EFFLUENT LIMITATIONS
GUIDELINES AND STANDARDS
OF PERFORMANCE FOR THE
INSULATION FIBERGLASS
INDUSTRY
4
U.S. ENVIRONMENTAL PROTECTION AGENCY
E« $
'II
DO NOT QUOTE OR CITE
-------
DEVELOPMENT DOCUMENT
for
EFFLUENT LIMITATIONS GUIDELINES
and
NEW SOURCE PERFORMANCE STANDARDS
INSULATION FIBERGLASS MANUFACTURING INDUSTRY
William D. Ruckelshaus
Administrator
Robert L. Sansom
Assistant Administrator for Air & Water Programs
Allen Cywin
Director, Effluent Guidelines Division
Michael W. Kosakowski
Project Officer
May 1, 1973
Effluent Guidelines Division
Office of Air and Water Programs
U.S. Environmental Protection Agency
Washington, D. C. 20460
-------
REVIEW NOTICE
This document presents conclusions of a study conducted by the Effluent
Guidelines Division, U. S. Environmental Protection Agency in support
of proposed requlations providing effluent limitations guidelines and
standards of performance for new sources in the insulation fiberglass
industry.
The conclusions and recommendations contained in this doucment may be
subject to subsequent revisions during the document review process, and
as a result the proposed effluent limitations guidelines, standards of
performance and pretreatment standards contained within this document
may be superceded by revisions prior to publication in the Federal
Register on or before October 18, 1973, as required by the Federal Water
Pollution Control Act, as amended (33 U.S.C. 1251, 1314 and 1316, 86
Stat. 816 et seg.) (the "Act").
n
-------
ABSTRACT
This document presents the findings of an extensive study of the
Insulation fiberglass industry by the Environmental Protection Agency
for the purpose of developing effluent limitations guidelines, Federal
standards of performance, and pretreatment standards for the industry,
to implement Sections 304, 306 and 307 of the "Act".
Effluent limitations guidelines contained herein set forth the
degree of effluent reduction attainable through the application of the
best practicable control technology currently available and the degree
of effluent reduction attainable through the application of the best
available technology economically achievable which must be achieved by
existing point sources by July 1, 1977 and July 1, 1983 respectively.
The standards of performance for nev/ sources contained herein set forth
the degree of effluent reduction which is achievable through the appli-
cation of the best available demonstrated control technology, processes,
operating methods, or other alternatives. The proposed regulations for
all three levels of technology set forth above establish the requirement
of no discharge of process waste waters to navigable waters.
Pretreatment Standards for "new sources" discharging to municipal
sewerage systems are set forth in "Pretreatment of Discharges to Publicly
Owned Treatment Works," C.F.R. .
Supportive data and rationale for development of the proposed
effluent limitations guidelines and standards of performance are con-
tained in this reoort.
«» BJFPfi?MD Ate'
as;;w nv a^.
111
-------
CONTENTS
Section Page
I Conclusions 1
II Recommendations 2
III Introduction 3
IV Industry Categorization 24
V Waste Characterization 29
VI Selection of Pollutant Parameters 35
VII Control and Treatment Technology 39
VIII Cost, Energy and Nonwater Quality Aspect g-j
IX Effluent Reduction Attainable Through the 73
Application of the Best Practicable Control
Technology Currently Available— Effluent
Limitations Guidelines
X Effluent Reduction Attainable Through the 77
Application of the Best Available Technology
Economically Achievable — Effluent Limitations
Guidelines
XI New Source Performance Standards and 78
Pretreatment Standards
XII Monitoring 79
XIII Acknowledgments 82
XIV Bibliography 83
XV Glossary 85
-------
FIGURES
I Flame Attenuation Process g
II Rotary Spinning Process g
III How Fiberglass Is Made g
IV Wire Mesh Chain Cleaning 17
V Size Distribution of Glass Wool Plants 23
VI General Water Flow Diagram for an Insulation 30
Fiberglass Plant
VII Biological Treatment at Plant A 40
VIII Water Flow Diagram of Plant A 45
IX Schematic Diagram of Plant B 48
X Water Flow Diagram of Plant B 49
XI Water Flow Diagram of Plant E 51
XII Chain Cleaning at Plant E 52
XIII Water Flow Diagram of Plant F 54
XIV Flow Chart for Plant G 56
XV Water Flow Diagram of Plant D 58
XVI Effect of Plant on Cost of Water Recycling in 69
Wool Plants
XVII Investment Cost Versus Plant Size 70
XVIII Annual Operating Costs Versus Plant Size 71
-------
TABLES
Page
I Properties Related to Applications of Glass Fibers 10
II Chemical Compositions of Glasses Used to Form 11
Commerical Fibrous Glass
III Primary Fibrous Wool Products 14
IV Fibrous Glass Mate-Basis Forms 15
V Fibrous Glass Packs-Basis Forms 16
VI U.S. Shipments and Value of Wool Glass Fiber 20
1964-1971
VII Insulation Fiberglass Plants 22
VIII Chain Wash Water Usage 31
IX Raw Waste Loads for Insulation Fiberglass Plants 32
X Sieve Analysis on Waste Gullet Water 33
XI Biological Treatment System at Plant A 41
XII Water Pollution Abatement Status of Existing Primary 43
Insulation Fiberglass Plants
XIII A Comparison between the Alternate Treatment and Control 62
Technologies
XIV Water Pollution Abatement Costs for Total Recycle 63
XV Estimated Cost of Waste Water Treatment for Insulation 65
Fiberglass Manufacture
XVI Summary of Capital and Operating Cost Effects: 66
Wool Glass Fiber
XVII Effects on Returns on Investment: Wool Glass Fiber 67
XVIII Conversion Table 91
-------
SECTION I
CONCLUSIONS
Notice
This document is a preliminary draft. It has
not been formally released by EPA and should
not, at this stage, be construed to represent
Agency policy. It is being circulated for
comment on its technical accuracy and policy
implications.
For the purpose of establishing effluent limitations guidelines and
standards of performance, the insulation fiberglass industry as a
whole serves as a single logical category. Factors such as age, size
of plant, process employed, geographic location, and waste control
technologies do not justify the segmentation of the industry into any
subcategories. Similarities in waste loads and available treatment
and control technologies further substantiate this.
Presently, 6 of the 19 operating plants are achieving no discharge of
waste wasters to surface waters. It is further concluded that the
remainder of the industry can achieve the requirement as set forth
herein by July 1, 1977. It is estimated that the costs of achieving
such limitations and standards by all plants within the industry is
less than $10 million. These costs would increase the capital invest-
ment in the industry 1.6 to 3.8 percent. As a result, the increased
costs of insulation fiberglass to compensate for pollution control
requirements would range from 0.6 to 3.8 percent under present conditions
JOTICE: TKESE *3E l-!'TJrr.- - • V'v: ;K r;j P,T>DIIT *ND ARE
SOSJtC! TO CiMKDES E/.SI2 .:•„; ' . : .,.? ,1 RUHEfl BY EPA.
-------
SECTION II
RECOMMENDATIONS
No discharge of process waste waters to navigable waters is
recommended as the effluent limitations guidelines and standard of
performance for the insulation fiberglass industry. This represents
the degree of effluent reduction obtainable by existing point sources
through the application of the best practicable control technology
currently available, and the best available technology economically
achievable. This also represents, for new sources, a standard of
performance providing for the control of the discharge of pollutants
which reflects the greatest degree of effluent reduction achievable
through application of the best available demonstrated control tech-
nology, processes, operating methods or other alternatives.
The technologies on which such limitations and standards are based
utilize reuse of the waste waters within the process.
-------
SECTION III
INTRODUCTION
Purpose and Authori ty
Section 301(b) of the Act requires the achievement by 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 by 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 toward the national goal of
eliminating the discharge of all pollutants, as determined in accor-
dance with regulations issued by the Administrator pursuant to Section
304(b) to the Act. Section 306 of the Act requires the achievement by
new sources of a Federal standard of performance providing for the
control of the discharge of pollutants which reflects the greatest
degree of effluent reduction which the Administrator determines to be
achievable through the application of the best available demonstrated
control technology, 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
within one year of enactment of the Act, regulations providing guide-
lines 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 reduc-
tion attainable through the application of the best control measures and
practices achievable Including treatment techniques, process and procedure
innovations, operation methods and other alternatives. The regulations
proposed herein set forth effluent limitations guidelines pursuant to
Section 304(b) of the Act for the insulation fiberglass subcategory of
the glass manufacturing source category.
Section 306 of the Act requires the Administrator, within one year
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
within the insulation fiberglass manufacturing subcategory of the glass
manufacturing source category, which was included within the list published
January 16, 1973.
Summary of Methods Used for Development of the Effluent Limitations
Guidelines and Standards of Performance
The effluent limitations guidelines and standards of performance
proposed herein were developed in the following manner. The point source
category was first categorized for the purpose of determining whether
separate limitations and standards are appropriate for different segments
within a point source category. Such subcategorization was based upon
raw material used, product produced, manufacturing process employed, and
other factors. The raw waste characteristics for each subcategory were
then identified. This included an analyses of (1) the source and volume
of water used in the process employed and tine sources of waste and waste
waters in the plant; and (2) the constituents (including thermal) of all
waste waters including toxic constituents and other constituents which
result in taste, odor, and color in water or aquatic organisms. The
constitutents of waste waters which should be subject to effluent limita-
tions guidelines and standards of performance were identified.
The full range of control and treatment technologies existing within
each subcategory was identified. This Included an identification of each
distinct control and treatment technology, including both inplant and end-
of-process technologies, which are existent or capable of being designed
for each subcategory. It also included an identification in terms of the
amount of constituents (including thermal) and the chemical, physical,
and biological characteristics of pollutants, of the effluent level result-
ing from the application of each of the treatment and control technologies.
The problems, limitations and reliability of each treatment and control
technology and the required implementation time was also identified. In
addition, the non-water quality environmental impact, such as the effects
of the application of such technologies upon other pollution problems,
including air, solid waste, noise and radiation were also identified. The
energy requirements of each of the control and treatment technologies was
identified as well as the cost of the application of such technologies.
-------
The information, as outlined above, was then evaluated in order to
determine what levels of technology constituted the "best practicable
control technology currently available," "best available technology
economically achievable" and the "best available demonstrated control
technology, processes, operating methods, or other alternatives." In
identifying such technologies, various factors were considered. These
included the total cost of application of technology in relation to the
effluent reduction benefits to be achieved from such application, the
age of equipment and facilities involved, the process employed, the
engineering aspects of the application of various types of control tech-
niques process changes, non-water quality environmental impact (including
energy requirements) and other factors.
The data for identification and analyses were derived from a number
of sources. These sources included EPA research information, published
literature, previous EPA technical guidance for insulation fiberglass
manufacturing, qualified technical consultation, and on-site visits and
interviews at exemplary insulation fiberglass manufacturing plants through-
out the United States. All references used in developing the guidelines
for effluent limitations and standards of performance for new sources
reported herein are included in Section XIV of this document.
General Description of the Industry
The category covered by this document is the insulation fiberglass
industry, a subpart of the Standard Industrial Classification 3296 in
which molten glass is either directly or indirectly made, continuously
fiberized and chemically bonded with phenolic resins into a wool-like
insulating material. This will be referred to as a primary process in
contrast to a secondary operation in which waste textile or wool fiber-
glass is processed into an insulation product. Insulation fiberglass
research and development laboratories are also excluded in this report.
The term insulation fiberglass is synonymous to the terms glass wool and
construction fiberglass.
The modern fiberglass industry was born in the early 1930's when
the Owens Illinois Glass Company and the Corning Glass Works combined
their research organizations forming Owens-Corning Fiberglas. The
original method of producing glass fibers was to allow molten glass to
fall through platinum bushings, forming continuous thick threads of
soft glass. The glass streams are then attenuated (drawn) into thin
fibers by high velocity gas burners or steam. This process generally
referred to as flame attenuation is pictured in Figure I.
-------
FIGURE I
FLAME ATTENUATION PROCESS
Flame or Steam
Attenuation
Overspray
Binder Spray-
Furnace
Downward Draft
of Air
I [Molten Glass
j .Stream
I i Holes
Platinum Bushing
~
X. ''->Gl
ass Fibers
Mat
Wire Mesh Chain or Flight Conveyor
-------
In the 1950's, Owens-Corning Fiberglass and the Cie de St. Gobaln
perfected the centrifugal or rotary process. A single stream of molten
glass is fed into a rotating platinum distribution basket which dis-
tributes the glass on an outer rotating spinner. The spinner contains
a large number of small holes arranged in rows in the wall. The molten
glass is forced through the holes forming fibers which are then attenuated
90° from their forming direction by high velocity gas burners, air or
steam as depicted in Figure II. The output of a single spinner may be
0.23-0.45 metric tons per hour (500-1000 Ib/hr) and several spinners are
used to feed fiber to one line.
Figure III shows the basic insulation fiberglass processes. The
flame attenuation and rotary spinning processes have their own individual
merits. The flame attenuated product has greater longitudinal strength
because the fibers are attenuated in the same direction (away from the
gas or steam blower) and the lengths consequently align in one direction
to give added tensile strength. This property decreases damage to the
product upon installation. Rotary spun fibers, on the other hand, are
attenuated as they form on the circumference of a rotating disk. The
fiber lengths thus assume random directions as they fall. Flame attenuated
wools generally need less fiber (approximately 35% less) to achieve the
same thermal properties as rotary spun wools. Since the two products are
similarly priced, annual production ratings and plant capacities measured
in kilograms can be somewhat misrepresentative when comparing the economics
of the two processes. Rotary forming processes can produce more uniform
and finer fibers. They are also capable of producing huge tonnages of
wool, and for these reasons the rotary process now dominates the industry.
Borosilicate glasses and low alkali silicate glasses are generally
used in making glass fibers because of their.chemical durability. The
surface area to weight ratio of the glass fibers in wool products is so
great that even atmospheric moisture could seriously weather common
silicate glass fibers. Table I is a compilation of the uses for the
various types of glass and Table II lists their composition.
There are two methods of producing the molten glass that feeds the
fiberizing machine in the forming area. The older method Involves first
producing approximately one inch glass marbles and then feeding the
solidified marbles to a remelt furnace which in turn feeds the ffberizer
with molten glass. The marbles may either be produced at the plant site
or made at a centrally located plant and shipped to other plants. The
original purpose of this seemingly redundant procedure is to insure glass
uniformity before the fibers are made by visually inspecting the glass
-------
FIGURE II
ROTARY SPINNING PROCESS
Downward Draft
of air
I
Furnace
Attenuation A,Molten Glass
Air
tream
Assembly can swing
back and forth fpr Xjn £>
even distribution
of fibers |!
—Rotating Spinnfer
-Hole on Cylinflirical Wall
Hood Wall
: Spray Nozzle-
If
li
-a
V
Coated Fibers
fall to chain
;. Hood Wall
—Overspwry j ring
—Binder Sptay Ring
-------
FIGURE III
HOW FIBERGLASS IS MADE
PACK OR CURING OVEN
FABRICATE
.PACK CUBING OVEN
FABRICATE
-------
TABLE I
PROPERTIES RELATED TO APPLICATIONS
OF GLASS FIBERS
Glass Type
o
Fibrous-glass
Forms
Fiber Diameter
Range, nrn
1. Low-alkali lime- Textiles and
alumina borosilicatc mats
;?. Soda-lime borosilicate Mats
Textiles
7. Soda-lime borosilicate Wool (coarse)
1. Soda-11me
5. Lime-free soda
borosilicate
6. High-lead silicate
Packs (coarse
fibers)
Wool (fine)
(Ultrafine)
Textile
0.00585 - 0.00965
0.00760 - 0.0152
0.114 - 0.254
Fiber Diameter
Range, in.
Dominant
Characteristics
Principal Uses
0.0023 - 0.00038
Excellent dielectric
and weathering pro-
perties
0.0101 - 0.0152 0.00040 - 0.00060 Acid resistance
0.00585 - 0.00965 0.00023 - 0.00038
0.00030 - 0.00050 Good weathering
0.0045 - 0.010
Lew cost
0.00076 - 0.00508 0.00003 - 0.00020 Excellent weathering
0.0000(est)-0.00076 0.0000 - 0.00003
0.00584 - 0.00965 0.00023 - 0.00038 X-ray opacity
Electrical textiles. General
textiles. Reinforcement for
plastics, rubber, gyspum,
papers. General-purpose mats
Mats for storage - battery re-
tainers, for corrosion protec-
tion, water proofing, etc.
Chemical (acid) filter cloths,
anode bags
Thermal insulations.
products
Acoustical
Coarse fibers, only, for air and
liquid filters,'tower packing,
airwasher contact and elimi-
nator packs
Lightweight thermal insulations,
sound absorbers, and shock-
cushioning materials. All-glass
high-efficiency filter papers
and paper admixtures
Surgical pad strands, x-ray pro-
tection anrons. etc.
-------
TABLE II
CHEMICAL COMPOSITIONS OF GLASSES USED TO FORM
COMMERICAL FIBROUS GLASS (PERCENT) (4)
Type Si02 A1203 CaO MgO BJ) NaJ) K20 Zr02 T10 PbO Fe
1. Low-alkali, lime-
alumina borosilicate 54.5 14.5 22.0 8.5 0.5
2. Soda-lime boro-
silicate 65.0 4.0 14.0 3.0 5.5 8.5 0.5
3. Soda-lime boro-
silicate 59.0 4.5 16.0 5.5 3.5 11.0 0.5
4. Soda-lime 73.0 2.0 5.5 3.5 16.0
5. Lime-free soda
forosilicate 59.5 5.0 7.0 14.5 4.0 8.0 2.0
6. High-lead silicate 34.0 3.0 0.5 3.5 59.0
11
-------
marbles. The mechanical problems caused by seeds and bubbles are more
troublesome in fibers than massive glass because of the small glass
diameters involved. The assurance of better quality control in the
glass making stage, however, has contributed to the replacement of the
intermediate glass marble by direct feed furnaces. Currently only one
company operates marble-feed, flame attenuated processes.
Direct melt furnaces always feed rotary forming processes because
rotary spinners have high volume production capabilities which can only
be matched by direct melt furnaces. Furthermore the high cost of a glass
furnace usually necessitates that it be large, which in turn requires a
large plant capacity in order to be profitable. Both marble feed and
direct melt processes feed flame attenuation forming processes.
When production changes occur in a direct melt process the molten
glass flow is temporarily diverted from the fiberizers and quenched with
water. The glass immediately solidifies and fractures into fragments
resembling a mixture of sand and aggregate, which is termed cullet. A
major portion of the cullet is collected at the machine in hoppers for
reuse into the melting furnace. If the furnace is not bled by producing
cullet, the lighter components 1n the molten glass will volatilize and
the composition of the glass will be altered.
The quality of water needed for cullet cooling is not especially
critical and this water may be reused, with make up water added to com-
pensate for the water flashed off by contact with the hot glass. It is
not important that the water be cooled, but sufficient suspended solids
must be removed so as to prevent damage to the pumps. Colloidal silica
suspensions can be controlled by sufficient blowdown.
After the molten glass is divided into fibers and attenuated, the
fibers are sprayed in mid-air with a phenolic water-soluble binder and
forced by a downward air draft onto a conveyor chain which travels at
127 to 508 linear cm/sec (50-200 ft/sec). In many plants the newly formed
fibers are oversprayed with water at the same time that the binder is
applied. This overspray serves to cool the almost molten glass, minimiz-
ing volatilization and early polymerization of the binder.
The binder is a thermosetting resin composed of a dilute solution
of phenol-formaldehyde (resin) and other chemical agents such as ammonia
and surfacants. The latter two compounds serve as stablizers inhibiting
rapid polymerization of the resin. The resin itself is a complex mixture
of methy!olphenols in both the monomer and polymer states. A more detailed
12
-------
description of binders is given in reference 7. For some products
lubricants are applied to the new formed fibers singly or in addition
to the binder. The lubricant, usually a mineral oil, is used to
minimize skin irritation (fiber abrasion) of persons handling the in-
sulation. Tables III, IV, and V list the binders and lubricants used
for the various products. It should be noted that some mat and pack
products in these tables are textile products not covered by this
document. The properties and uses of each product are also listed.
The binder is diluted with water before it is applied to the product.
The quality of the diluted water is important 1n that it must not con-
tain solids of such size as to plug the spray nozzles and in that it
must not contain sufficient concentrations of chemicals that would
interfer with the curing properties of the binder.
As the fibers fall to the chain a thick mat is formed. This mat
then proceeds by conveyor through curing and cooling ovens, it 1s com-
pressed, and an appropriate backing (asbetos, paper, aluminium, etc.)
may be applied. The product is then sized and/or rolled and packaged.
There is currently a large demand for blow mold. This is made by
shredding standard insulation so that it may be poured into existing
walls. The thermal properties, however, are inferior to backed two inch
insulation.
The cured phenolic resin, imparts a yellow color to the glass wool
which may not be appealing to the customer. Consequently, various dyes
sometimes are applied to the fiberglass in the binder spray.
Two types of chains have been used in the forming area. Flexible
wire mesh conveyor belts were originally used, but many have since been
replaced by flight conveyors. These are hinged steel plates containing
numerous holes or slits. The air stream which transports the glass fibers
to the conveyor also contains droplets of resinous binder which have not
adhered to the glass fibers. Many of these droplets deposit resin on the
chain, and 1f not removed, the resin build-up will eventually restrict
passage of the air stream. When the deposit becomes sufficiently great,
blanket formation is no longer possible, necessitating replacement of
the conveyor.
A wire mesh chain has historically been cleaned while 1n service
to extend its useful operating period before becoming "blinded" with
resin deposits by routing the chain through a shallow pan containing
a hot caustic water solution (refer to Figure IV). Fresh caustic make-
up to the pans created caustic overflow containing phenolic resin and
glass fiber.
13
-------
TABLE III
PRIMARY FIBROUS-CLASS-UOOL PRODUCTS
Produce
Unbonded wool
("white")
Bonded wool
(molded)
Bonded wool
Bonded wool
Bonded wool
Bonded wool
(fine fiber)
Bonded wool
Sonded wool
(fine fiber)
Bonded wool
(fine fiber)
Basic fine
Fibers (bulk)
Nominal Fiber
Diameter, cm
0.013
0.0096
0.0086
0.013
0.016
0.016
0.0010
0.0020
0.0030
0.0030
0.0010
0.0043
0.00051
0.0030
0.0005-0.0030
Nominal Fiber
Diameter, In.
0,0005
0. 00038
0.00034
0.0005
0.0006
0. 0006
0.00004
0.00008
0.00012
0.00012
0.00012
0.00017
0.00002
0.00012
Density Range, .
K/Cu. Cm.
0.024 up
0.024-0.060
0.032-0.060
0.096
0.032-0.19
0.0096
0.0080
0.12-0.032
0.12-0.032
0.0048-0.0080
0.012-0.032
Density Range,
Ib/cu. ft.
1.5 up
3.0 std.
1.5-3.75
2.0-3.73
6.0
2.0-12.0
0.6
0.5
0.75-2.0
0.75-2.0
0.3-0.5
0.75-2.0
Maxioim Teagera-
Binder cure Limit, C
Oil only 538
Phenolic 204
resin
Phenolic 204
resin
Phenolic 204
resin
Phenolic plus 316
high-temp resin
Phenolic 204
resin
Phenolic resin 316
high-temp resin
Phenolic resin
SUicone otl
Phenolic plus 316
high-temp resin (600)
Phenolic 204
resin (400)
Phenol resin
SUicone oil
Phenol 204
resin (400)
Unbonded
Unlubricated
M.ilor Application
Hosted equipment 6 appliances
Pipe insulation-low temperature
ir.id low pressure heated pipe
/Opliance insulation
JOpliance insulation
lluct insulation-fire barrier
:.nsulatlon
Mineral purpose and fabricated
:!'>rms, rolls, bates, blocks,
hoards, (plain, faced, asphalt**
t.'-j), metal-mesh blankets; duct
:.i8ulation, pouring wool
ulrcraft Insulation
flotation application
Trapped on pipe insulation
:l}8ulation
General purpose insulation-eouod
i.'jncrol-shocit cushtng
Clothing interliner
:iiat cushioning
Rs.tlroad-car, truck-trailer,
and furnace Insulation
Fibers for paperaaklng
insulation. There 1- no low-terature
fs discereddoto -
thlCkn'" a°d
-------
TABLE IV
FIBROUS-GLASS MATS—BASIC FORMS
Product
Nominal Fiber
Diameter, mm
Primary Mat
Nominal Fiber
Diameter, in.
Products
Weight Range,
g/sq. cm.
Thickness1
Range, tm
Notes
Staple fiber mat 0.015 - 0.016
Reinforcing mat 0.058 - 0.096
Staple mat (ran-
dom-reinforced)
Base mat,
0.016
Staple mat (par- Base mat
allel-reinforced) 0.0.6
0.00060 - 0.00065
0.00023 - 0.00038 0.015 - 0.091
0.25 - 2.5
0.00065
0.00065
0.5
Resins, starch, gelatin
and sodium silicate
binder. ' Fibers in
random lay
Cut strands of continuous
filament bonded in jack-
straw (random) arrange-
ment. Resin-type binders
Base mat of staple fibers
intertwined with endless
continuous-filament
strand in a random ar-
rangement-.- Phenolic-bi nder
Base mat of staple fibers
interlaid with parallel
strands of continuous
filament for undirec-
tional strength. Phenolic
binder
Thickness measured at 2.75 psi. That is 11 Ib. load on 1/4-in. diameter platen.
-------
TABLE V
FIBROUS GLASS PACKS—BASIC FORMS
Product
Fiber Diameter
mm, Nominal
Fiber Diameter,
in., Nominal
Notes
Bonded packs
(coarse fibers)
0.11
0.15
0.20
2.5
0.0045
0.0060
0.0080
0.100
Packs 1/2 and 1 in. thick
water-soluble or insoluble
binders. Used in air
filters, air washers and
as distillation column
packing
Curly wool
0.029
0.00115
Bulk wool - usually lubri-
cated. Special uses in
process industries
16
-------
FIGURE IV - WIRE MESH CHAIN CLEANING (5)
Caustic Chain
Cleaning
Water Spray
Chain Cleaning
^4'^
1^
^ A
-\ v>w^-*%
"
-------
Another method of chain cleaning uses either fixed position pres-
surized water sprays or rotating water sprays. Unlike the caustic soda
bath processes, the waste waters from this method are amenable to treat-
ment and recirculation. Water spray chain cleaning has replaced caustic
chain cleaning at all but one plant which uses a combination of the two
methods. Although both methods have been used to clean wire mesh chains,
it is impratical to caustic clean flight conveyors. Unlike the flexible
wire mesh chains, the hinged plates of the flight conveyor cannot be so
easily routed through a pan. Furthermore a flight conveyor is more
expensive than a wire mesh chain, and corrosion caused by the caustic
is of greater concern. Spray cleaning has the added advantage of cooling
the forming chain, thereby decreasing both volitillzation and polymeriza-
tion of the phenolic resin and thereby lessening both air and water
treatment problems.
Pipe insulation is made in various ways. One principal method In-
volves wrapping uncured insulation about mandrels and curing the bundels
batchwise in ovens. The mandrel is a perforated pipe of the appropriate
dimensions. Caustic is still used by the Industry to batch clean mandrels,
However, the volumes involved are much less than those required for chain
washing and are consequently much less of a problem.
Another source of water pollution is hood wash water. The hood is
either a stationary or rotating wall used to maintain the air draft in
the forming area. It is necessary to wash the hood in order to keep any
wool that has agglomerated there from falling onto the chain and causing
nonuniformity of the product.
Air scrubbing water can be another major source of water pollution.
However, each plant has Its own method of air pollution abatement with
some even using completely dry processes.
Sales and Growth
The insulation fiberglass industry is a rapidly expanding industry
as illustrated by the fact that the industry is currently at 100 percent
production and several more plants and expansions are planned to be built.
Current annual production is estimated at 0.77 million metric tons (1700
million pounds) per year. Profits before tax on sales range from about
18
-------
9 percent to 20 percent with a median of 12 percent. Table VI summarizes
recent product and sales. Supply and demand projections estimate 8 percent
growth per year for the next five years. This picture may substantially
change 1n light of the fuel crisis, a situation which will create even
more demand for insulation materials.
The principal federal government Influence on demand is brought about
through changes or modifications in building code requirements. Such a
change took place recently when the Department of Housing and Urban Devel-
opment, Federal Housing Administration, revised the Minimum Property
Standards for multi-family and single-family housing in order to fulfill
the Department's commitments to the National Energy Conservation policy.
The revision, which took effect 1n July 1971 for single-family construc-
tion and in June 1972 for multi-family construction, went Into effect
immediately for all mortgage Insurance projects for which a letter of
feasilbility has not been issued and for low rent public housing projects
for which a program reservation has not been issued. This Implementation
will definitely provide more economical operating costs for the heating of
residential units and will also conserve the nation's energy resources.
The major uses for glass wool are wall insulation, roof decking,
acoustical tile, pipe insulation, ventilation d,ucts, and appliance and
equipment Insulation. In the areas of home Insulation and acoustical
tile, fiberglass has largely replaced its competition (e.g. mineral wool,
perlite, urethane, wool fiberboard, Tectum. lightweight concrete or
gypsum, foam glass, and ceramic insulation) because of the combined low
cost, light weight, excellent thermal properties, and fireprooflng
properties. The principal competion for non-residential uses are
urethane, styrene, and calcium silicate.
An estimated breakdown of products for the year 1971 1s given below.
As seen Batt insulation (standard two inch insulation) Is the principal
product.
ESTIMATE OF U.S. CONSUMPTION OF
WOOL GLASS FIBER, 1971
Batt Insulation 450 1000
Acoustic Tiles 41 90
Board Insulation 80 175
Pipe, Appliance and Equipment 75 165
Miscellaneous 25 60
TOTAL ~67I Thousand metric 1490 Million Ib
tons
19
-------
TABLE VI
U.S.SHIPMENTS AND VALUE OF WOOL GLASS FIBER 1964-1971
1964
1965
1966
1967
Insulation Use
Structural Building
Indus trial, Pipe &
Equipment
Total
MM Ib
368
570
938
$ MM
76.
151
227
C/lb
20.7
26.5
24.2
MM Ib
438
608
1046
$ MM
93
158
251
C/lb
21.1
26.0
24.0
MM Ib
484
608
1072
$ MM
105
173
278
C/lb
22.6
28.5
25.9
MM Ib
484
554
1038
$ MM
109
170
279
C/lb
22.5
30.7
26.9
3
"
PO
o
1968
Insulation Use
1969
1970
1971
MM Ib $ MM C/lb MM Ib $ MM c/lb MM Ib $ >JM C/lb MM Ib $ MM c/lb
25.2 644.8 165.6 25.7
158
Structural Building 557 133 23.9 627
Industrial,Pipe &
Equipment 567 179 31.6 675 198
Total 1124 312 27.8 1302 356
29.3 541.5 190.6 35.2
27.3 1186.3 355.8 30.0 1518.7 426.9 28.2
Note: Values are average manufacturers' net selling prices, f.o.b. plant, after discounts and allowances,
and excluding freight and.excise taxes.
Source: Department of Commerce "Current Industrial Reports"
-------
In summary, the insulation fiberglass industry Is a rapidly growing
one. At present only four companies produce fiberglass insulation. The
nineteen existing plants and the estimated production toy their parent
companies are listed in Table VII. Figure V is a production size
distribution graph of these plants. Because a high vrolume production
is necessary and the glass fiber operation is difficult to scale down,
there are no very small plants when compared to other Industries. The
smallest plant produces 2270 metric tons (5 million pounds) of specialty
products per year.
21
-------
TABLE VII
INSULATION FIBERGLASS PLANTS
Company
Owens-Corning
Fiberglas Inc.
Johns-Manville
Approximate Percent of
Industry Production
77
Pittsburgh Plate Glass
Industries
Certain-Teed
St. Gobain
10
3
10
Plant Locations
Barrington, N.J.
Fairburn, GA
Kansas City, KS
Newark, OH
Santa Clara, CA
Waxahachie, TX
Cleburne, TX
Corona, CA
Defiance, OH (3)
Parkersburg, HVA
Penbyrn, NJ
Richmond, IN
Winder, GA
Shelbyville, IN
Berlin, NJ
Kansas City, KS
Mountaintop, PA
22
-------
FIGURE V
SIZE DISTRIBUTION OF GLASS WOOL PLANTS
CO
10-
8'-
>L
ha
Pi
is*
^
"P^Tso
100
;SOOT 150
200
Annual Capacity
Thousands of metric tons per year
(Million Ib/yr)
-------
SECTION IV
INDUSTRY CATEGORIZATION
Introduction
In developing effluent limitations guidelines and standards of
performance for new sources for a given industry, a judgment must
be made by EPA as to whether effluent limitations!and standards are
appropriate for different segments (subcategories) within the industry.
The factors considered in determining whether such subcategories are
justified are:
1. Manufacturing Process
2. Chain Cleaning Process
3. Plant Size
4. Plant Age
5. Raw Materials
6. Product
7. Plant Location
8. Air Pollution Control Equipment
9. Wastes Generated
10. Treatability of Waste Waters
As the result of an intensive literature search, plant inspections,
and communications with the industry, it is the judgment of this Agency
that the primary insulation fiberglass industry can be considered as a
single category. Not included are secondary plants which process waste,
textile fiberglass and research and development facilities.
Factors Considered
1. Manufacturing Process
As described in Section III of this document, there are two types
of glass fiber forming processes: flame attenuation and rotary spinning.
Upon review of raw waste water loads and inspections of both types of
processes, it is concluded that tie manner of fiber forming has no direct
24
-------
effect on the quality of the waste waters, and hence subcategorization
on this point is not needed. The different manufacturing processes,
however, do have different air volume requirements which will affect wet
air pollution control. This point is later considered.
2. Chain Cleaning Process
As described in Section III, there are also two basic methods for
cleaning the forming chain of the glass fibers and phenolic resins.
One method consists of dragging the wire mesh chain, on its return path
to the forming area, through a hot caustic bath. The second method
consists of spraying the wire mesh chain or flight conveyor with high
velocity water.
The resultant wastes from caustic cleaning are extremely difficult
to treat and unless considerable dilution is provided, the wastes are
not suitable for recycling. The principle reason for this is that the
only practical sink for the waste waters in a completely closed system
is for overspray and binder dilution, and that unless diluted caustics
are incompatible with phenolic resins. The blowdown from spray washing
is amenable to treatment and recycle.
Two subcategories therefore would seem appropriate. However, at
the present time only one plant employs caustic chain wash. The remainder
of the industry has switched to spray washing and has future plans to
employ only spray washing equipment. The one existing plant that uses
caustic baths does so in conjunction with spray washing equipment and
it is not necessary in this case to blowdown from the caustic bath.
The carryover caustic on the chain is so diluted by the wash water
volumes that no problems are anticipated in the new recycle system.
For these reasons subcategorization according to chain cleaning
techniques is not necessary.
3. Plant Size
It has been determined from the data and from inspections that
for other than volumes of waters, plant size has no effect upon the
quality of waste waters and therefore it is not an adequate topic for
subcategorization. Plant size will only affect costs of treatment
systems when these costs are not directly related to plant capacity.
Smaller plants will bear a somewhat higher treatment systems cost than
larger plants.
25
-------
A. Plant A
Glass vool plasms span ss.age of fro?s5 2 years to more than 25
years sine® plant start up, $bout 30 .percent of the plants ars 10-15
years old while 25 percent aro less than 10 years old. All plant? that
ara at least. 2 ,?eara c^d have undergone considerable upgrading of the
efJGK processes «ad in eany cases facilities have bssn expanded
"test* P.aSlcn of state «?f the ar£ processes. The sajkr effects of
aqe wllv *^ of BWG SsgsvJfSs&Tjss In ths cost of Installing water
ling systems rather than differences en waste water characteristics.
H-snea, plant age 1s not an appropHate bssls fos* subcategorlzatlon.
5. Raw MatsHals
The raw materials rs^mlred for wool glass are much the sape as for
standard massive glass: 65 serceat, silica anct 35. percent fluxing oxides
(e.g. llrasstone and boratesV. l^e cosni?osit1or?s of typical glasses and
their uses have previously beep ^Ist^d Irs Tables 1 and II rsspsctlvely.
Ones the glass 1s ssade eithesr as fibsrs or collet, it 1s for all
practical purposes Inert, and thus will «ot chemically affect waste
water quality.
The typ« of r^sjn used, however, will sxert some Influence on
both air and water quality. The ipcSustry Is continually fomwlatlng
new binder mixtures in an effort to minimize air and water pollution
problems.
However, the industry should mt be subcategorlzed according to
typa of binder used for the following reasons. Different products can
require different binders and these can ba made at different times on
the sarae nj^cklna. Composition changes 1n the binder can occur at any
time, as the industry tries to improve the product and decrease raw
material costs. "Die Individual characteristics of each machine within
every plant determine hew quickly the waste resin will set up (i.e.,
polyraerise), and this is the principal factor affecting water quality.
No matter what rssin 1s used, the general waste characteristics are the
same and the treatment .system will "ret be affected as long as biological
treatment ^ not practiced„
6. Product
The type of product made will affect the chain wash water quality
in that different products may require different resins. However, for
the same reasons given above, the industry should not be subcategorlzed
on this topic.
26
-------
7. Plant Location
Geographical location will have an effect on waste water quality
only 1f water softening 1s required. From those plants inspected, 1t
was learned that the degrees of water treatment varies considerably
among the Industry. Waste water treatment practices on the softener
backwash also vary significantly, with some plants being able to incorpo-
rate these waste streams into the wash water system. Treatment of water
treatment system wastes are common to industry as a whole, and as such
does not merit subcategorization for each separate industry.
Geographic location may influence how a particular plant handles its
blowdown and waste streams. Three plants in rural areas with relatively
warm and dry climates are using evaporation ponds. Another plant has
sufficient land to use for spray irrigation. However, all plants have
the option of disposing of their blowdown in the overspray or binder
solution and subcategorization by geographic location is not necessary.
8. Air Pollution Control Equipment
The tyoe of system used to control air pollution will definitely
affect the water treatment scheme. In plants where dry air pollution
control equipment is adequate, high pressure, low volume chain sprays
are feasible, easing the water treatment problem.
However, each company has its option on how to handle its air
problems, and as such water quality should not be jeapordized when
alternate methods of air quality control are available. This item is
therefore not suitable for subcategorization.
9. Waste Generated
From evaluation of the available data it is concluded that the
types of wastes generated are common to all Insulation fiberglass plants.
The only exceptions are dyes and water treatment backwashes. The former
parameter presents no problem in so far as quality of recycled water.
The latter was previously covered under geographical location. Therefore'
the industry should not be subcategoHzed according to wastes generated.
10. Treatability of Waste Waters
From discussions with the Industry and from plant inspections it
was concluded that 1n a recycle system for a insulation fiberglass plant
only three basic parameters in the process water affect its treatabi1ity,
suspended solids, dissolved solids, and pH. The recycled waters can be
27
-------
adequately treated by course filtration, pH control (if necessary), fine
filtration or coagulation - settling, and sufficient blowdown as can
be handled. With proper design of the treatment system there should be
no forseeable reason other than plant expansion that these basic systems
need to altered in order to accommodate varying waste load characteristics.
Therefore treatability of waste water factors indicate that all insulation
fiberglass plants fit into a single category.
28
-------
SECTION V
HASTE CHARACTERIZATION
General
A general water flow diagram for an insulation fiberglass plant is
pictured in Figure VI. A complete analysis for each waste stream has
not been done by the industry since only the combined waste stream has
been of interest. As previously discussed, the principal process waste
streams within the process are the chain cleaning water and water sprays
used on the exiting forming air.
Flow Analysis
Table VIII lists chain wash water flows for plants of various sizes.
As seen there is no correlation between plant size and water usage for
chain washing. This is to be expected because each of the four insulation
fiberglass producers uses chain sprays of different pressures and therefore
different flow rates.
As previously mentioned, each company also employs different methods
of air pollution control. In those plants employing water sprays to clean
the forming air, this water flow may be the major process water flow.
Lastly, the different types of glass furnaces or melting pots have varying
cooling water requirements.
In summary, it is not possible to give a typical process water usage
for a given production or even to give a meaningful range of flows.
Raw Haste Loads
Table IX summarizes the raw waste loads for several plants. Although
the numbers are not completely comparable because of treatment differences
and different blowdown percentages, the table nevertheless shows a wide
variance in waste water composition. Other factors affecting the raw
waste load include binder composition, chain temperature, and other thermal
and time factors affecting the rate of resin polymerization.
One particular waste stream addressed by this report is cullet
cooling water. Suspended solids concentrations are extremely variable
and depend upon how many fiberizers are being by-passed. One company
estimated concentrations in the waste water to range from a few hundred
to tens of thousands mg/1 after simple settling. The same company did
a size distribution study of the suspended solids that appears as Table X.
29
-------
Rust and
Fungus Inhibitors
Looiing Water
FIGURE VI
GENERAL WATER FLOW DIAGRAM FOR AN INSULATION FIBERGLASS PLANT
Raw Materials
i Stack
Evaporation
Hood Spray— .
;tAcl
Melting
Furnace
I
Water.
Waste .
Water
\
Fiberizer
Gullet |x
Cooling
Water
Gullet
Waste V.'ater
Overspray
Resin, Chemicals ,
Dilution Water
Binder —
i
Stack
A
'Evaporatio
Q
IS
Hood
Water
Evaporation
\ir
Curing and Cooling j
Oven !
Chain Sp'ray
!CausFi>
Bath
_AZ._. Carryover
—Caustic
Makeup
Water
Water Snray.q
Waste Water
V
Waste
Water
Supply _\, Treatment
Air Pollution
Control Equipment
Air
Product
\
To Process
~l—
•L ; Forming
Drop
out
Boxes
Air
V
Backwash
and
Sludges
_ j_ Blowdown
"Boiler
-------
TABLE nil
CHAIN WASH WATER USAGE
Plant
A
B
C
0
£
F
G
Plant
Thousands of
Metric Tons
Per Year
120
34
34
27
16
16
14
Size1
Million pounds
per year
270
75
75
60
35
35
30
Water Usage
Chain Sprays
Uters/sec.
44
38
14
63
50
8
3
gpro
700
600
200
1000
800
120
48
All production figures are estimates.
31
-------
U)
TABLE IX
RAW WASTE LOADS
FOR INSULATION FIBERGLASS PLANTS
ant
H
F1
G
A
B1
D1
I
Phenol
mg/1
363
2564
4.11
212
240
11-98
BOD5
mg/1
156
7800
991
6200
900
COD
mg/1
2500-4000
43,603
6532
23,000
3,290
TSS
mg/i
116-561
360
76
769
200
690
TDS TURBIDITY
mg/1
3000-5000
822
10, 000-20 ,0002
16,000 200
40.0002
2,080
pH Percent
Slowdown3
8.3
7.7-8.9 13.0
1.5
8.0 1.0
2.3
6.1-12.2-
1 - Sample taken from water recirculation system
2 - Given by company with no backup data
3 - Defined as percent total process water used as overspray or binder dilution
-------
TABLE X
SIEVE ANALYSIS
ON
U.S. Sieve Number
Finer
50
100
140
200
325
400
Passed
WASTE CULLCT WATER
yUm Equivalent
297
149
105
74
44
37
% By Weight
Retained
98.30
1.20
0.30
0.05
0.01
0.05
0.09
100.
33
-------
As seen from, the table 99.50 percent of the cullet should be amenable
to primary settling. However, especially at high cullet producing
times, an appreciable amount of minus 100 mesh glass particles can
remain suspended in the waste water. Visual inspections at some plants
noted cullet scattered about the river banks below discharges of cullet
cooling water.
Summary
In summary, water usage and raw waste loads are not relatable in
a practical manner to production levels or techniques. Of the nineteen
existing plants, there may be as many different formulas for relating
these factors. There are significant differences between plants even
within the same company. A compensating factor, however, is the fact
that all such wastes are amenable to the same general type of chemical
and/or physical treatment.
34
-------
&v
SECTION VI
SELECTION OF POLLUTANT PARAMETERS
Selected Parameters
Upon review of the Corps of Engineers Permit Applications for
discharge of waste waters from insulation fiberglass plants, EPA
data, industry data, and observations madij during EPA plant inspections
the following chemical, physical, and biological constitutents con-
stitute pollutants as defined in the Act.
Phenols
BOD5
COD
Dissolved Solids
Total Suspended Solids
Oil and Grease
Ammonia
PH
Alkalinity
Color-
Turbidity
Temperature (Waste heat)
Specific Conductance
The rationale for the selection of the above parameters follow.
These parameters are present in the raw waste streams of all fiberglass
insulation plants. Pollutants in cooling systems (algae and corrosion
inhibitors) and 1n water treatment backwashes are covered by the Effluent
Limitation Guidelines Development Documents for Steam-Electric Power
Generation and Water Treatment.
Phenols
The basic constituents of the binder are phenol, formaldehyde,
urea, and ammonia which react to form various mono and poly methylol
phenols. Therefore, free phenols will always occur in any water that
has contact with uncured resin. Phenol concentrations range from 1 milli-
gram per liter (mg/1) in once through process waters to several hundred
mg/1 1n recycled waters. In the case of the higher concentrations, these
consist of colloidal suspensions of resins in a partially polymerized state.
However, as some companies have found, a significant portion of the total
phenols also occur in a free state.
35
-------
Biochemical Oxygen Demand (5 day)
Because of the nature of the organic compounds used 1n the binder,
a 8005 will exist. Values range from 40 mg/1 to 7,800 mg/1, with the
higher values again representing recycled waters. Data from one indus-
trial biological treatment plant show that this constituent is easily
treatable.
Chemical Oxygen Demand
For the same reasons as given above, a sizeable chemical oxygen
demand will exist in the raw waste stream. Values range from 150 mg/1
to 43,603 mg/1, the higher values occurring in recycled waters. A
94 percent reduction was accomplished by an activated sludge plant, but
the resultant levels in the effluent were still high (300 mg/1).
Dissolved Solids
Dissolved (filtrable) organics and super-fine colloidal organics,
that are classified as being filtrable according to Standard Methods (12),
will increase the background dissolved solids concentrations significantly
as a result of chain washing and wet air pollution control. Values range
from net increases of 200 mg/1 to gross concentrations of 40,000 mg/1. A
closed water cycle will significantly raise the level of this parameter.
Total Suspended Solids
Conglomerated glass fibers and partially polymerized resins will
appear as suspended solids in the chain wash water. Values have been
reported to be as high as 770 mg/1 in untreated waste waters.
Oil and Grease
Mineral oils are frequently added to the binder to alleviate abrasion
problems. The amounts of lubricant used are proprietary information but
relatively small. Slight oil sheens have been noted in the waste streams
of some plants during inspections. Values for final effluents range from
7.5 mg/1 to 140 mg/1.
Ammonia
Ammonia is typically added to the binder for stabilization purposes.
The rate of binder polymerization is decreased by an increasing pH.
Ammonia is also added to the chain wash water to inhibit polymerization
in order to minimize screen and filter plugging. Aimonia concentrations
in effluents range from 0.6 mg/1 to 4.83 mg/1.
36
-------
As previously mentioned the binder polymerization reaction Is
pH dependent. Unless neutralization Is practiced, waste water from
a fiberglass Insulation plant will be alkaline with a pH greater
than 9.0.
Alkalinity
The presence of alkalinity has already been established in the
pH discussion. Alkalinity determined as equivalent mg/1 of calcium
carbonate ranges from 285 mg/1 to 5,000 mg/1.
Color
Color will result from both the polymerized resin (yellow to brown)
and any dye that is added to the product in the binder spray. Colored
waste streams have been seen at nearly all the plants inspected. It is
especially notable at plants with process water recirculation systems.
Turbidity
Turbidity is a measure of the light absorbing properties of the
constitutents in water. For a fiberglass insulation plant these result
from colloidal suspensions and from dyes. Values range from 55 to 133
Jackson Turbidity Units for once through waters.
Temperature
Since high temperatures are required to make molten glass (2700°F.),
thermal increases in contact and non-contact waters will be noted.
Specific Conductance
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 the water and the water tem-
perature. Thus in the absence of a large amount of colloidal solids
that are analytically classified as dissolved (filtrate), specific con-
ductance will be proportional to the total dissolved solids concentration.
For qualitative measurements this is a quicker and more practical method
of monitoring dissolved solids.
37
-------
Condensed Parameter List
Although all of the above parameters will result from the insulation
fiberglass process, only a few need be monitored to Insure that pollutants
are not discharged:
Phenols
COD
Total Dissolved SolIds
Total Suspended Solids
pH
Color
Temperature
Specific Conductance
The remaining five parameters will always appear 1n combination with
one or more of the above parameters. To further pursue this point an
absolute minimum of only three parameters, specific conductance, tempera-
ture, and total suspended solids need be monitored to Insure that the
recycle systems are operating. A deviance 1n any one of these parameters
will signal that something is amiss and that analysis of the remaining
parameters is necessary. These particular parameters need only be con-
sidered because any waste stream in an insulation fiberglass plant will
significantly contain one to all three of these parameters.
38
-------
SECTION VII
CONTROL AND TREATMENT TECHNOLOGY
Historical Treatment
In only one Insulation fiberglass plant has other than primary treat-
ment to an effluent been applied. Plants have historically discharged
their waste streams to municipal sewage treatments rather than install
secondary or more advanced treatment systems. Use of biological treatment
as an end-of-pipe treatment for phenolic waste waters was attempted at one
Insulation fiberglass plant (Plant A). The treatment scheme (Figure VII)
consisted of equalization, alum coagulation, nutrient addition, temperature
control, extended aeration, post chlorination, aerobic sludge digestion,
and vacuum filtration. It is noteworthy that the recirculation system was
installed some thirteen years ago and that only the blowdown received bio-
logical treatment. Table XI summarizes the performance of the system.
However, despite the percent removal efficiencies of the treatment system,
objectionable concentrations of phenol and COD were still being discharged.
One parameter that received no treatment other than dilution was
color. A bright pink dye is applied to many of the products in the binder
solution. The company researched use of activated carbon absorption in
an effort to remove the dye and the remaining phenol and COD in the effluent
However, this approach proved too costly when compared to a total recycle
system.
The only parameter that may interfer with an ill conditioned publicly
owned treatment works is phenol. Only certain strains of microorganisms
effectively remove phenols from waste waters and their effectiveness are
confined to narrow concentration ranges. Therefore, if sufficient dilution
water is not present, wide variations of phenol in the raw waste load may
adversely affect the populations of these organisms.
State of the Art Treatment Technology
The industry already has long realized that recirculation of chain
wash water is feasible and that a blowdown is necessary to control the
buildup of solids in the system. The industry also recognizes that suit-
able treatment of the blowdown for reuse as overspray or binder dilution
water is less costly than performing advanced treatment to a final effluent.
In the former treatment scheme the wastes essentially go into the product
and the water is evaporated. As an alternate method of blowdown disposal,
some plants because of climatic conditions or space availability have
employed evaporation ponds or spray irrigation.
39
-------
FIGURE VII
BIOLOGICAL TREATMENT AT PLANT A
Waste
Ret
v;ator
Suppl;-
\<°
Process
and
Mixing
Coagulation
and
Sedimentation
Activated
Sludge
Biological
Treatment
Suspended
Solids
Removal
Chemical
Addition
Sludge Filtrate
to Sedimentation
iC'citation
Aerobic
Di;:o:stion
iludre
A
Sludge
Filtration
Sludge
Thickeriin."
and
Conditl:ini.n.
40
-------
Table XI
Biological Treatment System
at
Plant A
Parameter Raw Waste Final Effluent Percent
mg/1 mg/1 Removal
Phenol 212 1.48 99.3
Suspended Solids 769 27 92.0
COD 6532 298 94.4
BODc 991 19.8 97.7
41
-------
The two parameters in the recycled water that limit the pressure
that can be used in the spray equipment are suspended solids and dissolved
solids. Since the latter is determined by the blowdown rate and degree
of resin polymerization it is the more difficult of the two to control.
The above methods constitute the current "state of the art treatment
technology" employed by the industry. Table XII lists the water pollution
abatement status of all existing primary plants. In summary the table
shows that 3 plants completely recycle all process waters. One more does
likewise except for cullet cooling water. Four plants recycle with three
blowing down to evaporation ponds and the fourth to a spray field. Four
plants recycle and discharge blowdown to publicly owned treatment works.
Five discharge once through waters to such works. Six plants have plans
for complete recirculation of process or all wastes streams.
All four insulation fiberglass producers operate or will shortly have
complete process water recirculation plants. Three companies now operate
total recirculation plants. Thus the entire industry has the technology
to apply the "state of the art treatment technology".
Detailed descriptions of those plants that are currently practicing
this technology follow. The plants described cover the entire range of
types of plants: new and old; small, medium and large; flame attenuation
and rotary spinning processes. The examples also illustrate how air
pollution abatement methods can affect the water system.
42
-------
Table XII
WATER POLLUTION ABATEMENT STATUS OF EXISTING
PRIMARY INSULATION FIBERGLASS PLANTS
Plant Status
A Complete recirculation of process waters. Some indirect cooling water discharge to stream
B Complete recirculation
C Discharge once-through waters to POTW. Plans for recirculation
D Complete recirculation except for discharge of cullet cooling water
E Complete recirculation of phenolic wastes by 5-1-73. Other wastes to POTW
F Complete recirculation
G Discharge once-through water to POTW. Plans for recirculation
H Recycle with blowdown to POTW, cooling waters to river. Plans for complete recirculation
I Discharge once-through waters to POTW. Recycles cullet water plans for complete recirculation (1975)
J Recycle on 1 line. Other lines discharge to river
K Recycle with blowdown to evaporation pond
L Evaporate wastes in pond
M Discharge once-through water to POTW. Plans for recirculation
N Wastes used for spray irrigation
0 Discharge to POTW
P Recycle with blowdown to evaporation ponds
Q Discharge once-through waters to POTW. Plans for recirculation
R Completely recycle phenolic waters. Caustics and other waters to POTW
S Recycle with blowdown to POTW
POTW - Publicly Owned Treatment Works
-------
Plant A
This plant was built in 1956 and currently has a production capacity
of 120,000 metric tons (270 million pounds) per year. The four rotary
spinning lines in operation are fed by direct melt, gas fueled furnaces
and employ flight conveyors in the forming area, the plant produces stan-
dard two inch insulation, acoustical ceiling tile, pipe insulation, and
blow mold.
As previously mentioned, efforts to close the water system have been
undertaken for the past thirteen years. The plant has been operating a
complete closed circuit process water loop for the past three years, but
is continuing to research more effective and economic ways of internally
treating the waste waters for reusa. Figure VIII depicts the present
system.
The company considers the crucial point in this water system to
be the huge amounts of heated air, that are drawn through the forming area
and that leave the stack saturated with water from the chain wash system.
The plant has a 1.5 percent blowdown of dirty water which stabilizes the
total solids concentration within the system to between one and two per-
cent. Phenol cencentrations range between 200 to 500 mg/1 within the
system.
The plant is currently operating stationary chain sprays at 20.4
atmospheres pressure using recycled water. Clean water is used at between
135 and 204 atmospheres when the resin buildup is particularly bad. This
flow is estimated to average 0.6 I/sec (10 gpm) and to occur over a period
of 10 minutes each shift. The dirty water sprays use 19 I/sec (300 gpm)
per machine. This plant operates its water systems at a higher total solids
concentration than other plants and must therefore use less powerful pumps
in order to protect them.
As seen from Figure VIII, the system consists of directly recycling
screened chain wash water, periodic blowdown for binder dilution water, and
chemical treatment of additional blowdown before being returned to the
recycle water system. Since a very low blowdown ratio exists, the plant
must thoroughly treat a large portion of the process water before recycling
it. The company originally employed flocculation and clarification to
remove dissolved organics and suspended solids, but has recently discontinued
flocculation without harmful effects. Sludge from the treatment systems is
landfilled at an approved state site.
Like the rest of the industry this plant is dissatisfied with the
performance and large maintenance requirements of the diatomaceous earth
filters and is investigating alternate methods such as paper filters and
cyclones.
44
-------
en
Dehumidification
Fiberglas
Manufacture
FIGURE VIII
WATER FLOW DIAGRAM OF PLANT A
A
Wash Watei
Screening
Process
Cooling
Hake-Up
T
erialization
Rat>id Mix
Floccilation
(Stopped)
Vacuum
Filtration
ClarificatiO!!
Cludpe
' Thici'.eninK
(0
>,
tn
rt
3:
JS
m
3:
O
Fresh
Water
Make-Up
1
Holdins
Sludge
,
V
-------
A considerable amount of cullet is produced here. The cullet quench
water system is a separate recirculation system with blowdown to the
flocculation treatment system. The indirect furnace cooling water system
is also closed with blowdown likewise going to the flocculation treatment
system. Chromates are used for corrosion control in the system.
Caustic mandrel cleaning is performed at this plant. However, the
volumes of caustic blowdown are such that they can be put into the wash
water recirculation system without causing obvious problems.
Air has replaced steam in the forming process thus reducing the demand
for softened waters. The only water required in this system is for indirect
cooling of the air compressors.
The majority of water used in the plant is for particulate air pollu-
tion control at the forming area. This water is also used as chain wash
water. The company is concerned that any change in the air pollution
control equipment may also effect the wash water system, particularly in
the case of where dry air pollution equipment is used and more blowdown
may be required to maintain the low solids concentration.
An air scrubber is used at the end of the curing oven to lessen the
odor problems. The system requires continual fresh water make-up due to
water evaporation and has no blowdown. A dehumidification system is used
on the forming air in a further effort to control odor problems. Contact
cooling water from this system is recycled with the blowdown going to the
chain wash water system. Noncontact once through cooling water for the
dehumidification system is discharged to a small stream behind the plant.
Unless a leak occurs in the shell and tube heat exchanger the only con-
taminant in this discharge is thermal, the temperature estimated to range
between 31 and 40 degrees Centigrade. At present this is the only plant
within the industry employing a dehumidification system.
One of the more effective techniques to curb odor problems at this
plant has been to change binder compositions to inhibit phenol volatiliza-
tion in the hot forming area. However, whenever this is done the wash
water quality must be re-evaluated to Insure its compatability with the
new binder. The company expressed concern that future air pollution abate-
ment requirements will further complicate the wash water system, but at
this time they see no reasons why the system cannot remain a total recir-
culation system.
No treatment problems can be foreseen at this and all the other
exemplary plants cited due to start-up, shut down, or process upsets.
46
-------
Plant B
This plant best represents how a new plant can avoid air and
water treatment problems through proper design before the plant is
built. The plant was completed in June of 1971, and with only two
lines has a capacity of 34,800 metric tons (75 million pounds) per
year. The plant employs rotary spinners that are fed by cold, top
feed electric melt furnaces. This technique has the advantage of
virtually eliminating the afr pollution problems encountered by con-
ventional gas fired furnaces. The electricity is three times as
expensive as the equivalent energy derived from gas. However, the
total costs are about the same since the electrodes are positioned
at the bottom of the furnace and require but one-third the energy to
melt the same amount of raw materials. Gas fired furnaces have their
burners less efficiently positioned in the furnace walls. Only standard
two inch residential insulation is produced at this plant.
Figure IX is a schematic diagram of the plant operations, and
Figure X is a detailed water flow diagram. As it can be seen the
process is identical to that at Plant A. However flocculation, using
Benoni.te clay and a polymer, and diatomite filtration is still employed,
and since the air and water treatment systems operate both efficiently
and economically, the plant has no plans to alter the system. The
plant feels that as long as the total solids concentration can be held
below two percent, the system will function properly.
47
-------
FIGURE IX
SCHEMATIC DIAGRAM OF PLANT B
**^wm
-------
Fiberglas
Manufacture
VO
FIGURE X
WATER FLOW DIAGRAM FOR PLANT B
/TV
Wash V,'ater
Screening
r-^xJi 'A
Process
Cooling
Kakc-Up
Rapid Mix
Flocc ilationi
ClarificatioA
Vacuum
Filtration
A
' Thic:-.eninK
7N
0)
H->
W
>>
CO
0)
-p
Fresh
Water
Make-Up
HoldtriR
Sludge
-------
Plant E
This plant is in the midst of installing a recirculation system
with completion expected by May 1, 1973. It is medriium sized having a
capacity of 15,900 metric tons (35 million pounds) per year. There
are four flame attenuated lines, one rotary spun Hire, and one line
which uses textile fiberglass wastes as a raw material. Standard
"residential insulation is produced by five primary lines that are fed
by gas fueled, direct melt furnaces. The plant was bought in 1952,
but the original structure is considerably older.
The water flow diagram for this plant appears as Figure XI. Except
for1 the tlowdown treatment system, the recirculatiom system, has been
successfu-Hy in operation since May 1972. The process, however, differs
considerably from those at Plants A and B.
Wire mesh chains are used in the forming area ©f the fjame attenuated
lines. The plant employs a combination of both hot .caustic washing and
13 atmospheres pressure water spray washing of the \rire mesh chains (refer
to Figure XII), The only blowdown from the caustic, ibath occurs as carry-
over water on the chain which is then washed.by the .spray wash water
system. Attempts to get away from using caustic haw.e so far not succeeded,
but the amount of caustic entering the system does mot interfer with the
binder because of the sizable dilution of wash water. The rotary spinning
line employs a flight conveyor cleaned only by a rotating water spray.
The waste textile line is a dry process.
Although drop out boxes are used with water sprays for the exiting
forming air, considerably less water is used than f®r plants A and B. .
Sufficient suspended solids are removed by the Hydrssieves and sufficient
blowdown occurs that this plant does not need to treat the recycled water
byfloccualtion and coagulation as do Plants A and B.
The blowdown system that is currently being installed consists of
pH adjustment, coagulation, settling and vacuum filtration. The treated
water will then be used as resin dilution water.
Sludge and backwash from lime softening, coolimg tower blowdown and
boiler blowdown is directed to a lagoon for settliwg. Overflow is
neutralized with sulfuric acid and discharged to a municipal sanitary
sewer. Gullet cooling water is presently discharged to the river after
large glass particles are removed in a sump.
50
-------
FIGURE XI
WATER FLOW DIAGRAM OF PLANT E
Furnaces
(Cooling)
City
Cold
Well
- "<
-
City Water
380,000 I/day
(100,000 GPD)
Pretreatment and
Lime Softening
Gullet
Cooling [__. j
Hot
Well
Cooling I
Tower
J 95,000 I/day " \/ Tank
(25,000 GPD)
Hydrasieve
Screens
Solid Wastes
Holding
Chain Spraying
V
River
Slowdown Sludge
38,000 IIday
(10,000 GPD) , +Backwash
Heating
Boilers
Lagoon
; pH Control
Publicly Owned
Treatment Works
i carryover!
4- : (
; I ^Potash
Caustic
Chain Wash
.pH Control j^j
\ Polymer ^—'
Slowdown
95,000 I/day
~,v'vi (25,000 GPD)
Treatment
Tanks
Resin Dilution
Vaccum
filters
1 I/sec.
.,(20 GPM) Dr°P out
V^ Boxes
Flight
Cleaning
¥
,4 I/sec.
;(60 GPM)
Vibrating Screen
1 I/sec.
Sump
-------
GLAS3_ •--•-:
~Inrv;_AD3 1
GAS
t FL
-Q
'
— -FIBERGLASS MAT
cn
fo
"/"•. r ' ,T' *t
• '«' *- 1 -.^i 'i
i
-ALKALINE BATH
\\v
/ 51-1DEF?
SPRAY
-;s •— ruNiVi;
f n CHAIN
h'-'GH PRESSURE
SPRAY
e
FIGURE XII
CHAIN CLEANING AT PLANT E
-------
/ .
J
Plant F
This plant best illustrates how with minimization of water usage,
most problems of the general recirculation model can be avoided. The
plant was built in 1969 with two standard insulation lines employing
marble fed, flame attenuation processes. The addition of two similar
lines in 1972 has boosted the plant from small to medium size. Current
production is 15,900 metric tons (35 million pounds) per year. The
plant has successfully maintained a complete recycle system depicted 1n
Figure XIII since it was built.
The principal reason for the system's reliability is that approxi-
mately eight percent of the process water flow is continually blown down.
This condition is able to be attained by use of low volume, high pressure
(68 atmospheres), rotating, chain (wire mesh) water sprays. The only
other water usage within the system is to flush out the dirty water pit.
The blowdown, 2 I/sec (30 gpm), is consumed in the process as overspray.
In order to protect the pumps and spray nozzles, suspended solids
are removed from the recycled water by vibrating screens, diatomaceous
earth filters, and fiberglass filters operated in series. With the com-
bination of water treatment and high blowdown rate, the total solids
concentration ranges between 0.3 and 0.5 percent. This then allows high
pressure pumps to be used, which in turn minimizes water usage and makes
the system possible. The addition of anhydrous ammonia aids the filters
1n that the ammonia inhibits polymerization of the phenols and thereby
keeps the filters free. Although this practice will raise the dissolved
solids concentration, this problem is adequately handled by the high blow-
down percentage. Even though 1t is used in the binder, additional ammonia
is automatically added to the recycled water to obtain an optimal pH of
about 9.0.
The plant also minimizes water usage by using dry air pollution
control equipment. Drop out boxes (without water sprays) are used for
the exiting forming air. High energy fiberglass filters are used for the
curing oven gases.
Maintenance of the diatomaceous earth (Per) filters has proven to be
a major cost of the system, and the plant is researching alternate treat-
ment schemes that need less attention. Flocculation is so far the most
promising technique.
Cooling tower blowdown 1s bled into the recycle system. No water
softening is required for this plant.
53
-------
Figure XIII
WATER FLOW DIAGRAM OF PLANT F
Chain
Wash
Sprays
Final
Filtered
Tank
Fiberglass
Filters
7
Clean
Water
Tank
8 I/sec
(120 gpm)
8 I/sec
(120 gpm)
7\
2 I/sec
gpm)
Slowdown to
Oversprays
Overflow
Cooling Tower
Slowdown
8-ml/sec (.05 gpm)
^T Dirty Water Pit ~~fc
V
1
V
Solid
Waste
/\
\/
Overflow
Diatomaceous Earth
£Per3_Eilt.ers
Return Line
Sluice Water
22 I/sec
(360 gpm)
Dirty Water
Side
Per Water
Side
>
Tank
-City Water
Makeup
-------
Plant G
This plant was the recipient of government research furids in 1968
in an effort to demonstrate the feasibility of complete recirculation
of chain washing waters. The project was based upon three principles.
First, the caustic baths used to clean the forming chains could be
replaced by high pressure water sprays. Secondary diatomite filtration
would prevent spray nozzle plugging. Last, the entire blowdown from
the system could be used as overspray. Figure XIV illustrates the
process water system.
The plant is an older, small sized plant producing pipe insulation.
As such a simpler binder mixture is used than for standard two inch
insulation, and fewer problems are encountered in recyling the waters.
The recycle system operates between 0.1 and 0.5 percent total solids.
Several items have changed since the research grant. The diatomite
filters have not proven to be as successful as originally thought, since
excessive maintenance is required. The company has subsequently decided
to replace these filters with a screening and clarification system. The
research report also included anticipated resin savings into the systems
costs. Although the recycled phenols do display some binding properties,
they are not as significant as first assumed.
Additional pipes discharging process waters have been discovered
since the research project, and have been subsequently incorporated into
the treatment system. The remaining discharges have been diverted to
a sanitary sewer.
55
-------
1 I T I 111
Figure XIV - FLOW CHART - FOR
PLANT G
56
-------
Plant D
This plant is currently experiencing the most difficult problems
within the industry in maintaining a completely closed cycle water
system, and as such serves as an example that, with even minimal
internal waste water treatment, a closed water loop can be operated.
In 1965 the plant was bought from a company who also produced fiber-
glass. The structure was originally built in 1961. In September 1970
the company was given a cease and desist order by the State Water
Pollution Control Board and since that time the plant in order to comply
has operated the system shown in Figure XV. The plant is medium sized
and produces no specialty products. There are two lines employing
rotary spinners and direct melt, gar. fueled furnaces.
At the heart of the treatment system there are two 25,000 liter
(6500 gallon) sumps, one for each line. Wash water passes through 40
mesh screens and receives approximately five minutes retention time in
the sumps before the water Is again used to clean the fight conveyor.
Relatively low pressures are used to clean the flight conveyors, 5.8
atmospheres.
A small amount of water is pumped from the sumps to two 38,000
liter (10,000 gallon) tanks for additional settling. Sludge is then
pumped to a 19,000 liter (5,000 gallon) tank to hold until it is hauled
away to a landfill. The plant 1s able to keep the total solids in as
little control that exists by blowing down 98,000 and 57,000 liters
(26,000 and 15,000 gallons) per day respectively as overspray and binder
dilution water.
Because the preliminary screening is inadequate and the water 1n the
sump is corstantly stirred up due to the short retention time, quite a
bit of foaning occurs. So much foaming occurs that it eventually floats
and harden; to a depth of about two feet, necessitating "digging out" the
sumps once a week. The foam is about one-half resin and one-half glass
fibers. While this is being done, both lines must be shut down for a
period of 10 to 12 hours. In addition the flight conveyors must also be
blasted with crushed walnut shells to free them of polymerized resin.
Walnut shells are used to minimize chain wear. Despite the lost time in
production and high maintenance costs, the plant is still able to make
some profit.
The company will by the autumn of 1973 install automatic, chain
driven scrappers in both sumps and reposition the existing screens for
easier access to the sumps. In addition the plant will treat a portion
of the recycled water by flocculation much like plants A and B. However,
57
-------
FIGURE XV
WATER FLOW DIAGRAM OF PLANT D
Softener Backwash,
Miscellaneous Waters
City Makeup
95,000 1PD
(25,000 GPD)
City Water
Gullet
Cooling
River
76,000 - 680,000 1PD
(20,000 - 180,000 GPD)
Solid Waste
Solid
Waste
40 Mesh
Screens
A
Solid Wastes
\/v \|A!/
25,000 I
(6,500 Gal)
SUMP
Chain + Hood
Washing
80 I/sec
(1,200 gpm)
A
"Air Pollution
Expansion
Chamber
Sprays
Supernatent
^•v
<^
v.
1 J\
19,000 1
(5,000 Gal)
Tank
Sludge
Sludge (Treatment
\
(1
/
38,000 1
0,000 Gal)
Tank
System Ident
V
Binder
Dilution
(15,000 GPD)
V
For Other Line)
Overspray
1 I/sec
(18gpm )
-------
K>,
it Is not known at this time what percentage of the recycled v ater
flow will be so treated, and 1t is conceivable that this will be as
high as 100 percent. The plant expects to profit from the 1n:tallation
of treatment facilities since more than enough increased production will
result as to pay for the treatment.
Because the recycled water currently has a total solids concentration
of 4 percent (ninety percent of which are dissolved organlcs) the air
pollution control equipment employing water sprays is ineffective. Like
other plants, it is estimated that the total solids should be less than
two percent In order to keep these water and air systems 1n control.
Except for oillet cooling water all waste waters are sent to the
sumps. The former is discharged to a stream without adequate treatment.
Summary
In summary the proceeding examples Illustrate the following points.
1. The type of fiberizing process has no appreciable effect upon
the treatability of the wastes in a recycle system.
2. High pressure sprays (67 atmospheres) can effectively clean the
forming chain if sufficient treatment of the recycled.water 1s
provided as to avoid damage to the puraps, pipes, anc spray
nozzles.
3. Smaller volumes of water can be used at the higher fressures.
4. The size of the plant has no effect upon the treatalility of the
wastes in a recycle system.
5. The age of a plant does affect the efficiency of a recycle system
in that in the design of a new plant minor changes n the process
will significantly improve the treatability of the uaste waters.
6. Although recycled phenols do have some binding capabilities they
are not such as to cause a significant reduction in the amount
of new binder made up.
59
-------
7. The treatment systems described operate within critical limits
of total solids concentrations. New binder formulations and
additional wet air pollution control equipment may necessitate
significant changes in the recycle system requiring external
blowdown as an interim measure.
8. Using properly treated blowdown for overspray or binder
dilution water will not affect the quality of the product.
60
-------
SECTION VIII
COST, ENERGY AND NON-WATER QUALITY ASPECTS
Cost Reduction Benefits of Alternate Treatment and
Control Techno!ogle's"
The three alternate treatment and control technologies considered are.
biological treatment, biological treatment and carbon" adsorption, and
complete recycle. . All three treatment schemes consist of recycling chain
wash water and treatment of only the blowdown. Consideration of treat-
ment of once through process water has lo.ng since been abandoned by the
industry bec.ause of the large volumes involved and the amenability of
chain wash water to treatment for recycle.
Table XIII compares the costs and effluent qualities for the three
alternate treatment schemes as they are estimated for Plant A. The
table clearly indicates that total recycle is the best alternative of
the three treatment schemes for best practicable control technology
currently available, best available technology economically achievable,
and best available demonstrated control technology. It is here assumed
that the relationship between the costs of the three alternatives will
hold for different plant sizes. Even if this were not true, it is quite
significant that no discharge of pollutants can be achieved at costs com-
parable to end of pipe treatment technology.
Furthermore best available technology economically achievable specifies
application of technology "which will result in reasonable further progress
toward the national goal of eliminating the discharge of all pollutants".
Total recycle both is economically achievable and meets the no discharge
of pollutants goal. Any end-of-pipe treatment that is installed to meet
best practicable control technology currently avialable may not be readily
convertable to meet best available technology economically achievable require-
ments. 'This and the fact that total recycle is practicable and currently
available constitute the reasons for the proposed treatment and control
technology recommendations.
Cost of Total Recycle
Table XIV summarizes the v/ater pollution abatement costs for a few
insulation fiberglass plants. Investment .costs have been interpolated
to August 1971 dollars by using EPA tables of sewage treatment plant
cost indexes. (14) Two depreciation periods are used in calculating
61
-------
TABLE XIII
A COMPARISON BETWEEN THE ALTERNATE TREATMENT
AND CONTROL TECHNOLOGIES
Capital Costs ($1000)
Annual "Operating Costs ($100)
Effluent Quality
1
COD (mg/1)
Phenol (mg/1 )
Suspended Solids (mg/1)
Color
Extended
Aeration
1100
540
20
298
1.48
27
yes
ExteiKied
Aerati on
Hh
Activated
Carbon
1260
556
> 102
>502
>0.052
>52
no
Total
Recycle
745
508.5
03
O3
O3
O3
no
1-. Operating and maintenance costs and power costs for extended aeration
and activated carbon are assumed to be the same for the total recycle
system.
2. Estimated
3. No discharge hence no pollutants.
62
-------
en
u>
TABLE XIV
WATER POLLUTION ABATEMENT COSTS FOR TOTAL RECYCLE
Plant
E F F3 6
Capacity (Thousand Metric Tons/Yr.) 16.9 9 16 9
(Million Pounds/yr.) 35 20 35 20
Investment1 ($1000) 483 32.5 340.5 245.4
Annual Costs
Capital Costs ($1000) 2
Depreciation ($1000) 24 23.7 17.5
Years Amortization 20 14 14
Operating and Maintenance ($1000) 55 36.5 44.5 13.8
Energy and Power Costs ($1000) 8 1.7 2.3 4.6
Total Annual Cost ($1000) 89 62 36
Adjusted Annual Cost2 ($1000) 113 71 81 43
Energy Consumption (1000 kilowatt-hours/yr.) 551 165.8 212 512
1 Adjusted to Auqust 1971 dollars using sewage treatment plant cost index (14).
2 Total Annual Cost using a 10 year amortization period.
3 After 1972 expansion to 4 lines, includes original oversized treatment system.
-------
total annual cost. The first is the true depreciation period as deter-
mined by the company. For the second, a 10 year depreciation is used
for the purposes of comparison with the consultant study summarized
later.
An economic study by one consultant (11) concluded that zero dis-
charge is practical for the insulation fiberglass industry. The firm
selected two basic forms of recycle systems. Treatment A, coarse filtra-
tion, fine filtration and water recycle is practiced at Plant F. Treatment
B, coarse filtration, flocculation, settling and water recycle, is practiced
at Plant B. Table XV lists the resultant fixed capital investment and
annual operating costs for the two treatment schemes scaled to the four
plant sizes considered by the consultant.
As a conservative estimate 80 percent production was used to
calculate incremental capital and operating costs as shown in Table XVI.
Assumed selling prices and estimated current fixed capital investments
were used. Table XVI and Figure XVI both clearly show that the incremental
operating costs for the treatment systems are not linealy related to plant
size. Therefore, the smaller plants will spend more per unit of product
in order to maintain a closed water system than larger plants.
The relative effects on company and plant pretax earnings, assuming
no price increases as a result of the incremental operating costs, will
be equal to the proportion of selling price represented by these costs.
If incremental costs are passed on, the current rate of profitability
will be maintained. As current returns on investment are unknown for
individual plants, the relative effects on returns on investment can only
be obtained by assuming a certian level of profits on sales before taxes,
and measuring sensitivity at various levels of returns on investment.
For this analysis, average pretax earnings are assumed to be 12 per-
cent on sales for wool glass fibers. The current returns on investments
tested are 5, 10, and 15 percent in Table XVII. Thus for wool glass, a
1 percent increase in operating costs will reduce returns on investments
by 8.3 percent of the current rate.
Plants of any size that currently have a return on investment no better
than 5 percent will become marginal and could possibly cease production.
However, no such facilities currently exist. Plants operating at over 5
percent return on investment will continue to enjoy reasonable returns.
It is estimated that $10 million is needed for the industry to achieve
no discharge, assuming that there are presently no treatment facilities.
The consultant concluded that the insulation fiberglass industry has the
64
-------
TABLE XV
ESTIMATED COST OF WASTE WATER TREATMENT FOR
INSULATION FIBERGLASS MANUFACTURE (11)
Type Treatment System
Plant
Capaci ty
Thousand Million
metric Ib/yr
tons/yr.
Coarse Filtration
Fine Filtration
Water Recycle
Coarse Filtration
Flocculation
Settling
Water Recycle
200
41
9
2.3
400 Fixed Cap, Investment ($1000) 2000
Annual Operating Cost $1000) 610
90 Fixed Cap. Investment ($1000) 800
Annual Operating Cost ($1000) 200
20 Fixed Cap. Investment ($1000) 3251
Annual Operating Cost ($1000) 80
5 Fixed Cap. Investment ($1000) 150
Annual Operating Cost ($1000) 46
1050
680
400
^
2003
160
71
70
37
1. Based on Costs reported by the Industry
2. Actual investment was closer to $600,000 but the existing sysiem has more
capacity than required.
3. Reported cost was closer to 0.3^/lb., but reported treatment (hemical cost
seems high.
65
-------
TABLE XVI
SUMMARY OF CAPITAL AND OPERATING COST EFFECTS:
*
Plant Plant
(Capacity Output Net Revenues
M metric (MM Ib) Type of Treatment Process (MM Ib) ($MM)
ton
200 440 (A) Coarse and Fine **
Filtration 352 98'. 5
(B) Elocgulation and
Settling 352 98.5
41. 90 CA) 72 18.7***
(B) 72 18.7
9 -.0 (A) 16 4.4**
(B) 16 4.4
****
2t3 5 (A) 4 1.2
(B) 4 1.2
WOOL GLASS FIBER
Current Fixed
Capital Incremental
Investment ' Investment
(SMM) ($MM)
80
80
26
26
10
10
4
4
* @ 80% Yield
** @ 28c/lb !
<*» @ 26c/lb Table reproduced from "Initial Economic Impact Analysis
"* **** Pollution Control Costs Upon th* ?ihpr Glass Tnrtit««-rv" \
@ 30c/lb
2.0
1.0
0.8
0.4
0.325
0.16
0.15
0.07
of Water
Water
Incremental
Investment
as % of
Current
Investment
2.5
1.25
3.8
1.9
3.25
1.6
3.75
1.75
1 t
Pollution Control
Incremental
Operating
Cost
(C/lb)
0.18
0.19
0.27
0.29
0.50
0.44
1.15
0.93
Costs
Incremental
Operating Cost
as X of Selling
Price
0.64
0.68
1.04
1.11
1.78
1.57
3.83
3.10
-------
TABLE XVII
EFFECTS ON RETURNS ON INVESTMENT
WOOL GLASS FIBER (11)
Plant Size
Capaci ty
v{M metric Waste Water
tons/yr) Treatment Type
200 A
B
41 A
B
9 A
B
2.3 A
B
Operating Cost
as % of
Selling Price
.64
.68
1.04
1.11
1.78
1.57
3.83
3.10
Predicted affect on
return on investment
if currently at
5%
4.7
4.7
4.6
4.5
4.3
4.4
3.4
3.7
102
9.5
9.5
9.2
9.1
8.5
8.7
6.8
7.4
15%
14.2
14.2
13.7
13.6
12.8
13.0
10.2
11.1
67
-------
financial capabilities to install total recycle facilities, and that
this will have minimal effect on the selling price of its products.
The economic analysis of the consultant report was based upon
treatment systems employed at only two plants of different companies.
Figures XVII and XVIII compare the costs of water treatment for different
sizes of plants as determined from actual industry calculations and the
estimations by the consultant previously mentioned. As seen, actual
costs lie within the limits estimated by the consultant report, and it
can be assumed that the conclusions of the consultant study hold true
for the entire insulation fiberglass industry.
68
-------
FIGURE XVI
EFFECT OF PLANT SIZE ON COST OF WATER
RECYCLING IN WOOL PLANTS (11)
o
60
o
cn
UD
H
CO
O
o
e>
25
w
P-I
o
2.0*
.5
1.0*
0.5-
-.1
0.2--
0.1
(10)
10
(100)
100
(1000)
Plant Capacity (Million lb/yr)
Thousand Metric tons/yr
-------
FIGURE XVII
INVESTMENT COSTS VERSUS PLANT SIZE
2000-
1000-
I
-n
U Treatment System A, from Table XV.
A Treatment Svetem B, from Table XV
G Industry Data
Pla^t Size (Thousands of Metric Tons/Yr)
-------
i <•
. ! . i
EJ Treatment
.
A1 Treitnienjt Systen
O' Iad\istkyl DAta
• ' • ! '
Plant.Size (Thousands of Metric Tons/Yr.)
-------
Non-Water Pollution Effects of the Closed Treatment System
The major non-water quality aspect that has resulted from existing
closed water systems have been solid waste disposal. Sources of solid
wastes include cullet, glass fiber - resin sludges, particulates removed
from stack gases, and wasted product. Since all of these solids are in
a form not currently usable, they are hauled to sanitary landfills.
Restrictions at some sites prohibits burial of phenolic wastes because .
of the fear of ground water contamination. One company proposes to auto?-
clave its sludges to insure complete polymerization of the phenols.
In only one case has use of recycled water affected air emissions
(Plant D). In this case chain wash water is also used in the drop out
boxes for the forming air. However, the plant will soon be installing
additional water treatment equipment which will correct the problem.
The use of high pressure spray water pumps does produce objectionable
levels of noise. However, a fiberglass plant is extremely noisy especially
in the forming area. The small increment of additional noise introduced
by pumps and other miscellaneous recycle equipment would not affect the
hearing protection measures already practiced by the industry.
This type of treatment system does affect land requirements. The
treatment systems employed at Plants A and B and proposed at Plant D re-
quire considerable space for flocculating and settling tanks, since low
pressure, high volume wash systems are used. Although the high pressure
low volume wash systems require space for overflow ponds it is not as
great as in the previous case.
Power requirements of existing treatment systems are included in
Table XIV. The industry considers the extra power needed to operate
waster treatment systems to be negligible when compared to the power
requirements of the fiberglass manufacturing equipment.
72
-------
SECTION IX
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION
OF THE BEST PRACTICABLE CONTROL TECHNOLOGY CURRENTLY
AVAILABLE — EFFLUENT LIMITATIONS GUIDELINES
Introduction
The effluent limitations which must be achieved July 1, 1977 are
to specify the degree of effluent reduction attainable through the
application of the best practicable control technology currently avail-
able. This technology is generally based upon the average of the best
existing performance by plants of various sizes, ages and unit processes
within the industrial category and/or subcategory industry. This average
is not based upon a broad range of plants within the insulation fiberglass
manufacturing industry, but based upon performance levels 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 processes 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 require-
ments).
Best practicable control technology currently available emphasizes
treatment facilities at the end of a manufacturing process but includes
the control technology within the process itself when the latter are con-
sidered to be normal practice within an industry.
A further consideration is the degree of economic and engineering
reliability which must be established for the technology to be "currently
available." As a result of demonstration projects, pilot plants and
general use, there must exist a high degree of confidence in the engineer-
ing and economic practicability of the technology at the time of commence-
ment of construction or installation of the control facilities.
mm: THESE UK
SU2J2C7 TO GUS3B BASES i!PKi 62S-:.:.3
73
-------
DRAFT
Effluent Reduction Attainable Through The Application of Best
Practicable Control Technology Currently Available
Based upon the information contained in Sections III through VIII
of this report, a determination has been made that the degree of effluent
reduction attainable through the application of the best practicable
control technology currently available is no discharge of process waste
water to navigable waters. •
Identification of Best Practicable Control Technology Currently Available
Best practicable control technology currently available for the
insulation fiberglass manufacturing subcategory is recycle and reuse of
process waters within the operation.- To implement this require:
1. Replacement of caustic baths with pressurized water sprays 1n
order to clean forming chains of glass fiber and resin. This
has already been accomplished by the industry.
2. The higher the pressures are, the better the cleaning results.
This results in minimizing the use of other cleaning methods
and in the design of smaller treatment systems, since less water
is used,
3. Reuse of chain wash water after suitable treatment.
4. Slowdown from the chain wash system to control dissolved solids
disposed of in the process as overspray, binder dilution water,
or extra - process by evaporation and/or spray irrigation.
5. Incorporation of hood wash water into the chain wash system.
6. Incorporation of other miscellaneous process waters, such as
mandrel cleaning caustic, into the chain wash system.
7. Recirculation of cullet cooling water with blowdown to the chain
wash recirculation system.
8. Incorporation of all non-process contaminated waste streams into
the chain wash recirculation system. These streams include floor
wash water and storm water that falls upon specific areas where
phenol contamination occurs.
The amounts and concentrations of dissolved solids in water softener
backwash and boiler blowdown and the extensive treatment required to remove
dissolved solids from such do not justify the treatment of these wastes.
SUBJECT 10 CiJAiiEiS SASi^ w«- - »-•-• -.-••--. ..- v ;....a.uii- au.tea M E^A,
74
-------
Rationale for the Selection of Best Practicable Control Technology
Currently Available
Age and Size of Equipment and Facilities
As set forth in this report, industry competition and general
improvements in production concepts have hastened modernization of
plant facilities throughout the industry. This coupled with the
similarities of waste v/ater characteristics for plants of varying
size substantiate that total recycle is practicable.
Total Cost of Application in Relation to Effluent Reduction Benefits
Based upon the information contained in Section VIII and Supple-
ment A of this report, the industry as a whole would have to invest
up to an estimated maximum of $10,000,000 to achieve the effluent
limitations prescribed herein. This amounts to approximately a 1.0
to 4.0 percent increase in projected total capital investment, and an
anticipated increase of 0.6 to 3.8 percent in the operating cost.
It is concluded that the ultimate reduction to zero discharge
outweighs the costs. 37 percent of plants are achieving no discharge
of pollutants. Only three plants (16 percent) still discharge process
waters to surface waters, and to these plants no discharge of pollutants
can be practically applied.
Processes Employed
All plants in the industry use the same or similar production
methods, the discharges from which are also similar. There is no
evidence that operation of any current process or subprocess will
substantially affect capabilities to implement best practicable con-
trol 'technology currently available.
Engineering Aspects of Control Technique Applications
This level of technology is practicable because 37 percent of the
plants in the industry are now achieving the effluent reductions set
forth herein. The concepts are proved, available for implementation,
enhance production and waste management methods may be readily adopted
through adaptation or modification of existing production units.
Process Changes
This technology is as an integral part of the whole waste management
program now being implemented within the industry. While it does require
inprocess changes, they are practiced by many plants in the industry.
!'•;.* ;.:ro' r osi
• ic»|irv *'Y '^:['
75
-------
DRAFT
Non-Water Quality Environmental Impact
There is one essential impact upon major non-water elements of
the environment: a potential effect on soil systems due to strong
reliance upon the land for ultimate disposition of final effluents.
With respect to this, it is addressed only in a precautionary
context since no evidence has been discovered which even intimates
a direct impact—all evidence points to the contrary. Technology
and knowledge are available to assure land disposal or irrigation
systems are maintained commensurate with crop need or soil tolerance,
76
-------
SECTION X
EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF THE BEST
AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE - EFFLUENT LIMITATIONS
GUIDELINES
The effluents limitations reflecting this technology is no discharge
of process waste waters to navigable waters as developed in Section IX,
ESS A8E TtKW.
BHfiiSiES SASSrj
77
-------
SECTION XI
NEW SOURCE PERFORMANCE STANDARDS
The effluents limitations for new sources 1n no discharge of process.
waste waters to navigable waters as developed in Section IX.
• , ." TV,I3 REPORT ii'i.B
10T1GE: TBESEr'r-"-'. • ' - " A
' TO •--- ^"-*B
-------
Section XIV
BIBLIOGRAPHY
1. Encyclopedia Brltannica, "Glass Fibers," Volume 10, William
Benton, Publisher, Chicago, PP. 475-476.
2. Phillips, C. J., "Fiber Glass," The Encyclopedia Americana
Volume 6, Americana Corporation, New York,PP. T70-T70b.
3. Shreve, R. Horn's, Chemical Process Industries, 3rd edition,
McGraw-Hill Book Company, New York, PP. 700-702, (1967).
4. Shand, E. B., Glass Engineering Handbook. 2nd edition, McGraw-Hill
Book Company, New York, PP. 375-410, (1958).
5. Phenolic Haste Reuse by Diatomite Filtration, Johns-Manville
Products Corporation, Water Pollution Control Research Report,
federal grant number 12080 EZF (September, 1970).
6. Baloga, J.M., Hutto, F.B., Jr., and Merrill, E.I.,- "A Solution
To The Phenolic Pollution Problem In Fiber Glass Plants: A
Progress Report," Chemical Engineering Progress Symposium Series,
American Institute of Chemical Engineers, Number 97, Volume 65,
PP. 124-127. (1968).
7. Angelbeck, Donald L., Reed, Walter B., and Thomas, Samuel H.,
"Development and Operation of a Closed Industrial Waste Water
System," Owens-Corning Fiberglass Corporation Paper Presented
at the Purdue Industrial Waste Conference, Purdue University.
West Laffayette, Indiana, (May 4, 1971).
8. Fletcher, George W., Thomas, Samuel H., and Cross, Donald E.,
"Development and Operation of a Closed Wastewater System For
The Fiberglas Industry," Owens-Corning Flberglas Corporation,
Paper Presented at the 45th Annual Conference, Water Pollution
Control Federation, Atlanta, Georgia, (October 9, 1972).
9. "Welcome to Owens-Corning Fiberglas...A citizen of Newark, Ohio,"
Owens-Corning Fiberglas Corporation.
10. Helbring, Clarence H., et al, "Plant Effluent - Recycle and
Reuse, PPG Industries, Works #50, Shelbyville, Indiana, "PPG
Industries, A Paper Presented at the Purdue Industrial Waste
Conference, Purdue University, West Laffayette, Indiana, (1971).
83
-------
11. "Initial Economic Impact Analysis of Water Pollution Control Costs
Upon The Fiber Glass Industry," report to Environmental Protection
Agency by Arthur D. Little, Inc., Cambridge, Massachusetts,
Contract No. 68-01-0767, (1973).
12. Standard Methods for the Examination of Water and Wastewater, 13th
edition, American Public Health Association, Washington, D.C. (1971).
13. "Methods for Chemical Analysis of Water and Wastes," Environmental
Protection Agency, National Environmental Research Center, Analytical
Quality Control Laboratory, Cincinnati, Ohio (1971).
14. "Sewage Treatment Plant and Sewer Construction Cost Indexes,"
Environmental Protection Agency, Office of Water Programs Operations,
Municipal Waste Water Systems Division, Evaluation and Resource
Control Branch.
84
-------
SECTION XV
GLOSSARY
Act
The Federal Water Pollution Control Act Amendments of 1972.
Atmosphere
Unit of pressure. One atmosphere is normal atmosphere pressure.
Batt
Standard wool mat used for residential insulation.
Best Available Technology Economically Achievable (BATEA)
Treatment required by July 1, 1983 for industrial discharges to surface
waters as defined by Section 301 (b)(2)(A) of the Act.
Best Prac:icable Control Technology Currently Available (BPCTCA)
Treatment required by July 1, 1977 for industrial discharges to surface
waters as defined by Section 301(b)(l)(A) of the Act.
Best Available Demonstrated Control Technology (BADCT)
Treatment required for new sources as defined by Section 306 of the Act.
Binder
Chemical substance sprayed on the glass fibers in order to bond them
together. Synonymous with the terms resin and phenolic resin.
BOD, 5 day, 20°C
Biochemical Oxygen Demand.
Borosilicate
A type of glass containing approximately five percent boric oxide.
Capital Costs
Financial charges which are computed as the cost of capital times the
capital expenditures for pollution control. The cost of capital 1s
based upon a weighed average of the separate costs of debt and equity.
85
-------
Category _a_n_dSubcategory
Divisions of a particular industry which possess different traits which
affect water quality and treatabllity.
Caustic
Any strongly alkaline material. Usually sodium hydroxide.
Chain
A revolving metal belt upon which the newly formed glass fibers fall
to form a thick mat. There are two general types of chains: wire
mesh chains and flight conveyors. The latter are hinged metal plates
with several holes to facilitate the passage of air.
cm
Centimeter
COD
Chemical Oxygen Demand
Gullet
Chunks of solid glass formed when molten glass bled from a furnace comes
into contact with water.
Curi ng
The act of thermally polymerizing the resin onto the glass fibers in a
controlled manner.
Depreciation
Accounting charges reflecting the deterioration of a capital asset over
its useful life.
Diatomaceous Earth
A filter media used in this case to remove fine glass-resin particles.
The process of filtration is referred to as diatomite filtration.
Dry Air Pollution Control
The technique of air pollution abatement without the use oi water.
86
-------
Fiberglass
Extremely fine fibers of corrosion resistant glass of diameters typically
less than 0.015 mm. Also fiber glass.
Flame Attenuation
The glass fiber forming process in which thick threads of glass are
forced through perforated bushings and then attenuated by burning
gases or steam in order to further reduce the fiber diameters.
Forming Area
The physical area in which glass fibers are formed, sprayed with
lubricant and/or binder, and fall to the chain, A downward forced
air draft is maintained to insure proper binder dispersal and to
force the fibers to the chain.
Glass Wool
The cured fiberglass - resin product. Also referred to as insulation
fiberglass.
Gallons per minute
Industrial Waste
All wastes streams within a plant. Included are contact and non-contact
waters. Not included are wastes typically considered to be sanitary
wastes .
Investment Costs
The capital expenditures required to bring thee treatment or control
technology into operation. These include the traditional expenditures
such as design; purchase of land and materials; site preparation; con-
struction and Installation; etc.; plus any additional expenses required
to bring the technology into operation including expenditures to establish
related necessary solid waste disposal.
1
Liter
Lubricant
Usually a mineral oil added to the binder to inhibit fiber abrasion.
87
-------
M
Thousand (e.g. thousand metric tons).
Mandrel
A pipe-like metal form with numerous holes. Serves as a form about
which insulation is shaped to make pipe insulation.
Mat
The newly formed layer of fiberglass on the chain.
mg/1
Milligrams per liter. Nearly equivalent to parts per million
concentration.
Million (e.g. million pounds)
New Source
Any building, structure, facility, or installation from which there
is or may be a discharge of pollutants and whose construction is
commenced after the publication of the proposed regulations.
No Discharge of Pollutants
No net increase (or detectable gross concentration if the situation
dictates) of any parameter designated as a pollutant to the accuracy
that can be determined from the designated analytical method;.
Operations and Maintenance
Costs required to operate and maintain pollution abatement equipment.
They include labor, material, insurance, taxes, solid waste disposal
etc.
Overspray
Wator spray applied to the newly formed glass fibers, the purpose of
which is to both cool the hot glass and to decrease the rate of resin
volatilization and polymerization.
88
-------
Pack
A fiberglass product made from relatively thick fibers, as compared
to glass wool insulation, that is used for special application (e.g.
air filters and distillation column packing).
A measure of the relative acidity or alkalinity of water. A pH of 7.0
indicates a neutral condition. A greater pH indicates alkalinty and
a lower pH indicates acidity. A one unit change in pH indicates a 10
fold change in acidity and alkalinity.
Phenol
Class of cyclic organic derivatives with the basic formula CgHgOH
Pr_e treatment
Treatment proved prior to discharge to a publicly owned treatment works.
Process Water
(i) Any water which comes into contact with any glass, fiberglass,
phenolic binder solutions or any other raw materials, intermediate
or final material or product, used in or resulting from the manufacture
of insulation fiberglass, (ii) Non-contact cooling water.
Resin
Synonymous to Binder
Rotary Spun
The glass fiber forming process in which glass is forced out of holes
in the cylindrical wall of a spinner.
Sec
Second. Unit of time.
Secondary Treatment
Biological treatment provided beyond primary clarification.
Silicates
A chemical compound containing silicon, oxygen, and one or more metals.
89
-------
Staple Fiber
Glass fibers with used short irregular lengths for insulation products
in contrast to continuous filaments used for textile products.
Surface Haters
Navigable waters. The waters of the United States including the
territorial seas.
Wet Air Pollution Control
The technique of air pollution abatement utilizing water as an
absorptive media.
90
-------
56* "*"*
MJLTIPLY (ENGLISH UNITS)
ENGLISH UNIT
ABBREVIATION
TABLE XVIII
CONVERSION TABLE
by
CONVERSION ABBREVIATION
acre
acre - feet
British Thermal Unit
British Thermal Unit/pound
cubic feet/minute
cubic feet/second
cubic feet
cubic feet
cubic Inches
degree Fahrenheit
feet
gallon
gallon/minute
horsepower
inches
Inches of mercury
pounds
million gallons/day
mile
pound/square inch (gauge)
square feet
square Inches
tons (short)
yard
ac
ac ft
BTU
BTU/lb
cfm
cfs
cu ft
cu ft
cu in
"F
ft
gal
gpm
hp
In
in Kg
Ib
mgd
mi
psig
sq ft
sq In
t
y
0.405
1233.5
0.252
0.555
0.028
1.7
0.028
28.32
16.39
0.555CF-32)1
0.3048
3.785
0.0631
0.7457
2.54
0.03342
0.454
3,785
1.609
(0.06805 psig +1)1
0.0929
6.452
0.907
0.9144
ha
cu m
kg cal
kg cal/kg
cu m/m1n
cu m/mln
cu m
1
cu cm
«c
m
1
I/sec
kw
cm
atm
kg
cu n/day
km
atm
sq m
sq cm
kkg
m
TO OBTAIN (METRIC UNITS)
METRIC UNIT
hectares
cubic meters
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
cubic meters/day
kilometer
atmospheres (absolute)
square meters
square centimeters
metric tons (1000 kilograms)
meters
Actual conversion, not a multiplier
91
------- |