.16 million sq m (125
million sq ft) on a 1.91 cm (0.75 in) basis) (5). Production
rates has tripled this figure by 1962, and in 1972 the Bureau of
Census reported a production peak of over 300 million sq m (three
16
-------
l,500n
O
O
c
o
H
O
O
o
o
s
rn
H
2)
o
•H
O
1,000-
500-
1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 I960 1961 1962 1963 1964 1965 1966 1967 1968 1969 197C
YE A R
FIGURE 2 PRODUCTION OP INSULATION BOARD, 1949-1970
-------
to
<
to
300,000-1
o
o
O 200,000
00
I-
o
3
a
o
tt 100,000
a.
1959
-1 1
1980 I9«l
-1 1
1962 1963
—I 1
1964 1965
1966
—I 1
I96T 1966
1969
—I—
1970
—1—
1971
I9T2
FIGURE 3 PARTICLEBOARD PRODUCTION
-------
billion sq ft) on a 1.9 cm (0.75 in) basis from 71 plants. This
is illustrated in Figure 2.
A study by the U. S. Department of Agriculture on industry trends
of particleboard during the period 1956 to 1966, reported only 25
particleboard plants in the U.S. in 1956. The current number of
approximately 76 particleboard plants indicates a growth rate of
200 percent in the 17 year period. During the period from 1956
to 1966 three-fourths of increased particleboard capacity was
contributed to new mills which had the greatest development in
the South and West. Prior to 1961, production output was between
48 and 63 percent of designed plant capacity; but since 1961, the
percentage has increased to 70 percent capacity, except in the
North where output is about 50 percent of capacity.
INVENTORY OF THE TIMBER PRODUCTS INDUSTRY
The U. S. possesses 200 million ha (0.5 billion ac) of commercial
forest land with a total inventory of 6 billion cu m (2,400
billion bd ft). This land is owned by four groups as indicated
in Table 2.
The major single user of forest resources is the pulp and paper
industry which produces about 47 billion metric tons (52 billion
tons) of pulp per year and requires approximately 50 million
cords of wood. This corresponds to approximately 126 million cu
m (4.5 billion cu ft) of timber per year. In 1968, the plywood
industry produced about 1.4 billion sq m (15 billion sq ft) of
9.53 mm (3/8 in) softwood plywood and 0.198 billion sq m (2.13
billion sq ft) of 6.35 mm (0.25 in) hardwood plywood. This
corresponds to approximately 30 million cu m (1 billion cu ft) of
timber in 1968. In 1973, the total volume of timber utilized by
the plywood industry was about 56 million cu m (2 billion cu ft).
The production of hardwood plywood requires an additional 28
million cu m (1 billion cu ft) of timber. The total timber
production in 1972 was about 88 thousand cu m (38 million bd ft).
This corresponds to about 112 million cu m (4 billion cu ft) of
timber per year. The sum of these uses 322 million cu m (11.5
billion cu ft) compared with the reported total timber removal .of
392 million cu m (14 billion cu ft) in 1970.
Following harvesting, timber must be transported to and stored in
various stages to processing plants. The storage and
transporation of logs in water is practiced extensively in the
northwestern U. S. and in Alaska. In 1964, approximately 9,000
ha (23,000 ac) of water were used to store and transport logs in
the Northwest. This was comprised of about 6,000 ha (14,000 ac)
in Oregon, 2,000, ha (4,000 ac) in Washington, 2,000 ha (4,000
ac) in California, and 400 ha (1,000 ac) in Idaho. It is
estimated that as of 1971 Alaska used about 400 ha (1,000 ac) of
its waterways for logs storage and transportation. Logs are
transported almost exclusively by water in Alaska.
In contrast, virtually all raw material transport in the South
and East is by truck or by rail, where logs may be hauled either
19
-------
TABLE 2
AREA AND VOLUME STATISTICS BY OWNERSHIP CLASSES, 1970
to
o
Ownership Classes
National Forests
Other Public
Forest Industry
Other Private
National Total
Commercial
Area Held
(Million
Hectares }
37.2
17.9
27.3
119.9
202.3
In Million Cubic Meters
Total Softwood Sawtimber Volume
Inventory
2,291
520
742
891
4,444
Growth
20
9
23
41
93
Removal s
30
10
38
33
111
Total Hardwood Sawtimber Volume
Inventory
91
93
159
859
1,202
Growth
3
4
6
33
46
Removal s
1
1
4
28
34
-------
in tree length, logs in cord pile lengths, or in a chipped form.
No water storage of logs is practiced in the southern U. S.
primarily because southern pine tends to sink. In a study of
land decking by the Southern Forest Products Association, W8
plants responded to questionnaires out of a total of 79 that were
sent. Of the companies responding, 21 companies used spray on
the land decks and 27 did not. The only case of water
transportation of logs observed in the South involved logs being
harvested from an island in the Mississippi River. In this
special case, it was easier to barge the logs down the river to
the mill site than to barge them to the adjacent bank of the
river for transfer to truck or rail.
The most complete available inventory of sawmills is contained in
"the 1973 Directory of Forest Products Industry. This reference
should be consulted for information on individual mills. In
order to present a general perspective on the magnitude and
distribution of sawmills in the U.S. Figures 4 and 5
respectively, indicate the number of sawmills in 1967 by state
and region, and a breakdown of production in millions of bd ft on
a state, regional, and national basis as well as by major type
shown, i.e., hardwood or softwood. The total number of sawmills
and planing mills in 1967 was 10,271. It should be noted that
the figures presented in Table 3 are for general sawmills and
planing mills. These are defined by the Bureau of Census as
those establishments primarily engaged in sawing rough lumber and
timber, from logs and bolts; resawing cants and flitches into
lumber, including box lumber and softwood cutstock; planing mills
combined with sawmills; and separately operated planing mills.
Thus, the segment of the industry which produces hardwood
dimension, flooring, and special product sawmills (totaling 1,190
establishments in 1967) is not included. Also not included are
mills producing prefinished panels, millwork, wood containers,
prefabricated wood products, and other miscellaneous wood
products. These will be covered in other sections of this
document.
Table 3, from Forest Industries, Volume 99 indicates the range of
mill sizes. The information presented is a result of a survey of
mills responsible for approximately 65.2 percent of the total
1971 production in the U. S.. It should be noted that a
relatively small number of mills represent an extremely large
percentage of production. Thus, in the western region, 257
mills, less than three percent of the total, accounted for nearly
37 percent of the total production in the U.S. The top twenty-
five companies in the U. S. accounted for approximately 30
percent of the total production of the country in 1971.
Those unit operations encountered at sawmills which may result in
significant waste water problems include storage, washing, and
debarking (Barking standards were promulgated earlier (40 CFR
Part 429, Subpart A)) of logs. The following discussion of log
washing is presented in order that an indication may be provided
of its present magnitude and frequency of occurrence as well as
possible future trends in the industry.
21
-------
NJ
M
FIGURE 4 SAWMILLS AND PLANING MILLS
-------
ALASKA AND HAWAII
SOFT - 460
HARD - 0
TOTAL- 460
MOUNTAIN PIVISIOM
SOFT - 9627
HARD • 40
TOTAL-9667
NORTH-WEST CENTRAL DIVISION
SOFT - 489
HARD - 980
TOTAL- 1359
NORTH-EAST CENTRAL_ DIVISION,
SOFT • 306
HARD - 2445
TOTAL - 2731
NEW EN8LAMD DIVISION
SOFT - 1062
HARD - 413
TOTAL- 1475
10
CO
MIDDLE ATLANTIC DIVISION
SOFT - 373
HARD • I68S
SOFTWOOD - 65040
HARDWOOD- 17269
U.S.TOTAL- 82309
PACIFIC DIVISION
SOFT-37695
HARD - 42O
(S) - DID NOT MEET
CONSISTENCY STANDARDS,
SOUTH ATLANTIC DIVISION
SOFT - 6986
HARD - S I I 5
SOUTH-EAST CENTRAL DIVISION
SOFT -3708
HARD-3934
SOUTH-_WEST CENTRAL DIVISION
SOFT -4844
HARD -2 268
UMTS SHOWN ARE IN
THOUSAND CUBIC METERS.
TOTAL-7 I I 2
TOTAL-1 2 I 0 I
FIGURE 5 PRODUCTION OF SOFTWOODS AND HARDWOODS 1967
-------
TABtE 3
TITMRKR PRODUCTION BY REGIONS - 1971 AND BY MILL SIZE*
West
South
North and East
Production Range
(Thousand Cubic Meters)
120 - up
60 - 120
23 - 60
12 - 23
7 - 12
Other
Total s
120 - up
60 - 120
23 - 60
12 - 23
7 - 12
Other
Total s
120 - up
60 - 120
23 - 60
12 - 23
7 - 12
Other
Number
Companl es
87
55
96
36
16
83
373
19
16
63
83
58
364
-
4
17
32
50
162
Number
Mills
257
59
106
40
16
84
562
71
25 .
68
88
58
439
-
7
32
39
52
162
Production
(Meters)
33,038,519
4,567,041
3,613,833
576,399
132,514
166,189
42,094,495
5,847,699
1,246,298
2,120,136
1,309,708
491,542
11,354,608
__
306,152
640,873
470,201
415,362
477,557
*The above production represents approximately 65.2 percent of total U.S.
production for 1971.
24
-------
Log washing is one of several unit operations which may or may
not be associated with a particular sawmill. While numerical
inventory of those plant practicing log washing is not available,
it can be stated that the majority of sawmills do not practice
log washing. A survey of southern pine mills by one industry
association showed that approximately twelve percent of the mills
returning questionnaires utilized log washing. Plant visits and
information developed during the current guidelines development
program determined that of the several dozen mills observed
throughout the southeast. Northwest, and Northeast, only a few
were found to have log washing operations.
The millwork industry comprises establishments primarily engaged
in manufacturing fabricated millwork, either prefinished or
unfinished. The number of mills and their distribution in 1967
is presented in Figure 6. It should be noted that the values for
number of mills include planing mills only if such mills are
primarily engaged in millwork production. For information
regarding specific companies or mills, reference should be made
to Sweats Catalogue or any other such manufacturer's guide.
Inventories are also available through the associations listed in
Appendix B.
In 1967 the total number of establishments involved in the
production of prefabricated structural wood members and wood
laminates was 43. While no current complete inventory is
available, it can be assumed that the magnitude of the industry
has not varied significantly since 1967. The American Institute
of Timber Construction has provided the inventory of its member
companies presented in Table 4. This inventory includes the
ma jority of the industry both in number of plants and in
production.
The wood container segment of the timber products industry
includes establishments manufacturing nailed wooden boxes,
wirebound boxes and crates, veneer and plywood containers, and
cooperage. Figure 7 gives the total number of such
establishments and their distribution by region and state for
1967.
Because of changes in the Standard Industrial Classification
(SIC) Codes, an accurate inventory of establishments involved in
the manufacturing of wood buildings and mobile homes is not
available. There were, however, about 500 establishments
operated by over 330 firms engaged in the manufacture of mobile
homes. The total production of mobile homes in the U. S. in
1972 was approximately 567,000 units according to the Mobile
Homes Manufacturers1 Association.
Another important product of the timber products industry are
prefinished panels. A wide variety of factory finishing
operations are performed, to some degree, on most all types of
flat-stock, wood panels including hardwood and softwood plywood,
hardboard, and particle board panels. Figure 8 shows the
distribution of panel producing plants in the U.S. which, as
25
-------
TABLE 4
MANUFACTURERS OF PREFABRICATED STRUCTURAL WOOD MEMBERS AND WXD LAMINATES
Able Fabricators, Inc.
Spokane, Washington
Anthony Forest Products Co.
El Dorado, Arkansas
Architectural Wood Products, Inc.
Fresno, California
Bohemia Wood Systems
Eugene, Oregon
Boise Cascade Corporation
Boise, Idaho
Ronald A. Coco, Inc.
Baton Rouge, Louisiana
Duco-Lam, Inc.
Drain, Oregon
El Dorado Laminated Beams, Inc.
El Dorado Springs, Missouri
The Intermountain Company
Salmon, Idaho
Koppers Company, Inc.
Pittsburgh, Pennsylvania
Plant Locations:
Magnolia, Arkansas
Morrisville, North Carolina
Sumner, Washington
Laminated Timbers, Inc.
London, Kentucky
Laminated Wood Products Co.
Ontario, Oregon
Mid-West Lumber Company
Lincoln, Nebraska
Riddle Laminators
Riddle, Oregon
Rosboro Lumber Company
Springfield, Oregon
Standard Structures, Inc.
Santa Rosa, California
Structural Wood Systems, Inc.
Greenville, Alabama
Timberweld Manufacturing
Billings, Montana
Timfab, Incorporated
Clackamas, Oregon
Unadilla Laminated Products
Unadilla, New York
Weyerhaeuser Company
Tacoma, Washington
Plant Locations:
Albert Lea, Minnesota
Cottage Grove, Oregon
Wood Fabricators, Inc.
North Bill erica, Massachusetts
Woodlam, Incorporated
Tacoma, Washington
26
-------
NJ
FIGURE 6 MILLWORK PLANTS
-------
ISJ
CO
FIGURE 7 WOOD CONTAINER MANUFACTURERS
-------
to
O SOFTWOOD PLYWOOD PANELS
HARDWOOD PLYWOOD PANELS
HARDBOARD PANELS
PARTICLEBDARD PANELS
FIGURE 8 FINISHED PANEL PRODUCING PLANTS
-------
reported by the 1973 Directory of the Forest Products Industry,
produce one or more of the types of finished panels listed in
Table 5. A detailed inventory of those plants represented in
Figure 8 is included in Appendix B. It should be noted that this
is not intended to represent a complete inventory of this segment
of the industry. In recent years rapid developments have
resulted in a multitude of finishing processes with a wide
variety of materials used and finished products produced. Such
developments have further resulted in an ever expanding number of
industrial operations being accomplished not only by the
manufacturers of the basic wood products, but also by custom
finishing plants not primarily associated with the timber
products industry.
Another portion of the industry included in Major Group 24
comprises establishments primarily engaged in turning and shaping
wood, and manufacturing various wood products such as cork and
sawdust products, various carved wood novelties, and a multitude
of machined and fabricated products. While an inventory of the
various industries within this category is not feasible. Figure 9
gives the number of such mills and indicates their distribution
by state and region.
In the U. s. there are currently 18 insulation board plants pro-
ducing over 330 million sq m (3,600 million sq ft) on a 13 mm
(0.5 in) basis yearly from wood or bagasse. Figure 10 cate-
gorizes these plants according to process and production. Seven
of these plants also produce hardboard to varying degrees, and
they all produce insulation board in either structural, mineral,
or finished form. A list of the plants and their locations is
given in Table 6. Of the 17 plants surveyed in this study, all
produced structural insulation board, and 13 also produced
finished insulation board. As for raw materials used by the
plants, a majority of 12 used softwood predominantly, three used
mostly hardwood, one mineral fiber, and one bagasse.
Much of the production growth of particleboard attributed to the
South and West can be explained by the concentration of plants in
the states of North Carolina and Oregon (Figure 11); there are 8
and 1tt particleboard plants in each state, respectively, and
Oregon produces one-third of the present total U.S. particleboard
production (Table 7).
Of the 76 plants now producing particleboard in the U* S., 69
produce platenboard (mat-formed board) and eight produce extruded
board (Table 8). The platenboard accounts for 98 percent of the
total particleboard production.
DESCRIPTION OF PROCESSES
The following discussions of processes in the timber products
industry are intended to provide a general knowledge of the
operations involved in the timber industry. These descriptions
are considered to be representative processes and are oriented
toward their use of water and generation of waste water.
30
-------
TABLE 5
TXPES OF FACTORY FINISHED PANELS
Softwood Plywood
Prefinished Plywood
Hardboard Faced
Paper Overlaid
Plastic Overlaid
Metal Overlaid
Special Printed Overlaid
Decorative Wall Panels
Preprimed Plywood
Coated Concrete Form
Hardwood Plywood
Prefinished Parcels
Hardboard Faced
Paper Overlaid
Plastic Overlaid
Vinyl Overlaid
Special Printed Overlaid
Plastic Laminated
Preprimed Plywood
Hardboard
Prefinished Panels
Factory Primed
Wood Grained
Plastic Overlaid
Vinyl Overlaid
Black-Dyed
Particleboard
Prefinished Panels
Filled Panels
Sealed Panels
Factory Primed
Veneer Overlaid
Plastic Overlaid
Vinyl Overlaid
Polyester Filled and Printed
31
-------
UJ
ro
FIGURE 9 WOOD PRODUCTS NOT ELSEWHERE CLASSIFIED
-------
OJ
O SUBCATEGORY I
SUBCATEGORY H
A SUBCATEGORY HI
FIGURE 10 MAP OF INSULATION BOARD LOCATIONS
-------
TABLE 6
INVENTORY OF INSULATION BOARD PIANTS
Abitibi Corporation
Blounstown, Florida
Armstrong Cork Company
Macon, Georgia
Boise Cascade Corporation
Internation Falls, Minnesota
The Celotex Corporation
Dubuque, Iowa
The Celotex Corporation
Marrero, Louisiana
The Celotex Corporation
L'Anse, Michigan
The Celotex Corporation
Sunbury, Pennsylvania
Flintkote Company
Meridian, Mississippi
Huebert Fiberboard, Inc.
Boonville, Missouri
Kaiser Gypsum Company, Inc.
St. Helens, Oregon
National Gypsum Company
Mobile, Alabama
Simpson Timber Company
Shelton, Washington
Southern Johns-Manville Products
Jarratt, Virginia
Temple Industries, Inc.
Diboll, Texas
United States Gypsum Company
Lisbon Falls, Maine
United States Gypsum Company
Greenville, Mississippi
United States Gypsum Company
Pilot Rock, Oregon
Weyerhaeuser Company
(Craig) Broken Bow, Oklahoma
34
-------
U)
Ul
MAT FORMED
MAT FORMED (under construction)
EXTRUDED
FIGURE 11 PARTICLEBOARD MANUFACTURING FACILITIES
-------
TABLE 7
PARTICLEBQARD PRODUCTION PIANTS BY GEOGRAPHIC AREAS, 1973
Geographic
Area
United States, Total
East
Pennsylvania
Indiana
Michigan
Wisconsin
Minnesota
South
Virginia
Florida
North Carolina
South Carolina
Georgia
Kentucky
Tennessee
Al abama
Mississippi
Arkansas
Texas
Louisiana
Oklahoma
All Types
76
9
2
2
1
2
2
40
7
1
8
3
2
2
1
1
4
4
3
3
1
Number Producing
Platenboard Extruded Board
69 7
8 1
1 1
2
1
2
2
34 6
5 2
1
6 2
2 1
2
1 1
1
1
4
4
3
3
1
36
-------
TABLE 7 PARTICLEBOARD PRODUCING PLANTS
BY GEOGRAPHIC AREAS, 1973
(Continued)
Geographic
Area
Number Producing
All Types Platenboard Extruded Board
West
Idaho
Montana
New Mexico
Arizona
Washington
Oregon
California
27 27
1 1
1 1
1 1
1 1
1 1
14 14
8 8
37
-------
TABLE 8
UNITED STATES PARTICLEBCftRD (MAT-FORMED) PRODUCERS
TABLE 8 UNITED STATES PARTICLEBOARD
(MAT-FORMED) PRODUCERS
ALABAMA
Giles & Kendall Company, Inc.
Maysville, Alabama
ARIZONA
Southwest Forest Industries
Flagstaff, Arizona
ARKANSAS
Georgia-Pacific Corporation
Crossett Division
Crossett, Arkansas
International Paper Company
Southern Kraft Division
Malvern, Arkansas
Permaneer Corporation
Hope, Arkansas
The Singer Company
Furniture Division
Trumann, Arkansas
CALIFORNIA
American Forest Products Corporation
Martell, California
Big Bear Board Products
Division of Golden State Building
Products
Redlands, California
Champion International
Anderson, California
Collins Pine Company
Chester, California
Georgia-Pacific Corporation
Ukiah, California
Hambro Forest Products, Inc.
Crescent City, California
Humbolt Flakeboard
Arcata, California
Sequoia Forest Industries
Division Wickes Forest
Industries
Chowchilla, California
FLORIDA
Florida Plywood
Greenville, Florida
GEORGIA
Georgia-Pacific Corporation
Vienna, Georgia
Weyerhaeuser Company
Adel, Georgia
IDAHO
Pack River Company
Tenex Division
Sandpoint, Idaho
INDIANA
Swain Industries, Inc.
Seymour, Indiana
Swain Industries, Inc.
Evanston, Indiana
KENTUCKY
Tenn-Flake Corporation
Mlddlesboro, Kentucty
LOUISIANA
Louisiana-Pacific Corporation
Urania, Louisiana
38
-------
TABLE 8.
UNITED STATES PARTICLEBOARD (MAT-FORMED) PRODUCERS
(Continued)
Olinkraft, Inc.
Lillie, Louisiana
Willamette Industries, Inc.
Duraflake South, Inc. Division
Ruston, Louisiana
MICHIGAN
Champion International
Gaylord, Michigan
MINNESOTA
Blandin Wood Products Company
Grand Rapids, Minnesota
Cladwood Company
Division Forest Poducts Sales Co.
Virginia, Minnesota
MISSISSIPPI
Champion International
Oxford, Mississippi
Georgia-Pacific Corporation
Crossett Division
Louisville, Mississippi
Georgia-Pacific Corporation
Crossett Division
Taylorsville, Mississippi
Kroehler Manufacturing Company
Meridian, Mississippi
MONTANA
Evans Products Company
Missoula, Montana
NORTH CAROLINA
Broyhill Furniture Company
Broyhill, North Carolina
Carolina Forest Products, Inc.
Wilmington, North Carolina
Georgia-Pacific Corporation
Whiteville, North Carolina
International Paper Company
Southern Kraft Division
Farmville, North Carolina
Nu-Woods Incorporated
Lenoir, North Carolina
Permaneer Corporation
Black Mountain, North Carolina
OKLAHOMA
Ward Industries, Inc.
Miami, Oklahoma
OREGON
Boise Cascade Corporation
La Grande, Oregon
Cascade Fiber Company
Eugene, Oregon
Cladwood Company
Division Forest Products Sales
Sweet Home, Oregon
Fibreboard Corporation
Clear Fir Products Division
Springfield, Oregon
Permaneer Corporation
Brownsville, Oregon
39
-------
TABLE 8
UNITED STATES PARTICLEBQARD (MAT-FORMED) PRODUCERS
^Continued)
Mexwood Products, Inc.
Albuquerque, New Mexico
Roseburg Lumber Company
Dillard, Oregon
Timber Products Company
Medford, Oregon
Weyerhaeuser Company
Klamath Falls, Oregon
Weyerhaeuser Company
Wood Products Division
North Bend, Oregon
Weyerhaeuser Company
Wood Products Division
Springfield, Oregon
Willamette Industries, Inc.
Duraflake Division
Albany, Oregon
Willamette Industries, Inc.
Brooks-Willamette Corporation
Division
Bend, Oregon
PENNSYLVANIA
Westvaco Corporation
Tyrone, Pennsylvania
SOUTH CAROLINA
Georgia-Pacific Corporation
Russellvilie, South Carolina
International Paper Company
Southern Kraft Division
Greenwood, South Carolina
TENNESSEE
Permaneer Corporation
Dillard, Oregon
Permaneer Corporation
White City, Oregon
Temple Industries ,
Diboll, Texas
Temple Industries
Pine!and, Texas
Bassett Furniture Company
Basset, Virginia
Champion International
South Boston, Virginia
Masonite Corporation
Waveryly, Virginia
Stuart Lumber Company
Stuart, Virginia
Union Camp Corporation
Franklin, Virginia
WASHINGTON
International Paper Company
Long-Bell Division
Longview, Washington
WISCONSIN
Rodman Industries, Inc.
Resinwood Division
Marinette, Wisconsin
Weyerhaeuser Company
Marshfield, Wisconsin
40
-------
Timber Harvesting
Timber may be harvested by one of four principal methods: (1)
"selective cutting," in which particular trees are chosen for
harvest; (2) "shelter wood," in which mature trees are removed
in (2) such a manner as to leave an adequate overstory; (3) "seed
tree harvesting," in which an area is clear cut to the extent
that only sufficient trees are left to bear seed for natural
reforestation; and (U) "clear-cutting," in which all trees are
removed from the harvested area.
Transportation of Logs and Other Raw Materials
The transportation of logs after leaving the forest is
accomplished primarily by truck and rail. In the Northwest, and
Alaska, where waterways are accessible, a large number of logs
are transported from the forest by navigable waterways. While
this method of transportation may be in ships or on barges, it
more commonly consists of large log rafts floating in the water.
In most cases, the logs are transported from as little as several
miles to as much as 161 km (100 miles) by truck or rail prior to
being transported in water. Furthermore, the logs may be sorted
in a fresh water pond before transport by truck or rail to the
large floating log rafts.
Because of the magnitude of these operations, water transport of
log rafts is generally limited to ocean or estuarine waters; but
some fresh water rafting is practiced, particularly in the power
supply reservoirs of the western U. S. Typically, a log raft is
composed of millions of bd ft of logs, loose or bundled, and
contained by perimeter logs. Log "driving", as practiced in the
early years of the industry, is almost non-existent today. Log
transportation in the South, East, and Midwest is almost
exclusively by truck.
Other raw materials transported in the timber products industry
may be broadly classified as fractionated wood. In the case of
total tree harvesting, the resultant chips are trucked from the
forest. While this type of immediate harvesting is a relatively
new practice in the industry, it is expected to increase in the
future. In general, wood chips resulting from in-field
processing are commonly transported by truck or rail. While
limited fluidization of chips, and hydraulic pipeline transfer,
is practiced in the pulp and paper industry, this technique is
used only as an inplant process in the remainder of the timber
products industry. Pneumatic transportation of bark or sawdust
is common for inplant transportation; however, between-plant
transportation is accomplished by rail and occasionally by truck.
Raw Material Storage
The harvesting of timber is seasonal in most parts of the U. S.
Consequently, log storage is often essential for continuous mill
production. When fractionalized wood is used as a raw material,
it is usually produced on a rather continuous basis, but it may
41
-------
arrive at the production site at irregular intervals, depending
on the distance and method of transportation. For example, a
train load of chips may arrive as infrequently as monthly at a
plant site and a stockpile of chips must therefore be maintained.
Management usually requires a "safety margin" of supply to
accommodate non-shipment during supply interruptions, e.g.,
railroad workers' strikes. A stockpile of chips to supply two or
three months production would be common. Generally, turn over
times for stockpiles of raw materials for insulation board plants
are less than one or two months and may be as low as three to six
days. Stockpiles for overseas shipment are normally quite large
and turnover times may be as long as several years.
Raw material storage is of considerable importance to the timber
products industry and a large amount of planning and capital
expenditure is involved. In addition, preservation of the raw
material while in storage is necessary to insure that the quality
and quantity of finished product is not impaired. Most of the
techniques used for raw material storage and preservation involve
the use of water and the ensuing production of water pollutants.
Logs may be stored either on the land or in the water. Those
logs stored on land may be stacked in piles ranging from 20 to 33
ft (6 to 10m) in height and hundreds of feet in length. These
piles, called "land decks", are usually one log's length in
width. When logs are land decked, there exists a tendency for
the ends of the logs to dry and crack. This "end-checking"
diminishes the amount of usable, top grade lumber that can be
obtained from the logs. To prevent end-checking it is not
uncommon to sprinkle the decks with water. Because of almost
continuous rains in the winter, spraying of land decks is
seasonal on the Northwestern coast. In other areas, such as the
Southeast, it is practiced on a continuous basis. A sprayed land
deck is referred to in the industry as a "wet deck." In some
cases, the effluent from the wet deck is collected and recycled,
but more commonly it is directly discharged. Quite often runoff
from the wet deck flows into a log pond.
Logs may be stored in water either singularly or in bundles. If
logs are stored as bundles, they are usually sorted on land, but,
in some cases, may be sorted in the water prior to storage.
There are usually two or more logs on the top of bundles that are
held above the water because of buoyancy and do not benefit from
the water storage; however, the number of logs that can be stored
in the same body of water is considerably greater when the logs
are bundled.
Logs may be stored in log ponds, river impoundments, or directly
in marine or estuarine waters. A log pond may be defined as a
body of water in which the influent and effluent are either small
or controlled. Most ponds range between 0.5 to 16 ha (1.2 to <*0
ac) in size. Typically one to three m (four to ten ft) in depth,
some may serve as catch basins for drainage areas many times
their size, though normally the associated drainage areas are
relatively small. Most log ponds serve as a means of
42
-------
transporting logs to a mill located on their shores. Because the
equipment at the mill that receives the logs cannot tolerate wide
fluctuations, in pond water level most log ponds attempt to
control pond level fluctuations. While there are a few log ponds
used only for storage and sorting, most are associated with some
type of mill operation. Log ponds are confined almost
exclusively to the Northwest.
An impoundment of sufficient depth for log storage may be formed
by the construction of a dam across a river. Logs are usually
transported to impoundments by trucks and the confinement serves
as a convenient means of sorting and storing the logs. An
impoundment is subject to the same types of operational
restrictions as log ponds with the primary difference being that
the flow of water through such an impoundment is usually much
greater than the flow through a log pond. In addition, these
reservoirs are usually public waters whereas log ponds are
privately owned. Some logs are stored in fresh water
impoundments when the primary function of the impoundment is
other than log storage. Power reservoirs and flood control
reservoirs are occasionally used for log storage, but the extreme
water level fluctuations characteristic of these waters make
operations difficult, limiting their usage. Logs are often
stored in estuarine and ocean waters, particularly in the
Northwest and Alaska, sometimes as long as 20 years. These logs
are placed into the water, sorted, and stored in a protected cove
or bay in piles away from the shore. Provision is made for water
level changes with the tides.
Wood chips, planer shavings, sawdust, and bark may be either raw
materials or waste products in different segments of the forest
products industry. As raw materials, fractionalized wood is
commonly placed in uncovered piles. The residence time of a
particle in the storage pile depends on the rates at which the
particles are supplied and utilized, as well as the operational
safety margin required by management. The production or usage
rate combined with the mean residence time establishes pile size.
A pile may be as small as a single truck load or as large as
several hectares and up to 30 m (100 ft) in height.
The particles are usually conveyed pneumatically onto the pile
and, the particles may be wetted during the blowing process, if
dust is a problem. In some cases, both the introduction of
particles to the pile and their removal occurs on the top of the
pile and results in some of the particles in the bottom of the
pile residing much longer than the mean residence time. In other
cases, particles are added and removed from one side of the pile
which causes those particles on the back side of the pile to have
a residence time much longer than the mean. Chip and planer
shaving piles used as raw materials in the particleboard industry
are usually stored inside buildings to keep the moisture content
of the chips as low as possible. Sawdust from very small
sawmills may be stored on-site in piles for more than one year,
and in many cases are left indefinintely.
43
-------
Sawmills and Planing Mills
The primary function of any sawmill is to reduce a log or cant to
a usable end product. The process employed to accomplish this
function consists of a combination of basic unit operations
including the following:
mill feed
log washing
debarking
sawing
resawing
edging
trimming
lumber handling
lumber finishing
It should be emphasized that several of the above operations may
not be practiced at a specific plant. The following process
description is a discussion of operations listed above including
a discussion of some of the variations within each unit that are
most common in the industry.
Mill Feed - The majority of mills utilizing land storage of logs
as opposed to water storage are fed by using a variety of loading
equipment, most commonly front-end loaders. The loader picks up
the log and simply places it on a ramp or deck equipped with
moving chains which transport the log into the mill. Some mills,
however, utilize ponds or flumes for mill feeding purposes.
Ponds may be used for sorting and washing prior to entering the
mill. Ponds and other water bodies used for storage are also
used for sorting purposes. Log flumes are utilized for mill
feeding by relatively few sawmills. In those mills utilizing
flumes, ponds or other water bodies for feeding, the logs are
floated to the mill entrance where a chain belt or bull chain
carries the logs out of the water and into the mill.
Log Washing - Log washing may be practical prior to barking
and/or sawing. While the desirability or necessity of this
practice cannot be clearly established, some of the reasons for
its use are as follows: (1) Where bark is utilized as a fuel,
log washing prior to barking reduces the amount of slag buildup
on boiler grates and,, consequently, reduces frequency of grate
washdown. Also, if bark is used for other purposed, a minimal
amount of grit is desirable; and (2) for mills not barking prior
to sawing, log washing increases saw life.
Log washing is accomplished by spraying water on logs from fixed
nozzles as the logs are tranported into the mill. In practice,
pressure and volume of water utilized vary from mill to mill, but
pressures are on the order of 6.8 atmospheres (100 Ib per sq in)
while the volume of water varies from less than 5 to 17 Ips (80
to 265 gpm).
44
-------
The future of log washing will be a function of one or more of
several considerations. If the trend in log storage is toward
deck storage, wet or dry, rather than toward storage in log
ponds, log washing may increase since log ponds serve the purpose
of cleaning logs. If the use of bark as an energy source
increases or decreases significantly log washing will possibly
vary proportionately because log washing reduces slag buildup on
boiler grates. If the market for "dirty" chips (i.e., chips and
bark mixed together) increases significantly, the desirability
for bark removal may decrease, while the desirability for log
washing would increase. Also, changes in the market value of
bark would likewise influence the degree of log washing and could
possibly result in the adoption of bark washing. Based on the
above considerations, the desirability of log washing will likely
increase in the future.
Headrig Operation - The term headrig is used by the industry to
include all the machinery which is utilized to produce the
initial breakdown of a log to boards, dimensions or cants. Thus,
a headrig includes the feed works, the setworks, the carriage and
shotgun, the headsaw, chipper or chipper saw and all the controls
associated with the above. The major types of headrigs and the
basic mechanical components will be discussed.
The basic headrig consists of a single diesel or electric powered
circular saw and a log carriage. The carriage is a platform on
wheels equipped with hydraulic or electric setworks which hold
the log as the carriage moves parallel to the saw. The setworks,
which are controlled by the sawyer, position the log for sawing.
The carriage is powered by a shotgun which may be air, hydraulic,
or steam powered. The shotgun is a long, circular tube in which
a ram is inserted. One end of the ram is attached to the
carriage and the other is fitted with a pistonhead. A compressor
or pump pressurizes the working fluid behind the piston and thus
powers the carriage in one direction. By rotating a valve spool
the sawyer can reverse the direction of the piston and the
carriage. Figure 12 gives an equipment layout for a hydraulic
shotgun.
Another type of single saw headrig utilizes a band saw. A
typical band saw is 25cm to 30cm (10 to 12 in) wide, 11 to 12 m
(35 to UO ft) long, and is mounted on two saw wheels, one above
the other, each with a diameter of two to three m (six to ten
ft). The band saw is tensioned and driven by the saw wheels and
may be one-sided or two-sided. The log is placed on the carriage
and sawn as it passes the saw which is moving vertically
downward.
Ahead of either the band saw or the circular saw may be a
chipper. The chipper is used to square the side of the log prior
to sawing and thus eliminates the slab which would otherwise
result from sawing.
45
-------
RAM
O1
PISTON' VALVE SPOOL SAFETY
VALVE
PUMP
HEAT EXCHANGER
FIGURE 12 HYDRAULIC SHOTGUN
-------
Multiple saw headrigs consist of the following basic types:
Log gang mill
Double band or quad band headrig
Scrag mill
Chipping headrig
The log gang or Swedish gang saw cuts by means of a series of
parallel saw blades mounted in a frame that moves up and down as
the log is fed through. The double band headrig utilizes a pair
of band saws while a quadband headrig utilizes two pairs of band
saws in tandem to accomplish the initial log breakdown. The
scrag mill is generally utilized for small diameter logs and
consists of one or more pairs of circular saws with each pair in
tandem.
The purpose of the multiple saw headrig is to increase production
efficiency by eliminating the need for several passes by the
headsaw. This task may also be accomplished by a chipping
headrig. In this type of headrig the debarked log is fed through
an infeed section to bottom, side, and top chipping heads. The
chipping heads are automatically set according to the diameter
and shape of the log so that only that portion of the log which
will not produce marketable lumber is chipped away. Thus, after
chipping, the log has been completely profiled such that
marketable lumber can be readily produced by subsequent
operations. The subsequent operations are similar to those
following other headrigs with the exception that from the
chipping headrig the profiled log must proceed immediately to
further breakdown without turning or changing position.
The nature of subsequent sawing operations will depend on the
degree of breakdown accomplished in the headrig and the desired
end product from the mill. In general, the function of these
operations is to reduce the width or thickness of the lumber or
to square the edges or ends. The basic unit operations following
the headrig are gang sawing, resawing, edging, and trimming. The
gang saw may be the reciprocating type, as previously described,
or a set of circular saws usually of a movable, double arbor
type. The gang saw reduces a cant to lumber of desired
thickness. Resaws are usually vertical band saws and are used to
saw thick boards into thinner ones. These may be single, double,
or quad band resaws. Following resawing, or remanufacturing as
it may be termed, the lumber enters the edger. Edgers vary
widely in size and capacity but usually consist of one stationary
circular saw and one or more circular saws that can be moved
laterally on the arbor to permit ripping different widths. Trim
saws are circular saws used to square the ends of the lumber and
to remove serious defects.
Following edging and trimming, the rough green lumber is sorted
and stacked. The lumber may first flow into a "green chain" and
be graded, sorted, and stacked, or it may be graded and sorted by
placing it in appropriate sorting troughs. If the lumber is to
be marketed green, it may be passed through a preservative bath.
47
-------
usually pentachlorophenol, prior to stacking. The duration of
the dip is usually less than one minute.
Dying of lumber is accomplished by either air seasoning or by
kiln drying. Air seasoning is accomplished by segregating,
coating, and piling. Segregation is done based upon green board
weight so that a given pile will dry at the same rate. Prior to
its being stacked, the lumber may be treated with chemicals by
spraying, brushing, or dipping in order to prevent blue stain and
other fungal attack. Various coatings may also be applied to the
end of the lumber to retard checking. The most common of these
is paraffin or other wax emulsions. The lumber is then stacked
in such a manner as to provide adequate air circulation and left
to dry for a period of time that may extend to several months.
Kiln drying is accomplished by placing green lumber into a
humidity and temperature controlled kiln. The kiln is heated by
steam or other means, generally by indirect radiation from coils.
Air circulation is maintained by forced draft or by natural
circulation. Humidity is controlled by steam sprays. The lumber
is stacked mechanically or manually outside the kiln with sticks
of wood used to separate the boards. The stacks are then moved
into the kiln where they will remain until the desired moisture
content is reached. Temperature, humidity, and drying time will
vary with kiln type, wood species, initial moisture content, and
various other factors. In general, however, kiln drying is
accomplished in two to five days at dry-bulb temperatures ranging
from 49 to 82 C (120 to 180 F)„ For some cases, high temperature
drying, i.e., above 93 C (200 F) is also employed to reduce
drying time.
Dried lumber is quite often planed to desired smoothness. The
surfacing tools used are planer knives attached to a rotating
cutterhead. The quality of finish is a function of the number of
knives, the rotations per minute of the cutterhead, the feed rate
of lumber through the planer, and other factors. Lumber may be
surfaced on one, two, or four sides by the addition of an equal
number of cutting heads.
After planing the lumber may proceed through one or more of the
following processes:
Preservative dipping
Staining
End-coating
Moisture proofing
Preservative application is generally accomplished by the methods
previously discussed for green lumber handling. Staining,
usually with a water base material, is done merely to produce a
more pleasing color in the finished lumber. This is generally
accomplished by a spray nozzle as the lumber passes through the
spray compartment. Excess spray is recirculated. End-coating
prevents the ends of the lumber from checking while it is in
storage or in service. This is generally done by spraying the
48
-------
end of the lumber with any of various materials such as paint or
wax emulsions. Any material which will seal the end of the
lumber and is easily applied will suffice. Moisture resistant
compounds are sometimes sprayed on the finished lumber to
increase durability and resistance to weathering. compounds
specifically formulated for this purpose are available from
several manufacturers and are applied in a similar fashion to the
stain application discussed above. These materials are generally
water soluble.
As previously mentioned, a sawmill is a combination of some or
all of the above unit operations. The process diagrams shown in
figures 13 through 15 will serve to illustrate some of these
possible combinations and some possible mill layouts.
Figure 13 illustrates a process layout for a small rough green
sawmill. Figure 14 illustrates the combination of wet and dry
deck storage . of logs, with a small to medium size band sawmill
and a planing mill. Figure 15 gives a possible layout for a
medium to large sawmill.
It should be noted that planing mills may exist in combination
with sawmills or may be independent mills buying from a number of
suppliers. It should also be noted that other unit operations
may be present at a sawmill or planing mill. The most common of
these additional operations is edge or end jointing of lumber in
sawmills and production of millwork in planing mills. These
types of operations will be discussed below.
Miscellaneous Operations - There are a number of wood products
which are produced by further processing or manufacturing of such
primary forest products as lumber, plywood and board products.
The large number of such products prohibits a discussion of
detailed process descriptions for each individual product and
since for the most part there is little or no process water used
and little or no waste water generation in these processes, a
thorough discussion of each manufacturing method is unnecessary.
Basically the production of miscellaneous wood products may be
characterized as one or more of the following unit operations:
machining, fabrication, and by-product utilization.
Representative examples of the specific products which are
considered under these operations are given below.
shakes door trim wooden frames and sash
shingles baseboards window trim
excelsior moldings box cleats
barrel staves wooden panels spools
gun stocks stair railings flooring
wooden bowls toothpicks matches
49
-------
MILL FEED
MECHANICAL DEBARKER
CIRCULAR HEADSAW
EOGER AND GANGSAW
TRIM SAW
GREEN CHAIN
SHIPPING
FIGURE 13 PROCESS DIAGRAM OF ROUGH GREEN SAWMILL
50
-------
DRY STORAGE
i— WET STORAGE
MECHANICAL DEBARKER
BAND HEADSAW
VERTICAL RESAW
EDGER
TRIM SAW
GREEN END
,
KILN DRYING
PUMP
WATER
RESERVOIR
HOG CHIPPER
SHIPPING
AIR DRYING
PLANING MILL
SHIPPING
FIGURE 14 PROCESS DIAGRAM OF BAND SAWMILL
51
-------
Ul
N)
PRELIMINARY BARK
PROCESS AND
COLLECTING
FIGURE 15 PROCESS DIAGRAM MULTIPLE HEADRIG SAWMILL
-------
Fabricating
barrels laminated beams baskets
doors laminated decking wirebound boxes
windows jointed lumber wooden boxes
prefabricated buildings wooden pipes crates
mobile dwellings trusses
Bv-Product Utilization
wood flour ornamental bark bark mulch
toilet seats chair seats pressed logs
Machining - Machining is the process of shaping wood to a desired
form and is accomplished by such basic mechanical operations as
splitting, turning, carving, drilling, sawing, grooving, and
lathing. Thus, shingles are manufactured from a block of wood by
sawing at a slight angle to produce a flat piece of wood with one
end thicker than the other. Moldings, trim, and other mill work
are produced by lathing and grooving a piece of lumber to a
desired shape. Cleats, used in crate manufacturing, are pro
duced by sawing lumber into small shapes to be used in crate
manufacture. A multitude of products are produced from lumber by
such simple machining operations, but none are of significance
with respect to waste water generation.
Fabrication - Fabrication is accomplished by mechanical fasteners
or by use of adhesives. Where mechanical fasteners are employed
no water usage is necessary. This is the case, for instance, in
the manufacture of mobile homes, trusses, barrels, baskets,
pallets, crates, and other fabricated products. The use of
adhesives normally necessitates a certain amount of waste water
because of cleanup operations.
The adhesives most commonly used in the wood products industry
are given in Table 9. Of these, casein glue, protein, polyvinyl
acetate, urea formaldehyde, melamine urea resin, and phenol
resorcinol resins are most frequently used in fabrication. All
of these are water soluble and, with the exception of polyvinyl
and resorcinol resin, require water in preparation.
Fabrication with adhesives consists of jointing, adhering a flat
sheet to a frame, or joining lumber face to face to produce
structural materials. The standard glue joints are given in
Figure 16. These joints are used for three basic purposes: to
join lumber side-to-side-grain, end-to-side-grain or end-to-end-
grain. Urea, modified urea, melamine urea, polyvinyl, casein,
and phenol resorcinol are the most common adhesives for jointing.
The finger joint is the predominant end to end joint utilized in
the industry. Finger joints are produced by machining the ends
of two pieces to be joined into fingers, applying adhesives to
the fingers by brush or special roller applicators, and joining
the pieces together. Curing time, temperature, and pressure will
depend on the resin used. The amount of resin which must be
applied varies with the type and purpose of the joint and is
53
-------
WOOD ADHESIVES:
TABLE 9
PROPERTIES, HANDLING AND USE GUIDE
CURING PREPAR-ADDI- EXTEN- DURA- ADVAN-' DISAD- "SPEC. &
TYPES METHOD SOLVENT ATION TIVES DERS APPLICATION PRESSURE BILITY TAGES VANTAGES STANDARDS
Animal Glue A.C-l.D J-l E N,0 - V-1,2,3,4 W-1,2 a f,h,q c h
Casein Glue A.D-2 0-1,2 E U,
Protein Blend A,D-2,D-3 1.0-1 E U
Soybean Glue A.D-3 1,0-1 E 0
Polyvinyl Acetate B,C-2 J-l E N
Melamine Resin B.D-2.D-3 • I,K.L E 0
Urea Resin B,D-1,2,3 l,J-i,K,L E 0
Modified Urea B.D-1,2, 1,0-1,
Resin D-3 K.L E 0,
Urea/Melamine B,C-1,D- , i,K,L
Resin 2,3 E 0
Urea Resorcinol B,C-l,D-L E,F N
Epoxy Resin B I,J-1,K H N
A Natural Origin D continued j
B Synthetic Resin 3 Several ingredients
C Liquid needed
1 Solution E Water
2 Emulsion F Water and Alcohol «
D Powder G Hexane and Methyl
1 Dry Base Material ethyl Ketone L
2 All ingredients H 100% solids M
in powder, add to I Hot press
water
a Dry, Interior use only f Fast setting
b High cost 9 Low cost
c Poor water resistance h Fed, Spec, MM
d Thick glue lines craze 1 Fed. Spec, m
e. Generates heat in mix- J Fed. Spec. MM,
ing, requiring small k Fed. Spec. MM
mixes 00181
P P - V-l ,2,3;
V-l
U V-l
V-l ,2, 3,
b V-
b,K,U V- ,3,4
V, ,3,
Q Q S 4
V- ,3,
S 4
V- ,3
S
V-l, 3
0 - 4
V-l, 3
4
-V-l, 3
4
U - K,$,I ,U V-l
S V- ,3
V-l, 3
S
V- ,3,4
Cold Press N
1 Room Temp. 0
7Q°F P
2 50° or above Q
Kiln Cure R
(14Q°F or higher) S
Radio Frequency
Electrical Resistance T
Heating U
1 Fed. Spec.
m CS-35
4-A-100 n CS-45
•l-A-125 o Mil.. Spec.
1-A-188 p Mil, Spec.
4-A-
4 W- ,2,3 a,Z q
H-l.2,3 a,Z q
W-1,2,3 a,/ q
4 W-1,2,3 a f
W- ,2,3 X,Y X
W-1,2,3 Y,Z q
r-'' Y*z .
;-.*. Y,Z _
r-*' Y'z .
W-1,2 z,a
3 f
W-1,2,3, Y.Z
4 f
W- .2.3 X.Y f
W-1,2,3 x X
W- ,2,3 X
X
W- ,2,3 Y X
Ready to use
Mix with water
Synthetic Latex
Furfuryl alcohol
Wheat Flour
Walnut Shells or
Pecan Shells
Co-cob for Furafil
Soluble Blood
MMM-A-193
MIL-A-22397
MIL-A-46051
i,m
m,n
n
c 1
b p
d m.j
k,m
m .
m
m
b m
b
m,n,o,p,k
b m,n,ofp,k
b m,n,o,p,k
e m
V 1 Spreader
2 Dip
3 Brush
4 Spray
W 1 100 psi
2 150 psi
3 175 psi
4 Squeeze rolls
X Waterproof
Y Highly water
resistant
Z Moderately water
resistant
-------
SIDE-TO-SIDE-GRAIN JOINTS: (A) plain (B) tongue-ond-groove
A.
B.
C.
D.
E.
F.
G.
H.
J.
END-TO-SIDE-GRAIN JOINTS I (A) plain; (B) miter, (C)dowel,
(D)mortise and tench, (E)dado tongue and rabbet ,{F)slip or
lock corner , (G)dovetail, (H) blocked ,(J)tongue and groove.
A.
B.
C.
D.
E.
F.
G.
END-TO-END-GRAIN JOINTS : (A)end butt, (B)platn scarf,
(C) finger, (D) serrated scarf ,(E) hooked scarf, (F)flnger,
(G)double-slope scarf.
FIGURE 16
55
-------
usually measured only indirectly by testing the joint for
strength. Similar assembly steps are utilized for end-to-side-
grain joints and for side-to-side-grain joints. End-to-side-
grain joints are employed in fabricating door frames of all
types, window frames, and in lock corner boxes. Side-to-side-
grain joints are utilized in flooring, decking, and in solid
flush doors.
The application of a flat sheet to a frame is illustrated in door
manufacturing. The flat sheet may be a door skin of various
types which is pressed against a preglued frame in which case the
adhesive used may be resorcinol, polyvinyl, contact cement, or
some non-synthetic glue. This type of fabrication is also
utilized to some extent in the building construction industry for
adhering panels to frames or for adhering plywood to floor
joists. The adhesive must likely to be used in this application
is a mastic construction adhesive which is a thick dispersion of
various elastomers in an organic solvent.
The third major fabrication operation to be considered is that of
joining lumber face to face to produce structural members such as
beams, arches, and timbers. Whether the process employed is
automatic or manual, it basically consists of pregluing, gluing,
fabricating and finishing. Pregluing operations include such
previously mentioned operations as lumber drying, preservative
dipping or spraying, planing, grading, end or edge jointing, and
cutting to length. The dressed lumber, usually two in pine or
fir, is end jointed or cut to the desired length of the final
member. The lumber used to produce these laminates is graded and
sorted. The high strength clear lumber is utilized in the high
stress areas of the final product, which for beams is the top and
bottom layers, while lower grade lumber is used for the lower
stress areas of the member.
Following pregluing the laminates are spread with glue, commonly
resorcinol and phenol resorcinol resin, by a double roll spreader
or by an extruder applicator. The resins are mixed with a
catalyst in small batches and are then fed to the roller-
spreaders under pressure. The extrusion spreader requires no
mixing tank, except for catalyst preparation, as the catalyst and
resin are mixed in a helical mixing chamber within the spreader.
According to the Handbook of Adhesive Bonding, following gluing
the laminates are assembled to form the beam and the resin is
cured. Curing may be accomplished by cold setting, heat curing,
or radio frequency curing. During curing, pressure is applied to
the member. Special laminating clamps, generally of the screw
type with rocker heads apply the required pressure. Both
straight beams and curved arches can be produced in this manner
by different arrangements of the clamp systems. After curing,
which may take up to 2U hours, the member is finished by sanding
or planing and prepared for shipment. A typical process diagram
for a laminated timber manufacturing process is given in Figure
17.
56
-------
DRESSED LUMBER
FINGER JOINTING
GLU I NG
l_ AY UP
CURING
Fl NISH I NG
PACKAG ING
SHIPMENT
GLUE STORAGE
AND MIXING
FIGURE 17 PROCESS DIAGRAM FOR LAMINATED TIMBER MANUFACTURE
57
-------
By-product utilization covers those products in SIC 24 which
utilize waste materials such as bark and sawdust as their raw
material and are not covered elsewhere. As none of these
products are significant sources of waste water, only a brief
discussion of some of the major products follows:
Wood flour - Produced by attrition from planer dust or sawdust.
Pressed logs and briquettes - Produced by injecting sawdust into
a mold under heat and pressure without chemical binders.
Mulch - Produced by hogging bark or sawdust to a fine particle
size and possibly adding nitrogen in the form of liquid ammonia
by spraying the ground bark.
Ornamental bark - Produced by classification of bark into a
desired size category.
Molded Products - A small number of plants produce miscellaneous
molded wood items from wood particles. The process consists of
applying resin which is generally of the thermoplastic type to
the wood particles following molding with heat and pressure. The
resin content may be in the range of 30 - 40 percent by weight.
The term by-product utilization as defined in this document does
not include the manufacture of insulation board and
particleboard. These processes are discussed below.
Insulation Board
Insulation board can be formed from a variety of raw materials
including wood from a softwood and hardwood species, mineral
fiber, waste paper, bagasse, and other fibrous materials. In
this study, only those processes employing wood as the primary
raw material are considered. Plants utilizing wood may receive
it as roundwood or fractionated wood. Fractionated wood can be
in the form of chips, sawdust, or planer shavings. Figure 18
provides an illustration of a representative insulation board
process.
When roundwood is used as a raw material, it is usually shipped
to the plant by rail or truck and stored in a dry deck before
use. The round wood is usually debarked by drum or ring barkers
before use, although in some operations a percentage of bark is
allowable in the board. The barked wood then may be chipped, in
which case the unit processes are the same as those plants using
chips exclusively as raw materials. Those plants utilizing
groundwood normally cut the logs into 1.2 to 1.5 m (4 to 5 ft)
sections either before or after debarking so that they can be fed
into the groundwood machines. The equipment used in these oper-
ations is similar to that used in the handling of raw materials
in other segments of the timber products industry.
Fiber Preparation Operations
Ground wood is used in a number of insulation board plants in the
U.S. It is usually produced in conventional pulpwood grinders
equipped with coarse burred artificial stones of 16 to 25 grit
58
-------
Ul
WOOD •
(50)
STOCK
CHEST
FORMING
MACHINE
TO ATMOSPHERE
A
I
I
DRIER
TO FINISHING
(25)
(I)
(15)
(1.5)
(50)
(98)
(X)
WATER IN
WATER OUT
APPROXIMATE FIBER CONSISTENCY IN PROCESS
FIGURE 18 INSULATION BOARD PROCESS
-------
with various patterns. The operation of the machine consists
primarily of hydraulically forcing a piece of wood against a
rotating stone mounted horizontally. The wood held against the
abrasive surface of the revolving stone is reduced to fiber.
Water is sprayed on the stone not only to carry away the fibers
into the system, but also to keep the stone cool and clean and
lubricate its surface. The water spray also reduces the
possibility of fires occurring from the friction of the stone
against the wood.
While most fractionated wood is purchased from other timber
products operations, in some cases it is produced on site.
Currently, little chipping occurs in the forest; however, in the
future this is expected to become a major source of chips. Chips
are usually transported to the plants in large trucks or rail
cars. They are stored in piles which may be covered but are more
often exposed. The chips may pass through a device used to
remove metal grit, dirt, and other trash which could harm
equipment and possibly cause plate damage in the refiners. This
may be done wet or dry. Pulp preparation is usually accomplished
by mechanical or thermo-mechanical refining.
Bagasse consists of the woody fibers and pith fractions remaining
from the milling of sugar cane. It is delivered to the board
plant by rail and truck from storage at the sugar mills in either
loose piles or in bales. Moisture content can vary from 10
percent to 80 percent depending on the method of storage,
Rigorous washing of the bagasse to remove remains of field trash
and mud, in addition to the pith fractions, is a critical and
necessary step in preparation for plant use.
Refining Operations - Mechanical refiners basically consist of
two discs between which the chips or residues are passed. In a
single disc mill, one disc rotates while the other is stationary.
The feed material passes between the plates and is discharged at
the bottom of the case. The two discs in double disc mills
rotate in opposite directions, but the product flows are similar
to a single disc mill. Disc mills produce fibers that may pass
through a 30 or 40 mesh screen, although about 60 percent of the
fibers will not pass through a 65 mesh screen. The discs plates
generally rotate at 1,200 or 1,800 rpm or a relative speed of
2,400 or 3,600 rpm for a double disc mill. Plate separations are
generally less than 0.10 cm (0.040 in). A variety of disc
patterns are available and the particular pattern used depends on
the feed's characteristics and type of fiber desired.
A thermo-mechanical refiner is basically the same as a disc
refiner except that the feed material is subjected to a steam
pressure of 4 to 15 atm (40 to 220 psi) for a period of time from
one to 45 minutes before it enters the refiner. In some cases,
the pressure continues through the actual refining process.
Pre-steaming softens the feed material and thus makes refining
easier and provides savings on horespower requirements; however,
yield may be reduced up to 10 percent. The longer the
60
-------
pretreatment and higher the pressure, -the softer the wood
becomes. The heat plasticizes primarily portions of the
hemicellulose and lignin components of wood which bind the fibers
together and result in a longer and stronger fiber produced.
Following the refining operation,, the fibers produced are
diluted with water to a consistency amenable to screening. For
most screening operations, consistency of approximately one
percent fiber is required. Screening is done primarily to remove
coarse fiber bundles, knots, and slivers. The coarse material
may be recycled and passed through secondary refiners which
further reduce the rejects into usable fibers for return to the
process. After screening, the fibers produced by any method may
be sent to a decker or washer.
Decker Operations - Deckers are essentially rotating wire-covered
cylinders, usually with an internal vacuum, into which the
suspension of fibers in water is passed. The fibers are
separated and the water is often recirculated back into the
system. There are a number of reasons for deckering or washing,
one of which is to clean the pulp. When cleaning the pulp, water
may be sprayed on the decker as it rotates. The major reason for
deckering, however, is for consistency control. While being
variable on a piant-to-piant basis, the consistency of the pulp
upon reaching the forming machine in any insulation board process
is critical. By dewatering the pulp from the water suspension at
this point, consistency can be controlled with greater accuracy.
Washing of the pulp is sometimes desirable in order to remove
dissolved solids and soluble organics which may result in surface
flaws in the board. The high concentration of these substances
tends to stay in the board and during the drying stages migrate
to the surface. This results in stains when a finish is applied
to the board.
After the washing or decking operation, the pulp is reslurried in
stages from a consistency of 15 percent to the 1.5 percent
required for the formation process. The initial dilution of
approximately five percent consistency is usually followed by
dilutions to three percent and finally, just prior to mat
formation, a dilution to approximately 1.5 percent. This
procedure is followed primarily for two reasons: (1) it allows
for accurate consistency controls and more efficient dispersion
of additives, and (2) it reduces the required pump and storage
capacities for the pulp. During the various stages of dilution,
additives are usually added to the pulp suspension. These range
from 5 to 30 percent of the weight of the board depending on the
product used. Additives may include: wax emulsion, paraffin,
rosin, asphalt, starch, and polyelectrolytes. The purpose of
additives is to give the board desired properties such as
strength, dimensional stability, and water absorption resistance.
After passing through the series of storage and consistency
controls, the fibers in some cases pass through a tune-up
refiner. The fiberous slurry, at approximately 1.5 percent
61
-------
consistency, is then pumped into a forming machine which removes
water from the pulp suspension and forms a mat.
Forming Operations - While there are various types of forming
machines used to make insulation board, the two most common are
the fourdrinier and the cylinder forming machines. The
fourdrinier machine used in the manufacture of insulation board
is similar in nature to those used in the manufacture of
hardboard or paper. The stock (pulp slurry) is pumped into the
head box and allowed to flow onto an endless traveling screen.
The stock is spread evenly across the screen by special control
devices and an interlaced fibrous blanket, referred to as a mat,
is formed by allowing the dewatering of the stock through the
screen by gravity. The partially formed mat traveling on the
wire screen then passes through press rollers, some with a vacuum
applied, for further dewatering.
Cylinder machines are basically large rotating drum vacuum
filters with screens. Stock is pumped through a head box to a
vat where a mat is formed by use of a vacuum on the screen
imposed on the interior of the rotating drum. A portion of the
rotating drum is immersed into the stock solution as indicated in
Figure 19. As water is sucked through the screen, a mat is
formed when the portion of the cylinder rotates above the water
level in the tank and the required amount of fiber is deposited
on the screen. The mat is further dewatered by the vacuum in the
interior of the rotating drum and is then transferred off the
cylinder onto a screen conveyor where it passes through roller
presses as utilized in fourdrinier operations.
Both the fourdrinier and the cylinder machines produce a mat that
leaves the roller press with a moisture content of 50 to 70
percent and the ability to support its own weight over short
spans. At this point, the mat leaves the forming screen and
continues its travel over a conveyor. The wet mat is then
trimmed to width and cut off to length by a traveling saw which
moves across the mat on a bias making a square cut without the
necessity of stopping the continuous wetlap sheet.
After being cut to desired lengths, the mats are dried to a
moisture content of five percent or less. Most dryers now in use
are gas or oil fired tunnel dryers. Mats are conveyed on rollers
through the tunnel with hot air being circulated throughout.
Most dryers have eight to ten decks and various zones of heat to
reduce the danger of fire. These heat zones allow for higher
temperatures when the board is "wet" (where the mat first enters)
and lower temperatures when the mat is almost dry.
The dried board than goes through various finishing operations
such as painting, asphalt coating, and embos sing. Those
operations which manufacture decorative products will usually
have finishing operations which use water-base paints containing
such chemicals as inorganic pigments, i.e., clays, talc,
carbonates, and certain amounts of binders such as starch,
protein, PVA, PVAC, acrylics, urea formaldehyde resin, and
62
-------
VACCUM
IMPOSED
AREA
HEADBOXN
(INFLOW) V
SCREEN
CONVEYOR TO
ROLLER PRESS
FIGURE 19
63
-------
malamine formaldehyde resins. These are applied in stages by
rollers, sprayers, or brushes. The decorative tile then may be
embossed, beveled, or cut to size depending on the product
desired.
The board sometimes receives addditional molten asphalt appli-
cations to one surface. It is then sprayed with water and
stacked to allow adjustment to a uniform moisture content.
Hardboard is produced by some insulation board plants. Allowing
the mats to age, redrying them, and pressing the mat by large
steam heated hydraulic presses, consolidates the mat to the
desired density.
Finishing operations such as sanding and sawing give the board
the correct dimensions. Generally, the dust, trim, and reject
materials created in finishing operations are recycled back into
the process.
Particleboard
In the majority of cases the raw materials used to produce
particleboard are wood residues of any species from other timber
product processes. However, roundwood is used in a few
instances. At this time, most particleboard in the U.S. is
produced from mill residues such as planer shavings, sawdust, and
plywood trim. Furniture waste, particleboard trim, veneer cores,
and other chip sources are used occasionally. In cases where a
particleboard plant is a part of an integrated complex, a
substantial part, or all of the raw materials are supplied by
other operations in the complex.
In other countries, logging residues are the primary source of
raw materials. Logging residues arise from complete or near
complete utilization of forested land and include chips, tops,
and standing dead trees. It is projected that the use of forest
residues in the U. S. will increase in the future, possibly
causing a modification of the production process because of the
necessity of washing logging residues to remove grit, sand, and
other trash.
There is research presently being conducted in the U. S. and
abroad on the utilization of other raw materials such as bark,
wastepaper, and even municipal garbage (the paper and wood
components after separation). The widespread utilization of
these raw materials to produce specific grades of particlebaord
will depend largely on both economics and scarcity of raw
materials. In the case of bark utilization, the problems of
disposal may be the catalyst needed to develop a utilization
scheme. Sander dust (presently being used by some European mills
in amounts up to 10 percent in boards) may be utilized in the
future because of environmental considerations stemming from both
air pollution and solid waste disposal problems.
64
-------
The raw materials are shipped to the plant by rail or truck and
stored in silos, covered sheds, or outside piles until needed.
The fractionated wood is then conveyed pneumatically or
mechanically to the particle preparation area. Before being
reduced into particles, the raw materials pass through metering
bins in order that a uniform feed rate can be achieved. (In some
cases, the silos storing the received raw materials have metering
capabilities.) The metered wood then goes to the particle
preparation stage. Figure 20 shows a process flow diagram for
particleboard production.
There are three basic steps is producing mat formed
particleboard: particle preparation, mat formation, and mat
consolidation. Incorporated within these primary operations are
particle drying, additive blending, board cooling, and board
finishing operations. It should be noted that differences in
equipment among plants are common and the equipment is described
in the general case only.
Classification - Prior or subsequent to particle preparation, it
is usually necessary to classify the wood by size by the use of
vibrating screens or air classifiers. The classification is done
primarily to remove particles of undesired shape and size which,
if allowed to remain, would increase the resin requirements,
present problems during manufacture, or produce defects in the
product. Another reason for classifying particles is to allow
the use of the finer particles to form the face of the board and
the coarser particles to form the core.
Screen classification is usually accomplished by vibrating
screens. The wood is fed onto one end of the screen and the
vibrating action of the screen transports the wood along the
length of the screen. The rejects which are too large to pass
through the screen are recycled back into a system such as a
hammermill which reduces the size. The fines which are
unacceptable for the process are discarded. Although in some
cases air classification provides sharper fractionization, it can
also involve greater difficulties in operation and controls. The
use of air classification allows for the instantaneous adjustment
of the classification process. However, it also entails a larger
energy consumption than do screens,
Particle Preparation - The four principal methods of particle
formation in use are hammermills, flakers, mechanical, and
thermo-mechanical refining. Hammermills and similar type
machines use free swinging hammers of steel strips or impellers
with stiff arms to reduce material by a beating action. These
are relatively simple machines with low cost wear parts. On
certain raw materials and with the proper choice of hammermill,
operating spped, feed rates and screen size the hammermill
produces acceptable particle geometry at an acceptable cost.
Under certain operating conditions, a high percentage of dust may
be produced. These machines are used primarily for coarse jobs
such as the reduction of large reject chips to a size acceptable
for feeding flakers or refiners. These machines are also used to
65
-------
WOOD
ADDITIVE
BLENDING
•^ PORTION M
0 FINISHING
FIGURE 20 PARTICLEBOARD PROCESS FLOW DIAGRAM
-------
produce some core stock in particular operations. After the
initial impact, particles that are still too large are pushed
through a screen or grate at the periphery. The screen controls
the size of the particles produced,
Flakers are used extensively in the particleboard industry for
core stock and to some extent for face stock. Different flakers
use either roundwood or residues as the feed; however, the basic
concept of the machines, the use of knives to reduce the feed
wood to particles, is the same. In the case of wood residue
flakers, an impeller throws the residue against a ring of knives.
The flakes thus produced are generally 0.05 to 0.15 cm (0.020 to
0.060 in) in thickness. Thirty to 40 percent of the particles
produced are in the screen size range of four to ten with only
two to ten percent being larger under normal conditions. Flakers
used on roundwood operate on a similar principle in that logs are
fed to a rotating set of knives. The resulting flakes are larger
than those produced from residue but the thicknesses are
comparable.
Mechanical refiners consist of two discs between which the chips
or residues are passed. In a single disc attrition mill there is
one rotating disc. The feed material passes between the rotating
disc and a stationary plate and is discharged at the bottom of
the case. Double disc mills have two discs rotating in opposite
directions, but the product flow is similar to the single disc
mill. The product of disc mills is generally an elongated rod
shape. The disc plates generally rotate at 1,200 rpm or 1,600
rpm (a relative speed of 2,400 rpm or 3,600 rpm for a double disc
mill). Plate separations are generally less than 0.10 cm (0.040
in). A variety of disc patterns are available and choice depends
on the feed's characteristics and type of product desired. The
products from these mills are generally used as face stock, i.e.,
the fiber is deposited on the surface of the board during
formation to provide a smooth surface. When phenolic resins are
used, the resin frequently is added during refining.
A thermo-mechanical disc refiner is basically a disc refiner
receiving feed material which has been subjected to steam
pressure four to 15 atm (60 to 220 psi) for a period of time (15
seconds to 3 minutes) before entering the refiner. The pressure
continues through the actual refining (in the disc area), in most
cases.
Pre-steaming softens the feed material and thus facilitates
refining and reduces horsepower requirements. The longer the
pretreatment and higher the pressure, the softer the wood
becomes. The heat plasticizes primarily the hemicellulose and
lignin components of wood which bind the fibers together. In
addition, a longer and stronger fiber is produced.
Drying - Following particle preparation, the particles are dried
by heat to achieve a uniform moisture content. The moisture
content of the particle is critical and is different for various
operations; however, the preferred moisture content of the
67
-------
particles at the drier exit is usually between 5 and 15 percent,
Driers are heated by gas, oil, wood residue unsuitable for
particleboard (sander dust, etc.)* or a combination of the above,
but gas and oil fired driers are most common. The energy
required per ton of particles is not an accurate measure of drier
efficiency as the inlet moisture content will vary considerably
depending on species and whether green or dry wood is used,
Drier efficiency is usually discussed in terms of energy
requirements per pound of water evaporated in the drier.
The rotary jet drum drier is essentially a horizontal pneumatic
drier in which high velocity heated air is directed in such a
manner that a sprial flow of particles is achieved through the
drier.
Another type of drier in use is situated vertically and uses a
fluidized bed principle. The particles enter the drier and are
suspended by hot air entering from the bottom. The particles
become lighter as they dry and are emitted from the top of the
unit.
A third type of drier in use consists of a tube bundle rotating
in a trough. The particles dry in contact with the tube bundles
while vanes fitted to the bundles convey the particles. In some
cases the particles enter a preheater before entering the drier.
The preheater is usually heated by exhaust gases from the main
drier.
Because of the nature of the drying operation (heating wood
particles), there is always a risk of fire. Although maintenance
and operational procedures generally keep fires at a minimum,
dryer fires can still be expected to occur several times per
year.
The most important operation in terms of the quality of the bond
of the board and one of the more critical operations in the
particleboard plant is the application of additives. The
quantity of resin and the method of application are important
factors in both cost and quality of the finished product.
The two most common types of resins used in manufacturing
particleboard are urea-formaldehyde and phenol-formaldehyde, with
the former accounting for approximately 90 percent of the usage
in the U. S. Resin content in the board will range from 6 to 12
percent in the surface layers and U to 8 percent in the core. It
is sometimes desirable to add 0.25 to 1.0 percent catalyst to
urea resin to promote faster curing of the resin. The catalysts,
consisting of acids or acid salts such as ammonium chloride, or
ammonium sulfate promote faster curing by lowering the pH, The
major disadvantage of adding a catalyst is a shortened resin pot
life. Ammonium hydroxide may be added to retard the action of
the acid until the pressing operation.
In addition to resins, a petroleum base wax sizing is usually
added to the particles in the blenders. Sizing increases liquid
68
-------
water resistance considerably and vapor resistance to some
extent.
The additives are applied to the particles in blenders of various
types, A blender is basically a machine in which wood particles
are agitated while a spray of resin and other additives are added
in a manner that will allow uniform coverage of the additives on
the wood particles. Each wood particle has adequate exposure in
the blender to the spray. This insures a coating of the
necessary quantity of resin and other additives which is
necessary to achieve the desired properties in the final board.
The additives may either be mixed together prior to blending or
sprayed into the blender separately.
Although most plants currently use continuous blenders there are
some batch blenders in use. A batch blender is operated by
adding wood to a mix tank and agitating with a proportional
amount of additives. While this system is considered by the
industry to be reliable it is not economically feasible for large
plants and is rarely used.
Continuous blenders consist of a longitudinal trough with a
center shaft carrying mixing arms and spray nozzles for the
dispersion of additives. There are two common types of
continuous blenders. In one type the mixing arms rotate and
cause a dense wood-air suspension. Spray nozzles located along
the top eject atomized resin and other additives onto the
particles in a uniform manner. The atomization is accomplished
by compressed airr pressure spraying, or, in some cases,
centrifugal means.
The most common type of continuous blender currently in use is
the curtain spray blender. Particles are fed into one end of the
blender in a falling curtain effect. Auxiliary curtains are
created by the agitating action of paddles fixed to rotating
mixer arms. Resin and other additives are added to this system
by spray nozzles located in the end plate on the feed side of the
blender. The curtain spray blender creates a thorough mixture of
all the materials that will go into a board and many new plants
are choosing this type of blender. One reason the trend is to
the curtain spray blender is the availability of cooling jackets
for reduction of the inside temperature. Blender cleaning is a
necessary part of all blender operations since excess resin, as
well as resin already on particles, sometimes adheres to the
paddles and walls of the blenders. It is advantageous to
maintain this buildup at a minimum level in order that the
blenders can be used for longer periods of time and maintenance
costs can be reduced. Since both urea and phenolic resins are
thermosetting, the cooled blender will have less adhesion on the
walls and will require cleaning less often. Also, the curtain-
spray blenders have fewer nozzles to clean or plug up.
Formation of a uniform mat of particles is the single most
important objective in a particleboard manufacturing process. A
69
-------
lack of uniformity will result in physical property variations,
curing problems in the pressing cycle, and will tend to make the
particleboard more subject to warp. Poor mat formation may also
result in poor surface and edge characteristics which in turn
affect the salability of the board.
Forming machines meter the particles from a surge area and spread
them uniformly across the width of the machine onto a caul or
moving screen. In addition, there is usually a particle
orientation or leveling device to further provide for uniform
formation. A surge area in a forming machine insures a
continuity of material flow into the formation devices. It is
important to maintain a uniform level in the surge bin. Without
bulk density control there can be no uniform mat formed as the
wood is generally metered volumetrically. The wood is metered
onto the caul or moving screen by the means of rakes, picker
rolls, or other such devices, although some machines use air as a
metering technique. After the particles are distributed onto the
caul or moving,screen, there are usually leveling screws or
picker rolls or shaveoffs to level the mat. To produce a layered
board, the particles, which have been previously divided into
fine and coarse materials, are laid by different machines to give
fine surfaces and a coarse core to the board.
A variation of the layer board formation is the graded density
board. This is formed by air classification and a gradual
reduction of particle size occurs from the core to the surface.
Graded density is accomplished by feeding particles at a
volumetrically controlled rate through a central air distribution
mechanism. The horizontal air flow acts as an air separator and
the heaviest particles drop almost vertically, while the finer
particles are thrown to the far edges.
Pressing - After formation the mats are conveyed to the pressing
area. A prepress is often used when a caul-less system is being
used or a thick board is being produced. The prepress, which may
be of the single opening hydraulic type or the continuous roller
typer is used to impart some integrity to the board before it
enters the hot press. Also, before entering the hot press, the
mats are usually trimmed by trim saws with the trim being
recovered as furnish and fed back to the forming system.
The hot press is used to consolidate the mats under pressure and
cure the resin with the heat from the steam heated platens. Some
newer plants use resonance frequency devices to help cure the
resin by heating the board internally with the use of high
frequency radio waves. Resonance frequency pressing reduces
press time and allows for the production of boards of greater
thickness.
Pressing is accomplished by either multi-opening hydraulic
presses, single opening hydraulic presses, or, occasionally, a
continuous press. Multiopening presses consist of a number of
shelves with each shelf containing a heated platen. The mats are
stacked into a loader which in turn allows mats to be placed on
70
-------
all the shelves at once. Each press is usually constructed so
that platens close simultaneously in order to prevent board
defects. Single opening presses do not require loading racks.
They operate in a similar manner as the multi-opening presses.
The presses operate at pressures as great as 69 atm (1000 psi)
and at temperatures of 132°C to 20U°C (270°F to 400°F) depending
upon the type of resin the process employed. Continuous presses
consist of heated rolls and produce a continuous ribbon of board.
After the ribbon leaves the press it is cut to the lengths
required and sanded.
Extruded Particleboard
The raw materials utilized for extruded particleboard are usually
dry wood with a large proportion of furniture scrap. Particle
preparation is primarily accomplished by hammermills. After
particle preparation and classification, the wood particles are
coated with resin and wax by the previously described batch
method. The coated particles are forced through a heated dye by
hydraulic rams and the board emerges in a continuous strip which
is cut to size. Since boards produced by the extrusion process
are considerably stronger in one direction they are usually
cross-banded with wood veneers to provide strength and stability.
Finishing Operations
Finishing is generally the final step, with the exception of
packaging, in any timber products manufacturing process. It may
consist of surface smoothing such as sanding or planing, covering
with liquid coatings or covering with various sheet materials, or
combinations of these operations. With the exception of the
finishing processes previously discussed in connection with
sawmilling and particleboard and insulation board manufacturing,
the manufacture of prefinished panels and the finishing
associated with mill work and molding are the major product areas
of significance for the purposes of this study.
Factory finishing of wood-based panel products involves the
application of a wide variety of finishing materials of various
formulations and the employment of various methods of
application. In general, however, finishing materials can be
classified as either liquid materials or sheet material overlays.
Liquid finishes are supplied to almost all types of wood-based
panels including softwood plywood, hardwood plywood, hardboard
and particleboard. For any particular finishing operation, the
finishing material used and the method of application are
primarily dependent upon the type of panel being finished as well
as the desired final properties of the finished product. Liquid
finishing materials are most commonly applied by one of the
following methods: spray coating, curtain coating, direct roll
coating, reverse roll coating, or knife coating. Each of these
methods usually involves the employment of a coating machine
through which the panel substrates pass in a horizontal position,
on a continuous basis by way of a conveyor system.
71
-------
Spray coating is a method used on almost all types of substrates
and is used in the application of various liquid finishing
materials including clear and pigmented paints and coatings. The
spray of material is most commonly produced by fixed gun spray,
reciprocating spray, or rotary arm spray equipment. The spray
equipment is commonly enclosed in a spray booth to provide fire
and air pollution protection by removal of both the solvent fumes
and the spray mist generated from spray coating operations. Two
types of spray booths include a water wash type, which employs a
thin water curtain as the filtering media, and a dry type which
employs a dry filter element. Spray coatings are especially
important in the application of certain textured surfaces.
Curtain coating is a common method of applying various types of
coatings to flat, smooth panel substrate surfaces. The curtain
coater produces a thin, uniform curtain-like film of liquid
material which falls by gravity to the panel substrate as it
passes through the coating zone. The curtain-like film is
produced as the liquid material passes through over head knife
gates under either a gravity head or a pressure head. Excess
curtain flow is caught by a return trough and is returned to the
receiving tank for reapplication.
The direct roll coater is probably one of the most commonly used
applicators for flat stock panel substrates. A roll coater
generally consists of an applicator roll, a metering roll, and a
feed or support roll. The applicator roll and the metering roll
rotate in opposite directions on the upper side of the panel
substrate and the liquid material is flooded over and between
these two rolls. The metering roll, of smaller diameter than the
applicator roll, serves to control the thickness of the liquid
material film on the applicator roll which applies the material
directly to the panel substrate as it is passed through the
coating device by the feed roll on the under side of the panel.
Excess liquid material is caught by a recovery pan and is
returned to the receiving tank.
Reverse roll coating is particularly important in the application
of high viscosity filler materials of high solids content. The
reverse roll coater basically consists of the same three
components of the direct roll coater plus an additional
component, a reverse wiping roll which rotates in the opposite
direction of the applicator roll. The essential purpose of the
wiping roll is to more effectively force the material into the
surface voids of the panel substrate and to provide a smooth
troweled surface coating. As with the direct roll coater, the
excess material is collected and returned to the material supply
for reapplication.
Knife coating is also especially suited for applying high
viscosity liquid finishing materials of high solids content. The
knife coater basically consists of an applicator roll, a duplex
doctor blade assembly and support and feed rolls. The applicator
roll first applies an excess amount of material to the panel
substrate in much the same manner as described above for direct
72
-------
roll coating. The duplex doctor blade consists of a rigid
bullnosed blade which first scrapes off the majority of the
excess material and a more flexible blade which scrapes the
surface of the panel clean, leaving only the surface voids filled
with coating material. The excess material is also collected for
reapplication.
Liquid finishing materials vary widely and cannot be defined as
completely as the methods employed in their application.
Finishing operations on all types of wood-based panel substrates
usually involve the application of one or more of the following
materials: patching materials, sealers, stains and dyes, prime
coatings and fillers, base or ground coatings, grain printing
inks and top coatings. Patching materials are usually applied to
hardwood plywood panels as the first step in the manufacturing of
prefinished wall panels. The patching material, a thick putty-
like substance, is manually applied using a flat blade putty
knife to fill knot holes and other large surface defects in the
hardwood face veneer of the panels.
Sealers of many different formulations are usually applied to
almost all wood-based panels at sometime during the finishing
operations. A variety of synthetic resin sealers are applied to
softwood plywood, usually for the purpose of protection of the
surface until final in-use finishing such as painting or
varnishing. Sealers or primers of pigmented paint or lacquer
types are often applied to hardwood plywood and particle board to
provide a firm foundation for subsequent coatings. Sealers are
usually applied by spray coating, roll coating, or curtain
coating equipment.
Stains and dyes are used to some extent in the finishing of
various types of wood-based panels. Conventional finishing of
softwood plywood is commonly accomplished by spraying or flooding
light or heavily pigmented penetrating stains which will not curl
or flake upon checking of the panel face. Dying of hardboard is
becoming less important but is still practiced to some extent in
making floor tiles and similar products.
Prime coatings and fillers and frequently applied to nearly all
types of wood-based panels. Prime coated panels are either
marketed as such or receive further finishing at the factory
level. The primary purpose of prime coating and filling is to
improve the control and the quality of finish of materials to be
applied in subsequent finishing operations on the prime coated
panel. Prime coating of softwood plywood is often coupled with
the use of a medium density paper overlay. The combination
serves to improve surface qualities for paint finishes to be
applied by the ultimate user. Fillers or high viscosity, heavily
pigmented paint materials are applied to the face veneers of
hardwood plywood and to the surfaces of particleboard to a great
extent in the manufacturing of prefinished panels. The purpose
of applying the filler material is to fill the small voids in the
panel surface to provide a smooth flawless surface for subsequent
finishing operations. Filler materials are usually applied
73
-------
either by a knife coater or a reverse roll coater. Presently,
most filler materials are of a non-water solvent base, however,
because of air pollution controls on solvent emissions from
finishing lines, water base fillers are becoming more widely
used.
Factory finishing of insulation board is a common practice in the
case of both ceiling and interior wall panels which are being
factory painted. Special fire-retardant paint formulations are
often applied, usually by spray coating, to obtain an irregular
surface to aid in sound absorption.
A Forest Products Journal investigation shows that prime-coatings
are especially important in the manufacturing of hardboard
panels. High viscosity, heavily pigmented paints which often act
as fillers are applied to the hardboard panels employing either
knife coaters or reverse coating of hardboard panels.
Base or ground coatings differ from prime coatings in that the
former are usually associated with grain printing operations
commonly used on hardboard panels, particleboard panels and
hardwood plywood panels with face veneers of plain, unfigured
character or color. After a filler coat is applied and cured a
base coat is applied with either a curtain coater, roll coater or
spray coater which provides a ground color for the grain to be
printed. After curing the ground coat, grain designs are printed
by one or more commonly by two or three roller or plate type
printing machines to provide the panel with a simulated wood
grain finish.
Presently, most inks used for grain printing are non-water base
but water base inks are expected to become more popular in the
near future.
Top coatings are often applied as a final factory finish coating
and are used to a great extent in the finishing of nearly all
prefinished panels. Top coatings for prefinished hardwood
plywood panels are usually either a lacquer type or a synthetic
conversion varnish type of which the alkyl urea resin type is the
most important. Top coatings for hardboard are of various types
including alykl or melamine based varnishes. Clear and pigmented
polyester and acrylic finishes are transparent lacquers. Water
base top coats are also being used on various types of prefin-
ished panels.
Figure 21 shows a process flow diagram for the manufacturing of
printed grain wall paneling. Although the process shown is not
necessarily typical of any particular plant or type of panel, it
should serve here to illustrate some of the processes that have
been discussed with respect to the application of liquid
finishing materials to wood-based panels. As shown in the
diagram, the panels are introduced into the continuous
prefinishing line and are first cut to size and then rough
sanded, usually by large belt sanders. The V or U-grooves are
then machine cut and painted. Currently groove paints are mainly
74
-------
MANUAL
PATCHING
I- *
FILLING
OVEN
•*
TRIMMING
CUT-OFF
GROOVE
ROUGH
SANDING
GROOVE
rf_
DRYING
PAINTING
GRADING
}f
PACKING
CUTTING
FILLER
DRYING
OVEN
DRYING
" F
4
\
FINE
SANDING
TOP
COATING
*
^
BASE
COATING
OVEN
DRYING .
fe
W
*
^
OVEN
DRYING
GRAIN
PRINTING
4-
SHIPPING
CONVEYOR TRANSFER
MANUAL TRANSFER
FIGURE 21 PROCESS FLOW DIAGRAM FOR THE MANUFACTURE OF PRINTED GRAIN
PRE-FINISHED PANELING
75
-------
non-water solvent base but water-base paints are gaining
popularity for this application. After the groove paint is oven
dried, the panels are then machine filled by either a reverse
roll coater or a knife coater and the filler is then oven dried.
The filled panels are sometimes fine sanded before the
application of the base coat which also must be dried. The
imitation grain is then printed on the panels and dried, followed
by the application of the top coat. After top coat drying the
panels are then graded and packaged for shipment.
Overlaying operations in the factory finishing of wood-based
panels involves various types of sheet materials being bonded to
the base panel by glue or cement materials of various types. The
primary purposes of overlaying are to mask defects, protect
against weathering, provide a base for paints and other finishes,
increase the strength, hardness or abrasive resistance of the
surface, provide decorative effects, or a combination of any of
these attributes. The most important types of overlaying
materials are resin-impregnated papers, special plastic film and
aluminum foils. Resin-impregnated paper overlays are used on all
types of wood-based panels. The resin-impregnated papers of
widely varying resin content are usually bonded to the wood-based
panel under high temperatures and pressures. Temperature ranges
of 93 to 1U9°C (200 to 300 F) and pressure of 8 to 28 atm (118 to
412 psi) are employed depending on the resin type and content and
on the type of base panel being overlaid. Except in the
production of abrasion resistant surfaces, most overlaying
operations involve low pressure systems. For surfaces where high
resistance to abrasion is required, high pressure laminating of a
clear melamine protective sheet is often added to the overlayed
panel.
The most common types of resins used in resin-impregnated paper
overlaying are melamine formaldehyde, phenol formaldehyde,
polyesters, and acrylic types. The first three types are
thermosetting resins which undergo permanent physical and
chemical changes through the application of heat and pressure.
In contrast, the acrylic types are thermoplastic resins which
soften and may be reformed under pressure and heat. The melamine
and phenol-formaldehyde resins are usually added to kraft paper
at the pulp mill to produce either high or medium density
impregnated paper to be overlaid at the panel finishing plant.
High density impregnated paper requires no additional adhesive
for bonding to the wood substrate while medium density overlays
usually require a phenolic glue line in the overlaying operation.
The polyester impregnated papers are also self-bonding while
overlaying of the acrylic types usually employs a phenolic glue
line.
Special plastic films of various types may be used to overlay
almost all types of wood—based panels. Vinyl resin films are
being used to a large extent. Polyvinyl chloride films are used
in producing textured and printed decorative panels. Clear vinyl
films are also important in finishing hardwood plywood wall
panels. Bonding of the vinyl film is usually accomplished
76
-------
through the application of either polyvinyl acetate water-
emulsion adhesives or solvent-type elastomeric adhesives. The
polyvinyl acetate is a thermoplastic resin formed by
polymerization of vinyl acetate. The adhesive is either applied
to the wood-based panel or to the vinyl film and is often dried
to remove the solvent, then heat activated before joining the two
materials. The overlayed panel is usually pressed between two
rubber rollers to improve the bond.
Aluminum foil overlayed panels are being produced on a relatively
small scale basis. Bonding of the foil is often accomplished by
using modified phenolic resin film glue and employing a press
operation. Adhesives used in the overlaying operations discussed
above can be applied in a number of ways, but the most common
method is by roll coating the adhesive onto the panel substrate
prior to the application of the sheet material overlay.
Other types of overlaying operations practiced on a relatively
small scale basis involve the overlaying of hardboard and veneers
onto particleboard panel substrates. Adhesives used in these
operations are most commonly phenolic or urea resin glues used in
conjunction with a hot pressing operation. However, vinyl glues
and various contact cements can also be used in a cold pressing
operation.
Figure 22 shows a simplified process flow diagram for the
manufacturing of vinyl film overlayed panels. Although this is
not typical of all overlaying operations, it is presented here to
illustrate some of the basic operations involved in overlaying
wood-based panels. The panels are first fed into the continuous
system and are often sanded prior to the application of the
adhesive which is commonly applied by a roller coater. Often the
solvent is dried immediately after application of the adhesive
and then heat activated before application of the vinyl film.
After the vinyl sheet material is applied, the composite panel is
then passed between two rubber rollers to improve the bond.
Excess vinyl material on the edges of the panel is trimmed flush
with the panel edge. The finished, overlayed panels are then
graded and packaged for shipping.
Molding is produced by planing, grooving or otherwise
manufacturing through a molding machine. Finishing generally
consists of priming and painting, or filling followed by wood
grain printing or vinyl film application. The finishing
materials utilized are generally the same as those utilized for
prefinished panels.
77
-------
FEED
SANDING
ADHESIVE
APPLICATION
ADHESIVE
DRYING
-*
PRESSING
^
VINYI FM M ^ MrriuATinr
APPLICATION ADHESIVE
VINYL FILM
TRIMMING
TO S
>• CONVEYOR TRANSFER
MANUAL TRANSFER
FIGURE 22 PROCESS FLOW DIAGRAM FOR VINYL FILM OVERLAYING
78
-------
SECTION IV
INDUSTRY CATEGORIZATION
In the development of effluent limitation guidelines and
standards of performance for the timber products industry, it was
necessary to determine the differences which may form a basis for
subcategorization of the industry. The rationale for
subcategorization was based on differences and/or similarities in
the following factors: (1) quality and quantity of waste waters
produced, (2) the engineering feasibility of treatment and the
resulting effluent reduction, (3) plant age, (4) plant size, (5)
raw materials used, (6) manufacturing process employed, and, (7)
the costs of treatment and control.
Effluent guidelines limitations and standards of performance for
the barking, veneer, plywood, hardboard and wood preserving
portion of the timber products processing industry were published
as 40 CFR Part 429, subparts A through H. This regulation
appeared in the Federal Register, Volume 39, 13942 (April 18,
1974).
A previous study by the Midwest Research Institute for EPA
concerning pollution from silvicultural activities discussed
timber harvesting. Therefore, while various aspects of timber
harvesting may be subject to future guidelines, this portion of
the timber product industry is not studied nor subjected to
effluent limitation guidelines in this document. Also not
subject to recommended effluent guidelines in this document are
(1) the storage of logs in waters other than self-contained
ponds, (2) the transportation of logs in water, (3) the storage
of lumber and other end products, (4) dry decking of logs, and
(5) storm water runoff from yards and roofs. In Section V, waste
water characteristics will be discussed for the storage of logs
in waters other than ponds. In Section VII, management
techniques for the reduction of pollution will be discussed for
transportation and storage of logs in waters other than ponds,
storage of lumber and other end products, dry decking, and storm
water runoff.
As outlined in the description of the industry in Section III,
the timber products industry consists of many different
manufacturing processes. Several factors affecting quality
and/or quantity of waste produced, the engineering feasibility of
treatment and resulting effluent reduction, and the cost of
treatment were considered significant with regard to identifying
potential subcategories for these processes. The factors
considered included: (1) process employed, and variations, (2)
nature of raw materials, (3) plant size and age, (4) land
availability, (5) climatic relationships, and (6) process water
requirements.
79
-------
In consideration of the above factors, the segment of the timber
products industry included in this study and subject to proposed
effluent limitations has been subcategorized as follows:
(1) Wet storage,
(2) Log washing,
(3) Sawmills,
(4) Finishing,
(5) Particleboard manufacturing,
(6) Insulation board manufacturing, and
(7) Insulation board manufacturing with steaming or
hardboard production.
The rationale for the above categorization is as follows:
Process Variation
The production of products from wood and wood by-products, as
indicated in Section III, involves considerable variation in
process operations. These variations, whether caused by the end
product desired, raw materials used, processing method used, or
other factors, can result in considerably different waste water
characteristics, applicable control and treatment alternatives,
and costs of control and treatment alternatives. Of all factors
considered, process variation is the most significant in
determining possible subcategorization. The possible sub-
categories resulting from consideration of this factor are:
(1) Wet storage in water
(2) Wet storage on land
(3) Dry storage
(4) Fabricating operations in which mechanical fasteners
or non-water soluble adhesives are used
(5) Fabricating operations in which water soluble adhesives are
employed
(6) Finishing operations employing water soluble materials
(7) Finishing operations employing non-water soluble
materials
(8) Log washing
(9) Sawmills and planing mills
(10) Insulation board production employing little or no
steaming of raw furnish
(11) Insulation board production employing extensive steam-
ing and having no hardboard production, or employing
limited steaming with hardboard production
(12) Insulation board production empoying steaming and
having hardboard production
(13) Particleboard production
Ponds as discussed Section III, are distinct process variations
in that logs may remain in a log pond for long periods of time or
for periods of time seldom exceeding a week.
Land storage of logs or other raw materials is distinct from
water storage in that the waste water generation from land
80
-------
storage results from spraying water on the logs or from
precipitation runoff while the pollution associated with water
storage results from the leaching of substances directly into the
water. Furthermore, except in the case of sprayed land decks
without recycle, the flow produced by land storage is dependent
on sufficient rainfall while the flow from storage ponds may be
continuous, at least on a seasonal basis.
However, information regarding the treatment and control
reliabilities, and the waste water characteristics variabilities,
is limited. It is not feasible to subcategorize the storage of
logs to a more specific level than wet storage.
The processes involved in fabrication result in a highly
concentrated glue waste. In some cases these wastes may be
similar to the glue wastes produced by plywood manufacturing
while in other cases they are quite different, depending on the
type resin used.
Those process variations which emplo'y mechanical fasteners
generate no waste water. Those employing organic soluble resins,
while requiring cleanup of equipment generate a volume of water
sufficiently small that it can be contained and reused. Those
operations employing water soluble resins constitute, the majority
of the fabricating industry and generate a volume of waste water
sufficiently large that treatment and disposal is necessary.
The unit process of finishing produces a unique waste water
requiring special handling and treatment. The waste water
primarily consists of various concentrations, depending on the
amount of wash water used, of paint and other finishing
materials. The characteristics of the waste water vary widely,
depending on the ingredients used in the finishing substances. A
substantial variation occurs, however, depending on whether water
soluble or non-water soluble materials are used.
Another process variation that results in a different waste water
stream is the unit operation of log washing. Log washing does
not result in the same degree of leaching effects that occur in
ponds because of the short contact time of the water with the log
and results in an effluent with a considerably higher grit
content than the effluents from other timber products operations.
Because of the different waste water characteristics resulting
from log washing, the unit process is considered to be a separate
subcategory.
Sawmills and planing mills are considered a separate subcategory
in that the processes employed may require the use of water, but
with proper control no discharge of waste water pollutants is
achievable.
In the production of boards the process of insulation board
manufacturing and particleboard manufacturing have definite
differences, as described in Section III, and result in waste
waters that require different control and treatment technologies.
81
-------
While the production of insulation board products from wood
involves similar operational procedures in any plant,
considerable process variation can and does occur. These
variations may be caused by the end product desired or by the
practices and procedures of plant management. There are two
process variations which produce significant differences with re-
gard to waste water generation in the insulation board industry.
These variations involve the effect of steaming or not steaming
raw material before refining and whether or not a plant produces
hardboard products. Although waste water flows and solids
concentrations will vary little between subcategories, BOD, will
vary considerably. When steaming is done prior to the refining
there is a release of soluble organics that are not released when
no steaming is done. This in terms of BOD loading approximately
doubles the waste load. The effect of producing hardboard
products is that hardboard products require additives of a
different nature than plants producing insulation board products.
Also there is more refining of the wood necessary for the pro-
duction of hardboard type products. These will be discussed in
more detail in Section V, Water Use and Waste characterization.
Because of significant differences in waste water loads, the
insulation board industry has been further divided into two
subcategories: plants that do not steam their raw furnish, and
plants that steam their raw furnish or produce hardboard
products,
The production of particleboard involves similar operational
procedures in all plants; however, there are process variations
that can occur. These variations do not affect waste water flows
or concentrations considerably. The biggest variation derives
from the production differences inherent between those plants
producing extruded particleboard, and those that produce mat-
formed particleboard.
While extruded particleboard accounts for less than one percent
of the total production and plants are much smaller, the reported
daily waste water flows vary little from the largest mat-formed
particleboard plant because the components of the waste water
essentially are the same. Process variations are not considered
as a technical element necessitating subcategorization and
because of no significant differences in water usage, the
particleboard industry has not been divided into further
subcategories.
Nature of Raw Materials
No subcategorization resulted from consideration of the nature of
raw materials. It would be expected that species type would have
an effect on the characteristics of waste waters from timber
products operations, particularly those in which an appreciable
source of pollutants is the leachates from wood and wood
products. However, as shown in Section V, Water Use and Waste
Characterization waste water characteristics do not show
82
-------
sufficient differences to warrant further subcategorization based
on species type.
A more significant effect is produced by whether the raw material
is in the form of fractionalized wood or whole logs. As shown in
Section V, whole log storage in wet or dry decks produces
significantly different waste water characteristics from piles of
chips, planer shavings, bark, and other similar materials.
While approximately 30 percent of all insulation board plants
utilize mineral wool as a portion of their raw material, it was
found that this practice did not cause sufficient variations in
waste water loads to warrant subcategorization. One insulation
board plant uses bagasse as its sole raw material. All
particleboard plants utilize wood as a raw material. Although
the raw material may be in the form of roundwood, chips, planer
shavings, or sawdust, a significant variation in waste water
loads with variation in raw materials was not found. Because a
major waste stream from a plant comes from the washing of the
additive blending areas, a difference in additives will affect
the waste water quality. However, this is not considered to be
an effect significant enough to warrant further
subcategorization.
Plant Size and Age
Operations in the timber products industry range in size from
"backyard" businesses to complexes with thousands of employees.
In most cases size of operation and waste water volume and
pollutant load will be proportional and thus, on a basis, size
has a negligible effect on waste water characteristics.
In addition, cost of control and treatment technology tends
toward a constant factor on a unit product basis. In larger
operations, economy of scale is applicable to various degrees
but, while this must be given consideration, it does not in
itself justify subcategorization of the industry. On the other
extreme, small operations have treatment and disposal options
such as retention, land spreading, and trucking to landfill, that
are impractical on larger scales. These factors are taken into
account in the development of control and treatment alternatives
in Section VII, but do not constitute a basis for
subcategorization of the industry.
Plant age cannot be considered as a basis for subcategorization
because operations vary in age of equipment as well as
structures, i.e., plants generally undergo a continuous
modernization of facilities and the actual "age" of an
installation is indeterminable. Furthermore, the age of
equipment does not necessarily affect waste water generation.
More important factors are operation and maintenance of the
equipment.
83
-------
The only trend related to age observed in this study is that of
particleboard plants in the western U. S. tending to be of more
recent origin than those in the East. However, as indicated in
Section V, no differences in waste water generation could be
discerned for the two groups.
Nature of Water Supply
The quantity and quality of fresh water supplies utilized by
timber products operations were originally considered to be
possible elements for industry subcategorization because of
potential prohibitive factors that could be encountered in
control and treatment. However, despite the fact that the
industry tends to use the most available water supplies and a
wide variation in the nature of the water supplies result, no
detectable effects on control and treatment have resulted from
this study. Therefore, nature of water supply is not regarded as
a technical element necessitating subcategorization.
Plant Location and Land Availability
The location of a timber products plant may be significant in
terms of climatic effects on operations and control and treatment
technology, . the availability of adequate land for the
construction of treatment facilities, and other factors. These
factors have received consideration in the development of control
and treatment technology (Section VII) in which, for example,
various evaporation rates were considered for different sections
of the country and different treatment alternatives were
developed for varying amounts of available land.
Despite the fact that plant location and land availability can
affect the practicality of various control and treatment methods
as well as costs, no rational subcategorization can be based on
this consideration because of the wide variability of conditions.
The considerations taken in the development of control and
treatment technology are considered adequate for the development
of effluent limitations guidelines and plant location and land
availability are rejected as technical elements necessitating
subcategorization.
Water Usage
Several operations in the timber products industry experience a
unique usage of water. These are the storage of logs in
estuaries, rivers, and impoundments, and the transportation of
logs in water. The water pollution generated by these operations
is unique in that no waste water streams are produced; the
pollution results from direct contact of the operations with
surface water bodies. Any attempts to characterize the
pollutional effects result in water quality considerations, and,
while certain management techniques as discussed in this document
can be effective in reducing pollution, no treatment technology
is applicable to these operations. Therefore, as a result of the
nature of water usage, the operations of log storage in
84
-------
estuaries, rivers, and impoundments, and the transportation of
logs in water are considered as a separate subcategory of the
timber products processing industry. However, as previously
stated, these operations are not subject to effluent limitations
at this time.
SUMMARY OF SUBCATEGORIZATION
The segments of the timber products processing industry
considered in this document have been separated into the
following subcategories for the purpose of proposing effluent
limitations guidelines and new source performance standards.
These subcategories are defined as:
1. Wet Storage. The wet storage subcategory includes the
holding of unprocessed wood, before or after bark
removal, i.e.f logs, in self-contained bodies of water
(ponds) or land storage of unprocessed wood where water
is sprayed on the wood. This operation is commonly
referred to as wet decking.
2. Log Washing. The log washing subcategory refers to the
process of passing the wood raw material through an
operation where water under pressure is applied to the
log for the purpose of removing foreign material from
the surface of the log before further processing.
3. Sawmills and Planing Mills. The sawmills subcategory
includes timber products processing operations of
sawing, resawing, edging, trimming, planing and/or
machining.
U. Finishing. The finishing subcategory includes
operations that follow edging, trimming and planing.
These operations include drying, dipping, staining, and
coating, moisture proofing and by-product utilization
not otherwise covered by effluent limitations guidelines
and standards.
5. Particleboard. The particleboard manufacturing
subcategory includes the manufacture of particleboard.
Particle board is, defined as board products that are
composed mainly of distinct particles of wood or other
ligno-cellulosic materials not reduced to fibers which
are bonded othether with an organic or inorganic binder.
(A component of particleboard furnish may be fibrous
material.)
6. Insulation board. The insulation board manufacturing
subcategory includes facilities that produce a
fiberboard from wood in a fibrous state. The board has
a density of less than 0.5 g/cu cm (31 Ib/cu ft). The
manufacturing process involved does not involve
85
-------
subjecting the wood material to a pressure created by
steam.
Insulation board Manufacturing with Steaming or
Hardboard Production. This subcategory includes the
manufacture of insulation board at facilities that
either steam condition the raw material before refining
or that produce hardboard at the same facility.
86
-------
SECTION V
WATER USE AND WASTE CHARACTERIZATION
Water is used in various ways throughout the timber products
processing industry and a variety of waste waters result. This
section describes the water usage and characterizes the waste
waters associated with the subcategories identified in Section
IV. For each subcategory discussed herein, a model is developed.
It should be noted that the. water usage and waste water
characteristics described for each operation, unless otherwise
specified, are descriptive of that particular operation. Various
unit operations may be employed in conjunction with other
operations and the resulting waste water characteristics are
essentially a weighted average of those of the unit operations.
For example, prior to the fabrication of wirebound crates, a
veneering operation may be involved. The veneering operation, in
turn, could have associated with it bark removal operations and
log pond storage. The waste stream resulting from the complex
would be a combination of the waste streams from each of the unit
operations.
A model operation is developed below for each of the operations
or combinations of operations discussed in Sections III and IV of
this document. As discussed earlier, the variety of operations
conducted in this segment of the timber products processing
industry are numerous. Consideration of the process water volume
requirements, the process waste water quality, and the
practicability of reuse and disposal techniques results in the
conclusion that so called model operations can be described, not
specific to each and every variation included in this portion,
but applicable to the operations being considered in this
document. This approach is appropriate to the purpose of
developing the control and treatment technologies (Section VII)
and the presentation of cost information (Section VIII).
STORAGE OF LOGS IN ESTUARIES^ IMPOUNDMENTS, RIVERS, AND
TRANSPORTATION OF LOGS IN WATER
The quantity of materials contributed to the water by logs in
open water storage and transportation is dependent on the
leaching rate of substances from the logs which in turn is
dependent on such factors as the residence time of logs in water,
log species, and quality of water. For example, in a laboratory
study, Graham and Schaumburg showed that the leaching of
pollutants from logs is rapid initially but decreases with time.
They also showed that more pollutants were leached from Ponderosa
pine than Douglas fir logs and that more pollutants are leached
from logs suspended in fresh water than from those suspended in
saline waters.
Log storage in open waters occurs primarily in the northwestern
U. S. The primary concern about such storage has involved the
aesthetics of floating bark. Several investigations have been
87
-------
addressed to the problem of bark loss and its eventual deposition
site. The results of the studies all point to the fact that most
of the dislodging of bark from logs occurs at the dump site where
the violent entry into the water is accompanied by the abrasive
action of the logs rubbing against one another. The logs are
usually allowed to free-fall into the water from distances
ranging from a meter or so up to six or more meters, the greater
falls occuring when dumping into tidal waters is done at low
tide.
The work at Oregon State University by Graham under the direction
of Schaumburg on the leaching of pollutants from logs has led to
the formulation of equations characterizing the leaching. The
equation originating from the work of Graham and Schaumburg with
modification by Williamson and Schaumburg is of the form:
T = (1-x) (D) (Ac)
where :
(X) (C) (Ac) + fl (B-D) Ae
T = total pollutional contribution from field logs (grams)
B = grams leached from test log (ends unaltered, w/bark)
sq m of cylindrical area
C = grams leached from test log (ends sealedf w/bark)
sq m of cylindrical area
D = grams leached from test log (ends sealed, w/o barkl
sq m of cylindrical area
Ae = total submerged end area of field logs (sq m)
Ac = total submerged cylindrical area of field logs (sqm)
x = fraction of bark missing from field logs
f 1 = cylindrical area of test log
end area of test log
Typical calculations using this equation for a 20 hectare (50
acre) raft of Ponderosa pine that has a free flowing water
profile and a log storage time of 30 days, yield a COD
combination of 320 kg/day (700 Ib/day) and a BOD contribution of
150 kg/day (320 Ib/day) .
Similar calculations performed for logs stored on a fresh water
reservoir with a volume of about 2.4 x 10s cu m (8.7 x 106 cu ft)
and an average flow of 79.1 cu m/min (46. 5 cfs) yield an average
detention time of 52 hours. Ten measurements of water quality
were made over a three day period of both the influent and
effluent from the reservoir. The average value and the standard
deviation for each of the measured parameters are shown in Table
10. The calculated results are also shown. It can be seen from
this study that the expected and observed changes in water
quality through the reservoirs are extremely small in terms of
concentration. It can also be seen that the predicted change is
always less than the observed change. This is probably because
of the fact that the equation does not take into account the
contribution of the benthic deposits to the water quality.
88
-------
TABLE 10 BOD, COD, FBI AND TOC IN INFLOW AND OUTFLOW
FROM LOG STORAGE RESERVOIR NUMBER 74
Pollution
Index
BOD
COD
PBI1
TOC
CO
CO
±nt±ow wean
Concentration
mg/1
0.25+0.13
8.7+ 3.7
1.6+ 0.83
3.7+ 0.95
Uuttlow Mean
Concentration
mg/1
1.25+ 0.55
10.0+ 4.1
1.8+ 0.54
3.9+ 1.87
Measured
mg/1
1.0
1.3
0.2
0.2
Increase
?
kg/ day
110
150
20
1120
Predicted
mg/1
0.02
0.07
0.16
0.03
Increase
kg/day
2
8
18
' 4
PBI -Pearl Benson Index is expressed as ppra SSL - Spent Sulfite Liquor (10% by weight)
2kg/day based on a flow of 79.1 cu m/min (30mgd)
-------
In addition, the variability of the measured parameters is such
that the standard deviation is nearly half the value of the
parameters for all measured parameters. Limited field
applicability of the equation is, therefore, indicated. Similar
results are reported by Williamson and Schaumburg for other
impoundments studied. The evaluation of the equation by
Williamson and Schaumburg when applied to estuarine analyses
showed that the maximum change in any of the water quality
parameters studied would be less than 1.0 mg/1. Consequently,
field studies were not conducted in this study because it was
surmised that the variability of the water quality resulting from
tidal recycles would far exceed these differences.
Samples were collected in this study in both the Little Deschutes
River and the Deschutes River in Oregon above and below log
impoundments. The results of the analyses of these samples
showed that it was virtually impossible by water quality
measurements to determine the degradation in water caused by the
logs. Some of the downstream samples were higher than the
upstream samples and some were lower, but in both cases the
measurable effect was too low to be considered significant. This
observation agreed with the work of Williamson and Shaumburg.
The waters above and below four large log rafts were measured on
estuaries at Astoria, and at Goose Bay. Three of the four rafts
sampled showed that the concentration of pollutants increased
from the downstream end of the raft to the upstream end, while
the third raft sampled showed an increase in concentration in the
expected direction, from upstream to downstream. Two samples
collected on the Columbia River at Longview, Washington, showed
the same reverse trend. No attempt was made to determine the
variability of the measured parameters because of the magnitude
of the sampling that would have been required.
The data collected by Williamson and Schaumburg and also that
collected in this study illustrate that it is not possible to
readily determine the change in water quality of an impoundment
because of log storage on the impoundment. Without that
capability, it is not possible to reliably predict or measure the
pollutional contribution of the logs to the storage waters. The
effect of easy let-down devices in reducing the amount of
floating bark released to the water is evident from visual
observations, but no further studies were performed to
quantitatively evaluate this. No typical waste water can be
characterized because it is not currently possible to reliably
measure a waste water characteristic that can be attributed
solely to the logs in the water.
90
-------
Wet Storage
The following discussion is divided into three portions,
identified as mill ponds, log ponds and wet decking. The
division, particularly mill ponds and log ponds, may be
considered somewhat artificial. However, this division provides
an opportunity to discuss potential differences in water use and
waste characterization.
MILL PONDS
Mill ponds are those man-made water impoundments used primarily
for sorting logs and feeding them into a plant. Mill ponds are
usually less than one ha (2.5 ac) in size and usually are
typified by low flow rates and short log residence time.
Two of the four ponds reported in a study by Haufbur are typical
mill ponds (Table 11). Ponds C and D are small ponds and the
average storage time is two weeks and one week, respectively.
The relatively high flow of 25 Ips (UOO gpm) through pond C
causes low concentrations of pollutants, whereas the lower flow
of one liter per second (16 gpm) through pond D causes higher
concentrations of pollutants. Pond B in Table 11 would qualify
as a mill pond because of the short residence time of the logs
and because of the high concentration of pollutants, even though
the pond is 8 ha (20 ac) in size. There would have to be an
intense amount of activity occurring on a 8 ha (20 ac) pond in
order to exchange 80 percent of the logs in one week. Pond A is
a typical log pond, in that the area of the pond is large and the
storage time in the pond is long. Because there is no outflow,
the concentration of pollutants is not as low as Pond C, but not
nearly as high as Pond B and D.
Another typical pond is that identified as Pond 04 (Table 12).
It is only about one ha (2.5 ac) in size and the detention time
of logs in the pond is only about three hours. The activity on
the pond is sufficiently high that suspended solids of 579 mg/1
are reported. Other parameters such as COD and BOD are low
because the high flow rate washes the pollutants from the pond.
McHugh, Miller, and Olson collected a large quantity of water
quality data while studying mosquitoes in log ponds. Some of
those data are listed in Table 13 along with the areas of the log
ponds as supplied by the Oregon Department of Ecology. In
addition, data supplied from various sources are list in Table
13.
Grab samples were collected during this study from several ponds
in Oregon and Washington and analyzed for several parameters.
Based on the distinctions mentioned above, some of these ponds
were classified as mill ponds and the values of the measured
parameters are listed in Table 14.
91
-------
TABLE 11
LOG POND DATA
Physical Character!sties of Log Ponds Studied
Surface
Area
Pond Hectares
A -30.5
CO
CO
B 8.1
C .1
D 1.2
Average
Depth,
Meters
2.4
1.8-2.4
3.7
1.2-1.5
Age of
Pond,
Years
11
14
19
39
Type of
Logs
Stored
Douglas
fir
Douglas
fir
85% Pon-
derosa
pine
15% Doug-
las fir
Over 90%
Pondero-
sa pine
Length
of
Storage
1-3 yrs.
80% of logs
about one
week
Two weeks
One week
Water
Source
Stream
Wells
Stream
Springs:
Irriga-
tion
ditch
Remarks
Non-overflowing except during
high runoff periods. Sanitary
wastes dumped Into pond.
Non-overflowing except during
high runoff periods. Sanitary
and glue wastes from plywood
plant dumped Into pond.
Overflowing at about 25 I/sec.
Overflowing at about .0 I/sec.
-------
TABLE 11
LOG POND DATA (Cont'd)
CD
Chemical Characteristics of Log Ponds Studied
Pond A
Point
1
2
3
4
4-B
5
TS,
mg/la/
254
253
230
238
39.1
260
Vs
59
53
49
53
46
56
SS,
mg/1
43
38
27
B4
2.1
35
DO,
mg/1
0.1
0.1
0.4
0.2
0.2
Temp,
°C
22
22
22
22
22
COD, BOD20,
pH mg/1 mgTT
6.9 IJo 48
116
104
116
100
116
BODS BOD5. k, N,b/ NOl-N.c/
mg/T COD day-r.i mg/1 mg/1
29 0.25 0.08 2.4 0.6
P04, PBI
mq/l mg/1
0.5 175
a/ mg/1 - milligrams per liter = ppm
b/ N - total kjeldahl nitrogen (ammonia plus organic nitrogen)
c/ NOS^-N - nitrate nitrogen
4-B = bottom sample taken at point 4
-------
TABLE 11
LOG POND DATA (Cont'd)
Pond B
CO
JT
Point
1
2
3-B
4
5
6
TS,
mg/1
747
724
776
720
723
755
VS
%
55
63
60
61
57
56
SS,
mg/1
180
162
266
234
248
256
DO,
mg/1
0.3
0.2
0.0
0.2
0.3
0.1
Temp,
°C
2X.5
21.5
21
22
22
22
COD, BOD20 BOD5, BOffi k, N, N03-N, P04,
pH mg/1 mgTT mgTI C~J& day-^ mg/1 mg/1 mgTl
7.1 496 167 54 0.11 0.03 110.4 1.5 :.1.2
7 a 484
504
488
488
504
PBI,
ma/1
545
3-B = bottom sample taken at point 3
-------
en
EAELE 11
LOG POND BAT& (Cont'd)
Pond C
Point
1
2
3
4
dfrozen
Pond D
Point
l
2-B
3
4
TS .
mg/1
352
356
360
352
VS
30
33
32
30
ss,
mg/1
d
d
d
4
samples— suspended
TS
mg/1
550
580
530
606
Vs
40
50
44
46
DO,
1.5
1.7
2.0
Temp,
°C
23
23 7
23
sol Ids tests
SS, DO,
mg/1 mg/1
d
d
d
122
0.4
0.2
0.5
0.7
Temp,
°C
21
20.5
21
21.5 7
COD BOD20 BOD 5, BOD5 k, N,
pH mg/1 mg/T mg/1 COD day-1 mg/1
20
.5 24 10 6 0.25 0.08 1
26
22
not run
COD, BOD20, BOD 5, BOD5 k, N,
pH mg/1 mg?T mg/T COD day- 1 mg/1
312
316
3 0
.4 353 116 68 O.i9 0.08 4.9
N03-N, P04, PBI
mg/1 mgTl mg/1
O.i O.i 35
N03-N, P04, PBI
mg/1 mgTl mg/1
0.7 2.0 338
2-B = bottom sample taken at point 2
-------
TABLE 12
WINTER CHARACTERISTICS OF OREGON LOG PONDS?
PART B: PHYSICAL CHARACTERISTICS (Cont'd)
OD
CD
Pond
01
02
03
04
Surface
Area
(Hectares)
23
17
23
1.2
Average
Depth Volume
(Meters) (Cu.M)
l .4
1.2
1.5
1.8
314,912
207,039
345,192
22,937
Type of Log
65%
100%
65%
35%
40%
Doug.
Doug.
Doug.
fir
fir
fir
Log
Deten tlon
60
126
44
Days
Days
Days
Water
Source
Another
Pond
Reservoir
Hemlock
Doug.
fir
3
hours
Creek
Remarks and
Approximate Eff.
Overflow 1n Nov. to Mar. =
about i, 635 Cu. M/Day
Overflow 1n Nov. to Mar. »
about 1,643 Cu. M/Day
Overflow 1n Nov. to Mar. «
about 1,635 Cu. M/Day
Impounded creek overflowing
60% Hemlock
Nov. to Mar. = about 489,000
Cu. M/Day
*Based on Environmental Science and Engineering, Inc. sampling from March 2 to March 6, ]973.
-------
TABLE 12
WINTER CHARACTERISTICS OF OREGON LOG POND*
PART A: CHEMICAL CHARACTERISTICS
CD
Pond
01
02
Q3
04
06
48
BOD5
2
3
5
10
7
3
COD
47
67
57
64
46
78
DS
69
130
81
90
120
271
SS
11
21
31
579
42
26
TS
80
151
112
669
162
297
Turb.
8
6
12
40
28
4
Phenols
0.03
O.Ol
0.03
0.03
0.08
0.06
Color
14
9
18
9
12
13
Kjld-N
1.40
1.33
2.30
0.34
2.82
0,45
T-P04.-P
0,02
0.02
0.02
0.02
0.025
0.02
Note: Turbidity in JTU: color 1n Pt.-Cobalt units; all others 1n mg/1.
*Based on Environmental Science and Engineering, Inc. sampling from March 2 to March 6, 1973.
-------
TOBTE 13
LITERATBKE DMA FOR PCNDS
Temp.
Color
COO
f!IOT
fcOD/COL'
03
04
0?
01
05
06
07
08
09
10
11
12
13
14
15
16
17
13
19
20
21
22
23
24
25
26
27
23
29
30
31
32
33
34
35
36
37
33
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
69
70
69
70
69
70
69
70
69
70
69
70
49
70
69
70
69
70
69
70
69
70
69
70
69
70
69
70
69
70
69
40073
40073
40073
40073
40073
40073
70072
70072
70072
70072
62860
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
50873
52173
21373
21373
22073
22073
22773
22773
30673
30673
31373
31373
32073
32073
32773
32773
40373
40373
41073
41073
41773
41773
42473
42473
50173
50173
50873
50873
51573
51573
60573
60573
71073
71073
91973
-
6.9
7.1
7.5
7.4
6.5
5.0
6.5
5.8
6.9
6.3
7.1
7.4
7.1
6.9
7.0
5.8
6.4
6.4
6.4
5.5
7.4
4.9
6.7
6.9
6.3
6.3
6.4
(..t
7.0
6.2
5.3
6.2
4.8
6.3
7.3
9.5
5.9
6.7
7.8
7.0
6.1
7.0
6.7
6.3
7.8
5.8
6.0
6.5
5.5
5.8
6.2
6.6
7.4
6.0
6.3
6.4
6.5
6.6
6.3
5.6
6.S
6.4
7.1
7.1
6.4
6.4
6.0
6.2
6.3
6.6
6.3
6.4
6.3
6.6
7.6
6.9
6.5
6.5
6.2
6.3
6.6
6.7
6.2
6.5
7.2
8.2
6.3
6.4
6.4
7.1
6.6
- 6.9
6.1
6.2
-
22.0
21.5
23.0
21.5
.
.
_
_
_
.
.
,
_
_
_
_
_
.
.
.
.
_
.
_
_
_
_
_
-
_
_
_
.
-
-
.
-
-
-
.
.
_
_
.
.
-
-
-
.
-
-
-
.
-
-
-
-
-
-
-
.
_
37.0
38.0
52.0
56.0
44.0
52.0
44.0
43.0
46.0
45.0
48.0
51.0
51.0
50.0
50.0
53.0
53.0
58.0
52.0
53.0
54.0
60.0
57.0
64.0
58.0
58.0
64.0
76.0
49.0
71.0
73.0
77.0
-
0.1
0.3
1.5
0.7
,
.
_
_
_
.
_
_
.
_
_
.
.
-
,
.
_
_
.
-
.
_
_
_
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
3.7
1.4
2.6
1.8
1.3
0.0
1.5
0.1
2.1
0.5
0.0
1.8
0 0
olo
0.0
0.5
0.0
3.7
0.9
1.0
0.0
3.4
0.0
0.9
0.0
5.8
0-0
0.0
_
-
18.0
9.0
9.0
14.0
23.0
13.0
-
-
-
-
62.0
100.0
100.0
100.0
75.0
75.0
125.0
25.0
25.0
25.0
150.0
125.0
100.0
25.0
50.0
50.0
50.0
50.0
50.0
150.0
500.0
100.0
50.0
50.0
50.0
25.0
150.0
25.0
100.0
50.0
40.0
20.0
150.0
200.0
40.0
15.0
100.0
50.0
30.0
200.0
100.0
50.0
200.0
25.0
50.0
50.0
200.0
-
175.0
50.0
25.0
20.0
50.0
25.0
50.0
150.0
-
-
120.0
75.0
220.0
140.0
200.0
120.0
200.0
120.0
220.0
140.0
200.0
140.0
130.0
150.0
100.0
150.0
100.0
100.0
140.0
120.0
100.0
125.0
120.0
160.0
100.0
120.0
300.0
300. n
175.0
175.0
450.0
250.0
12.0
dO.O
b.O
8.0
13.0
2C.O
_
.
-
.
7.0
44.0
7.0
11.0
8.0
20.0
10.0
6.0
7.0
8.0
16.0
32.0
34.0
7.0
7.0
50.0
9.0
42.0
12.0
19.0
10.0
10.0
9.0
14. "i
9.0
8.0
23.0
7.0
24.0
12.0
7.0
4.0
23.0
40.0
8.0
8.0
50.0
12.0
8.0
56.0
8.0
8.0
160.0
16.0
14.0
56.0
7.0
-
43.0
6.0
8.0
6.5
25.0
7.0
6.0
7.0
60.0
90.0
112.0
76.0
28.0
26.0
26.0
22.0
38.0
21.0
92.0
34.0
39.0
15.0
74.0
62.0
520.0
570.0
155.0
128.0
84.0
80.0
360.0
230.0
34.0
23.0
68.0
76.0
255.0
190.0
114.0
84.0
150.0
130.0
5.0
10.0
3.0
2.0
33G.O
6.0
29.0
54.0
6.0
68.0
_
_
_
.
_
_
_
.
.
.
,
.
.
_
.
_
_
_
_
_
_
.
_
_
-
-
.
-
-
-
-
-
-
-
-
-
-
.
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
26.0
46.0
34.0
17.0
41.0
29.0
19.0
24.0
31.0
20.0
39.0
36.0-
37.0
22.0
43.0
46.0
20.0
27.0
23.0
20.0
29.0
19.0
24.0
23.0
20.0
27.0
21.0
24.0
24.0
19.0
18.0
41.0
17.0
11.0
57.0
64.0
67.0
47.0
-J57.0
65.0
11G.O
504.0
24.0
353.0
43.0
417.0
93.0
351.0
121.0
105.0
eo.o
48.0
52.0
42.0
68.0
161.0
200.0
11.0
40.0
422.0
31.0
681.0
209.0
300.0
434.0
62.0
9.0
144.0
83.0
67.0
676.0
52.0
713.0
144.0
47.0
11.0
187.0
600.0
82.0
21.0
228.0
4.0
21.0
173.0
117.0
106.0
431.0
112.0
202.0
802.0
84.0
204.0
-
37.0
15.0
38.0
225.0
22.0
37.0
188.0
164.0
118.0
-
_
_
-
-
.
- .
-
-
-
-
-
"
_
.
.
_
_
_
.
_
.
.
.
.
-
-
-
.
.
.
107.0
0.02
0.02
0.02
0.02
0.05
0.02
0.50
1.20
0.10
2.00
0.03
O.lfi
0.12
0.37
0.06
0.18
0.24
0.10
0.02
0.02
0.06
0-29
3.36
0.0
0.06
0.84
0.14
0.60
0.44
0.0
0.01
0.0
0.04
0.10
0.04
0.0
0.49
1.02
0.50
2.66
0.05
0.0
0.15
3.00
3.00
0.37
0.77
0.06
0.10
0.41
0.14
0.10
0.0
_
0.76
0.24
0.15
0.76
0.29
0.0
0.10
0.01
0.03
0.10
0-0
0.04
0.03
_
_
_
_
.
_
_
_
_
_
_
.
.
.
_
.
.
_
.
_
_
_
_
.
,
_
^
_
.
2.20
2.30
0.34
1.33
1.40
0.05
1.82
2.40
10.40
1.00
4.90
0.13
7.67
9.60
5.50
5.40
-
-
5.10
6.04
2.68
3.22
0.21
11.62
-
0.19
4.57
0.22
9.95
-
-
-
0.95
' -
16.10
7.01
10.58
8.86
7.30
_
3.55
_
2.59
0.48
4.51
1.90
5.44
9.19
4.32
8.57
3.05
2.61
0.17
0.22
1.49
0.38
0.64
4.00
0.12
0.08
.
_
.
.
.
_
"
_
_
_
_
_
_
_
_
_
.
_
.
.
.
.
_
,
_
O.f.0
0.09
0.16
0.04
0.04
0.35
0.09
0.25
0.11
0.25
0.19
47.0
391.0
290.0
347.0
261.0
291.0
257.0
234.0
300.0
85.0
138.0
222.0
320.0
33.0
76.0
506.0
117.0
658.0
340.0
502.0
481.0
_ • 116.0
82.0
260.0
345.0
102.0
422.0
123.0
255.0
237.0
247.0
116.0
244.0
669.0
417.0
393.0
455.0
97.0
76.0
473.0
185.0
146.0
1055.0
'130.0
268.0
805.0
150.0
23876.0
74.0
60.0
82.0
2097.0
68.0
66.0
154.0
0.16 222.0
0.39 225.0
"
_
_
_
_
_
.
_
-•
.
.
.
-
_
_
-
.
-
-
-
-
-
-
-
-
-
-
-
-
TUI^S Area
57.00
. 3.00
4?.or)
57.00
95.0
71.0
88.0
23.0
72.0
35.0
60.0
3.0
35.0
35.0
49.0
89.0
64.0
79.0
42.0
21.0
12.0
35.0
94.0
35.0
29.0
26.0
26.0
19.0
25.0
32.0
16.0
26.00
20.00
2.50
3.00
6.00
0.50
0.70
1.00
0.75
3.00
3.00
1.50
1.50
0.74
1.00
0.60
2.50
0.50
1.00
2.50
2.00
0.70
5.00
0.50
4.00
0.60
2.50
1.50
0.30
2.00
1.00
0.70
0.50
100.00
0.10
1.50
4.00
. 0.70
0.25
1.50
0.30
4.00
6.00
0.50
0.25
0.50
0.50
-------
TABLE 14
CHARACTERIZATION OF MILL PONDS
Water
CO
CO
Pond
44
44
72
28
04
23
23
73
Color
86
124
433
171
9
571
476
117
Jurbidity
20
67
36
4
40
15
9
304
BOD5
59
55.9
66
44
10
50
40
-
COD
98
84.5
221.2
53
64
301
262
121.6
P04
2.0
3.45
5.44
1.80
0.02
6.49
7.18
1.84
NT
1.95
1.86
4.91
2.42
0.34
5.54
4.57
2.18
TS
429
448
446
153
669
350
298
138
SS
8
30
199
31
579
68
66
103
TDS
421
418
247
121
40
282
232
35
TVS
112
141
216
70
-
.258
194
75
VSS
0
11
129
25
-
37
142
52
VDS
112
130
87
45
-
221
152
23
Phenols
39.3
—
98.7
9.4
22.0
5.4
11.4
2.6
Flow
(Cu rn/day)
6,170
6,170
0
0
488,265
0
0
Production
(Cu m/day)
0.39 '
0.39
0.65
0.06
0.63
0.42
0.42
0.37
Pond Area
(Hectares)
1.2
1.2
0.2
1.2
0.2
1.2
0.2
1.2
-------
several observed trends have been previously noted in making the
distinction between log ponds and mill ponds* These include the
small pond size and the great amount of activity on the mill pond
as compared to the log pond. Chemical parameters tend to support
this distinction as shown in Tables 11, 12, and 13, in that total
solids, COD, BOD, nitrogen, and phosphate concentrations in the
mill pond tend to be higher than those in the log ponds.
Regression analysis was conducted for selected parameters for the
ponds of less than one ha (three ac) in Table 13 and for the six
ponds in Table 14. The correlation coefficient (r), the slope
(m), and the intercept (b) of the line of best fit for the linear
regression analysis are shown in Table 15. More than 40 data
points were used in all the regressions from Table 13 with the
exception of the COD-BOD relation where only 11 observations were
available. The parameters for which significant correlation
occurred were COD-TS
-------
15
DATA CORRELATIONS FOR MILL PONDS
PART A (McHugh, et al. Data)
Independent Variable
COD
COD
COD
COD
COD
POi
BOD
COD
PART B (Six Ponds, Thi
COD
COD
COD
COD
COD
P04
BOD
COD
COD
Dependent Variable
N!
Color
P04
TS
Turbidity
NT
NT
BOD
s Study)
NT
Color
POi
TS
Turbidity
NT
N!
BOD
ss
r*
0.487
0.355
0.224
0.854
0.527
0.641
0.620
0.838
0.903,
0.935
0.943
-0.036
-0.113
0.964
0.687
0.433
-0.231
m
0.0102
04479
0.00105
0.7922
0.0668
2.9715
0.0777
0.1307
0.0179
2.063
0.0259
-0.078
-0.139
0.697
0.0651
0.090
-0.530
b
2.936
594J2
0.3536
£23.556
7.756
3.147
0.6507
4.41,6
0.33,6
-59.94
-0.487
372.38
92.77
0.633
0.0245
31.782
239.97
Dependent Variable = (m) (Independent Variable) + b
101
-------
to the physical parameters of the pond. The fact that the
suspended fraction of the mill pond waters does not correlate
well with any of the soluble parameters indicates that the
suspended fraction is not related to the activity on the pond in
the same fashion as the soluble fraction. It was not possible to
obtain a good correlation of the suspended fraction with any
rational combination of the physical parameters. This may
indicate that the suspended fraction is highly dependent on the
specific conditions existing in the particular pond with respect
to the amount that the bottom gravel and muds are agitated, while
the soluble fraction is primarily a function of the amount of
materials leaching directly from the logs.
The poor correlation of BOD and COD concentrations further
evidences the low reliability that should be placed on BOD for
materials leached from woods and barks. The highly variable
behavior of the BOD/COD ratio for uncooked leachates was
evidenced throughout the study.
The characteristics of the effluent from a mill pond, in the
event that there is a discharge, is highly dependent on the
number of logs going across the pond per unit time and is less
dependent on the area and hydraulic flow through the pond. There
is often a discharge from the mill pond because of the function
of the mill pond in the timber products industry. The mill pond
is used to feed the logs into the mill, and usually to sort the
logs before they go to the mills. Because most mill machinery is
set up to accomodate only a small water level fluctuation, it is
necessary to maintain the pond near full or completely full
throughout the year. For this reason, even a non-flowing pond
will overflow during a period of natural precipitation. Some of
the ponds are allowed to overflow continually, but with greater
overflow occurring during periods of precipitation. During
periods of low precipitation, water is added to the pond to make
up for evaporative losses. Hence, the mill pond is always full
and the discharge may be continuous or intermittent.
It is difficult to describe a single waste stream, or even a
waste stream . that is characteristic of a mill pond.
Consequently, the data in Table 16 are for a hypothetical mill
pond representative of a mill pond with a moderate flow and log
loading, and a large area.
LOG PONDS
Several laboratory studies have been performed prior to this
study, but have limited value in discussing log ponds. However,
the data developed in the studies are valuable in establishing
trends that can be expected for pollutants in log ponds. One
that is particularly applicable is the study conducted by Graham
on the leaching of pollutants from logs submerged in tanks with
suppressed biological activity. The study showed that COD, TOC,
FBI, and TVS of the water increased at a rapid rate initially and
then tended to reach a maximum concentration at detention times
greater than UO days. In addition, it was observed that if the
102
-------
TABLE 16
TYPCIAL WASTE STREAM FROM A MILL POND
Parameter Value
Hydraulic flow, cu m/day 3,800
Log loading, cu m/day 115
Area, hectares
Calculated Parameters
COD (rag/1) 68
Color (units) 80
NT 1.53
1;.27
Estimated Parameters
BOD5. Cmg/1) 14
Turbidity (JTU) 20
Total Solids (mg/1) 250
Suspended Solids (mg/1) 50
Ida
-------
log that had been leached to an apparent maximum concentration in
the surrounding water was then removed from that water and then
placed in fresh water, the concentration of leachates increased
in the fresh water in a fashion similar to that in the original
water. This indicated that the leaching rate of materials from
the log is a function of the concentration of the leached
materials in the surrounding waters. It was also found that the
bark inhibits the initial loss of soluble organic matter from the
logs and contributes most of the color producing substances. It
was also found that Ponderosa pine logs contribute higher
concentrations of leachates than Douglas Fir logs.
In a study by Benedict, bark was submerged in water and the
concentration of leachates in the water was measured with time.
Just as in the log study, maximum concentrations were reached
after 40 to 60 days, but the concentration of leachates was
considerably higher. The age of the bark was found to be an
important variable, i.e., the older bark yielded less leachates
than the younger. Similar work by Asano and Towlerton involved
the study of leachates from submerged wood chips. Once again,
the plateau value of concentration was obtained, but after only
20 to 30 hours of agitation of the sample. The concentration of
leachates in the surrounding water was found to be dependent on
the concentration of wood chips in the water. The color of the
supporting water was found to increase to 3,000 to 4,000 standard
color units, whereas the color of the water surrounding the bark
in the Benedict study was found to increase to 7,000 to 8,000
units. This is in support of the observations by Graham that
most of the color from the logs came from the bark. A different
study by Spoul and Sharpe on bark tends to support the
observations in the three previously mentioned studies, but the
experimental conditions were different and direct comparison is
not possible.
Pond A listed in Table 11 is a good example of a log pond and,
even though Pond B is large enough to conform to the area
associated with the log ponds, the number of logs that move
across the pond per day is so high that Pond B should be
classified as a mill pond. The listing of literature data in
Table 13 shows that only eight of the ponds in the list have
areas large enough to be classified as log ponds. Two of these
ponds are the same as Pond A and B listed in Table 11, one of
which is not a log pond even though its size is substantial.
Three of the ponds were sampled only once in the winter and two
of the ponds were sampled only once in the summer. Only one pond
was sampled more than once and the data were rather incomplete.
For these reasons, it was determined that a more comprehensive
study should be performed on log ponds in order that adequate
characterization could result.
Three log ponds were selected for study. The selection was based
on the size and physical characteristics of the ponds, and the
fact that previous data had been collected on these particular
ponds. Log Pond 01 (Figure 23) was chosen because there is no
mill or plant on its shores or discharging into it. Log Pond 02
-------
o
or
TO LOG
POND-02
LOG LOAOIN
X - PROFILE SAMPLING POINTS
[7) - SURFACE SAMPLING POINTS
FIGURE 23 LOG POND 01
-------
o
LOG
DUMP
POND INF-
PLANT EFP
INFLUENT
(SUBMERGED)
X - PROFILE SAMPLING POINTS
X) - SURFACE SAMPLING POINTS
FIGURE 24 LOG POND 02
-------
EFFLUENT
WEIR
O
DUMPING
AREA,
PARTIALLY
SUBMERGED
LOG DECK
POND
MFLUENT
X - PROFILE SAMPLING POINTS
3) - SURFACE SAMPLING POINTS
FIGURE 25 LOG POND 03
-------
TABLE 17
AVERAGE VALUE AND 95 PERCENT CONFIDENCE
INTERVAL FOR VARIOUS XrawftHg ^ iaf
POND Ul
COLOR TURB. BOD5 COD P0
I.rfluent
(N = 5)
*[_ TS. • TSS IH! TVS TVSS TVDS PHENOLS
11.59+5.58 1.58+1.13 5.98+7.43 13.8+7.44 0.59+0.28 3.75+5.58 46.39+31.88 27+28.89 19.4+6.7 20.60+14.09 11.40+11.74 9.20+10.56 12.32+7.40
Effluent
Week 1
(H - H)
Effluent
Week 2
(N-7)
Effluent
Week 3
{N = 3)
Effluent
Total
(N = 24)
121.35+2.14 3.57+0.43 18.68+3.00 58.95+5.76 1.01+0.25 4.03+2.25 113.5+27.9 32.5+13.3 81.0+23.5 60.57+13.74 15.86+7.44 44.71+9.92 16.18+8.09
122.70+7.90 4.43+1.39 19,04+11.57 57.8+2.5 0.92+0,29 1.91+0.39 151.57i?7.33 33.14+25.47 119.28+_67,50 77.86+18.77 14,28+12.01 64.71+16.91 10.91+7.22
103.66+^24.53 4+4.99 22.13+29.35 56.73i5.77 1.04+0.56 1.91+0.69 77+13.1? 10.6+27.3 66.3+10.1 62.3+23.8 2.60+5.16 59.6+21.13 10.89+5.73
120.38+4.37 3.88+0.SO 19.22+3.52 56,89+.3.46 0.99+0.17 3.15+1.32 120.04+25.78 29.96+9.99 90.33+20.79 65.83+9,43 13.79+5.30 52.42+7.76 13.57+4.73
o
GO
-------
TABLE 19
AVERAGE VALUE AND 95 PERCENT CONFIDENCE
INTERVAL FOR VARIOUS PARAMETERS FOR LOG
POND 02
TSS IDS TVS TV5S
TVDS PHENOLS
Influent
(N = 4)
COLQR__ TURBIDITY BODs COD P04 NT Ts
135.75+23.96 13+3.91 23.17+3.50 108.92+22.02 1.52+0.57 2.73+0.54 271.5+93.84 58+69.88 188.5+41.3 104.75+40.28 23.25+40.09 81.5+15.24 18.80+31.23
Effluent 144.5*31.77 8.57+1.12 28.58+9.96 96,21+6.11 1.25+0.43 4.69+2.48 223.43+16.44 36,78+18.25 186+22.27 101.78+11.94 19.5+11.9 82.28+12.98 24.70+12.33
Week 1
(N " 14)
Effluent 138.14+9.20 10.43+1.91 21.34+9.32 86.88+4.18 1.09+0.12 2.59+0.49 269.86+39.49 45.71+48.4 223.86+59.49 107.28+33.38 22.86+25.99 84.43+20.11 9.33+5.91
Week 2
(N-7)
Effluent 115+11.4 7.66+1.46 19.30+6.28 88.43+10.37 1.17+0.39 2.38+0.47 215.33+77.63 31.6?i91.22 183.67+17.47 118.33+92.0 25.33+92.47 89.67+11.23 16.90+12.45
Week 3 " ~
(N = 3}
Effluent 138.96+18.03 g+p.85 25,31+6.14 92.10+5.01 1.19+0.25 3.77+1.43 l!35.58+25.06 38.75+15.93 196.75+20.01 105.45+11.40 21.21+10.10 83.83+8,63 ig.QO+7.42
Total ' ~
(N =24)
o
CO
-------
TABLE 19
AVERAGE VALUE AND 95 PERCENT CONFIDENCE
INTERVAL FOR VARIOUS PARAMETERS FOR LOG POND 03
COLOR
TURB.
COD
PO,
TS
TSS
TDS
TVS
TVSS
TVDS
PHENOLS
Inf'usr.t
(N •= 3)
Effluent,
Week 1
(M - K)
Effluent
K;ok 2
(X -7)
Effluent
Week 3
(N - 3}
Effluent
Total
3.33+ 7.19
-3.36- 10.52
357.71+ 72.30
285.41-430.01
344.57+ 9.23
335.34-353.fiO
321.0 + 58.52
2S2. 48-379. 52
357.62+ 35.69
321.93-393.31
0. 29*0.43
-0.143). 72
5.00+0.78
4.22^5.78
5.57+0.73
4.8'',~6.30
4.33+3.79
0.54^8.12
5.09+35.69
4.57~5.61
9.27+18.42
-9.15-27.69
33.01+ 7.95
25.06-40.96
35.53+35.07
0.46-70.60
22.10+ 6.88
15.22-28.98
32.37+ 9.46
22.91-4.83
7.73+ 8.99
-1.26^16.72
134.43+ 3.54
130.89^137.97
127.74+ 24.8C
102.90^152.58
126.20+ 31.11
95.09^157.31
133.40+ 6.46
126.94^139.86
0.54+0.69
-0.15^.23
1.66+0.43
1.23~2.09
1.22+0.39
0.83^1.61
1.82+0.65
1.17^.47
1.55+0.27
1.28^1.82
t
1.49+0.52
0.97-2.01
5.64+2.66
2.98"8.30
3.04+0.20
2.84"3.24
2.81*0.04
2.77~2.85
4.50+1.57
2.93"6.07
33.33+ 31.28
2.05- 64.61
149.14+ 24.13
125.01^173.27
143.86+ 31.96
111.90^175.82
130.33+ 27.97
102.36^158.30
145.29+ 15.50
129.79^160.79
14.33+34.85
-20.52-49.18
38.36+22.77
15.59-61.13
39.00+39.25
- 0.25-78.25
24.00+46.09
-22.09^70.09
36.75+15.81
20.94-52.55
19.00+ 13-17
5.83- 32,17
112.21+ 11.08
101.13^123.29
104.86+ 18.65
86.21-123.51
106.33+ 20.27
86.06^126.6
109.33+ 7.70
101.63^117.03
19.67+ 14.85
4.82- 34.52
105.14+ 14.75
90.39^119.89
109.43+ 12.28
97.15-121.71
106.33+ 41.05
65.28^147.38
106.54+ 8.88
97.66^15.42
7.33+22.98
-15.65-30.31
27.14+14.80
12.34-41.94
24.00+21.00
3.00-45.00
16.33+41.78
-23.45-60.11
25.13+ 9.81
15.32-34.94
12.67+ 15.02
-2.35- 27.69
78.00+ 13.02
64. 98r 91.02
85.43+ 16.71
68.72-102.14
88.00+ 2.50
85.50- 90.50
81.42+ 8.34
73.08" 89. 76
9.89+ 9.78
0.11^19.67
37.48+19.25
•18.23-56.73
8.43+ 5.49
2.94^13.92
27.07+62.82
35.75-89.89
28.55+12.85
15.70~41.40
-------
TABLE 20
SURFACE SAMPLE ANALYSES FOR LOG PONDS 01
Sample
Surface No. No.
23
89
±38
Average
2 24
90
139
Average
3 21
91
156
Average
4 22
92
137
Average
pH
6.2
5.9
6.0
6.0
5.9
5.7
5.9
5.8
6.3
5.8
6.4
6.2
6.3
5.7
5.9
6.0
Temp,
°F
17
i 7
I9
1,8
i7
V
23
I9
17
20
30
22
16
i8
22
19
DO
IB
i.4
0.8
1.2
J.6
J.5
i-7
1.6
1.4
2.5
5.9
3.3
1.8
1.9
0.8
1.5
Color
143
119
94
Us
iso
121
198
116
128
124
90
114
131
124
195
117
Turb
5
4
7
5
6
3
6
5
5
5
4
5
8
4
4
5
BODS
14.0
24.5
20.0
19.5
16.0
22.0
17.0
1,8.3
25.5
19.5
18.0
21.0
18.8
3 .5
20.5
23.6
COD
56.6
53.2
59.4
56.4
63.8
57.4
55.4
58.9
52.5
54.6
57.4
54.8
68-7
65.3
65.1
P04
(M9
0.99
1' 1-0"
1.0?
1.26
0.98
1.04
1.09
1.38
0.92
1.3]
1.20
1.30
1.20
1.23
1.24
NT
4.48
1.88
1-92
2.76
4.7i
2.2i
1.76
2.89
3.26
2.03
2.32
2.54
3.96
2.46
2.32
2.91
TS
.85
126
83
98
110
116
73
100
78
23
87
96
83
90
9|
88
TSS
;5
0
28
38
54
35
20
36
6
13
17
12
23,
12
21
19
TDS
70
]6
55
80
56
8]
53
63
72
11.0
70
84
60
78
70
69
TVS
70
70
55
65
72
78
62
71
63
42
67
57
78
64
73
72
TVSS
16
2
1
6
44
34
0
26
3
0
2
5
17
5
3
8
TVDS
54
68
54
59
28
44
62
45
60
32
65
52
61
59
70
63
Phenols
5.0
13.7
19.6
12.8
4.4
14.4
12.9
10.6
12.7
3,2. 3
11. 0
i8.5
I5-6
i8.5
l«-2
-------
TABLE 21
SURFACE SAMPLE ANALYSIS FOR LOG POND 03
ro
Surface No.
1
2
3
4
Sample
No.
31
112
128
Average
35
114
133
Average
33
113
129
Average
36
115
132
Average
JDH_
6.4
6.2
6.2
6.3
6.8
6.3
6.4
6.5
6.8
6.0
6.3
6.4
6.9
6.3
6.1
6.4
Temp
°F
20
24
21
22
19
20
23
21
19
18
18
18
24
22
22
23
DO
2.3
4,0
1.3
2.5
1.8
3.9
1.2
2.3
1.8
1.4
0.9
1.4
3.1
2.0
0.5
1.9
Color
135
119
113
122
124
119
106
116
124
133
107
121
138
131
114
128
Turb
8
7
6
7
7
7
6
7
7
12
12
10
10
11
12
11
BODS
22.0
37.8
18.0
25.9
23.0
44.1
23.7
30.3
23.0
40.1
19.2
27.4
22.4
39.1
21.7
27.7
COD
92.9
79.6
93.1
88.5
95.0
79.5
196.0
123.5
95.0
82.3
95.0
90.8
90.9
82.3
131.5
101.6
P04
0.83
0.88
i.29
1.00
0.91
1.37
1.07
1.12
0.85
1.21
1.29
1.12
1.02
0.91
1.34
1.09
NT
2.72
2.80
2.38
2.63
2.93
2.52
2.06
2.50
2.43
2.32
3.51
2.75
2.20
2.28
2.84
2.44
TS
232
187
203
207
222
188
198
203
222
194
199
205
217
191
212
207
TSS
36
49
13
33
29
65
35
43
29
82
11
41
14
33
19
22
TDS
196
138
190
175
193
123
163
161
193
112
188
164
203
158
193
185
TVS
107
71
140
106
60
64
103
76
60
78
112
83
45
88
99
77
TVSS
22
37
11
23
20
54
5
26
20
51
9
27
8
32
1
14
TVDS
85
34
129
83
40
10
98
49
40
27
103
57
37
56
98
64
Phenols
41.7
11.7
22.9
25.4
28.9
13.3
4.8
15.7
13.9
5.6
30.6
16.7
24.2
9.6
11.9
15.2
-------
TABLE 22
SURFACE SAMPLE ANALYSIS FOR LOG POND 03
CO
Surface No.
l
2
3
4
5
Sample
No.
44
79
.147
Average
48
84
148
Average
45
80
149
Average
46
83
150
Average
47
82
151
Average
pH
5.9
5.9
5.4
5.7
5.9
5.8
5.6
5.8
5.9
5.9
5.5
5.8
5.9
5.8
5.8
5.8
5.9
5.9
5.7
5.8
Temp
°F
20
19
23
21
24
19
26
23
26
22
22
23
25
23
25
24
23
20
25
23
DO
1.4
1.3
1.0
1.2
1.4
1.5
1.2
1.4
2.1
1.9
0.5
1.5
1.5
1.4
0.4
1.1
1.4
1.5
1.2
1.4
Coloi
343
340
342
342
333
365
338
345
348
375
342
355
381
365
324
357
381
375
343
366
P04 NT TS TSS TDS TVS TVSS TVDS Phenols
5 26.5 135.3 0.99 3.26 150 85
5 23.5 117.2 1.26 3.14 241 171
3 23.8 11B.8 1.81 3.40 182 72 110 155
4 24.6 123.8 1.38 3.27 191 109 82 136
6 19.5 133.3 0.93 2.43 145 12 133 97
6 21.5 124.0 0.96 3.41 245 :163 82 135
2 16.5 118.8 1.86 3.17 162 40 022 142
5 19.2 125.4 1.25 3.00 184 72 112 125
65 92 30
70 161 121
60
70
7
62
21
30
28.5
22.0
17.0
22.5
22.0
29.0
17.0
22.7
7 22.5
6 21.5
2 15.5
5 19.8
135.3
119.2
122.8
225.8
135.2
120.0
122.8
.126.0
127.2
124.0
120.8
124.0
0.92
1.17
1.49
,1,19
0.81
1.44
1.59
1.28
0.92
1.17
1.51
1.20
2.77 96
2.56 16.1
3.07 155
2.80 137
2.72 197
2.86 120
3.37 157
2.98 168
2.58 160
2.46 .151
3.11 155
2.72 155
28 68 56
10 151 126
28 127 133
22 115 105
17 180 77
25 195 99
20 157 108
21 .147 195
10 150 115
53 98 98
58 97 ^21
40 115 111
12
22
7
14
2
23
54
26
62
40
95
66
90
73
121
95
8 48
7 119
28 107
14 91
65
77
101
81
113
75
67
85
31.1
9.2
17.5
19.3
26
17
11.0
18.4
23.3
5.2
18.7
15.7
14.4
19.0
19.8
17.7
25,
18,
16,
20.0
-------
TABLE 23
WINTER DATA FOR LOG PONDS 01, 02, AND 03
Date
Color
01
202 110673
205 110673
208 110773
211 110773
214 110873
218 110973
222 111273
Average Values
02
203 110673
206 110673
209 110773
212 110773
215 110873
219 110973
223 111273
Average Values
03
201 110673
204 110673
207 110773
210 110773
213 110873
217 110973
224 111273
Average Values
Observed Flows:
120
138
138
123
123
109
105
122
136
148
140
143
141
118
121
135
295
319
314
302
296
286
290
300
Pond 01
Pond 02
Pond 03
Turbidity BODs COD PQ4 NT TS TSS
70S
TVS
TVSS
4.
7.
15.
6
6
5
7
5
4
5
5
12
10
11
14
6
8
10
8
8
16
6
6
5
4
4
7
6 Cu M/Min
1 Cu M/Min
6 Cu M/Min
20.0
13.0
20.0
14.4
20.0
5.0
10.0
15.0
23.0
23.0
23.6
29.4
4.5
8.0
24.0
19.4
17.0
24.0
15.0
26.6
10.0
15.0
20.0
18.2
63.5
61.9
66.6
62.3
61.2
60.0
63.1
62.7
109.0
103.9
113.7
105.8
91.3
102.7
110.5
105.7
110.9
107.8
109.8
109.4
•109.8
107.4
109.1
109.2
1.6
3.5
2.9
3.2
1.1
0.9
2.0
2.2
1.2
3.0
2.5
1.4
1.3
0.7
1.4
1.6
4.8
4.8
3.8
6.0
2.1
1.8
4.0
4.5
i
1.83
1.80
1.68
2.53
2.54
0.79
1.09 •
1.75
2.18
1.96
2.46
3.68
1.88
1.32
1.57
2.15
4.10
2.73
2.58
2.88
2.98
1.69
1.30
2.61
90
97
63
96
135
76
63
89
225
231
202
235
168
215
201
211
120
138
93
140
136
113
95
119
45
35
8
13
35
4
5
21
62
28
18
68
10
32
19
34
47
50
1
26
42
19
5
27
45
62
55
83
100
72
58
68
163
203
184
167
158
183
182
177
73
88
92
114
94
94
90
92
78
76
60
59
75
54
25
61
115
116
86
102
98
79
88
98
83
100
90
90
89
. 88
72
87
TVDS
38
• 24
8
2
31
0
4
15
52
12
0
50
8
6
12
20
33
40
0
7
18
12
1
\;
40
52
52
57
44
54
21
46
63
103
86
52
90
73
76
78
• 50
60
90
83
71
76
71
76
Phenols
' 0
0
0
139.4
42.3
20.5
22.4
32.1
6.9
2.3
0
50
32.
31.8
13.7
19.6
1.7
2;0
0
87.3
56.1
35.2
16.0.
28.0
-------
TABLE 24
DIURNAL S1UDY ON LOG PONDS 01 AND 02
cn
Pord Location Ph TenilL. DO,
01 Pond-AH Surface 5.8 16° .9
' Middle 5.8 16° .7
Bottom 5.8 15° .5
01 Pcnd-PM Surface 6.0 17° 1.7
Middle 5.9 16° 1.5
Bottom 5.9 15° 1.3
02 Pond-AM Surface 6.1 17° 1.0
Middle 6.0 17° .7
Gotten 6.0 17° .6
02 Pond-PM Surface 6.2 23° 1.9
Middle 6.0 17° 1.0
Bottom 6.0 17° . .7
117
119
119
133
126
126
114
126
124
131
131
5
7
6
6
6
9
5
10
9-
COD poa NT
27.5 51.5 2.05 1.91
23.4 51.5 1.80 2.17
24.5 53.4 1.17 2.30
25.0 54.9 .91 2.14
16.6 54.9 1.09 1,54
22.0 54-.1 1.02 1.74
23.0 S7.1 1.20 2.46
29.5 92.1 1.06 2.37
27.0 84.3 1.11 2.37
29.0 85.4 1.00 2.21
26.0 98.0 1.13 2.43
31.0 86.2 1.23 1,66
Total Total
Total Total Total Volatile Volatile Depth
Total Suspended Dissolved Volatile Suspended Dissolved Phenols Sampling
Solids
75
85
65
90
75
83
186
186
183
198
316
248
Solids
9
13
3
28
3
23
. 16
9
2
15
141
93
Solids
66
72
62
62
67
60
170
177
181
183 •
175
155
Solids
56
77
49
82
67
51
96
79
90
79
121
98
Solids
0
2
0
25
0
12
7
2
2
10
28
36
Solids
56
75
49
57
67
39
89
77
88
69
93
62
mg/1
6.0
2.3
2.3
41.7
13.3
92.5
4.6
2.3
3.7
20.0
15.4
6.2
Point
-
1.7m
-
-
-
-
-
-
2.3m
-
-
_
-------
TABLE 25
DATA FROM LOG PONDS IN THE WASHINGTON
OREGON, IDAHO AREA LOG PONDS
Area
Pond PH Temp. Color Turbidity BODS COD P04 NT TS_ I$S TDS. TVS TVSS TVDS Phenols (Hectares)
71 - - 29 0 7.5 29.7 .90 .87 67 0 67 38 1 38 0.0 70
19 - - 276 26 - 233.2 11.18 7.12 446 53 393 163 0 163 39.3 6
M 72 - - 21 5 21.5 13.7 2.00 3.98 95 8 87 20 0 20 0.0 22
CO 69 6.15 75°F 350 140 14.0 107.0 2.20 0.60 - 24 - - - 0.01 93
01 - - 109 2 13.2 43.1 .40 3.15 112 3 71 45 43 43 - 49.9
02 138 9 25.3 92,1 1.19 3.77 236 39 196 105 21 84 - 52.2
03 - - 354 5 23.1 125.7 1.01 3.01 74 22 90 87 18 69 - 48.9
-------
AVERAGE DEPTH - 1.51 METERS
VOLUHE • 303.97 MILLION LITERS
(ALL DEPTHS SHOWN IN METERS)
FIGURE 26 BOTTOM CONTOURS FOR LOG POND 01
-------
oo
.5 / 1.8 t.6 1.8 I.8
.8 / 2.1 2-3 2-3
2.3 2.3 / 2.4 2.4 \ 2.3
2.S 2.3 2.3 2.1 / 1-8
AVERAGE DEPTH - 2.03 METERS
VOLUME - 428.12 MILLION LITERS
(ALL DEPTHS SHOWN IN METERS)
FIGURE 27 BOTTOM CONTOURS FOR LOG POND 02
-------
-------
18 24 3O 35 40 45 47 52 57
2.0
TEMPERATURE
12 W 24 SO 35 4O 45 47 62 57
PH
« 12 IB 24 3O 35 4O 45 47 52 57
DISSOLVED OXYGEN
FIGURE 29 TEMPERATURE, pH, AND DISSOLVED OXYGEN PROFILES FOR LOG POND 01
120
-------
M 20 26 31 36 41
TEMPERATURE
8 14
STATION NUMBERS
20 26 31 36
41
4fl _ S3_
u 1.5
8 M __ 20 26 31 36 41
DISSOLVED OXYGEN
FIGURE 30 TEMPERATURE, pH, AND DISSOLVED OXYGEN PROFILES FOR LOG POND 01
121
-------
5 9 15 21 27 33 39 45
TEMPERATURE
67
12 R 9 15 ,21 27 33 M 46
39 49 51 67
DISSOLVED OXYGEN
FIGURE 31 TEMPERATURE, pH, AND DISSOLVED OXYGEN PROFILES FOR LOG POND 02
122
-------
STATION NUMBERS
7 ft 17 23 29 55 41 47 83
TEMPERATURE
II 17
STATION NUMBERS
23 29 35
STATION NUM BERS
II 17 23 29 36
59
41 47 53 59
41 47 53 59
DISSOLVED OXYGEN
FIGURE 32 TEMPERATURE, pH, AND DISSOLVED OXYGEN PROFILES FOR LOG POND 02
123
-------
STATION NUMBERS
13 17 24 32
40 47
TEMPERATURE
STATION NUMBERS
J3__ 17 24 K-
4O 47
53
STATION NUMBERS
S 9 !3 IT 24 32 4O 47 53
DISSOLVED OXYGEN
FIGURE 33 TEMPERATURE, pH, AND DISSOLVED OXYGEN PROFILES FOR LOG POND 03
12k
-------
STATION NUMBERS
7 II 15 2£ 30 36 45 51
z.o
TEMPERATURE
STATION NUMBERS
II 15 22 _30 38 4S 51
2.0
PH
15 22 30 38 45 SI
2.0
DISSOLVED OXYGEN
FIGURE 34 TEMPERATURE, pH, AND DISSOLVED OXYGEN PROFILES FOR LOG POND 03
125
-------
(Figure 24) was selected because of the low amount of activity on
the pond (even though the log loading on the pond is high) and
also because the primary influent to the pond is the effluent
from Pond 01 which already contains a moderately high
concentration of pollutants. Log Pond 03 (Figure 25) was chosen
because there was a high amount of activity on one end of the
pond and the pond is a non-overflowing pond during the summer
months. In addition to these reasons, the ponds were in adequate
geographical proximity that all three could be sampled in the
same day and direct comparison of the data was possible.
The three ponds were sampled for three weeks during the summer
and for five days at the beginning of winter. Fourteen effluent
samples were collected during the first week of sampling from
each of the ponds, seven during the second week, and three during
the third week. Three to five influent samples were collected
during the same period. Four or five surface sample sites over
the area of the pond were selected, and one sample from each of
these sites was collected each week. These samples were analyzed
for 12 selected parameters in addition to the field
determinations of pH, Dissolved Oxygen (D.O.) and temperature.
The influent and effluent data summary for the ponds is presented
in Tables 17 through 19. The average value and the 95 percent
confidence range for each of the parameters is presented for the
influent and also for the effluent for each week and totally.
The number of samples comprising the data involved in that
sampling period is also indicated. The surface sample locations
are indicated in Figures 23 through 25 and the corresponding data
for the locations is shown in Tables 20 through 22. The data
from the winter sampling are shown in Table 23.
Sampling sites were established every 200 ft on each of the
ponds. At these sites, the depth was recorded, and the pH,
temperatures, and D.O. were measured at various depths. Bottom
contours for the ponds were established and are shown in Figures
26, 27, and 28. Temperature, pH, and D.O. profiles for the
various lines through the pond are presented in Figures 29
through 34. In addition, a diurnal study was conducted on Log
Pond 01 and also on Log Pond 02. The data for the diurnal
studies are shown in Table 24.
Samples were collected from several other ponds in Oregon,
Washington, and Idaho. These samples were analyzed and the data
are presented in Table 25.
The three log ponds were studied in the detail described above in
order to determine if the concentrations of the various
parameters in the effluents were varying with time and also to
determine if the concentrations varied spatially in the pond.
The data reported in Tables 17 through 19 are the 95 percent
confidence range of values for the various parameters for the
influent and effluent by week and also the effluents for all
three weeks of study. These data indicate that the log ponds
studied were at steady state with respect to concentration of
pollutants in the effluent stream. The influent data were not
126
-------
TABLE 26
DATA CORRELATIONS FOR IBG PONDS (01, 02 AND 03)
Independent Dependent Correlation
Variable Variable Coefficient Slope Intercept
01 Pond
COD
COD
COD
COD
COD
COD
BODS
P04t
Turbidity
Color
Nt
BO~D5
P04t
TS~
Nt
Nt
-0.217
-0.055
-0.088
-0.501
0.424
-0.409
-0.304
0.060
-0.0317
-0.070
-0.007
-0.443
0.019
-3.056
-0.019
0.094
5.677
124.358
2.408
45.561
-0.099
293.928
2.407
1.936
56.892
56.892
55.857
54.854
56.892
56.892
19.367
1.049
3,875
120.375
2.035
21.254
0.987
120.042
2.035
2.035
24
24
21
24
24
24
21
21
02 Pond
COD
COD
COD
COD
COD
COD
BODS
P04t
Turbidity
Color
Nt
BO~D5
P04t
TS~~
Nt
Nt
-0.098
-0.521
-0.340
0.455
0.385
-0.305
0.009
-0,037
-0.2i
-2.345
-0.021
0.690
0.023
-1.838
0.001
-0,037
10.970
356.295
4.433
-39.366
-0.977
404.885
2.531
2.541
92.521
92.521
91.733
92.521
92.521
92.104
22.786
1.275
139.375
139.375
2.544
24.474
1.192
235.583
2.544
2.544
24
24
21
24
24
24
21
21
03 Pond
COD
COD
COD
COD
COD
COD
BOD5
P04T
Turbidity
Color
Nt
BO~D5
P04t
TS~~
Nt
Nt
-0.265
-0.070
0.028
-0.074
-0.018
-0.070
-0.038
0.160
-0.019
-0.252
0.003
-0.107
-0.001
-0.168
-0.003
0.427
7.586
377.318
2.907
46.448
1.649
168.172
3.377
2.579
13L.456
13L.456
131.276
13L.450
13L.450
13L.450
33.457
1.653
5.043
344.174
3.285
32.379
1.552
146.083
3.285
3.285
23
23
21
24
24
24
21
21
127
-------
TABLE 27
RELATIONSHIP OF THE VARIOUS PARAMETERS
TO COD FOR LOG PONDS 01, 02, and 03
Ratio
Color/COD
Turbidity/COD
BOD/COD
P04/COD
NT/COD
TS/COD
TSS/COD
01
2.116
0.068
0.338
0.017
0.055
2.110
0.527
02
1.509
0.098
0.275
0,013
0.041
2.558
0.421
03
2.681
0.038
0.243
0.012
0.034
1.089
0.275
Average Ratio
2. 02
0.068
0.285
0.014
0.043
1.919
0.408
128
-------
quite as reliably steady as illustrated by the large range of
values. The areal data on the ponds indicate that not only were
the effluent concentrations steady with time, but also that the
effluent concentrations of a parameters represents the
concentration of that parameters throughout the pond. The
various points in the ponds were chosen for areal sampling
because it was anticipated that these would represent sluggish
areas in the pond and perhaps contain higher concentrations of
pollutants. Because that did not occur, it would appear that the
ponds are well mixed with respect to their detention time.
The results of data correlations for the three ponds are shown in
Table 26. As indicated by the correlation coefficients in Table
26, poor correlation of the data was observed between all
parameters studied, indicating that the data varied in a random
fashion. The randomness of the data in this case does not mean
that the variations of the parameters are not related, but rather
that the parameters are varying insufficiently to cause an
observable trend. The ratios between the various parameters for
the three ponds are shown in Table 27. It can be seen that the
ratios of BOD, PO<*, and Nt to COD seem to be decreasing when
progressing from Log Pond 01 to Log Pond 02 to Log Pond 03. This
seems reasonable when considering that the age of the pollutants
increases in the same order. However, the difference between the
ponds is such that the average ratio will be an approximate
representation of log ponds for all detention times.
It is recognized that a comprehensive description of the effluent
from a log pond must include the following factors:
1. Type of logs in the pond;
2. Number of logs in the pond;
3. Age of the logs;
4, Detention time of the logs;
5. Size of the pond;
6. Hydraulic detention time; and
7. Quality of water entering the pond.
All of the above listed parameters, with the exception of the
type of log and the age of the logs were taken into account in an
attempt to model the effluent from the log pond. The log pond
was considered to be a "continuous feed stirred tank reactor"
(CFSTR) with the logs acting as the feed of pollutants and the
influent water acting as both the feed of pollutants and the
water feed. The use of this model was justified by the
uniformity of the log pond effluent with time and also the
uniformity of the log pond water from point to point within the
pond. The leaching rate of pollutants was assumed to be a first
order reaction up to a maximum level that was dependent on the
volume of the pond and the number of logs in the pond. The
maximum concentration was determined from Log Pond 03 and Log
Pond 09 which are norflow ponds during the summer. The five
first order leaching constants for the various ponds calculated
from the model varied from 0.00121 to 0.00308 with an average
129
-------
value of 0.00205. The equation for predicting the effluent
concentration using t£e model is:
Co.* kKt L
Ceffl. = 1 + k
t
Where:
Ceffl = effluent COD concentration (mg/1)
Co = influent COD concentration (mg/1)
k = first order rate constant (davs-1)
t = hydraulic detention time of the pond (days)
L = quantity of logs on the pond (cu m)
V = pond volume (liters)
K = constant to account for maximum COD concentration =
Cu V/L
Where :
Cu = ultimate COD concentration in the non-
flowing pond (mg/1)
K = 2957.3 X 10« mq
cu m
When this equation was used to predict the concentration of the
five ponds, and then the predicted value compared with the
observed value of the effluent concentrations, the data agreed
well as indicated by a correlation coefficient of 0.953.
Using the data collected in this study and the model used for
relating that data to the various physical parameters, it was
possible to approximate the character of the effluent streams
from log ponds for different physical characteristics. These
data are listed in Table 28. It can be shown that despite the
concentration of the effluent from Pond A being less than that
from Pond Br the total amount of materials removed from Pond A
per day is significantly higher than that removed from Pond B.
In a similar fashion, even though the concentration of pollutants
in the water in Pond E is highest of the five ponds, the total
pounds per day of pollutants from Pond E is zero because the flow
is zero. In addition, the greater depth of Pond D over Pond C,
all else being constant, yields lower effluent concentrations and
total pounds of pollutants. These observations lead to the
conclusion that minimum pollutant release would be obtained by no
flow, or if the flow must be allowed, it should be minimized and
the pond depth made as great as possible.
130
-------
TABLE 28
TYPICAL WAS1E STREAMS FROM LOG PONDS
Parameter
Hydraulic Flow (Cu M/Day)
Log Loading (Thousand Cubic
Meters)
Area (Hectares)
Depth (Meters)
Initial Concentration, C0_
Calculated Parameters
Pond Volume (Million Liters)
Detention Time (Days)
COD (mg/1)
Color (Color Units)
NT (mg/1)
P04T(mg/1)
BOD5, (mg/1)
Turbidity (JTU)
TS (mg/1)
TSS (mg/1)
Log Pond A
38,000
19
20
1.5
0
308.33
8.146
3.0
6.3
0.13
0.04
0.8
0.2
5.8
1.2
Log Pond B
3,800
19
20
1.5
0
308.33
81.46
26.1
54.8
1.-12
0.37
7.4
1.7
50.1
10.6
Log Pond C
3,800
37
20
1.5
0
308.33
81.46
52.3
109.8
2.25
0.73
14.9
3.5
100.4
21.3
Log Pond D
3,800
37
20
3.0
0
6 6.73
162.94
45.7
96.0
1.97
0.64
13.0
3.1
87.7
18.6
Loq Pond E
0
37
20
3.0
0
616.73
00
179.5
377.0
7.72
2.51
51.2
12.2
344.5
73.2
-------
The Model Log Pond
The representative log pond is located in the Northwest. The
pond is constructed from a field about 20 ha (50 ac) in size that
is fairly flat. Retaining walls for the log pond are formed by
dozing the soil from the center of the field to the edge. An
effluent structure, usually of concrete, is installed such that a
water depth of 1.5 to 3.0 m (5 to 10 ft) is maintained throughout
the pond. The pond may receive surface water runoff from an
adjacent area, or it may be completely isolated from all
precipitation except that falling directly on the pond. In some
cases, the pond is fed from springs, irrigation ditches, or
rivers. Most log ponds require the addition of water during the
dry season.
The logs are dumped from a truck or train into the pond and
floated to a temporary storage area. The logs are then sorted
with small boats called mules. The logs may be bundled for
storage, stored loose, or moved directly to the mill feed area of
the pond, if one exists. The logs may be stored in the pond for
a year or more, but generally they are stored only long enough to
insure an adequate supply for the mill during the season when
timber harvesting is difficult.
The model log pond us ed for consideration in the following
sections would have characterises similar to those shown for Log
Pond C in Table 28. The characteristics of the effluent would
also be the same as that for Log Pond C.
STORAGE OF LOGS ON LAND (WET PECKING)
The sprinkling of logs stored on land occurs in all areas of the
U.S. The purpose of sprinkling is to prevent deterioration of
the wood during the storage period between harvesting and further
processing at the facility. Some species of wood are more
susceptible to deterioration during this storage period than
others. Realistically, it is only necessary to keep the logs wet
during dry periods. In general, however, industry practice
appears to be that, if the facility practices sprinkling of logs,
the system continues to operate during periods of precipitation.
The volume of water applied and/or the number of spray nozzles
may or may not be adjusted depending on the volume of the logs in
storage at any given time.
Most decks are sprinkled with the "rainbird" type of sprinkler
which allows about 0.2 Ips (3.2 gpm) of water to flow from the
nozzle. The number of rainbirds used on a particular land deck
does not appear to be related to the size or shape of the deck,
but rather to the opinion of the manager of the operation. Flows
from as low as 5UO 1 per second per million cu m (20 gpm per mm
b.f.) to as high as 6,750 Ips per million cu m (250 gpm per
million b.f.) have been observed.
In some cases, mist type spray nozzles are used for sprinkling
land decks. The flow from these nozzles is considerably less
132
-------
than from rainbird type sprinklers. The water used for
sprinkling the deck is usually relatively clean ground or river
water. In the arid areas of Oregon and Washington, the water is
usually applied in a single use operation, in which the water
passes over the deck and then flows off the property to the
nearest drainage area. The pollutants present in this runoff are
primarily leached materials from the logs.
The recycling of wet deck water is practiced in the South and
Southeast and, to a limited extent, in the West. The water lost
by evaporation in the recycled wet deck is usually replaced by
water from a convenient fresh water source. The runoff from the
wet deck during the rainy season is usually allowed to overflow
the small recycle pond.
The characterization of the runoff from a wet deck has been
attempted and reported in the literature in only one case.
Schaumburg reports the measurement of the BOD of the leachate
from a large wet deck to be 19 mg/1. It can be estimated that
the deck contained about 8.7 x 103 cu m (3.7 million bd ft) of
logs and the flow rate of water over these logs was measured as
1,610 cu m per day (0.426 mgd). In addition to this, a
laboratory setup was constructed in which the wet deck runoff was
recycled. It was found that most of the pollutant parameters
increased in concentration up to about 100 hours of operation and
then assumed a fairly constant value after that time. It was
also found that Douglas fir logs yielded significantly higher
pollutant levels than Ponderosa pine logs. This was the opposite
of that observed for logs submerged in water.
The data in the literature were found to be inadequate to
properly characterize the waste water generated by wet decking.
For this reason, eight wet decking operations in the Washington-
Oregon area and six in the South and Southeast were studied. The
data collected from this sampling program are listed in Table 29.
The first eight samples are from the West coast and the last six
are from the Southeast and South.
Seven of the eight West coast wet decks sampled did not recycle.
Using COD as a measure of the pollution of the water from the wet
deck, it was possible to find satisfactory relationships between
the COD, the volume of logs in the deck, and the flow rate of the
water over the deck. A simple curve fitting technique was used
to obtain a relationship of the form:
COD = 131.3 X 10* (L/Q) + 42.33
Where:
L = volume of logs in the deck (cu m)
Q = flow rate of water over the deck (I/sec)
The relationship between the observed COD in the runoff from the
seven non recycled wet decks and the calculated L/Q was such that
a correlation coefficient between the other parameters measured
133
-------
CO
TABLE 29A —
CHARACTERISTICS OF EFFLUEOT FRCM WET DECKING OPERATIONS
Total Total
Total Total Total Volatile Volatile
Plant
75
75
75
44
44
29
73
72
76
76
77
78
79
80
PH
-
-
-
-
-
-
-
-
6.25
6.02
6.9S
7.84
7.S2
7.2
Reeyclg
No
No
No
No
No
Yes
No
Ho
Yes
Yes
No
Yes
No
Yes
Color
57
29
53
153
104
99
34
127
400
400
100
300
-
-
Turbidity
6
0.7
6
0.9
1.9
53
10
5
10
2.5
17.0
2.5
3.2
-
BjO..^
52.1
11.0
38.4
14.2
17,6
27
-
17.0
21.0*
3,0*
- *
„ *
. *
191
C.O.D.
67.0
56.6
45.5
133.3
107.8
98
54.9
78.4
212
115
16.8
82.8
40.5
358
0.73
1.15
.45
.62
.43
4,10
1.12
2.89
0.63
0.31
.13
0.31
,16
7.0
*t
1.69
0.80
0,59
2.24
.81
1.36
1.50
.76
2.63
1.90
1.23
0.88
.32
1.0
Total
Sol Ids
105
76
91
440
101
347
170
208
310
201
98
292
232
826
Suspended
Solids
18
4
36
a
28
50
85
63
122
46
19
20
27
23
Dissolved
Solids
87
72
55
432
73
297
85
145
188
155
79
272
205
806
Volatile
Solids
77
57
33
99
95
no
67
100
166
102
41
133
98
246
Suspended
Solids
17
7
8
0
1
91
44
30
-
-
-
-
-
12
Dissolved
Solids
60
50
25
99
94
19
23
70
-
-
-
-
-
234
Phenols
fag/ 11
44.4
82,6
52.8
61.1
37.1
26.7
170.8
97.9
27
6
<5
<5
0.15
20 .
Inventory
6.9
1.15
1.725
3.68
2.07
25.3
1.15
46
.46
.69
.23
1.61
.345
1.219
Flow
(I/sec)
32.9
7.7
12.6
3.7
4.3
20.1
7.3
113.6
1.8
3.2
-
11.2
1.2
.6
. Q./L** L/Q**
174
244
267
32
76
29
232
90 -
145 .00700
167 .00600
-
253 .00395
129
18 .05521
COO
-
-
-
-
-
-
-
-
-
212
115
.
82.
358
Apparent toxicity of samples
**Q/L • flow/Inventory
L/Q • Inventory/flow
-------
TABLE 29 B
E&TA CORRELATION FOR WEST COAST WET DECKING
Independent
Variable
COD
COD
COD
COD
COD
P0£
BOD
COD
Dependent
Variable
NT
Color
P04.
TS
Turb.
NT
NT
BOD
r*
0.522
0.878
-0.173
0.74,1
-0.882
-0.239
0.230
-0.5]4
m
0.010
1.317
-0.004
2.974
-0.085
-0.2.15
0.006
-0.402
b
0.414
-22 .707
1 .271
-60.774
11-854
1.41D
1.004
63.855
*r - correlation coefficient
135
-------
and COD could be determined. As can be seen from Table 29A. COD
correlated well with color and total solids, but not turbidity.
However, the correlation of COD with the nutrients and the
nutrients with themselves was very poor. The phosphate
concentrations from the wet deck appears to be about 1.0 mg/1 or
less, whereas the nitrogen concentration appears to be rather
erratic. The BOD/COD ratio for the wet decking varied from a low
of 0.10 to a high of 0.84. The higher value was higher than
observed for any other data in the raw material storage and
handling. The high variation in this ratio accounts for the poor
correlation between BOD and COD.
The above equation was used to calculate the expected
concentration of COD from the log deck reported by Schaumburg and
a value of 87 mg/1 was obtained. If the BOD/COD ratio were 0.25
(an average value for wet decking) , the BOD for this wet deck
would be about 22 mg/1. This compares favorably with the
reported BOD concentration of 19 mg/1.
The southern wet decks with recycle fit the form of the equation,
but the constants are different. The equation for characterizing
southern wet decks with recycle isi
COD = 168.9 X 10* (L/Q)
109.8
The fit between the observed COD and the calculated parameters
L/Q was such that a correlation coefficient of 0.915 was
obtained.
The one observation of southern wet decking without recycle did
not fit either equation. In addition, the western wet deck with
recycle did not fit either equation.
The concentration of pollutants in a wet decking water system is
a function of the number of logs in the deck, the species of
logs, the flow rate of water being sprayed over the deck, and
whether or not the wet deck water is recycled. If the runoff
from the wet deck is recycled, the concentration of pollutants is
generally higher, but these pollutants are not discharged from
the system unless rain water causes overflow from the recycle
pond.
The Model Plant
Using the equation derived in this study and "typical" wet deck
characteristics, it is possible to generate the effluent quality
for a wet deck with recycle and one without recycle. These
"typical" effluents are shown in Table 30 .
The hydraulic flow and the number of logs in the deck are
considered to be typical values based on field operations. The
concentrations of pollutants in Table 30 are not inclusive of all
the concentrations to be expected, but may be considered to be
representative of a typical wet decking operation.
136
-------
TABLE 30
TYPICAL WASTE STREAM FRCM WET DECKING OPERATIONS
Parameter
Hydraulic flow, I/sec.
Logs in deck, cu.m.
Type of Discharge
Area required, hectares
Western
Wet Deck, No Recycle
9.5
3500
Continuous
1.52
Calculated or Estimated Parameters
COD, mg/1 77.7
BOD, mg/1 20
Color (color units) 80
fft, mg/1 - 1.2
PP04., mg/1 0:7
Total Solids, mg/1 Variable
Total Suspended 50
Solids, mg/1
Southern
Wet Deck, With Recycle
9.5
3500
Intermittent* or None
1.52**
155
38
50
1.3
0.5
Buildup
00
Intermittent flow occurs whenever rain is enough to exceed the unused
volume of the sedimentation basin
**Will require additional area for recycle pond
137
-------
STORAGE OF LOGS ON LftND (DRY DECKING)
Since no water is used in the dry storage of logs, no studies in
regard to the generation of pollutants have been conducted.
Realistically, however, it must be considered that a significant
polluted stream might be produced by storm runoff from dry decks.
Some differences between wet decks and dry decks during
precipitation periods can be expected. One primary difference is
that the runoff from an established wet deck tends to be
channelized, i.e., has eroded definite patterns of flow, and to
be essentially free of soil particles. The storm runoff from a
dry deck, on the other hand, tends not to be channelized and
usually contains considerable concentrations of suspended solids
contributed by the soil. In this respect, a new wet deck can be
more comparable to a dry deck. This effect was observed in the
effluent from one wet decking operation which even after 24 hours
from spray initiation still contained significant soil
contamination.
It was felt early in the study that despite the lack of
information concerning dry decking, it might be possible to
establish a definitive relationship between the effluents of wet
decking and dry decking and thereby characterize the dry decking
effluent. In an attempt to accomplish this, a field (experiment
was conducted.
Fifty-three slash pine logs were placed on supports such that the
logs were maintained at a distance of 46 cm (18 in) above the
ground. The 5 meter (16 foot) wide, one and a half meter (five
foot) high deck contained logs with an average length of 12.3 m
(40.4 ft), an average butt diameter of 31.55 cm (12.42 in), and
an average top diameter of 18.44 cm (7.26 in). The butt ends
were all placed at one end of the deck. Three plastic lined
basins were constructed under the log pile in such a manner as to
collect all water percolating through the decks at each end and
in the middle.
The first period of precipitation amounted to a total of 1.47 cm
(0.58 in) of rain fall and samples were collected from the basins
after the first 1.22 cm (0.48 in) and at the termination of
precipitation. The results of analyses showed little difference
in the two samples, and the values shown in Table 31 are averages
for the two samples.
Twenty days later a second rainfall deposited 1.24 cm (0.49 in)
of rain and ten days after that a third storm produced 0.89 cm
(0.35 in). The results of sample analyses are shown in Table 31.
A comparison of the results in Table 31 with those in Table 29
shows that the concentrations of pollutants leaching from the dry
deck are markedly higher than any from the wet deck samples.
For example, the COD concentrations for wet deck runoff ranged
from 15 to 150 mg/1 with one sample concentration 'of 212 mg/1
138
-------
31
FROM DRY DECK EXPERIMENTS
Total Leachate
h-»>
CO
to
Date
10/31/73
11/1/73
11/19/73
11/28/73
Rainfall
(Inches)
0.42
0.16
0.49
0.35
Collected
(liters)
594
155
534
299
_PH
4.9
4.5
6.0
5.7
Color
362
357
455
409
Turb.
24
29
36
-
BOD5
265
299
211
112
COD
1097
1037
773
594
,
TOC
200
214
141
173
EPA
1.67
1.74
1.49
0.59
NT
0.83
1.61
2.05
0.81
TS
868
974
.
509
TSS
162
164
132
IDS
706
810
482
377
TVS
782
875
398
77
Phenols
206
211
223
83
-------
whereas the COD concentrations observed from the dry deck
leachate were generally in the range of 600 to 1200 mg/1. The
COD load contributed by the dry deck for the three rainfalls
amounted to about 1265 grams (2.75 Ib). In this particular case
the load was contributed in about one day of rainfall spread over
about US days. The equivalent load from a wet deck with no
recycle would be contributed in about two days. This tends to
indicate that even though the concentrations of the pollutants in
the leachate coming off the dry deck are high, the total load
contributed by the deck during the actual rain periods is about
the same as a wet deck.
This data is only for one log pile of one particular species of
wood under fairly similar precipitation and climatic conditions.
The difference in concentrations of the pollutants in this
leachate and the wet deck leachate is so great, even though the
total load may be similar, that a correlation between wet decking
and dry decking is not felt to be possible at this time.
STORAGE PILES OF FRACTIONALIZED WOOD
Fractionalized wood and wood products consisting of chips,
sawdust, planer shavings, bark, etc., are commonly stored in
piles in the timber products industry. These piles and the
associated water pollution are similar in some respects and
dissimilar in others. In terms of waste water streams, a prime
consideration must be given to the quantities of materials that
can be expected to be leached from the piles. There are several
factors which affect leaching rates. These include: 1) type or
species of wood in the pile, 2) sizes of particles in the pile,
3) amount of water generated by the pile, and 4) age of particles
in the pile. The effects of species on leaching rates can be
illustrated by Table 32 which presents the results of analyses of
cold water solubles from the bark and wood of several species. A
considerable variation of concentrations can be observed.
Particle size has an effect on leaching rate in that larger
particles generally tend to have slower leaching rates than
smaller particles because of the smaller areas of surface
exposure. The relative size of particles in piles is illustrated
graphically in Figure 35 since they are usually greater than 10
mm in size.
Perhaps the most important parameter in the determinations of the
amount of pollutants generated by a pile of fractionalized wood
is the amount of water that passes from the pile. The water may
originate from one or more of several source s. When the
particles are blown on to the pile, water may be added to control
dust. Water may be generated by ground water seeping into the
pile or it may originate from storm runoff flowing through the
pile. The water may be released from particles because of micro-
bial decomposition. Most of the .water from particle piles,
however, originates from rain falling directly on the pile and
passing through it.
-------
TABLE 32
ANALYSIS OF COLD WATER SOLUBLES IN
BARK, WOOD, AND MOSS PEAT •
Species
Western redcedar;
Untreated
Extracted
Redwood:
Untreated
Extracted
Red alder:
Untreated
Extracted
Western Hemlock:
Untreated
Extracted
Ponderosa pine:
Untreated
Extracted
Sitka spruce:
Untreated
Extracted
Douglas fir:
Untreated
Extracted
Sour sawdust
Moss peat:
Untreated
Extracted
PH
Bark
3.
4.
3.
4.
4.
5.
4.
4.
3.
3.
4.
6.
3.
3.
"
2
5
2
8
6
0
1
4
8
9
9
4
6
8
3.8
4.4
Water
soluble
Wood Bark Wood
3.
4.
4.
5.
5.
6.
6.
4.
4.
4.
4.
6.
3.
3.
2.
5 2.95 6.99
6 -
4 2.35 1.67
6 -
8 11.64 1.43
0 -
0 3.95 3.47
4 -
4 4.35 2.68
2 -
1 10.89 1.27
4
4 5.49 4.65
3 — —
0 - 12.81
1.04
—
Kjeldahl
nitrogen
Bark
%
0.14
.13
.11
.11
.72
.81
.27
.24
.12
.13
.41
.40
.12
.11
~
.83
—
Wood
0.06
.06
.07
.06
.13
.15
.04
.03
.04
.06
.04
.04
.04
.04
.06
C/N
ratio
Bark
378:
392:
473:
457:
71:
62:
212:
223:
422:
429:
130:
127:
471:
513:
~
1
1
1
1
1
1
1
1
1
1
1
1
1
1
58
—
Wood
810
835
753
876
377
320
1,234
1,618
1,297
895
1,214
1,194
1,268
1,242
893
Total solids in 12 successive 1:10 water extractions, 24 hours each
-------
100,
ro
8Q__J
60_j
2
40
20.
SIEVE OPENING (mm)
SIEVE NUMBER
FIGURE 35 PARTICLE SIZE ANALYSIS FOR DOUGLAS FIR BARK AND SAWDUST
-------
The age of a fractionalized wood pile is an important criterion
in determining the quantity and quality of leachates from the
pile in that older piles may be saturated and yield their water
more readily. The older pile may also be undergoing microbial
decomposition which can increase the concentration of leachates
or, conversely,the microbial decay may have progressed to the
point that further leaching produces relatively low
concentrations.
The factors discussed above and others affect the character of
the waste stream from a fractionalized wood pile to varying
degrees. In many cases, the problem is compounded by the pile
being located on bare earth which may allow the waste stream to
percolate into the ground. Partly for these reasons few studies
have been conducted on leachates from fractionalized wood piles
and, in fact, few cases of visible leachates have been observed.
Virtually no characterization of the waste waters originating
from piles of fractionalized wood had been established prior to
the current study.
while there are no data in the literature concerning the
character of leachate from fractionalized wood piles in the
field, there have been three laboratory studies performed on
leachates from piles, and numerous works on the alteration of
chip quality in chip piles experiencing biological decomposition.
An annotated bibliography prepared by Hajny covers
comprehensively the effects of chip quality in outside storage.
The laboratory study by Asano and Towlerton illustrates the
pollutant levels that may be expected in leachates from chip
piles. The study reported COD concentrations of greater than 500
mg/1 and color values of about 3,000 units. About 10 hours of
agitation were required to produce these concentrations. Using
submerged agitated bark, Benedict observed COD concentrations of
about 4,000 mg/1, BOD concentrations of greater than 2,000 mg/1,
and color values of about 7,000 units for a mixture of fresh
softwood and hardwood bark. The Benedict study is probably more
representative of the leachates to be expected from a bark pile
than the laboratory study by Asano and Towlerton is of the
leachate to be expected from a chip pile. The ratio of bark to
water in the Benedict study is closer to that expected in a bark
pile than the ratio of chips to water in the Asano and Towlerton
study. .Another bark study by Sproul and Sharpe shows COD
concentrations of about 500 mg/1 and color units of about 2,000.
These concentrations remained relatively constant over the
duration of the 90 day test.
During the course of the current study, leachates from several
bark, chip, and sawdust piles were collected and analyzed. As
indicated in Table 33 the data seem to be highly variable. In
addition, it can be observed from Table 33 that bark piles, chip
piles, and sawdust piles all produce leachates that can be high
in concentration. It was possible to investigate the effect of
rainfall intensity on the quantity and quality of leachate from
chip and sawdust piles by critically examining the data shown in
-------
TABLE 33
CHIP PILE RUNOFF RESULTS
Date Flow Phenols
Source 1973 (I/sec) Color pH NT COD* PO^ BOD* TS* TVS* TSS* TVSS* TDS* mg/l
Chip Pile+ 8/2 — 1560 5.1 — 489 — 117 3927 2544 164 126 3763
Runoff
Plant 80
Chip Pile+ 8/3 — 2250 5.6 — 4368 — 630 4119 2652 854 560 3265
Runoff
Plant 80
Chip Pile+ 10/16 0.1 -- 6.2 9.18 1190 2.00 222** 1050 731 67 — — 239
Runoff
Plant 80
Bark Pile 1/3 0.6 1600 — — 8700 -- — 4800
Runoff
Plant 82
Sawdust Piletf 1/3 0.9 250 — — 1530 — — 1850 —
Runoff
Plant 82
Sawdust Pile 1/3 0.1 " — — — 4358 '1.8 — 5404 2964
Runoff
Plant 81
Chip Pile
Runoff
Plant 81 10/17 0.2 550 6.95 — 237 0.30 3.8 543 309 91 — — 19
*Expressed as mg/l
**Possible toxlcity
+Collected and analyzed by Temple Industries, Dlbold, Texas
^/Collected and analyzed by CH2M-Hill, Corvallis, Oregon
-------
34
CHIP PILE RUNOFF SUMMARY
Date
1/8/73
9:00 a.m.
J/9/73
9:00 a.m.
V12/73
1:00 p.m.
l/tS/73
1/3)8/73
9:00 a.m.
3/19/73
4:00 p.m.
Point of Runoff
Sample
Redwood
Whitewood
Sawdust
Total
Redwood
Whitewood
Sawdust
Total
Redwood
Whitewood
Sawdust
Total
Redwood
Whitewood
Sawdust
Total
Redwood
Whitewood
Sawdust
Total
Redwood
Whitewood
Sawdust
Total
Flow
I/Sec.
2
10
16
6
32
6
10
6
22
4
6
0.5
10.5
3
4
4
1
BOD
(mg/n
840
iao
210
294
2JO
320
CO)
(mc^l)
460
478
2270
750
553
2500
913
1220
2460
278
238
1820
797
672
1186
71]-
948
Rainfall
cm/day
2.44
444
3.35
010
3.07
1.42
*Data from industrial contact 623
IkS
-------
Table 34. A plot of the flow from the various piles and the
total flow versus the rainfall intensity (Figure 36) shows that
the flow from each of the piles does not begin until the rainfall
intensity exceeds a certain value. The data for the month of
March has been omitted from the plot in Figure 36. The rationale
for this omission was that during the month of January the chip
and sawdust piles were saturated to a certain low level.
Therefore, when it rained with an intensity greater than a
certain level (in this case 2.21 cm (0.87 in) per day), the chip
or sawdust piles could not absorb the rainfall at that rate, and
a portion of the rainfall came off the pile as though the pile
was acting as a roof. In March, after two additional months of
rainfall, the piles were saturated to a greater degree and,
therefore, the intensity of rainfall required to produce runoff
from the piles was significantly less. This is evidenced by the
fact that a rainfall intensity of 1.42 cm (0.56 in) per day in
March produced a runoff rate that would have required a rainfall
intensity of about 2.92 cm (1.15 in) per day in January. Looking
at the total yield that could be expected from the two chip piles
with areas of 2.35 and 3.12 ha (5.83 and 7.70 ac) and the sawdust
piles with an area of 0.39 ha (0.97 ac), the average flow if the
rain fell at a uniform rate for 24 hours would be about 10 Ips
(153 gpm). These figures, 10 Ips (153 gpm) versus 11 Ips (173
gpm), agree quite well considering the inexact nature of most of
the measurements involved in the data. The agreement of the two
figures signifies that the chip and sawdust piles were absorbing
relatively little precipitation.
The COD data in Table 34 shows that the COD is relatively
constant for each of the effluents no matter what the flow. This
indicates that the quantity of pollutants leached from the pile
is directly proportional to the flow from the piles. A washout
phenomenon is expected, but it may occur at greater flow-offs
from the piles. No explanation can be given for the much higher
concentration of COD in the leachate from the redwood chip pile
than from the whitewood chip pile. No information about the
species of chips contained in each pile was supplied with the
data. Typically chip piles for the particleboard or insulation
board processes experience rapid turnover and saturation of the
piles may never be obtained.
The data represented by entry number 4 in Table 33 were not the
only data received on that bark pile. BOD and COD concentrations
for three flows were received and BOD and COD loads coming off
the pile were calculated therefrom. This data appears in Table
35. It can be seen that the amount of COD and BOD leached from
the pile increases about 60 percent when the flow increases from
0.8 to 3.4 Ips (12 to 54 gal per minute). The flow increase from
3.4 to 4.7 Ips (54 to 75 gpm) did not increase the COD and BOD
load. Apparently the bark pile reached the washout point at
about 3.4 Ips (54 gpm) whereas the chip and sawdust piles had not
reached the washout point at 32 Ips (500 gpm).
The seepage of the absorbed water from the particle pile is an
expected phenomenon, but was observed only for sample locations
-------
•p.
-J
O
z
O
O
UJ
37,0 1
31.0
25.0 -
18.0 -
£ 12.0
D.
a:
LJ
6.0 -I
I I.S 2 2.5 3
RAINFALL INTENSITY (CM/DAY)
TOTAL
WHITE WOOD
REDWOOD
SAWDUST
3.6 4.1 4.6 5.1
FIGURE 36 RUNOFF FLOW RATE VS RAINFALL INTENSITY FOR WHITEWOOD AND
REDWOOD CHIP PILES AND A SAWDUST PILE
-------
TABLE 35
BARK PILE EFFLUENT CHARACTER
Discharge
(I/Sec.)
1
3
5
COD
(mg/1 )
6,930
2,530
4,850
COD
(Kg/Day)
453
745
755
BOD5
(mg/T)
3,800
1 ,300
870
BOD5
(Kg/ Day)
\
-------
numbers 6 and 7 in Table 33. For both of these two samples, rain
had occurred for one or two days previous to sample collection
and the rate of leachate production on the sample day was low.
However, the strength of the effluent was relatively high.
Typical Effluent from Fractionalized Wood Piles
Fractionalized wood piles, like most other aspects of timber
products raw material storage, emit highly variable effluent
waste streams both with respect to flow and concentrations. The
leachate stream can emanate from the pile because of the water
held within the pile, because of water flowing on the ground
through the pile, or because of water running off the pile during
rainfall periods. Regardless of the origin, the concentrations
of pollutants in the effluent stream are high. No modeling of
the piles was attempted, but the typical effluent stream is
considered to have the characterization listed in Table 36.
LOG WASHING
As previously mentioned, the practice of log washing is not
common in the industry. Furthermore, the method of washing, the
amount of water used, and the resulting waste water
characteristics will vary from mill to mill. The waste water
characteristics can be expected to vary somewhat depending on the
season of the year and the conditions under which the log was
harvested. Thus, during rainy, seasons of the year, the charac-
teristics of the solids removed from the logs will differ from
those removed under dry conditions. However, these solids are
generally settleable and because the log wash water can be
recycled, these variations are not of significance.
Typically, log wash water will be low in COD and solids as
illustrated in Table 37 (from information collected during this
study). The data shown illustrate waste water characteristics
for recycled wash water as well as non-recycled wash water. It
should be noted that the COD values for the recycle systems are
approximately twice the concentration found in the non-recycled
system. This indicates the possibility of a concentration
gradient which inhibits to a great extent further leaching from
the logs. It should also be noted that the reported values for
solids do not include settleable solids since settleable solids
concentrations vary considerably with log harvesting conditions.
Their removal is the primary reason for log washing.
The representative log washing operation is located at a sawmill
producing 59,000 cu m (25 million bd ft) of lumber per year. The
log wash operates for 16 hours per day, five days per week, and
requires 25 I/sec (UOO gpm) of water at a pressure of 8
atmospheres (117 psi). This is a non-recycle system and,
therefore, the waste water characteristics are similar to those
of Mill A, Table 37.
1«*9
-------
TABLE 37
RAW WASTEWATER CHARACTERIZATION LOG WASH WATER
cn
O
COD
Total
Total Suspended Dissolved Volatile Volatile
Sol ids Sol ids Sol ids Suspended Suspended
Mill
A
B*
C*
mg/1
97
240
258
mg/1
334
442
354
mg/1
73
218
204
mg/1
61
214
150
mg/1
62
214
170
mg/1
-
98
_
m9
5.
3.
1.
T\
6
68
04
mg/T
.10
3.0
.58
JTU
-
530
13.0
Units
70
274
_
NT P04T Turb, Color Phenol
mg/1
79
*Recycle systems
-------
SAWMILLS
Water usage at sawmill operations varies significantly. A
majority of small sawmills do not produce their own power and use
no water at all except for sanitary purposes. On the other hand,
a sawmill producing power, washing logs, and wet decking logs may
use over 38,000,000 1 of water per day (10 mgd).
This disparity in volume illustrates the difficulty in attempting
to discuss a typical sawmill. However, a discussion of various
possible sources and volumes of water use follows.
Table 38 provides a list of sources of water usages in an actual
sawmill and approximate maximum water requirements. The volume
of water used is 737 I/sec (11,682 gpm) or 63,600 cu in/day (16.8
mgd), Of this volume, approximately 93 percent is related to the
production of power rather than to the operation of the sawmill
itself. Actually, only 0.4 I/sec (six gpm) of the total is
directly related to the mill operation and this is absorbed by
the sawdust. However, the fact that a large volume of water is
used in the vicinity of the sawmill is important in that in many
cases this water becomes contaminated prior to leaving the mill
yard. This is the case, for instance, when the point of dis-
charge of uncontaminated cooling water is a log pond.
In many cases the range of water use prohibits the development of
waste water characteristics; however, such information as
available is presented. It should be noted that the information
presented represents the best available information on present
status of water use in the industry. Future technological and
economic developments may result in increased or decreased water
usage. It should also be noted that the following discussion is
directed toward the sawmill processes and does not include a
discussion of log storage waste waters or those resulting from
the presence of glue using operations such as end-jointing which
might be present at a sawmill. These are discussed elsewhere in
this report.
One possible water usage in a sawmill is saw cooling water. The
practice of spraying a fine mist on saws, especially band saws,
is common. Where water is employed for cooling the volume is
small, generally less than 0.06 to 0.12 I/sec (1 to 2 gpm) and no
waste stream is created as all moisture is absorbed in the
sawdust. This practice is sometimes employed in cooling other
types of saws, especially gang saws where the volume of water
used may be on the order of 0.18 to 0.25 I/sec (3 to 5 gpm). As
the volume of water used increases, so does the probability of
creating a discharge. For most saws, however, the volume of
water used can be restricted such that no discharge is necessary.
In fact, only one saw cooling system was observed to produce a
waste water stream.
A notable trend in the industry, is toward the use of thin or
narrow-kerf saws. The narrow-kerf saws are somewhat more
susceptible to dynamic instability than most present day saws.
151
-------
TABLE 38
WATER USAGE FOR AN ACTUAL SAWMILL WITH
POWER PLANT AND LOG STORAGE
Water Pumped
I/Sec
316
316
3
3
0.4
8
28
19
6
2
38
739.4
Volume Lost
I/Sec
—
—
—
—
0.4
—
28
__
6
2
2
38
74.4
Volume Discharge
I/Sec
316
316
3
3
—
8
—
19
—
—
—
665
Source of Use
Condenser No. I
Condenser No. 2
Grate Cooling
Boiler Scaling
Saw Cooling
Compressor Cooling
Boiler Makeup
Bark Wash
Miscellaneous
Fire Protection
(normal)
Log Deck (summer)
Totals
*Sanitary use not included. Also, maximum fire protection use is 388
liters per second.
152
-------
Saw guides, employed to compensate for this instability, use
water, oil and sometimes air mixtures to reduce friction and
pitch buildup on the saws. Such a system designed for an edger,
for instance, would utilize 0.06 to 0.6 Ips (1 to 10 gpm) of
water and up to 2.6 1/hr (0.7 gal/hr.) of water soluble oil.
Thus, oil content of the cooling water may be on the order of
1000 mg/1. As saws become thinner, larger volumes of water may
be required; however, at this time characterization of any waste
water that might result is not possible. Also, the current state
of development of thin-blade saws is such that the sawguide water
required is of a volume that all water is absorbed by the
sawdust.
Many sawmills, especially older ones, utilize steam for various
purposes. In general, where steam is utilized for power such as
in steam driven log carriages, a condensate can be expected to
occur. Generally, the steam powers the carriage and then the
steam is blown-off or wasted to the atmosphere. It is also
common practice to inject an oil mist into the steam to insure
proper lubrication of the equipment. In some cases, the oil
contaminated condensate may be of sufficient volume to form a
waste water stream; however, the volume and oil content of such
streams is highly variable and is usually intermittent.
Cooling water is generally non-contact water such as that used
for cooling compressors and condensers. Turbine pumps and
various other types of hydraulic equipment may require bearing
cooling water. The volume of such cooling water varies
considerably but is generally contaminated by only a slight
amount of oil, if any.
A common practice at sawmills is the dipping of lumber, both
green and dressed, in a preservative solution of, most commonly,
pentachlorophenol. There should be no discharge of this
material. However, often times the dip vats are not covered and,
therefore, receive precipitation and may overflow. Also, as the
lumber is removed from the dip tank, drippage on the ground may
occur. It is also probable that the dip tank eventually becomes
heavily silted with debris and may require blowdown.
Another source of water usage is in lubrication of chain belts
and other conveyor systems. The water is sprayed on the chains
in small volumes. No waste water should result, however, as the
water is absorbed by bark or sawdust.
There is no necessity for waste water generation from most
cleanup operations in sawmills or planing mills. A small volume
of water, generally less than 35-75 I/day (10-20 gpd) will be
required for cleaning various types of applicators which may be
employed. Small spray compartments are utilized to apply stains
and moisture resisting compounds to lumber. The waste water
generated in cleaning the compartments and nozzles should be
recycled and used in makeup for the next batch of material.
153
-------
While no necessity exists for waste water generation from cleanup
operations, it is commonly occurs, especially in cleanup of areas
underneath the mill. The volume used for this purpose has been
reported by industry to be as high as 23,000 Ipd (6,000 gpd).
This stream contains a considerable amount of floating wood
particles and also contains soluble wood and bark constituents,
dust, oils, and greases. COD and total solids concentrations of
100 and UOO mg/1, respectively, have been observed.
Consultation with industry representatives as to the necessity
for this practice resulted in the conclusion that the cleanup of
mill floors can be accomplished by dry cleaning (sweeping) rather
than by the use of water.
The utilization of bark and other wood residues for fuel may
result in a number of waste water sources including leachates
from hogged fuel piles and the presence of bark washing or bark
pressing operations. Possible leachates from bark piles were
discussed previously in this section and that information can be
consulted to obtain an indication of their characteristics. Bark
washing or pressing operations have not been observed in sawmills
and no further information is presently available.
The presence of boilers may result in boiler blowdown and
demineralized backwash. Similarly, furnace grates may require
some water for cleanup. Non-contact grate cooling water may also
be required. Air pollution devices required to reduce emissions
may be wet-scrubbers which require bleed-off of a small
percentage of the recycled flow. Typically, the volume of such
bleed-off is about 0.6 I/sec (10 gpm) with a solids content of
0.5 to 1.0 percent.
Figure 37 is a water balance for a sawmill producing 230 cu m
(100,000 bd ft) per day of dried lumber. It is assumed for this
model mill that the moisture content of the incoming logs is 50
percent and that the dried lumber moisture content is 12 percent
by weight. It is further assumed that the lumber overrun equals
the kerf loss, where overrun is defined as the difference between
the measured volume of a log and the actual volume of lumber
produced, and kerf loss is the volume of wood lost to sawdust in
sawing.
The volume of water used for log washing is equivalent to 25
I/sec (400 gpm), 2U hours per day, and is considered to be
discharged without recycle. The headrig water usage is typical
of a steam driven log carriage. The effluent is considered to be
lost to the atmosphere, the ground or absorbed in the sawdust.
The saw cooling water shown is equivalent to 0.6 I/sec (10 gpm),
21 hours per day, and represents the total saw cooling water
usage for the mill. No discharge results from this usage because
of adsorption in the sawdust. The volume of boiler makeup and
blowdown and compressor cooling water is based on actual mill
usage and it is assumed that these discharges are not further
contaminated by contact with wood or wood residues. The water
used in the dip vat is for dilution of concentrated preservative
-------
83^70-
654.048
,048—tJ
56,775 —»4
1,703—+\
WATER IN LOGS
2,180,160—**] LOG WASH
54,504—*4 SAWING
I
COMPRESSOR
DRY KILN
DIP VAT
DRIED LUMBER
2,180,160
54,504
1
'
1 BOILER
I—*- 654,048
- 56,775
]—*- 71,536
13,437
LITERS PER DAY
WATER IN * 3,030,460
WATER OUT= 3,030,460
FIGURE 37 WATER BALANCE FOR A SAWMILL PRODUCING
60,000 CUBIC METERS PER YEAR
15S
-------
compounds. The model system assumes a covered dip vat which does
not receive rainwater. The dry kiln is assumed to result in no
discharge as 100 percent of the steam condensate is returned to
the boiler. The discharge of 71,500 Ipd (18,900 gal/day) shown
from the kiln consists of water vapor driven from the green
lumber.
Thus, the model sawmill is managed in such a manner as to produce
discharges only from log washing, compressor cooling, and boiler
blowdown, and the various potential discharge points such as mill
cleanup and other sources previously discussed are not present
because of proper water management.
FABRICATION
The discussion of water use and waste water characteristics for
the unit process of fabrication contained herein does not include
the subcategory of fabrication which employs mechanical fasteners
and non-water soluble adhesives since it requires no water and
generates no waste water. Therefore, this discussion is
concerned only with the use of water soluble adhesives in
fabricating operations and the resulting waste water.
Water usage involved with the use of adhesives varies
considerably depending mainly on the form in which the resin is
delivered, i.e., whether the resin is in a dry, powdered form or
a liquid or emulsified form. Table 39 is a list of the most
commonly used resins with the percentage by weight of resin,
catalysts, and additives, and potential makeup water.
Melamine, urea, and urea formaldehyde may be purchased in either
dry or liquid forms. Those resins delivered in liquid form
require no water for makeup but may require dilution to the
proper concentration (Table 39) to obtain a desired viscosity.
Dry resin forms require a substantial percentage of makeup water
as shown. Phenolic, urea formaldehyde, and protein are used much
more extensively in the manufacture of plywood than elsewhere.
Table UO illustrates the amount of glue used at several mills for
specified products and the potential makeup water requirements.
It should be noted that makeup water is actually required only
for the melamine urea mix while the other resins may require some
water for viscosity control.
Other than the small volume of water used for mixing certain
resins, the only water use in fabricating operations is in
cleanup of glue spreaders and mixing tanks. In a typical
operation, the equipment requiring cleanup may consist of some or
all of the following:
Glue Applicator (double roller, extruder, end
or edge jointer)
Resin Mixing Tank
Resin Storage Tank
Catalyst Mixing Tank
catalyst Storage Tank
156
-------
TABLE 39
MAKEUP REQUIREMENTS FOR VARIOUS MIXES
Resin Type
*Melamine Urea
(Borden MU-607-F)
Melamine Urea
(Melural)
*Urea Formaldehyde
(Borden 5H-FM-GA)
Urea Formaldehyde
(Borden 5H)
Casein Blend
(Borden S-97)
*Viny1 Acetate
(Borden WB-905)
Phenolic
(Borden Cascophen 31)
*Phenol Resorcinol
(Cascophen LT-75-FM-282)
Protein
(Borden Casco S-230)
*Liquid Resins
Resin, Percent
by Weight of
Glue Mix
80
65
80
75
28
90
75
83
75
Catalyst, Additives
Percent by Weight
of Glue Mix
16
15
13
Makeup, Water
Percent
by Weight
35
25
72
25
25
157
-------
Figure 38 illustrates a typical liquid resin glue line, including
catalyst mixture, and a typical dry resin glue line requiring
only water for mixing. The volume of water used in cleanup
varies from operation to operation depending on the number of
applicators and mixing tanks, the frequency of cleanup, and
cleanup techniques. The number of applicators is related to the
production capacity of the operation and is also a function of
the efficiency of the whole operation. Thus, efficient lay up
operations in a laminating plant can increase production without
increasing the number of applicators required.
The number of storage and mixing tanks present is determined by
the production of the plant, the amount of glue required per day,
the type of glue used, and the type of applicator used.
Generally, liquid resins such as phenol resorcinol require
controlled temperature storage in tanks. This type of glue also
requires the addition of a catalyst which is generally a powdered
substance requiring makeup water and mixing prior to its being
added to the resin. Mixing of the resin and catalysts,
generally, occurs in a separate mixing vessel. The exception to
this is observed where extruder applicators are used. In this
case, mixing may occur during transfer of the resin and catalyst
from their respective storage tanks by passing them through a
helical mixing chamber. Powdered resins usually require only dry
storage and one mixing tank.
The frequency of cleanup of mixing vessels is usually daily.
According to industry representatives, resin storage tanks do not
require cleaning. Glue applicators have been observed to be
cleaned daily, once per shift, and even twice per shift. Cleanup
is required whenever use is suspended on any applicator. Various
cleanup techniques which can be utilized to reduce the volume of
water required will be discussed in detail in Section VII,
Control and Treatment Technology. These techniques include the
use of steam, high pressure nozzles, dry scraping, and the
application of grease where possible to applicator surfaces.
Table U1 indicates waste water volumes observed at various mills
and operations during these studies.
Waste Water Characteristics
Characteristics will vary considerably from mill to mill
depending on the type of resin used and the volume of water used
during cleanup. This degree of variability complicates any
attempt to develop waste water characteristics. However, such
data as are available on characteristics of various glue wastes
are presented in Table 42. These data are the product of
analyses of actual waste water streams during this study.
In order to more thoroughly characterize the various glue wastes
found in fabrication, samples of undiluted resins were analyzed.
This is considered adequate characterization in that, as
demonstrated in Section VII, no discharge of the wastes should
occur and adequate control is obtainable without further
characterization of the wastes. In order to relate these
160
-------
TABLE 41
VOLUME OF WASTE WATER REPORTED BY VARIOUS MILLS
Number of Frequency
Volume Applica- of clean- Volume of
Mill
A
B
C
D
Type of
Product
Garage Door
Beams
Finger
Jointed
Lumber
Beams
Beams ,
Decking
Finger
Jointer
Decking
Beams
Type of
Glue
Poly vinyl
Phenol
Resorcinol
Poly vinyl
Phenol
Resorcinol
Phenol
Resorcinol
Resorcinol
Mel ami ne
Urea
Phenol
Resorcinol
of Lumber
(cu; m/day)
2
30
.
190
470
-
20
10
tors/Mixing
Tanks
1/0
1A
I/O
2A
5/2
2/0
1/1
1/1
up (times
per day
1
1
1
1
1
6
1 i
)
Wastewater
(liters/day)
380
190
190
380
4,500
2,300
3,800
161
-------
TABLE 42
CHARACTERISTICS OP GLUE WASWATER (ng/1)
CO
BOD
COD
X
2
3
4 a
4 b
15,900
-
710
4,880
_
OJ5.70I
-
5,671
3,84:
_
TS
DS
5,917
SS
OJ5.700 7,910 6,850
8,880 6,310
5,670 5,890 3,360 2,530
1,284 545 739
TVS VDS
886 235
687 5,233i 5,146 403 4,713
vss
-
-
-
65i
713
Phenols
4.16
0.14
-
127
327
Nt
21.8
U640
-
3.28
952
P04
2.46
20.2
-
1.19
4.95
PH
9.77
5.25
10.8
-
_
NOTE: Mills l and 2 use phenolic glue
Mill 3 uses urea glue
Mill 4a uses phenol resorcinol
Mill 4b uses resorcinol
-------
analyses to expected waste water characteristics, a dilution of
40 to 1 of water to glue is assumed to occur. The results of
these analyses are presented in Table 43. The data demonstrate
the variability in concentrations one would anticipate because of
the different glues. The analyses presented for the phenolic,
protein, and urea glues were taken from a publication by Bodien.
The remaining analyses were performed during this study.
Model Operation
For the purpose of developing control technology and associated
costs for fabrication operations, a model fabrication operation
has been developed. The model fabrication operation may be
producing any of a variety of products such as doors, decking,
end-jointed lumber, or laminated beams. Thus, production rates
are not as meaningful as an indicator of expected volume of waste
water as is the number of pieces of equipment requiring cleanup.
On this basis, two model fabricating operations are assumed:
Model I consists of one double roller spreader, a finger jointer,
and a small mixing tank. The type of glue used may be any of
those previously discussed. Observation of various cleanup
operations indicate that approximately 750 Ipd (200 gpd) of waste
water results from cleaning the above equipment as follows:
Double roller spreader - 370 Ipd
Finger jointer - 190 Ipd
Mixing tank - 190 Ipd
Total 750 Ipd
Model II is applicable to large industrial glue users other than
plywood and is most applicable to the laminated structural
products industry. A large laminated beam plant, for instance,
may use five face glue spreaders, extruder or roller type; three
finger jointers; a catalyst mixing tank; and either a catalyst
storage vessel or a resin-catalyst mixing tank. The spreaders
will require cleanup on a daily basis while the finger jointers
are cleaned once per shift, i.e., three times per day. Other
possible water usages that can be expected are glue mixing room
floor cleanup and delivery truck washdown. Occasionally
imperfect batches of glue may require dumping and subsequent
equipment cleanup. The expected volumes of waste water for such
an operation are as follows:
Spreaders (5) - 1890 Ipd
Finger jointers (3) - 1700 Ipd
Catalyst Mixer - 380 Ipd
Glue mixing tank (2) - 760 Ipd
Miscellaneous cleanup - 950 Ipd
Total 5680 Ipd
163
-------
TABLE 43
AVERAGE CHEMICAL ANALYSIS OF GLUE
VRSTE VCVTER (ASSUMING A 40; 1 DILUTION WITH' V&TER)
Analysis
(mg/kg)
COD
BOD
TOC
P04J
TKN
Phenols*
S.S.
D.S.
T.S.
TVSS
TVS
Phenolic
Glue
16,325
12,500
4,400
3
30
12,850
2,300
7,625
9,925
42,000
86,000
Protein
Glue
4,425
220
1,300
7
300
45.3
1,475
2,950
4,425
850
3,425
Urea
Glue
10,525
4,875
2,250
18.9
533
-
86,500
5,150
13,750
8,650
13,750
Casein Mel ami ne Phenol
Glue Urea Resorcinol
5,500 11,600 26,000
_
-
- -
- -
3,600 1,200 102,500
-
- -
23,000 6,000 1,400
_
6,600
Polyvinyl
Acetate
15,000
-
5,000
-
-
-
1,000
1,000
12,000
5,600
12,000
*Phenols = Kg/Kg
-------
INSULATION BOARD
Specific Water Uses
An insulation board plant producing 270 metric tons/day
discharges 3,400 cu m per day (0.9 mgd) of waste water and
evaporates an additional 380 cu m per day (0.1 mgd) of water.
While the major waste water stream results from excess process
white water, quantities may also be discharged from such
operations as chip washing, dryer washing, and finishing, and
from air pollution contol devices. The waste waters resulting
from the handling and storage of raw materials have been
previously discussed.
Chip Washing - After the appropriate raw material handling
operations previously discussed, the first step considered to be
part of the subcategory of insulation board production is chip
washing. Chips may be washed in order to remove grit, dirt,
sand, metal, and other trash which may cause excessive wear and
possible destruction of the refining equipment. In additori to
removing undesirable matter, chip washing may result in chips
with a more uniform moisture content and, in northern climates,
assists the thawing of frozen chips. Chip washing is practiced
by virtually all plants utilizing chips as a raw material and
plants utilizing chips as a major portion of their furnish
comprise approximately 70 percent of the insulation board
industry. In the future, with the projected increase in the use
of forest residues and whole tree utilization, essentially all
mills are expected to be using chip washers.
Water used for chip washing is usually recycled to a large
extent. A minimum makeup of approximately 400 1 per metric ton
(95 gal per ton) is required in a closed system because of water
leaving with the chips and with sludge removed from settling
tanks. However, up to 4,200 1 per metric ton (1,000 gal per ton)
water usage has been reported from mills that discharge
quantities of chip wash water to waste. Water used for makeup in
the chip washer may be fresh water, cooling water, vacuum seal
water, or recycled process water.
Process White Water - Water used to process and transport the
wood from the fiber preparation stage through mat formation is
referred to as process white water. The water use in this area
is represented in Figure 39. The process white water, accounting
for over 95 percent of a plant1s total waste water discharge
(excluding cooling water), will be discussed in terms of two
streams: 1) fiber preparation white water system and 2) the
machine white water system.
The fiber preparation white water system is considered to be the
water used in the refining of stock up to and including the
dewatering of stock by a decker or washer. As previously
discussed, there are three major types of fiber preparation
utilized in the insulation board industry: 1) stone groundwood,
2) mechanical disc refining (refiner groundwood), and 3) thermo-
165
-------
cn
CD
r«>8i
WOOD "™^^| "EFININO "^STOCKCHEST ^"4 DECKER ^4 STOCK CHE
(50)
*• WAT
+- WAT
(X) APPR
IN PR
(25)
0,615]
;R IN
ER OUT
II) 1 (IS)
[87,137] |[-84,7I6] &-
1
1
DXIMATE FIBER CONSISTENCY — rii""^
OCESS 1^Lllt385J
••J FORMING H
31 ^l MACHINE
TO ATMOSPHERE
|[-WO]
•• DRIER
(t.5) t (SO)
1
>,460] [-56,697]
1
^ TO TREATMENT
*[-ll,55S]
[LITERS WATER]
* INCLUDES HOUSEKEEPING WATER
OB)
FINISHIN8
FIGURE 39 WATER BALANCE FOR A TYPICAL INSULATION BOARD PROCESS
-------
mechanical disc refining. The water volume utilized by each of
the three methods is essentially the same. In the general case,
as shown in Figure 39r the wood enters the refining machine at
approximately 50 percent consistency (50 percent solids by
weight), and is fiberized and diluted to a consistency suitable
for screening (approximately one percent). The stock is then
dewatered at the decker to a consistency of approximately 15
percent before being repulped. This is a water deficient section
of the process in that more makeup water is necessary than water
is discharged because of the quantity of water leaving with the
stock. The variations of water use by the refining process are
determined by the point where the water is added. In all cases
water is added to dilute the stock as it leaves the fiber
preparation section. However, in the case of stone groundwood,
the stock is flushed from the refining machine by a shower of
water that is sprayed onto the revolving stone. There is some
water used for consistency control in the mechanical and thermo-
mechanical disc refiners. Also, water is added in the thermo-
mechanical pulping in the form of steam prior to the chips
entering the refiner.
In the machine white water system, after the dewatered stock
leaves the decker at approximately 15 percent consistency, it
must again be diluted to a consistency of approximately 1.5
percent to be suitable for mat formation. This requires a
relatively large quantity of water of approximately 60,000 1 per
metric ton (14,400 gal per ton). The amount of dilution required
can be calculated from the relationship:
M(y) = M(x)/C-M(x)
where:
M(y) = mass of dilution water required M(x) = mass of wood being
diluted, and C = consistency.
The redilution of the stock is usually accomplished in a series
of steps. The stock usually receives an initial dilution down to
approximately 5 percent consistency, then to 3 percent, and
finally, just prior to mat formation, to approximately 1.5
percent. This sequence is done primarily for two reasons: 1) to
allow accurate consistency controls and more efficient dispersion
of additives, and 2) to reduce the required stock pump and
storage capacities.
During the mat formation stage of the insulation board process,
the stock is dewatered to a consistency of approximately 40 to 50
percent. Subsequently, in the dryer, the mat is dried to less
than 5 percent moisture.
The water produced by the dewatering of stock at any stage of the
process is usually recycled to be used as stock dilution water at
another stage of the process. However, for reasons discussed in
Section VII, Control and Treatment Technology, there is a need to
bleed-off a considerable quantity of excess process water. In
167
-------
most cases the bulk of the total waste water produced by an
insulation board plant will consist of this water.
Drying - The boards leaving the forming machine with a
consistency of approximately 40 percent are dried to a level
greater than 97 percent in the dryers. This water is evaporated
to the atmosphere and there is no water discharge from the
operation. It is, however, necessary to occasionally clean the
driers to reduce fire danger and maintain proper heat transfer.
This produces a minor waste water stream of about 11,000 1 (3,000
gal) per week in most operations.
Finishing - After the board leaves the dryer, it is usually
sanded and trimmed to size. The dust from the sanding and trim
saws is often controlled by dust collectors of a wet scrubber
type and the recovered dust is recirculated back into the process
for use in making board. The water that is fed into the
scrubbers is sometimes excess process water; however, fresh water
is occasionally used. This water usually returns to the process
with the dust.
Plants that produce coated products such as ceiling tile usually
paint the board after it is sanded and trimmed. Paint
composition will vary with both plant and product; however, all
plants utilize a water based paint. The resulting washup of this
paint produces approximately 400 1 (100 gal) of water per ton of
product which is contributed to the waste .water stream or is
metered to the process white water system. In addition, there
are sometimes imperfect batches of paint mixed. These batches
are occasionally discharged to the waste water stream or metered
to the process white water system.
Broke System - Reject boards and trim are reclaimed as fiber by
recycling. This is done by placing the waste board and trim into
a hydrapulper and producing a fiber slurry that is reused in the
process. While there is need for a large quantity of water in
the hydrapulping operation, the water is normally recycled
process water. There is normally no water discharged from this
operation.
Miscellaneous Water Usage - Other water usage in insulation board
plants include water used for cooling, for seal water in the
vacuum pumps, for screen washing, for fire control, and for
general housekeeping. It is common practice to use cooling water
and seal water as makeup water in the process water system. The
water used for washing screens in the forming and decker areas
usually enters the process water system. Housekeeping water can
vary widely from plant to plant depending on plant operation and
many other factors. A reasonable estimate for housekeeping water
usage is 400 1 per metric ton (100 gal per ton) of machine
production.
168
-------
Waste Water Characterization
Characteristics of insulation board plant waste waters are
essentially the same as those of the water discharged from the
process white water system. This is because the major portion of
the waste water pollutants results from leachable materials from
the wood and additives added during the formation process. The
materials leached from the wood will normally dissolve into
solution in the process white water system. However, if a chip
washer is utilized, a portion of the solubles are dissolved in
this process. A small fraction of the waste water load results
from cleanup operations in the finishing process; however, these
have little influence on any characteristics except suspended
solids. The finishing waste water, in some plants, is metered
back into the process water system with no reported adverse
effects. The characteristics of waste waters produced by a
number of insulation board plants are summarized in Table 44.
Chip Washing - As previously discussed, a chip washer is utilized
by most plants using chips as furnish. The chip washer is used
to remove grit, sand, and other trash which may cause
difficulties in refining, excessive wear of refiner plates, and
impair finished quality of the final product by allowing grit and
sand to be formed into the mat. As was stated above, the primary
source of pollutants at this point is soluble material leached
from the wood. This material would normally dissolve during the
refining and other process operations and become incorporated
into the process white water stream. No accurate characteristics
of chip washer discharge are available; however, it must be noted
that this waste water represents merely a redistribution of
pollutants in the process rather than an effluent requiring
treatment and disposal.
Process White Water - The process white water accounts for over
95 percent of the waste load and flow from an insulation board
plant. It is characterized by high quantities of BOD, COD,
suspended solids, and dissolved solids as shown in Table 44.
The three major factors affecting process waste water quality are
1) the extent of steam pretreatment, 2) the types of product
produced and additives employed, and 3) raw material species.
The major source of dissolved organic material originates from
the raw material. From one to three percent (on a dry weight
basis) of wood is composed of water-soluble sugars stored as
residual sap and, regardless of the type of refining or
pretreatment utilized, these sugars enter the water to form a
major source of BOD and COD. Furthermore, when thermo-mechanical
pulping is employed, not only do the residual sugars enter the
system but there will also occur decomposition products formed by
the hydrolysis of the carbohydrates naturally occurring in the
wood.
Basically, two phenomena occur during steaming. The first of
these is the physically reversible thermo-softening of the
hemicellulose and lignin components of the middle lamella. This
169
-------
TABLE 44 TOTAL PLANT WASTEWATER FROM INSULATION BOARD
Plant
No.
13
7(1)
9
12(1)
6(1)
15 (1)
5(1)
17
4
11(3)
i
10(4)
14
3(J)
Production
KKg/day
109
813
163
322
142
227
291
154
528
457
200
217
353
154
Flow
1/KKg
41,380
14,118
11,564
9,189
50,494
8,346
7,800
14,506
103,910
—
45,487
8,330
9.644
19,956
BOD
Kg/KKg
11.3
11.6
15.1
15.1
27.5
32.3
33.7
33.7
34.7
35.2
39.0
40.9
44.6
COD
Kg/KKg
67.9
49.0
„
20.3
—
62.5
72.4
—
~
1S1.8
94.5
__
88.7
valid data
TS
Kg/KKg
95.9
—
—
—
_.
48.1
—
—
—
278.9
93.9
98.2
—
not
ss
Kg/KKg
52.1
11.8
14.1
4.2
14.5
11.7
3.0
30.0
24.7
235.0
10.5
25.7
52.3
OS
Kg/KKg
45.0
20.4
_
—
—
36.3
8.0
—
—
—
83.4
—
—
available
(l) Analysis taken after preliminary clarification
(2) Forming machine production
(3) Plant utilizes bagasse
(4) Values do not represent present conditions due to experimental
changes in water systems
(5) Represents 70-90 percent of total load
170
-------
effect does not break down the cellulose or hemicellulose into
water soluble substances.
The second effect consists of time dependent chemical reactions
in which hemicellulose undergoes hydrolys is, and produces
oligosaccharides (short chained, water soluble wood sugars,
including disaccharides). In addition, hydrolysis of the acetyl
groups form acetic acid. The resulting lowered pH causes an
increase in the rate of hydrolysis. Thus, the reactions can be
said to be autocatalytic. For this reason, the reaction rates
are difficult to calculate. However, estimations have been made
that the reaction rates double with an increase in temperature of
eight to ten degrees Celsius. As can be expected and as shown in
Figure 40 there is a higher BOD in a plant's waste water when the
plant utilizes steaming. This results primarily from an increase
in the dissolved substances entering the water. There is,
however, not a direct relationship between the amount of BOD and
the amount of dissolved solids entering the system. In general,
at lower temperatures (pressures), where higher yields are found,
there is a higher ratio of BOD to dissolved solids because of a
higher percentage of low molecular weight material entering the
waste water. This is illustrated in Figure 41. It can be
concluded that with increased steam pressure there is a higher
proportion of long chain, high molecular weight carbohydrates
entering the water. These compounds are not easily
biodegradable.
Plants 1, 9, 12, 13, and 16 in Table 44 all report little or no
steaming of furnish and other than plant 4, which will be
discussed later, the remainder of the plants steam a major
portion of furnish.
The exact nature and percentage of materials dissolved in the
water vary with species, i.e., as discussed earlier in this
document, hardwoods contain a greater percentage of potentially
soluble material than do softwoods. Nevertheless, as indicated
in Table 45, using steam factors from Figure 40, the effect of
species on waste water load is of secondary importance when
compared to the degree of steaming to which the chips are
subjected and to the extent of hardboard production.
An analysis of the data in Table 45 shows a correlation
coefficient of 0.79 between the steam factor and BOD load data.
Neglecting the data from plant 10, a correlation coefficient of
0.73 is observed between hardboard production of plants with high
steam factors and BOD load. The fact that species type has
relatively little effect on pollutant generation, or that what
effect it does have is masked by the more significant effects of
steaming and hardboard production, is shown by a correlation
coefficient between the utilization of hardwood and BOD load of
less than 0.1 for the types of plants that utilize little or no
steaming and for plants with high steam factors.
While a large portion of the BOD in the process waste water is a
result of organics leaching from the wood, a significant portion
171
-------
60-
40-
TOTAL B007 IN kg
02/TON DRY CHIPS
—\ 1 1 1 1 1 1 1 1 1—
04 6 6 10 12
PRE-HEATING PRESSURE (atm.g.)
FIGURE 40 VARIATION OF BOD WITH PRE-HEATING PRESSURE
172
-------
0.70-
0.60-
0.50-
BODr
g O./g DISSOLVED MATERIAL
PLANT B
PLANT A
92
94
% YIELD
96
FIGURE 41 VARIATION OF THE RATIO OF BOD/DISSOLVED SOLIDS WITH YIELD
173
-------
l&ELE 45
EFFECT OF HARDWOOD, STEAMING, AND HARDBOARD
PRODUCTION ON THE BOD LOAD FROM
INSULATION BOARD PLANTS
Plant Hardwood
No. Percent Furnish
16
13
7
9
12
6
15
17
5
4
1
10*
14
3
10
0
15
0
22
0
56
100
15
92
100
92
7
0
Steam Hardboard BOD
Factor Percent Production KgfKKg
2.5
2.7
2.5
3.6
3.8
6.0
6.5
6.2
9.0
4.0
6.0
6.2
6.3
—
0
0
0
0
Q
0
0
0
27
44
60
0
26
47
6.5
11.2
11.6
15.1
15.1
27.6
32.2
33.6
33.6
3L7
39.0
40.5
44.6
NG
*Values do not represent present conditions due to experimental
changes in water systems.
17«*
-------
results from additives. Additives vary in both type and quantity
according to the operational preferences of the plant to some
extent, but primarily to the type of product being produced. An
unpublished report prepared by the Acoustical and Insulating
Materials Association indicates a variation in waste load with
variation in additives; however, this is difficult to quantify.
receive various
up to 25 percent
The three basic types of product produced by insulation board
plants, sheathing, finished tile (ceiling tile, etc.), and
hardboard (including medium density siding)
amounts of additives. Sheathing contains
additives which include asphalt, alum, starch, and size (either
wax or resin). Finished tile contains up to 10 percent additives
which are the same as used in sheathing, except no asphalt is
used. Hardboard contains up to 30 percent additives including
organic resins, as well as emulsions and tempering agents such as
tall oil.
Total retention of these additives would be advantageous from
both a production cost as well as waste water standpoint, but is
not currently achievable. Therefore, the process waste water
will contain not only leachates from the wood and fugitive fiber,
but also the portion of the additives not retained in the
product.
The primary effect of product type occurs with the production of
hardboard in an insulation board plant. Hardboard often requires
higher amounts of additives, but it also requires a pulp of a
higher quality than does insulation board and thus more fiber
preparation may be necessary. For these reasons, the hardboard
producing plants will have a greater waste water load than plants
which do not produce hardboard. This again is shown in Table 45.
Plants 1, 3, 5, and 14 all utilize steaming in fiber preparation
and also produce hardboard; therefore, the se piants have
characteristically higher waste water loads. Plant 4, which also
produces hardboard, utilizes little or no steaming of furnish.
For this reason, the effluent from plant 4 is similar to the
effluents from plants that steam chips but do not produce
hardboard.
Model Plants
As discussed in Section IV, the subcategory of insulation board
production has been further subcategorized into two portions.
Subcategory I consists of plants that do little or no steaming of
furnish. These plants are 7, 9, 12, 13, and 16. Subcategory II
includes those plants that steam the furnish or plants that
produce hardboard at the same facility. These include plant
numbers 1, 3, 4, 5, 6, 10, 14, 15, and 17 as shown in Table 44.
There are wide variations of production rates within each
category; however, there is little or no correlation between
production rates and subcategories. Since the average production
rate for all plants listed in Table 44 is 288 metric tons per day
(318 tons per day), a production rate of 270 metric tons per day
175
-------
(300 tons per day) was selected as the production
model plants.
rate for all
An analysis of the data presented in Table 44 shows there is a
wide range of waste water flow independent of subcategories.
Waste water flow is not directly related to the organic waste
water load discharged but to individual plant operation and water
utilization practices. A flow of 12,500 1 per metric ton (3,000
gal per ton) was judged to be representative of plants with good
inplant control. Therefore, a flow of 12,500 1 per metric ton
(3,000 gal per ton) was selected as the flow from the model
plants for each subcategory.
Table 44 also shows a wide range of suspended solids discharged
independently of subcategories. The suspended solids
concentrations in the waste water discharged from an insulation
board plant depend on equipment utilized to remove suspended
solids from the waste water stream possibly prior to its reuse.
The model plant for each subcategory is assumed to utilize a
primary clarifier for suspended solids removal. Primary
clarification is an effective and common method of suspended
solids removal in the insulation board industry. Data in Table
U4 show that the suspended solids in the effluent from primary
clarifiers in all three subcategories can be expected to average
10 Kilograms per metric ton (20 pounds per ton).
The model plants are assumed to have adequate sludge handling
facilities since this is the case for most existing plants.
Based on limited data, it was assumed that the waste sludge from
primary clarifiers is 10 kilograms per metric ton (20 pounds per
ton) at 3.0 percent consistency.
The principal variation in waste water quality between
subcategories occurs in regard to the BOD loads. The BOD loads
for subcategory I and II were selected to be 12.5 kilograms per
metric ton (25 pounds per ton), and 37.5 kilograms per metric ton
(75 pounds per ton), respectively.
As shown in Table 44, the BOD loads in subcategory I range from
6.5 kilograms per metric ton to 15 kilograms per metric ton (13
pounds per ton to 30 pounds per ton). Plant 16, which has a
discharge of 6.5 kilograms per metric ton (13 pounds per ton),
soaks its wood before grinding; however. This operation will be
phased out by the end of 1974. The soaking liquor removes a
portion of the BOD load which is not reported as part of the 6.5
kilograms per metric ton (13 pounds per ton). This is assumed to
be approximately 25 percent of the total plant discharge. An
average of the adjusted BOD load for the subcategory. The plants
in this subcategory exercise approximately equal degrees of
inplant control methods.
The BOD of 37.5 kilograms per metric ton (75 pounds per ton) of
subcategory II is considered reasonable based on interpretation
of the data presented in Table 44. Waste loads from these plants
range from 27.5 to 44.6 kilograms per metric ton (55 to 89 pounds
176
-------
per ton). Although little data is available, plant 10, which
reports a waste load to 40.5 kilograms per metric ton (81 pounds
per ton), appears to have reduced its waste load significantly at
this time. Based on current experimental modifications at this
plant, it is projected that the plant can reduce its waste load
to 27.5 kilograms per metric ton (55 pounds per ton) or less. An
average of the plants in this subcategory is approximately 37
kilograms per metric ton (74 pounds per ton) ; therefore, the BOD
load for this subcategory was assumed to be 37 kilograms per
metric ton (74 pounds per ton) .
A summary of the waste water characteristics for model plants
all subcategories is presented below.
of
II
12,500
12,500
Production
kkg/day
270
270
BOD
kq/kkg
12.5
37.5
SS
kq/kkq
10
10
It should be noted that the presented flows and loads occur after
a primary clarifier. The loads and flows given do not include
cooling water, boiler blowdown, roof runoff, yard runoff, or
waters from raw material handling and storage operations.
PARTICLEBOARD
Specific Water Uses
There is little water used in the manufacturing of particleboard
itself. Water usage for raw materials handling is typical of the
timber products industries and is discussed elsewhere in this
document. The water use within a typical plant may consist of
that used for cleaning blenders, rinsing additive storage tanks,
caul cooling sprays, mat sprays, fire suppression water, cooling
water, water used in scrubbers for air emissions control, and
water used in miscellaneous operations. The total quantity of
waste water flow, excluding cooling water, from a particleboard
plant, according to all collected data, may range from less than
190 Ipd (50 gal per day) to as much as 320,000 Ipd (86,000 gal
per day), with little correlation in plant production. Cooling
water requirements may run from 150 to 2,300 cu m per day (0.04
to 0.60 mgd), but rarely exceed 1,100 cu m per day (0.3 mgd).
Table 46 itemizes waste water flows from particleboard plants.
Data were obtained by questionnaires sent out by the National
Particleboard Association and samples collected from several
plants during this study.
Blender Wash: Blender cleaning is necessary because of the fact
that during the operation of the blender there is a buildup of
resin and wood particles on the interior of the machine which
causes increased friction and eventual binding of the moving
177
-------
TABLE 46
PARTICLEBOARD PLANT PROCESS WATER AND COOLING WATER FLOW RATES
Plant
Number
J5
i
29
28
25
2
23
3
16
4
3.1
11
P
6
20
9
Wastewater
Product! on Di scharge
(kkg/day) (I/day)
87_ 189
J8
54
136
136 2277.
140
261
272 1,097,6506,
272 15,140
295 12,3017
297 327,213
317 45421
317
336
356 3785
363
Cooling
Water
Discharge
(I/day)
J90.764
151,400
187,887
2,180,1607_
1,362.6004.
55,6584
to
416,350
163,512
to
464,798
654,048
545,0401
11,355
189,250
10,9037
Blender House- Press
Washout keeping Pi t
(I/day) (I/day) (I/day)
1S9
189
5681
151
57 802
1893i
42735 1325
to
9463
54,504 218,016 54,693
189 76
18937.
J325
3785
227
to
341
Storage
Tank Wash
Waters
(Vday)
761
76
303
15 14
189
363
43,603
7570 18,9252
18,9253.1/change
178
-------
TABLE 46
PARTICLEBOARD PLANT PROCESS WATER AND COOLING WATER FLOW RATES
(Continued)
Plant
Number
30
12
26
27
14
19
10
8
32
Wastewater
Producti on D1 scharge
(kkg/day) (I/day)
381
392
431
449
499 83277,
635
726
1361
Cooling
Water Blender House-
Discharge Washout keeping
0/day) (I/day) (I/day)
253,595
1,627,550
98,0324
2,. 180, 160
2,;iSO,X60 7570
1,771,380
Dry Clean
454,200 IB, 925
Storage
Press Tank Wash
Pi t Waters
(I/day) (I/day)
21,953
757
28393. 1/wk
NOTE: No available data for plant numbers not listed,
l) once per week
2) once per 3-months
3) frequency varies
4) recycled
5) includes blender wash
6} scrubber effluent
7) estimated
179
-------
parts of the blender, increased wear on the motors, and a
decrease in blender capacity. Also the residue buildup on the
inside of the blender may break loose and become formed into the
finished board. This may result in resin spots which are
considered by the industry to be a serious quality problem. This
residue must be removed periodically. The volume of wash water
used depends on (1) the frequency of cleaning, and (2) whether
the cleaning operation is preceded by manual scraping of the
blender. The frequency of the blender cleanup operation varies
from plant to plant. Blenders may be cleaned as infrequently as
once a week or as often as four times a day depending on the type
of blender being used as well as the size of the wood particles
and the tack (ability to adhere) of the resin being added.
Certain types of blenders are equipped with a cooling jacket
which reduces the frequency of washing because the resins
utilized are thermo-setting and a reduction in temperature inside
the blender will significantly reduce the amount of buildup.
There is a wide variation in buildup in actual field conditions.
No definitive explanation for this variability in buildup is
available. It has been noted in the field that particles of
smaller size cause an increase in the rate of buildup on the
interior of a blender. While no definitive studies have been
conducted in this area, the phenomenon is most likely related to
the surface area, volume ratio of the particles.
Blenders, although usually cleaned with water, are sometimes
cleaned by manual scraping followed by the use.of steam to remove
the remainder of the waste. This method requires approximately
45 1 (12 gal) of water per washing operation. When water is used
to wash out blenders, the resulting quantity of water required is
approximately 400 1 (100 gal) per wash. A discussion of factors
for choosing wet or dry blender cleaning can be found in Section
VII of this report, when phenolic resins are used, they may be
added in a refiner rather than in a blender; however, the
refiners must also be cleaned and a waste stream of a similar
volume results.
In a particleboard plant there is need occasionally to clean
additive storage tanks to remove a buildup of residue. The
amount of water used varies widely, approximately from 75 to
19,000 1 (20 to 5,000 gal) per washing operation, but usually
does not exceed 2,000 1 (500 gal) per wash. These tanks are
washed infrequently, usually once every three months for resin
storage tanks and once a year for wax emulsion storage tanks.
Some plants find the need to wash tanks more frequently for
reasons relating to resin storage life and ambient temperatures.
Also, washing is required more frequently when different types of
resins used for different products must be stored in the same
tank.
Caul Cooling Water - Approximately half the particleboard plants
in the U. S. utilize cauls for forming the mat or transporting
the mat into the press and the finished board out of the press.
During the pressing cycle, the cauls may become quite warm and
180
-------
must be cooled before being reused. This is usually accomplished
by spraying a fine mist of water onto the cauls. There is
usually no discharge from this point, and, if discharge does
occur, it normally does not exceed 3.8 to 7.6 1 (1 to 2 gal) per
minute.
Mat Spray - In order to improve the final product, it is
sometimes advantageous to slightly moisten the mat before it is
pressed. This is done by a spray in a similar manner as caul
cooling, and usually results in no discharge.
Fire Suppression Water - An inherent problem in the production of
particleboard is that as a result of the wood particles being
transported in a dry state, they are subject to fire and
explosion. The interior of a particleboard plant can easily
become coated with dry particles which are ignitable by an
electrical spark or excessively hot press or other equipment.
Most frequently fires start in a refiner or flaker and quickly
spread throughout the particle conveying system. Fires are not
scheduled and their frequency varies from mill to mill depending
on the degree of particle preparation carried out and other
factors. Historically, major fires occur from two to twelve
times a year. Most mills have elaborate fire fighting systems
which use massive quantities of water to rapidly extinguish
fires. The quantity of water used will vary with the extent and
duration of the fire. In addition, there are sometimes minor
fires, occurring as often as once or twice a day but more
commonly once or twice a week, which require relatively small
quantities of water for control.
Cooling Water - The largest volume of water used in a
particleboard mill is cooling water for various inplant equipment
such as refiners, air compressors, hydraulic systems, press
platens, resin tanks, blenders, and other machinery. As
presented in Table 40, typical volumes vary from 150 cu m per day
(O.OU million gal per day) to over 7,000 cu m per day (2.0
million gal per day).
Scrubbers - Air pollution from particleboard mills is a major
environmental concern. One method of air pollution control in
the particleboard industry is the use of wet scrubbers. Water
usage for scrubbing will vary depending on the individual
scrubber design. As discussed in Section VII, all of the waste
water from wet scrubbers can be recycled by use of settling ponds
with makeup being added to replace that evaporated. Excess
solids buildup in the settling ponds is normally hauled to
landfill areas as necessary. As most scrubbers in the
particleboard industry can be operated without a waste water
discharge, they are not considered to be a significant waste
water source.
Miscellaneous Operations - There are several miscellaneous
operations in a particleboard mill that result in waste water
discharges
per plant.
totaling approximately 4,000 Ipd (1,000 gal per day)
These discharges consist primarily of water and oil
181
-------
formed in the press pit because of leaking of the press hydraulic
system and water used for general plant cleanup. Volumes
reported from the press pit vary from essentially zero to 5^,700
Ipd (ia,45Q gal per day); however, a flow of 1,000 Ipd (300 gal
per day) or less is judged to be typical. The plants reporting
higher volumes usually rinse the press pit with water. Although
many plants are cleaned with vacuum cleaners or other dry
devices, some plants feel the need to wash these areas with water
for the purpose of fire prevention. If this is done, there will
be an increased water discharge of approximately 8,000 Ipd(2,000
gal per day) from the plant.
Another water discharge may result from the condensation of steam
coming into contact with the cold metal of a pressurized refiner
during start up. This is an intermittent flow that will cease
once the refinery reaches operating temperatures. The quantity
is estimated to be less than 150 1
-------
TABLE 47
TOTAL PARTICLEBOARD PLANT RAW WASTEWATER DISCHARGE
Plant Flow Color Temp. BOD COD
No. (I/day) pH (units) (°C) (mg/1) (mg/1)
4 12,491 7.2 380
to
12.0
1
31 327,403
t— fc
OD
CO
12 264,950* 6.6 15
32 6.2 50
to
7.6
US
to
44
28 134 320
to
260
300 H5
22 6
to to
24 35
TS SS DS
(mg/1) (mg/1) Ong/1)
35
to
260
134
to
259
68 2i 47
30
on &
P04 Phenols Grease TN ON
(mgTl) (mg/1) (mg/1) (mq/1) (mg/1)
17
to
18
0.7 18.5 • 135
0 4.1
1
td
50
*Total flow Includes wastewater and some cooling water.
-------
TABLE 48
WASTE WATER ANALYSIS BY STREAM
h-l
oo
-c-
Source
Blender
Wash
Urea Resin
Tank Wash
Press
Pit
Plant
No.
24
6
4
11
3
5
Flow
(I/day)
379
V
1325
1514
189
1893
95
Color
pH (units)
6.4_
7.0 433
7.7
262
7.4
7.3
Turb. BODc
(J.T.U.) (mg/T;
60
5 31 ,500
750 39,300
500
150
COD
1 (mg/1)
357
9,523
18,200
13,200
414
TS
.(mg/1)
373
4,385
38,234
5,638
697
SS
(mg/1
98
1,650
3,335
155
225
DS
) (mg/1)
275
2,735
34,899
5,483
472
ST.S P04
(mg/1) (mg?l)
<1 /
1.67
15
6.75
<1
Phenols TN KN
(mg/1) (mg/1) (mg/1)
0.75 18.3
1340
87.4 41,278
35 52.2
<.005 64.5
VS P TOC
(mg/1) (mg/1) (mg/1)
34,534
5,079 3.14
1 .85 148
-------
will contain quantities of floatable wax. The waters from
washing resin tanks will contain quantities of nitrogen or
phenols, depending on whether urea or phenolic resins are
utilized.
Cooling Water - Cooling water is usually uncontaminated and is
characterized by having an increased temperature that will vary
with the type of equipment being cooled. However, in some cases,
mills handling their cooling water in open trenches allow the
cooling water to become contaminated with wood fibers, additives,
or oil. Generally, it is considered that proper process
management allows cooling water to be a noncontact,
uncontaminated stream.
Miscellaneous Operations - The waste stream generated by general
plant cleanup or waters pumped from the press pit vary widely in
degree of contamination. The water from plant cleanup will
normally contain wood particles as well as some oils or resins
which have been spilled. The amounts of these substances in the
waste water stream will vary considerably with time. The waste
stream from the press pit is composed of liquids from the
hydraulic system of the press as well as from steam lines and
will contain a large amount of fugitive particles. Character-
istics of this stream vary. Results of analyses conducted for
one plant are presented in Table 48.
Model Plant
Based on the values presented in Table 46, a typical
particleboard plant discharges on an intermittent basis 11,000 1
(3,000 gal) per day of contaminated waste water. It has a
production of 270 metric tons (300 tons) per day. The 22,000 1
(3,000 gal) of waste water consist of 7,200 1 (2,000 gal) per day
of housekeeping water, i.e., water used for general plant
cleanup; 1,900 1 (500 gal) per day of resin blender wash water;
and an additional 1,900 1 (500 gal) per day consisting of
miscellaneous flows including periodic washdown of storage tanks,
pressurized refiner start-up, and water from the press pit. It
is felt that because no discharge is a feasible alternative, the
flow is the primary factor involved in a consideration of waste
water treatment schemes. The model plant utilizes planer
shavings or chips as a basic raw material. It does not wash the
raw material before utilizing it in the process.
The model plant is considered to be typical of the particleboard
industry at this time. However, the model plant in the future
may include both a chip washer and a scrubber for air emissions
control.
FINISHING OPERATIONS
There are two distinct classifications of finishing materials
used in the factory finishing of wood products. Liquid finishing
materials include water and solvent based sealers, stains, dyes,
primers, fillers, base or ground coatings, printing inks, and top
185
-------
coatings. Overlaying materials include resin-impregnated papers,
special plastic films, and metal foils. The overlaying of
particleboard with veneers and hardboard is also practiced to a
limited extent.
The water used in finishing operations primarily consists of
makeup water and wash water associated with the use of water-
reducible coatings and adhesives and in surface cleaning
operations practiced at some plants as an initial step in the
finishing operation. As reported by Tomsu, the use of water-base
coatings has been associated with the increasingly stringent
regulatory limits on solvent emissions from finishing lines.
Water-base fillers are used on particleboard, hardboard, and
open-grained plywood. Water thinned sealers, ground coats, and
clear top coats are also used to some extent. Some finishing
plants prepare the surface of the substrate for finishing by
machine washing with water and a mild detergent. However, such
an operation produces no waste water as all Wash water is used in
the makeup of the cleaning solution.
The only sources of waste water from finishing operations result
from the washing of equipment associated with the use of water-
reducible coatings and water soluble adhesives. Such equipment
includes the various types of applicating machines discussed in
Section III and the vats or barrels in which the coating
materials or adhesives are mixed and stored prior to application.
Table U9 shows the total volumes of waste water generated at
several finishing plants. Also given in this table are the types
of finished products produced, annual production rates, and the
types of water reducible materials applied at each plant. It can
be seen that the volumes of waste water generated vary
considerably from plant to plant. These variations are chiefly
attributable to the different manners in which the equipment is
washed. For instance, some plants may use 90 to 115 1 (25 to 30
gal) of water or more to wash down one roll coater used in
applying a water base coating material, while another plant may
use less than 20 1 (5 gal) of water to wash down the same type of
machine used to apply a similar type of material.
Because of the wide variety of finished products produced, types
of coatings applied, and methods of application and drying
employed, both water and solvent base coating materials are
custom formulated for each application. The constituents of
these materials are widely varied throughout the industry and in
many cases even at the individual finishing plant level where
custom formulations are freqently made. Generally, as reported
by Leary, the market requirement influences the type of chemical
coating system applied to the surface of any finished product.
Because of such extreme variations, no list of typical
ingredients of coating materials used in wood finishing is
available, and characterization of the waste waters generated in
the use of such materials is not possible on an industry wide
basis. Characterization of waste waters from such finishing
186
-------
TABLE 49
WASTE WATER GENERATION FROM FINISHING PLANTS
CO
Type of Finished
Plant Products Produced
A Prefinlshed Wall
Paneling and Vinyl
Overlaid Hardwood
Plywood
B Prefinlshed Wall
Paneling
C Prefinlshed Wall
Paneling
D Prefinlshed Wall
Paneling
E Vinyl Overlaid
Hardboard Panels
F Prefinlshed Wall
Paneling
G Prefinlshed Wall
Paneling
H Preflnished Wall
Paneling
Aluminum Overlaid
Softwood Plywood
Exterior Siding
Annual Production
of Finished Products
(Millions of Square Meters)
12
11
6
2
11
10
Applicators of
Water-Reducible
Finishing Materials
1 Groove Striper
1 Adhesive Spreader
(Direct Roll)
2 Filler Applicators
(Reverse Roll)
2 Groove Stripers
1 Grain Printer
(2 Rolls)
1 Tcp Coater (Direct
Roll)
l Sealter Coater (Direct
Roll)
l Adhesive Spreader
(Direct Roll)
l Sealer Coater (Direct
Roll)
3 Sealer Coaters (Direct
Roll)
i Sealer Coater (Direct
Roll)
l Filler Coater (Reverse
Roll) .
l Arfieslve Spreader
2 Spray Booths
Volumes of
Wastewater Generated*
260
1,360
75
130
75
11 0
I/O
760
450
*L1ters
-------
operations would only be possible on an individual plant basis.
Table 50 shows the results of the chemical analyses of several
water base coatings and the wash waters generated from their use.
However, these materials are not typical of all waterbase coating
materials used in finishing operations and are presented only as
an indication of possible waste water characteristics.
As reported by Conner, various metals may find their way into any
coating material. Additives of various types such as those which
are incorporated into a coating material as stabilizers for such
purposes as to prevent biological contamination of the material
during its shelf-life, often contain mercury, although at the
present time efforts are being made by the paint and coating
industry to develop additives of non-mercuric types. Pigments
incorporated into a coating material to provide color, commonly
contain lead or cadmium or other materials.
The most extensive study of waste water from paints and coatings
is currently being made for EPA by Southern Research Institute.
The findings of this study with respect to waste water
characteristics of waste water from water-base paints and
coatings would be most representative of the waste waters
generated from finishing operations in the timber products
processing industry which involve the use of such materials.
Adhesives used in overlaying various sheet materials include
plastic and vinyl films, medium density impregnated papers, and
metal foils. The most commonly used adhesives for overlaying
special plastic films are polyvinyl acetate water-emulsion
adhesives, solvent-type elastomeric adhesives, modified phenolic
films, special epoxy-resin formulations, and various contact-type
adhesives. The resin—impregnated papers requiring additional
adhesive bonding are commonly bonded to the wood substrate by
phenolic and modified phenolic resin glues. Aluminum foil
overlays are commonly applied with modified phenolic resin film
glues, resorcinol resins, and rubber-base contact cements. As
reported by Brumbaugh, phenol and urea resin glues are the most
common adhesives used in overlaying veneers and hardboard onto
particleboard. Of these various adhesives, only the polyvinyl
acetate-water emulsions, the phenolic and urea resins, and the
resorcinol resins are water soluble and would constitute a source
of waste water in the washing of equipment associated with their
use. Water-soluble adhesive applicating machines employed in
overlaying operations are usually washed at the end of each run
and require about 75 1 (20 gal) of water for each washing.
Since most overlayed wood products are usually produced as
specialty items in the larger finishing plants, and are not
usually produced on a full scale, continuous production basis,
volumes of waste water generated from such operations would
seldom exceed 75 Ipd (20 gal per day) from any single finishing
plant. The characteristics of these waste waters would be
similar to those described previously for adhesive wash waters
generated in fabricating operations. The chemical analysis of a
188
-------
TABLE 50
CHEMICAL ANALYSIS OF WATER BASE MATERIALS
Total Total Total
To tal Total
Material
Water base sealer
Washwater
Water base sealer
Washwater
Water base sealer
Washwater
h-*
g Waterbase filler
Washwater
Total
Solids
(mg/D
267,805
1,765
543,160
46,710
675,530
28,300
1,203,720
65,000
Suspended
Solids
(mg/1)
56,465
335
345,490
43,022
538,530
25,537
1,160,290
60,2iO
Dissolved
Solids
(mg/D
211,340
1,430
197,670
3,688
137,000
2,763
43,430
4,790
Volatile
Solids
(mg/D
196,866
1,405
446,590
40,880
203,970
7,510
223,720
27,000
Sus pended
Sol Ids
(mg/1)
40,755
141
318,590
37,407
146,370
5,420
154,150
22,717
Dissolve
Solids
(mg/D
156,111
1,264
128,000
3,473
57,600
2,090
69,570
4,283
d
COD
(mg/D
306,740
8,428
512,462
51 ,169
305,760
26,264
226,968
51,156
P04t Nt
(mST\) (mg/D
6351.0 469.56
191.9 123.31
3500.0 435.44
504.1 65.52
137.8 89.82
86.5 6.33
113.5 579.44
52.7 81.62
Phenols
(mg/1)
3699.4
^04.0
329.4
92.8
4975.4
212.1
361.3
213.8
Water Soluble
adhesives
Washwater
607,771 88,098 519,673 591,167 77,566 513,601 807,128 94.6 77.25 2678.3
253,502 250,492 3,OlO 241,342 238,656 2,686 245,000 1216.2 8.84 3191.1
-------
water soluble adhesive used in a vinyl overlaying operation and
the waste water generated from its use is presented in Table 50.
Figure U2 shows a process flow diagram for the production of
printed grain, prefinished wall paneling and shows the amounts of
waste water generated from such an operation. Although this may
not be typical of any particular plant, it should serve here to
illustrate typical sources and volumes of waste water that might
be generated from such a plant.
Model Plant
Although finishing operations are carried out in many different
types of plants, producing a wide variety of types of finished
products, the volumes of waste water generated from finishing
plants generally fall into the range of 75 to 1,100 Ipd (20 to
300 gal per day). The typical finishing plant to be developed
for the purposes for this study is a plant producing prefinished
wall paneling with a total waste water generation of 750 Ipd (200
gal per day) resulting from the washing of equipment associated
with the use of water-base finishing materials. The typical
plant is assumed to consist of the following:
1. Two identical finishing lines similar to that shown in
Figure U2.
2. Both lines operate on a 24 hour per day, 5 days per week
basis.
3. Each line consists of three water-base material appli-
cating machines.
U. Annual production of prefinished paneling is equal to 10
million sq m on a 6.35 mm basis (107.6 million sq ft on a
0.25 in basis) .
Typically, each water-base material applicating machine would be
washed once each day requiring 75 1 (20 gal) of water per wash.
Wash water from machine wash down would then consist of 450 1
(120 gal) per day. Material storage and mixing vats require 300
1 (80 gal) of wash water per day. The total volume of waste
water generated at the typical plant would then be 750 Ipd (200
gal per day) .
190
-------
FEED
HARDWOOD
PLYWOOD
PANELS
V- GROOVE
CUTTER
MACHINE
WASH WATER
75 LITERS/DAY
MACHINE
WASHWATER
T5 LITERS/DAY
CO
MACHINE
WASHWATER
79 LITERS/DAY
PACKAGING AND
SHIPPING
(EXISTING 2-LINES)
VAT
WASHWATER
SCO LITERS/DAY
TOTAL MACHINE WASHWATER • 229 I/day
MACHINE WASHWATER • 490 I/day
VAT WASHWATER • 900 I/doy
TOTAL* 799
FIGURE 42 WASTEWATER PRODUCTION IN A PREFINISHED PANEL PLANT
-------
-------
SECTION VI
POLLUTANT PARAMETERS
Presented below is a discussion of pollutants and pollutant
parameters that may be present in process waters in the portion
of the timber products processing industry that is the subject of
this proposed effluent guidelines and standards development
document.
Certain of these parameters are common to all the subcategories
covered by this document, although the concentrations in the
process water and the absolute amounts generated per unit of
production vary considerably among the subcategories.
Review of published information. Refuse Act Permit applications,
industry data, and information generated during the survey and
analysis phase of this effluent guidelines development program
determined that the following pollutants or pollutant parameters
may be common to all of the subcategories:
Biochemical Oxygen Demand (BOD5)
Chemical Oxygen Demand
Phenols
Oil and Grease
pH
Temperature
Dissolved Solids
Total Suspended Solids
Phosphorus
Ammonia
Copper
Chromium
Arsenic
Zinc
Flourides
The above listed pollutants or pollutant parameters are, of
course, not present in process water from all the subcategories
for which effluent guidelines and standards are presented in this
document. Their presence depends on a number of factors, such as
processing method, raw materials used, and chemicals added to the
process. x
Following is a discussion of the significant pollutants and
pollutant parameters.
Biochemical Oxygen Demand (BODS)
Biochemical oxygen demand (BOD) is a measure of the oxygen
consuming capabilities of organic matter. The BOD does not in
itself cause direct harm to a water system, but it does exert an
indirect effect by depressing the oxygen content of the water.
Sewage and other organic effluents during their processes of
193
-------
decomposition exert a BOD, which can have a catastrophic effect
on the ecosystem by depleting the oxygen supply. Conditions are
reached frequently where all of the oxygen is used and the
continuing decay process causes the production of noxious gases
such as hydrogen sulfide and methane. Water with a high BOD
indicates the presence of decomposing organic matter and
subsequent high bacterial counts that degrade its quality and
potential uses.
Dissolved oxygen (DO) is a water quality constituent that, in
appropriate concentrations, is essential not only to keep
organisms living but also to sustain species reproduction, vigor,
and the development of populations. Organisms undergo stress at
reduced DO concentrations that make them less competitive and
able to sustain their species within the aquatic environment.
For example, reduced DO concentrations have been shown to
interfere with fish population through delayed hatching of eggs,
reduced size and vigor of embryos, production of deformities in
young, interference with food digestion, acceleration of blood
clotting, decreased tolerance to certain toxicants, reduced food
efficiency and growth rate, and reduced maximum sustained
swimming speed. Fish food organisms are likewise affected
adversely in conditions with suppressed DO. Since all aerobic
aquatic organisms need a certain amount of oxygen, the
consequences of total lack of dissolved oxygen due to a high BOD
can kill all inhabitants of the affected area.
If a high BOD is present, the quality of the water is usually
visually degraded by the presence of decomposing materials and
algae blooms due to the uptake of degraded materials that form
the foodstuffs of the algal populations.
Phenols
Phenols and phenolic wastes are derived from petroleum, coke, and
chemical industries; wood distillation; and domestic and animal
wastes. Many phenolic compounds are more toxic than pure phenol;
their toxicity varies with the combinations and general nature of
total wastes. The effect of combinations of different phenolic
compounds is cumulative.
Phenols and phenolic compounds are both acutely and chronically
toxic to fish and other aquatic animals. Also, chlorophenols
produce an unpleasant taste in fish flesh that destroys their
recreational and commercial value.
It is necessary to limit phenolic compounds in raw water used for
drinking water supplies, as conventional treatment methods used
by water supply facilities do not remove phenols. The ingestion
of concentrated solutions of phenols will result in severe pain,
renal irritation, shock and possibly death.
Phenols also reduce the utility of water for certain industrial
uses, notably food and beverage processing, where it creates
unpleasant tastes and odors in the product.
19J*
-------
Oil and Grease
Oil and grease exhibit an oxygen demand. Oil emulsions may
adhere to the gills of fish or coat and destroy algae or other
plankton. Deposition of oil in the bottom sediments can serve to
exhibit normal benthic growths, thus interrupting the aquatic
food chain, soluble and emulsified material ingested by fish may
taint the flavor of the fish flesh. Water soluble components may
exert toxic action on fish. Floating oil may reduce the re-
aeration of the water surface and in conjunction with emulsified
oil may interfere with photosynthesis. Water insoluble
components damage the plumage and coats of water animals and
fowls. Oil and grease in a water can result in the formation of
objectionable surface slicks preventing the full aesthetic
enjoyment of the water.
Oil spills can damage the surface of boats and can destroy the
aesthetic characteristics of beaches and shorelines.
ESf Acidity and Alkalinity
Acidity and alkalinity are reciprocal terms. Acidity is produced
by substances that yield hydrogen ions upon hydrolysis and
alkalinity is produced by substances that yield hydroxyl ions.
The terms "total acidity" and "total alkalinity" are often used
to express the buffering capacity of a solution. Acidity in
natural waters is caused by carbon dioxide, mineral acids, weakly
dissociated acids, and the salts of strong acids and weak bases.
Alkalinity is caused by strong bases and the salts of strong
alkalies and weak acids.
The term pH is a logarithmic expression of the concentration of
hydrogen ions. At a pH of 7, the hydrogen and hydroxyl ion
concentrations are essentially equal and the water is neutral.
Lower pH values indicate acidity while higher values indicate
alkalinity. The relationship between pH and acidity or
alkalinity is not necessarily linear or direct.
Waters with a pH below 6.0 are corrosive to water works
structures, distribution lines, and household plumbing fixtures
and can thus add such constituents to drinking water as iron,
copper, zinc, cadmium and lead. The hydrogen ion concentration
can affect the "taste" of the water. At a low pH water tastes
"sour." The bactericidal effect of chlorine is weakened as the pH
increases, and it is advantageous to keep the pH close to 7.
This is very significant for providing safe drinking water.
Extremes of pH or rapid pH changes can exert stress conditions or
kill aquatic life outright. Dead fish, associated algal blooms,
and foul stenches are aesthetic liabilities of any waterway.
Even moderate changes from "acceptable" criteria limits of pH are
deleterious to some species. The relative toxicity to aquatic
life of many materials is increased by changes in the water pH.
Metalocyanide complexes can increase a thousand-fold in toxicity
with a drop of 1.5 pH units. The availability of many nutrient
195
-------
substances varies with the alkalinity and acidity. Ammonia is
more lethal with a higher pH.
The lacrimal fluid of the human eye has a pH of approximately 7.0
and a deviation of 0.1 pH unit from the norm may result in eye
irritation for the swimmer. Appreciable irritation will cause
severe pain.
Temperature
Temperature is one of the most important and influential water
quality characteristics. Temperature determines those species
that may be present; it activates the hatching of young,
regulates their activity, and stimulates or suppresses their
growth and development; it attracts, and may kill when the water
becomes too hot or becomes chilled too suddenly. Colder water
generally suppresses development. Warmer water generally
accelerates activity and may be a primary cause of aquatic plant
nuisances when other environmental factors are suitable.
Temperature is a prime regulator of natural processes within the
water environment. It governs physiological functions in
organisms and, acting directly or indirectly in combination with
other water quality constituents, it affects aquatic life with
each change. These effects include chemical reaction rates,
enzymatic functions, molecular movements, and molecular exchanges
between membranes within and between the physiological systems
and the organs of an animal.
Chemical reaction rates vary with temperature and generally
increase as the temperature is increased. The solubility of
gases in water varies with temperature. Dissolved oxygen is
decreased by the decay or decomposition of dissolved organic
substances and the decay rate increases as the temperature of the
water increases reaching a maximum at about 30°C (86°F). The
temperature of stream water, even during summer, is below the
optimum for pollution-associated bacteria. Increasing the water
temperature increases the bacterial multiplication rate when the
environment is favorable and the food supply is abundant.
Reproduction cycles may be changed significantly by increased
temperature because this function takes place under restricted
temperature ranges. Spawning may not occur at all because
temperatures are too high. Thus, a fish population may exist in
a heated area only by continued immigration. Disregarding the
decreased reproductive potential, water temperatures need not
reach lethal levels to decimate a species. Temperatures that
favor competitors, predators, parasites, and disease can destroy
a species at levels far below those that are lethal.
Fish food organisms are altered severely when temperatures
approach or exceed 90°F. Predominant algal species change,
primary production is decreased, and bottom associated organisms
may be depleted or altered drastically in numbers and
196
-------
distribution. Increased water temperatures may cause aquatic
plant nuisances when other environmental factors are favorable.
Synergistic actions of pollutants are more severe at higher water
temperatures. Given amounts of domestic sewage, refinery wastes,
oils, tars, insecticides, detergents, and fertilizers more
rapidly deplete oxygen in water at higher temperatures, and the
respective toxicities are likewise increased.
When water temperatures increase, the predominant algal species
may change from diatoms to green algae, and finally at high
temperatures to blue-green algae, because of species temperature
preferentials. Blue-green algae can cause serious odor problems.
The number and distribution of benthic organisms decreases as
water temperatures increase above 90°F, which is close to the
tolerance limit for the population. This could seriously affect
certain fish that depend on benthic organisms as a food source.
The cost of fish being attracted to heated water in winter months
may be considerable, due to fish mortalities that may result when
the fish return to the cooler water.
Rising temperatures stimulate the decomposition of sludge,
formation of. sludge gas, multiplication of saprophytic bacteria
and fungi (particularly in the presence of organic wastes), and
the consumption of oxygen by putrefactive processes, thus
affecting the esthetic value of a water course.
In general, marine water temperatures do not change as rapidly or
range as widely as those of freshwaters. Marine and estuarine
fishes, therefore, are less tolerant of temperature variation.
Although this limited tolerance is greater in estuarine than in
open water marine species, temperature changes are more important
to those fishes in estuaries and bays than to those in open
marine areas, because of the nursery and replenishment functions
of the estuary that can be adversely affected by extreme
temperature changes.
Dissolved Solids
In natural waters the dissolved solids consist mainly of
carbonates, chlorides, sulfates, phosphates, and possibly
nitrates of calcium, magnesium, sodium, and potassium, with
traces of iron, manganese and other substances.
Many communities in the United States and in other countries use
water supplies containing 2000 to UOOO mg/1 of dissolved salts,
when no better water is available. Such waters are not
palatable, may not quench thirst, and may have a laxative action
on new users. Waters containing more than UOOO mg/1 of total
salts are generally considered unfit for human use, although in
hot climates such higher salt concentrations can be tolerated
whereas they could not be in temperate climates. Waters
containing 5000 mg/1 or more are reported to be bitter and act as
bladder and intestinal irritants. It is generally agreed that
197
-------
the salt concentration of good, palatable water should not exceed
500 rag/1.
Limiting concentrations of dissolved solids for fresh-water fish
may range from 5,000 to 10,000 mg/1, according to species and
prior acclimatization. Some fish are adapted to living in more
saline waters, and a few species of fresh-water forms have been
found in natural waters with a salt concentration of 15,000 to
20,000 mg/1. Fish can slowly become acclimatized to higher
salinities, but fish in waters of low salinity cannot survive
sudden exposure to high salinities, such as those resulting from
discharges of oil-well brines. Dissolved solids may influence
the toxicity of heavy metals and organic compounds to fish and
other aquatic life, primarily because of the antagonistic effect
of hardness on metals.
Waters with total dissolved solids over 500 mg/1 have decreasing
utility as irrigation water. At 5,000 mg/1 water has little or
no value for irrigation.
Dissolved solids in industrial waters can cause foaming in
boilers and cause interference with cleaness, color, or taste of
many finished products. High contents of dissolved solids also
tend to accelerate corrosion.
Specific conductance is a measure of the capacity of water to
convey an electric current. This property is related to the
total concentration of ionized substances in water and water
temperature. This property is frequently used as a substitute
method of quickly estimating the dissolved solids concentration.
Total Suspended Solids
Suspended solids include both organic and inorganic materials.
The inorganic components include sand, silt, and clay. The
organic fraction includes such materials as grease, oil, tar,
animal and vegetable fats, various fibers, sawdust, hair, and
various materials from sewers. These solids may settle out
rapidly and bottom deposits are often a mixture of both organic
and inorganic solids. They adversely affect fisheries by
covering the bottom of the stream or lake with a blanket of
material that destroys the fish-food bottom fauna or the spawning
ground of fish. Deposits containing organic materials may
deplete bottom oxygen supplies and produce hydrogen sulfide,
carbon dioxide, methane; and other noxious gases.
In raw water sources for domestic use, state and regional
agencies generally specify that suspended solids in streams shall
not be present in sufficient concentration to be objectionable or
to interfere with normal treatment processes. Suspended solids
in water may interfere with many industrial processes, and cause
foaming in boilers, or encrustations on equipment exposed to
water, especially as the temperature rises. Suspended solids are
undesirable in water for textile industries; paper and pulp;
beverages; dairy products; laundries; dyeing; photography;
198
-------
cooling systems, and power plants. Suspended particles also
serve as a transport mechanism for pesticides and other
substances which are readily sorbed into or onto clay particles.
Solids may be suspended in water for a time, and then settle to
the bed of the stream or lake. These settleable solids
discharged with man's wastes may be inert, slowly biodegradable
materials, or rapidly decomposable substances. While in
suspension, they increase the turbidity of the water, reduce
light penetration and impair the photosynthetic activity of
aquatic plants.
Solids in suspension are aesthetically displeasing. When they
settle to form sludge deposits on the stream or lake bed, they
are often much more damaging to the life in water, and they
retain the capacity to displease the senses. Solids, when
transformed to sludge deposits, may do a variety of damaging
things, including blanketing the stream or lake bed and thereby
destroying the living spaces for those benthic organisms that
would otherwise occupy the habitat. When of an organic and
therefore decomposable nature, solids use a portion or all of the
dissolved oxygen available in the area. Organic materials also
serve as a seemingly inexhaustible food source for sludgeworms
and associated organisms.
Turbidity is principally a measure of the light absorbing
properties of suspended solids. It is frequently used as a
substitute method of quickly estimating the total suspended
solids when the concentration is relatively low.
Phosphorus
During the past 30 years, a formidable case has developed for the
belief that increasing standing crops of aquatic plant growths,
which often interfere with water uses and are nuisances to man,
frequently are caused 'by increasing supplies of phosphorus. Such
phenomena are associated with a condition of accelerated
eutrophication or aging of waters. It is generally recognized
that phosphorus is not the sole cause of eutrophication, but
there is evidence to substantiate that it is frequently the key
element in all of the elements required by fresh water plants and
is .generally present in the least amount relative to need.
Therefore, an increase in phosphorus allows use of other, already
present, nutrients for plant growths. Phosphorus is usually
described, for this reasons, as a "limiting factor."
when a plant population is stimulated in production and attains a
nuisance status, a large number of associated liabilities are
immediately apparent. Dense populations of pond weeds make
swimming dangerous. Boating and water skiing and sometimes
fishing may be eliminated because of the mass of vegetation that
serves as an physical impediment to such activities. Plant
populations have been associated with stunted fish populations
and with poor fishing. Plant nuisances emit vile stenches,
impart tastes and odors to water supplies, reduce the efficiency
199
-------
of industrial and municipal water treatment, impair aesthetic
beauty, reduce or restrict resort trade, lower waterfront
property values, cause skin rashes to man during water contact,
and serve as a desired substrate and breeding ground for flies.
Phosphorus in the elemental form is particularly toxic, and
subject to bioaccumulation in much the same way as mercury.
Colloidal elemental phosphorus will poison marine fish (causing
skin tissue breakdown and discoloration). Also, phosphorus is
capable of being concentrated and will accumulate in organs and
soft tissues. Experiments have shown that marine fish will
concentrate phosphorus from water containing as little as 1 ug/1.
Ammonia
Ammonia is a common product of the decomposition of organic
matter. Dead and decaying animals and plants along with human
and animal body wastes account for much of the ammonia entering
the aquatic ecosystem. Ammonia exists in its non-ionized form
only at higher pH levels and is the most toxic in this state.
The lower the pH, the more ionized ammonia is formed and its
toxicity decreases. Ammonia, in the presence of dissolved
oxygen, is converted to nitrate (NO3) by nitrifying bacteria.
Nitrite (NO2), which is an intermediate product between ammonia
and nitrate, sometimes occurs in quantity when depressed oxygen
conditions permit. Ammonia can exist in several other chemical
combinations including ammonium chloride and other salts.
Nitrates are considered to be among the poisonous ingredients of
mineralized waters, with potassium nitrate being more poisonous
than sodium nitrate. Excess nitrates cause irritation of the
mucous linings of the gastrointestinal tract and the bladder; the
symptoms are diarrhea and diuresis, and drinking one liter of
water containing 500 mg/1 of nitrate can cause such symptoms.
Infant methemoglobinemia, a disease characterized by certain
specific blood changes and cyanosis, may be caused by high
nitrate concentrations in the water used for preparing feeding
formulae. While it is still impossible to state precise
concentration limits, it has been widely recommended that water
containing more than 10 mg/1 of nitrate nitrogen (NO3-N) should
not be used for infants. Nitrates are also harmful in
fermentation processes and can cause disagreeable tastes in beer.
In most natural water the pH range is such that ammonium ions
(NHJH-) predominate. In alkaline waters, however, high
concentrations of un-ionized ammonia in undissociated ammonium
hydroxide increase the toxicity of ammonia solutions. In streams
polluted with sewage, up to one half of the nitrogen in the
sewage may be in the form of free ammonia, and sewage may carry
up to 35 mg/1 of total nitrogen. It has been shown that at a
level of 1.0 mg/1 un-ionized ammonia, the ability of hemoglobin
to combine with oxygen is impaired and fish may suffocate.
Evidence indicates that ammonia exerts a considerable toxic
effect on all aquatic life within a range of less than 1.0 mg/1
200
-------
to 25 mg/1, depending on the pH and dissolved oxygen level
present.
Ammonia can add to the problem of eutrophication by supplying
nitrogen through its breakdown products. Some lakes in warmer
climates, and others that are aging quickly are sometimes limited
by the nitrogen available. Any increase will speed up the plant
growth and decay process.
Copper
Copper salts occur in natural surface waters only in trace
amounts, up to about 0.05 mg/1, so that their presence generally
is the result of pollution. This is attributable to the
corrosive action of the water on copper and brass tubing, to
industrial effluents, and frequently to the use of copper
compounds for the control of undesirable plankton organisms.
Copper is not considered to be a cumulative systemic poison for
humans, but it can cause symptoms of gastroenteritis, with nausea
and intestinal irritations, at relatively low dosages. The
limiting factor in domestic water supplies is taste. Threshold
concentrations for taste have been generally reported in the
range of 1.0-2.0 mg/1 of copper, while as much as 5-7.5 mg/1
makes the water completely unpalatable.
The toxicity of copper to aquatic organisms varies significantly,
not only with the species, but also with the physical and
chemical characteristics of the water, including temperature,
hardness, turbidity, and carbon dioxide content. In hard water,
the toxicity of copper salts is reduced by the precipitation of
copper carbonate or other insoluble compounds. The sulfates of
copper and zinc, and of copper and cadmium are synergistic in
their toxic effect on fish.
Copper concentrations less than 1 mg/1 have been reported to be
toxic, particularly in soft water, to many kinds of fish,
crustaceans, mollusks, insects, phytoplankton and zooplankton.
Concentrations of copper, for example, are detrimental to some
oysters above .1 ppm. Oysters cultured in sea water containing
0.13-0.5 ppm of copper deposited the metal in their bodies and
became unfit as a food substance.
Chromium
Chromium, in its various valence states, is hazardous to man. It
can produce lung tumors when inhaled and induces skin
sensitizations. Large doses of chromates have corrosive effects
on the intestinal tract and can cause inflammation of the
kidneys. Levels of chromate ions that have no effect on man
appear to be so low as to prohibit determination to date.
The toxicity of chromium salts toward aquatic life varies widely
with the species, temperature, pH, valence of the chromium, and
synergistic or antagonistic effects, especially that of hardness.
201
-------
Fish are relatively tolerant of chromium salts, but fish food
organisms and other lower forms of aquatic life are extremely
sensitive. Chromium also inhibits the growth of algae.
In some agricultural crops, chromium can cause reduced growth or
death of the crop. Adverse effects of low concentrations of
chromium on corn, tobacco and sugar beets have been documented.
Arsenic
Arsenic is found to a small extent in nature in the elemental
form. It occurs mostly in the form of arsenites of metals or as
pyrites.
Arsenic is normally present in sea water at concentrations of 2
to 3 ug/1 and tends to be accumulated by oysters and other
shellfish. Concentrations of 100 mg/kg have been reported in
certain shellfish. Arsenic is a cumulative poison with long-term
chronic effects on both aquatic organisms and on mammalian
species and a succession of small doses may add up to a final
lethal dose. It is moderately toxic to plants and highly toxic
to animals especially as AsH3.
Arsenic trioxide, which also is exceedingly toxic, was studied in
concentrations of 1.96 to ^0 mg/1 and found to be harmful in that
range to fish and other aquatic life. Work by the Washington
Department of Fisheries on pink salmon has shown that at a level
of 5.3 mg/1 of As2O3 for 8 days was extremely harmful to this
species; on mussels, a level of 16 mg/1 was lethal in 3 to 16
days.
Severe human poisoning can result from 100 mg concentrations, and
130 mg has proved fatal. Arsenic can accumulate in the body
faster than it is excreted and can build to toxic levels, from
small amounts taken periodically through lung and intestinal
walls from the air, water and food.
Arsenic is a normal constituent of most soils, with
concentrations ranging up to 500 mg/kg. Although very low
concentrations of arsenates may actually stimulate plant growth,
the presence of excessive soluble arsenic in irrigation waters
will reduce the yield of crops, the main effect appearing to be
the destruction of chlorophyll in the foliage. Plants grown in
water containing one mg/1 of arsenic trioxides showed a
blackening of the vascular bundles in the leaves. Beans and
cucumbers are very sensitive, while turnips, cereals, and grasses
are relatively resistant. Old orchard soils in Washington that
contained H to 12 mg/kg of arsenic trioxide in the top soil were
found to have become unproductive.
Zinc
Occurring abundantly in rocks and ores, zinc is readily refined
into a stable pure metal and is used extensively for galvanizing,
in alloys, for electrical purposes, in printing plates, for dye-
202
-------
manufacture and for dyeing processes, and for many other
industrial purposes. Zinc salts are used in paint pigments,
cosmetics, Pharmaceuticals, dyes, insecticides, and other
products too numerous to list herein. Many of these salts (e.g.,
zinc chloride and zinc sulfate) are highly soluble in water;
hence it is to be expected that zinc might occur in many
industrial wastes. On the other hand, some zinc salts (zinc
carbonate, zinc oxide, zinc sulfide) are insoluble in water and
consequently it is to be expected that some zinc will precipitate
and be removed readily in most natural waters.
In zinc-mining areas, zinc has been found in waters in
concentrations as high as 50 mg/1 and in effluents from metal-
plating works and small-arms ammunition plants it may occur in
significant concentrations. In most surface and ground waters,
it is present only in trace amounts. There is some evidence that
zinc ions are adsorbed strongly and permanently on silt,
resulting in inactivation of the zinc.
Concentrations of zinc in excess of 5 mg/1 in raw water used for
drinking water supplies cause an undesirable taste which persists
through conventional treatment. Zinc can have an adverse effect
on man and animals at high concentrations.
In soft water, concentrations of zinc ranging from 0.1 to 1.0
mg/1 have been reported to be lethal to fish. Zinc is thought to
exert its toxic action by forming insoluble compounds with the
mucous that covers the gills, by damage to the gill epithelium,
or possibly by acting as an internal poison. The sensitivity of
fish to zinc varies with species, age and condition, as well as
with the physical and chemical characteristics of the water.
Some acclimatization to the presence of zinc is possible. It has
also been observed that the effects of zinc poisoning may not
become apparent immediately, so that fish removed from zinc-
contaminated to zinc-free water (after 4-6 hours of exposure to
zinc) may die 48 hours later. The presence of copper in water
may increase the toxicity of zinc to aquatic organisms, but the
presence of
toxicity.
calcium or hardness may decrease the relative
Observed values for the distribution of zinc in ocean waters vary
widely. The major concern with zinc compounds in marine waters
is not one of acute toxicity, but rather of the long-term sub-
lethal effects of the metallic compounds and complexes. From an
acute toxicity point of view, invertebrate marine animals seem to
be the most sensitive organisms tested. The growth of the sea
urchin, for example, has been retarded by as little as 30 ug/1 of
zinc.
Zinc sulfate has also been found to be lethal to many plants, and
it could impair agricultural uses.
203
-------
Fluorides
As the most reactive non-metal, fluorine is never found free in
nature but as a constituent of fluorite or fluorspar, calcium
fluoride, in sedimentary rocks and also of cryolite, sodium
aluminum fluoride, in igneous rocks. Owing to their origin only
in certain types of rocks and only in a few regions, fluorides in
high concentrations are not a common constituent of natural
surface waters, but they may occur in detrimental concentrations
in ground waters.
Fluorides are used as insecticides, for disinfecting brewery
apparatus, as a flux in the manufacture of steel, for preserving
wood and mucilages, for the manufacture of glass and enamels, in
chemical industries, for water treatment, and for other uses.
Fluorides in sufficient quantity are toxic to humans, with
of 250 to 450 mg giving severe symptoms or causing death.
doses
There are numerous articles describing the effects of fluoride-
bearing waters on dental enamel of children; these studies lead
to the generalization that water containing less than 0.9 to 1.0
mg/1 of fluoride will seldom cause mottled enamel in children,
and for adults, concentrations less than 3 or 4 mg/1 are not
likely to cause endemic cumulative fluorosis and skeletal
effects. Abundant literature is also available describing the
advantages of maintaining 0.8 to 1.5 mg/1 of fluoride ion in
drinking water to aid in the reduction of dental decay,
especially among children.
Chronic fluoride poisoning of livestock has been observed in
areas where water contained 10 to 15 mg/1 fluoride.
Concentrations of 30 - 50 mg/1 of fluoride in the total ration of
dairy co-vs is considered the upper safe limit. Fluoride from
waters apparently does not accumulate in soft tissue to a
significant degree and it is transferred to a very small extent
into the milk and to a somewhat greater degree into eggs. Data
for fresh water indicate that fluorides are toxic to fish at
concentrations higher than 1.5 mg/1.
20k
-------
6OO-
500 H
-s.
O
E
.400-1
O
o
DO
300 H
200
IOO 99.75
99.50
99.25 9900
SAMPLE DILUTION (% )
FIGURE 43. BOD -3 VARIATION WITH DILUTION
205
-------
20-1
1*0
O
z
UJ
cc
I-
W
UJ
H
O)
|
-------
TABLE 51
RETARDATION OF BOD TEST TIMBER PRODUCTS EFFLUENTS (LEACHATES)
Concentration For TLm96
Study
Identification No
1135
2176
2347
Materials
logs/w/bark
logs/wo/bark
bark-hardwood
bark-softwood
wood chips @40°C
wood chips @32°C
F1sh at Test -
chlnook,
chlnook,
chlnook,
chlnook,
guppies
guppies
salmon
salmon
salmon, flngerllngs
salmon, flngerllngs
BOD
16.8
28.8
69.3
63.00
92.4
108.8
COD
54.4
75.2
537.6
483.0
336.0
400.0
NOTE: No dissolved oxygen data presented for the studies.
-------
-------
SECTION VII
CONTROL AND TREATMENT TECHNOLOGY
This section identifies, documents, and verifies the full range
of control and treatment technology which exists or is applicable
to each operation identified in Section IV. In addition, it
presents the control and treatment alternatives applicable to the
model plants developed in Section V.
IMPOUNDMENTS AND ESTUARINE STORAGE AND TRANSPORTATION
The control of pollutants generated by log storage and
transportation, other than log storage in ponds, can be
accomplished primarily by operational modifications. Water
pollution by log storage and transportation could be virtually
eliminated by a transition of the industry to total land handling
of logs; however, as indicated in Section VIII, the non water
related environmental impact of such action would be severe.
The most important of the operational controls that have been
investigated is the employment of easy let-down devices for
placing logs into the water. The easy let-down devices and the
practice of bundling logs either in the water or prior to
placement in the water has been effective in reducing the eyesore
of floating bark and the pollution problems associated with bark
deposits on the bottom of waterways. In some instances, the
number of logs in the water at any one time has been reduced
considerably. This is practical for those locations where the
impoundment is used only to feed the mill.
WET STORAGE
Presented below is a discussion of treatment and control
technology applicable to the wet storage subcategory. The
discussion is further broken down into mill ponds, log ponds, and
wet decking operations. This breakdown of ponds into mill ponds
and log ponds is useful in demonstrating the differences in
quality and quantity of waste waters generated and the applicable
treatment and control technology that are dependent on the type
of activity occurring at the ponds, the location of the activity
with regard to the location of the discharge and the throughput
rates of the wood material and water.
MILL PONDS
The mill pond as it currently exists has evolved from the logging
practices in the past. Waterways were used originally to
transport logs from the forests to processing areas. As a
result, most mill machinery is still water oriented, but the size
of the water associated operations have diminished to the present
mill pond. Most plants still dump logs into the mill pond in the
same fashion as when loading logs from trucks and trains first
became the practice. Most managers of mill pond operations allow
209
-------
a considerable amount of activity near the effluent structure and
almost all still place the logs in the pond without prior bark
removal. Some mills remove the ends of the logs while the log is
still in the water, thus allowing sawdust to be contributed
directly to the pond,
Existing Operational Control Measures
Several operational load measures may be taken to reduce
pollution load of mill pond effluents. Logs can be barked prior
to being placed in the pond. This practice substantially
diminishes the amount of floating bark in the pond. Another
control measure common to most mill pond operations is the use of
baffles near the discharge effluent of the pond. The baffles are
placed so as to protrude through the water surface. This
prevents floating material from passing over the weir and out of
the pond. In some cases, the baffles are placed far enough from
the effluent weir that the bottom muds stirred up by the activity
on the pond can settle and not be passed over the effluent weir.
Another practice is the use of a submerged discharge, that is,
the water to be discharged is drawn from below the surface of the
pond. This prevents the carryover of floating material. Another
operational control measure observed was the use of surface spray
nozzles to contain the floating debris in a mill pond near the
sawing operation. Surface sprays are particularly effective for
control of sawdust generated by pond sawing operations. The
screening of the water that entered the area near the mill
operation to remove sawdust and bark from the water was also
observed to be used as a control measure.
Potential Operational Control Measures
As previously mentioned, the sawing of logs while still in the
water was observed in several locations. The elimination of this
practice by sawing all logs on land would prevent the sawdust and
bark generated from entering the pond water system. The removal
of bark before placement in the water would reduce floating and
settled bark as well as the leachates from the bark. When the
logs are placed in the water without prior bark removal, smaller
quantities of bark would be loosened from the logs if easy let-
down devices were utilized. The quantity of water emanating from
a mill pond can be markedly reduced if all storm runoff is
diverted around the pond. This can be accomplished with an open
diversion ditch in most cases, but in some cases, a larger closed
conduit may be required. The amount of bottom materials stirred
up during the log moving operations may be diminished markedly by
using boats that have smaller engines than those currently in
use. In this case, the decreased productivity of the operator
would have to be a factor of consideration.
210
-------
Potential Operational Control Measures
There are several potential control measures for reducing the
effluent from ponds or increasing its quality. The primary
source of influents to ponds may be drainage. However, since
most log ponds also serve as mill ponds, they are normally kept
full and overflow as a result of precipitation. One method of
minimizing the amount of material washed from the log pond would
be to enlarge the pond and allow the water levels to fluctuate.
In that fashion the amount of water leaving the pond because of
precipitation would only be that in excess of the amount
evaporated. The pond would be at minimum depth at the end of the
dry season and would overflow late in the rainy season. The
water level in the model pond would fluctuate from 1 to 2 m (two
to six ft) or more depending on the water balance for the area.
This method would require the diversion of all drainage away from
the pond, an action that in itself is a control measure.
Another operational control measure that would reduce the amount
and possibly the concentration of pollutants in the pond effluent
would be to prohibit all discharge or water streams to the pond.
This would be the most effective of reducing discharge from the
log pond, but it may not be the most practical approach when the
entire mill complex is considered. The log pond can serve as an
oxidation pond and it may have some assimilative capacity beyond
that required for pollutants leached from the logs. Cooling
water flows may need special consideration, yet the log pond can
also serve as a cooling pond for heated water. Also, the
addition of warm water during winter conditions can be beneficial
in preventing freezing of wood and water.
The effluent from a mill or log pond may be screened for large
solids removal. This will accomplish the removal of a portion of
the suspended and floating solids, and primarily that, portion
that is aesthetically objectionable. Settling ponds may also be
used for clarification of the pond effluent. An example of this
technology for removal of settleable solids from both surface
runoff and process water is reported in Forest, Industries,
November 1972. The ponds discussed in this reference had asphalt
bottoms and sloped driveways leading into them. The ponds are
periodically drained and the accumulated sediment trucked away.
TREATMENT AND CONTROL
The treatment and control technology currently available and that
potentially available are essentially the same for log ponds and
mill ponds. Unlike the mill pond, the amount of suspended solids
in a typical log pond effluent is sufficiently low that the use
of primary sedimentation is not necessary. If the water level in
the log pond can be allowed to fluctuate, then the log pond
itself can act as the basin. In application of the evaporation
pond designed for the mill pond effluent to the log pond
effluent, only spray evaporation must be added. This design
concept was added to the treatment plant schemes for mill ponds.
211
-------
For application of all of the designs for mill ponds to log
ponds, the flow rate from the equalization basin to the treatment
works was considered to be 3800 cu m per day (1.0 mgd) . A
laboratory study of the treatability of log pond waters by
physical-chemical means by Blauton showed that sand filtration
was relatively ineffective. The study showed that BOD removals
of 7 to 49 percent and COD removals of 52 to 67 percent were
possible using alum at an optimum coagulation pH of 5.0. The
study further indicated that activated carbon could be used to
reduce COD concentrations to less than 50 milligrams per liter
even in the pond effluent by removing 272 to 485 milligrams COD
per gram of carbon. The treatability of log pond waters using an
activated sludge system with a detention time of from one to five
days was studied by Hoffbahr. It was found that BOD, COD, and
suspended solids removals of greater than 80 percent, 50 percent,
and 60 percent respectively, could be obtained. The BOD, COD,
and suspended solids of the influent waters were 52, 440, and 160
milligrams per liter, respectively.
The removal of lignins is important in the treatment of wood
derived pollutants as shown by Wilson and Wong who studied the
removal of lignins from solution using foam separation processes.
It was found that foam fractionation is ineffective in removing
lignins but ion flotation under the proper conditions yielded up
to 91 percent removal. However, the total dissolved solids
required for the separation to be possible was at such a high
level as to render the process impractical.
The treatment of the wastes from mill ponds can be accomplished
using both chemical-physical and biological processes. A
thorough discussion of the various processes available can be
found in waste water treatment texts. More specifically. Bailey
investigated the applicability of aerated lagoons for treating
pulp and paper mill wastes and found BOD reductions of up to 70
percent. In a study by Timpany, et al. 60 to 80 percent BOD
removal efficiencies were illustrated for aerated lagoons with
detention times of five days treating pulp and paper mill
effluents. Other studies have substantiated the applicability of
the technology for treating waste waters resulting from timber
products processing waste stream.
Treatment Alternatives for Model Mill Pond
Six alternative treatment schemes were chosen for treatment of
the effluent from the model mill pond. These systems are
illustrated in Figure 45. A summary of the removal efficiencies
of the alternatives is presented in Table 52. The treatment
alternatives selected for the model mill pond are:
Alternative A:
No treatment
212
-------
ALTERNATIVE - A : •«> TMATMENT
ALTERNATIVE - B :
EQUALIZATION BASIN
PRIMARY SEDIMENTATION
ALTERNATIVE-C :
1 »
*
EQALIZATION BASIN
OXIDATION POND No. 1
OXIDATION
POND Ne.2
ALTERNATIVE - 0 :
| .
1 "
PRIMARY SEDIMENTATION
CHEMICAL
FLOCCULATION
SECONDARY
SEDIMENTATION
ALTERNATIVE - E !
MILL A fc
POND J '
<^-*
-------
TABLE 52
EFFICIENCIES AND CONCENTRATION FOR THE VARIOUS TREATMENT
ALTERNATIVES FOR MILL PONDS
_COD_ ______ Suspended So1ids_
Percent COD
Reduction in
Alternatives the Unit
A
Bl, Cl, Dl, El
C2
D2, E2
E3
E4
Fl
0
20
60
60
20
75
100
Percent Suspended Influent Effluent Influent Effluent
Solids Reduction Concentration Concentration Concentration Concentration
in the Unit (mg/1) (mg/1) (mg/1) (mg/1)
0
50
20
90
90
0
100
68
68
54
54
22
17.6
68
68
54
22
22
17.6
4.4
0
50
50
25
25
2.5
0.25
50
50
25
20
2.5
0.25
0.25
0
-------
Alternative B:
Equalization basin and primary sedimentation
Alternative C:
C1 Equalization basin - oxidation pond No. 1
C2 Oxidation pond No. 2
Alternative D:
D1 Equalization basin - primary sedimentation
D2 Chemical coagulation - flocculation, secondary sedimen-
tation
Alternative E:
E1 Equalization basin - primary sedimentation
E2 chemical coagulation - flocculation, secondary sedimen-
tation
E3 Filtration
E4 Activated carbon
Alternative F:
Evaporation pond
Alternative A - In alternative A, there is no treatment and,
therefore, no reduction in the quantity of pollutants discharging
from the mill pond. For those mill ponds that have high water
volume throughput rate, diversion of that water around the mill
pond will reduce the amount of pollutants discharged by the pond.
Alternative B - In alternative Br an equilization basin is
coupled with a primary sedimentation unit. The mill pond that
has had all extraneous water diverted from it will discharge only
when precipitation occurs. The designs of mill ponds, and the
predicted effluents are, therefore, a function of the size of the
pond, the quantity of precipitation on the pond, and the rate of
evaporation from the pond. The amount of precipitation and the
evaporation rate were chosen based on geographical location.
Because most mill ponds are located in the Northwest, and because
the Seattle, WAf area has one of the highest rainfall rates and
one of the lowest evaporation rates in the Northwest, the
precipitation-evaporation data in the Seattle, WA, area were
used. A one hectare (2.5 acre) pond was assumed. In this area,
about 75 percent of the total annual precipitation occurs in the
winter months. It was, therefore, assumed that treatment of the
effluent would be necessary only during the winter months, and
that the evaporation rate would exceed the precipitation rate and
no discharge flow would occur during the summer months. An
equilization basin must be provided to accomodate the high flows
during rainy weather with flows during periods of no
precipitation. A treatment plant could, therefore, operate with
a nearly constant flow rate throughout the winter months. From
215
-------
the rainfall data, it was possible to calculate that the
treatment plant would have to operate at a rate of 3 Ips (50 gpm)
and the equalization basin would have to have a volume of about
1*000 cu m (1 million gal) .
The effluent characteristics of the typical mill pond indicate
that a sedimentation system might be a beneficial treatment
process. In addition, it would be less costly to allow the
equalization basin to also serve as a sedimentation chamber.
This was considered and the design of the equalization basin
modified accordingly.
The design for Alternative B then would be as shown in Figure 46.
Design assumptions include the following:
1. The basin will be cleaned annually (in the dry season) .
2. Cleaning to be performed with a drag line or a front end
loader.
3. Water level will fluctuate between 0.9 m (3 ft) and 2.5
(8 ft) depth.
4. Sludge production is estimated at 200 cu m
Disposal would be by land spreading.
5. Basin walls = packed earth
per year
6.
7.
Basin size at inside top of berm = 59.
m
Effluent weir variable (by hand) from 0.9 m (3 ft) depth
to 2.5 m (8 ft) depth.
8. Provide wet well for pump.
The predicted treatment efficiency for Alternative B1 is 20
percent COD removal and 50 percent suspended solids removal.
These predictions are based on the characteristics of the
effluent water, the laboratory studies reported previously, and
the expected performance of this type of installation.
Alternative C - This alternative involves two steps. Alternative
C1 consists of an equalization basin functioning as an anaerobic-
aerobic oxidation pond with a variable influent and a constant
effluent. The design of C1 is the same as the design of Alterna-
tive B.
Alternative C2 consists of an oxidation pond which receives the
effluent from the equalization basin. The construction of the
second oxidation pond is the same as the first with the exception
that the berm is two m (seven ft) high and the basin size at the
raised top of the berm is 53 m (175 ft) instead of the 59 m (195
ft) of the first basin* The effluent weir is arranged at an
elevation that allows a maximum of one meter (five ft) of water
to be maintained in the pond at all times.
216
-------
EFFLUENT
FROM MILL
POND
PUMP
EQUALIZATION
SEDIMENTATION
BASIN
59.4m
FIGURE 46 ALTERNATIVE B FOR MILL PONDS
217
-------
The predicted treatment efficiency of Alternative C2 is 60
percent COD removal and 20 percent suspended solids removal. The
higher COD removal results from a more uniform flow and a uniform
detention time. The lower suspended solids reduction is based on
the fact that most of the settleable solids will be removed in
the first basin.
Alternative D - Alternative D consists of the addition of
chemical treatment to the sedimentation equalization basin
described for Alternative B and C1. Alternative D1 consists of
the equalization basin. Alternative D2 consists of chemical
coagulation, flocculation, and sedimentation.
Consideration was given in this alternative to chemical addition
and mixing. A baffled flocculator was provided as well as a
sedimentation tank. Sludge disposal was provided by using a
settling pond with supernatant returned to the equalization
basin. The sludge is assumed to be landfilled. The sludge pond
is designed to accomodate both the sludge from chemical
coagulation-flocculation-secondary sedimentation and filter
backwash water.
The predicted COD and suspended solids removals for Alternative
D2 are 60 percent and 90 percent, respectively. These removal
efficiencies are normally expected for these units.
Alternative D2 is schematically shown in Figure 47. The
following design criteria were employed:
1. Mixing and Chemical Addition
a. Design flow = 30 Ips.
b. Mixing chamber =0.5mx0.5mx 0.5 m, made of
steel or reinforced concrete.
c. Mixer = 1.0 horsepower motor with appropriate
blade.
d. Flocculant feed pump = 10 to 40 1 per hour.
e. Coagulant feeding equipment = dry feeder for up to
90 kilograms per day of A12 (SO4J3.
f. Flocculant mixing equipment - 1 - 570 liter tank
and a one and one-half horsepower mixer.
2. Flocculator
a. The flocculator is a baffled channel.
b. Construction = reinforced concrete.
c. Around the end baffles in a folded channel.
218
-------
EQUALIZATION
BASIN
EFFLUENT
MIXING
CHEMICALS
9m I 0.9m O.9m j 0.9m
4.5m
SLUDGE
TREATED
EFFLUENT
SLUDGE FROM
FILTER BACKWASH
0.9m
SUPERNATANT
TO EQUALIZATION
BASIN '
FIGURE 47 ALTERNATIVE D2 FOR MILL PONDS
219
-------
d. Channel depth = 1,2 m.
3. Sedimentation Chamber
a. Mechanically cleaned.
b. Continuous sludge withdrawal.
c. Surface skimming not necessary.
d. Provide influent and effluent baffles.
e. Longitudinal flow, rectangular tank.
f. Depth = 3.7 m width = 2.U m, and length = 4.3 m.
g. Reinforced concrete construction.
5. Sludge Disposal
a. Sludge from chemical coagulation-sedimentation and
filter backwash water.
b. Estimated settled volume = 490 cu m per year.
c. Settling pond size 30.5 m x 30.5 m.
d. Overflow weir 32m depth.
e. Annual cleaning.
f. Sludge disposal to sanitary landfill.
g. Pump to return supernatant to equalization basin.
Alternative E - In Alternative E, the unit operations of
filtration and physical adsorption by activated carbon are added
to Alternative D.
Alternative E is considered to consist of three steps:
Alternative El, an equalization basin as designed for
Alternatives B, C1, and D1;
Alternative E2, chemical treatment as designed for Alternative
C2;
Alternative E3, single media pressure sand filtration; and
Alternative E4, activated carbon treatment.
Following the removal of a large portion of the suspended solids
in the waste water by chemical treatment, the treated waste water
still contains some solids from floe carryover. This floe will
tend to plug the activated carbon system and reduce its
efficiency for absorption of organics. Most of the floe can be
removed by pressure filtration.
The activated carbon system is intended to remove soluble
organics by physical adsorption. The system is designed as an
220
-------
upflow suspended bed of granular activated carbon. The spent
activated carbon should be wasted or recharged off-site.
Recharging on-site, for such a small quantity, would be cost
prohibitive.
The predicted COD and suspended solids removals in the pressure
filtration unit are 20 percent and 90 percent, respectively. In
the activated carbon unit, the predicted COD removal efficiency
is 75 percent, leaving a COD in the final effluent of less than 5
gm/1.
A schematic of Alternative E is shown in Figure 48. The
following design criteria are involved:
1. Pressure Filtration
a. Pressure sand filter (single media).
b. Tank = 1.8 m diameter, 1.8 m height, with legs and
manhole.
c. Underdrain = graded gravel.
d. Media = 80 cm of silica sand, effective diam = 0.5
mm, uniformity coefficient =1.5.
e. Two parallel units.
f. Provide feed pump for 3 Ips S TDK = 15.2 m.
g. Provide backwash pump for 25 Ips 9 TDH = 7.6 m.
h. Backwash with dirty water from equalization basin,
provide for initial filtration to equalization
basin until effluent is clear.
i. Backwash water treatment provided elsewhere.
2. Activated Carbon
a. Upflow contactors.
b.
c.
d.
e.
Three units, two operated in parallel while third
is recharged.
Must recharge one unit every two days.
Provide underdrain system.
Pumping for filtration will also serve
activated carbon.
for
221
-------
OXIDATION
POND
^
CHEMICAL
TREATMENT
BACKWASH
PUMP
BACKWASH
ACTIVATED CARBON
PRESSURE FILTRATION
FIGURE 48 ALTERNATIVE E FOR MILL PONDS
222
-------
f.
g.
h.
i.
Columns = 0.9
removal tops.
m
diameter x U.0 m height with
Columns = steel tanks.
Provide for 102 kg of activated carbon per day.
Provide for recharge off site, or discard the spent
carbon. If discard is used, the spent carbon will
be incorporated in the sludge treatment system for
coagulation and for filter backwash.
j. Provide for equipment to empty and fill columns.
k. Equipment will be housed in filter building.
Alternative F - Alternative F consists of an evaporation pond for
the containment of the total discharge from the mill pond. The
design of the evaporation pond takes into account the
geographical variation of evaporation and precipitation rates.
It provides for spray evaporators to operate continuously for
five months of the year. The pond is designed to contain all
precipitation falling on itself as well as that falling on the
mill pond. The efficiency of the unit for removal of pollutants
is 100 percent.
A schematic of Alternative F is presented in Figure 49.
following design criteria are employed:
The
1.
2.
3.
Spray evaporation necessary (Seattle, Washington) .
Pond size = 3 ha.
Pond shape = canal 38 m wide and 850 m long.
U. Sixteen floating pumps d 75 hp each.
5. Pond depth = 3 m of water.
6. Place pond perpendicular to prevailing wind.
LOG PONDS
Log ponds differ from mill ponds in several ways including the
fact that they are constructed at a key location for the specific
purpose of storing logs. Most log ponds have processing mills on
their banks and in many cases the mill discharges its waste water
to the log pond. The discussion in this section will only be
concerned with log handling operations on the pond and not with
treatment and control measures relevant to extraneous streams
entering the log pond.
223
-------
45.7 m
X X X X X
XX*X,XXXXX
650 m
36m
FIGURE 49 ALTERNATIVE F FOR HILL PONDS
221*
-------
Existing Operational Control Measures
The only existing operational control measure observed in this
study is the bundling of logs prior to placement in the log pond.
This practice decreased the bark loss during the log dumping
operation and allowed more logs to be stored on the same pond.
Treatment and Control Technology
The treatment alternatives selected for the model log pond are
illustrated in Figure 50. Table 53 presents a summary of the
efficiencies of the alternatives. The selected alternatives are:
Alternative A:
No treatment
Alternative B:
B1 Equalization basin, oxidation pond No. 1
B2 Oxidation pond No. 2
Alternative C:
C1 Equalization basin
C2 Chemical coagulation - flocculation, sedimentation
Alternative D:
- flocculation, sedimentation
D1 Equalization basin
D2 Chemical coagulation
D3 Filtration
DU Activated carbon
Alternative E:
•Use. of the log pond as an evaporation pond.
Alternative A - In Alternative A, there is no treatment and no
reduction of the pollutant load. Some of the inplant measures
recommended previously should reduce the load from the log pond.
All extraneous flows should be diverted around the log pond and,
if possible, maximum water level fluctuation should be allowed.
Alternative B - In Alternative B an equalization-oxidation pond
is coupled with a second oxidation pond (Alternative B2). The
design of Alternative B1 for the pond was accomplished in the
same fashion as Alternative C for mill ponds. The required
storage in the equalization basin was found to be 53,000 cu m (Itt
million gal) and the treatment plant flow rate was in excess of
30 Ips (500 gpm):; therefore, a design flow of 3,800 cu m per day
{one million gal per day) was used.
225
-------
ALTERNATIVE-A:
NO TRCATMCMT
ALTERNATIVE -
EQUALIZATION BASIN
OXIDATION
POND N«.2
ALTERNATIVE-
EQUALIZATION
8ASIN
CHEMICAL COACULATK*
SEDIMENTATION
ALTERNATIVE-
EQUALIZATION
6ASIN
•4-
CHEMICAL
FLOCCULATION
ACTIVATED
CARBON
SEDIMENTATION
FILTRATION
ALTERNATIVE-
ATMOSPHERE
A 444
C
LOG
POND
EVAPORATION
POND
FIGURE 50 ALTERNATIVE TREATMENT SCHEMES FOR LOG PONDS
226
-------
TABLE 53
EFFICIENCIES AND CONCENTRATIONS FOR THE VARIOUS
TREATMENT ALTERNATIVES FOR LOG PONDS
COD
Suspended Solids
ro
ro
Alternatives
A
B1,C1,D1,E1
B2
C2, 02
D3
D4
El
Percent COD
Reduction in
the Unit
0
20
60
60
20
75
100
Percent Suspended Influent
Solids Reduction Concentration
in the Unit (mq/1)
0
20
50
60
90
0
100,
52
52
42
42
17
14
52
Effluent Influent
Concentration Concentration
(mq/1) (mg/1)
52
42
17
17
14
3.5
0
21
21
17
17
1.7
0.2
21
Effluent
Concentration
(mg/1 )
21
17
8.5
1.7
0.2
0.2
0
-------
The waste water from a log pond is sufficiently low in suspended
and settleable solids that a primary sedimentation chamber is not
considered necessary. For this reason, Alternative B is a
combination equalization basin and oxidation pond.
Just as in Alternative C for mill ponds, this design provides for
a second oxidation pond, in series. In this case, the size of
the second pond is the same as the first. The only difference is
that the flow through the second pond is controlled by gravity
rather than by a pump.
Alternative B1 provides a removal efficiency of 20 percent for
both COD and suspended solids. Alternative B2 provides removal
efficiencies of 60 percent and 50 percent for COD and suspended
solids, respectively.
Alternative B is illustrated in Figure 51.
for each pond are as follows:
The design criteria
1. Effluent from the basin to be
3,800 cu m per day.
pumped at the rate of
2, Water level will fluctuate between 0 and 1,5 m depth.
3. Provide wet well for pump.
ft. Basin size at inside top of berm = 213.** m
Alternative C - Alternative c consists of an equalization pond
(Alternative C1) followed by chemical treatment (Alternative C2).
The design and efficiencies of Alternative C1 are the same as for
Alternative B1. The design of Alternative C2 is similar to the
design of Alternative D2 for mill ponds. However, instead of the
"around the end" baffle system in the flocculator used for mill
ponds. Alternative C2 employs an "over and under" system. The
reason for this difference is that more reliability is provided
by the parallel sedimentation tanks of this design.
Alternative C1 provides a removal efficiency of 20 percent for
both COD and suspended solids. Alternative C2 provides removal
efficiencies of 60 percent and 90 percent for COD and suspended
solids, respectively.
Alternative C is illustrated in Figure 52. The following design
criteria are employed:
1. Mixing and chemical addition
a. Design flow = 4U Ips (694 gpm or 3,800 cu m per day
(1 mgd) .
b. Mixing chamber = 1.8 m x 1.8 x 2.4 m deep,
reinforced concrete.
c. Mixer = 5.0 horsepower motor with appropriate blade
228
-------
EFFLUENT
FROM LOG
POND
EQUALIZATION
OXIDATION POND
OXIDATION
POND
I.Zrrv
213.4m
<\
3
'CS
3
FIGURE 51 ALTERNATIVE B FOR LOG PONDS
229
-------
LOG POND
EFFLUENT
• EOALIZATION
-M OXIDATION
I POND
H
OXIDATION
POND
MIXING
.CHEMICALS
1.8m TYPICAL
M »•
•0,3m
1.2m
O.9m I I FLOCCULATOR
9.1m
TREATMENT
EFFLUENT
3.4m
SEDIMENTATION
SLUDGE
1.2m
67.1m
3 I •
SLUDGE POND
2.7m
FIGURE 52 ALTERNATIVE C FOR LOG PONDS
230
-------
2.
3.
5.
d. Flocculator feed pump = 2 to 63 Ips (30 to 100 gal
per hour).
e. Coagulant feed equipment = dry feeder for up to
1,300 kilograms per day (2,800 pounds per day) of
alum.
f. Flocculant mixing equipment = 1,900 1 (500 gal) mix
tank and two hp motor with mixer.
Flocculator
a. Over and under baffled channel.
b. Construction = reinforced concrete.
Sedimentation Chamber - Same as for mill ponds except:
a. Two parallel units with one common wall.
b. Size, depth = 3.7 m (12 ft), width = 3.7 m (12 ft),
length = 15.2 m (50 ft).
House for feed equipment and chemical storage.
a. A metal building.
b. Size = 12.2 m (UO ft) x 12.2 m (UO ft).
c. One double door, one single door, two windows,
lighting, exhaust fan, concrete pad, cold water
taps, drain, no sanitary facilities.
Sludge disposal.
a. Same as mill ponds only larger.
b.
c.
d.
e.
Pond size 2.1 m (7 ft)
square.
deep, 67.1
m
(220 ft)
Overflow weir a 2 m (7 ft) depth
Annual cleaning.
Hauled to sanitary landfill.
Alternative D - Alternative D consists of applying filtration and
activated carbon treatment to the effluent from Alternative C.
Therefore, Alternative D1 consists of the equalization basin
designed for Alternative B1 and C1, and Alternative D2 consists
of the chemical treatment system designed for Alternative C2.
Alternative D3 is a filtration unit utilizing gravity flow.
Pressure filtration was not used in this case because of the
large size of the units required. Alternative DU is an activated
carbon system similar to that designed for mill pond effluents.
231
-------
except that in this case the rate of carbon consumption is
sufficient to justify on-site regeneration. Therefore, three
units are provided, two to operate in series while the third is
recharged.
The removal efficiencies for Alternatives D1 and D2 are the same
as for Alternatives C1 and C2, respectively. The removal
efficiencies for Alternative D3 are 20 percent and 90 percent for
COD and suspended solids, respectively. The removal efficiency
of Alternative DU is 75 percent for COD.
Alternative D is illustrated in Figure 53, The following design
criteria are employed:
1. Filtration unit
a. Gravity sand.
b. Two boxes of reinforced concrete each 3.0 m (10 ft)
wide, 10.7 m (35 ft) long, and U-6 m (15 ft) deep.
c. 76 cu m of silica sand - effective diameter = 0.5
mm and uniformity coefficient = 1.5.
d. Underdrain = graded gravel.
e. Feed pumps are assumed to be unnecessary.
f. Backwash pump 331 Ips (5,250 gpm » TDH=7.6 m (25
ft).
g. Backwash water treated in sludge settling pond with
other sludge.
h. Housing = increase coagulation and chemical storage
building to 18.3 m (60 ft) x 18.3 m (60 ft).
2. Activated Carbon
a. Same as mill ponds except for size and necessity
for pumping.
b. Three tanks 3.0 m (10 ft) diameter, 4.0 m (13 ft)
tall.
c. Provide for 1,400 kg (3,000 Ib) of activated carbon
per day.
d. This dose rate is within the regeneration range.
Therefore, provide a carbon regeneration system.
e. House regeneration equipment - make existing
building 18.3 m (60 ft) x 2U.U m (80 ft) .
232
-------
LOG POND
EFFLUENT
EQUALIZATION
OXIDATION
POND
OXIDATION
POND No. 2
MIXING
CHEMICALS
FLOCCULATION
SLUDGE
SEDIMENTATION
SLUDGE
POND
FILTRATION
SAND
UNDERDRAIN
BACKWASH WATER
BACKWASH
PUMP
RECHARGE
ACTIVATED
CARBON
t
TREATED
EFFLUENT
FIGURE 53 ALTERNATIVE D FOR LOG PONDS
233
-------
Alternative E - Alternative E consists of the installation of
spray evaporation units directly on the log pond. Alternative E
requires U2 spray units for the model pond. The units should be
engineered to allow operation of individual units. The spray
falling on the logs would aid in preserving the logs and the logs
may increase the evaporation rate. The pond would have to be
sufficiently deep to provide a two meter (seven ft) water level
fluctuation for winter storage. The spray evaporation would be
operated 24 hours per day during the five months of operation.
With proper design and operation the pond will have no discharge
and the treatment efficiency is 100 percent.
WET DECKING
An alternative to the storage of unprocessed wood in ponds is
storage on land. To preserve land decked logs, the logs are
often sprinkled with water. The water must be relatively free of
solids in order to pass through small diameter spray nozzles.
Existing Inplant Control Measures
The most common type of water spray nozzle in use in wet deck
spray systems is the "rainbird". This nozzle delivers the water
to the atmosphere from a 0.3 cm (1/8 in) diameter rotating
nozzle. The water from this spray wets a 15 to 30 m (50 to 100
ft) diameter circle. An alternative spray system that delivers a
mist. This mist wets a 3 to 6 m (10 to 20 ft) diameter circle
and must be very close to the log surface because wind may blow
the mist away from the logs. One such installation, observed on
a warm dry day, resulted in no water discharge from the log deck.
It was all evaporating or infiltrating into the ground at the
site. While these nozzles have the advantage of producing little
or no runoff, they have several disadvantages. There must be
more nozzles used on the same size log deck and there can be
virtually no suspended solids in the water or the nozzles will
plug.
Another inplant control measure is the recycling of wet deck
water. The water discharge from the wet deck is collected in a
settling basin, sometimes as small as 9 m by 9 m (30 ft by 30
ft), which removes grit and readily settleable solids. The
clarified water is pumped back to the wet deck spray nozzles.
The fine mist producing spray nozzles usually cannot be used on a
recycled wet deck because of inadequate solids removal in the
settling pond. Water must be added to the system during dry
periods because the evaporation rate for a wet deck is
considerably higher than for quiescent waters. An overflow
structure is usually provided on the pond.
Potential Inplant Control Measures
The most effective control measure available to the operator of a
wet decking facility is the control of the volume of water
sprayed on the wet deck area. This requires strategic placement
23k
-------
of the spray nozzles and control of the periods
system is operated.
when the spray
The number of spray nozzles and, consequently, the flow of water
to the wet deck could be reduced by making the deck higher and
shorter. This may add significantly to the cost of decking,
because it would have to be performed with a crane rather than
the front-end loader that is commonly used. It would also add
significantly to the danger associated with placing and removing
logs from the deck.
The land deck could be covered and a high humidity environment
maintained under the cover. Plastic drape covers have been used
to protect roundwood stored for the pulp and paper industry, but
wind readily tears the covering from the pile. For this reason,
a firm frame for the cover material would probably be necessary.
Treatment and control Technology
The treatability of the effluent from a wet deck was assumed to
be the same as that of log pond waters since the chemical
analyses obtained in this study showed that the effluent waters
for wet decking operations are similar to those from mill and log
ponds. Therefore, the treatment technology can be considered to
be similar.
Six treatment alternatives were considered in wet decking
effluents but two different flows for each scheme are presented.
These flows correspond to those expected from a one ha (3 ac) and
a 20 ha (50 ac) wet deck. These alternatives are shown
diagramatically in Figure 54. Table 5U presents a summary of
treatment efficiencies for the treatment alternatives. The
treatment alternatives selected for the typical wet decking
operations are:
Alternative A:
No treatment, cost of small recycle pond.
Alternative B:
Recycle-equalization-sedimentation pond
Alternative C:
C1 Recycle-equalization-oxidation pond #1.
C2 Oxidation pond #2.
Alternative D:
D1 Recycle-equalization-sediment&tion pond.
D2 Chemical coagulation-flocculation.
D3 Secondary sedimentation.
Alternative E:
235
-------
ALTERNATIVE- A:
MO TREATMENT
ALTERNATIVE -
ALTERNATIVE -
RECYCLE EQUALIZATION
OXIDATION PONONoi
ALTERNATIVE - 0!
DECK J
RECYCLE EQUALIZATION
SEDIMENTATION PONO
CHEMICAL COAGULATION
FLOCCULATION
SEDIMENTATION
ACTIVATED
CARBON
FILTRATION
LTERNATIVE-F: ATMOSPHERE
S~~~\. T : ; :
Wt 1 V
OECK J
RECYCLE EVAPORATION
POND
FIGURE 54 ALTERNATIVE TREATMENT SCHEMES FOR WET DECKING
238
-------
TABLE 54
EFFICIENCIES AND CONCENTRATIONS FOR THE VARIOUS
TREATMENT ALTERNATIVES FOR WET DECKING
COD
Suspended Solids
Percent COD
Reduction in
Alternative the Unit
A
ho
Co B1,C1,D1,E1
— J
C2
D2, E2
E3
E4
Fl
0
20
60
60
20
75
100
Percent Suspended Influent
Solids Reduction Concentration
in the Unit (mg/1)
0
50
20
, 90
90
0
100
155
155
124
124
50
40
155
Effluent
Concentration
(mg/1)
155
124
50
50
40
10
0
Influent
Concentration
(mg/1 )
100
100
50
50
5
0.5
100
Effluent
Concentration
(mg/1 )
100
50
40
5
0.5
0.5
0
-------
E1 Recycle-egualization-sedimentation pond.
E2 Chemical coagulation-flocculation.
E3 Secondary sedimentation.
EU Filtration.
E5 Activated carbon.
Alternative F:
Recycle-evaporation pond.
Alternative A - There is no treatment and no removal of
pollutants for Alternative A.
Alternative B - Alternative B is the same design as Alternative B
for mill ponds and Alternative B for log ponds. The removal of
sludge from the log pond alternative must be considered. The
removal efficiencies are the same.
Alternative C - Alternative C is the same as
mill ponds and Alternative B for log ponds.
Alternative C in
Alternative D - Alternative D is the same as Alternative D for
mill ponds and Alternative C for log ponds.
Alternative E - Alternative E is the same as Alternative E
mill ponds and Alternative D for log ponds.
for
Alternative, F - Alternative F is a recycle-evaporation pond.
Evaporation ponds for wet decks of a size larger than one hectare
(3 ac) are unrealistic as a treatment technique. For this
reason, this alternative is the same as Alternative F for mill
ponds. There is no method considered to be reasonable for
achieving zero discharge or 100% treatment in wet decks larger
than one hectare (3 ac).
DRY DECKING
Some of the operational control measures applicable to wet
decking, such as the minimization of log inventories, and
alteration of deck configuration, are also applicable to dry
decks. However, since dry decked logs are only subject to
natural precipitation,, and runoff results only after sufficient
rain has fallen, the operational control measures are fewer and*
to some extent, different.
No operational control measures are currently practiced for dry
decking operations. In general, the decks are located on high,
dry ground in order to facilitate log handling during wet
weather. This has the added advantage of minimizing the amount
of surface water passing through the deck. Other efforts to
divert the flow of surface storm runoff front the log decks, such
as channelization of the runoff, can substantially reduce the
waste water stream generated by dry decks.
238
-------
Another potential control measure is
inventory to a minimum operating level.
reduction of storage
A potential method for pollutant reduction is the utilization of
greater depths in the decks. Greater rainfalls would be required
to wet the taller decks and, consequently, to produce runoff.
Covering of decks with plastic sheets or other materials is a
method of preventing polluted runoff; however, the problems
associated with this measure include: 1) the covering tends to be
blown away during winds, 2) log accessibility can be seriously
impaired, and 3) the cost would tend to be excessive for decks of
substantial size.
The end of line technology discussed for wet decks would appear
to be somewhat applicable to dry decks; however, the absence of
adequate flow information and comprehensive studies of effects of
species diversities, as discussed in Section V, precludes the
development of detailed designs for treatment alternatives for
dry deck effluents.
STORAGE OF FRACTIONALIZED WOOD
Practionalized wood, including such materials as bark, chips,
planer shavings, and sawdust, are stored in piles as waste
materials at sawmills, veneer mills, and other operations such as
insulation board and particleboard production and by-product
recovery.
As discussed in Section V, Water Use and Waste Characterization,
the retention time of the wood based material in a pile is an
important factor affecting waste water characterization and,
therefore, applicable pollution control techniques. In general,
rapid utilization of the piles, as practiced as a matter of
course at particleboard plants, is a method of pollution
reduction.
The use of fractionalized wood as boiler fuel can significantly
reduce both a water pollution problem and a solid waste disposal
problem. However, an increase in particulate emissions from the
boiler can result. An air pollution problem is also associated
with the use of Teepee burners and a widespread ban on the use of
such burners for fractionalized wood destruction has led to
extensive stockpiling of chip and particle piles.
Following a reduction of inventory to minimum levels practicable,
additional steps can be taken to reduce water pollution from
fractionalized wood piles. The practice of allowing yard storm
runoff to flow into piles can be avoided by diverting storm water
around or away from the piles. With such a diversion, the only
water generated from the piles is that originating from rainfall
directly on the piles or from their initial moisture content.
Yard runoff can also be prevented from entering piles by an
initially selection of storage sites on high, dry grounds.
239
-------
Waste water generation by fractional!zed wood piles could be
virtually eliminated by either storing the materials inside the
plant building, as is the case in some particleboard plant
operations, covering them with a roof, or placing a waterproof
material over them. Unfortunately, few plants that do not
currently store these materials inside have the ability to do so,
and/ as in the case of dry decks, covering of outside piles is
restricted by material accessibility and high cost. In the case
of long term storage, however, as indicated by McKee and Daniel
covering of piles with polyethylene may be practical and offers
the advantages of reduction of decay and opportunities of longer
storage.
It would appear that treatment technology similar to that
discussed for wet decking operations would be applicable to waste
waters generated by storage piles of fractional!zed wood.
However, although the chemical make up of the waste water is
presented in Section V, available flow data is insufficient to
allow design of treatment facilities.
LOG WASHING
Treatment and control technology as practiced in sawmills with
respect to log washing effluents consist of no treatment;
sedimentation and discharge; or sedimentation and recycle. Two
mills report total recycle of settled effluent. One of these
utilizes three rectangular steel basins in series, accomplishing
grit removal primarily, with recycle being from the third basin.
The other mill uses a dirt basin approximately 15 m (50 ft) in
diameter by two m (six ft) deep to settle 25 I/sec (400 gpm) of
log wash effluent. The effluent of the basin is recycled
following fine screening. The system has been operated
successfully for over one year. Both mills report that periodic
removal of sludge is necessary. The inclusion of adequate sludge
handling capabilities should allow maintenance of total recycle
indefinitely.
The recommended system to provide 100 percent recycle consists of
coarse screens with screen openings of about 0.64 cm (0.25 in)
for removal of large bark and wood solids from the waste water
followed by a rectangular settling basin which provides a surface
overflow of 41,000 Ipd/sq m (1000 gpd/sq ft) and a detention time
of two hours. The effluent from this tank should pass through
fine screens prior to recycle. Sludge from the settling basin
should be pumped to a sludge pond for thickening. The sludge
pond should be sized so as to require only periodic dredging and
disposal of sludge. Figure 55 illustrates the recommended
recycle system.
SAWMILLS
As discussed in Section V, exemplary sawmill operations currently
do not discharge waste water other than from log storage ponds or
storage piles of fractionalized wood (discussed separately in
2
-------
FRESH MAKEUP
—.—.INDICATES EXISTING FACILITY
•WSUMP
I- —*—— *
J^PUMP J
.TRUCK
4 LOG W<
LOG WASH j
SLUDGE HOLDING
POND
COARSE SCREEN
SUPERNATANT
SLUDGE PUMP
SOLIDS TO
INCINERATION
SETTLING
TANK
FINE SCREEN
FIGURE 55 LOG WASH RECYCLE SYSTEM
-------
this report), bark removal operations,
noncontact cooling water sources.
boiler blowdown, and
Frequently, the practice in a sawmill is to allow cooling water
to flow from the mill site in open ditches. This results in
contamination of the cooling water by sawdust, wood scraps, oil
and grease, and other substances. It can be avoided by
discharging the cooling water through closed conduits. This will
be feasible except where receiving stream flow is too low to
avoid a deterioration of water quality because of temperature
rise. It is also a frequent practice to discharge cooling water
to log ponds, especially during winter months to prevent the
ponds from freezing. This practice results in the production of
large volumes of polluted log pond water and should be avoided
unless adequate treatment of the log pond effluent is provided.
Other control techniques which lead to the elimination of
pollutant discharges from a sawmill consist of various
housekeeping measures and management practices, many of which are
current practice. Saw cooling water and chain lubricating water
usage can be minimized to avoid the production of waste streams.
This can be accomplished by the installation of special flow
control systems or by reducing the flow to the minimum required
volume. This will result in all saw cooling water being absorbed
in the sawdust.
Mill cleanup should be practiced on a frequent basis both inside
and outside the mill to avoid the buildup of bark and dust and
subsequent leaching and precipitation runoff. All cleanup can be
done without the use of water. Hog fuel piles should be covered
where possible or ditches to divert stormwater should be
constructed.
Where stains or anti-staining compounds are used, all excess
materials should be recycled and all cleanup water should be used
for makeup in subsequent batches. Dip vats should be covered to
keep out precipitation and should be equipped with an apron to
catch all drippage from dipped lumber. Any glue using operations
in the mill should adopt treatment alternatives recommended in
the fabricating operations section of this report.
In summary, the following practices are recommended and are
considered to be current utilized practice at the model sawmill:
1. Cooling water should be discharged after use in cooling
pumps, turbines or condensers by way of closed conduits
rather than open ditches.
2. Waste materials such as bark and sawdust should be
utilized wherever possible for fuel or otherwise and
should not be allowed to accumulate.
3. All stains, preservatives and coating compounds applied
to lumber should be totally contained. Where water is
21+2
-------
required for cleanup of these systems,
reused as makeup for the next batch.
it should be
U. Cleanup in and around the sawmill should be done
frequently to avoid buildup of bark and sawdust. All
cleanup should be done without water.
5. Saw cooling water usage and chain belt lubricating water
usage should be minimized.
FABRICATION
Fabrication with water soluble adhesives and associated cleanup
operations results in the production of an intermittent,
concentrated waste water. The volume of this waste water has
been shown in previous sections to be related to the number of
applicators and mixing vessels present at a particular plant. In
general, the volumes observed have been of approximately two
orders of magnitude. For most fabricating operations, the volume
of glue wash water will be in a range from 95 Ipd to 1,100 Ipd
(25 gal per day to 300 gal per day). However, for some larger
glue users, most notably the laminated structural wood products
industry, the volume of waste water produced may fall in a range
from 4,000 Ipd to 8,000 Ipd (1,000 gal per day to 2,000 gal per
day). For this reason, control and treatment recommendations and
designs are based on two distinct volume ranges.
In-Piant Control Measures
In-plant control measures to reduce the volume of waste waters
consist of various cleanup techniques. One of these techniques
consists of scraping the mixing tanks and other surfaces to
remove as much of the glue residue as possible. This technique
in combination with high pressure hoses can reduce the total
volume of wash waters appreciably. Steam or steam and water
mixtures can also reduce water usage. Steam cannot be used on
rubber rollers, but it is applicable to extruder and mixing tank
cleanup. Also, at least one fabricating operation applies a
heavy duty grease to the extruder surfaces to prevent the glue
from contacting the metal surfaces. It is estimated that with
the application of these techniques the volume of water required
for cleaning applicators can be reduced from 800 1 (200 gal) per
cleanup to less than UOO 1 (100 gal) per cleanup.
End of Line Control Technology
Present control and treatment technology for glue wash water in
the fabrication industry consists of containment in lagoons with
periodic dredging of solids with disposal to landfill,
landspread, or municipal sewers. Several treatment methods
result in no discharge of glue wash water. This can be
accomplished by screening of the larger glue solids and other
residue followed by a variety of alternatives including:
-------
1. Discharge to a shallow lagoon sized such that
evaporation and infiltration will allow total
containment. Spray evaporators may be required in some
regions of high precipitation and limited land
availability.
2. Discharge to a holding tank from which glue wash water
can be trucked to landfill, landspread, or sprayed on
hogged fuel to be burned.
3. Discharge to a holding tank from which the wash water
can be reused as wash water in cleanup operations.
Depending on the type of resin used at a particular
plant, it may be possible to use a portion of the wash
water as makeup water in glue mixing. A portion of wash
water will possibly require bleedoff which can be
handled by evaporation or incineration.
Evaporation ponds without spray evaporators are presently a
common control technique for disposal of glue wash water.
However, because of the high percentage of dissolved solids in
the resin mix, it is quite likely that zero discharge conditions
cannot be maintained in those regions where precipitation exceeds
evaporation. According to Baker, the adsorption of the dissolved
solids by soil particles causes the containment pond bottom to
become sealed and practically impermeable to water. This
disadvantage can be partially overcome by neutralization of the
waste water to reduce dissolved solids prior to lagooning.
Neutralization as a pretreatment technique has been investigated
previously for phenolic, protein and urea plywood glue waste
waters using alum, sulfuric acid, and hydrochloric acid as
neutralizing agents. The resulting titration curves are
presented in Figures 56A and 56B. These give both the volume of
titrant required to produce a given pH and the optimum pH value
for maximum COD reduction for the various glues. Figures 57 and
58 indicate that the maximum COD reduction occurs for both
protein and phenolic resins at approximately pH 7.5. While
comparable data is not available on dissolved solids, it can be
assumed that a large percentage of the total COD of the waste
water is because of dissolved solids and, therefore, that the
maximum dissolved solids reduction would occur at near neutral
pH. Tables 55 and 56 present optimum dosage levels, sludge
production rates, and cost information for neutralization of
protein and phenolic glue wastes. It should be noted that, for a
phenol glue waste, approximately 13.8 ml of 1 N H2SO4 is required
per gram of glue. Thus, assuming a U0:1 dilution of wash water
to glue, approximately 1961 Ipd (518 gal per day) of IN H2SO4
would be required for a glue waste flow of 5,678 Ipd (1,500 gal
per day). The total volume of unthickened sludge produced from
the above neutralization would be approximately 5,681 Ipd (1,501
gal per day) .
While the above information specifically concerns phenolic and
protein glue wastes, similar, though less extensive studies have
2kk
-------
1.2
tn
X
Q.
(A) BORDEN'S CASCO RESIN S-H
.7 .6 .8 .4 .3 .2 .1
ML I.ON N, OH/6M. GLUE
0 .1 .2 .3 .4 .5 .6 .7
ML I.ON H, SQ4/GM. GLUE
FIGURE 56A TITRATION CURVE FOR HARDWOOD GLUE
-------
I I I I I
ro
*-
en
x
a.
12 -I
II
10
9
e
7
6
5
4 H
9
2
(A) BORDEN'S CASCOPHEN 3i
(B) BORDEN'S CASCO s-230
i
o i
I I I I
234 56789 10
ML I.ON H2 S04/6NT GLUE
12 13 14 15 16 17
FIGURE 56B TITRATION CURVE FOR PHENOLIC AND PROTEIN GLUE
-------
10 -
9 J
8 -
7 -
6 -
X
Q_
5 -
4 -
3 -
i t i i
i t t
0 10 ZO 30 40 50 6O 70 SO 90 100 110 I2O 130 I4O
COD OR TOC, MG/GM GLUE
FIGURE 57- COD AND TOC OF SUPERNATANT VS pH FOR PROTEIN GLUE
-------
II
IO-
9 -
8 -
7 -
X
Q.
5 -
4 J
IOO 200 30O 4OO
CODv MG/GM GLUE
5OO
FISURE 58 COD OF SUPERNATANT VS pH FOR PHENOLIC GLUE
-------
TABLE 55
NEUTRALIZATION OF PROTEIN GLUE WASTE
Acid Alum Acid
(1NH2S04) {IN. A1£(S04)3-18H20) (IN HC1)
Optimum Treatment
Dosage, rnl/g glue 6.3
COD supn't, mg/g glue^
TOC, supn't, mg/g 3.2
gluei/
pH 7.9
Cost of chemicals/
100 Kg glue $0.35
6.7
19.5
9.0
6,9
$0.79
6.2
26.0
—
7.6
$0.74
5/Initial COD, 176,000 mg/gm glue
^/Initial TOC, 52,000 mg/gm glue
-------
TABLE 56
ALUM VS H2S04 FOR NEUTRALIZATION OF PHENOLIC GLUE WASTE
Acid Alum
(IN H2_S04.) (IN A12.(Sp4)3.'18H20)
Optimum Treatment Dosage,
ml/g glue 13.8
COD supn't mg/g glue^/ 67.0
pH 6.8
Total gms solids produced/
g glue 0.24
Total Volume sludge, ml/g
glue 40.0
Cost of chemicals/100 Kg glue $0.77
14.0
50.0
7.4
0.46
60.0
$1.65
-'initial COD, 653 mg/g glue
250
-------
been performed for casein and phenol resorcinol glue wastes. The
results of these studies indicate that approximately 162 Ipd (UU
gal per day) of 1 N AL2 (SOU)3 • 18H2O would be required for
neutralization of 5,678 Ipd (1,500 gal per day) of these types of
glue waste waters. These studies also indicate that the
precipitate formed as a result of neutralization will have poor
settling characteristics. Because of the obvious sludge handling
problems discussed above, neutralization will likely not be a
practicable control technology. Therefore, containment pond
design should be based on zero infiltration where neutralization
is not practiced. The assumption of zero infiltration assures
the need for induced evaporation in areas where precipitation
exceeds evaporation.
Another alternative for glue waste disposal consists of screening
and sedimentation to remove settleable solids and floating debris
followed by landspreading, landfill disposal or incineration.
Where adequate area is available, landspreading is a satisfactory
disposal method except during winter months when the ground is
frozen. Previous studies as well as observations during the
current study indicate that the glue solids are biodegradable by
soil bacteria. While the intermittent nature of the waste water
flow and the high phenolic content of many of the resins
prohibits typical biological treatment of the waste water, soil
bacteria appear to degrade the glue solids over a period of time.
Disposal by incineration was investigated by Bodien. His
results, presented in Table 57 indicate the small percentage of
non-volatile solids present in several typical plywood glue
wastes. This condition is probably typical of the glue wastes
encountered in fabricating operations. Data collected during the
current study, as presented in Table 58, indicate that the
precentage of non-volatile solids for phenol resorcinol waste
waters will be small. The conclusion can be drawn that
incineration of glue wastes at temperatures exceeding 600 C would
be a highly efficient method of reducing the volume of wastes.
Thus, where incineration facilities presently exist such as at
sawmills with hogged fuel furnaces, spraying the glue waste water
on the hogged fuel prior to burning would constitute a
practicable control technology and would result in a negligible
increase in ash presently produced.
A third alternative consists of screening and sedimentation of
the waste water followed by reuse of wash water for future
equipment cleaning. While this control method is being utilized
in the plywood industry, it is not known whether its application
would be practicable for all industrial glue wastes. This method
would probably require closer operational control than previous
control technologies so as to avoid clogging the recycle pump or
piping. Apparent advantages in the application of such a recycle
system include the fact that no reliance need be made on
hydrological conditions to insure proper control of disposal as
is the case with containment and land spreading. Reuse of the
waste water for washing may also serve to emphasize conservation
251
-------
TABLE 5-7
INCINERATION TEST FOR PHENOLIC, PROTEIN AND UREA GLUE
Based on Met Weight of Glue
% Ash @ 600°C % Ash @ 1000°C
Based on Dry Weight Glue Solids
% Ash A 600°C '% Ash £ 1000°C
Phenolic
Protein
Urea
4.58
13.37
Nil
4.12
6.12
Nil
26.08
34.48
Nil
23.40
15.76
Nil
252
-------
TABLE 58
VOLATILE SOLIDS IN PHENOL RESORCINOL WASTEWATER
Sample A
Sample B
Sample C
Total SoHds
(mg/1)
1284
5&17
1013
Total Volatile Solids
(mg/1)
886
5116
796
Non-Volatile
30
14
21
253
-------
practices because of the limited amount of storage provided in
the system and the increased costs of excessive water usage.
For some resins, a portion of the waste water may be used as
makeup for the next batch of glue. This may be the case with
various resins delivered in a dry powder form. However, the
practicality of waste water recycle for glue mixing is not
established for resins other than those utilized in the plywood
industry. Table 59 presents a comparison of anticipated wash
water flows and potential reuse of the waste water for glue
mixing of viscosity control.
A fourth alternative for disposal and a common practice is
discharge to municipal sewers. The majority of resins may be
considered compatible with municipal sewage treatment plants
either because the constituents of the waste waters are
biodegradable, because the volume is small, or both. Some
constituents may not be compatible, however, if discharged in
large slugs. This is the case, for instance, with the phenolic
resins which may contain over 500 milligrams of phenols per
kilogram of glue while phenol resorcinol resins may contain 4 to
18 percent free phenol. Many protein glues contain sodium
pentachlorophenate as an inhibitor at levels up to 0.5 percent.
Other types of resin may contain catalysts such as chromium
nitrate at levels up to 5 percent by weight. Metals such as
these may pass through a conventional secondary treatment system.
Selected Treatment Alternatives for Model Plants
On the basis of the above discussion, five alternative treatment
systems have been developed for glue wastes resulting from the
two fabrication operations modeled in section V.
Alternative A consists of no treatment and control and results in
no reduction benefits or costs.
Alternative B consists of screening and discharge to a spray
evaporation pond. Screening is accomplished in this and all
remaining alternatives by a 38 cm (15 in) rotating screen with
2.00 mm (0.1 in) screen openings. The screened effluent is then
discharged to a pond sized such that spray evaporators operating
five months per year contain the waste flow and rainwater
completely. The evaporators consist of a pump, piping, spray
nozzles, and a flotation system. A schematic of the system is
presented in Figure 59. Table 60 presents design information
concerning the proposed treatment system.
Alternative C, incineration, consists of screening, storage and
the necessary pump and piping to spray the wastes onto hogged
fuel prior to burning. This alternative assumes the existence of
a hogged fuel furnace.
Alternative D, landspreading of the glue wastes, consists of
screening, storage and trucking to landspreading or landfilling.
A schematic of Alternatives C and D is given in Figure 60.
25lt
-------
TABLE 59
POTENTIAL MAKEUP WATER VS. WASTEWATER PRODUCTION
Mill
A
B
C
D
Type of
Product
Garage Door
Beams
End- Jointed
Lumber
Beams
Beams
Decking
End-Oointed
Lumber
Decking
Type of
Glue
Poly vinyl
Phenol
Resorcinol
Polyvinyl .
Phenol
Resorcinol
Phenol
Resorcinol
Phenol
Resorcinol
Phenol
. Resorcinal
Mel ami c
Urea
Wastewater
Production
(I/day)
380
190
190
380
4500
2300
3800
Potential Makeup
Water
(I/day)
4
19
4
68
125
110
255
-------
____ INDICATES EXISTING FACILITY
GLUE SPREADER
FINGER JOINTER
MIXING TANKS
1
200mm SCREEN
STORAGE LAGOON
PLANT - I
FLOW = 757 (pd
SPRAY EVAPORATION WHERE NECESSARY
PLANT-2
FLOW = 5678 Ipd
SPRAV EVAPORATION WHERE NECESSARY
FIGURE 59 ALTERNATIVE B FOR GLUE WASTE DISPOSAL
256
-------
TABLE 60
SPRAY EVAPORATION POND DESIGN ALTERNATIVE B
Northwest Region
Precipitation - 259 cm/year
Evaporation - 61 cm/year
Plant 1
"Flow - 760 liters/day
Lagoon Size - 11 x 11 x 3 meters deep
Spray Evaporators - One twenty horsepower unit, operating
six hours per days five months per year,
:PI ant 2
Flow - 5680 liters/day
Lagoon Size - 30 x 30 x 3 meters deep
Spray Evaporators - One seventy horsepower unit operating
eleven hours per day, five months per
year.
North Central Region
Precipitation - 84 cm/year
Evaporation - 76 cm/year
Plant 1
Flow - 760 liters/day
Lagoon Size -9x9x3 meters deep
Spray Evaporators - One twenty horsepower unit, operating
three hours per day, five months per year.
Plant 2
Flow - 5680 liters/day
Lagoon Size - 23 x 23 x 3 meters deep
Spray Evaporators - One seventy-five horsepower unit.
operating six hours per day, five months
per year.
New England Region
Precipitation - 94 cm/year
Evaporation - 64 cm/year
Plant 1
Flow - 760 liters/day
Lagoon Size - 8 x 8 x 3 meters deep
Spray Evaporators - One twenty horsepower unit, operating
three hours per day, five months per
year.
Plant 2
Flow - 5680 liters/day
Lagoon Size - 22 x 22 x 3 meters deep
Spray Evaporators - One seventy-five horsepower unit,
operating six hours per day, five
months per year.
257
-------
Southwest Region
Precipitation - 38 cm/year
Evaporation - 147 cm/year
Plant 1
FTow - 760 liters/day
Lagoon Size - 11 x 11 x 0.6 meters deep
Spray Evaporators - One twenty horsepower unit, operating
1.5 hours per day, five months per year.
Plant 2
Flow - 5680 liters/day
Lagoon Size - 30 x 30 x 0.6 meters deep
Spray Evaporators - One twenty horsepower unit, operating
eleven hours per day, five months per year,
Southeast Region
Precipitation - 127 cm/year
Evaporation - 112 era/year
Plant 1
FTow - 760 liters/day
Lagoon Size - 8 x 8 x. 3 meters deep
Spray Evaporators - One twenty horsepower unit, operating
twenty hours per day, five months per year.
Plant2
Flow - 5680 liters/day
Lagoon Size - 21 x 21 x 3 meters deep
Spray Evaporators - One seventy-five horsepower unit,
operating six hours per day, five months
per year.
258
-------
INDICATES EXISTING FACILITY — — — — — —
GLUE SPREADER |
Fl N6ER JOINTER |
MIXING TANKS I
I
I
2
00mm SCREEN
HOLDING TANK
1
r
TRUCK TO
LANDFILL
^
r
TRUCK TO
LAND SPREAD
r
SPRAY ON
HOGGED FUEL
PLANT - t
FLOW = 757!pd
HOLDING TANK VOLUME = 7570 liters
PLANT- 2
FLOW = 5678 Ipd
HOLDING TANK VOLUME = 3?850 liters
FIGURE 60 ALTERNATIVES C AND D FOR FABRICATION
259
-------
_-_-__ INDICATES EXISTING FACILITY
PUMP
MIXING TANK
GLUE SPREADER
FINGER JOINTER
I
2.00mmSCREEN
HOLDING TANK
BLEEDOFF TO
INCINERATION OR
LAGOON
SUMP
MAKE-UP WATER
PLANT- I
PUMP FLOW = 757 lpd@J3.7otm (INTERMITTENT)
HOLDING TANK VOLUME a 3785 lltirs
PLANT - 2
PUMP FLOW - 5,678 Ipd fl 3.7atm (INTERMITTENT)
HOLDING TANK VOLUME = 18.925 liter*
FIGURE 61 ALTERNATIVE E FOR GLUE WASHWATER REUSE SYSTEM
260
-------
Alternative E, wash water recycle, again consists of screening
and storage. The settled and screened effluent is then utilized
for subsequent washing operations. A sump and sump pump are
provided as is a capacity for makeup water to the system and
bleedoff from the system. Provision is also made for use of the
waste water in glue mixing where feasible. This system is
presented in Figure 61.
Alternative F is applicable for urban fabricating operations and
consists of discharge to a municipal sewer.
INSULATION BOARD
The treatment and control method currently in use in all plants
consists of primary clarification only. Other systems in use
include activated sludge, aerated lagoons, spray irrigation,
sedimentation, coagulation, and water recycle. There are also
two plants currently discharging into municipal treatment
systems, with three others scheduled to do so in the near future.
Inplant Control Measures and Technology
There are various means by which waste water flow and loading
from an insulation board plant may be reduced. However, some of
these methods are either not practical or not applicable to every
plant because of variations in inplant processes or products
produced. As discussed previously in section V, and shown
graphically in Figure 40, steaming pressure, and time have an
influence on the BOD loading from a given process. While the
reduction of the severity of steaming may reduce waste water
loads, there is a counter-effect of increased cost of defibrating
as well as a decrease in the quality of the resulting fiber.
Full scale plant tests in Sweden have shown a BOD load reduction
of up to 50 percent with reductions of steaming pressures from 15
atmospheres to approximately 7 atmospheres.
Studies in Sweden on the economics of decreasing steaming
severity show that there is an approximate increase of up to
$1.50 per metric ton when the steaming pressure is reduced by
this amount. Although these costs may differ from one plant to
another depending on the extent of modification of existing
equipment, they are considered sufficiently valid to reflect the
increase in energy consumption, the purchase of extra refining
equipment, and the reduction of steam consumption.
It was also found in the study that there is a decrease in
internal bonding strength in the finished board when steam
reduction is done outside of certain ranges. It was concluded
that the quality of pulps produced within a range of six to
twelve atmospheres of steam pressure (70 to 160 psi) are about
the same; however, reduction in steaming pressure below this
range produces fiber of lower quality. In addition to a decrease
in the internal bonding properties of the board, there has also
been noted a decrease in the resistance to water absorption and
an increase in swelling properties of the final board. Most
261
-------
plants in the U. S. already operate below 11 atmospheres,
therefore, they are discharging less BOD load than if they were
operating at a higher steaming pressure.
The elimination of steaming completely (or the reduction of steam
pressures to under two atmospheres (29 psi) cannot be considered
a viable alternative to reduced waste water loads as this will
change the characteristics of the fiber produced which in turn
will affect the following operations and have considerable effect
on the final product. In addition, there are certain species of
wood such as oak which could no longer be utilized if steaming
were to be eliminated. Therefore reductions or elimination of
steaming on an industry-wide basis is not considered an
alternative for BOD reduction, although each plant may want to
consider it on an individual basis.
As discussed in Section V, all insulation board plants practice
some degree of process water recirculation. It is also typical
of the industry to practice some degree of reuse of other waters.
The major effect of closing a process water system is the
reduction of the total amount of suspended solids (fibers and
other fine suspended substances) in the discharge stream. It has
been shown that the concentration of suspended solids in the
waste water is approximately the same regardless of the total
volume of waste water discharged. Thus the total pounds of
fibers and other suspended substances discharged will be roughly
proportional to the volume of the waste water discharged.
Although it has been shown that plants with closed water systems
have lower pollution loads than plants with open systems, only
when a process water system is closed to a discharge of less than
2000 1 per metric ion (500 gal per ton) will a significant
decrease in BOD load occur. A decrease in the volume of waste
water discharged from 50,000 1 per metric ton to 10,500 1 per
metric ton (12,000 gal per ton to 2,500 gal per ton) reduces the
amount of solubles (the major contributor to BOD) by only eight
percent in the waste stream. Plants in the U. S. usually recycle
water by such systems as are shown in Figures 62 and 63.
There are limitations to the amount of recirculation which can be
done by any given plant. When a process water system is closed,
there is usually a buildup of dissolved solids and, to a small
extent, suspended solids, as well as a decrease in pH and an
increase in temperature of the process water system. These
factors affect both the economics of the process and the quality
of the final product. Also, as these effects occur, there is
further hydrolysis of some of the dissolved solids to lower
molecular weight material, thus increasing the BOD per unit mass
of dissolved solids by hydrolyzing the colloidal fiber into a
dissolved state. The dissolving of the colloidal fiber would
eliminate any possibility of a substantial portion of it being
removed by chemical coagulation.
262
-------
TO ATMOSPHERE
I03f
N>
WOOD
(50)
LJ
(25)
__________________
LjJ DECKER LJ
REFINING STOCK CHEST DECKER STOCK CHEST
(I) {(15)
!
i
LJ ^^^ LJ
(1.5) | (50)
I
DRIE R Unite* TO FINISHING
PROCESS WATER CHEST
»- WATER IN
*• WATER OUT
(X) APPROXIMATE FIBER CONSISTENCY
IN PROCESS
* 1
FRESH WATER ' -^ TO TREATMENT
FIGURE 62 WATER RECYCLE SYSTEM TYPE I FOR INSULATION BOARD
-------
TO ATMOSPHERE
en
WOOD
J REFINING ^JsTO
(30) (25)
-. ^ WATER IM
*
1
1
CK CHEST ^J DECKER U STOCK CHEST ^J K!SJ!« ^^ DRIER 1
^^^^ ^^^^1 ^^^^1 Pn«^niP|C ^^^^^ |
(I) j 05) ' (1.3) j
* *
FIBER MACHIN
WHITEWATER WAT£fl
. C?,FSJ._ * — - — CHesT
1 '
1
L — *-TO TREATMENT
(50)
E
(98)
TO FINISHING
-- ». WATER OUT
(X) APPROXIMATE FIBER CONSISTENCY IN PROCESS
FIGURE 63 WATER RECYCLE SYSTEM TYPE II FOR INSULATION BOARD
-------
As the process water system is closed, there is an increase in
the concentration of soluble substances (dissolved solids) of
both organic and inorganic nature. Because there is over 50
percent moisture in the mat entering the dryer, a higher
concentration of dissolved solids in the process water would mean
a proportional increase in the amount of dissolved matter leaving
with the board. During the drying operation, there is a tendency
for the wood sugar and other dissolved organics to migrate to the
surface of the board. The presence of these soluble organics on
the surface of the board causes problems when a dry board is
coated. When a dissolved solids concentration reaches a certain
point, the amount of organics on the surface of the board is so
great that when a coating is applied, a discoloration may occur.
The presence of these dissolved organic materials on the surface
will cause problems during the rehumidification stage of the
process. In some plants, the board is coated with a spray of
water and then sheets are stacked on top of one another to allow
the moisture to become uniformly distributed within the board.
When the amount of organic material on the surface is too large,
a lamination between boards causes entire stacks of board to
stick together. A buildup of inorganic dissolved solids in a
system may cause a case hardening effect in the board as it is
dried. That is, there will be a less efficient utilization of
heat in the dryer and more energy will be required to reduce the
moisture content in the board to the required level. It has been
noted in one plant, which is currently in the process of
attempting to close its process water system, that an increase in
weight of the board occurs and also the water resistance is de-
creased, thus creating a need for more size to be added to the
final product. The critical amount of dissolved solids that can
be tolerated by any given plant will vary considerably. It has
been reported by industry that the maximum concentrations of
organic dissolved solids that can be tolerated range from 0.5
percent to as high as 1.8 percent, depending on the plant
involved. In general, a higher concentration of dissolved solids
can be tolerated in sound deadening board as compared with
sheathing board and a higher concentration can be tolerated in
sheathing as compared to finished products. Those plants
producing hardboard, in addition to the above problems, encounter
sticking in the press when the dissolved organic concentration is
excessive. The concentrations that can be tolerated by these
systems will also range from approximately 0.5 percent to about
1.8 percent.
As mentioned above, there is an increase in temperature when the
process water system is closed. The increase in temperature may
cause hot and humid conditions near the forming machines and lead
to unpleasant working conditions. The high temperature may also
affect the additives that are added to some boards. For
instance, when molten asphalt is added in sheathing production,
it usually becomes crystalline when it contacts the process water
stream. It is necessary that this occur in order to produce
sheathing of high quality. However, if the temperature of the
process water becomes too high, the asphalt remains in a molten
265
-------
state causing a degradation of product quality. Increasing
recycle not only increases the temperature but causes a drop in
pH. Aside from the increase of chemical hydrolysis as discussed
above, a drop in pH to approximately U.O increases corrosion of
pipes and other machinery.
A closed process water system is a media that encourages
biological growth. It has been noted that slime growth occurring
on screens throughout the system affects the forming operation
and other screening necessary in the process. Slime buildups on
machinery other than screens may be broken off and formed into
the mat. When the mat is dried the slime causes an imperfection
in the board and sometimes causes a cavity to appear. This again
makes the board unsalable.
Although the actual concentration of suspended material may not
increase significantly in a closed white water system, the
percentage of fine material will. The buildup of these fine
suspended solids causes a decrease in the draining rate of the
stock. This will cause a slowing down of the production process,
or an increase in the weight of the board. This is an
undesirable effect since the board is sold on a square foot basis
and shipped on a weight basis.
In a plant producing multiple products on multiple lines with a
common pulping system, there are further restrictions on the
reuse of process waters. This is because of an incompatibility
of certain additives used in producing one product with another
product. In general, as shown in Figure 6U, the process waters
from the finished board (ceiling tile, etc.) and mineral fiber
white water systems are interchangeable and can be utilized in
all other product water mixes. The process water from a
hardboard machine can be utilized in the process water of a
sheathing machine and sound deadening board. The process water
from sheathing production can be utilized only in making sound
deadening board.
Despite the limitations mentioned above, there are methods to
increase the amount of water that can be recycled which in turn
reduces the waste water flow and, in some cases, the pollutant
load as well.
One method of achieving a decrease in waste water flow is to use
a split recycle system as shown in Figure 63. This system breaks
the water usage at the decker with the fiber preparation white
water being held separate from the machine white water system.
This system enables the reduction of pollutant flows but not
necessarily the waste water loads from a process. The principle
of this system is to keep the dissolved solids that are released
during the steaming process from entering the machine white water
system. This enables a plant to reduce the waste water
discharge, which might be advantageous for spray irrigation, to
concentrate the waste water stream if evaporation is being
considered, or to reduce the flow and save money on clarifier
costs, if a biological system is to be used, while at the same
266
-------
or
MINERAL
FIBER
BOARD
j
1
i
U
i
i
j
-*V^^^
Fl N IS H E D
(DECORATIVE)
TILE
f
HARDBOARD
M.
L. ._
i
i
SH
D. SIDING
i
•
EATHING
N
'
'
*
i
•
'
'
i
'
L*. (BLACK)
BOARD
'
'
^E^-y*-1
1 • -^^
'
SOUND
DEADENING
BOARD
t j
.
FIGURE 64 COMPATIBILITY OF PROCESS WATERS OF VARIOUS PRODUCTS -
INSULATION BOARD
-------
time control the dissolved solids concentration being built up in
the machine white water system. This would eliminate or greatly
reduce the problems associated with dissolved solids buildup in
the machine white water system discussed above. There are
limitations to this system. It is not applicable for a multi-
product, multi-line plant which uses a combined pulping system,
as recycled water from the sheathing line may come in contact
with the fiber destined for the ceiling boardline, thus
contaminatng the board. If separate pulping systems are used
this is not a problem. There is the possibility for an increase
in temperature and lowering of pH in the fiber preparation white
water system. This can be eliminated by using stainless steel
piping and installing a heat exchanger.
Another method of reducing water discharge is to use a primary
clarifier and recirculate a portion of the clarified water back
to the system. This is currently being done in a number of
hardboard and insulation board plants with promising results.
There is also some pilot scale work being conducted on the use of
coagulants and flotation clarifiers to enable a more closed
system to be achieved. The use of calcium hydroxide, followed by
aluminum sulfate with a high ferric sulfate content has been
shown to reduce the chemical oxygen demand of process water
systems by about 30 percent over a rather wide range of pH
conditions. This reduction is principally the result of the
removal of some of the higher molecular weight dissolved
organics. Various coagulation processes have been tried both in
the O. S. and Europe in an attempt to increase recycle and reduce
BOD loads. The results have not been particularly successful
with only a small percentage of the plants installing a full
scale process.
Other methods for increasing the amount of water that can be
recycled by attempting to remove the suspended solids. These
include 1) the use of a Saveall or 2) a diatomaceous earth
filter. The diatomaceous earth filter utilizes coagulation to
increase solids removal by the filter. Solids reduction from
2000 or 3000 mg/1 down to 200 or less are reported to be common.
The practical application of this system has not been adequately
tested, but it can be assumed that it can be used to reduce the
waste water discharge, A schematic of a summary of the above
treatment systems is shown in Figure 65.
There is currently one plant recycling secondary effluent to the
process and another plant planning to do pilot work in the near
future. In these systems, the effluent from the plant goes
through a biological treatment system (activated sludge) and the
effluent from the secondary clarifier is recycled to the process.
The use of a biological treatment system enables a considerable
reduction in the organic material in the waste stream. A system
of this type would reduce limitations imposed by high
concentrations of dissolved solids of organic nature. However,
the plant currently recycling from the secondary clarifier has no
long term data and thus the effect of the buildup of inorganic
268
-------
TO ATMOSPHERE
WOOD
CO
REFININ6 I"MM| STOCK CHEST
i
WATE
WAT
.
MMH
DECKER
:R IN
•R OUT
i
MM
STOCK CMCSTpMM
i
I
*
PROCESS
WHITE
FORMING"———
MACHINE J~™
1
_J
I — -
J
WATER CHEST
£
DRIER UMMJ
SOLIDS REMOVAL
(1)
(2)
(31
TRFATUFMT
FILTRATION
FLOTATION
SEDIMENTATION
1
TO FINISHING
FIGURE 65 SCHEMATIC OF SUSPENDED SOLIDS REMOVAL FOR
PROCESS WHITE WATER RECYCLE IN INSULATION BOARD PLANTS
-------
dissolved solids has not been adequately studied. Members of the
industry indicated that recycle of a portion of the secondary
effluent is a practical idea. However, the problems of suspended
solids overflowing the clarifier must be solved, possibly by
mixed media filtration. The effect of the buildup of inorganic
solids on a long term basis must be studied before a large scale
utilization of this scheme is employed.
There are other possible places where water may be reused in a
system to reduce water usage. These include but are not limited
to the use of cooling water and seal water as process makeup
water and the reuse experimentally of clarified effluent from a
primary or secondary clarifier as seal water. A summary of water
reuse possibilities is presented in Figure 66 for a typical
plant.
End-of-Line Treatment Technologv
Existing end-of-line waste water treatment technology in the
insulation board industry varies considerably within the
industry. There are plants with no treatment and plants with
zero discharge. The existing systems can be considered
conventional and usually consist of primary clarification
followed by a type of biological treatment. Each of the existing
processes presently being used is discussed below and presented
in Table 61.
Primary S edimentati on - The removal of suspended solids by
primary sedimentation is the basic process utilized for waste
water treatment in most plants. At least 13 plants utilize
primary settling tanks or ponds as part of their treatment
system. Overflow from primary settling may be discharged to
receiving streams, to municipal treatment systems, or to further
treatment on site. A portion of the overflow may also be re-
cycled for inplant use. Suspended solids removal efficiency data
are available from only two insulation board plants which report
approximately 50 and 85 percent efficiency, respectively.
Because most of the BOD in the waste water from an insulation
board plant is dissolved solids, BOD removal by primary
sedimentation is only approximately 10 percent.
Handling of sludge from the primary settling units is a major
problem. Some plants reuse a small portion of the sludge in the
production of board; however, the quantity of sludge reused is
dependent on many factors and is not a dependable method for
sludge handling. Therefore, adequate means of sludge handling
must be available at all plants. The only mechanical sludge
dewatering process reported to be used in the insulation board
industry is vacuum filtration. Final sludge disposal with or
without prior dewatering usually consists of lagooning or land
disposal.
Activated Sludge - Three plants are utilizing activated sludge
systems for a portion of their waste water treatment. Table 62
shows the average efficiency of these treatment systems. Average
270
-------
COOLING
, WATER
\
1
\ *
\ WA
/
1 *
r— *
r
AL /
CHIPWASH
" •<*-
t;.
r^n
FIBER
PREPARATION
WHITEWATER
t—
r
MACHINE
WHITEWATER
( INCLUDING
BROKE)
.. *
i
FINISHING
0, 0
"i
1
(EXPERIMENTAL)
4 .. rt n_ _.._r^_ n-
' 1
J
1
I
_ J
k SCRUBBER
>
i
i
1
1
?„
; '
\
i
i
i '
"
<-D—
1
1
D ' '-
,
1
D ^
1
:
1 1
:
r, ^
^ ^ / ' \
J ! 1
1 1
i i /**>^"S\
-™"° D™"fpR 1 M A R Y I
(
SECONDARY
(EXPERIMENTAL
'
FIGURE 66 WATER REUSE POSSIBILITIES FOR AN INSULATION BOARD PLANT
271
-------
TABLE 61
EXISTING TREATMENT TECHNOLOGY IN THE INSULATION BOARD INDUSTRY
PLANT NO.
1
3
4
5
6
7
9
10
11
12
. 13
14
15
16
17
18
19
20
EXISTING WASTEWATER TREATMENT
To Municipal System
Spray Irrigation
Primary Settling
Primary Settling, Spray Irrigation,
or Lagoon
Primary Settling
Primary Settling, Activated Sludge
Primary Settling
Diatomaceous Filter*
None
Primary Settling, Activated Sludge
None
Primary Settling, Aerated Lagoon,
Lagoon
Spray Irrigation
Aerated Lagoon, Secondary Clarifier*
To Municipal System
Primary Settling, Lagoon*
Primary Settling, Lagoon, To Municipal
System
To Municipal System
*These systems involve experimentation with complete reuse of the
treatment system's effluent.
272
-------
TABLE 62
EFFICIENCY OF BIOLOGICAL TREATMENT PROCESSES
EFFLUENT
INFLUENT
lant
7
9
12
BOD
Kg/KKg
11.6
15.1
15.1
SS
Kg/KK
11.
14.
4.
BOD
BOD Removal
q Kg/KKG Eff.
Activated Sludge
8 2.6
1 2.8
2 1.4
Aerated Lagoon
78%
83%
91%
SS
Kg/KKg
24.5
4.2
3.9
SS
mg/1
1027
359
424
SS
Removal
Eff.
0%
70%
8%
16*
6.5
0.2
68
77%
14
44.6
52.3
2.8
94%
1.0
98
* 50+ Day D.T.
273
-------
BOD reductions vary from 78 to 91 percent and suspended solids
reductions vary from zero to 70 percent. There is little
question that a properly designed and operated activated sludge
system can provide an average BOD reduction of 90 percent. At
least two hardboard mills which have similar waste water
characteristics are achieving greater than 95 percent BOD removal
with activated sludge processes.
The efficiency of biological systems for removing suspended
solids appears quite low because of the high concentrations of
biological suspended solids in the effluent and the fact that
these solids are difficult to settle and dewater. There is
presently no economical method that is satisfactory for handling
waste activated sludge generated by insulation board waste water
treatment systems. The difficulty of handling waste solids
causes a build up within the treatment system, a resulting
discharge of solids in the effluent, and the characteristically
low efficiency of the system for suspended solids removal.
Furthermore, ambient temperature are reported to have an effect
on the settling rate of biological solids in biological treatment
systems.
Figures 67, 68, 69, 70, and 71 show the variation in the monthly
average effluent BOD and suspended solids for plants 7, 9, 12,
1U, and 16, respectively. The major significance of these
figures is the illustrated variation in effluent composition and
high suspended solids in the effluent.
Aerated Lagoons - Two plants report utilization of aerated
lagoons as part of a waste water treatment system. Plant 16 has
an aerated lagoon followed by a clarifier and plant 1U has an
aerated system followed'by lagoons. As shown in Table 62, the
treatment efficiency across the total process for both of these
plants average 9U percent BOD removal and greater than 75 percent
suspended solids removal. Both of these plants are located in
areas where winter temperatures are quite cold. It should be
noted that although these two systems are technically aerated
lagoon systems, the design parameters utilized for constructing
the systems are completely different.
Lagoons - Lagoons are utilized by six plants as part of their
waste treatment system. Lagoons serve as holding ponds to dampen
variations in waste water flow and concentration, to hold waste
water during winter months when spray irrigation fields are
frozen, to serve as settling ponds for removal of excess solids
from activated sludge or aerated lagoon processes, or simply to
provide for additional BOD removal. Because of the long
detention times required, lagoons are not used as a waste
treatment system alone, but are quite effective as a part of
other systems. Because of the wide variations of waste flow and
concentrations because of inplant spills, clean-up, or equipment
malfunction, lagoons will continue to serve as an effective waste
water treatment process in the insulation board industry.
21k
-------
at
4-
o» 3-
* '
S
0
4/73-W6
o»
o>
.10
II 12 I 2 3 4 5 6 7 8 9 10 II 12 I
1971 1972
DATE
23456
1973
FIGURE 67 VARIATION IN BOD AND SUSPENDED SOLIDS FROM SECONDARY
TREATMENT IN PLANT NO. 7
-------
3LZ
M
§
Q3
M
a
I
O
O
1
wl
Of
ro
m
INH
oM
(O
-4
OJ
on
o>
80D5 Kg/KKg
ro w
CD
SUSPENDED SOLIDS Kg/KKg
-------
25
2.0
s
*
10
o
LO-
05-
BOD,
S.S/
678
MONTH (1973)
8.0
7.0
6.0
-5.0
-4.0
*
to
o
€0
"
\
LO
0
FIGURE 69 VARIATION IN BOD AND SUSPENDED SOLIDS FROM SECONDARY
TREATMENT IN PLANT NO. 12
-------
00
4.0
3.0-
o»
2-0
in
I'-5
I.OH
0.5-
0
"T— " ' I I
345
MONTH (073)
BOD.
-2.0
1.0
FIGURE 70 VARIATION IN BOD AND SUSPENDED SOLIDS FROM SECONDARY
TREATMENT IN PLANT NO. 14
-------
BLZ
BOD5 Kg/KKg
o
ro
en
i
p
s
OI-
H
-------
Spray Irrigation - Three plants presently dispose of all or part
of their wastes by spray irrigation. Plants 3 and 15 presently
dispose of all waste water by spray irrigation. Both plants have
holding lagoons that hold the waste for approximately five months
during the winter when the spray fields are frozen. Plant 5
presently disposes of a major portion of its waste by spray
irrigation and is moving toward total disposal by this method.
Two of the three plants are located in areas of relatively high
rainfall and found it necessary to install underdrain systems to
maintain a low water table and drain off excess water. The third
plant is located in a relatively low rainfall area; therefore, an
underground drainage system was found to be unnecessary. Because
of the lack of rainfall, this plant achieves essentially zero
discharge.
If land is available, if proper soil conditions are present, and
if the system is designed and operated properly, spray irrigation
can be expected to provide BOD reductions of up to 99 percent.
Inadequate land space, unsuitable soil conditions, and high costs
will prevent spray irrigation from being feasible at many
insulation board mills.
Evaporation - Evaporation of waste water can be considered either
as an end of line treatment technology or an inplant method of
water recycle. As an insulation board white water system is
closed through this recycle, the concentration of soluble and
suspended organics increase. Suspended solids can be controlled
by sedimentation or filtration; however, dissolved solids are
considerably more difficult to control.
A potential method for control of dissolved solids from the white
water systems of an insulation board mill is evaporation.
Evaporation would possibly be economical only for those plants
that steam a major portion of their furnish, i.e., subcategory
II. At the present time two hardboard plants in the U. S. and
one in Sweden utilize evaporation for treatment of a major
portion of their waste water load. The two plants in the U. S.
utilize the explosion process which results in considerable
quantities of dissolved organics. Counter-current washers are
used to remove a major portion of the organics from the fiber
prior to dilution and mat formation. The waste is discharged to
a clarifier and the overflow goes to a multi-effect evaporator.
The concentrated organic stream from the evaporator is either
sold as cattle feed or incinerated. The condensate is either
reused as process water or discharged as a waste water stream.
The Skinnskattenbergs Bruk plant in Sweden presently evaporates
all of its waste water discharge from the white water system. A
five-effect evaporator is utilized to evaporate 30 cu m (7,900
gal) per hour. Slowdown from the white water system has a total
solids concentration of 2.7 to 3.2 percent and is evaporated to
approximately 30 percent solids. The concentrated material is
then burned along with sander dust in a boiler.
280
-------
At the present time, no insulation board plant is known to
utilize evaporation for waste water treatment although at least
one plant in the U. S. is considering this type of system. The
major question concerning the use of evaporation in the
insulation board industry is economics. The cost of evaporation
is directly related to the quantity of water to be evaporated
which is in turn related to the concentration of dissolved
organics in the white water system as discussed previously.
Evaporation cannot be recommended as a viable treatment
alternative for every insulation board plant as a detailed
feasibility study and cost estimate should be conducted for each
plant to determine its applicability.
Selection of Control and Treatment Technology for Model Plants
In Section V, model plants were developed for each of the
insultion board subcategories. The subcategories and definition
of waste water flow and composition are summarized as follows:
Subcategory Liters/kkq
I 12,500
II
12,500
Flow
cu m/day
3400
3UOO
BOD
kq/kkg
12.5
37.5
SS kq/kkcr
10
10
Each of the model plants is assumed already to have a primary
clarifier in use because all insulation board plants either have
primary clarification or the equivalent.
Except where noted the following treatment alternatives
applicable to both insulation board subcategories:
are
Alternative A - Alternative A assumes no additional treatment and
control technology
Alternative B - Figure 72 shows a schematic diagram of
Alternative B. This alternative consists of adding an aerated
lagoon followed by a small settling lagoon to Alternative A
above. The detention time of the aerated lagoon was 19 days
based on the following formula:
Where:
Xo
~X
XO
X
T
K
1 + KT
influent BOD concentration, (mg/1)
effluent BOD concentration, (mg/1)
detention time in days,
constant which is dependent on the
characteristics of a particular waste
and temperature.
281
-------
FROM
EXISTING
FACILITIES
AERATED LAGOON
19DAY DETENTION
TIME
TO DISCHARGE
SETTLING
POND
24 HOUR
DETENTION
TIME
FIGURE 72 SCHEMATIC OF ALTESNATIVE B FOR INSULATION BOARD
282
-------
A treatment efficiency of 85 percent is assumed using a highly
conservative K = 0.3 at 20 C. The settling pond is assumed to
have a detention time of 2U hours. The only variation between
the design of the systems for the model plants is the quantity of
aeration which is assumed to equal 1.5 times the BOD load per
day. Sludge that settles in the settling pond is assumed to be
removed yearly and disposed of by landfill. A total BOD
reduction and suspended solids reduction of 85 and 70 percent,
respectively, are assumed across both the aerated lagoon and
settling pond. Reduction of suspended solids is based on an
assumed effluent suspended solids concentration of 250 mg/1.
Alternative C-1 - Figure 73 shows a schematic diagram of
Alternative C-1. This treatment alternative consists of the
addition of an activated sludge system to the waste water stream.
The following design assumptions were made:
Treatment process - complete mixed activated sludge
Mixed liquor suspended solids - 2,500 mg/1
BOD loading rate - 0.2 kg BOD/kg MLSS
Secondary clarifier loading rate - 20,000 1/sq m/day
Aeration requirements - 1.5 kg 02/kg BQD/day
Because of the nutrient deficiency of the waste, nutrients in the
form of anhydrous ammonia and phosphoric acid are added to the
ratio of BOD: nitrogen: phosphorus of 100:2:2. Provisions are
also made for pH adjustment as required.
Excess biological sludge is wasted to the sludge thickener. The
activated sludge is wasted at a concentration of 0.8 percent
solids and the sludge from the primary clarifier is wasted at a
solids concentration of 3.0 percent. Sludge is pumped to a
gravity thickener where the solids are concentrated to a solids
concentration of 5.0 percent. The hydraulic loading rate on the
sludge thickener is assumed to be UOOO 1/sq m/day (100 gal/sq
ft/day). Underflow from the sludge thickener is dewatered on a
pair of vacuum filters. The dewatered sludge is hauled to
landfill for final disposal. Supernatant from the sludge
thickener and filtrate from the vacuum filters is returned to the
primary clarifier.
The overall BOD removal efficiency is assumed to be 90 percent
and the suspended solids removal to be approximately 70 percent.
Reduction of suspended solids is based on ah assumed effluent
suspended solids of 250 mg/1.
Alternative C-2 - Figure 7U shows a schematic diagram of
Alternative C-2. Alternative C-2 consists of the addition of an
aerated lagoon which contains a quiescent area. The aerated
lagoon is assumed to have a detention time of eight days and will
provide an additional 70 percent BOD reduction to the effluent of
283
-------
NUTRIENT AND
pH CONTROL
1
AERATION POND
O O O
DISCHARGE
SUPERNATANT TO EXISTING
PRIMARY CLARI FIER
TRUCK TO
LANDFILL
FIGURE 73 SCHEMATIC OF ALTERNATIVES Cl AND Dl FOR INSULATION BOARD
-------
IACTIVATED!
t- w
*
j( EXISTING) |
1 1
AERATED !
LAGOON j
5-DAY J
DETENTION !
TIME ,
TO STREAM ^
*-->
OUIECENT AREA
FIGURE 74 SCHEMATIC OF ALTERNATIVE C2 FOR INSULATION BOARD
J ACTIVATEDi
J SLUDGE
.(EXISTING)!
RETURN TO
PROCESS
MIXED MEDIA
FILTER
DISCHARGE
FIGURE 75 SCHEMATIC OF ALTERNATIVE D2 FOR INSULATION BOARD
285
-------
the activated sludge system. No increase in suspended solids
removal is assumed. The overall BOD reduction for Alternative C-
2 is 97 percent and suspended solids reduction remains at
approximately 70 percent.
Alternative P-1 - Alternative D-1'consists of the addition of the
activated sludge system of Alternative c-1 to Alternative A.
Alternative D-2 - Figure 75 shows a schematic diagram of
Alternative D-2. Alternative D-2 consists of the addition of
mixed media filtration to the activated sludge process of
Alternative D-1. A surface loading rate of 160 1/sq m/min (tt.O
gal/sq ft/min) was assumed for the loading rate of the mixed
media filter. The filter is designed to handle 100 percent of
the plant effluent of 3400 cu m/day (0.9 mgd) . The reason for
the addition of a filter to the activated sludge process is to
obtain a water quality sufficient for reuse inplant. Recycle
after biological treatment is an unproven method of water reuse;
however, industry representatives feel that it may be possible.
At least one plant (No. 16) has experimented with water reuse
after biological treatment with good results. The long term
effects and the percent of recycle has not yet been determined.
Alternative D-2 assumes 70 percent recycle which results in an
overall BOD and suspended solids reduction of 97 and 91 percent,
respectively.
Alternative E - Figure 7 6 shows a schematic diagram of
Alternative E. This alternative can only be utilized by
insulation board mills in subcategory II because they steam their
furnish. Plant 4 ,also cannot use this alternative because it
uses groundwood for its raw material. Further limitations with
this alternative include that the plant either produce only one
product or, if the plant has multiple lines making different
products, each line must have a separate water system.
Alternative E requires that the process water systems be split at
the decker resulting in a white water system for the fiber
preparation system and a white water system for the machine
forming system. It also requires the installation of a multiple
effect evaporation system to handle blowdown from the fiber
preparation white water system. The condensate from the
evaporator will be used as partial makeup for the machine white
water system after pH adjustment.
The evaporator will concentrate the waste to approximately 30
percent consistency. The concentrated material is then utilized
as auxiliary fuel for producing steam. Additional fuel is
required because of the high moisture content of the concentrate.
Blowdown from the machine white water system goes to an activated
sludge process using design parameters as previously described.
Other assumptions are listed below.
1. Machine white water is used to wash
the decker.
the stock on
286
-------
TO ATMOSPHERE
4
WOOD
Co
-4
| REFINING [••J STOCK CHEST |HBB| DECKER
i ,
At
'
A
-
FIBER
PREPARATION
WHITEWATER
CHEST
(^STOCKCHEST^S.^M DRIER |__*
'
f
MACHINE '
WHITE
*~" — ' ' WAItH
CHEST
_t
OH AOJUSTMrNT
'"4
ACTIVATED
SLUDGE
1 EVAPORATOR 1
:R PLOW ».
^
TO OISCHAMC
'CONCENTRATE
FIGURE 76 SCHEMATIC OF ALTERNATIVE E FOR INSULATION BOARD
-------
2. Blowdown from the fiber preparation white water
system has a dissolved solids concentration of 1.0
percent and a flow of between 950 cu in/day (0.25
ragd) 1200 cu m/day (0.31 mgd) for subcategory II.
3. Blowdown from the machine white water system has
dissolved solids concentration of 0.5 percent and a
flow of between 830 cu m/day (0.22 mgd) and 1,000
cu m/day (0.27 mgd) for subcategory II.
4. Stock leaving the decker into the machine white
water system has water containing a dissolved
solids concentration of 0.75 percent.
5. BOD/DS ==0.6
6. Overall efficiency of the treatment system is
assumed to be 97 percent for BOD removal. Effluent
suspended solids are assumed to be 250 mg/1.
Alternative F - Figure 77 shows a schematic diagram of
Alternative F. This alternative involves spray irrigation of all
waste water from the plant. Design of the spray irrigation
system is limited by hydraulic capacity not organic load;
therefore, the system is applicable to both subcategories.
Two separate spray irrigation systems are designed because of the
temperature differences between northern climates and southern
climates. For northern climates, a holding lagoon with five
months waste water flow capacity is required because spray
irrigation cannot be practiced during freezing conditions.
Following the holding lagoon, waste water is pumped to a dosing
pond with a 3 day irrigation capacity. Nutrients as required are
added at this point. The spray irrigation system is designed on
a hydraulic loading rate of 47,000 1/ha/day (5000 gal/ac/day).
The system is also provided with an underdrain system.
The spray irrigation system for the southern climate is
essentially the same as the one for the northern climate except
that the five month holding lagoon is replaced by a 30-day
holding lagoon lagoon. A 30-day holding for southern climates is
required because at times heavy rains will exceed the hydraulic
capacity of the irrigation field.
Spray irrigation can be used by only a limited number of plants
because of lack of suitable land. If spray irrigation can be
utilized at a plant, its treatment efficiency for BOD and
suspended solids removal is predicted to be 99 percent.
A summary of the effluents produced by
alternatives is presented in Table 63.
PARTICLEBOARD
each of the treatment
288
-------
FROM
EXISTING
FACILITIES
HOLDING
BASIN
A
HOLDING
POND
3-DAY
CAPACITY
TO IRRIGATION FIELD
WITH UNDERDRAINS
FIGUEE 77 SCHEMATIC OF ALTERNATIVE F FOR INSULATION BOARD
289
-------
TABLE 63
SUMMARY OF EFFLUENTS PRODUCED BY TREATMENT ALTERNATIVES
FOR MODEL INSULATION BOARD PLANTS
BOD
Kq/KKc
SUBCATEGQRY I
Alternative
A
B
C-l, D-l
C-2
D-2
F
SUBCATEGORY II
Alternative
A
B
C-l, D-l
C-2
D-2
F
E
SUBCATEGORY III
Alternative
A
B
C-l, D-l
C-2
D-2
F
E
12.5
1.3
1.3
0.4
0.4
0.2
30.0
3.0
3.0
0.9
0.9
0.3
0.9
37.5
3.8
3.8
1.1
1.1
0.4
1.1
10.0
3.1
3.1
3.1
0.9
0.1
10.0
3.1
3.1
3.1
0.9
0.1
0.8
10.0
3.1
3.1
3.1
0.9
0.1
2.0
290
-------
The small volumes of water discharged, 11,000 1 (3,000 gal) per
day or less, from particleboard plants and the variation of waste
water sources from plant to plant have limited development of
waste treatment technology in the industry. In general, because
of the small volumes of waste water generated, the major
treatment processes are limited to waste retention ponds,
settling ponds, or a combination of retention and settling ponds.
The major waste water source in one mill may generate no
discharge in another mill. Inplant modifications for the purpose
of reducing, eliminating, or reusing waste water flow can greatly
affect total waste water discharge in any mill; however, these
are generally not applicable to all mills. Nevertheless, by the
implementation of inplant modifications and end of line treatment
technologies currently in use, the elimination of discharge from
particleboard plants can be achieved.
Inplant Control Measures and Technology
Blender Cleaning - As previously mentioned, blender cleaning can
be accomplished by either a wet or a dry method with the wet
method requiring approximately 10 times more water than the
typical dry method. There can be virtual elimination of waste
water from the dry cleaning of blenders; however, it takes
approximately four times longer to clean a blender by the dry
method because of the manual labor required. Also, there are
various types of blenders which cannot be cleaned by the dry
method. Therefore, in some mills, it is economically as well as
technically infeasible to clean a blender by the dry method.
Because the volume of water utilized in a blender varies
primarily with the rate of buildup on the interior of the
blender, it is advantageous to reduce this rate of buildup by the
use of a cooling jacket on the blender. The resins utilized by
the particleboard industry are thermosetting and a reduction in
temperature inside the blender will significantly reduce the
amount of buildup and subsequently the frequency of washing
required. However, as discussed in the description of the
particleboard manufacturing process, there are certain types of
blenders in use that are not adaptable to the use of cooling
jackets, because of the nature of the blender's construction.
Cooling Water - Cooling water in some plants is transported in
open ditches and can become contaminated with resin leaks and
fugitive particles from the plant operation. When the cooling
water becomes contaminated in this manner, the contaminants must
be removed before discharge. One method of eliminating the
pollution of cooling water is to transport it by closed conduits.
Wet Scrubbers - As mentioned previously, it is common practice in
the industry to recycle a majority of the scrubber water through
settling ponds to remove the dust and wood particles from the
waste stream. This enables a high percentage of water to be
recycled. Because there is extensive evaporation in a scrubber
system, there is a need for continuous makeup water to be added.
Various plants have reported the use of cooling water as well as
waste waters for this makeup water purpose. The evaporation of
291
-------
waste waters in the scrubbers is one method of eliminating all
discharges other than the blowdown from the scrubber.
End Of Line Technology
End of line treatment technology currently in use in the
particleboard industry, as shown in Table 64, is limited
essentially to:
1. Settling tanks
2. Containment lagoons
3. Septic tanks
4. Spray irrigation
5. Lagoons
In addition, at least one plant currently sprays its waste water
on the incoming raw materials and another on the hog fuel for its
boiler.
It is common practice for the several plants located in mill
complexes to combine their waste waters into a common treatment
system.
There are currently at least three particleboard plants that
treat waste waters in lagoons prior to discharge. Lagoons rely
on natural aeration or algae to provide oxygen to biologically
decompose organic material in the waste water. Settleable solids
undergo an anaerobic decomposition on the lagoon bottom. If
properly designed, a treatment efficiency of from 80 to 85
percent BOD removal can be realized.
Settling tanks, which constitute the most common technology in
use in the particleboard industry at this time, normally consist
of baffled settling tanks approximately 2 by 3 m (6 by 10 ft)
with a depth of 1 m (about 3 ft) or less. There is little
available data on the efficiency of these settling tanks. They
may discharge to municipal or other treatment systems, or
directly to receiving waters. The sludge from these tanks is
normally removed manually on an infrequent basis.
There is presently at least one plant (Plant 15) which uses a
septic tank for waste water treatment. A septic tank is a
settling tank in which the settled sludge is decomposed
anaerobically. Septic tanks are followed by drain fields to
allow the effluent to undergo aerobic stabilization and to
percolate into the ground. Septic tanks are suitable for
relatively low waste water flows which contain a sufficiently low
solids content that soil percolation rates will not be adversely
affected.
Spray irrigation was reported in response to questionnaires by
only one plant (Plant 16) in the particleboard industry. The
plant spray irrigates waste water in a neighboring forested area.
This method of waste water treatment utilizes the soil
microorganisms ability to decompose organic matter as well as the
292
-------
TABLE 64
EXISTING PARTICLEBOARD WASTEWATER TREATMENT SYSTEMS
Plant No.
10, 22, 23
1, 24
11, 25
26
4, 6
2
30
7
14, 18
15
5
16
20
8
3
9, 17, 31, 32
8, 10
3
Type of Treatment
Settling Tank
Settling Tank - Municipal Treatment
Municipal Treatment
Settling Tank - Containment Lagoon
Containment Lagoon
1) Settling Tank - spray on dirt roads
2) Containment
Settling Tank - Make-up for log pond
evaporation
To discharging log pond
Lagoon
Septic Tank
Spray or raw materials
Spray irrigate in woods
Lagoon - spray on sawdust landfill
Truck to landfill
Burn with hog fuel
To mill complex's system
Scrubbers
Recycle
Screen and settling pond
233
-------
soil's natural filtering ability to achieve waste water treatment
and disposal. In most cases, with proper design and operation
there is no threat of groundwater contamination. Related to this
technology is the practice of one plant (Plant 2) of controlling
the dust on its logging roads by wetting them with particleboard
waste water.
Containment lagoons are is use in numerous industrial facilities
in the timber products industry. These systems, reported in use
by a small number of particleboard plants, utilize natural
evaporation as well as seepage into the soil to dispose of waste
water. The seepage into the ground water of undesirable
substances is a possibility, and this effect must be considered
before construction.
A type of treatment, similar to containment lagoons, is spray
evaporation. The primary difference is that a spray mechanism of
some type must be installed. The waste water is concentrated by
evaporating most of the water by increasing the surface area
exposed to the ambient air by use of spray nozzles. The sludge
which accumulates on the bottom is usually disposed of in a
landfill.
At least one plant (Plant 5) sprays its entire waste water
discharge on the incoming raw material. The system consists
first of settling ponds which remove settleable and floatable
materials. The spray nozzles are activated by automatic
switching devices and, in order to maintain a uniform moisture
content on the incoming raw materials, it is sometimes necessary
to supplement the waste water flow with cooling water. Initial
work with this system has shown that the moisture content of the
incoming raw material is increased by six to ten percent.
Although this could theoretically create problems in the
subsequent inplant processes, none have been reported to date.
For example, refining has not been impaired; on the contrary,
refining has been found to improve with the higher moisture
content in the raw materials. Also, there has been no
significant increase during the first eight months of operation
of the fuel drying costs despite the increase in the moisture
content. Finally, no degradation of the final product or
incompatibility of the system has been observed because of the
waste material present in the raw material.
There are two other systems currently in use by particleboard
plants. These consist of 1) spraying of waste water on the hog
fuel, and 2) trucking waste to landfills. Spraying waste water
on hog fuel appears to be a viable alternative if the volumes of
waste are low and a hog fuel boiler is available. This system
may raise the moisture content of the raw fuel and result in more
energy being required to run the boilers. The small number of
plants that truck waste to land fills do so because inplant
equipment and process variables such as type of resin, tack, and
particle size allow a reduction of waste water flow to less than
400 1 (100 gal) per day.
23k
-------
Treatment Technology For the Particleboard Plant
The treatment technologies considered to be applicable to the
particleboard plant discharging 11,000 1 (3,000 gal) per day of
waste water as described in Section V are:
1. Discharge to municipal system
2. Discharge to a septic tank
3. Spray irrigation
4. Spray evaporation
5. Spraying of all waste water on incoming
raw material
6. Spraying of waste water on hog fuel
Containment lagoons, rely heavily on percolation to dispose of
waste water. Since the percolation characteristics of the
terrain are a major factor, the use of containment lagoons is
considered to be applicable only in certain cases and not on an
industry-wide basis. Oxidation ponds are not considered
applicable treatment technology because 1) they require large
land areas, 2) they are subject to odor problems, and 3) they do
not provide for no discharge of pollutants from the process
waters as do other more feasible methods. Trucking to landfill
may be a viable alternative for plants discharging small
quantities of water.
Description of Model Systems
Models of the treatment and control technology considered to be
applicable have been developed as follows:
Alternative A - Alternative A consists of no treatment of waste
waters and, therefore, no reduction of pollutants.
Alternative B - Alternative B consists of a septic tank utilizing
prior screening as shown in Figure 78. The screening consists of
a coarse screen and a fine screen in series. The coarse screen
has 3 mesh (0.25 in) openings, and the fine screen is a 20 mesh
screen (0.7 mm). These are flat screens and are cleaned manually
on a daily basis.
Alternative C - Spray irrigation systems, as shown in Figure 78,
are designed for two climatic areas, northern and southern. The
former area has winter conditions which produce snow and icing.
The second is for all other areas. The first system consists of
a holding pond of five months capacity, a storage tank with a
three day capacity, and a properly designed spray irrigation
field. The five month capacity of the holding pond provides for
containment of the plant's effluent during the winter months when
spray irrigation is not feasible. The three day storage tank is
used as a sump. The second type of system also has a three day
storage tank and a spray irrigation field. However, the holding
pond is of a 30 day capacity to provide for adequate storage
during periods of heavy rainfall when spray irrigation is not
feasible. The hydraulic loading rate for the irrigation fields
295
-------
SCREENS
SEPTIC TANK
J
DRAIN FIELDS
HOLDING
TANK
STORAGE
TANK
3- DAY
CAPACITY
TO IRRIGATION
FIELD w
W
FROM
PROCESS
POND
PUM P
V X X \
SPRAY
HEADS
FIGURE 78 SCHEMATICS OF ALTEENATIVES B, C, AND D FOR PARTICLE BOARD
23S
-------
is 47,000 1/ha/day (5000 gal/ac/day). Though spray irrigation
systems depend somewhat on climatical and soil percolation fac-
tors this type of system can be used in a wide variety of areas
because the treatment of the waste water (removal of pollutants)
occurs primarily because of biological actions in the soil and
the filtration by the soil of the waste water.
Alternative p - Alternative D consists of spray evaporation of
all waste water from the particleboard plant as shown in Figure
78. Systems were designed for the four climatical areas where
particleboard plants are located. These are the northwest
(Seattle area), the New England area, the southeast (Mississippi)
area, and north central (Minnesota) area. These areas were
chosen on the basis of rainfall and climate to represent.
evaporation rates to be found in the majority of the
particleboard industry. All systems consist of lined lagoons
with spray units installed.
Spray units consist of a number of spray nozzles connected to a
central 75 hp (56 kw) pump. All systems are designed such that
the spray units need to be operated only 5 months per year;
however, during the 5 month period, in some areas it is necessary
to operate the spray unit on a continuous basis and in others it
is necessary only to operate the spray unit intermittently. The
design criteria including the size of the lagoons and period of
daily operation is as follows:
Climatic
Area
Northwest
Length
m
85
Width
_m
21
Operating Time
Days
24
New England
Southeast
North Central
62
59
65
16
15
16
12
11
13
It should be noted, as indicated above, that all spray ponds are
rectangular in shape with a length to width ration of 4:1. This
design was necessary for two reasons: 1) the size and shape of
the spray units, and 2) the long axis should be perpendicular to
the prevailing wind of the area so that the maximum evaporation
can occur by preventing waste water spray from one nozzle from
being flown into the area of influence of another spray nozzle,
as this would reduce the evaporation rate and efficiency of the
unit,
Alternative E - Alternative E requires two ponds in series, each
of five day detention time, from which water is pumped to a sump.
The water from the sump is applied to the raw materials by spray
nozzles located over an existing conveying device which takes the
material from the unloading area to the storage area as shown in
Figure 79. As the raw material passes under the spray nozzles, a
trip-arm switch activates the pump from the sump and the water is
297
-------
FROM PLANT
11,000 LITERS/DAY
INTERMITTENT
5 DAY
DETENTION
TIME
5-DAY
DETENTION
TIME
FLOAT ACTIVATED
PUMP
VALVE TO ALLOW
COOLING WATER TO
60 TO SUMP IF LEVEL
OF(T)TOO LOW.
FLOAT ACTIVATED
PUMP TO FILL
SUMP.
SPRAY NOZZLE
TRIP ARM SWITCH AT fA ACTIVATES PUM
CONVEYOR.
FLOW= 19,000 LITERS/DAY
RAW MATERIAL UNLOADED
ONTO CONVEYOR
EXISTING CONVEYOR
T)WHEN RAW MATERIAL PASSES BY ON
FROM
PROCESS
z
UJ
o:
u
CO
•••
SUM P
SPRAY ON HOG
FUEL MANUALLY
FIGURE 79 SCHEMATICS OF ALTERNATIVES E AND F FOR PARTICLE BOARD
298
-------
applied to the raw materials. Between the settling ponds and the
sump, a valve i-s required too allow cooling water to enter the
sump and be applied to the raw materials. This provides for
adequate water supply to be placed on the incoming raw material
so that the raw material can have a uniform moisture content,
which is critical for production purposes. There is a float
activated valve in the second settling pond which allows for
waste water to be pumped from the pond to the sump if the level
of the pond is above a minimum depth. There is also a float in
the sump to provide for pumping from the settling ponds or
cooling water to fill the sump when the level gets too low. The
amount of water sprayed on the incoming raw material is
approximately 19,000 1 (5,000 gal) per day. This is a rate of a
little over 67 1 per metric ton {16 gal per ton) of raw material.
The plant currently utilizing this system has an application rate
over three times greater. (200 liters per metric ton)
Alternative F - Alternative F is a system for spraying all the
waste water on hog fuel as shown in Figure 79. It consists of
screens, sump, a pump, and a spray nozzle. The screens are of
the same design as described for Alternative B. The waste water,
after screening, passes to a 19,000 1 (5,000 gal) sump and is
then sprayed onto the hog fuel either while the hog fuel is in
storage or is being conveyed to the boiler.
FINISHING
Finishing operations, involving the use of water base, liquid
finishing materials, and overlaying operations involving water
soluble adhesives, require equipment washdown operations which
result in the production of an intermittent, concentrated, waste
water flow. Volumes of waste water generated from this source
vary considerably from plant to plant, but will usually fall in
the range of 75 Ipd to 1,100 Ipd (20 gpd to 300 gpd) .
Inplant Control Measures
As discussed in Section V, the cleanup techniques practiced at
any particular plant will significantly affect the volume of
waste water generated. For instance, the volume of washwater
required for a direct roll coater used in applying a waterbase
material, in most cases, could be reduced from as much as 132 1
(35 gal) per wash to as little as 19 1 (five gal) per wash. This
reduction can be accomplished by the use of only a small volume
of water initially and recycling the same water through the
applicator several times before rinsing with fresh water. It may
be possible to reuse this washwater for several cleanup
operations if the type of finishing material is not varied. The
use of high pressure nozzles to wash paint drums can reduce the
total waste water production also. However, the best inplant
control measures simply consist of the implementation of
conservative water use practices.
299
-------
End Of Line Treatment Technology
Current control and treatment technology for waste water
generated from the use of water base liquid finishing materials
and water soluble adhesives used in overlaying operations
consists of the following:
1.
2.
3.
5.
Containment in drums or holding tanks followed
by landfill disposal.
Land spread disposal.
Containment in shallow lagoons with evaporation
and infiltration.
Containment in drums or holding tanks with
settling of solids followed by reuse of the
supernate and landfill disposal of the solids.
Containment in holding tanks followed by dis
charge into municipal sewers.
These alternatives have been discussed previously for control and
treatment of glue washwater from fabricating operations.
Because of the potential soil clogging effect, as discussed for
glue wash waters in fabricating operations, containment pond
design should be based on zero infiltration with provision for
induced evaporation in areas where precipitation exceeds
evaporation. The size requirements for such ponds for five
selected regions are presented in Table 60.
Another presently practiced method of disposal for plants
generating these smaller volumes of washwater is landspreading.
Since no studies have been conducted on the biodegradability of
these materials, no conclusions can be drawn as to the extent of
degradation that is accomplished by so il bacteria in this
disposal method.
Discharge of these washwaters into municipal sewers is also a
commonly practiced method of disposal. However, because of the
great diversity in constituents of the materials, and in the
resulting waste waters, the effects of such a practice can only
be considered on an individual plant basis. Some of these
materials may contain various additives which serve as
stabilizing agents to prevent biological contamination during the
shelf life of the material. Such additives could be detrimental
to the biological processes of a municipal treatment facility.
In most cases, however, either the constituents of the waste
waters may be biodegradable or the volumes small enough, or both,
such that the waste water stream would be compatible with a
municipal treatment facility. Pigments in these materials often
contain heavy metals such as lead and cadmium which might pass
through a municipal treatment system unremoved from the treated
effluent.
Recommended Treatment Alternatives
300
-------
On the basis of the above discussion,
alternatives are recognized:
the following treatment
Alternative A
Alternative B
Alternative C
Alternative D
Alternative F
No control or treatment.
Spray evaporation.
Incineration.
Landspreading.
Discharge to municipal sewer.
The above alternatives correspond to those selected for Model 1
for fabricating with the exception that screening of the waste
water is not required. Also, Alternative E for fabricating
operations, recycle of washwater, is not a practicable technology
for finishing materials because of variations in finishing
materials. Thus, each applicator may be applying a different
material and these materials should not be mixed. Reference
should be made to the recommended control and treatment
technologies for fabrication for design details for the above
alternatives.
301
-------
-------
SECTION VIII
COST, ENERGY, AND NON-WATER QUALITY ASPECTS
This section presents an evaluation of the costs, energy
requirements, and non-water quality aspects associated with the
treatment and control alternatives developed in Section VII.
In absence of complete cost information for individual processes,
the cost figures developed herein are based on reliable actual
cost figures reported for various installations coupled with
engineering estimates. Adequate engineering estimates for a
single installation must necessarily involve consideration of a
multitude of factors. An estimate completely applicable to all
members of an entire industry subcategory is obviously
impossible. For instance, it must be realized that land costs
vary widely. While some lands associated with remote timber
processing operations may sell for under a hundred dollars per
hectare, land at an urban complex may be
price. Construction cost, in terms of
materials cost, is another element that
Therefore, the costs presented herein are intended to serve as a
guide only.
unavailable at any
both labor cost and
is highly variable.
The engineering estimates for all cost analyses in this section
employed the following assumptions:
1. Excavation cost = $1.96/cu m ($1.50/cu yd).
2. Road cost = $3.00/sq m ($2.50 sq yd).
3. Contract labor = $10.00/hr.
U. Power costs = 2.30/kw hr.
5. All costs reported in August 1971 dollars.
6. Trucking haul cost = $20.00/trip.
7. Landfill fee = $37.85/cu m ($0.1U3/gal) for sludge.
8. Landfill fee = $2.50/ton).
9. Tank truck assumed to be of 5.68 cu m (1500 gal) capacity.
10. Annual interest rate for capital cost = 8 percent.
11. Salvage value of zero over 20 years for physical
facilities and equipment.
12. Depreciation is straight line.
303
-------
13. Total yearly cost = (investment cost/2) (0.08) +
(investment cost) (0.05) + yearly operating cost.
IMPOUNDMENTS AND ESTUARINE STORAGE AND TRANSPORTATION
Cost and Reduction Benefits of Alternative Treatment and Control
Technologies
No control and treatment technology
therefore, no costs are calculated.
was formulated and.
Related Energy Requirements of Alternative Treatment and Control
Technologies
The transportation of logs via water is practiced extensively in
the Northwest. The logs are lowered or dumped into the water and
made up into rafts. These rafts may contain four or five
thousand cu m of logs. The log rafts are towed to the processing
mill by a tugboat. There are several of these raft formation
sites on the estuaries of Washington State alone, each accepting
one or two train loads of logs each day. The energy required to
transport the logs to the mill, a distance of a 160 km (100
miles) or more, via rail or truck would be significantly greater
than the energy required to transport the logs on the water. In
addition, the energy required to construct the new railways and
highways necessary to accommodate the higher traffic volumes
would be substantial.
The energy requirements for land decking of logs in relation to
water storage of logs were investigated by Schaumberg. The
results of this study are discussed in detail later in this
section but, in brief, the study showed that the energy cost to
land deck the logs only 0.8 km (0.5 mi) from the mill was far
greater than water storage at the mill site. Based on this
study, it could be concluded that the land transportation of logs
over 160 km (100 miles) with dry decking at the mill would
require considerably more energy than water transportation and
storage.
Non-water Quality Aspects of Alternative
Tec hno1oqi es
Treatment and Control
The non-water quality aspects of impoundment and estuarine
storage and transportation are primarily associated with the
alternative of removing the logs from the water. The increased
production of both solid wastes and air pollutants if land
decking were used will be discussed, but if rail or truck
transportation all the way to the mill were used, there are other
factors to be considered.
Most mills that process the water transported logs are located on
the water. In many cases, a town or city has developed around
the mill to the extent that the mill does not have room to
30i»
-------
expand. If a rail or truck terminal were to be located at the
mill site, the cost of purchasing the adjacent property might be
prohibitive. In addition, the traffic generated by this change
would have an adverse social impact.
Several studies have been performed on the loss of bark from
river and estuarine storage and transportation. These studies,
as discussed in Section V of this document, relate primarily to
water quality aspects in bark loss. Floating bark is
aesthetically displeasing and so attempts to prevent bark from
entering the water for water quality reasons will also make the
log rafting area more aesthetically pleasing. Easy let-down
devices have been observed to markedly reduce the amount of bark
lost from the logs during placement of the logs in the water.
For this reason, easy let-down devices are appearing in the
industry in more places.
WET STORAGE
The following discussion of the cost, energy, and non-water
quality aspects of treatment and control technologies applicable
to the holding of raw materials in a wet environment is broken
down into mill ponds, log ponds, and wet decking. The purpose of
this breakdown is to demonstrate the range of technologies and
the range of costs applicable to the various treatment and
control schemes.
Mill. PONDS
The effluents from mill ponds are considered to be derived from
natural precipitation. All extraneous flows to the mill pond are
considered to be routed around the mill. Various treatment
schemes are available for treatment of this effluent discharge.
Six alternative schemes were selected in Section VII as being
applicable engineering alternatives. These alternatives provide
for various levels of treatment of the waste stream from a mill
pond.
Control
and Reduction Benefits of Alternative Treatment and
Technologies
Alternative A - It is estimated that 31.5 million 1 (8.31 million
gal) of waste water emanate from the one hectare (three acre)
mill pond each year, or on the average 86,173 Ipd (22,767 gal per
day). The suspended solids load for the same waste, based on a
concentration of 50 mg/1, is 4.3 kilograms per day (9.5 pounds
per day).
This alternative requires reasonable process water use and
control in order to achieve volume limitations related to
precipitation and evaporation rates. The control of the
discharge of debris also any require production management
procedures, as discussed in Section VII to control the generation
of these materials. The physical layout and arrangement of the
305
-------
wet storage facility and the timber processing equipment also
influence the possible discharge of debris.
Because of the variety of wet storage operations as they exist in
the field, it is not possible to present absolute cost
information. The costs of achieving the proposed limitations
range between $0 and a maximum of $9,000.
control of the discharge of floating materials can be achieved by
such technologies as floating log booms, submerged weir discharge
structures, or inverted discharge pipes, or screens.
Control of debris, diameter exceeding 2.54 cm (1.0 in), is
usually achieved by installations minimizing activity near points
of discharge or by settling action that takes place in the
collection area of a wet deck recycle system.
Alternative B - The use of an equalization basin may be
appropriate for treatment of an intermittent flow. In this case,
the equalization basin is also used as a sedimentation basin.
The costs of control and treatment in Alternative B are as
follows:
Incremental Investment Costs $29,200
Total Investment Cost $29,200
Total Yearly Operating
and Maintenance $ 2,400
Total Yearly Cost $ 5,000
An itemized cost breakdown for Alternative B is presented in
Table 65.
The reduction benefits for Alternative B involves a COD reduction
of 20 percent and a suspended solids reduction of 50 percent.
Alternative Cl - This alternative is the same as Alternative B,
The costs and unit efficiency are the same.
Alternative C2 - This second oxidation pond is fed by a pump from
the first pond and, consequently, is expected to be more
effective because of the more constant feed rate.
The costs of control and treatment for Alternative C2 are as
follows:
Incremental Investment Costs $18,300
Total Investment Cost $47,500
Total Yearly Operating
and Maintenance $ 3,100
306
-------
TABLE 65 ITEMIZED COST SUMMARY OF
ALTERNATIVE B FOR MILL PONDS
Investment Costs
Items: 1. Basin
2. Pump
3. Effluent Weir
4. Engineering
5. Contingencies
6. Land (1.1 ha@ $2470/ha)
Total costs
Operating Costs
1. Operation and maintenance
2. Power Costs
Total costs
Total Yearly Cost for equalization-
sedimentation basin
$21,000
840
168
2,200
2,420
2,600
$29,228
$ 2,263
101
$ 2,364
$ 5,000
307
-------
Total Yearly Cost
$ 7,400
An itemized cost breakdown for the second oxidation pond is
presented in Table 66.
The reduction benefits for Alternative C2 include a COD reduction
of 60 percent and a suspended solids reduction of 20 percent and
the incremental suspended solids reduction is 10 percent. A cost
efficiency curve for Alternative C is presented in Figure 80.
Alternative Dl - This alternative is the same as Alternative B.
The costs and efficiency are the same.
Alternative D2 - The addition of chemicals, the flocculation, and
sedimentation of the resultant floe are all considered to be
integral portions of Alternative D2.
The costs
follows:
of control and treatment for Alternative D2 are as
Incremental Investment Cost $47,200
Total Investment Cost $76,500
Total Yearly Operating
and Maintenance $43,400
Total Yearly Cost $50,200
An itemized cost breakdown of chemical coagulation, flocculation,
and sedimentation is presented in Table 67.
The reduction benefits for Alternative D2 include a COD reduction
of 60 percent and a suspended solids reduction of 90 percent.
The incremental reduction of Alternative D2 over D1 is 48 percent
for COD and 45 percent for suspended solids. A cost efficiency
curve for Alternative D is presented in Figure 81.
Alternative El - This alternative is the same as Alternative Bl.
The costs and efficiency are the same.
Alternative E2 - This alternative is the same as Alternative D2.
and efficiency are the same.
Alternative E3 - The filtration of the effluent from Alternative
E2 pressure sand filters will provide some additional COD and
suspended solids removal.
The cost of control and treatment for Alternative E3
follows:
Incremental Investment Cost $ 36,900
Total Investment Cost $113,400
are as
308
-------
TABLE 66 ITEMIZED COST SUMMARY OF
ALTERNATIVE C2 FOR MILL PONDS
Investment Cost for Second Oxidation Pond Items:
1. Weir $ 168
2. Pond 13,020
$13,188
3. Engineering 10% 1,318
4. Contingencies 10% 1,450
5. Land 0.94ha @ $2,470/ha 2,340
Incremental Costs $18,296
Cost of Alternative C-l 29,228
Total Costs $47,524
Operating Cost for Second Oxidation Pond
1. Equipment Maintenance $ 42
2. Pond Maintenance 729
Incremental Cost $ 771
Cost of Alternative C-l 2,364
Total Cost . $ 3,135
Total Yearly Cost for Second Oxidation Pond $ 2,418
309
-------
TOTAL INVESTMENT COST (dollars)
CJ
H*
O
00
o
I
H M
o
H
O
o
o
O
o
I
O
1-9
H
§
o
o
o
3) *
m o
o
o
o
"o
o
o
i
O
O
o
w
f
o
o
I
o
o
o
I
Ul
o
b
o
o
Ul
"o
o
o
o
o
s
o
o
o
u>
o
8
3
b
8
TOTAL YEARLY COST (dollars/year)
-------
TABLE 67 ITEMIZED COST SUMMARY OF
ALTERNATIVE D2 FOR MILL PONDS
CHEMICAL COAGULATION, FLOCCULATION, AND SEDIMENTATION ONLY
INVESTMENT COST
Mixing and chemical addition
Flocculation
Sedimentation
Sludge disposal
Engineering 10%
Contingencies 10%
Land .006 + .001 + .0014 + .1933 X $2470/ha
Incremental Costs
Cost of Alternative 01
Total Costs
OPERATING AND MAINTENANCE
Flocculation
Sedimentation
Chemicals and Mixing
Building
Sludge Disposal
Power
Incremental Cost
Cost of Alternative Dl
Total Costs
Total Yearly cost for chemical coagulation-
f1occulati on-sedimentati on
$13,236
3,716
17,402
4,261
$38,615
$ 3,862
4,248
498
$47,223
29,228
$76,451
$ 84
523
38,847
88
1,166
262
$40,970
2,364
$43,334
$45,220
311
-------
160,O'00
l
20 40 60
COD REDUCTION (%)
r 80,o oo
-70,OOO
-eopoo
- 50,000
§
f
-40,000 ~O
- 30,000
- 20,000
UJ
- 10,000
80
roo
FIGURE 81 TOTAL INVESTMENT COST AND TOTAL YEARLY COST vs COD REDUCTION
FOR ALTERNATIVE D
312
-------
Total Yearly Operating
and Maintenance
Total Yearly Cost
$ U7,i*QO
$ 57,500
An itemized cost breakdown of the filtration operation is
presented in Table 68.
The reduction benefits for Alternative E3 include a COD reduction
of 20 percent and a suspended solids reduction of 90 percent.
The incremental reduction of Alternative E3 over Alternative E2
is six percent for COD and 4.5 percent for suspended solids.
Alternative EU - The use of activated carbon will reduce the
organic fraction of this effluent, but the suspended solids level
is not reduced.
The cost of control and treatment for Alternative EU are as
follows:
Incremental Investment Cost $ 23,600
Total Investment Cost $137,000
Total Yearly Operating
and Maintenance $ 59,400
Total Yearly Cost $ 71,700
An itemized cost breakdown of the activated carbon process is
presented in Table 69.
The reduction benefits for Alternative EU include a COD reduction
of 75 percent. The incremental reduction of Alternative EU over
Alternative E3 is 19.5 percent for COD and zero for suspended
solids.
A cost efficiency curve for Alternative E is presented in Figure
82.
Alternative
- The spray evaporation process should achieve
zero discharge in the most economical fashion.
The costs of control and treatment for Alternative F are as
follows:
Incremental Investment Cost $647,700
Total Investment Cost $647,700
Total Yearly Operating
and Maintenance $ 69,800
Total Yearly Cost $128,100
313
-------
160,000-1
140,000-
120,000 -
2 100,000-
o
o
o
111
CO
UJ
GOflOO-
40,OOO-
2O,OOO-
20 40
COD REDUCTION (%)
i
60
-80,ODO
-70,000
- 60,000 -£
5
- 50.0OO
1
3.
8
O
-40,OOO>j
tc
111
-3 0,0001
H
-20,000
-10,000
80
IOO
FIGURE 82 TOTAL INVESTMENT COST AND TOTAL YEARLY COST vs COD REDUCTION
FOR ALTERNATIVE E
316
-------
An itemized cost breakdown for the evaporation pond is presented
in Table 70.
The reduction benefits for Alternative F include COD and
suspended solids reductions of 100 percent.
Related Energy Requirements of Alternative Treatment and Control
Technoloqies
As shown if Table 71, the amount of power required to operate the
various treatment alternatives for mill ponds is not
considerable, except for Alternative F. The cost of power for
the evaporation pond is more than 100 times the cost to operate
any of the other treatment alternatives.
The total direct energy costs for Alternative A through E are not
great enough to warrant their elimination from consideration.
The costs (energy) requirements for Alternative F with respect to
the benefit to the environment must be considered carefully.
Non-Water Quality Aspects of Alternative Treatment and Control
Technologies
The most significant non-water quality aspect associated with the
alternatives for treating mill pond effluents concerns the amount
and nature of the solid waste produced. Secondly, but of almost
equal significance is the aspect concerning the amount and nature
of air pollutants produced. Other important considerations
include effects on the operational efficiency of the timber
products industry and the aesthetics of the various alternative
treatment systems.
Alternative A, no treatment and control, may be considered the
base against which the other alternatives can be compared.
The types of sludge produced by Alternative B or C should be
readily disposable on land because of their highly organic nature
whereas the sludges produced by Alternative D and E are highly
inorganic and may be more detrimental to vegetation at disposal
sites. The activated carbon used and wasted in Alternative E
requires considerable amounts of energy for production and,
consequently, the use of Alternative E has an indirect energy
cost that does not appear in Table 71. The same is true for the
coagulants and flocculants used in Alternatives D and E. No
solid wastes are shown to be produced in Alternative F. Yet the
solids entering the unit must eventually be handled. It was
assumed for the purpose of cost estimates that the sludge would
be allowed to accumulate on the pond bottom with the pond being
cleaned at infrequent intervals. No costs were assigned to this.
Cleaning frequency was assumed to be greater than 20 years.
The air pollutants contributed from the various alternatives will
generally vary in proportion to the amount of processing required
for the chemicals and the energy requirements. In addition,
317
-------
TABLE 70
ITEMIZED COST SUMMARY
OF ALTERNATIVE F FOR MILL PONDS
EVAPORATION POND ONLY
INVESTMENT COSTS
ITEMS
1. Pond & Road 236,516
2. 16 Flotation pumps 268,800
505,316
3. Engineering @ 10% 50,532
4. Contingencies @ 10% 55,585
5. Land 14.66 ha @ $2470/ha 36,222
Total Investment Cost $647,655
MAINTENANCE & OPERATION
1. Power • $62,263
2. Pond Maintenance @ $1040 ha 7,574
Total Yearly Cost $128,126
318
-------
TABLE 71
YEARLY POWER USE AND COSTS
OF ALTERNATIVE TREATMENTS FOR MILL PONDS
Alternative Power Use (Kw-hrs) Yearly Cost
A 0 0
B 4,391 $85
C 4,391 $85
D 15,782 $305
E 21,260 $411
F - 2,707,087 $52,301
319
-------
Alternative F may cause measurable amounts of ammonia nitrogen to
be released to the air via air stripping,
LOG PONDS
The effluents from log ponds are considered to be derived from
natural precipitation, just as in the case for mill ponds. The
only differences between mill ponds and log ponds is that the
size of the model log pond is 20 ha (50 ac) while the model mill
pond was one hectare (three ac), and the quality of the effluent
is different. All extraneous streams are assumed to be routed
around the log pond. Five alternative treatment schemes for
treatment of the waste waters emanating from the log pond were
selected.
Cost and Reduction Benefits of Alternative Treatment and Control
Technology
Alternative A - It is estimated that 526 million 1 (139 million
gal) of wastes will emanate from the 20 hectare (50 acre) log
pond each year, or on the average of 1,441,400 Ipd (380,820 gal
per day) . The COD concentration of the waste is 52 mg/1,
yielding a daily COD waste load of 75 kilograms (165 pounds).
The suspended solids load for the same waste, based on a
concentration of 21 mg/1, is 30 kilograms per day (67 pounds per
day) .
This alternative requires reasonable process water use and
control in order to achieve volume limitations related to
precipitation and evaporation rates. The control of the
discharge of debris also may require production management
procedures, as discussed in Section VII to control the generation
of these materials. The physical layout and arrangement of the
wet storage facility and the timber processing equipment also
influence the possible discharge of debris.
Because of the variety of wet storage operations as they exist in
the field, it is not possible to present absolute cost
information. The costs of achieving the proposed limitations
range between $0 and a maximum of $9,000.
Control of the discharge of floating materials can be achieved by
such technologies as floating log booms, submerged weir discharge
structures, inverted discharge pipes, or screens.
Control of debris, diameter exceeding 2.54 cm (1.0 in), is
usually achieved by installations minimizing activity near points
of discharge or by settling action that takes place in the
collection area of a wet deck recycle system.
Alternative Bl - In Alternative Bl the flow from the log ponds is
evened out by providing an equalization basin that also functions
as an oxidation pond.
320
-------
The costs of control and treatment for Alternative B1 are as
follows:
Total Investment Costs $96,700
Total Yearly Operating
and Maintenance $ 8,700
Total Yearly Costs $17,400
An itemized cost breakdown for Alternative B1 is presented in
Table 72. The reduction benefit for Alternative B1 involves a
COD reduction of 20 percent and a suspended solids reduction of
20 percent.
Alternative g2 ~ Alternative B2 provides a second oxidation pond
in series with Alternative B1. The costs of control and
treatment for Alternative B2 are as follows:
Incremental Investment Costs $ 89,400
Total Investment Costs $186,100
Total Yearly Operating
and Maintenance $ 14,900
Total Yearly Costs $ 32,000
An itemized cost breakdown for this second oxidation pond is
presented in Table 73. The reduction benefits for Alternative B2
include a COD . reduction of 60 percent and a suspended solids
reduction of 50 percent. The incremental COD reduction is 47
percent and the incremental suspended solids reduction is 40
percent.
A cost-efficiency curve for Alternative B is presented in Figure
83.
Alternative Cl - This alternative is the same as Alternative Bl.
The costs and unit efficiencies are the same.
Alternative C2 - Chemical coagulation, flocculation, and
sedimentation comprise Alternative C2.
321
-------
TABLE 72
ITEMIZED COST SUMMARY FOR ALTERNATIVE B-l
FOR LOG PONDS
INVESTMENT COSTS
ITEMS
1. Pond 57,456
2. Wet well 2,520
3. 15m of 38cm RCP 588
4. Pump & motor installed 3,780
5. Plug valve & check valve 1,428
65,772
6. Engineering 10% 6,577
7. Conti ngenci es 10% 7,235
8. Land 6.9ha at $2470/ha 17,100
Total Investment Cost $96,684
OPERATING & MAINTENANCE
1. Power 941
2. Pond $1040/ha/yr 6,174
3. Pumping Station Maintenance 1,579
Total Cost 8,694
Total yearly cost for Equalization - Oxidation Pond $17,396
322
-------
TABLE 73
ITEMIZED COST SUMMARY FOR ALTERNATIVE B-2
FOR LOG PONDS
INVESTMENT COSTS
ITEMS
1. Pond 57,456
2. 15m of 38cm RCP 588
3. 25cm plug & 25cm check valve 1,428
4. 9m of 25cm C.I. pipe 252
5. Engineering 10%
6. Contingencies 10%
7. Land 6.9ha at $2470/ha
Incremental cost
Cost of alternative Bl 96,684
Total Cost . 186,050
OPERATING AND MAINTENANCE
1. Pond Maintenance (6.0ha $1040/ha) 6,174
incremental cost 6,174
Cost of alternative B-l 8,694
Total Cost 14,868
Total yearly cost for second oxidation pond $14,582.84
323
-------
200,000 -
175,000 -
150,000 -
135,000 -
o
100,000
o
o
I- 75,000 -
CO
Id
50,000 -
- 30,0,00
-25,000-'
-20,000
-15,000
-10,000
- 5,000
2O 40 60 80
COD REDUCTION (%)
100
FIGUBE 83 TOTAL INVESTMENT COST AND TOTAL YEARLY COST vs COD SEDUCTION FOR
ALTERNATIVE B
321,
-------
The costs of control and treatment for Alternative C2 are as
follows:
Incremental Investment Costs $122,300
Total Investment Costs $218,900
Total Yearly Operating
and Maintenance $ 86,058
Total Yearly Costs $105,800
An itemized cost breakdown for Alternative C2 is presented in
Table 74. The reduction benefits for Alternative C2 include a
COD reduction of 60 percent and a suspended solids reduction of
90 percent. The incremental COD reduction is 47 percent and the
incremental suspended solids reduction is 72 percent. A cost-
efficiency curve for Alternative C is presented in Figure 84.
costs and unit efficiencies are the same.
Alternative D2 - This alternative is the same as Alternative C2.
The costs and unit efficiencies are the same.
Alternative D3 - This alternative consists of a gravity sand
filter for suspended solids removal which will also affect some
COD removal.
The costs of control and treatment for Alternative D3 are as
follows:
Incremental Investment Costs $152,500
Total Investment Costs $371,400
Total Yearly Operating
and Maintenance $104,900
Total Yearly Costs $138,400
An itemized cost breakdown for the filtration system is presented
in Table 75. The reduction benefits for Alternative D3 include a
COD reduction of 20 percent and a suspended solids reduction of
90 percent. The incremental COD reduction is six percent and the
incremental suspended solids reduction is seven percent.
Alternative D4 - The final process considered in Alternative D is
the use of activated carbon for soluble COD removal.
The costs of control and treatment for Alternative D4 are as
follows:
Incremental Investment Costs $408f100
Total Investment Costs $779,600
325
-------
TABLE 74
ITEMIZED COST SUMMARY FOR ALTERNATIVE C-2
FOR LOG PONDS
INVESTMENT COSTS
ITEMS
1. Mixing & chemical addition $13,566
2. Flocculator 20,076
3. Sedimentation Equipment 44,940
4. Building 12,818
5. Sludge Disposal 8,503
99,903
6. Engineering 10% 9,990
7. Contingencies 10% 10,989
8. Land 0.55ha at $2470/ha 1,370
Incremental Cost $122,252
Cost of alternative C-l 96,684
Total investment cost $218,936
OPERATION & MAINTENANCE
1. Power 618
2. Maintenance 5,028
3. Chemicals 29,005
4. Labor 36,288
5. Sludge Disposal 6,425
Incremental Cost 77,364
Cost of alternative C-l 8,694
Total costs 86,058
Total yearly costs of chemical coagulation - flocculation -
sedimentati on $88,367
326
-------
200,000-
z
co-
rn 150,000-
o
o
^ lOOpOO
sopoc
-125,000
g
-100,000 J
o
-7SPOO CO
O
-60POO >
_J
-26POO.
20
40 60 80
COO REDUCTION (%)
KX)
FIGURE 84 TOTAL INVESTMENT COST AND TOTAL YEARLY COST vs COD
REDUCTION FOR ALTERNATIVE C
327
-------
TABLE 75
ITEMIZED COST SUMMARY FOR ALTERNATIVE D-3
FOR LOG PONDS
INVESTMENT COSTS
ITEMS
1. Filter chambers (2) 56,330
2. Sand (78cm) 8,089
3. Gravel (46cm) 4,855
4. Piping & fittings & valves 9,265
5. Backwash Pump 12,600
6. Building 31,190
7. Sludge disposal equipment 1,699
8. Engineering 10%
9. Contingencies 10%
10. Land 0.98ha at $2470/ha
Incremental cost $152,504
Costs of alternative Dl & D2 218,936
Total cost 371,440
OPERATING & MAINTENANCE COSTS
1. Power 70
2. Maintenance 5,957
3. Sludge disposal costs 12,840
Incremental cost 18,867
Costs of alternative Dl & D2 86,058
Total cost 104,925
Total yearly costs of gravity sand filtration $32,592
328
-------
Total Yearly Operating
and Maintenance $173,800
Total Yearly Costs $2UU,100
An itemized cost breakdown for the activated carbon system is
presented in Table 76. The reduction benefits for Alternative D4
include a COD reduction of 75 percent and no suspended solids
reduction. The incremental COD reduction is 20 percent and the
incremental suspended solids reduction is zero.
A cost-efficiency curve for Alternative D is presented in Figure
85.
Alternative E - Alternative E consists of the placement of spray
evaporators on the existing log pond and the enlargement of the
berm.
The costs of control and treatment for Alternative E are as
follows:
Total Investment Costs $1,074,300
Total Yearly Operating
and Maintenance $ 166,000
Total Yearly Costs $ 262,700
An itemized cost breakdown for Alternative E is presented in
Table 77. The reduction benefits for this alternative include
100 percent COD reduction and 100 percent suspended solids
reduction. The incremental reductions are the same.
Related Energy Requirements of Alternative Treatment and Control
Technologies
As shown in Table 78, the amount of power required to operate the
various alternatives for log ponds is not considerable except for
Alternative E. As in the consideration of mill ponds, the power
costs to spray evaporate the excess water from the log pond are
greater than any of the other treatment techniques. However,
because of the modified evaporation-log pond, the cost is not in
proportion to the flow rate. The cost of heat to regenerate the
activated carbon in Alternative D has been converted to kilowatt
hours and is shown in Table 78.
There is considerable discussion in the industry concerning the
possibility of removing logs from the water, including log ponds,
and utilizing land decking entirely. One study showed that three
dollars per two cu m (about 1,000 bd ft) could be saved when dry
decking of logs was used in place of a log pond. This savings
was determined on the basis of saved manpower. In another study
at a different mill site, more factors were considered. The
329
-------
TABLE 76
ITEMIZED COST SUMMARY FOR ALTERNATIVE D-4
FOR LOG PONDS
INVESTMENT COSTS
ITEMS
cum
1. 3800 day pump w/15 hp motor 2,100
2. Contact columns & piping 63,000
& carbon handling equip.
i
3. Initial carbon charge 22,260
4. Regeneration equipment 213,360
5. Building 36.490
337,210
6. Engineering 10% 33,721
7. Contingencies 10% 37,093
8. Land 0.04ha @ $2470/ha 100
Incremental cost $408,124
Cost of alternative Dl,D2a & D3 371.440
Total costs 779,564
OPERATING & MAINTENANCE (6 months operation)
1. Power 932
2. Carbon handling equipment 13,440
3. Carbon regeneration 49,981
Fuel 1,050
Power 630
4. Building 2,890
Incremental cost 68,923
Cost of alternative D1,D2, & D3 104,925
Total Cost 173,848
Total yearly cost for activated carbon 105,654
330
-------
800,000-1
700,000 -
^ 600,000
o
XI
I-
eo
o
° 500,000
K
Z
UJ
z
CO
UJ 400,000
300,000-
200,000 -
IOO,OOO -
I-
250,000 g
O
5
CCL
UJ
200,000 >•
I
-150,000
- 100,000
- 50,000
20
40 60 80
COD REDUCTION (%)
100
FIGURE 85 TOTAL INVESTMENT COST AND TOTAL YEARLY COST vs COD
REDUCTION FOR ALTERNATIVE D
331
-------
TABLE 77
ITEMIZED SUMMARY FOR ALTERNATIVE E
FOR LOG PONDS
INVESTMENT COSTS
ITEMS
1. Spray evaporators 42 @ $16,800 each 705,600
2. Alterations of log pond 177,116
3. Engineer!ng 10% 88,272
4. Contingencies 10% 97,099
5. Land 2.5ha @ $2470/ha 6,170
Total Costs 1,074,257
OPERATING & MAINTENANCE
1. Additional Maintenance cost 2,591
2. Power 163,440
Total Costs 166,031
Total Yearly costs for spray evaporators on the log pond $262,714
332
-------
TABLE 78
YEARLY POWER USE AND COSTS FOR
ALTERNATIVE TREATMENT FOR LOG POND
Alternative Power Use (Kw-hrs) Yearly Costs (dollars)
A 0 0
B 72,511 1,400
C 80,086 1,600
D * 211,100 4,100
E 8,459,652 163,440
* Fuel for activated carbon recharge = 54,326 Kw-hrs = $1100
333
-------
energy required to operate a dry decking operation 0.5 miles from
the processing plant was compared to the energy required to
generate water storage of the same logs at the mill site.
Electrical costs were about the same, but it was estimated that
the amount of fuel required to operate the dry deck would be
300,000 1 (80,000 gal per year) for the dry deck and U0,000 1 per
year (11,000 gal per year) in the water storage.
The comparison of energy requirements for land decking as opposed
to water storage will depend on the specific requirements at each
mill location. However, it was observed in the current study
that sorting and storing of logs in water generally requires less
energy and effort than the same operation on land. The above
cited figures tend to support this observation, yet the long haul
distance to the land deck in the above example makes the amount
of energy required for land decking larger than would normally be
expected.
Non-Water Quality Aspects of Alternative Treatment and Control
Technologies
The significant non-water quality aspects associated with log
ponds are the same as those for mill ponds, i.e., solid wastes,
air pollutants, operational efficiency, and aesthetics. In
general, these aspects are similar to those for mill ponds, but
the quantities are significantly greater because of the larger
pond size, higher flow rates, and different waste
characteristics.
Alternative D for log ponds includes on-site regeneration of
activated carbon, so the amount of activated carbon disposed of
as a solid waste is less, but the amount of power required for
regeneration of the carbon is higher. The aesthetics of the
large treatment units may be negative and the cost to the
industry is more than for treatment of the mill pond effluent.
The decision of whether to remove the logs from the water
entirely can also depend on non-water quality parameters. These
were studied by Schaumberg and the estimates of the quantities of
these solid and air pollutants are shown in Table 79. The
difference in the amounts of these materials produced for the two
log storage techniques is considerable.
WET DECKING
The effluents from wet decking operations are similar in
character to those of mill and log ponds. Because the water used
on the wet decks was assumed to be recycled, the only time that
an effluent occurs is when the runoff volume from precipitation
exceeds the storage capacity of the recycle pond. With these
restrictions, the wet deck effluent has the same flow character
and volumes as the mill and log ponds. The precipitation on the
wet deck is highly variable with the area of the country and the
amount of flow from the wet deck is directly proportional to the
area of the wet deck and recycle pond. Because the typical wet
331*
-------
TABLE 79
NON-WATER. QUALITY WASTES GENERATED FOR
LAND DECKING AND WATER STORAGE
Pol1utant
Solid Wastes*
Land Deck Emission
(kilograms/year)
400
Water Storage
Emissions
(kilograms/year)
68,000
Air Pollutants
Particulates 450
Oxides of sulfur 1000
' Carbon Monoxide 9000
Hydrocarbons 1400
Oxides of Nitrogen 13500
50
140
1,300
180
1,800
*Bark @ 240 kg/cu m
335
-------
deck may have an area from one half hectare to 50 ha (one acre to
120 ac) and it may be located in almost every location in the
country with the exception of the arid Southwest, it is not
possible to decide on typical flows from the wet deck. For this
reason, two flows were chosen to represent one small wet deck and
one large wet deck. These flows are three and U4 I/sec (50 and
69** gpm) for six months of the year. These are the same flows as
chosen for mill and log ponds, respectively.
Because the treatment schemes for the treatment of waste waters
from wet decks are virtually identical to those chosen for mill
and log ponds, the designs and costs for those units are
applicable to wet decks. All costs for wet deck treatment units
are the same as those for mill and log ponds previously
discussed. A summary of costs for the two flows is presented in
Table 80.
Related Energy Requirements of Alternative Treatment and Control
Technologies
The amount of power required to operate the various alternative
treatment units are the same as those discussed for mill ponds
and log ponds. Since wet decking is a type of land decking, the
energy requirements discussed in land decking and water storage
are also applicable to wet decking. The power or energy required
to sort and move the logs on land is considerably higher than the
energy required to sort and move the logs in water. The energy
required to sprinkle the log deck is small compared to the energy
required to move and sort the logs.
The non-water quality aspect of wet decking are the same as those
for mill ponds and log ponds. The wet decks themselves may have
different aesthetic value than water storage, but pollutant loads
to the air and land from the treatment alternatives are the same
as for mill ponds or log ponds.
LOG HASHING
The log washing operation developed in Section V possessed the
following characteristics:
1. The log wash operates 16 hours per day, 250 days per
year.
2. Existing facilities are the log washer itself including
the pump and appropriate piping.
3. No treatment is presently given the log washer effluent.
H. Volumetric rate of flow is 25 I/sec (400 gpm).
5. Volume of logs washed per day equals 280 cu m (9,887 cu
ft) .
336
-------
TABLE 80
COSTS SUMMARY FOR WET DECKING
CO
GJ
Alternatives
A (no treatment
B,C1,D1,E1 (recycle-equalization
sedimentation)
C2 (oxidation pond #2)
D2Ji2 (chemical coagulation
flocculation)
E3 (filtration)
E4 (activated carbon)
F (evaporation pond)
Incremental Investment
3
Cost
I/sec 44 I/sec
Total
Investment
Cost
Total
Yearly
Op.
Total Yrly
Costs
Cost
3 I/sec. 44
0
ion
29,
18,
47,
36,
23,
647,
0
200 96,700
300 89,400
200 122,300
900 152,500
600 408,100
700
0
29,
47,
76,
113,
137,
647,
200 96
500 186
500 218
400 371
000 779
700
I/sec
0
,700
,000
,900
,500
,600
3 I/sec
0
2,400
3,200
43,400
47,400
59,400
69,800
44
8
14
86
104
173
I/sec
0
,700
,900
,058
,900
,800
3
5
7
50
57
71
128
I/sec
0
,000
,400
,200
,500
,700
,100
44/sec
17
32
105
138
144
0
,400
,000
,800
,400
,100
- .
-------
The assumptions made for the development of costs for control and
treatment technologies for the treatment alternatives for log
washing include the following:
1. Adequate land is available on site for treatment
facilities.
2. No extensive changes are required in the mill feed to
allow treatment of the effluent from the log washing
operation.
Alternative A - This alternative consists of no control or
treatment. It requires no costs and results in no reduction
benefits. The total kilograms of COD per day resulting from the
application of Alternative A are "110 (310 Ibs) while the
suspended solids load discharged would be 106 kilograms per day
(234 pounds per day).
Alternative B - This alternative consists of total recycle of the
log wash effluent. Total recycle can be achieved by
sedimentation of settleable solids and screening of the suspended
solids. Sludge ponds to thicken settled material are also
required. A summary of the costs of treatment and control
follow. Itemized costs are given in Table 81.
Costs of Treatment and Control
Total Investment Costs $27,600
Total Yearly Operating
and Maintenance $14,700
Total Yearly Costs $17,200
Reduction benefits: Reduction benefits of 100 percent of all
pollutants are achieved.
Related Energy Requirements of Alternative Treatment and control
Technologies
No information is available regarding energy requirements for log
washing. However, the total energy requirements for a sawmill
producing 280 cu m per day (10,000 cu ft per day) are
approximately 28,000 kw hrs/ day of energy.
At a cost of 2.3 cents per kilowatt hour, energy cost for a 280
cu meter (10,000 cu ft) per day mill equals approximately
$161,000 dollars per year. The associated yearly energy costs
for the recommended control and treatment alternatives are
estimated to be:
338
-------
TABLE 81
COSTS OF CONTROL AND TREATMENT, ALTERNATIVE B
FOR LOG WASHING OPERATIONS
INVESTMENT COSTS ESTIMATE
Item
1. Screen, horizontal conveyor type, complete
2. Settling tank 200 cu m (7000 ft3) complete
3. Screen, vibrating, complete
4. Sludge pump
5. Sludge Pond
6. Engineering
7. Contingencies
Total
OPERATING COSTS ESTIMATE
Item
1. Operation and Maintenance
2. Electricity
Total
Costs
$3,108
10,920
3,108
840
4,872
2,285
2.513
$27,646
Costs
$13,780
899
$14,679
333
-------
Alternatives Cost
A 0
B $899
Non-"Water Quality Aspects
Non-water quality aspects can be expected to be minimal. The
disposal of settled materials should be accomplished by landfill.
SAWMILLS AND PLANING MILLS
For the purposes of this report the sawmill and planing mill
segment of the timber products processing industry has been
defined to exclude the following items or operations:
1. Piles of fractionalized wood.
2. Log storage and handling.
3. Debarking.
U. Log washing.
5. Steam and power generating facilities.
6. Finishing operations.
The above operations including control and treatment technology
and associated costs are discussed elsewhere in this document.
Cost and Reduction Benefits of Alternative Treatment and control
Technologies
The specific assumptions utilized in the development of costs of
control and treatment for sawmills and planing mills are the
following:
1. Water used for cooling saws and lubricating belts is
minimized.
2. No water is used in cleanup of floors.
3. Equipment leakage is controlled.
4. Cooling water for condensers, turbines and pumps is
removed from the point of use by closed pipes as is
boiler blowdown and ion exchange media backwash.
5. Lumber finishing compounds such as coatings, stains or
water proofing compounds are recycled as is washwater
developed during cleaning of the applicators.
31*0
-------
6. Preservative dip tanks are covered to prevent rain from
entering them; lumber is allowed to drip-dry prior to
stacking, or drippage is collected and returned to the
dip tank.
7. Steam condensate is returned from drying kilns to the
boiler.
The above assumptions are considered to be valid in that in a
well managed mill these are generally considered standard
practice. On the basis of these assumptions, no further control
and treatment is required to acheive a zero discharge limitation
and no costs of control and treatment are thereby incurred.
FINISHING
Two models were selected in section V as being representative of
fabricating operations. Model 1 utilizes one spreader, one
finger jointer and one mixing vessel, all of which require daily
cleanup using a total of 750 1 (200 gal) of water. Model 2
consists of five double roller spreaders, three finger jointers,
one catalyst mixer, and two resin mixing tanks. The resulting
daily waste water production from Model 2 is 5700 1 (1500 gal).
Both models are assumed to operate seven days per week, 52 weeks
per year.
Cost and Reduction Benefits of Alternative Treatment and Control
Technologies ~ ~"
In addition to the assumptions listed at the beginning of this
section, the following assumptions are made regarding costs of
the various alternatives:
1. No control or treatment presently exists.
2. For alternatives requiring land, it is assumed that it
is available at $2500 per hectare.
3. Discharge to a municipal sewer system entails no hookup
charges and a maximum monthly charge of $25.
Alternative A - This alternative consists of no waste water
control of treatment. Therefore, there are no costs of treatment
and no reduction benefits.
Alternative B - This alternative consists of screening followed
by discharge to an evaporation pond. Evaporation is accomplished
by spray evaporators where precipitation exceeds evaporation plus
waterflow. A summary of the costs and reduction benefits
associated with this alternative is presented below. These costs
represent average costs for all five regions, rounded to the
nearest hundred dollars. A detailed breakdown of investment and
operating costs is given in Table 82.
Model 1
-------
costs of Treatment, and Control
Total Investment Costs $27,000
Total Yearly Operating
and Maintenance $ 1,900
Total Yearly Costs $ ft,200
Reduction Benefits: One hundred percent reduction is achieved.
Model 2
Costs of Treatment and Control
Total Investment Costs $47,800
Total Yearly Operating
and Maintenance $ 4,600
Total Yearly Cost $ 8,900
Reduction benefits: One hundred percent reduction of pollutant
discharge is achieved.
Alternative C - This alternative consists of screening followed
by discharge to a holding tank. Incineration is then
accomplished by spraying the glue wastes on the hog fuel prior to
burning. It is assumed that a hogged fuel furnace is presently
on site. A summary of costs of control and treatment and
reduction benefits are presented below. Detailed cost
information is presented in Table 83.
Model 1
Costs of Treatment and Control
Total Investment Costs $9,000
Total Yearly Operating
and Maintenance $3,400
Total Yearly Costs $4,200
Model 2
Costs of Treatment and Control
Total Investment Costs $17,200
Total Yearly Operating
and Maintenance $ 4,300
-------
TABLE 83
-COSTS OF CONTROL AND TREATMENT
FOR ALTERNATIVE C FOR FABRICATION OPERATIONS
Model 1
Investment Cost Estimate
Item Cost
1. Screens $2,300
2. Screen Building, Foundation 4,682
3. Pump 210
4. Sump 213
5. Engineering 741
6. Contingencies 815
TOTAL $8,961
Operating Cost Estimate
Item Cost
1. Electricity
2. Operation & Maintenance
TOTAi $3,394
Model 2
Investment Cost Estimate
Item Cost
1. Screen $2,300
2. Screen Building, Foundation 4,682
3. Pump 210
4. Sump 6,982
5. Engineering 19417
-------
TABLE 83 (Cont.)
Model 2 Cont.
Investment Cost Estimate
Item
6. Contingencies
Operating Cost Estimate
Item
1. Electricity
2. Maintenance & Operation
TOTAL
TOTAL
Cost
$1.559
$17,150
Cost
$ 30
4,266
$4,296
-------
Total Yearly Cost $ 5,800
Reduction Benefits: One hundred percent reduction of pollutant
discharge is accomplished.
Alternative D - This alternative consists of screening to remove
large glue solids followed by landspreading. A summary of the
costs of control and treatment and the reduction benefits is
presented below. A detailed description of investment and
operating costs is presented in Table 84.
Model 1
Costs of Treatment and control
Total Investment Costs $9,900
Total Yearly Operating
and Maintenance $1,800
Total Yearly Cost $2,700
Reduction Benefits: Reduction benefits may be assumed to be 100
percent.
Model 2
Costs of Treatment and control
Total Investment Cost $12,200
Total Yearly Operating
and Maintenance $11,100
Total Yearly Cost $12,200
Reduction Benefits: One hundred percent reduction of pollutant
discharge is achieved.
Alternative E - This alternative consists of screening followed
by discharge to a holding tank and recycle of the settled glue
waste water for reuse in cleaning. Piping is provided to provide
makeup water, bleedoff to incineration and use of a portion of
the waste water for glue mixing. It is assumed that makeup water
is available from existing water distribution system and that a
hogged fuel burner is presently on site. A summary of costs and
reduction benefits is presented below. A detailed breakdown of
investment and operating costs is presented in Table 85.
Model 1
Costs of Treatment and control
Total Investment Costs $10,900
31*7
-------
TABLE 84
COSTS OF CONTROL AND TREATMENT
FOR ALTERNATIVE D FOR FABRICATION OPERATIONS
Model 1
Investment Cost Estimate
Item
1. Screen
2. Screen Building, Foundation
3. Holding Tank & Foundation
4. Pump
5. Engineering
6. Contingencies
Operating Cost Estimate
Item
1. Electricity
2. Operation & Maintenance
Model 2
Investment Cost Estimate
Item
1. Screen
2. Screen Building, Foundation
3. Holding Tank & Foundation
4. Pump
5. Engineering
6. Contingencies
TOTAL
TOTAL
Cost
$2,300
4,682
945
250
818
900
$9,895
Cost
$ 20
1,787
$1,807
Cost
$2,300
4,682
2,835
250
1,007
1,107
TOTAL $12,181
-------
TABLE 84 (Cent.)
Model 2 Cont.
Operating Cost Estimate
Item
1. Electricity
2. Operation and Maintenance
TOTAL
Cost
$ 30
11,073
$11,103
-------
TABLE 85
COSTS OF CONTROL AND TREATMENT
FOR ALTERNATIVE E FOR FABRICATION OPERATIONS
Model 1
Investment Cost Estimate
Item
1. Screens
2. Screen Building, Foundation
3. Holding Tank, Foundation
4. Sump
5. Sump Pump
6. Pump, Piping & Controls for Incineration
7. Piping & Valves
8. Engineering
9. Contingencies
Operating Cost Estimate
Item
1. Electricity
2. Operation & Maintenance
Model 2
Investment Cost Estimate
Item
1. Screen
2. Screen Building, Foundation
TOTAL
TOTAL
Cost
$2,300
4,682
735
153
420
420
336
905
995
$10,946
i
Cost
$ 12
313
$ 325
Cost
$2,300
4,682
350
-------
TABLE 85 (Cont.)
Model 2 Cont.
Item Cost
3. Holding Tank, Foundation $1,995
4. Sump 370
5. Sump Pump . 420
6. Pump, Piping Controls for Incineration 420
7. Piping & Valves 336
8. Engineering 1,052
9. Contingencies 1,158
TOTAL $12,733
Operating Cost Estimate
Item Cost
1. Electricity $ 12
2. Operating & Maintenance 411
TOTAL $ 423
351
-------
Total Yearly Operating
and Maintenance $ 300
Total Yearly Cost $ 1,300
Reduction benefits: 100 percent reduction is achieved,
Model 2
Costs of Treatment and Control
Total Investment Costs $12,700
Total Yearly Operating
and Maintenance $ i»00
Total Yearly Costs $ 1,600
Reduction benefits: 100 percent reduction is achieved.
Alternative F - This alternative consists of discharge to a
municipal sewer. For the purpose of determining costs of
municipal treatment, it is assumed that there are no hookup
charges and that a minimum monthly rate of twenty-five dollars is
charged for both model systems.
Costs of Treatment and Control
Total Yearly Operating
and Maintenance $300
Total Yearly Costs $300
Reduction benefits: One hundred percent reduction is achieved.
Cost Summary for Alteruatives - A summary of costs for the
treatment alternatives is presented in Table 86.
Related Energy Requirements of Alternative Treatment and Control
Technologies
The industries represented by this subcategory are extremely
diverse in terms of product produced and energy consumed.
Therefore, no information available which is representative of
energy requirements for fabricating operations.
The following costs are the anticipated annual energy costs the
the alternative treatment and control technologies:
352
-------
TABLE 86 SUMMARY OF ALTERNATIVE COSTS
FOR FABRICATION OPERATIONS
*Summary of Alternative Costs, Model 1
Alternative
A
B
C
D
E
F
Alternative
A
B
C
D
E
F
Percent
Reduction
0
100
. 100
100
100
100
*Summary
Reduction
0
100
100
100
100
100
Investment
Costs
0
$27,000
$ 9,000
$ 9,900
$10,900
0
of Alternative
Costs
0
$47,800
$17,200
$12,200
$12,700
0
Total Yearly
Operating
Costs
0
$1,820
$3,400
$1 ,800
$ .300
$ 300
Costs., -Model 2
Total Yearly
Costs
0
$ 4,600
$ 4,300
$11,100
$ 400
$ , 300
Total Yearly
Operating
Costs
0
$4,200
$4,200
$2,700
$1,300
$ 300
Total Yearly
Costs
0
$ 8,900
$ 5,800
$12,200
$ 1,600
$ 300
*Average costs for all five regions
353
-------
Alternative
A
B
C
D
E
F
Non-Water Quality Aspects
The non-water quality aspects of the various alternatives are
anticipated to be negligible. However, disposal of glue wastes
by landspreading must be controlled carefully to avoid
contamination of ground water and surface water. Incineration
should be monitored to determine any impact on air quality.
Alternative E, wash water reuse, will provide the least impact
potential for both water and non-water quality aspects and is
also the least energy consuming treatment technology.
INSULATION BOARD SUBCATEGORIES
The costs estimates contained in this document are based on
actual preliminary cost estimates for waste treatment systems
defined in Section VII for a model £lant defined in Section V
(Water Use and Waste Characterization) of the insulation board
industry. Land costs were assumed to be $2000 an acre based on
the assumption that insulation board plants are located on the
outskirts of medium size towns. The design criteria for the
various treatment technologies presented below are essentially
the same for all subcategories. Therefore, unless otherwise
noted the description of the treatment alternatives can be
considered applicable to all subcategories.
The insulation board industry was subcategorized into two
subcategories as previously discussed. The raw waste water
discharge for a plant of each subcategory appear below:
Flow Production BOD TSS
Subcategorv 1/kkcr kkg/Day kg/kkcr kg/kkg
I 5U,250 270 12.5 10
II 54,250 270 37.5 10
It should be noted that these flows and loads occur after primary
clarification since the plants are all assumed to have primary
clarifiers. Also, there is assumed to be 2700 kg/day (6,000
Ibs/day) (dry weight) at 3 percent consistency 10 kg/kkg (20
Ibs/ton) of sludge from the existing clarifier, which is disposed
35k
-------
of by an existing system. The loads and flows given do not
include cooling water, boiler blowdown, roof runoff, yard runoff,
fire fighting, or waters from raw material handling and storage
operations.
COST AND SEDUCTION OF ALTERNATIVE
TECHNOLOGIES
TREVTMENT AND CONTROL
Alternative A - This alternative consists of no treatment of the
waste water discharged from the model plant's primary clarifier.
There is no cost involved and no reduction benefits.
Alternative B - This alternative consists of aerated lagoons of
19 day detention time followed by a settling pond with 24 hour
detention time added to Alternative A. This alternative provides
for an 85 percent BOD reduction in the waste water based on
accepted design criteria and a conservative estimate of reaction
rates. The sludge from the settling pond will be removed once a
year by dredging and trucking to landfill or by land spreading.
A detailed cost summary is presented in Table 87.
The costs involved for the alternative are as follows:
Subcategorv I
Initial Investment $380,000
3U,500
Yearly Operation
and Maintenance
Total Yearly Cost
$ 87,300
Subcategory II
$380,000
91,300
$155,100
This system provides for an 85 percent reduction of BOD
percent reduction of suspended solids.
and 70
Alternative cl - This alternative consists of an activated sludge
system with sludge handling facilities. Waste sludge is pumped
to a thickener with a loading rate of U100 Ipd per sq m (100
gpd/sq ft). The underflow at a consistency of 5 percent is
dewatered by a coil drum vacuum filter prior to which filter aids
are added. The dewatered sludge then disposed of in a landfill.
The activated sludge system was designed using the following
criteria: mixed liquor suspended solids is equal to 2,500 mg/1,
loading rate for the aeration tank is equal to 0.2 kg of BOD per
kg of MLSS, loading rate for the secondary clarifier is equal to
1900 Ipd. The aeration requirements were calculated using
standard design parameters and nutrient addition and pH
adjustment were provided. A detailed cost summary is presented
in Table 88.
Total Investment
Subcategorv I Subcategorv II
$954,100 $1,160,800
355
-------
TABLE 87
ITEMIZED COST SUMMARY
FOR ALTERNATIVE B FOR INSULATION BOARD
INITIAL INVESTMENT COSTS
CO
01
en
ITEM
Subcategory I
$380,032
35,879
2,100
50,400
Land 4.0 hectares(9.8 acres) 19,600
Engineering and Contingencies 98,366
$586,377
Aerated Lagoon
Settling Pond
Pump
Aerators
COST
Operation and Maintenance
Power
Subcategory II
$380,032
35,879
2,100
117,600-151,200
19,600
119,534
$667,689-708,345
OPERATION AND MAINTENANCE
$ 4,221 $4,221
30,300 68,176-87,114
$34,521 $72,397
-------
Yearly Operating 216,700 287,800
and Maintenance
Total Yearly Cost $302,600 $392,300
A 90% reduction in BOD and 70* reduction of suspended solids is
achieved by this system.
Alternative C2 - This alternative consists of an addition of an
aerated lagoon with a quiescent settling area to Alternative C1.
The addition of an aerated lagoon, based on design parameters
presented in Alternative B, will have an eight day detention
time. The quiescent area will be dredged once a year and solids
trucked to landfill. A detailed cost summary is presented in
Table 89. The costs for this alternative are as follows:
Subcategory I Subcatecrorv II
Incremental Investment $ 236,500 $ 236,500
Total Investment 1,190,600 1,397,300
Yearly Operation 235,900 306,900
and Maintenance
Total Yearly Cost $ 343,100 $ 432,700
An incremental reduction of BOD of 70X and no incremental
suspended solid reduction is achieved by this system. An overall
reduction of BOD of 97% and SS of 70% is realized. Cost
efficiency curves for Alternative C are shown in Figures 86, 87,
88.
Alternative Dl - This alternative consists of an activated sludge
system and sludge handling facilities as described in Alternative
C1. A detailed cost summary is presented in Table 88.
Alternative D2 - This alternative provides a suspended solids
removal system for secondary effluent of Alternative D1 so that a
portion of this water can be recycled back to the process.
Suspended solids are removed by use of a multi-media filter with
backwashing facilities. The filter is designed for 100 percent
of the flow with a surface loading rate of 163 I/ sq m/min (4.0
gal/sq ft/min). Backwashing is accomplished with filtered water.
Although this system is designed for recirculation of 100 percent
of the effluent, complete recycle may not be feasible.
Therefore, for this system only 70 percent of the secondary
clarifier discharge will be recycled back to the plant. A
detailed cost summary is presented in Table 90. The costs
involved for this alternative are as follows:
357
-------
TABLE 88 ITEMIZED COST SUMMARY
FOR ALTERNATIVES C-l, AND D-l FOR INSULATION BOARD
INITIAL INVESTMENT COSTS
CO
01
co
ITEM
Activated Sludge Subcategory I
Nutrient & pH Control Equip. $21,420
Lagoon (w/Liner) 53,088
Secondary Clarifier
(w/skimmer) 111,300
Aerators 50,400
Pipes, Valves & Fittings 63,000
Electrical (Miscellaneous) 63,000
Instrumentation 42,000
Sub-Total - Activated
Sludge $404,208
Sludge Disposal Facilities
Thickener (w/skimmer) $70,980
Polymer Feed Equip. 10,920
Coil Filters 223,440
Belt Conveyor 36,960
Subcategory II
$21,420
101,004-120,597
$519,324-572,517
$70,980
10,920
223,440
36,960
-------
TABLE 88 (Cont.)
Item
Building
Subcategoty I
37,800
Sub-Total - Sludge Disposal $380,100
Subcategory II
37.800
$380,100
CO
en
00
Engineering & Contingencies 164,705
Land 5,100 (1.0 ha)
TOTAL INVESTMENT $954,113
188,879 - 200,050
7,280 - 8,160 (1.7 ha)
$1,095,583 - 1,160,827
-------
TABLE 89
CO
en
o
ITEMIZED COST SUMMARY
FOR ALTERNATIVE C-2 FOR INSULATION BOARD
Total Investment Costs
ITEM
Aerated Lagoon
Aerators
Land {2.0 ha.)
Engineering and Contingent
Incremental Investment
Cost C-l
TOTAL INVESTMENT
Operation and Maintenance
Power
Incremental Investment
Cost C-l
TOTAL OPERATION AND
MAIMEENSNCE
COST
Stfbcafeaoow -i
$147,000
40,320
9,800
ies 39,337
$236,457
954,113
$1,190,570
Operation and Maintenance
Subcategory II
$147,000
40,320
9,800
39,337
236,457
1,095,583-1,160
$1,332,040-1,397
,827
,284
$4,013
15,150
$4,013
15,150
19,163
216.690
19,163
264,068-287,752
$235,853
$283,231-306,915
-------
TABLE 90
ITEMIZED COST SUMMARY FOR
ALTERNATIVE B-2 FOR INSULATION BOARD
CO
CO
ITEM
Mixed Media Pressure Filter
(w/media)
Filtered Water Storage
Tank
Back Wash Pump
Pipes Valves Fittings
Electrical (misc.)
Instrumentation
Control Building
Addition
Land (.012 Hec.)
Incremental Investment
COST D-l
TOTAL INVESTMENT
Operation and Maintenance
Media Replacement
COST
Subcategory I
k
58,800
6,720
10,800
8,400
1,680
8,400
10,800
60
105,660
954,113
1,059,773
Operation and Maintenance
3,108
1,680
Subcategory II
58,800
6,720
10,800
8,400
1,680
8,400
10,800
60
105,660
1,095,583
1,201,243
3,108
1,680
-------
TABLE 90 (Cont.)
CO
CD
Item
Power
Incremental Investment
Cost D-l
TOTAL OPERATIONS &
MAINTENANCE
Cost
Subcategocy I
222,822
Subcategory
1,344
6,132
216,690
1,344
6,132
264,068
270,200
-------
INVESTMENT COST_ (dollars)
Co
CD
GO
Kj
O rt
o-
O
1
fs>
Ul
p
"b
o
o
.
W
8
o
o
o
51
o
"o
o
o
o
8
"o
o
o
M
Ul
p
O
o
o
TOTAL YEARLY COST (dollars/year)
-------
1,500,000 -
4O 6O
BOD REDUCTION (%)
80
100
FIGURE 87 TOTAL INVESTMENT COST AND TOTAL YEARLY COST vs BOD
REDUCTION FOR. ALTERNATIVE C-SUBCATEGORY II OF THE
INSULATION BOARD INDUSTRY
36!*
-------
INVESTMENT COST (dollars)
CD
tn
Ul
o
8
o
en
o
P
o
o
o
p
O
o
o
N
U
€
8
at
O
O
"o
8
fs>
O
s
o
3)
m
o
Z m
o
o
o
p
"o
o
o
ro
o
p
"o
o
o
o
p
o
o
o
o
o
"o
o
o
en
o
o
"o
o
o
TOTAL YEARLY COST (doltars/years)
-------
Subcategorv I Subcateaorv II
Incremental Investment $ 105,660 $ 105,660
Total Investment 1,059,800 1,266,500
Yearly Operation 222,800 293,900
and Maintenance
Total Yearly Cost $ 318,200 $ 407,900
An incremental reduction is achieved by this system resulting in
a 97% overall reduction of BOD and a 91% reduction of suspended
solids overall.
Cost efficiency curves for Alternative D are shown in Figures 89,
90, 91.
Alternative E - This alternative is appropriate only for plants
that steam their furnish, except plant 4 and multiline mills that
have either one pulping system for each production line or pro-
duce only one product. It consists of splitting the process
systems at the decker. Excess machine white water is utilized to
wash the fiber on the decker. The discharge from the fiber
preparation system at approximately one percent dissolved solids
goes to an evaporator. The concentrate from the evaporator
following neutralization is pumped back into the white water
system. The condensate from this system at a consistency of 30
percent is utilized for fuel for the evaporators. The excess
machine white water not used in the washing operation is
discharged to an activated sludge system with design parameters
similar to Alternative C1 and D1 and is discharged following
treatment, A detailed summary of cost is presented in Table 91.
The costs of this alternative are as follows:
Initial Investment
Yearly Operation
and Maintenance
Total Yearly Cost
Subcategorv II
$1,540,800
496,700
$ 635,000
A reduction of 97% in BOD and 92% in suspended solids will be
achieved.
Alternative F - This alternative is applicable only for plants
with large land areas available. This alternative provides spray
irrigation of all plant waste waters. The system consists of a
holding pond followed by a dosing pond and an irrigation field
with underdrains. The cost for these units will be the same for
both treatment categories, however, two systems are considered.
The first is for northern climates where freezing conditions
366
-------
2 1,250,000
•5
o
° 1,000,000
Ul
i
tj 750,000 -
50O,OOO-
25O.OOO -
- 35O.OOO
- 300,000
2 50.OOO ^
5
9
- 200,000
o>
o
o
- 150,000
• 100,000
5O.OOO
UJ
2O
40 6O 80
BOD REDUCTION (%)
too
FIGURE 89 TOTAL INVESTMENT COST AND TOTAL YEARLY COST vs BOD
REDUCTION FOR ALTERNATIVE D - SUBCATEGORY,I OF THE
INSULATION BOARD INDUSTRY
367
-------
o
o
Id
s
£
Id
1,500,000 -
1,250,000 -
1,000,000 -
750,000 -
500,000 -i
250,000
20 40 60
BOD REDUCTION (%)
80
- 500,000
e
s
"o
400,000 g
O
- 300,000
- 200,000
- 100,000
<
IOC
FIGURE 90 TOTAL INVESTMENT COST AND TOTAL YEARLY COST vs BOD
REDUCTION FOR ALTERNATIVE D - SUBCATEGORY II Of THE
INSULATION BOARD INDUSTRY
368
-------
J,500,000 -
1.250,000 -
o
I
fe 1,000,000
o
o
u
UJ
750 ,000 -
500,000
250,000 -
20
i
40
60
60
BOD REDUCTION {%)
500.000
C
_o
"o
400,000 g
O
300,000 >!
o
- 200,000
- 100,000
100
FIGURE 91 TOTAL INVESTMENT COST AND TOTAL YEARLY COST VS BOD REDUCTION
FOR ALTERNATIVE D - SUBCATEGORY III OF THE INSULATION BOARD INDUSTRY
369
-------
TABLE 91
ITEMIZED COST SUMMARY FOR
ALTERNATIVE E FOR INSULATION BOARD
CO
-^1
O
ITEM
Evaporation:
Evaporator
Instrumentation
Erection
Holding Tanks (2)
Pumps
Product Storage Tank
Caustic Storage
SUB-TOTAL
Activated Sludge:
Nutrient & pH Control
Lagoon v/liner
Secondary Clarlfier
Aerators
Pipes, Valves and Fittings
Electrical (Misc)
INVESTMENT COSTS
Subcategory II
462,000-525,000
46,200
186,000-210,000
20,160-23,520
8,400
10,080-11,760
10,080-10,800
720,720-830,760
7,980
39,312-45,360
59,220
40,320-50,400
16,800
21,000
-------
TABLE 91 (cent.)
CO
ITEM
Instrumentation
Sludge Disposal
Thickner
Polymer Feed Equipt.
Coil Filter
Belt Conveyor
Building
SUB-TOTAL
Engineering & Contingencies
Land
TOTAL INVESTMENT
Operation and
COST
Sjabcategory II
8,400
31,920
10,920
111,720
36,960
37,800
422,352-438,480
240,045-266,540
5,000 (1.0 ha)
1,387.917-1,540,840
Maintenance
Evaporation
Operation and Maintenance
Electricity
Steam
SUB-TOTAL
109,620-137,050
59,976-78,910
101.546-125,830
271,142-341,790
-------
TABLE 91 (cont.)
Item
Activated Sludge
Operation and Maintenance
Power
SUB-TOTAL
TOTAL ALTERNATIVE E
Cost
Subcategory II
125,376-127,091
25,895- 27,788
151,271-154,879
422,413-496,669
CO
-------
occur. This system has a holding lagoon with a capacity of five
months which allows for containment for waste water produced
during the winter months when spray irrigation is not possible.
The second system, designed for plants in southern climates, has
a 30 day holding pond. This is necessary in the event that heavy
rains eliminate the possibility of spray irrigation. Prior to
the dosing pond, pH adjustments and nutrient additions may be
provided. The irrigation field has underdrains to collect the
treated water. A loading rate of 204,000 1/day/sq m was assumed
for the spray irrigation field. A detailed summary of costs are
presented in Table 92.
The costs for this alternative are as follows:
Initial Investment
Yearly Operation
and Maintenance
Northern
$2,009,200
79,500
Southern
$961,400
76,200
Total Yearly Cost $ 260,300 $162,700
A 99% reduction of both BOD and suspended solids is achieved.
A summary of costs and reduction benefits for all alternatives is
presented in Table 93.
Related Energy Requirement of Alternative Treatment and Control
Technologies
Based on information contained in questionnaires provided by
A.I.M.A. it is estimated that the plants for each subcategory
utilize the following quantities of energy for producing 272
kkg/day of insulation board:
Subcategorv
I
II
Electricity
kw hr/day
201,000
105,000-
243,000
Fuel
9.8 X 10«
6.8 X 108-
8.3 X 108
Total
Energy
Kg cal/dav
11.6 X 108
9.1 X 108-
9.3 X 108
Fuel may be in the form of oil, coal, gas, or wood, A major
portion of the energy required for producing insulation board is
for drying the mats in the driers.
The total increase in energy requirements for each of the
treatment alternatives is presented in Table 94. It should be
noted for all alternatives, except E, the increase in energy is
for electricity only. However, alternative E also has an
increased fuel requirement for producing the steam for the
373
-------
TABLE 92
ITEMIZED COST SUWIARY
FOR ALTERNATIVE F FOR INSULATION BOARD
Item
Holding Pond
Holding Basin
Pumps
Irrigation System
Control Building
Land
Engineering & Con-
tingencies
Initial Investment Costs
Northern
Costs
Operating and Maint.
Power
Southern
26,964
577,584
24,360
518,280
4,200
616,000
241,790
2,009,178
Operation and Maintenance
;. 68,124
11,424
79,548
26,964
139,104
24,360
302,400
4,200
360,000
104,376
961,404
64,764
11,424
76,188
37!*
-------
TABLE 93 SUMMARY OF COST AND BENEFITS OF TREATMENT ALTERNATIVES
FOR THE MODEL INSULATION BOARD PLANT
GO
-^
cn
AT ternati ve Subcategory
A All
B I
II
C-l I
II
C-2 I
II
D-l I
II
D-2 I
II
E II
F Northern
Southern
Incremental Total Total Yearly Total
Investment Investment Operating and Yearly
Cost Cost Maintenance Cost Cost
0 0
380,000
. - 380,000
954,100
1,095,600-
1,160,800
236,500 1,190,000
236,500 1,332,000-
236,500 1,397,300
954,100
1,095,600-
1,160,800
105,660 1,059,800
105,660 1,201,200-
105,660 1,266,500
1,387,900-
1,540,800
2,009,200
961,400
0
34,400
72,400-
91,300
216,000
264,100-
287,800
235,900
283,200-
306 ,900
216,700
264,100-
287,800
222,800
270,200-
293,900
422,400-
496,700
79,500
76,200
0
87,300
132,500-
155,100
302,600
362,700-
392,300
343,100
403,100-
432,700
302 ,600
362,700-
392,300
318,200
378,300-
407,900
547,300-
635,400
260,300
162,700
BOD
Reduction
Percent
0
85
85
90
90
97
97
90
90
97
97
97
99
99
SS
Reduction
Percent
0
70
70
70
70
70
70
70
70
91
91
92
99
99
-------
TABLE 94 POWER REQUIREMENTS OF TREATMENT ALTERNATIVES
IN THE INSULATION BOARD INDUSTRY
Treatment
Alternative
cn
C-2
D-l
D-2
E
F
Treatment Electrical
Sub-Category Requirement (Kw-Hr/Day)
ALL -0-
I 4,300
II 9,670-
12,350
I 5,760
II 11,130-
13,810
I 7,910
II 13,280-
15,960
I 5,760
II 11,130-
13,810
I 5,950
II 11,320-
14,000
I 12,170*-
15,130*
ALL 1,620
Percent increase
in requirement
over model plant
-0-
2.1
9.2-
5.1
2.9
10.fr-
5.7
3.9
12.6-
6.6
2.9
10.6-
5.7
3.0
10.8-
5.8
6.1*-
6.2*
-cl.5
*Additional non-electrical energy to heat the evaporators of l.AxlO8 - 1.7sl08 kg-cal
is required for subcategory II. This amounts to 17-25 percent of present fuel usage.
-------
evaporators. This amounts to between 17X and 25% of the
fuel requirement for Subcategory II.
Non-Mater Quality Aspects
present
Alternative A assumes no additional treatment and control
technologies are added to the model plant. Therefore, there are
no non-water quality aspects to be considered.
Alternative B consists of adding an aerated lagoon system
followed by a small settling lagoon to Alternative A. This
system has all of the problems usually associated with biological
treatment plus several more, including the necessity for pH
control and nutrient addition. Another problem is that the
biological sludge from this process does not readily settle.
This can frequently cause high suspended solids in the effluent.
Temperature not only has an effect on the biological reaction
rates but, apparently to some extent, on the settling rates of
the biological solids.
The system is sensitive to shock loads and to shut down and start
up operations of the manufacturing process. The equipment needed
for the aerated lagoon system is available on the market;
however, up to a year or longer may be required from initiation
of design until beginning of operation. The energy requirements
are high. There are no noise or radiation effects associated
with the process.
Alternative C1 consists of an activated sludge process.
Activated sludge treatment of insulation board waste water can be
quite effective. However, the system has all of the problems
associated with activated sludge treatment of domestic waste plus
several more. For instance, pH control and nutrient addition are
required. A major problem associated with the process is that
the biological solids do not readily settle. This can cause high
suspended solids in the effluent. Temperature not only effects
the biological reaction rates, but apparently the settling rate
of the biological solids.
Activated sludge systems require constant supervision and
maintenance. They are quite sensitive to shock loads and to
start up and shut down operations of the manufacturing process.
The equipment needed for the process is available in the market;
however, up to two years may be required from initiation of
design until beginning of plant operation. The energy
requirements are high. There is essentially no noise or
radiation effects associated with the process. Sludge is a
problem and can result in odor problems.
Alternative C2 consists of the addition of an aerated lagoon to
the activated sludge system. This alternative provides for an
increase in treatment efficiency above that achieved by activated
sludge alone. All of the problems associated with biological
treatment as discussed in Alternative B and C1 apply to this
Alternative C2. There is essentially no noise or radiation
377
-------
effects with the process. The energy requirements are high as
discussed previously.
Alternative D1 is the same system as described in Alternative C1.
Alternative D2 consists of the addition of mixed media filtration
facilities to Alternative C1 and recycle of 70 percent of the
effluent. This is done to remove the high suspended solids often
found in the effluent of the activated sludge process so that the
water can be recycled. This alternative has all of the problems
discussed in Alternative C1 plus those associated with the
operation of filtration facilities. Mixed media filtration is
quite effective for removing suspended solids from the effluent
of activated sludge systems; however, excessively high suspended
solids concentrations can quickly blind the filter and cause high
frequency of backwash. Recycle of filtered effluent is not a
proven technology as the long term effects are unknown. Possible
buildup of dissolved solids and increased problems of slime
growths and corrosion may result.
The equipment for this process is readily available on the
market. The estimated time of construction is within the two
year time period allocated for the construction of the activated
sludge process. The energy requirements are high as discussed
previously. There is essentially no noise or radiation effects
associated with the process.
Alternative E consists of the addition of two separate waste
water handling systems to Alternative A. This requires that the
white water system be split at the decker into fiber preparation
and machine white water systems. Slowdown from the fiber
preparation white water system is evaporated in a multi-effect
evaporator. Condensate is reused as partial makeup for the
machine white water system and concentrated waste is mixed with
sander dust and burned in a boiler.
This system is applicable only in plants that steam their furnish
as it is most applicable when high concentrations of dissolved
solids are present from the steaming operation. This system
requires either separate pulping systems for each forming machine
or that the white water from multi-machine plants are compatible.
The requirements of separating the white water systems may not be
practical in many plants because of the high cost of plant
modifications. Evaporation systems must be fed at a relatively
constant rate. Maintenance requirements are high because of the
nature of the material being evaporated. The evaporator must be
cleaned out weekly if not more frequently. Evaporation equipment
can be obtained on the market; however, a two year period from
initiation of design until start up is not reasonable. Noise and
radiation effects are minor, but energy requirements can be
significant.
The blowdown from the machine white water system is treated in an
activated sludge process. This process has the same problems
associated with it as the activated sludge process discussed in
378
-------
Alternative C1. Noise and radiation effects of this system are
minor.
Alternative F consists of spray irrigation of all waste water
from a plant. Spray irrigation of waste water depends on
biological degradation of waste by soil bacteria, adsorption and
ion exchange reactions within the soil, and filtration on the
soil surface. These factors are greatly influenced by soil type,
effluent qualities, water table, and weather conditions. Weather
conditions, especially freezing temperature and high rainfall,
require that provisions be made for waste water storage until
such time as conditions improve. Spray irrigation fields require
constant supervision and maintenance. They are sensitive to both
hydraulic and organic shock loads. The pH should be controlled
and nutrients added. The equipment needed for spray irrigation
is available on the market; however, up to two years might be
required for design and construction prior to operation. The
availability of suitable sites for spray irrigation may be a
limitation. There is essentially no noise or radiation effects
associated with the process.
The cost estimates contained in this document are based on actual
preliminary cost estimates for waste treatment systems defined in
Section VII (Control and Treatment Technology) for a typical
model plant defined in section V (Water Use and Waste
Characterization) of the particleboard industry. The land costs
are assumed to be $1500 an acre based on the assumption that the
plant is located near a small town.
The particleboard plant discharges on an intermittent basis
11,000 1 (3,000 gal) per day of waste water. It has a production
of 270 metric tons (300 tons) per day. The 1.1,000 1 (3,000 gal)
of waste water consist of 7,700 1 (2,000 gal) per day of
housekeeping water, i.e. water used for general cleanup; 1900 1
(500 gal) per day of resin blender wash water; and an additional
1900 1 (500 gal) per day consisting of miscellaneous flows
including periodic washdown of storage tanks, pressurized refiner
start-up and water from the press pit.
The plant presented here for discussion is considered to be
typical of the particleboard industry at this time. However, the
model plant in the future may include both a chip washer and a
scrubber for air emissions control.
Cost and Reduction Benefits of Alternative Treatment and Control
Technologies
Alternative A - This alternative assumes no treatment of waste
water. There is no cost involved and no reduction benefits.
Alternative B - This alternative consists of screening of waste
water prior to discharge to a septic tank and drain field. A
detailed summary of cost is presented in Table 95.
379
-------
TABLE 95
ITEMIZED COST SUMMARY
FOR ALTERNATIVE B FOR PARTICLE BOARD
Initial Investment
Item
Screens and Building
Septic Tanks Drain Field
Land (0.032 ha)
Engineering and Contingencies
Operation and Maintenance
Operation and Maintenance
Power
Cost
$6,950
4,032
117
2,306
$13,405
$3,528
63
$3,591
380
-------
The cost of this alternative is as follows:
Initial Investment $13,400
Yearly Operation
and Maintenance 3,600
Total Yearly Cost $ 4,800
This alternative provides for no discharge of pollutants.
Alternative C - This alternative consists of spray irrigation of
all waste water. Two systems were costed because of different
climatic conditions. The one for northern climates is designed
with a holding pond capable of holding a five month waste flow
during freezing weather. The southern climate plant was designed
with the capability to hold all waste water flow during periods
of heavy rainfall only. A detailed summary of costs are
presented in Table 96.
The costs for this alternative are as follows:
Northern Southern
Initial Investment $23,800 $16,000
Yearly Operation
and Maintenance 7,000 7,400
Total Yearly Cost $ 9,100 $ 8,800
This alternative provides for no discharge of pollutants.
Alternative p - This alternative consists of spray evaporation of
all waste water. Systems were designed for four climatic regions
where particleboard plants normally occur. A detailed summary of
costs are presented in Table 97.
The costs for this alternative are presented below:
Initial Investment
Yearly Operation
and Maintenance
Total Yearly cost
Alternative E - This alternative consists of spraying all waste
water on incoming raw materials. A detailed summary of costs are
presented in Table 98.
The costs for this alternative are as follows:
SE
$22,678
5,893
$ 7,934
NE
$19,299
6,157
$ 7,894
NW
$35,023
10,815
$13,967
NC
$19.997
6,596
$ 8,396
381
-------
TABLE 96
ITEMIZED COST SUMMARY
FOR ALTERNATIVE C FOR PARTICLEBOARD
Initial Investment Costs
Item
Northern
Transfer Pump $ 504
Spray Pump 1S512
Storage Tank 3,948
Pond 9,045
Irrigation Spray System 1,680
Land 3,600
Engineering and Contingencies 3,505
$23,794
Operation and Maintenance
Operation and Maintenance 6,939
Power 48
$6,987
Cost
Southern
504
1,260
2,772
5,774
1,260
1,950
2,430
$15,950
7,312
55
$7,367
382
-------
TABLE 97
ITEMIZED COST SUMMARY
FOR ALTERNATIVE D FOR PARTICLEBOARD
Initial Investment Costs
Item
Southeastern
Cost
New England Northeastern North Central
Ponds, Control
Structures, Lining 16,126
Land 3,165
Engineering &
Contingencies 3,387
13,718 24,977 14,220
2,700 4,800 2,790
2,881 5,246 2,987
$22,678
$19,299
$35,023
$19,997
Operation and Maintenance
Operation &
Maintenance
Power
4,093
1,800
4,185
1,972
6,870
3,945
4,459
2,137
$5,893
,157
$10,815
$6,596
383
-------
TABLE 98
ITEMIZED COST SUMMARY
FOR ALTERNATIVE E FOR PARTICLEBOARD
Initial Investment Costs
Item Cost
Float Activated Pump $210
Float and Switch 168
Make-up Water Control Valve 336
Twin 5-day Detention Pits with Sump Pump and
Concrete 24,066
Spray Nozzles and Piping 252
Land (.011 hec.) 41
Engineering and Contingencies 5,257
$30,330
Operation and Maintenance
Operation and Maintenance
Power
$3,892
32
$3,924
38^
-------
Initial Investment $30,330
Yearly Operation and Maintenance 3,924
Total Yearly cost $ 6,654
This alternative provides for no discharge of pollutants.
Alternative F - This alternative consists of spraying all waste
water on hog fuel for boiler. A detailed summary of costs are
presented in Table 99.
The costs for this alternative are as follows:
Initial Investment $20,648
Yearly Operation and Maintenance 3,940
Total Yearly Cost $ 5,790
This alternative provides for no discharge of pollutants.
Summarized costs for all alternatives are presented in Table 100.
It should be noted that all alternatives provide for no discharge
of all pollutants from the manufacturing process.
Related Energy Requirements of Alternative Treatment and control
Technologies
Based on information contained in survey data provided by the
National Partxcleboard Association, it is estimated that the
model particleboard plant uses 50,000 kw hr/day of electricity to
produce 300 tons/day of board. In addition, approximately
163,296 kg/day (360,000 Ib/day) of steam at 15 atms. is required.
The steam is usually produced with oil, gas, coal, or wood fired
boilers. The model plant was estimated to use 1,416,000 I/day
(50,000 cu ft/day) of gas and 51.7 kkg/day (57 tons/day) of wood
and oil or coal. This, however, may vary among plants.
The total increased energy requirements for treatment
alternatives are presented in Table 101. The increased energy
requirements consist of only electricity and in all cases the
increased electrical requirements amount to less than 1.1% of the
plant's present electrical usage.
Non-Water Quality Aspects of Alternative Treatment and control
Technologies
Alternative A consists of no treatment of waste water and,
therefore, there are no non-water quality aspects involved.
Alternative B consists of the use of screens, septic tanks, and
drain fields. Provisions are made to pump out the septic tanks
monthly and dispose of the ^material by land spreading. This
system is one of the simplest^for treating small quantities of
385
-------
TABLE 99
ITEMIZED COST SUMMARY
FOR ALTERNATIVE F FOR PARTICLEBOARD
Ini ti al Construct!on Cos ts
Item
Screens, Pump and Building
Sump, Concrete
Land (.0073 ha)
Engineering and Contingencies
Operation and Maintenance
Operation and Maintenance
Power
Cost
$7,160
9,882
27
3,579
$20,684
$3,877
_, 63
$3,940
386
-------
TABLE 100
SUMMARIZED COST OF TREATMENT
ALTERNATIVES FOR PARTICLEBOARD PLANTS
Alternative
A
B
C
D
CO £
00 t
F
Region
ALL
ALL
Northern
Southern
Southeastern
New England
Northwestern
; North Cent.
ALL
ALL
Initial Inves.
$ -0-
13,405
23,749
15,950
22,678
19.299
35,023
19,997
30,330
20,648
Operation & Maint.
$ -0-
3,591
6,987
7,367
5,893
6,157
10,815
6,596
3,924
3,940
Total Yrly. Cost
$ -0-
4,797
9,128
8,803
7,934
7,894
13,967
8,396
6,654
5,798
-------
waste. The major problem which might be experienced would be
slug loads of solids that would carry through the septic tanks
and plug the drain field.
The equipment necessary for this alternative is readily
available. The time required from initial design to completion
of construction should not exceed three months. There is
essentially no noise or radiation effects associated with this
process.
Alternative C consists of spray irrigation of all waste water
from a particleboard plant. Spray irrigation is an effective
means of waste disposal if suitable land can be found for the
spray field. The volume of waste from a particleboard plant is
relatively small and low loading rates should result in no
discharge to navigable waters. Spray irrigation systems are
influenced by weather conditions. Provisions must be made for
storing waste water in northern climates during freezing
conditions. Provisions must be made for waste storage in areas
of heavy rainfall to prevent excess hydraulic loading of the
spray field.
The equipment needed for the installation of spray irrigation
fields is available on the market, however, up to one year of
time may be required from start of design until completion of
construction. There is essentially no noise or radiation effects
associated with this process.
Alternative D consists of spray evaporation of all waste waters
from the particleboard plant. Spray evaporation can be effective
for disposal of small volumes of waste as experienced from the
particleboard industry. Problems associated with this process
are mainly associated with weather conditions. Evaporation is
directly related to quantity of waste, rainfall, relative
humidity, and temperature. In areas of heavy rainfall,
considerably more water must be evaporated in areas of low
rainfall. Freezing conditions in northern climates require
excess holding capacity to be designed for winter months.
Increase in suspended and dissolved solids because of evaporation
will in time require solids to be removed or another evaporation
pond to be installed.
The equipment needed for this process is available on the market;
however, up to one year may be required from initiation of design
until beginning of plant operation. There is essentially no
noise or radiation effects associated with the process.
Alternative E consists of spraying all waste water on the
incoming raw materials after settling of the waste. Problems
associated with this process are mainly associated with the
effect of the additional moisture on the raw materials. All
plants may not find it feasible to spray the waste water on the
raw material because of the effects of the additional moisture
content on the process although several plants are presently
using this system. The quantity of water to be sprayed on the
388
-------
TABLE 101
POWER REQUIREMENTS OF TREATMENT ALTERNATIVES IN
THE PARTICLEBOARD INDUSTRY
Treatment
Alternative
A
B
C
D
OO
CO
E
F
Region
ALL
ALL
Northern
Southern
Southeastern
New England
Northwestern
North Central
ALL
ALL
Treatment
Electrical
Requirement
(kw-Hr/Day)
-0-
7.5
6.4
7.5
256
280
559
278
4.5
7.5
Percent Increase
In Requirement
Over Model Plant
-0-
0.02
0.01
0.02
0.5
0.6
1.1
0.6
0.01
0.02
-------
raw material is relatively small compared to the weight of the
raw material; however, if the raw material is already high in
moisture content the additional moisture may cause problems in
the manufacturing operation.
The equipment needed for this system is readily available;
however, up to six months may be required from initiation of
design until start up of the process. There are essentially no
noise or radiation effects associated with the process.
Alternative F consists of spraying all of the waste water on
waste material utilized as fuel in a boiler. This is a feasible
and effective method of disposal of small volumes of waste water.
However, many plants do not burn waste material as fuel for their
boiler because of air pollution problems. Therefore, this
alternative depends on the existence of a hog boiler and its
continued ability to meet air pollution regulations.
The equipment required for this process is readily available on
the market; however, up to six months may be required from
initiation of design until start up of the process. There are
essentially no noise or radiation effects associated with the
process.
FINISHING WITH WATER REDUCIBLE MATERIALS
The cost estimates developed herein are applicable to a finishing
plant generating a volume of waste water of 750 I/day from clean
up operations involved in the use of water base liquid finishing
materials, as discussed in Section V. The plant produces 10
million sq m on a 6.35 mm basis (107.6 million sq ft on a 0.25 in
basis) per year of prefinished paneling. It is assumed to have
the following:
1.
2.
3.
4.
5.
Two identical finishing lines, both operating on a 2H
hour per day, seven day per week basis.
Each line consists of 3 water base material applicating
machines.
Each applicating machine is washed
requiring 75 1 (20 gal) of water/wash.
once each day
Material storage and mixing vats require a total of 300
1 (80 gal) of washwater/day.
Total waste water generated is 750 Ipd (200 gal/day) and
will occur 365 days/year.
The typical plant was selected on the basis of the volume of
waste water generated. Volumes of waste water generated from
finishing operations range from 75 Ipd (20 gal/day) to 1,100
I/day (300 gal/day) as pointed out in a previous section. There-
fore, a total volume of 750 I/day (200 gal/day) can be assumed to
be a typical value.
390
-------
Cost and Reduction Benefits of Alternative Treatment and Control
Technology
The recommended alternative treatment methods for this
subcategory are similar to Alternatives B, C, D, and F for Model
1 for fabricating with the exception that screening of the waste
water is not required. The revised summaries of costs of
treatment for the applicable alternatives are presented below.
Detailed cost estimates for each alternative are the same as
those presented for the fabrication subcategory without
screening.
Alternative A - This alternative consists of no control and
treatment. No costs are associated with this alternative nor are
any reduction benefits achieved.
Alternative B - This alternative consists of a spray evaporation
pond as described for fabrication.
The Costs of Control and Treatment are as follows;
Total investment costs $24,100
Total yearly Operating
and Maintenance 1,700
Total Yearly Costs $ 3,800
100 percent reduction of pollutants is achieved.
Alternative C - This alternative consists of discharge to a
holding tank followed by spraying on hogged fuel prior to
burning.
The costs of control and treatment are as follows:
Total Investment Costs $6,200
Total Yearly Operating
and Maintenance 3,200
Total Yearly Costs $3,700
100 percent reduction is achieved,
Alternative p - This alternative consists of discharge to a
holding tank followed by trucking to land spreading.
The costs of control and treatment are as follows:
Total Investment Costs $7,100
Total Yearly Operating
and Maintenance 1,600
391
-------
Total Yearly Costs
100 percent reduction is achieved.
$2,200
Alternative F - This alternative consists of discharge to a
municipal sewer.
The costs of control and treatment are as follows:
Total Yearly Operating
and Maintenance
Total Yearly Costs
100 percent reduction is achieved.
$ 300
$ 300
A summary of alternative costs for treatment of waste waters from
this subcategory is presented in Table 102.
Related Energy Requirements of Alternative Treatment and control
Technology
The industries represented by this subcategory are extremely
diverse in terms of product produced and energy consumed.
Therefore, no information is available which is representative of
energy requirements for finishing operations.
The costs presented in Table 103 are the anticipated annual
energy costs for the alternative treatment and control
technologies.
Non-Water Quality Aspects of Alternative Treatment and control
Technologies
The non-water quality aspects of the various alternatives are
anticipated to be negligible. However, disposal of wastes by
landspreading must be carefully controlled to prevent groundwater
and surface water contamination. There are no air pollution,
noise, or radiation effects from the installation of any of the
above systems.
392
-------
TABLE 102
SUMMARY OF ALTERNATIVE COSTS
FOR FINISHING WITH WATER REDUCIBLE MATERIALS
CO
CD
CO
Alternative
A
B
C
D
E
F
Percent Reduction
-0-
100
100
100
100
Investment Costs
-0-
$24,100
$ 6,200
$ 7,100
Not Applicable
-0-
Total Yrly. Operating
Costs
-0-
$1,700
$3,200
$1,600
$ 300
Total Yrly.
Costs
-0-
-$3,800
$3,700
$2,200
$ 300
-------
TABLE 103
ANTICIPATED ANNUAL ENERGY COSTS FOR
ALTERNATE CONTROL TECHNOLOGIES FOR FINISHING
WITH WATER REDUCIBLE MATERIALS
Alternative
A
B
C
D
E
F
Model-1 Costs
-0-
$144
$ 20
$ 20
Not Applicable
-0-
33k
-------
SECTION IX
BEST PRACTICABLE CONTROL TECHNOLOGY CURRENTLY AVAILABLE
INTRODUCTION
The effluent limitations which must be achieved by July 1, 1977
are to specify the degree of effluent reduction attainable
through the application of the Best Practicable Control
Technology Currently Available. Best Practicable Control
Technology Currently Available is generally based upon the
average of best existing performance by plants of various sizes,
ages, and unit processes within the industrial category or
subcategory. This average is not based on a broad range of
performance with the timber products processing subcategory but
rather based on levels of performance achieved by exemplary
plants.
Consideration must also be given to:
a. The total cost of application of technology
in relation to the effluent reduction benefits
to be achieved from such application;
b. The size and age of equipment and facilities involved;
c. The process employed;
d. The engineering aspects of the application of various
types of control techniques;
e. Process changes;
f.
Non-water quality environmental impact (including
energy requirements); and
g. Availability of land for use in waste water treatment
disposal.
Best Practicable Control Technology Currently Available
emphasizes treatment facilities at the end of a manufacturing
process but also includes the control technologies within the
process itself when these are considered to be normal practice
within the industry.
A further consideration in the determination of BPCT is the
degree of economic and engineering reliability which must be
established for the technology to be considered "currently
available." As a result of demonstration projects, pilot plants,
and general use, there must exist a high degree of confidence in
the engineering and economic practicability of the technology at
the time of construction or installation of the control
facilities.
395
-------
In addition to the above factors, consideration should be given
to plants or unit processes that form parts of industrial
complexes. Such complexes may be composed of various
combinations of some or all of the subcategories discussed
herein, as well as operations such as pulp and paper production,
furniture manufacturing, or other processes not covered in this
study. While a numerical addition of pollutant loads from all
unit operations will yield the total effluent load from a
complex, several factors may affect the application of available
control and treatment technology. In treatment of its total
waste water discharge the complex may have the advantages of
economies of scale, improved potential for water recycle, and
joint use of a unit process. It may also have the disadvantages
of lack of available land, substantial previous investments in
control and treatment technology that may not be applicable to
the proposed guidelines, alteration of waste water treatability
as a result of the combining of waste streams, or, if waste must
be treated separately, the additional expense of segregation of
the combined waste streams. The effluent guidelines and
standards presented below reflect consideration of these factors.
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF BEST
PRACTICABLE CONTROL TECHNOLOGY CURRENTLY AVAILABLE FOR WET STORAGE
Based on the information contained in Sections III through VIII
of this document, it has been determined that the application of
the best practicable control technology for wet storage
operations results from the control of the discharge from pond
storage situations during periods when precipitation is less than
evaporation. Control of the volume discharged from a wet
decking operation is achieved by process management. When a
discharge is allowed from a wet storage facility a particle size
limit, maximum size 2.54 cm (1.0 in.) diameter, is proposed, in
addition to a pH range limitation.
Identificat ion
Available
of Best Practicable Control Technology Currently
The technology identified as the best practicable control
technology currently available involves the reasonable control of
the discharge of extraneous process waters into the wet storage
pond or recycle pond serving a wet deck. Appropriate control
technology may possibly involve the relocation of the discharge
point of the pond away from activity points on the pond.
Activity points include points where logs are deposited in the
pond, the location where logs are taken to the processing plant,
areas where pond boats have activity stirs up the pond bottom.
In ponds where saws are used to trim log ends, sawdust and bark
materials can be relatively easily kept out of the pond by
utilizing water jets to force the waste material into a specific
location where it either settles and sinks for removal from the
pond waters or forced out the water to be shoveled out and
disposed.
396
-------
The utilization of various types of discharge systems will help
to achieve limitations on debris. Common practice in the
industry is the use of a floating boom to retain floating
materials within the body of water. Also submerged weirs are
utilized to retain floating materials. Another mechanism that
may be effective is the inverted outlet. This involves placing
an inverted drum over a discharge pipe. Floating materials
cannot reach the discharge pipe unless it passes underneath the
edge of the drum.
Engineering Aspects of Control Technology Applications
Treatment and control technology as it currently exists for the
wet storage subcategory involves, in most cases, the application
of relatively uncomplicated technology. The proposed guidelines
and standards can be achieved by the use of floating booms,
submerged weirs, inverted or submerged discharges, and/or a
quiescent area before discharge.
Cost of Application
The total investment costs for the treatment and control scheme
for the wet storage subcategory are estimated to be less than
$3,000 for a pond storage facility and slightly more for a wet
decking operation. It should be kept in mind that these costs
are maximum costs and that a significant percentage of the
facilities that will be covered by these regulations are either
already achieving these limitations or can achieve them with
either a modification of operating procedures or a minimal amount
of expense.
Non-Water Quality Environmental Impact
The non-water quality environmental impact will be relatively
minor for the application of Best Practical Control Technology
Currently Available. No air pollutants will be produced. The
solid wastes will be landfilled. The varying water levels in the
ponds may, at the end of the dry season, expose aesthetically
displeasing mud or sludge deposits. However, the pond can have a
pleasing appearance if maintained properly.
Factors to be Considered in Applying Effluent Limitations
The proposed guidelines and standards for wet storage operations
are based in part on the consideration that reasonable water use
is practiced in the manufacturing operation that makes use of the
wet storage facility. The volume limitation on discharge from a
wet storage facility, particularly a pond, cannot be achieved if
control is not maintained over the volume of process water
discharged to the wet storage water system. Although there is
not a specific or absolute limitation on the amount or sources of
water going into the system, it is recognized that some process
waters, such as glue system water, binder washing water, process
waters containing oil and grease, and other process waters may
397
-------
contain pollutants which if they come in contact with navigable
waters, will have an adverse effect on water quality.
The diversion of extraneous influents from surface runoff is a
consideration also. While it is not possible to develop the
costs associated with diversion because it is so geographical and
climatic dependent, diversion should be considered as a tool
available to achieve the minimization of the discharge of
pollutants.
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF BEST
PRACTICABLE CONTROL TECHNOLOGY CURRENTLY AVAILABLE FOR THE LOG
WASHING SUBCATEGORY
Based on the information contained in Sections III through VIII
of this document, it has been determined that the application of
the Best Practicable Control Technology Currently Available is
that resulting from recycle of the log wash effluent. The
effluent levels obtainable for this degree of waste water
reduction is no discharge of process waste water pollutants to
navigable waters.
Identification
Available
of Best Practicable Control Technology Currently
The best practicable technology currently available consists of
screening the log wash effluent followed by sedimentation to
remove grit and suspended solids and screening preceding recycle
of the effluent to the log washing operation.
Recycle of log wash effluent is considered currently available
practicable technology since total recycle is being accomplished
by at least two sawmills. The technology for total recycle is
uncomplicated in nature and should be achievable by July 1, 1977.
Costs of Application
The costs of attaining the recommended effluent reductions set
forth herein are presented in Section VIII, Cost, Energy, and
Non-Water Quality Aspects and are summarized below.
Costs of Treatment and Control:
Incremental Investment Costs: $27,600
Total Investment Costs: $27,600
Total Yearly Operating Costs: $14,700
Total Yearly Costs: $17,200
Non-Water Quality Environmental Impact
The non-water quality environmental impact of the application of
a closed system for a log washing operation may be considered to
398
-------
be negligible. There is no appreciable increase in energy
consumption for log washing with the application of the
recommended technology. The material removed from the logs,
primarily inorganic in nature, will vary in amount, depending on
the conditions of harvesting and transportation. The disposal of
this material by landfill should not have an adverse impact on
the environment.
Factors to be Considered in Applying Effluent Limitations
No discharge of pollutants should be attainable for all
operations specifically designed to wash logs. This limitation
is not intended for application to operations such as hydraulic
debarking and wet storage wherein log washing may occur
incidentally.
It should be noted that the no discharge limitation and the costs
associated with the application of this limitation were
predicated on the assumption that extensive changes in the mill
feed will not be required.
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF BEST
PRACTICABLE CONTROL TECHNOLOGY CURRENTLYAVAILABLE FOR THE
SAWMILL AND PLANING MILL SUECATEGORY
Based on the information contained in Sections III through VIII
of this document, it has been determined that the application of
the Best Practicable Control Technology Currently Available is
that resulting from proper inplant management and control. The
effluent level obtainable by the application of this no discharge
of waste water pollutants to navigable waters.
Identification of Best Practicable Control Technology Currently
Available
The Best Practicable Control Technology Currently Available
consists of the application of inplant management practices as
discussed in Section VII, control and Treatment Technology.
These included management of water use, prevention of the
contamination of non-contact cooling water.
Engineering Aspects of Control Technology Applications
The inplant control measures recommended for sawmills and planing
mills are currently practicable in that all have been observed at
various mills.
Costs of Application
As stated in Section VIII, the cost of achieving no discharge in
sawmills and planing mills as defined in this document is
considered to be negligible.
399
-------
Non-Water Quality Environmental Impact
There are no known non-water quality aspects involved in the
application of a no discharge limitation.
Factors to be Considered in Applying Effluent Limitations
The pertinent factors to be considered in applying effluent
limitation to sawmills and planing mills is the definition of a
sawmill. In other words, by definition the sawmill does not
include raw material storage or handling, log washing, debarking,
power or steam generation or fabricating and finishing
operations. Thus, the effluent limitation of zero discharge for
sawmills and planing mills is only applicable to the manufacture
of lumber from debarked logs.
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF BEST
PRACTICABLE CONTROL TECHNOLOGY CURRENTLY AVAILABLE FOR THE
FINISHING SUBCATEGORY
Based on the information contained in Sections III through VIII
of this document, it has been determined that the application of
the Best Practicable Control Technology Currently Available is
evaporation, incineration, land spreading or recycle of process
washwaters for reuse as washwater or makeup water. The effluent
level obtainable by the application of this technology is no
discharge of process waste water pollutants.
Identification of Best Practicable Control Technology Currently
Available
The best practicable control technology currently available
consists of one or more of the following alternatives:
1. Evaporation by the use of spray evaporators.
2. Trucking to landspreading.
3. Incineration by spraying of hogged fuel prior to burning.
U. Recycle of glue system water
Engineering Aspects of Control Technique Applications
Recycle of glue washwater for reuse as washwater is a currently
practicable technology in the plywood industry. It has been
observed in at least four U. S. plywood plants and has been
reported by Haskell to be utilized in a European plywood mill.
The feasibility for transfer of this technology to the water
soluble glue using segment of the finishing subcategory has been
recognized by representatives from government and industry. It
should be noted, however, that the finishing subcategory contains
a wide variety of plants using a wide variety of glue applicators
and various types of glues. Therefore, the recycle of washwater
may not be practicable in all cases. Limitations on recycle may
exist for certain types of resins although there is presently no
information available to substantiate any such limitation. These
koo
-------
and other aspects will influence the determination of a treatment
alternative but should not affect the attainment of a zero
discharge limitation. All of the recommended alternatives are
practicable since all have been observed at various finishing
plants utilizing water reducible finishing materials.
Costs of Application
The investment costs of achieving the proposed guidelines and
standards range between $0 and $27,000 with a range of operating
costs between $300 and $3200.
Non-Water Quality Environmental Impact
Because of the relatively small volumes of waste water associated
with this subcategory the non-water quality aspects including
energy consumption of the various alternatives were assumed to be
negligible in Section VIII. However, as all the recommended
alternatives result in no discharge to pollutants, the best
practicable technology is that technology which most
significantly reduces the potential for environmental impact.
Recycle of washwater for reuse as washwater accomplishes no
discharge of pollutants while not increasing the potential for
air pollution as may be the case with incineration, without
increasing the potential for groundwater pollution as may be -the
case with evaporation ponds, without increasing the potential for
surface water contamination as may be the case with land
spreading, and with the least energy consumption of all the
recommended alternatives other than discharge to municipal
sewers.
Factors to be Considered in Applying Effluent Limitations
The no discharge limitation for the finishing subcategory
utilizing water soluble adhesives is considered to be attainable
in all cases. However, since there are a wide variety of types
of mills utilizing a variety of water soluble adhesives and
various types of applicators, there may exist limitations on the
adoption of recycle as a control technique. In those cases where
recycle of washwater for reuse as washwater may be demonstrated
to not be a practicable technology one of the following
alternatives will be applicable:
1. Incineration via spraying the glue wastes on
hogged fuel prior to burning.
2. Disposal by controlled land spreading.
3. Discharge to municipal sewer.
U. Evaporation
The factors which may contribute to the necessity for adopting
one of the above alternatives may be:
1. Impracticality of collecting several small
waste streams for where these streams are
-------
currently discharged separately to a municipal
sewer.
2. A particular type of adhesive may not lend itself
to extended ^recycling because of deterioration of
resin solids or buildup of dissolved solids.
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF BEST
PRACTICABLE CONTROL TECHNOLOGY CURRENTLY AVAILABLE FOR THE
INSULATION BOARD SUBCATEGORIES
Based on the information contained in Sections III through VIII
of this document, a determination has been made that the degree
of effluent reduction attainable and maximum allowable discharge
in the insulation board industry, based on the application of the
best practicable control technology currently available is set
forth in the following table.
30-Day Average
Subcateaorv
I
II
Subcategorv
I
II
Total
BODS Suspended solids
kg/kkg
1.25
3.75
Ib/ton kq/kkg
2.50 3.13
7.50 3.13
Dailv Maximum
Ib/ton
6.25
6.25
BODS
kg/kkq
3.75
11.3
Ib/ton
7.50
22.6
Total
Suspended Solids
kg/kkg
9.UO
9.UO
6-9
6-9
6-9
6-9
Identification of Best Practicable Control Technology Currently
Available
Insulation board is manufactured in a manner discussed in detail
in Section III. The wastes are derived and characterized in
Section V and treatment and control technologies in Section VII.
The Best Practicable Control Technology Currently Available is
treatment of the total waste water discharge by biological
treatment possibly with pH adjustment and nutrient addition prior
to the biological treatment process. Disposal of waste sludge is
by drum filtration followed by disposal of the dewatered sludge.
«t02
-------
Engineering Aspects of Control Techniques Applicable
The levels of technology summarized above and the effluent
reductions suggested are currently obtained by plants in both
subcategories. Information obtained from 16 insulation board
plants indicated a typical waste water discharge of 54,250 1/kkg
(3,000 gal per ton) for all subcategories. Raw waste water
characteristics of the model plant are 10 kg/kkg (20 pounds per
ton) of suspended solids for all categories and BOD loads as
follows: Category I, 12.5 kg/kkg (25 pounds per ton); and
Category II, 37.5 kg/kkg (75 pounds per ton). The treatment and
control technology summarized above is in use in at least one
manufacturing plant of each subcategory of the insulation board
industry, and each has demonstrated a high degree of engineering
reliability.
The equipment needed for the process is available on the market;
however, up to two years may be required from initiation of
design until beginning of plant operation. Once plant operation
is initiated there will be at least a six-week start-up period
required for process stabilization.
There are no significant process changes required. The addition
of certain capabilities and implementation of water recycle and
conservation practices will be needed to meet these limitations.
Cost of Application
The cost of obtaining the recommended effluent limitations set
forth herein for the model plants are presented in Section VTII,
Cost, Energy and Non*Water Quality Aspects and summarized below:
Subcategory
I-
II
Investment
$ 954,100
1,095,600-
1,160,800
Yearly
$302,600
362,700-
392,300
% Increase
in Capital Cost
of New Plant
(12.6 Million)
7.6
8.7-
9.2
Non^Water Quality Environmental Impact
The implementation of the above treatment technologies as
discussed in Section VIII relys on the ultimate disposal of the
waste activated sludge on the land. The energy requirement as
presented in Section VIII will account for less than 11 percent
of the present electrical requirement of the model plants of all
subcategories.
-------
Factors to be Considered in Applying Effluent Limitations
As discussed in Section VIII, activated sludge systems are
sensitive to shock loads resulting from start-up or process
malfunctions- Systems of this type require trained operating
personnel to achieve optimum treatment efficiency. It should be
noted that there are certain limitations on the efficiency of
biological waste water systems in northern climates where
freezing conditions occur. Upset conditions resulting from any
of the above reasons may result in an increase in the amount of
suspended solids being discharged.
During the start-up period the waste water effluent from the
treatment system may exhibit large variations in both BOD and
suspended solid discharges,
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF BEST
PRACTICABLE CONTROL TECHNOLOGY CURRENTLY AVAILABLE FOR THE
PARTICLEBOARP SUBCATEGORY
Based on the information contained in Sections III through VIII
of this Document, it has been determined that the effluent level
obtainable for particleboard manufacture by the application of
the Best Practicable Control Technology Currently Available is no
discharge of process waste water pollutants. This does not apply
to uncontaminated cooling water, roof and yard runoff, and waters
resulting from the handling and storage of raw materials.
Identification of Best Practicable Control Technology Currently
Available
Particleboard is manufactured in a manner discussed in detail in
Section III. The waste derived and characterized in Section V
and treatment and control technologies in Section VII. The best
practical control technology currently available which will
result in elimination of the discharge of pollutants requires the
implementation of one of one of the following:
1. Screening the total waste water flow prior to discharge
to a septic tank and drain field.
2. Spray irrigation of the waste water.
3. The evaporation of all waste water in a spray evapora-
tion pond.
U. Spraying all waste water on incoming raw material.
5. Spraying all waste water on hog fuel.
Engineering Aspects of Control Technologies Applicable
The application of the technologies summarized above and the
effluent reductions suggested are reported to be obtained by 13
plants. Each of the treatment technologies listed above are
currently in use in at least one particleboard plant (or in the
case of spray evaporation, a plant with similar waste water
generation) and each has demonstrated a high degree of
engineering reliability. There are no process changes necessary
-------
for the implementation of the above technologies, although some
plants may have to segregate non-contact cooling waters from the
waste water streams and modify their boilers to accept hog fuel.
Cost of Application
The costs of obtaining the recommended effluent reductions set
forth herein for the model plant, are presented in Section VIII,
Cost, Energy, and Kon-Water Quality Aspects. The cost will vary
by choice of treatment system and in some cases the climatic
conditions occurring at the plant's location. The total yearly
costs range from $U,800 to $1U,000 with 9096 less than $10,000.
The capital investment costs range from $13,400 to $35,000 which
represents 0.16 to O.U2 percent of the $8.4 million cost of
constructing a new 270 metric ton/day (300 ton/day) plant.
Non-Water Quality Env i ronment al Impact
The non-water quality impact will result from the land disposal
of small amounts of sludge from certain alternatives. The
impact, however, will be insignificant because of the relatively
small quantities of solid material to be treated.
As presented in Section VIII the required energy for each
alternative treatment system will cause an increase of less than
1.1% in the electrical requirements of the model plant.
Factors to be Considered in Applying Effluent Limitations
As presented in Section V, Water Use and Waste Characteristics,
the model plant does not have a wet scrubber for air emission
control nor does it have a chip washer. Presently a minority of
existing plants have wet scrubbers in use and one plant is
reported to use a chip washer. The use of either of these
devices may result in an additional waste water source and thus
affect the costs of treatment.
-------
-------
SECTION X
BEST AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE
INTRODUCTION
The effluent limitations which must be achieved by July 1, 1983,
are to specify the degree of effluent reduction attainable
through the application of the best available technology
economically achievable. The best available technology
economically achievable is not based on an average of the best
performance within an industrial category, but is to be
determined by identifying the very best control and treatment
technology employed by a specific point source within the
industrial category, or subcategory, or the application of
different technology it is transferable from one industry to
another with a reasonable degree of confidence. A specific
finding must be made as to the availability of control measures
and practices to eliminate the discharge of pollutants, taking
into account the cost of such elimination.
Consideration must also be given to:
(a) the age of equipment and facilities involved;
(b) the process employed;
(c) the engineering aspects of the application of various
types of control techniques;
(d) process changes;
(e) cost of achieving the effluent reduction;
(f) non-water quality environmental impact (including
energy requirements).
In contrast to the best practicable control technology currently
available, the best economically achievable technology assesses
the availability in all cases of in-process controls as well as
additional treatment techniques employed at the end of a
production process.
Those plant processes and control technologies which at the pilot
plant, semi-works, or other levels, have demonstrated both
technological performances and economic viability at a level
sufficient to reasonably justify investing in such facilities may
be considered in determining the best available technology
economically achievable. The best available technology
economically achievable is the highest degree of technology that
has been achieved or has been demonstrated to be capable of being
applied to plant scale operation up to and including "no dis-
charge" of pollutants. Although economic factors are considered
in this development, the costs for this level of control are
intended to be the top-of-the-line of current technology subject
to limitations imposed by economic and engineering feasibility
-------
considerations. However, the best available technology
economically achievable may be characterized by some technical
risk with respect to performance and with respect to certainty of
costs. Therefore, the best available technology economically
achievable may necessitate some industrially sponsored
development work prior to its application.
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF BEST
AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE FOR THE WET STORAGE
SUBCATEGORY
Based on the information contained in Sections III through VIII
of this document, best available technology economically
achievable is the same as that identified as best practicable
control technology currently available in Section IX of this
report.
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF THE BEST
AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE EFFLUENT LIMITATIONS
GUIDELINES FOR THE LOG WASHING SUECATEGORY
The effluent limitation reflecting this technology is no
discharge of waste water pollutants navigable waters as developed
in Section IX.
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF THE BEST
AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE EFFLUENT LIMITATIONS
GUIDELINES FOR THE SAWMILL AND PLANING MILL SUBCATEGORY
The effluent limitation reflecting this technology is no
discharge of waste water pollutants navigable waters as developed
in Section IX.
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF THE BEST
AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE GUIDELINES FOR THE
FINISHING SUBCATEGORY
The effluent limitation reflecting this technology is no
discharge of process waste water pollutants to navigable waters
as developed in Section IX.
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF BEST
AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE FOR THE
PARTICLEBOARD SUBCATEGORY
The effluent limitation achievable by the application of best
available control technology economically achievable is no
discharge of pollutants as discussed in Section IX.
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF THE BEST
AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE FOR THE INSULATION
BOARD SUBCATEGORIES
-------
Based on the information contained in Sections III through VIII
of this document, a determination has been made that the effluent
limitation representing the degree of effluent reduction
attainable in the insulation board subcategories through the
application of the best available technology economically
achievable is a maximum discharge as follows:
30-Day Average
Subcategorv
I
II
Subcategorv
I
II
BODS
kg/kkq Ib/ton
0.38 0.75
1.13 2.35
BQD5 ___
Ib/ton
2.25
6.75
Total
Suspended Solids
kg/kkg Ib/ton
0.85 1.9
0.85 2.9
Daily Maximum
Total
Suspended Solids
kg/kkg
2.85
2.85
Ib/ton
5.70
5.70
6-9
6-9
-En-
s'9
6-9
Identification of the Best Available Technology Economically
Achievable
The best available technology economically achievable in the
insulation board industry is based on the treatment of all waste
water in a biological treatment system and recycling 70 percent
of the flow after mixed media filtration as described in section
VII. The remaining 30 percent of the flow is discharged with no
further treatment after the activated sludge system.
Engineering Aspects of Control Techniques Applicable
The technology summarized above is currently being utilized on an
experimental basis by two plants in subcategory I and one plant
in subcategory II. There is no information available on the
possible long term effects of reusing secondary effluent as
process makeup water; however, representatives of the insulation
board industry indicate that the reuse of a portion of the
secondary effluent from an activated sludge process is probably
feasible. The initiation of this technology will have to be
accomplished gradually to determine the effect on the production
process.
-------
Cost of Application
The cost of obtaining the recommended effluent reductions set
forth herein, for the model plants, are presented in Section
VIII, Cost, Energy, and Non-Water Quality Aspects and are
summarized below:
Subcategory
I
II
Total Invest-
ment Cost
$1,059,800
1,201,200-
1,266,500
Total
Yearly Cost
$318,200
378,300-
U07,900
% Capital
of New Plant
(12-6 million)
9.5-
10.0
Non-Water Quality Environmenta1 Impact The increase in energy
required for the implementation of this technology is presented
in detail in Section VIII. The energy required is electrical and
represents less than an 11 percent increase in the electricity
requirements of the model plants. As discussed in Section VIII
the non-water quality impact of this technology relates to the
land disposal of the solids removed from the waste water by
filtration. This is in addition to the waste solids resulting
from the activated sludge system as summarized in Section IX.
Factors to be considered in Applying Effluent Limitations
Operational limitations of the activated sludge process should be
considered in the application of the above effluent limitations.
These operational constraints are discussed under Section VIII
and summarized in Section IX. In addition, the technology
required to achieve the best available technology economically
achievable effluent limitations relies on the recycle of 70
percent of the effluent from an activated sludge system. It is
conceivable that all plants may not be able to recycle as much as
70 percent of the secondary effluent or, on the other hand, that
some plants may be able to recycle more than 70 percent. This
will be dependent on the individual plant's production process.
There are currently three plants in subcategory II achieving this
level of effluent reduction by the use of spray irrigation.
However, this technology cannot be utilized be every plant within
the industry as large areas of suitable land are required.
-------
SECTION XI
NEW SOURCE PERFORMANCE STANDARDS
INTRODUCTION
This level of technology is to be achieved by new sources. The
term "new source" is defined in the Act to mean "any source, the
construction of which is commenced after the publication of
proposed regulations prescribing a standard of performance." New
source technology shall be evaluated by adding to the
consideration underlying the identification of best available
technology economically achievable a determination of what high
er levels of pollution control are available through the use of
improved production processes and/or treatment techniques. In
addition to considering the best in-plant and end-of-process
control technology, identified in best available technology
economically achievable, new source technology is to be based on
an analysis of how the level of effluent may be reduced by
changing the production process itself. Alternative processes,
operating methods or other alternatives must be considered. How-
ever, the end result of the analysis will be to identify effluent
standards which reflect levels of control achievable through the
use of improved production processes (as well as control
technology), rather than prescribing a particular type of process
or technology which must be employed. A further determination
which must be made for new source technology is whether a
standard permitting no discharge of pollutants is practicable.
Specific factors to be considered in the determination of
standards of performance for new sources:
(a) the process employed and possible process changes;
(b) operating methods;
(c) batch as opposed to continuous operations;
(d) use of, alternative raw materials and mixes of raw
materials;
(e) use of dry rather than wet processes (including
substitution of recoverable solvents for water);
and
(f) recovery of pollutants as by-products.
NEW SOURCE PERFORMANCE STANDARDS - WET STORAGE SUBCATEGORY
Based on the information presented in Sections III through VIII,
new source performance standards for wet decking raw material
storage operations are this same as those identified in Section
IX, that is, best practicable control technology. The new
source performance standards for pond raw material storage
operations is no discharge of process waste water pollutants to
navigable waters.
'til
-------
RATIONALE
The storage of raw material in the timber products processing
industry usually occurs in out-of-doors situations. The volume
of waste water, i.e., water that comes in contact with the raw
material is, of course, dependent on the rate and duration of the
precipitation event (s) as well as the area of drainage into the
wet storage facility. While it is not possible to control the
precipitation volume, it is possible to control the area of
drainage to a wet storage facility, and to some degree the area
of the wet storage facility itself.
The proposed limitation of no discharge of process waste water
pollutants for pond storage operations is based on the following
considerations. Volumes of process waste water discharged from
ponds may be greater because they will usually be located in
depressions thus, drainage into the facility will be greater.
Materials present in the discharge from a pond may be more
concentrated with regard to dissolved materials because of the
leaching resulting from soaking. It is also acknowledged that
the current trend in the industry is away from pond storage of
raw material for among other reasons, the economic benefits that
timber products processors can realize from the more efficient
utilization of materials achievable in land based storage
operations.
NEW SOURCE PERFORMANCE STANDARDS - LOG WASHING SUBCATEGORY
Based on the information presented in Sections III through VIII,
the new source performance standards for the log washing
subcategory is no discharge of process waste water pollutants to
navigable waters.
NEW SOURCE PERFORMANCE STANDARDS - SAWMILLS AND PLANING MILLS
SUBCATEGORY
Based on the information presented in Sections III through VIII
the new source performance standards for the sawmills and planing
mills subcategory is no discharge of process waste water
pollutants to navigable waters.
NEW SOURCE PERFORMANCE STANDARDS - FINISHING SUBCATEGORY
Based on the information presented in sections III through VIII,
the new source performance standards for the finishing
subcategory is no discharge of process waste water pollutants to
navigable waters,
NEW SOURCE PERFORMANCE STANDARDS - PARTICLEBOARD SUBCATEGORY
Based on the information presented in Sections III through VIII,
the new source performance standards for the particleboard
subcategory is no discharge of process waste water pollutants to
navigable waters.
-------
NEW SOURCE PERFORMANCE STANDARDS - INSULATION BOARD MANUFACTURING
SUBCATEGORIES ~
Based on the information presented in Sections III through VIII,
new source performance standards for insulation board
manufacturing operations are the same as those identified in
Section IX:
Subcategorv
I
II
Subcategorv
I
II
RATIONALE
30-Dav Average
BODS
kg/kkg Ib/ton
1.25 2.50
3.75 7.50
BODS
kg/kkg Ib/ton
3.75 7.50
11.3 22.5
Total
Suspended Solids
Dailv Maximum
Total
Suspended Solids
kg/kkg
9.40
9.40
kg/kkg
3.13
3.13
Ib/ton
6.25
6.25
—
6-9
6-9
6-9
6-9
The best available technology economically achievable discussed
in Section X are based in part on the recycling of an estimated
70 percent of the process water after mixed media filtration.
This treatment and recycle technology is being evaluated on an
experimental basis. However, the degree of reliability has not
been proven sufficiently to merit inclusion in the consideration
of new source performance standards.
-------
-------
SECTION XII
ACKNOWLEDGEMENTS
This support document is based to a significant degree on a study
of the water pollution control aspects of the timber products
processing industry conducted by Environmental Science and
Engineering, Inc., Gainesville, Florida. Dr. Richard H. Jones
served as project director, John D. Crane was project manager.
Key staff members were Dr. Larry L. Olson, Leonard P. Levine,
John T. White and Jeffrey D. Einhouse.
Reynolds, Smith and Hills, Jacksonville, Florida, Dr. Frank D.
Schaumburg, Oregon State University, and Dr. Warren S. Thompson,
Mississippi State University provided assistance to the
contractor.
Appreciation is extended to the many groups and individuals from
the industry who worked with the Agency and the contractor to
provide and obtain information useful in the development of the
guidelines and standards presented here.
Appreciation is extended to the National Forest Products
Association, the National Particleboard Association, the
Acoustical and Insulating Materials Association, the Hardwood
Plywood Manufacturers Association, the Southern Hardwood Lumber
Manufacturers Association and the various industrial advisory
committees for their cooperation and assistance. Appreciation is
extended to numerous individuals within the industry who supplied
information and arranged on-site visits. Individuals who
particularly deserve recognition include C. Curtis Peterson,
Charles Morchauser, Bruce C. Grefrath, A. F. Trom, Tom Frost,
James Leker, William Ames, George Romeiser, Ted Merideth and
Robert Lunt.
Intra-agency review, analysis, and assistance was provided by the
Timber Products Processing Working Group/Steering Committee.
This group included the following EPA personnel:
Harold B. Goughlin, Effluent Guidelines
Division, Chairman
Irving Susel, Office of Planning
and Evaluation
G. William Frick, Office of Enforcement and
General Counsel
Arthur M. Mallon, Office of Research
and Development
Al Ewing, Office of Research and
Development
Technical guidance and direction was provided by Allen Cywin,
Director, Effluent Guidelines Division and Ernst Hall, Deputy
Director, Effluent Guidelines Division. D. Robert Quartel served
-------
as project officer during the contract phase of this effluent
guidelines development program.
Specific thanks are expressed to Nancy Fischer, Darlene Miller
and Linda Rose for their assistance in preparing this document
for publication.
-------
SECTION XIII
REFERENCES
1. Standard Industrial Classification Manual, U. S.
Government Printing Office (Stock No, 4101-0066) (1972).
2. The Story of Insulation Board, Acoustical and Insulating
Materials Association, Chicago, Illinois.
3. "Mat-Formed Wood Particleboard", U, S. Department
of Commerce, commercial Standard, CS236-66.
4. Wright, M.G., and Phelps, P.B., "Particleboard, Insulation
Board, and Hardboard: Industry Trends 1956-66", U.S.
Department of Agriculture (1967).
5. "The Story of Particleboard", National Particleboard
Association, Silver Spring, Md.
6- Current Industrial Reports: Particleboard 1959-1972, U.S.
Department of Commerce.
7. Fiberboard Industry and Trade, Defibrator AB Stockholm,
Sweden (November 1971).
8. "Report of the Presidents Advisory Panel on Timber and the
Environment" (April 1973).
9. Information provided by Environmental Protection Agency from
a study of Builders Paper and Board Industry.
10. Information provided by Environmental Protection Agency from
a study of The Pulp and Paper Industry.
11. Information collected during the Phase I Timber Products
Studies.
12. Meredith, T.H,, Southern Forest Products Association,
Personal Communication (November 1973).
13. The Outlook for Timber in the U. S. States, U.S. Department
of Agriculture, Forest Resource Report No. 20.
14. McHugh, R.A., Miller, L.S., and Olsen, T.E., The Ecology
and Naturalistic Control of Log Pond Mosquitoes in the
Pacific Northwest, Oregon State Board of Health, Division
of Sanitation and Engineering, Portland, Oregon.
15. Log Storage and Rafting in Public Waters, A task force study
by Pacific Northwest Pollution Control Council (August 1971),
16- 1973 Directory of the Forest Products Industries, 54th Edition.
-------
17. Standard Specifications for Insulating, American Society for
Testing and Materials, C208-72.
18. 1967 Census of Manufacturers, Bureau of the census, U. S.
Department of Commerce (July 1967).
19. Lambert, H-, "1971 Lumber Production", Forest Industries
99, (May 29, 1972).
20. Sweat's Catalogue, F. W. Dodge corporation.
21. Mobile Home Manufacturers Association, Personal
Communications (October 1973).
22. Grefrath, B.C., National Forest Products Association, Personal
Communications (November 1973).
23. Varossicau, W.W., Forest Products Research and Industries
in the U. S. States, J.M. Mevlenhoff, Amsterdam (1954),
24. Wood and Wood Products, Reference Data, Buying Guide (October
1967).
25. Eagle, S.V., Handbook of Adhesive Bonding, McGraw-Hill,
New York, N.Y. (1973).
26. Knapp, H.J., "Development, Principles, Problems and Techniques
of Finishing Particleboard," Proceedings, Washington State
University Symposium on Partic1eboard, No. 2 (1968).
27. Batey, T.E., Prefinishing and Surfacing of Softwood Plywood,
FAO/PPP Cons./Paper 3,8.
28. "Plywood and Other Wood-Based Panels", Food and Agricultural
Organization of the U. S. Nations, Rome (1966).
29. Tomsu, M.L., "Wood Finishes", Canadian Paint and Finishing;
Modern Finishing Methods, ££, 6A (June 1973) .
30. Gluk, D.G., "Selection and Field Testing of Coatings for
Exterior Hardboard Products", Forest Products Journal, 21,
9 (November 1971).
31. McDonald, C.E., Hardwood Plywood Manufacturing in the U.S.A.,
FAO/PPP cons,/Paper 3.22.
32. Bryant, B.S., Film Finishes for Plywood, FAO/PPP Cons./Paper 3.4.
33. Brumbaugh, J.I., "Overlaying of Particleboard", Proceedings,
Washington State University Symposium on Particleboard, No. 1
(1967),
34. MacDonald, R.G., Editor; "Pulp and Paper Manufacture", The
Pulping of Wood, _1, Second Edition (1969) .
-------
35. Runckel, W.J., "C-E Bauer Pressurized Double-Dies Refining
Systems-Application and Development in the Board Field",
Proceedings of Seventh Symposium on Particleboard (March 1973).
36. surdyk, L.V,, "The Pallman Flaker", Proceedings of First
Symposium on Particleboard, Washington State University
(March 1967).
37. Binder, K.A*, "Resin Application and Quality in Particle
board Manufacture," proceedings of First Particleboard
Symposium. Washington State University (March 1967) .
38. Heebink, E.G., "Wax in Particleboards", Proceedings of
First Particleboard Symposium. Washington State University
(March 1967).
39. Newman, W.M,, "Principles of Mat Formation," Proceedings of
First Particleboard Symposium, Washington State University
(March 1967).
40. Mitlin, L., Particleboard Manufacture and Its Application,
Seven Oaks (Kent), Press Media, LTD (1969).
i*1. Graham, J.L., Graduate Student; Schaumburg, F.D., Assistant
Professor, Department of Civil Engineering, Oregon State
University, Pollutants Leached from Selected Species of
Wood in Log Storage waters, presented at 24th, Purdue
Industrial Waste Conference, Lafayette, Indiana (May 6, 1969).
42. Graham, J.L., Pollutants Leached From Selected Species of
Wood in Log Storage Waters. An abstract of the thesis for
Master of science Degree, Department of Civil Engineering,
Oregon State University, Corvallis, Oregon.
43. Williamson, K.J., "A Study of the Quantity and Distribution
of Bark Debris Resulting from Log Rafting", M.A. Thesis (1969).
44. Schaumburg, F.D., "The Influence of Log Handling on Water
Quality", 1969-70 Annual Report for Research Project WP
01320-01, Department of Civil Engineering, Oregon State
University (March 1970).
45. Hoffbuhr, J. W., The Character and Biological Treatabilitv
of Log Pond Waters, a thesis for the Master of Science Degree
in Civil Engineering, submitted to Oregon State University
(June 1970) .
46. Benedict, A.H., "An Investigation of the Effects of Bark
Leaching and Benthal Decomposition on Receiving Water Quality",
National Council of the Paper Industry for Air and Stream
Improvement, Inc., Technical Bulletin No. 247
(August 1971) .
47. Asano, T., Department of Civil Engineering and Engineering
Mechanics, Montana State University; Towlerton, A.L., Sanitary
-------
Engineering, Cornell, Rowland, Hayes and Merryfield - Clair A.
Hill and Associates, Portland, Oregon: "Leaching of Pollutants
from Wood chips in the simulated Hydraulic Pipelines" (June 25,
1973).
48. Sproul, O.J., Sharpe, C.A., "Water Quality Degradation by wood
Bark Pollutants", Water Resources Center Publications, No. 5
(June 1968) .
49. Schaumburg, F.D., The Influence of Log Handling on Water
Quality, Office of Research and Monitoring, U.S. Environmental
Protection Agency, Washington, D.C. (1973).
50. Bollen, W.B., "Properties of Tree Barks in Relation to Their
Agricultural Utilization".
51. Hajny, B.J., Research Chemist, Outside Storage and Pulpwood
Chips (October 1973).
52. Asano, T., Towlerton, Laboratory study from "Leaching of Pollutants
From Wood Chips in the Simulated Hydraulic Pipelines" (June 1973).
53. Industry Advisory Committee Meeting, October 1-3, 1973, held at
the Delta Towers Hotel, New Orleans, Louisiana.
54. Gran, G., Waste water From Fiberboard Mills. Stockholm, Sweden.
55. "Effluent Limitations Guidelines", Acoustical and Insulating
Materials Association, Park Ridge, 111. (November 15, 1973).
56. Leary, P.E., "Finishing Wood", Canadian Paint and Finishing;
Modern Finishing Methods, £7, No. 6A (June 1973).
57. Conor, R., National Paint and Coating Association, Personal
Communication (November 19, 1973) .
58. Barret, W.J., Morneau, G.A., Roden, J.T., III, Waterborne Wastes
of the Paint and Inorganic Pigments Industries, Southern Research
Institute, Birmingham, Alabama (July 1973).
59. "Policy on subsurface Emplacement of Fluids by Well Injection",
A bolicy statement issued by the U.S.E.P.A. with
"Recommended Data Requirements for Environmental Evaluation
of Subsurface Emplacement of Fluids be Well Injection,"
Washington, D.C. (February 1973).
60. "Particles Strained From Log Pond Before Water Enters Stream
flow". Forest Industries, 96 (November 1972).
61. "Settling Ponds Clean Waste Water at Mill Complex", Forest
Industries, 99 (November 1972).
62. Blanton, B.I., Jr., The Characterization and Physical Chemical
Treatabilitv of Log Pond Waters, a thesis for the Master of
Science Degree in Civil Engineering, Oregon State
1+20
-------
University (August 1969).
63. Wilson, T.E., and Wang, M. H., "Removal of Liquid by Foam
Separation Processes", 25th Purdue industrial Wastes Conference
(May 1970).
6U, Metcalf and Eddy, Inc., Waste Water Engineering: Collection,
Treatment. Disposal, McGraw-Hill Book Company (1972).
65. Bailey, G.S., "Weyerhaueser Treatment of Pulp and Paper Wastes
at the Plymouth, North Carolina Complex," 24th Purdue Industrial
Wastes Conference (May 1971).
66. Timpany, P.L., et._ al. "Cold Weather Operations in Aerated Lagoons
Treating Pulp and Paper Mill Wastes", 2.6th Purdue Industrial
Wastes Conference (May 1971). ~
67. Bodien, D.G., Plywood Plant Glue Wastes Disposal, F.W.P.C.A.
(March 1969).
68. Bishop, D.F., et al., "Studies on Activated Carbon Treatment",
Journal Water Pollution Control Federation, 39, 2 (1967).
69. Beebe, R.L., and Stevens, J.I., "Activated Carbon System
for Waste Water Renovation", Water and wastes Engineering
(January 1967).
70. Smith, S.E., and Christman, T.F., "Coagulation of Pulping
Wastes for the Removal of Color" Journal, Water Pollution Control
Federation, 41, 2, Part I (1969).
71, Moggio, W.A., "Experimental Chemical Treatments For Kraft
Mill Wastes", National Council of tfie Paper Industry for Air
and Stream Improvement. Inc-, Technical Bulletin No. 50 (1952).
72. McGlasson, W.G., et.al., "Treatment of pulp Mill Effluents
With Activated Carbon", National Council of the Paper Industry
for Air and Stream Improvement, Inc., Technical Bulletin No. 199
(1967).
73. Gellman, E., "Aerated Stabilization Basin Treatment of Mill
Effluents", National Council of the Paper Industry for Air
and Stream Improvement, Inc., Technical Bulletin No. 185 (1965).
74. Voights, D-, "Lagooning and Spray Disposal of NSSC Pulp
Mill Liquors", Purdue University Industrial Waste Conference
X (1955).
75. Timpe, W.G., Lang, E., and Miller, R.L., Kraft Pulping Effluent
Treatment and Reuse - State of the Art, Environmental Protection
Technology~series EPA-R2-73-164 (1973).
76. Follett, R., and Gehm, H.W., "Manual of Practice for Sludge
Handling in the Pulp and Paper Industry", National Council
of the Paper Industry for Air and Stream Improvement, Inc.,
-------
Technical Bulletin No. 190 (1966).
77. Gehm, H.W., State-of-the-Art Review of Pulp and Paper Waste
Treatment. EPA Contract No. 68-01-0012 (April 1973).
78. Oilman, E.S., Handbook of Applied Hydrology, Chapters 9, 10,
and 11, McGraw-Hill (1964).
79. McKee, J.C,, and Daniel, J.W., "Long Term Storage of Pulpwood
in Sealed Enclosures", Tappi, 49, 5 (May 1966).
80. Baker, N., "Disposal of Timber Laminating Glue Wastes" (February
24, 1966).
81. Haskell, H.H., "Handling Phenolic Resin Adhesive Washwater
in Southern Pine Plywood Plants", Forest Products Journal
21, No. 9 (September 1971),
82. Baker, N., Borden Chemical Company, Personal Communications is
(September-December 1973).
83. Buckley, D.B., and McKeown, J.J., An Analysis of the Performance
of Activated Sludge and Aerated Stabilization Basin Systems
in Controlling the Release of Suspended Solids in Treated
Mill Effluents to Receiving Waters, National Council of the
Paper Industry for Air and Stream Improvement, Inc. (1973).
84. Eckenfelder, W.W., Industrial Water Pollution Control, McGraw-
Hill, N.y. (1966).
85. "Mill Estimates Saving of 3/m in its Switch to Dry Decking",
Forest Industries, 97 (April 1970).
86. Schaumburg, F.E., An Analysis gf the Log Storage Situation
At Columbia Plywood Corporation. unpublished work cited by
permission of author (1973).
87. Back, E.L., and Larsson, S.A., "Increased Pulp Yield As a Means
of Reducing the BOD of Hardwood Mill Effluent", Swedish
Forest Products Research Laboratory.
88. Reduction of Pollution From Wet Process Fiber Board Production,
Defibrator Stockholm, Sweden, "Lesdrevmash-73", September
5-19, 1973, Moscow, USSR.
Refining and Water Pollution Consequences, Swedish Forest Products
Research Laboratory.
90. Peterson, C., Acoustical and Insulating Materials Association,
Personal communication (December 19, 1973).
91. Morchauser, C., National Particleboard Association, Personal
Communication (December 18, 1973) .
422
-------
ADDITIONAL REFERENCES
Asplund, A.e Trends and Developments In the Manufacture Of Fiberboards,
presented at the Seventh World Forestry Congress (October 1972).
Berrong, H.B., "New Wax Sizing Agents For Particleboard", Forest
Industries (September 1973).
Blase, F.G., Characteristics Of Pulp and Paper Mill Sludges, Thesis,
School of Forestry, University of Washington (1970).
Burns, O.B., Jr., and Mancini, H.L., A Sludge Disposal System For
Mixed Primary and Secondary Sludges At the Covington Virginia Bleached
Kraft Mill (April 1966).
Degroot, R.C-, and Scheld, H,W, f "Biodegradability of Sapwood From
Southern Pine Logs Stored Under A Continuous Water Spray", Forest
Products Journal, 21, 1, (October 1971).
"Combined Treatment of Municipal Kraft Linerboard and Fiberboard
Manufacturing Wastes", U.S.E.P.A., Industrial Pollution control
Program no. 11060DPD (February 1971),
Ellwood, E.L. and Ecklund, B.A., "Bacterial Attack Of Pine Logs In
Pond Stoarge", Forest Products Journal, IX, (9) (September 1959).
"Effect of Bark Content On BOD and Solids Content of Pulping
Effluent", Project *2433, Institute of Paper Chemistry, Appleton,
Wisconsin (January 17, 1964).
"Effect of Steam Pressure on BOD and solids Content of Pulping
Effluent", Project #2433, Institute of Paper Chemistry, Appleton,
Wisconsin (November 5, 1963) .
Emand, R., "Mill Uses Electricity Heated Water TO Thaw Frozen Logs
In Its Pond", Forest Industries. 99 (June 1972).
Giordano, E.E., "Dozer Boat Tugs, A Hillside Railway, and Log Stackers
Solved The BCFP Dilemma: How To Get Lake Williston Logs To The Mackenzie
Mines", British Columbia Lumberman (March 1972),
Grah, E., "Log Losses Average 24 Million Cu.Ft."-"...But The Rest
Piles Up As Debris", British Columbia Lumberman (March 1972).
Grah, E., "Log Losses Average 24 Million Cu.Ft."-"Salvors Recover
Some Six Million...", British Columbia Lumberman (March 1972).
Gran, G., "waste water From Fiberboard Mills", internation Union Of
Pure And Applied Chemistry, 29 (1972).
"Hardwood Fractions Molded In Four-Press-Line System", Forest Industries
(June 1963).
Hedborg, L., "Water Supply and the Treatment Of Waste Effluent
From Wallboard Manufacturing Operations", FAO/ECE/BOARD CONS/ PAPER 4,F.
-------
Hutto, F.B., Jr., "Diatomite Filtration in a Board Mill", based on paper
presented at the 1968 Purdue Industrial Wastes Conference.
Industrial Waste Guide On Logging Practices, U.S. Department of the
Interior (February 1970). ~
"An Investigation Of Certain Water Quality And Biological Conditions
In Boise Creek - Enumclaw, Washington", Washington Pollution Control
Commission, Research Bulletin 63 (March 1973).
Keeley, M., "The Spring River Round-Up", British Columbia Lumberman
(March 1972).
Knox, L.C. and Schmitz-LeHanne, A., "Development, Manufacture Described
Of Thin Dry Fiberboard Product", Forest Industries (July 1973).
Knuth, D.T., and McCoy, E., "Bacterial Deterioration Of Pine Logs In
Pond Storage", Forest Products Journal, 12 (September 1962).
Kurth, E.F. and Hubbard, J.K., "Extractives From Pondersa Pine Bark",
Ind., and Eng- Chem, £3 (1951) .
Lambert, H., "Board Industry Registered Major Gains in 1972", Forest
Industries (July 1973) .
"Log Bundles Winched From Lake", Forest Industries. 99 (November 1972).
MacPeak, M.D., Bacterial Deterioration As Related To Locf Storage
Practices (January 25, 1963).
Malo, B.A., "Semichemical Hardwood Pulping and Effluent Treatment:,
Journal Water Pollution Control Federation, 39, no.11 (1967).
Maloney, T.M., Proceedings-One Through Seven - Symposium On Particleboard
Wood Tech, Section - Engineering Research Division and Tech. Extension
Service, Pullman, Washington.
Marston, R.B. and Poston, R.F., "By-Product Utilization: A Positive
Approach To Pollution Control", Journal of Forestry, 68, no. 5
(May 1970).
"Materials Handling Concept Behind Eurocan's Lumber Transportation
Over Coastal Range", British Columbia Lumberman (March 1973) .
Miller, D.J., "Molding Characteristics of Some Mixtures of Douglas
Fir Bark and Phenolic Resin", Forest Product Journal, 22, no. 9
(September 1972).
Nepper, A.C., "Biological Treatment Of Strong Industrial Waste From A
Fiberboard Factory", Proceedings of the 22nd Industrial Waste Conference
(May 2-4, 1967).
Parmelee, D.M., Trends In The Disposal of Biodegradable Waste Water
An Upcoming Problem-A Possible Solution, presented before the American
-------
Hardboard Association Meeting (May 23, 1967),
Parsons, N.C., "Spray Irrigation of Wastes From the Manufacture of
Hardboard", Proceedings 22nd Purdue Industrial Waste conference.
Parsons, W.c. and Woodruff, P.H., "Pollution Control: Water Conservation,
Recovery, and Treatment", TAPPI, 53, no. 3 (March 1970).
Pease, D.A., "Plywood Scrap Converted Into Useful Product", Forest
Industries (March 1972).
Philipp, A.H,, "Disposal of Insulation Board Mill Effluent By Land
Irrigation", Journal Water Pollution Control Federation, 43, (no. 8)
(August 1971).
"Principal Pollution Problems Facing The Solid Wood Products Industry",
Forest Products Journal, 21, no. 9 (September 1971).
Pulikowski, Zdislaw, "Development Tendencies In The Fiberboard Industry",
Holstechnologie, 5, no.2 (1964).
Quirk, T.P., "Aerated Stabilization Basin Treatment of White Water",
Industrial Water and Wastes Engineering (1969).
"7,000 Foot Ice Bridge Spans Lake Williston In Winter Log Transportation",
British Columbia Lumberman (March 1973).
Sohlman, L., Measures Taken By The Wallboard Mill of Skinnskatteburg
To Control Water Pollution.
Stiehler, M.M., A Comparison Of Two Pulp and Paper Mill Sludges Used
In Rigid Insulation Board, University of Washington (1971).
Stiehler, A.M., The Technical Feasibility of Utilizing Papermi11 Sludges
in Insulation Board. Water Quality and The Forest Products Industry
(May 1971) .
Stout, A.W., Log Storage Practices (September 1, 1957).
Stout, A.W., The Protection Of Stored Logs (September 1, 1952).
Stout, A.W., Storage Caused Defects In Idaho White Pine Logs
(February 1, 1955).
Stout, A.W., The Storage Of Ponderosa Pine and Sugar Pine Logs
(June 3, 1955).
Stout, A.W., Water Sprinkling Protects Decked Logs (August 5, 1955,
revised August 5, 1957).
"Too Mulch, Too Soon", Wood and Wood Products, 77 no. 2
(February 1972).
-------
-------
SECTION XIV
GLOSSARY
Acrylic Resin - A synthetic, thermoplastic resin formed by
polymerizing esters of acrylic acid and methacrylic acid.
"Act" - The Federal Water Pollution Control
1972.
Act Amendment s of
Activated Sludge Process - A biological waste water treatment
process in which a mixture of waste water and activated sludge is
agitated and aerated. The activated sludge is subsequently
separated from the treated waste water (mixed liquor) by
sedimentation and wasted or returned to the process as needed.
Additive - 1) In board production, any material introduced prior
to the final consolidation of a board to improve some property of
the final board or to achieve a desired effect in combination
with another additive. Additives include binders and other
materials. Sometimes a specific additive may perform more than
one function. Fillers and preservatives are included under this
term. 2) In liquid coatings used in:finishing operations, an
additive may be any material added to the coating material in its
formulation, usually to prevent undesirable effects during its
shelf life. Mercuric additives commonly found in paint and
coating materials prevent biological contamination during the
shelf life of the material.
Aerated Lagoon - A waste water treatment pond in which mechanical
or diffused-air aeration is used to supplement the oxygen supply.
Aerobic - A condition in which free, elemental oxygen is present.
Air Classifier - A cylindrical chamber in which small and large
wood particles are separated by the introduction of an air
stream.
Air Seasoning - See Lumber Drying.
Air Separation - The unit operation associated with the air
classification of wood particles by particle size.
Alkyl Resin - A synthetic, thermoplastic resin used in paints,
varnishes and lacquers produced by the reaction of a polybasic
acid, such as phthalic, maleic or succinic acid, with a
polyhydric alcohol such as glycerine.
Anaerobic - A condition in which free elemental oxygen is absent.
Attrition Mill - Machine which produces wood fibers by forcing
coarse material, shavings, or pieces of wood between a stationary
and a rotating disc fitted with slotted or grooved segments.
427
-------
Autocatalvsis - The catalysis of a reaction by one of its
products.
Bagasse - The solid matter remaining after extraction of liquids
from sugar cane.
Band Saw - A saw in the form of an endless belt running over
wheels.
Barker - Machines which remove bark from logs. Barkers may be
wet or dry, depending on whether or not water is used in the
operation. There are several types of debarkers including drum
barkers, ring barkers, bag barkers, hydraulic barkers, and
cutterhead barkers. With the exception of the hydraulic barker,
all use abrasion or scraping actions to remove bark. Hydraulic
barkers utilize high pressure streams of water.
Bark Mulch - A material used for soil conditioning purposes pro-
duced by hogging bark into fine particle size and possibly adding
nitrogen in the form of liquid ammonia by spraying.
Barrel Staves - Narrow strips of wood placed edge to edge to form
the sides, covering, or lining of a barrel.
Base Coating - See Ground coating.
Blender - A machine used to blend wood particles and additives in
the production of particleboard. Blenders are of two types: 1)
A continuous type consists of a horizontal trough with mixing
arms and sprayers. Wood particles are fed into the trough while
additives are blended in by means of spray nozzles. 2) A batch
type consists of a mixing tank with agitation in which the
particles and additives are blended.
Blue Stain - A stain imparting a blue color to the wood. This
stain is caused by a fungus. The growth of this fungi is
retarded by water storage or water spray of the logs.
BOD (biochemical oxygen demand) - is a measure of biological
decomposition of organic matter in a water sample. It is
determined by measuring the oxygen required by microorganisms to
oxidize the organic contaminants of a water sample under standard
laboratory conditions. The standard conditions include
incubation for five days at 20 C.
BOD7 - A modification of the BOD test in which incubation is
maintained for seven days instead of five. This is the standard
test in Sweden.
Box Cleat - In the production of wood containers, a small strip
of wood fastened perpendicular to the sides to lend lateral
support.
Broke System - A system for repulping and reuse of wasted or
rejected product to form new croduct.
-------
Cambium Layer - A thin formative layer between the xylem and
phloem of most vascular plants that give rise to new cells and is
responsible for secondary growth.
Cant - The remaining portion of a log, either square or
rectangular in cross section; after the outside edges or slabs
have been sawn or chipped off.
Carriage - see Log Carriage.
Casehardening - A condition of stress and set in wood in which
the outer fibers are under compression stress and the inner
fibers are under tensile stress, the stress persisting when the
wood is uniformly dry throughout.
Casein Resin Glue - A glue commonly used in wood fabricating,
made from a derivative of skimmed milk.
Catalyst - An acid or acid salt used to promote quick curing of
resins. common catalysts are ammonium hydroxide, ammonium
chloride, and ammonium sulfate.
Caul - A metal plate or screen on which a formed mat of particles
or fiber is placed for transfer to the press, and on which the
mat rests during the pressing process.
Cellulose - A complex polymeric carbohydrate, C6H10O5_, yielding
only glucose on complete hydrolysis, which constitutes the chief
part of the cell walls of plants.
Chipping Headrig - Equipment consisting of chipping saws which
chip away non-marketable lumber, so that subsequent sawing
operations will result in marketable lumber.
Chipper Saw - A saw used to face the side of logs prior to being
sawn.
Clarifier - A unit of which the primary purpose is to reduce the
amount of suspended matter in a liquid.
Coagulation - The process of becoming viscous or thickened into a
coherent mass.
CQp (Chemical Oxygen Demand) - A test procedure to give a measure
of the oxygen demand equivalent to that portion of matter in a
sample which is susceptible to oxidation by a strong chemical
oxidant.
Cold Setting - In resin curing, the setting of resins which
requires no heat as compared to heat curing.
containment Pond - See Lagoon.
Cord - A unit of wood equal to a stack 1,22 m by 1.22 m by 2.U4 m
or 3.625 cu m (four ft by four ft by eight ft or 128 cu ft).
-------
Core Stock - Supply of coarse particles used in the fabrication
of the inner core of particleboard.
Correlation Coefficient - A numerical value expressing the degree
of association between two variables.
Cross Banding - The transverse reinforcement of panels by wooden
strips which are weaker in one direction than in the other, i.e.,
extruded particleboard.
Curtain Coating - A method used in applying liquid finishing
materials usually to flat substrate surfaces. The curtain
coating equipment produces a thin, uniform, curtain-like film of
liquid material which falls by gravity to the panel substrate as
it passes through the coating zone.
Debarker - See Barker.
Debarking - The removal of bark from logs.
Deck - A stack of logs.
Decker - A machine consisting of a wire-covered cylinder, usually
with an internal vacuum, over which the suspension of fibers in
water is passed in order to clean the pulp and to increase the
consistency.
Defibrator - A type of disc-refiner.
Diatomaceous Earth Filter - A type of filter in which
diatomaceous earth, a light, friable, siliceous material, is
applied to an existing surface prior to filtration.
Dimension Lumber - Lumber sawn to specified dimensions.
Direct Roll Coating - A method used in applying liquid finishing
materials to flat substrate surfaces. The equipment consists of
an applicator roll which applies the liquid material to the
substrate surface, a metering roll which controls the thickness
of the liquid material on the applicator roll, and feed and
support rolls which feed the panel substrate through the coating
device and provide support for the panel against the applicator
roll.
Door Skin - The outer wood sheet of a frame-type door.
Double Band Headrig - A pair of band saws used to accomplish
initial log breakdown.
Dressed Lumber - Lumber which, not to be marketed as "green"
lumber, is further processed by drying and planing. Other
treatments such as chemical preservative treatment and end
coating are generally applied.
Dry Decking - See Log Storage.
-------
Dust Log - A product produced by injecting sawdust into a mold
under heat and pressure without chemical binders.
Dyes - Synthetic or natural organic chemicals that are usually
soluble in solvents characterized by good transparency and low
specific gravity.
Edge Jointing - See Jointing.
Edger - A stationary circular saw that can be laterally adjusted
to rip desired widths of lumber.
Edging - The process of producing specified widths of boards,
after a log is reduced into desired thickness.
Embossing - The raising in relief of a surface to produce a
design.
End Checking - Cracks which form in logs or lumber because of
rapid drying out of the ends.
End Coating - The application of paraffin or other wax emulsion
to lumber ends in order to retard end checking.
End Jointing - See Jointing.
Epoxv Resin - By-product of the petroleum industry, commercially
produced by a reaction between Bisphenol A, made from phenol and
acetone, and Epichlorohydrin, a by-product in the manufacture of
synthetic glycerine.
Estuarine Waters -,An inland arm of an ocean or the lower end of
a river which empties into an ocean; mixtures of fresh and saline
waters.
Excelsior - Fine curled wood shavings used especially for packing
fragile items.
Extruded Particleboard - A particleboard manufactured by forcing
a mass of particles and binder through a heated die with the
applied pressure parallel to the faces and in the direction of
extruding.
Extruder Applicator - An applicator which applies glue by means
of a ribbon to one surface of a board.
Fabricating - The jointing of pieces of wood by mechanical means
or adhesives.
Face Stock - Fine particles used in fabrication of the outer
layer or the face of particleboard.
Feedworks - Machinery associated with the feeding of logs to the
head saw.
«*31
-------
Fiber Preparation - The reduction of wood to fiber or pulp,
utilizing mechanical, thermal or chemical methods.
Filler - A liquid finishing material, usually containing
considerable quantities of pigment, used to build up or fill
depressions and imperfections in the surface of the wood
substrate.
Finger Joint - A joint produced by machining lumber ends to form
interlocking finger-like protrusions.
Finishing - Consists of surface smoothing such as sanding or
planing, covering with liquid coatings or covering with various
sheet materials or combinations of these operations.
Flaker - A particle formation machine which produces mainly core
stock and some face stock for particleboard fabrication. This
machine utilizes a series of knives to reduce roundwood and
residues to desirable particle sizes.
Flotation Clarifier - A device facilitating solids separation by
causing the solids to float to the surface by the aeration of the
waste water.
Fluidization of chips - The process of suspending chips in
for hydraulic transfer.
water
Fluidized Bed Principle - A principle which produces the
equalization of gravity on a particle bed by an influent
pressurized gas or liquid. Intraparticle friction causes a
pressure drop resulting in the suspension of the particles.
Flush Door - A door manufactured by covering a wooden frame
a skin.
with
Forming Machine - A device used to form a mat or fiber or
particles.
Fourdrinier Machine - A type of forming machine which utilizes
the gravity dewatering of stock through a wire screen.
Fractionated Wood - Wood chips, sawdust, planer shavings, etc.,
derived from roundwood or residual wood. Fractionated wood may
be a raw material of some process as in the production of
particleboard or a waste product of other operations such as
sawmilling.
Furnish - The material used for mill production.
Furniture Stock - Lumber to be used in furniture manufacture.
Saw - A saw which consists of an array of parallel blades
mounted in a frame which moves up and down as a log is entered.
«i32
-------
Gluing - In fabricating operations, the application of glue
lumber by a double roll spreader or extruder applicator.
to
Grain Printing - The process of printing a natural wood grain
pattern onto the surface of a wood-based product by roll or flat-
plate printing using a colored ink or paint to produce an
imitation wood grain effect of the surface of the prefinished
product.
Green Chain - A handling system for handling green lumber.
Green lumber - Unseasoned wood.
Ground Coating - The cost of colored material, usually opaque,
applied before the grain printing ink, in producing imitation
wood grain effects for various prefinished wood-based products.
Often referred to as base coating.
Groundwood - A fibrous material produced by the stone-grinding of
round wood under a shower of water.
Hammermill - A type of particle preparation device which utilizes
a mechanical array of steel arms or hammers to flagellate large
wood chips into smaller pieces.
Hardboard - A compressed fiberboard of 0.50 to 1.20 g/cu m (31 to
70 Ib/cu ft) density. Alternative term: fibrous-felted
hardboard.
Hardwood - wood from deciduous or broad leaf trees. Hardwoods
include oak, walnut, lavant elm, cherry, hickory, pecan, maple,
birch, gum, cativo, teak, rosewood and mahogany.
Headrig - All machinery utilized to produce the initial breakdown
of a log into boards, dimensions or cants.
Headsaw - A single diesel or electric powered saw which breaks
down logs into boards.
Heat Curing - The curing of resins by direct heat.
Heat Exchanger - A device which allows the transfer of heat from
one media to another.
Hemicellulose - One of a number of substances resembling, but
having simpler structures than that of cellulose, and sometimes
resulting from the partial hydrolysis of cellulose. The term
hemicellulose is also applied to certain constituents of starch,
and of the cells of animals.
High-density Overlay - A phenolic resin-impregnated paper most
commonly used to overlay softwood plywood panels. Resin content
is usually about 45 to 55 percent and the overlay is self-
bonding.
1*33
-------
Hog Chipper - A device used for reducing the size of particles.
Hog Fuel - Fractionalized wood used to fire a boiler.
Hogged Bark - Bark reduced to a uniform size by passing through
an attrition device,
Hot Press - Particleboard mat presses are of three types:
1) Multi-opening hydraulic - consists of 20 to 30 shelves with
individual platens which close simultaneously. 2) Single
opening hydraulic - mechanically similar to multi-opening; in
place of numerous shelves, one long shelf. 3) Continuous
roller type press receives mats in continuous ribbon. Boards are
cut to required lengths.
Hydraulic Debarker - See barker.
Hydraulic Press - See Hot Press.
Hydrocarbon - An organic compound containing only carbon and
hydrogen and often occurring in petroleum, natural gas, coal and
bitumens.
Hydrolysis - A chemical process of decomposition involving
splitting of a bond and addition of the elements of water.
Insulation Board - A dried mat of interfelted fibrous material.
Jointing - An operation employed to join two or more pieces of
wood in fabricated wood products. Depending on product
requirements, joints are of three basic types: edge jointing or
side-to-side-grain joints, end to-side-grain joints, and end
jointing or end-to-end-grain joints. In all joints the
application of adhesives and the subsequent curing process are
performed.
Kerf Loss - In a saw mill, the volume of wood lost to sawdust.
Kiln Drying - See Lumber Drying.
Kjld-N - Kjeldahl Nitrogen - Total organic nitrogen plus
of a sample.
ammonia
Knife Coating - A method used in applying liquid finishing
materials, usually of high viscosity, to flat substrate surfaces.
The equipment consists basically of a direct roll coater which
applies a heavy deposit of liquid material onto the substrate
surface. Doctor blades then wipe off the excess material,
filling the low spots and pores.
Kraft Paper - A paper of high strength made of sulfate pulp. The
paper is commonly impregnated with various resins to be overlaid
onto softwood plywood.
«*3
-------
Lacquer - A thin-bodied, quick-drying coating material,
consisting of a mixture of solutions of nitrocellulose, ethyl-
cellulose and natural and synthetic resins which form a hard film
upon drying by evaporation alone.
Lagoon - A pond containing raw or partially treated waste water
in which aerobic or anaerobic stabilization occurs.
Laminated Beam - A structural member in which two or more pieces
of lumber are joined together face to face usually employing an
adhesive.
Laminated Decking
A fabricated wood product which is
manufactured by the use of side-to-side-grain joints.
Land Decking - See Log Storage.
Land Spreading - The disposal of process waste water by spreading
it on land to achieve degradation by soil bacteria.
Leaching - Mass transfer of chemicals to water from wood
materials which are in contact with it.
Lignin - An amorphous polymeric substance related to cellulose
that together with cellulose forms the woody cell walls of plants
and the bonding material between them.
Linear Regression Analysis - A statistical technique for defining
the equation of best fit for two variables.
Log Carriage - A platform on wheels which holds a log in place
and, in running parallel to the saw, feeds the log to be cut.
Log Driving - The manned operation of driving or "herding" logs
from one point to another on moving waters.
J&3. Flume - An open channel of water used to feed logs to mills.
£23 Gang Mill - See Gang Saw.
Log Pond - See Log Storing.
Log Raft - An aggregation of floating logs, loose or bundles,
contained by perimeter logs.
Log storing - Retaining large inventories of logs to maintain a
supply. The four common types of log storing facilities are:
-------
1) Dry-decks - logs stacked on land or land-decked
2) Wet-decks - land-decked logs sprinkled with water to
minimize end-checking
3) Log Pond - usually long-term storage of logs by
floating them on a body of water
4) Mill Pond - usually short-term storage of logs by
floating them on a body of water located at the
mill site,
Log Washing - A prebarking process which is carried out by means
of sprayers as logs are transported to mill or through storage in
log ponds.
Lumber Drying - The process in which lumber is dried by one of
two methods:
1) Air seasoning - boards are segregated according to
board weight, coated with chemical preservatives
and stacked in a manner that will provide
sufficient air circulation.
2) Kiln drying - a process whereby green or pre-air
seasoned boards are dried in a kiln which is a
humidity and temperature controlled building.
Lumber Surfacing (Planing) - A finishing process which is carried
out by means of surfacing tools, i.e., planer knives that are
attached to a rotating cutterhead.
Machining - One of the several unit operations employed in the
timber products industry to produce a desired shape or form for a
particular wood product.
Mastic Construction Adhesives - Adhesives consisting of a thick
dispersion of various elastomers in an organic solvent, used for
example, in adhering panels to frames or plywood to floor joists.
Mat Formation - Part of the manufacturing process of insulation
board, particleboard and hardboard, in which fractionated wood or
fibers are arranged in a rectangular solid configuration prior to
pressing or drying operations.
Mechanical Refining - See Refiner.
Medium-density Overlay - A phenolic resin-impregnated paper, most
commonly used to overlay softwood plywood panels. Resin content
is usually about 20 to 25 percent and the overlay is not self-
bonding.
Melamine Resin - A synthetic, thermosetting resin made from
melamine and formaldehyde, which cures quickly at relatively low
temperatures, and is characterized by high heat resistance and
stability of color.
Melamine-formaldehyde Resin - See Melamine Resin.
we
-------
Melamine-Urea - A mixture of melamine and urea resins.
Metering Bin - A pre-particle formation apparatus which ensures
the homogeneity of wood pieces in order to provide uniformity of
feed flow.
Middle Lamella - A protoplasmic layer in wood which separates
individual cells.
Mill Feeding - The transportation of logs from log ponds or decks
to a mill for processing.
Mill Pond - See Log Storing.
Millwork - Any of a variety of interior woodwork items usually
decorative in nature.
Mineral Fiber - Fibers of inorganic nature used in the production
of insulation board.
Mixed Media Filtration - A combination of different materials
through which waste water or other liquid is passed for the
purpose of purification, treatment or conditioning.
Moisture Proofing - The application of moisture resistant
compounds to lumber to increase durability and resistance to
weathering.
Molded Products - Items produced by the molding of wood particles
with resins.
Multiple Saw Headrig - A headrig which has several saws for
varied cuts, eliminating multiple passes by the headsaw, thus
increasing efficiency.
Narrow-Kerf Saw - A saw with a thinner blade than normally used.
Oligosaccharide - A sugar which contains units of from two up to
eight simple sugars.
Overrun - In a saw mill, the difference between the measured
volume of a log and the actual volume of the lumber produced.
Particleboard - A sheet material manufactured from
lignocellulosic pieces or particles, as distinguished from
fibers, combined with a synthetic resin or other suitable binder
and bonded together under heat and pressure in a hot-press, or
extruded, by a process in which the entire inter-particle bond is
created by the added binder.
Patching Material - A high viscosity, putty-like substance
commonly used to fill knot holes and other large surface defects
in the face veneers of plywood panels as one of the initial steps
in the manufacture of prefinished panels.
-------
Pentachlorophenol - A crystalline compound, C£C15OH, used as a
wood preservative, fungicide and disinfectant.
pjj - A measure of acidity or alkalinity of a water sample. It is
equal to the negative log of the hydrogen ion concentration.
Phenols - A class of aromatic organic compounds in which one or
more hydroxy groups are attached directly to the benzene ring.
Phenol-formaldehyde Resin - A synthetic, oil soluble resin
produced as a condensation product of phenol and formaldehyde,
Phenolic Resins - Synthetic, thermosetting resins, usually made
by the reaction of phenol with an aldehyde.
Picker Roll - Device used to ensure uniform mat thickness in
dry felting operation.
the
Pigment - The fine, solid particles used for color or other
properties in the manufacture of paints and coatings.
Pitch - An organic deposit composed of condensed hydrocarbons
removed from the wood and which may deposit on the surface of saw
blades.
Planer Shavings - See Fractionated Wood.
Planing Mill - Consists of planers which produce smooth surfaces
on lumber.
Platens - The flat plates in the hot-press which compress the
mats into particleboards.
Polyester Resin - A synthetic, thermosetting resin formed by a
chain of molecules, composed alternately of molecules of acid and
alcohol. The chain formation linking the molecules together is
polymerization.
Polymerization - A chemical reaction involving a successive
linkage of molecules.
Polyvinyl Acetate Resins - Synthetic, thermoplastic resins,
commonly used in the manufacture of emulsion coatings.
Polyvinyl Chloride Film - A special plastic film produced by
calendering techniques and used in overlaying various wood-based
substrates to produce textured and printed decorative products.
Prefinished Panels - Any type of wood-based panel which is
factory finished and requires no further finishing by the user.
Pregluing - Operations concerned with drying, preservative
dipping or spraying, planing, grading, end or edge jointing and
cutting to length. These are necessary steps to prepare lumber
for gluing.
-------
Prepress - A press which prepares particle mats for the hot press
by partial consolidation of fibers.
Preservative Dipping - The chemical treatment of green lumber
prior to stacking. Lumber is dipped in a bath solution usually
containing pentachlorophenol.
Pressed Bark - Bark transformed into logs or briquettes under
pressure and heat.
Press Pit - A sump under the press.
Press Platen - See Platen.
Primary Clarifier - The first settling tank through which waste
water is passed in a treatment system.
Prime Coating or Primer — A special coating designed to provide
adequate adhesion of a coating system to an uncoated wood surface
and thus to allow for the exceptional absorption of the medium.
Product Mix - The fractional breakdown of the sum total of
different types of products produced in a plant.
Protein Resin - A protein based resin; usually soya based.
Pulping System - A fiber preparation system.
Quad Band Headrig - Two pairs of band saws used to accomplish
initial log breakdown.
Radio Freguencv Curing - A method of curing synthetic resin glues
by radio frequency heat generated by the application of an
alternating electric current, oscillating in the radio frequency
range, to a dielectric material.
Refiners - Particle forming machines. Refiners are of two types:
1) Mechanical Refiner - a particle forming machine
consisting of either two rotating disks or a
rotating disk and a stationary plate. The
particles produced in passing through the rotating
apparatus are fine in nature and thus are used for
face stock.
2) Thermo-mechanical Refiner - A disk type particle
forming machine which employs the aid of heat and
pressure to soften the feed wood, producing fibers
that are longer and stronger than those of a
standard mechanical refiner.
Rehumidification - The addition of moisture to a finished board
to prevent warping.
-------
Resin - A semi-solid or solid mixture of organic or carbon-based
compounds which may be drawn from animal, vegetable or synthetic
sources and may be thermosetting or thermoplastic.
Resin-Impregnated Paper - A type of paper, most commonly either
heavy kraft paper or refined alpha paper impregnated to varying
degrees of saturation with various types of resins for the
purpose of overlaying plywood and other types of wood-based
panels. The most common types of resins used are: melamine and
phenolic formaldehyde, polyester resins and acrylic types.
Resonance Frequency Device - A heating device using high
frequency radio waves to internally cure resins in particleboard.
Resorcinol - A crystalline phenol with the formula C<>Hi*(OH)2
obtained from various resins or artifically and used in making
resins.
Reverse Roll Coating - A method used in applying liquid finishing
materials to flat substrate surfaces. The equipment consists
basically of two parts; first, a direct roll coater which
deposits a heavy coat of liquid material onto the substrate
surface; second, a highly polished, chrome plated roll, rotating
in the opposite direction of the applicator roll. The reverse
acting roll wipes and polishes the substrate surface, filling the
low spots and pores and removing the excess liquid material.
Ring Debarker - See Barker.
River Impoundment - A natural or man-made area of a river which
is suited for the grouping and storage of logs.
Rotary Jet Drum Dryer - A particle dryer which uses a high-
velocity air jet to produce a spiral flow of particles in a
horizontal drum.
Roundwood - Wood that is still in the form of a log.
Rubber-Base Contact Cement - Typically a dispersion of neoprene
elastomer in organic solvents. Used quite extensively in the
bonding of decorative plastic laminates to plywood or
particleboard normally applied to both surfaces and allowed to
dry to a tack-free state before assembly.
Sawdust - See Fractionated Wood.
Saw Mill - A plant which consists of varied operations necessary
to reduce the raw material, i.e., log or cant to a useable wood
product.
Scrag Mill - Generally used for small diameter logs, consisting
of one or more pairs of circular saws with each pair in tandem.
Sealer - A liquid finishing material which is applied with the
primary purpose of stopping the absorption of succeeding coats.
-------
Seal Water - Water used as a seal in vacuum pumps.
Sedimentation - The gravity separation of suspended solids.
Septic Tank - A single-story settling tank in which the settled
sludge is in immediate contact with the waste water flowing
through the tank, while the organic solids are decomposed by
anaerobic bacterial action.
Settling Ponds - An impoundment for the settling out of
settleable solids.
Settling Tank - A tank or basin, in which water, domestic sewage,
or other liquid containing, settleable solids, is retained for a
sufficient time, and in which the velocity of flow is
sufficiently low to remove by gravity a part of the suspended
matter.
Setworks - The devices used to secure and position the logs on a
carriage for cutting.
Shake - A shingle split from a piece of log, usually three or
four ft long.
Sheathing - Asphalt impregnated insulation board.
Shotgun - A piston-cylinder arrangement, steam, air, or hydraulic
driven, which powers the log carriage.
Size - An additive which increases water resistance.
Slash - To cut logs to size.
Softwood - Wood from evergreen or needle bearing trees.
Solvent Base Coatings - All non-water base or non-water soluble
coating materials.
Solvents - Products which dissolve or disperse the film forming
constituents of surface coating materials which usually
volatilize during drying and therefore do not become a part of
the film itself. Solvents are required to control the
consistency of the liquid finishing material to obtain suitable
applicating properties.
Sound Deadening Board - A type of insulation board that has to
meet only minimal industrial standards.
Special Plastic Films - A wide variety of thermoplastic films
widely used for overlaying various types of wood-based
substances.
-------
Specialty Mill - A saw mill which produces a particular specialty
item rather than a general range of products.
Spray Booth - An enclosure, used in conjunction with spray
coating equipment, designed to provide fire and air pollution
protection by removal of both the solvent fumes and the spray
mist associated with spray coating operations. Spray booths are
of two types: 1) a water-wash type which uses water as the
filtering media and 2) a dry-type which uses dry filter elements.
Spray Coating - A method used in applying liquid finishing
materials to almost all types of wood-based substrates,
accomplished by various types of spray equipment including fixed
gun, reciprocating arm and rotary arm spray equipment,
Spray Evaporation - A method of waste water disposal in which the
water in a holding lagoon equipped with spray nozzles is sprayed
into the air to expedite evaporation.
Spray Irrigation - A method of disposing of some organic waste
waters by spraying them on land, usually from pipes equipped with
spray nozzles.
Stabilizers - Materials such as compounds of lead, tin and
cadmium-barium commonly added to resin compounds to minimize
chemical degradation when the material is exposed to elevated
temperatures or ultraviolet rays of the sun.
Stain - A transparent or semi-transparent liquid material made
from dyes, finely divided pigments or chemicals which when
applied to wood surfaces changes the color without disturbing the
texture or markings.
Staining - A spraying process which gives lumber a more pleasing
color.
Steaming - Treating wood material with steam to soften it.
Substrate - A material such as a wood-based panel coating or
adhesive containing substance is applied for the purpose of
finishing or bonding of an overlay.
Surge Area or Bin - An area in the forming machine which consists
of a bin that is kept at a constant level so that continuity of
particle flow is maintained.
Synthetic Resins - Complex, organic semisolid or solid materials
built up by chemical reaction of comparatively simple compounds.
Synthetic resins often approximate the natural resins in various
physical properties; namely, luster, fracture, comparative
brittleness, insolubility in water, fusibility, or plasticity
when exposed to heat and pressure and, at a certain more or less
narrow temperature range before fusion, a degree of rubber like
-------
extensibility. They commonly deviate widely from natural resins
in chemical constitution and behavior with reagents.
Tack - The ability of a resin to adhere.
Thermomechanical Pulping - Fiber preparation by disk refining and
pretreatment of the wood by pressurized steam.
Thermomechanical
- See Refining.
Thermoplastic Resins - Resins which soften and may
under heat and pressure.
be reformed
Thermosetting Resins - Resins which undergo permanent physical
and chemical change through the application of heat and pressure.
Ties - Conventional rail and track ties.
TLM 96 - The concentration of a toxic substance that causes
of a group of test organisms to die by the end of 96 hours.
half
TOP Coat - A liquid finishing material, usually applied as the
final finish coating for any prefinished wood product.
Total Tree Harvesting - The in situ chipping and subsequent
utilization of a whole tree.
T-PO4-P - Total phosphate as phosphorus.
Trimming - The final sawing of boards, prior to drying, to square
ends of lumber and remove defects.
TSS (Total Suspended Solids) - Total material retained by a
filler of a specified porosity, expressed in mg/1.
Tunnel Dryer - An enclosure through which wet mats are passed and
dried by means of forced hot air.
Turbidity - 1) A condition in water or waste water caused by the
presence of suspended matter, resulting in the scattering and
absorption of light rays. 2) A measure of the fine suspended
matter in liquids. 3) An analytical quantity usually reported in
arbitrary turbidity units determined by measurements of light
detraction.
Urea-formaldehyde Resin - A synthetic
condensing urea with formaldehyde.
resin produced by
Urea-Resin Glue - A synthetic-resin adhesive system based on the
thermosetting, urea-formaldehyde resin, used in overlaying
veneers and hardboard onto particleboard substrates as well as in
other wood gluing operations.
Y or U-Grooves - Machine cut grooves, cut into wood-based panel
substrates in the production of prefinished wall paneling.
it i* 3
-------
Grooves are usually either V or U-shaped and are regularly or
random-spaced throughout the length of the panel,
Varnish - A homogeneous transparent or translucent liquid
material which, when applied as a thin film, hardens upon
exposure to air or heat, by evaporation, oxidation,
polymerization or a combination of these to form a continuous
film that imparts protective or decorative properties to wood
finishes.
Veneer Cutting - There are four basic methods:
the
1) Rotary lathing - cutting continuous strips by
use of a stationary knife and a lathe.
2) Slicing - consists of a stationary knife and an
upward and downward moving log bed. On each down
stroke a slice of veneer is cut.
3) Stay log - A flitch is attached to a "stay log," or
a long flanged, steel casting mounted in eccentric
chucks on a conventional lathe.
4) Sawn veneer - veneer cut by a circular type saw
called a segment saw. This method produces only a
very small quantity of veneer. (see also Segment
Saw)
Veneer Drying - Freshly cut veneers are ordinarily unsuited for
gluing because of their wetness and are also susceptible to
molds, fungi, and blue stain. Veneer is usually dried as soon as
possible, to a moisture content of about 10 percent.
Vinyl Acetate - A colorless liquid with the formula CH2CHCO2CH3
used in the manufacture of synthetic vinyl resins.
Vinyl Resins - Synthetic, thermoplastic resins formed by the
polymerization of a vinyl compound, with or without some other
substance.
Water Base or Water Reducible Coatings - Emulsions (of high
molecular weight), dispersions (of fine particle size) and other
water soluble coating systems which, at application of solids,
comprise a minimum of 80 per cent of their volatile as water,
with the balance as exempt solvent.
Water Soluble Adhesive - An adhesive requiring water for
preparation; used in product fabrication and finishing
operations.
Wax Emulsion - A sizing compound.
Wet Decking - See Log Storing.
Wet Scrubber - An air pollution control device which involves the
wetting of particles in an air stream and the impingement of wet
or dry particles on collecting surfaces followed by flushing.
-------
Wood Chips - See Fractionated wood.
Wood Flour - Produced from the attrition of wood materials into
very small particles.
-------
TABLE 104
CONVERSION TABLE
cr>
MULTIPLY
acre
acre - feet
board foot
British Thermal
Unit
British Thermal
Unit/pound
cubic feet/minute
cubic feet/second
cubic feet
cubic feet
cubic inches
degree Fahrenheit
feet
gallon
gallon/Canute
horsepower
inches
inches of mercury
pounds
pounds/cubic ft
million gallons/day
mile
pound/square inch
(guage)
square feet
square inches
1000 board ft
tons (short)
yard
ABBREVIATION
ac
ac ft
bd ft
BTU
BTU/lb
by
CONVERSION
0.405
1233.5
12.0
0.252
0.555
TO OBTAIN
ABBREVIATION
ha
cu m
cu ft
kg cal
kg cal/kg
cfm
cfs
cu ft
cu ft
cu in
oF
ft
gal
gpm
hp
in
in Hg
Ib
Ib/cu ft
mgd
mi
psig
sq ft
sq in
1000 bd ft
ton
0.028
1.7
0.028
28.32
16.39
0.555 (°F-32)*
0.3048
3.785
0.0631
0.7457
2.54
0.03342
0.454
16.05
3,785
1.609
(0.06805 psig +1)*
0.0929
6.452
2.36
0.907
cu nyftun
cu m/min
cu m
1
cu cm
°C
m
1
I/sec
kw
cm
atm
kg
kg/cu m
cu m/day
km
atm
sq m
sq cm
cu m
kkg
yd
0.9144
m
hectares
cubic meters
cubic feet
kilogram-calories
kilogram calories/
kilogram
cubic meters/minute
cubic meters/minute
cubic meters
liters
cubic centimeters
degree Centigrade
meters
liters
liters/second
kilowatts
centimeters
atmospheres
kilograms
kilograms/cubic meters
cubic meters/day
kilometer
atmospheres
(absolute)
square centimeters
square centimeters
cubic meters
metric tons
(1000 kilograms)
meters
*Actual conversion, not a multiplier
-------
-------
------- |