August 1995
POLLUTION PREVENTION OPPORTUNITY ASSESSMENT
UNITED STATES NAVAL BASE NORFOLK
NAVAL AIR STATION
by
D. Bowman, J. DeWaters, J. Smith, and S. Snow
TRC Environmental Corporation
and
R. Thomas
Lockheed Environmental Systems & Technologies Company
Las Vegas, Nevada 89119
EPA Contract No. 68-D2-0181
Work Assignment 1/011
and
EPA Contract No. 68-C4-0020
Project Officer:
Kenneth R. Stone
Office of Research and Development
National Risk Management Research Laboratory
Cincinnati, Ohio 45268
NATIONAL RISK MANAGEMENT RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
-------
DISCLAIMER
The information in this document has been funded wholly or in part by the United States Environmental
Protection Agency under Contract 68-D2-0181 to TRC Environmental Corporation and Contract 68-C4-0200 to
Lockheed Environmental Systems & Technologies Company. It has not been subjected to the Agency's peer and
administrative review, and it has not been approved for publication as an EPA document. Mention of trade names or
commercial products does not constitute endorsement or recommendation for use.
-------
FOREWORD
The U.S. Environmental Protection Agency is charged by Congress with protecting the Nation's land,
air, and water resources. Under a mandate of national environmental laws, the Agency strives to formulate
and implement actions leading to a compatible balance between human activities and the ability of natural
systems to support and nurture life. To meet this mandate, EPA's research program is providing data and
technical support for solving environmental problems today and building a science knowledge base necessary
to manage our ecological resources wisely, understand how pollutants affect our health, and prevent or reduce
environmental risks in the future.
1 The National Risk Management Research Laboratory is the Agency's center for investigation of
technological and management approaches for reducing risks from threats to human health and the
environment. The focus of the Laboratory's research program is on methods for the prevention and control of
pollution to air, land, water and subsurface resources; protection of water quality in public water systems ;
remediation of contaminated sites and ground water; and prevention and control of indoor air pollution. The
goal of this research effort is to catalyze development and implementation of innovative, cbst-effective
environmental technologies; develop scientific and engineering information needed by EPA to support
regulatory and policy decisions; and provide technical support and information transfer to ensure effective
implementation of environmental regulations and strategies.
This publication has been produced as part of the Laboratory's strategic long-term research plan. It is
published and made available by EPA's Office of Research and Development to assist the user community
and to link researchers with their clients.
E. Timothy Oppelt, Director
National Risk Management Research Laboratory
-------
ABSTRACT
This report summarizes work conducted at the U.S. Navy's Naval Base Norfolk, Naval Air Station (NAS)
located at Sewells Point in Norfolk, Virginia, under the U.S. Environmental Protection Agency's (EPA) Waste
Reduction Evaluations at Federal Sites (WREAFS) Program. This project was funded by the EPA and conducted in
cooperation with U. S. Navy officials.
The purposes of the WREAFS Program are to identify new technologies and techniques for reducing wastes from
process operations and other activities at Federal sites, and to enhance the implementation of pollution prevention/waste
minimization through technology transfer. New techniques and technologies for reducing waste generation are identified
through waste minimization opportunity assessments and may be evaluated further through joint research, development,
and demonstration projects.
Additional support for this Pollution Prevention Opportunity Assessment (PPOA) was provided by the Strategic
Environmental Research and Development Program (SERDP), which is a cooperative effort between the DOD, DOE,
and EPA to develop environmental solutions to enhance mission readiness.
Under the Chesapeake Bay Agreement, Naval Base Norfolk is a member of the Tidewater Interagency Pollution
Prevention Program (TIPPP). At Norfolk, the Navy and the EPA have evaluated techniques and technologies to reduce
waste generation from cooling tower operations. A PPOA was conducted at the Norfolk Naval Air Station in June 1994
which identified areas for waste reduction during operation and maintenance of the NAS cooling towers. The study
followed procedures outlined in the EPA's Facility Pollution Prevention Guide. Opportunities were identified for
reducing the generation of waste from cooling tower water treatment operations. Changes in operational and treatment
processes and procedures have been evaluated for their potential to achieye pollution prevention objectives. The options
have been studied for technical and economic feasibility, and are summarized in this report.
This report was submitted in fulfillment of Contract Number 68-D2-0181 by TRC Environmental Corporation,
under the sponsorship of the U.S. Environmental Protection Agency. This report covers the period from 20 June to 30
September 1994. Work was completed as of 30 September 1994.
This report was edited and completed by Lockheed Environmental Systems & Technologies Company under
Contract Number 68-C4-0020.
IV
-------
CONTENTS
Section Page
DISCLAIMER ii
FOREWORD iii
ABSTRACT iv
FIGURES i vii
TABLES - -: vii
ABBREVIATIONS viii
ACKNOWLEDGEMENTS : ix
1 INTRODUCTION ' 1-1
1.1 PURPOSE .. 1-1
1.2 GENERAL SITE ACTIVITY DESCRIPTION . 1-1
1.3 PREVIOUS POLLUTION PREVENTION ACTIVITIES . 1-2
1.4 APPROACH TO THE CURRENT PPOA AT THE NORFOLK NAS 1-3
2 BACKGROUND ." 2-1
2.1 COOLING TOWER PROCESS DESCRIPTION 2-1
2.2 COOLING TOWER WATER TREATMENT 2-4
2.2.1 Sources of Contamination and Resulting Conditions : 2-4
2.2.2 Traditional Methods of Control 2-7
3 SITE ACTIVITY DESCRIPTION 3-1
3.1 GENERAL PROCESS DESCRIPTION 3-1
3.1.1 Cooling Tower Discharge Practices 3-1
3.1.2 Cooling Tower Maintenance Activities 3-3
3.2 CHEMICAL ADDITION PROGRAM 3-3
3.2.1 General Procedure for Chemical Procurement 3-4
3.2.2 Chemical Descriptions and Usage Data , 3-4
3.3 COOLING TOWER DESCRIPTIONS 3-5
3.3.1 BuildingSP367 '....' 3-5
3.3.2 Buildings SP254 and SP256 : 3-5
3.3.3 Building V53 .' 3-5
. . 3.3.4 Buildings SP29 andU16 3-7
3.3.5 Buildings SP45 and SP91 3-7
4 OPPORTUNITY ASSESSMENT 4-1
4.1 SURVEY AND DESCRIPTION OF AVAILABLE OPTIONS 4-1
4.1.1 Non-treatment Alternatives '. .4-1
4.1.2 Chemical Treatment Alternatives 4-7
4.1.3 Non-Chemical Treatment Alternatives , 4-11
4.1.4 Summary of Options 4-20
4.2 ANALYSIS OF FEASIBLE ALTERNATIVES 4-20
4.2.1 Base Conditions 4-22
4.2.2 Summary of Analytical Results 4-22
4.2.3 Conventional Chemical Treatment 4-25
4.2.4 DIAS-Aid Tower Treatment XP-300 4-27
4.2,5 KDF Process - - 4-29
4.2.6 Magnetic Applications Integrated with Solids and Biofouling Control 4-31
4.3 RECOMMENDATIONS FOR FURTHER RESEARCH .' 4-33
-------
CONTENTS (continued)
5 REFERENCES . 5-1
6 BIBLIOGRAPHY 6-1
APPENDIX A PPOA WORKSHEETS .... A-l
APPENDDCB NPDES DISCHARGE LIMITS .. B-l
APPENDIX C MONITORING DATA C-l
APPENDIXD MATERIAL SAFETY DATA SHEETS '..'. D-l
APPENDIX E HAMPTON ROADS SANITATION DISTRICT COOLING TOWER WASTE DISCHARGE
POLICY, INDUSTRIAL WASTEWATER POLLUTANT LIMITATIONS, AND DISCHARGE
REQUIREMENTS E-l
APPENDIXF MSDS FORDIAS-AJD TOWER TREATMENT XP-300 F-l
VI
-------
FIGURES
Number §£§
1 Pollution Prevention Program Overview - • 1-2
2 Typical Three-Loop Air Conditioning Refrigeration System 2-1
3 Schematic of Typical Cooling Tower 2-2
4 Schematic of Typical Forced-Draft Cooling Tower 2-3
5 Schematic of Typical Induced-Draft Cooling Tower, Counterflow Method 2-3
6 Schematic of Typical Induced-Draft Cooling Tower, Cross Flow Method 2-4
7 Typical System Layout for the KDF Water Treatment System 4-13
TABLES
Number ase
1 Master Equipment List, Cooling Towers at Norfolk Naval Air Station 3-2
2 Treatment Chemicals Currently Used at Norfolk Naval Air Station Cooling Towers 3-6
3 Current Annual Chemical Purchases and Costs 3-7
4 General Alternatives for Cooling Tower Water Treatment '. 4-2
5 Bleed and Makeup Water Requirements and Associated Monthly Costs at Different Cycles of
Concentration • • 4-7
6 Summary of Treatment Options: Advantages and Disadvantages 4-21
7 Basic Assumptions for Cost Analysis • • • -. 4-23
8 Annual Cost Summary 4-24
9 Conventional Chemical Treatment Annual Costs 4-26
10 DIAS-Aid Tower Treatment XP-300 Annual Costs 4-28
11 KDF Treatment Annual Costs : , 4-30
12 Magnetic Treatment Annual Costs • • • 4-32
VII
-------
ABBREVIATIONS
AMP
ASHRAE
BTU
Cd
CGC
COMNAVBASE
Cu
DBNPA
DOD
DOE
EDTA
Eh
EPA
FMD
gal
GPH
GPM
HEDP
KDF
Mg
mg/L
Mn
MSDS
NADEP
NAS
Ni
NPDES
NRMRL
ppm
PPOA
Pt
PWC
qt
qv
RREL
SERDP
SIMA
IDS
TIPPP
UV
voc
WET
WREAFS
Zn
Amino-Tri(methylenephosphonic) Acid
American Society of Heating, Refrigerating, and Air-Conditioning Engineers
British Thermal Unit
Cadmium
Coast Guard Cutter
Commander Naval Base (Norfolk)
Copper
Dibromonitrilopropionamide
Department of Defense
Department of Energy
Ethylene Diamine Tetra Acetic Acid
Electrical Potential
Environmental Protection Agency
Facility Maintenance Department
Gallon
Gallons Per Hour
Gallons Per Minute
1 -Hydroxyethylidene-1,1 -Diphosphonic Acid
Kinetic Degradation Flux
Magnesium
Milligrams Per Liter
Manganese
Material Safety Data Sheet
Naval Aviation Depot
Naval Air Station
Nickel
National Pollutant Discharge Elimination System
National Risk Management Research Laboratory
Parts Per Million
Pollution Prevention Opportunity Assessment
Pint
Public Works Command
Quart
Quaternary Ammonium Compound
Risk Reduction Engineering Laboratory
Strategic Environmental Research and Development Program
Shore Intermediate Maintenance Activity
Total Dissolved Solids
Tidewater Interagency Pollution Prevention Program
Ultraviolet
Volatile Organic Compound
Water Equipment Technologies
Waste Reduction Evaluation at Federal Sites (program)
Zinc
VIII
-------
ACKNOWLEDGEMENTS
The authors wish to acknowledge the help and cooperation provided by Sean Heaney and Buddy Clark of the
U.S. Naval Base Norfolk. Other U.S. Navy employees and officials at the facility were also very helpful and
cooperative. In addition, information provided to us by vendors of equipment and services, as well as the useful project
guidance and review comments of the EPA Project Officer, James Bridges, and the EPA Task Work Assignment
Manager, Kenneth Stone, are appreciated.
This report was prepared for the EPA Pollution Prevention Research Branch by Dan Bowman, Jan DeWaters,
Jan Smith, and Scott Snow of TRC Environmental Corporation, under Contract No. 68-D2-0181.
-------
SECTION 1
INTRODUCTION
1.1 PURPOSE
The purpose of this project was to conduct a Pollution Prevention Opportunity Assessment
(PPOA) of the United States Naval Air Station (NAS) at the Norfolk Naval Base in Norfolk, Virginia.
The assessment was conducted under the Waste Reduction Evaluations at Federal Sites (WREAFS)
Program, which is administered by the Pollution Prevention Research Branch in the National Risk
Management Research Laboratory (NRMRL) (formerly Risk Reduction Engineering Laboratory [RREL])
of the EPA. The study was conducted in accordance with the EPA manual, Facility Pollution
Prevention Guide (EPA/600/R-92/088), which provides a methodology for assessing operations to
identify, evaluate, and implement pollution prevention alternatives.
Pollution prevention in environmental management requires the development of a comprehen-
sive program which continually seeks opportunities to implement cost-effective strategies to reduce
waste generation. PPOAs provide detailed assessments of waste streams, options for reducing
waste generation or preventing pollution, and analyses of alternative operating practices which
generate less waste. Appendix A contains PPOA worksheets for the NAS and includes information
obtained during conversations with base personnel and a three-day site visit. Figure 1 identifies the
key elements of a pollution prevention program showing the interrelationship of the PPOA to the
program. The elements of the pollution prevention program are discussed in detail in the Facility
Pollution Prevention Guide.
The approach for conducting a PPOA at the Norfolk NAS is described in this section, along
with background information about the site. Section 2 provides background information related to
cooting tower operations and water treatment processes. Section 3 describes the current cooling
tower activities and operations that were observed during the NAS site visit. Possible alternative
practices for minimizing these wastes are discussed in Section 4. Recommendations on potential
follow-up activities are also included in Section 4. Appendices include PPOA worksheets
{Appendix A), National Pollutant Discharge Elimination System (NPDES) discharge limits
(Appendix B), discharge data (Appendix C), material safety data sheets (MSDS) (Appendix D), the
Hampton Roads Sanitation District Cooling Tower Waste Discharge Policy with Industrial
Wastewater Pollutant Limitations and Discharge Requirements (Appendix E), and the MSDS for
DIAS-Aid Tower Treatment XP-300 (Appendix F).
1.2 GENERAL SITE ACTIVITY DESCRIPTION
Commander,. Naval Base (COMNAVBASE) Norfolk is the world's largest naval base, providing
and coordinating quality logistic support functions for over 100 ships and 50 aircraft squadrons.
Naval Base Norfolk is also the regional coordinator for the Hampton Roads area, which encompasses
all Naval activities within a 50-mile radius. The Navy employs approximately 109,000 active duty
personnel and about 40,000 civilians in Hampton Roads.
The Naval Base complex is approximately 5,200 acres and is heavily industrialized. Over 55
percent of the base land holdings have been developed for current operations, with an additional 25
percent of the land allocated for aircraft runways. The base is comprised of nine subordinate
commands functioning as a consortium of interdependent activities providing core mission and
support services to the largest submarine forces in the world. Core mission facilities include 13,000
feet of runways, 14 piers and 7 miles of ship berthing space. The Naval Base houses the Navy's
largest Supply Center, a Naval Aviation Depot, and a major Military Airlift Command terminal. In
addition, the Naval Base contains the Navy's largest Personnel Support Activity network and the
1-1
-------
Establish the Pollution Prevention Program
Executive Level Decision
Policy Statement
Consensus Building
L_
Organize Program
Name Task Force
State Goals
Complete Preliminary Assessment
Collect Data
Review Sites
Establish Priorities
Write Program Plan
Consider External Groups
Define Objectives
Identify Potential Obstacles
Develop Schedule
Complete Detailed Assessment
Name Assessment Team(s)
Review Data and Site(s)
Organize and Document Information
Define Pollution Prevention Options
Propose Options
Screen Options
t-
Complete Feasibility Analyses
Technical
Environmental
Economic
Write Assessment Report
Implement the Plan
Select Projects
Obtain Funding
Install
Measure Progress
Acquire Data
Analyze Results
Maintain Pollution Prevention Program
Figure 1. Pollution Prevention Program Overview
largest Navy Family Service Center.
Eighty-five Navy Exchange retail outlets
at 55 locations generate annual revenues
of $80 million. The installation contains
2,100 permanent buildings valued at
$2.9 billion, 37 Bachelor Enlisted and 9
Bachelor Officer Quarters, 3,300 family
housing units, and 160 miles of paved
roads.
The NAS functions as a
subordinate command to the Naval Elase,
and is comprised of 598 buildings on
1,266 acres. The NAS employs 10,659
military and 7,685 civilian personnel,
who perform operational support
activities for aircraft and squadrons on
base.
1.3 PREVIOUS POLLUTION
PREVENTION ACTIVITIES
Under the Chesapeake Bay
Agreement, Naval Base Norfolk is a
member of the Tidewater Interagency
Pollution Prevention Program (TIPPP),
The TIPPP is to identify pollution
prevention opportunities, as well as
develop and implement measures to
eliminate pollution at the source. Under
the auspices of TIPPP, a Hazardous
Waste Minimization Study was
completed in 1992 which identified
several pollution prevention opportunities
at the Naval Aviation Depot (NADEP).
After this initial report, the Navy
conducted a pollution prevention
opportunity assessment for the remaining
activities at Naval Base Norfolk, which
included the examination and assessment
of activities at approximately 140 shops
at the base.
Previously completed pollution
prevention studies noted several
hazardous waste management activities
with opportunities for waste reduction
and minimization. Implementation of
plans generated from these studies have
resulted in a decrease in the amount of
hazardous waste generated yearly at
Naval Base Norfolk, as well as significant
1-2
-------
±!±LVi"?.!L!" —^d^SOrha^resuf' ^^^ '" 8dditi°n' ^ establishment of a
1992 the baS8' 8S We" 8S 8n estimated savin9S of $3.4 million during fiscal
Pollution prevention efforts undertaken at Naval Base Norfolk include the initiation of a
"•» - minimization program which focuses on training, education, and single point
» -ssuance. This program was implemented at the Naval Air Supply Station Supply
upply Center, Norfolk Paint Mart, and Reutilization Store. As a result
d.sposal decreased from 408,000 gallons in fiscal year 1990 to 253,000 gallons in
have asu '" ** 8reaS °f electroP'«ing. painting, and deputing
n? ,™ Deduced the quantity of hazardous wastes generated at the Naval Base. Through the use
e ectZa± !±S? T'T' ** quantlty 8"d tOXidty Of -astewaters generated during
wh?rh T ^, P , 8 been redUCed< Furthei™re, the quantity of heavy metal sludges
±±?PICal^COntain Chr°miUm' cadmium- *«™- and nickei, has also been reduced. The
conversion of the pa.ntmg facilities at the base from wet to dry booths is expected to increase the
a^!n0lPaif? tf WWCh Wi" reSUlt in 8 reduCti°n °f the ^antitV ™« toxicity .o f pS ^t wasis!
and w,n lower volatile organ.c compound (VOC) emissions. During departing operations efforts
have been .mp.emented to minimize sand blast grit generation in the paint shops
washers
*??* 1° ***** S0^em U3a9e' aqueous parts washers were installed at the Shore
Maintenance Acfvity (SIMA) and aboard the U.S.S. Theodore Roosevelt at the Naval
T h'9h-pressure water and water-based cleaners, rather than solvents, to
eSt'mated $24'°°° in annua' °peratin9 costs for Phasing solven s
W'th the imP|emen™ion of the aqueous parts
1.4 APPROACH TO THE CURRENT PPOA AT THE NORFOLK NAS
NAO
visit
ViSit/ C°°Hn9 t0wer water treatment methodologies and practices at the
'" tefmS °f the ^es and amounts of waste produced. The Jte
.0? the N0rf°lk NAS Staff Wh° Showed a stron9 interes '"
, ISIt' °Peratin9 personnel were interviewed to gain their
oe sonnenr0vw2em ? PraCt'CeS WhiCh C°UW 'ead t0 reduced waste generation. The operating
personnel provided important input into the characterization of potential alternatives e*nre«inn an
understanding of the importance of minimizing waste whi.e meSSSlon^^
Cunwitly evaluati"9 techniques and technologies to reduce wastes
°peratlons within the Norfo'k NAS. Approximately 28 open- system
TnnCUrrentJy Operated at ™ Buildings within the Norfolk NAS. These
operae on a s,nnh tO,300 tons' and are a« associated with comfort cooling systems which
operate on a seasonal basis (approximately 6 months per year).
Open-svstem ^circulating cooling towers consist mainly of water
^ t0 the enVironment a10"9 with
-------
alternatives, and assesses these treatment options in terms of their technical and economic
feasibility as well as their overall effect on the quantities and the constituents of the waste produced
by each affected process. Finally, selected treatment options are recommended for further
evaluation.
1-4
-------
SECTION 2
BACKGROUND
2.1 COOLING TOWER PROCESS DESCRIPTION
A cooling tower is an enclosed device designed for the evaporative cooling of water by direct
contact with air. Cooling towers are used in conjunction with air conditioning and industrial process
equipment and act as the heat sink for these systems by providing a continuous source of cool
water for process operations. Open-system recirculating cooling towers are typically chosen for
operation with air conditioning and refrigeration equipment because they are relatively inexpensive
and minimize heat rejection costs while still conserving water. All of the cooling towers at the
Norfolk NAS identified in this PPOA are of the recirculating, open-system type.
Evaporation accepts
heat from condenser
water
Condenser water
refects heat to
evaporation.
Condenser water
accepts heat from
refrigerant
Refrigerant rejects
heat to condenser
water.
A typical three-loop air
conditioning refrigeration system is
shown in Figure 2. Air conditioning
can be thought of as the addition of
refrigeration to the heating and
ventilation of a building in order to
provide cooling and dehumidification
(Gumey and Cotter, 1966). Heat and
moisture from the conditioned space
are extracted at the air coil where the
refrigerant, which is chilled water in
this case, conveys this heat away
from the conditioned area. The heat
is dissipated under low grade
conditions (i.e., with a relatively small
change in temperature), as the weiter
is re-cooled for reuse by means of the
water cooling tower.
Cooling towers operate by
passing warm water through cool air,
which transfers heat from the water
to the air. The warm air is
discharged, and the cooled water is
then used for air conditioning or other
equipment cooling. Water cooling
occurs in the tower through both
evaporation and the transfer of heat to the air flowing through the water. To maximize heat transfer
and subsequent water cooling, cooling towers are designed to optimize air/water contact. Figure 3
illustrates a typical cooling tower. Water is distributed as evenly as possible across the top of the
tower and is allowed to fall through the tower. Simultaneously, air is drawn into the tower and is
circulated upwards through the water column, cooling the water as it falls through the tower.
I
Pi,
Fvaporator
r
Refrigerant accepts '
heat from chilled I
water. •
Chilled water rejects \
heat to refrigerant I
Chilled water accepts •
heat from room air. i
Room air rejects heat \
Figure 2. Typical Three-Loop Air Conditioning Refrigeration
System
2-1
-------
Multi-blade
Distribution
Area
Splash Bar
Grid and
Supports
Air Flow
Louvers
/— End Wall
/ Casing
-Air Flow
Drift Eliminators
\_
Longitudinal
Partition
Figure 3. Schematic of Typical Cooling Tower
Cooling towers can be classified as natural or mechanical draft systems. Natural draft cooling
towers are designed to take advantage of the temperature differences between the hot air inside the
tower and the cooler air outside. The cooler air entering the bottom of the tower pushes the warmer
air out of the top without the assistance of blowers or fans. Mechanical draft towers, which use
fans or blowers to force air through the tower, may be of either the forced- or induced-draft type
and are generally used with air conditioning units. Typical forced- and induced-draft cooling towers
are shown in Figures 4, 5, and 6. Forced-draft cooling towers have a fan at the air intake, which
forces air into and through the tower; in induced-draft towers, both counter flow (5) and cross flow
(6) have a fan at the air outlet which draws air through the tower.
2-2
-------
Air Out
Packing
Fan
AH-In
Water Out
Figure 4. Schematic of Typical Forced-Draft Cooling Tower
Water In
AlrOut >X~Fan
JL«L^r
»*
V J
^ V 7*™ V ^
Water Out
Figure 5. Schematic of Typical Induced-Draft Cooling Tower,
Counterflow Method
2-3
-------
Air In
Water Out
Air Out
'acting
Air In
Figure 6. Schematic of Typical Induced-Draft Cooling
Tower, Cross Flow Method
Open cooling systems utilizing recirculation have the potential to minimize water consumption
because a much of the process water is recirculated through the tower for reuse. A onctthrZh
system m contrast, uses a continuous source of cool water which is pumped through the water
jacket of a heat exchanger where it absorbs heat before being discharged. * a -^SS^SL^
a continuous source of makeup water is required to replenish the water which is evaporated I f the
tower dunng the heat transfer process. Additional makeup water is required as wateNs lost from
the tower due to tower bleed or blowdown. which is the discharge oTsystem water * controT
concentration of suspended solids and impurities, as described below. . «». corraoi
2.Z COOLING TOWER WATER TREATMENT
2-z-'t Sources of Contamination and Resulting Conditions
All natural waters contain various amounts of impurities such as dissolved solids
abofSroSPtHdedJraT GaS6S SUCh 8S Carb°n di°Xide' °^en' 8nd surfuTdioS e
absorbed from the atmosphere and from organic decay to form dilute acids. Dissolved solids
£±S r6?,^1 SdUm 8nd ma9neslum' as we» « iron, silica, and carbonates are
absorbed from the earth and are the basis of scale-forming water hardness. Suspended solids,
2-4
and
-------
mn , ^rbldltV' C°nSiSt °f Silt' Clay' and a variet* of Or9anic constituents, including
microorgamsms oils, fats, greases, and sewage. In addition, all waters have the potential to
developmg algal and biofilm growths under favorable conditions including sunlight, warm
temperatures, and abundant water with a high concentration of nutrients.
As water evaporates during the cooling process, impurities and minerals which enter the
tower ,n the makeup water are left behind and accumulate in the cooling tower and process
rormTnT^ ™Vc*urlati°n of '"purities leads to a variety of problems including scale formation
tTn±??' ."l"9 °f SUrf8CeS dUe t0 bi°l09lcal 9rowth' These conditions fn turn cause heai
transfer losses, metal detenoration, and blockage which decrease the tower efficiency.
2.2.1.1 Scale- .
«,
cau
°f ?* o°Sf SfriOUS problems which can develop in untreated cooling tower water is that
scale. Scale formation occurs when the solids in the cooling tower water reach thi
iZ« 2L K- i7 TH Predpitate out onto wet surfaces. When the precipitates fall onto mutinous
films, they bind to the metal surface and begin to form scale. Scale is commonly caused by the
precipitation and binding of magnesium, calcium, sulfate, phosphate, hydroxides, and silicate
co mp o u no s * • '
S?Kn? JS I?8?1 10 Wat6r characteristics such as dissolved salt concentrations, total
nHn, L !' !fS/ 8lkalinitV' 8nd temPerature- Water hardness is caused by the presence
of dissolved calcium and magnesium salts which remain soluble under many environmental
cond,t,ons but precipitate out of solution as scale when exposed to elevated temperatures or exist in
As a resuit' hard water in a coolfn9 system requires extra attention and
t« * Prele "Ce °f SC3le deposits on heat transfer surfaces results in a reduced capacity for heat
transfer from the water to the air. This in turn results in higher operating temperatures and high r
power consumption as the air conditioning unit unsuccessful tries to coo. the wate? Tne decrease
LtemT9 6. t-6"0" Hnd th6 inCreaSed Strai° °" the Coolin9 tower unit maV eventually tead to
system degradation and costly system shutdown and repair.
2.2.1.2 Corrosion-
C°7sion occ^s as metal Parts deteriorate and revert to their original (ore) state, resulting in
" t 8 int^rity> TW° typet °f C0rrosion' 9eneral and Pj«in9' common y occu in a
the '^ Genera' C°"°Sl°n °CCWS Whe" the Corrosion attack is uniform and
aSi?11" area ?f the metal> Pltti"9 °CCUrS ln Sma" locaiized areas' for
unde, scale deposits. As a result, rapid penetration of the metal and subsequent failure occurs.
nPntr,PnrT,SiK?,Pr^e,SSeS 9e"era"y Proceed raPid|y ""der acidic conditions, and more slowly under
also td to ?or n a!ka"nftcondltions- The P'es*nce of high concentrations of dissolved so.ids ca
corr°s'on- O
factors contributing to corrosion include high temperature, high oxygen
^ °f 'iqUid (W3ter> °n the meta' SUrfaCeS' 3nd 9a'Vani^ action of ?wo
2.2.1.3 Saturation and Stability Index-
to a I'.mpnt SCaHn9 tendencies are r^ated characteristics, both of which depend
pnt ,
nn f .e concentration of dissolved solids, temperature, alkalinity, and PH The
tendency of water to deposit scale when it is alkaline or to attack metals corrosrvely when rt is
2-5
-------
acidic depends on the balance of various constituents in the water. Water described as "in
balance," explained below, exhibits neither corrosive nor scale-forming characteristics.
The Langelier Saturation Index and the Ryznar Stability Index are commonly used to predict
scale-forming tendencies or corrosive properties of a cooling water. The Saturation Index represents
the difference between the actual measured pH and the calculated pH at saturation with calcium
carbonate. A positive number indicates that calcium carbonate scale will form, while a negative
number indicates that the water has corrosive tendencies. A stability index of 0 indicates a water
which is in balance exhibiting neither corrosive nor scale-forming tendencies. Ryznar's Stability
Index was developed to provide a closer correlation between the calculated prediction and the
quantitative results in the field. With an optimum value of 6, scale formation can be anticipated at
values less than 6, and corrosion at values greater than 6.
2.2.1.4 Fouling-
Fouling problems arise from the deposit of solids and the growth of microorganisms on
cooling tower surfaces. Fouling can occur in a cooling tower in a manner similar to scaling. The air
passing through the cooling tower contains small amounts of contaminants including silt, dust,
organic debris, and other entrained particulates. These particulates can be washed from the air into
the cooling water and become suspended or dissolved solids. The subsequent precipitation of these
solids onto heat transfer surfaces can leave a silt-like deposit similar to scaling and reduce the
efficiency of the cooling unit.
In addition, these silt-like deposits may provide nutrients for various microorganisms including
algae and bacteria. Common biological growths found in open recirculating water systems include
algae, bacteria, molds, and fungi. The uncontrolled growth of these microorganisms can lead to
reduced water flow, plugged pipes, a loss of heat transfer capability, severe corrosion in areas
surrounding the growths and deposits, and ultimately, equipment failure.
Algae are the most common microbiological growths found in open recirculating water
systems and account for the majority of the problems encountered. Green algae is the type most
commonly found in the fresh-water environment. To survive, algae require air, water and sunlight.
When they are exposed to light, algae produce oxygen and consume carbon dioxide. Most algae
prefer moderate temperatures <60°F to 100°F); however, they can withstand temperatures from
below zero to boiling. In addition, algae require elements such as calcium, phosphorus, magnesium,
and silicon. As a result, the most abundant algal growths are found in warm, sunny areas with
large amounts of hard water.
Bacteria present a minor problem when compared to algae. The most important types of
bacteria are those which react with sulfur and iron. The presence of these types of bacteria may be
noted by increased turbidity in the water, as well as a sulfur or "rotten egg" odor in the water
Abundant numbers of bacteria may actually turn the water red, and leave a reddish sludge deposit in
water pipes, nozzles, pumps, and other equipment.
Fungi and molds are the most biologically complex of the three types of microbiological
organisms found in open recirculating water systems. Fungi and molds have a plant body with
many fine, elongated cells that form a fibrous network. They also have a root structure which
attaches them to the cooling tower and provides a base for nutrient gathering. Most commonly,
fungi and molds tend to grow on wooden surfaces; but they can also grow on cement, metal or
fiberglass. The presence of these microorganisms can result in deterioration of the surfaces to
which they are attached.
2-6
-------
2.2.2 Traditional Methods of Control
In the past, various water treatment philosophies and their associated devices have avoided
the problems related to high concentrations of impurities by increasing the bleed or blowdown of
process water from the tower. By increasing the amount of water released from the system, these
treatments are increasing the makeup water requirements and operating the system at low
concentrations of suspended solids. The amount of blowdown necessary to maintain a particular
maximum mineral concentration is related to the operating cycles of concentration, which refers to
the number of times the minerals are concentrated in the system. The cycles of concentration are
defined as the ratio of chloride concentration in the cooling system to the concentration of chloride
in the makeup water. Conductivity or any dissolved compound could be used in calculating cycles
of concentration, but chloride is typically chosen because it is soluble and does not form precipitates
as do calcium, magnesium, carbonate, phosphate, silicate, and occasionally other ions (Meitz,
1990).
Systems which operate at high cycles of concentration minimize the bleed or blowdown rates
and are capable of substantial reductions in makeup water requirements and associated water and
sewer costs. However, the risk of severe scale or corrosion problems increases dramatically with
higher cycles of concentration. Provisions are necessary to handle high solids and higher
concentrations of corrosive ions such as chloride and sulfate, as well as ions that precipitate,
particularly those associated with hardness and alkalinity. This is traditionally accomplished by
standard water treatment techniques which include the addition of treatment chemicals to the
circulating water for scale inhibition, corrosion control, and control of microbial growth.
2.2.2.1 Scale Control-
The traditional practice for scale control involves the discharge of cooling tower blowdown to
the sewer, thereby controlling the concentration of dissolved minerals to levels below the saturation
point. However, as the cost of makeup water has increased, this practice has become less
attractive. Scale deposits can also be minimized by maintaining a low system operating pH since
the solubility of most mineral salts increases under acidic conditions. However, the resulting acidity
of the process water will lead to corrosive conditions in the tower. Internal treatment for scale
deposits usually involves the addition of dispersion agents or polymeric materials and scale inhibitors
under slightly alkaline conditions. If the scale-forming ions can be tied up with complexing agents,
their propensity to form precipitates that lead to scaling is reduced.
Among the most widely used dispersants for cooling water treatment are a number of
polymers and copolymers, such as polyacrylic acid and its salts, acrylamide-acrylic acid copolymers,
polymaleic acid, sulfonated polymers, and many others. In general, dispersants consist of low
molecular weight polymers (below about 20,000), while those with molecular weights approaching
10° and above are used as flocculents. Other commonly used dispersants consist of chemically
modified natural products such as tannins, lignosulfonates, and carboxymethyl cellulose. In
addition, newly developed polymers are being produced which provide effective dispersion at much
lower concentrations and can be tailored for dispersion of specific foulants.
Scale inhibitors function either by altering the crystalline structure of the scale-forming salts,
or by coating the particles with a film which prevents coagulation. Polymers such as
polyphosphates, phosphonates, and phosphate esters act as inhibitors for inorganic crystalline
scales such as calcium carbonate and calcium sulfate, and they stabilize iron and manganese.
Polyphosphates retard or delay the rate of precipitation by absorbing onto crystal faces thereby
arresting the growth of the crystal. Stabilization depends on the time interval necessary, the
operating temperature, and the presence of sufficient quantities to effectively prevent precipitation.
2-7
-------
Polyphosphates encourage biological growth and also readily revert to orthophosphates which do
not prov,de effective protection. Organic additives such as lignins, tannins, and ethylene diamine
tetra acetic ac.d (EDTA) are often used in combination with polyphosphate treatment. The organic*
function by sequestration, reacting with minerals to form insoluble complexes that do not precipitate
and are removed with system blowdown.
Although adding chemical dispersants and scale inhibitors will extend the solubility of many
elements dissolved or suspended in the water, eventually a saturation point will be reached and
precipitation will occur. In addition to chemical inhibitors, an effective chemical treatment program
for scale inhibition includes a periodic blowdown of the system to limit the concentrations of
dissolved solids.
2.2.2.2 Corrosion Control-
Chromates have historically been the most widely used additive for corrosion control.
Typically, an acid feed was administered to maintain the system pH between 6 and 7, thereby
reducing scale problems due to the increased solubility of dissolved minerals at a low pH.
Chromates were used under these acidic conditions because they are good oxidizing agents in acid
and react to maintain a protective film of oxide at the metal surface. As much as 2,000 parts per
million (ppm) chromate were typically used in the 1960s (ASHRAE, 1973). The toxic characteristics
of Chromates provided further protection against microbial growth. Due to environmental concerns,
Chromates were banned from use in comfort cooling systems in 1990 (EPA, 1990).
Chromates largely have been replaced with non-chromate treatment programs using
Polyphosphates, orthophosphates, zinc compounds, nitrites, phosphate esters, phosphonates,
azoles, molybdates, and silicates. When Chromates are omitted, corrosion inhibitors are generally
used at higher concentrations to be effective.
Treating cooling water with chemicals to make it less aggressive (e.g., by dispersion of
suspended solids), offers some degree of corrosion protection, although effective control is typically
achieved by using corrosion inhibitors to form a protective film. Inhibitors may be inorganic or
organic. Inorganic inhibitors, in turn, may be further classified according to those that require
oxygen, such as sodium phosphates, silicates, and borates, and those that function with or without
oxygen, such as chromate and nitrate. Inhibitors may also be classified in terms of their
mechanism, that is whether they function by influencing the anodic or cathodic side of the
electrochemical cell, although this depends largely on conditions of pH, temperature, and oxygen
content. Inorganic inhibitors usually affect the anodic process. In general, Chromates, nitrites,
silicates, phosphates, ferrocyanides, molybdates, and borates are considered to be anodic inhibitors
Anodic inhibitors function either by forming a film on the metal surface or by chemisorption on metal
surfaces. The dosage depends on the temperature, salt content, nature and location of dissimilar
metals, and the ratio of metal surface area to volume of solution. Silicates require close pH
monitoring, which should be maintained between 6.5 and 7.5. Although they are successful in soft
water areas, silicates are not recommended for alkaline waters. High silicate concentrations lead to
precipitation of calcium silicates. Nitrites require relatively high concentrations and close pH control
(usually 7.0 to 9.0). Nitrites decompose and the result is serious corrosion at a pH of less than 6.5.
The nitrites are also subject to conversion to nitrates by-nitrobacteria. Although they have a long
history of use as single-component inhibitors, nitrites and silicates are not acceptable for cooling
tower applications.
Polyphosphates are widely used corrosion inhibitors that have a long history of use.
Polyphosphates and phosphonates form a protective iron-orthophosphate film which also helps to
prevent carbonate deposition on metal surfaces. However, polyphosphate reverts to orthophosphate
2-8
-------
with possible precipitation as complex calcium phosphates, depending on calcium and
orthophosphate concentration, pH, temperature, and total solids concentration. Phosphates tie up
iron ions and prevent the formation of rust, although the phosphates used for corrosion inhibition
lead to the formation of calcium phosphate and resulting scale deposits.
Inhibitors that react with the cathodically generated hydroxide to form an insoluble compound
such as Mg". Cu**, Zn", Cd2*, Mn'*, and Ni'% are considered to be cathodic. Cathodic inhibitors
function by forming insoluble hydroxides at cathodic areas, causing cathodic polarization None are
practical corrosion inhibitors when used alone.
Formulations for corrosion control that contain mixtures of inhibitors generally provide greater
protection than individual components. Corrosion control has historically been effective through the
widespread use of combinations of polyphosphates, nitrites, chromates, zinc, and silicates.
Although zinc is still widely used in treatment formulations, chromate has been omitted.
Furthermore, non-heavy metal treatment programs in which zinc has been omitted are receivinci
increasing attention.
Widely used non-chromate mixtures include zinc with polyphosphate, organic phosphonate,
molybdate, or lignin derivatives. Non-heavy metal formulations in which zinc has been omitted
include combinations of polyphosphates, amino-tri(methylenephosphonic acid) (AMP) and 1-
hydroxyethylidene-1,1-diphosphonic acid (HEDP); mixtures of polyphosphates with phosphonale or
silicate; and combinations of phosphates AMP and HEDP with polymers. Most formulations include
a polymenc dispersant such as polyacrylate, which maintains sediment, scale, corrosion products
and organic particles in suspension, thereby minimizing the risk of pitting, corrosion under a deposit
and other forms of localized corrosion. Many non-chromate mixtures operate within a relatively
narrow pH range of 6.5 to 7.5, to effectively control corrosion or to prevent the precipitation of
zinc. Formulations which do not contain zinc function cathodically and are more effective with
higher pH values, typically from pH 7.3 to pH 9.5 (Hey and Hollingshad, 1987).
Many organic compounds have been used as corrosion inhibitors. Organic inhibitors function
by bonding with the metal surface through forces including electrostatic adsorption, chemisorption
and delocahzed electron adsorption. Organic corrosion inhibitors used in cooling tower water
treatment applications include amines, amides, pyridines, carboxylic acids, esters, mercaptans and
formulations of alkylthiophosphate, organic phosphate esters, and zinc salts. Organic additives and
surface active materials in conjunction with polyphosphates, zincs, or chromates improve the
corrosion inhibition efficiency of the inorganic inhibitor. Organic additives interfere with the
precipitation of inorganic salts and aid in dispersion of suspended solids.
2.2.2.3 Fouling Control-
Biofouling results from the growth of microorganisms which plug water distribution holes and
interfere with droplet formation in the tower thereby reducing heat transfer efficiency. Biological
growths histoncally have been controlled by chemical or mechanical means. Chemical controls
involve the addition of oxidizing or nonoxidizing biocides and algicides. Among the oxidizing types
are chlorine gas, chlorine dioxide and chlorine donors such as calcium hypochlorite. Although
chlonne is inexpensive and widely used, its biocidal properties are pH-dependent. The pH of the
water needs to be slightly acidic because the toxicity of chlorine depends to a large extent on the
formation of hypochlorous acid. In a pH range of about 4 to 6, chlorine gas hydrolyzes to form
hypochlorous acid and small amounts of hydrochloric acid. Chlorine is a relatively poor biocide
above a pH of about 7.5. This limits its application to cooling tower water treatment because many
corrosion inhibitors operate in the alkaline range. Moreover, chlorine is corrosive and forms toxic
organochlorme compounds. Discharge regulations for chlorine are more stringent than for other
2-9
-------
biocides because of concerns over its role in the formation of trihalomethanes. Additionally
chlorination has been shown to reduce the effectiveness of the two most commonly used organic
phosphates in cooling tower water treatment applications: AMP and HEDP (Tvedt and Wilson,
1985).
Nonoxidizing biocides include the isothiazolins, dibromonitriloproprionamide (DBNPA)
quaternary ammonium chlorides, carbamates, and organotin compounds. Quaternary ammonium
compounds (qv) are the largest class of nonoxidizing microbiocides used in water systems. These
compounds exhibit surfactant properties which tend to loosen and penetrate existing biofilm
accumulations thereby facilitating more rapid and effective treatment. Isothiazolin-based
microbiocides have been shown to be particularly effective against biofilm organisms (Richardson
1982). DBNPA is relatively effective at low levels, and decomposes into products that are less toxic
than the parent compound. These characteristics make it an attractive additive for discharge
purposes. Organic sulfur-containing compounds represent another class of nonoxidizing
microbiocides. Most commercially formulated products consist of a mixture of several microbiocides
combined with dispersants and surfactants which increase product effectiveness by breaking up
accumulated slimes and algae.
Due to the ability of microorganisms to rapidly grow and multiply, they can easily become
immune to many biocides. As a result, microbiocides are added intermittently in large doses, to
minimize the tendency for microorganisms to become resistant to the chemicals. The likelihood of
N resistant strains is further ensured by using alternating dosages of two or more different chemical
formulations. '
Other traditional methods for controlling the growths of microorganisms include pH
adjustment and the shielding of wet surfaces from sunlight. Microorganisms need a pH of
approximately 6.5 to grow at optimum rates. Therefore, significant changes in the pH levels will
reduce the growth of the microorganisms. However, a low pH will noticeably increase corrosion
rates and should be avoided. An elevated pH will increase the formation of scale deposits.
Therefore, a microorganism control program which increases pH must also increase the bleeding rate
to control the formation of scale deposits. Algae need air, water, and sunlight to survive, and
effectively removing sunlight from wet areas will control the growth of algae. Sheet metal or marine
plywood are usually adequate for this purpose, although inadvertently restricting air circulation
through the cooling tower should be carefully avoided.
2-10
-------
SECTION 3
SITE ACTIVITY DESCRIPTION
3. 1 GENERAL PROCESS DESCRIPTION
Approximately 598 structures are located at the Norfolk NAS. Of these, 18 buildings are
equipped -with air conditioning systems operating in conjunction with evaporative recirculating
cooling towers for a continuous supply of process water. The air conditioning systems provide
comfort cooling during warm spring and summer months, largely between April and October The
NAS cool.ng towers do not operate during the cool season. Table 1 is a master equipment list:
showmg that 28 cooling towers provide process water for the air conditioners which service these
18 bu.ld.ngs As described in Table 1, these cooling towers are located on roofs, are adjacent to an
exterior wall, or are in a courtyard outside of the building. They range in capacity from 5 tons to
JOO tons. One cooling tower ton is equivalent to the removal of 1 5,000 BTU/hour.
Also included in Table 1 is a description of the current treatment status for each NAS cooling
tower As indicated, only 10 of the 28 towers are currently receiving chemical treatments for
control of scale, corrosion, and biofouling. The remaining 18 towers are small units that do not
^Sections* SndsT"' ^"^ ** °PeT**n9 SeaSOn' ^ chemical addition P^ram is discussed
The last column in Table 1 lists the available system water volume in gallons. The volumes
° r'Ve l°Tu°f the altemative treatment costs in Section 4. These system volumes are
values wh,ch have been obtained from Base personnel. System water volumes depend
prirnanly on unit s.ze, but are also influenced by the cooling tower locations and piping systems.
3.1.1 Cooling Tower Discharge Practices
AH cooling towers at the NAS receive makeup water from the City of Norfolk public water
vavwhrhHtth °bserved durin9 the site vi*t was equipped with a discharqe
valve wh,c
th
the tower blowdown into floor drains located in the vicinity of the heat
exchanger and condensed water pump. This equipment was typically situated within the
mechanical room of the particular building being serviced by the unit. The observed flowrates of
trash makeup water and tower discharge varied from unit to unit.
confid hKK,
-------
TABLE 1. MASTER EQUIPMENT LIST - COOLING TOWERS AT NORFOLK NAS
Cooling Towers Receiving Chemical Treatment'
081275
--
—
028197
028198
021087
024341
081218
093171
093172
SP367
SP254"
SP256**
V53
V53
SP29*»
U16'"
SP45
SP91
SP91
East Outside
Roof
Roof
Roof
Roof
West Courtyard
East Side
South Side
Behind Building
Behind Building
75
200
200
150
175
300
300
125
100
40
Cooling Towers Not Receiving Treatment"'
127
600
1,000
1,200
1,400
3,500
2,500
1,250
1,000
400
022189 LP13
080394 LP13
086933 LP13
080385 UP2
080386 LP2
080387 LP3
080388 LP3
022188 LP4
080389 LP4
052754 S33
O86998 S33
O93369 SP238
097454 SP64
021751 T26
085676 T26
085677 T26
050597 U48
083286 V82
Roof East Side
Roof West Side
Roof West Side
Roof West Side
Roof East Side
Roof West Side
Roof East Side
Roof East Side
Roof West Side
Roof
West Side
South End
Outside Building
Roof East Side
Roof West Side
Roof
West Side
Roof
•vX^i?*1? °f t?atn?ent at *« time °f «P°rt preparation. August 1994.
•-Th^rn • ^T^ HaS bfle" instituted « *"• new units since the site visit in
The cootag towers currently not receiving treatment are designed for chemical
-These two new unrts have not yet been issued equipment identffication numbers
25
25
25
25
25
55
^9
20
.
20
?n
£*W
BO
ww
60
7c
•9
45
June 1994.
treatment.
N/A
N/A
kllA
N/A
M / A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
- > fct/A
N/A
N/A
N/A
N/A
N/A
3-2
-------
Appendix C contains monitoring data collected from stormwater outfall no. 077 { currently
112) As shown in the data reports, the concentrations of zinc and chromium in outfall no 077
1 oorJ exfedetd the NPDES Pitted discharge limits on two separate occasions, in the winter of
1 993 and in the spring of 1 994, respectively. After each exceedance, a sample was collected from
the cooling tower drainage at building V53 in an effort to locate the origin of the-zinc and chromium
?,« T98' However' on both occasions the samples collected from the cooling tower at building
V53 did not show a correspondingly high concentration of the contaminant of concern Despite
these inconsistencies, it is believed that the cooling tower at building V53 discharges to NPDES-
permitted stormwater outfall no. 077 (1 1 2) (Sean Heaney, Naval Base Norfolk, personal
communication, 1994.).
3.1. -2 Cooling Tower Maintenance Activities
*K D ^,ain,t.?n anCe 8nd operatlon of tne C00lin9 towers and air conditioning units are performed by
the Public Works Command , under contract to the NAS. PWC personnel do not currently
have a systematic method for managing the NAS cooling towers. As indicated in Table 1 and
described in Sections 3.2 and 3.3, 1 0 of the 28 NAS cooling towers are serviced under a chemical
treatment contract to PWC by one of two water treatment specialists. Each of these ten units is
maintained by a treatment representative, whose primary responsibility includes cooling tower water
testing and treatment. Additional responsibilities of the water treatment contractor vary depending
on the details of the contract, but these may include regular cleaning of the tower to remove
. accumulated sludge and debris.
The remaining towers which are not serviced by a contractor are the responsibility of PWC
mechan,cs. These units receive no chemical treatment during the operating season, aside from the
occasional addition of b,oc.de to control excessive fouling. PWC mechanics operate under a
budding ownership- system whereby certain mechanics have maintenance duties for certain
buildings. Building maintenance includes the servicing of cooling towers and ancillary equipment.
General maintenance activities for the cooling towers not serviced by a water treatment
specialist include an annual overhaul of each unit, which is performed during the winter months
while the unit is not operating. The annual overhaul consists of external cleaning with brushes and
water flushing, and, depending on the general state of the unit, completely disassembling each unit
for interior cleaning. Interior heat exchanger tubes are cleaned by a process known as "reddening, •
in which a rotating brush is inserted into each tube in combination with a water flush. Although this
process is typically performed only once a year, heat exchanger tubes may be cleaned at other times
rfr^n « 'S S£0wm9 signs of scali"9 or fo""ng. Signs of scaling and fouling include a high pressure
drop or small change in temperature across the unit. Cooling towers are normally designed to
operate with a 1 0°F temperature drop across the tower.
Following the annual overhaul, PWC maintenance personnel apply an algicide to each of the
cooling tower units not serviced by a chemical contractor. A one-gallon container of Calgon algicide
is fed by continuous drip to each unit to control biological growth in the system. Some of the
ST.? "!7 °ccasioIn,fllv receive additional biocide during the operating season to control excessive
biological fouling, although application rates and schedules vary.
3.2 CHEMICAL ADDITION PROGRAM
ourrhthn- trf 3tme"t Pr°9fam instituted « the Norfolk NAS involves PWC personnel, who
purchase the chemicals, and a water treatment contractor, whose responsibilities include testing the
as needed- and adjustina control parameters such a
3-3
-------
Of the 28 cool.ng towers in operation at the NAS, a total of 1 0 are currently receiving
chemical treatment. These ten cooling towers, identified in Table 1, are serviced under contract by
n«f H f.tw_° c,°° '"9 tower water treatment specialists who also service other units on base. As
thpf«!p f , T H°-f theSG UnitS afe 6quiPPed With Chemical pumps and meterin9 systems but
they were not included in a chemical treatment contract at the time of the site visit in June 1994
Chemical treatment programs have recently been implemented at these four units. In the future,
PWC intends to hire one water treatment specialist to maintain and service all cooling towers at the
Naval Base Norfolk. The contractor would be required to inspect each tower on a monthly basis and
would chemically treat the towers as needed. Thus, all towers at the NAS will eventually be
included in a chemical addition program.
3.2.1 General Procedure for Chemical Procurement
The procedure for procurement and administration of water treatment chemicals involves a
cooperative effort between the appropriate PWC personnel and the water treatment or chemical
contractor responsible for the unit. Each cooling tower under contract to a water treatment
specialist is inspected periodically to ensure that the tower is operating property and is receiving
adequate chemical treatment. Operating malfunctions are corrected by the contractor. If the
contractor determines that additional chemicals must be purchased, PWC is notified. PWC
personnel order the appropriate materials for delivery to the specific building at the specific zone on
base. PWC orders all cooling tower chemicals in an effort to minimize the purchase of excess
matertals: After the chemicals arrive on site, the contractor returns to administer the treatments.
^ DiA, personnel who were interviewed during the site visit stated that under no circumstances
do PWC maintenance personnel administer chemicals to the NAS cooling towers, regardless of
whether or not the towers are maintained under contract by a water treatment specialist. At the
time of the s.te visit, however, two towers were observed that were not currently under contract by
a water treatment specialist but that were connected to a chemical holding tank and an engaged
metering pump. Based on these observations, the actual chemical administration procedures as
practiced remain somewhat uncertain.
A chemical exchange program exists within each zone on base. Most chemicals are stored in
the mechanical room of the building in which they are used. As more chemicals are needed by a
particular building, PWC will first verify that excess chemicals do not exist in storage at another
bu.ld.ng before ordering a new supply. This procedure avoids excess stockpiling of chemicals.
Although PWC is in charge of ordering alt cooling tower chemicals, no purchase records are
maintained at PWC. Purchase records are maintained in the Base Supply, building X275 MSDS
files are maintained in the Safety Department, building Z1 40.
3.2.2 Chemical Descriptions and Usage Data
The chemicals used for cooling tower water treatment at the NAS are presented in Table 2
along with their primary ingredients, type of control, application rate, and frequency of use
Append* D contains the MSDS for each of the chemicals used. These chemicals are applied by the
two water treatment specialists currently under contract to service the NAS cooling towers
Purchase data for these chemicals were unavailable from PWC. However, typical application rates
tor each chemical, shown in Table 2, have been combined with cost information to estimate annual
usage rates and associated costs. Usage rates are based on a six month operating season and
assume that all towers operate with 4 cycles of concentration at 100 percent capacity for 12 hours
in T w o sAummary of tne annual usase rates and costs for each treatment chemical are presented
in i able 3. As described above, the chemicals applied to each of the NAS cooling towers, which
total approximately 814 gallons, are ultimately discharged to the environment through tower bleed
3-4
-------
The total annual chemical costs for the NAS cooling towers currently receiving chemical treatment
are estimated to be approximately $13,876.
3.3 COOLING TOWER DESCRIPTIONS
Seven of the cooling towers listed in Table 1 were observed during the site visit, including
towers at buildings SP367, V53, SP254, SP256, SP29, and U16. The observed cooling towers are
among the largest units and, although all were equipped with automated valves and chemical
metermg pumps, the four units at buildings SP254, SP256, SP29, and U16 were not yet under
contract for chemical addition. Chemical addition programs have been instituted at each of these
towers since the time of the site visit.
The remaining NAS cooling towers which are not chemically treated consist primarily of small
units, ranging in size from 5 to 60 tons, with most being 25 tons or less. These towers were not
observed during the site visit because they were not being chemically treated. However, the size
and operation of these additional towers will be considered in the overall assessment of cooling
tower activities and treatment options, since they will be included in any treatment program which
encompasses all NAS cooling towers.
3.3.1 Building SP367
The cooling tower at Building SP367 is a 75-ton unit located on the east side of the building
This unit was observed to be continuously bleeding a large amount of water directly into a sump
which, according to base personnel, apparently discharges to the sanitary sewer. The discharge
problem was apparently due to a manual bleed valve which was locked in the open position The
bleed flowrate is unknown; however, the measured total dissolved solids (TDS) in the tower were
approximately 200 ppm. This rate is identical to that of the makeup water from the city of Norfolk
This level of TDS indicates that the tower was not effectively recycling water but was operating
instead as a once-through system. Chemicals used regularly in this tower include an algicide and a
scale and corrosion mhibitor, both are fed by a continuous drip. A dispersant used once or twice
per year dunng startup and shutdown procedures.
3.3.2 Buildings SP254 and SP2SS
the rrinfnf * Buildings SP254 and SP256 are new, 200-ton units located on
the roof of each budding. These units have automated controls in place to measure conductivity
which is an indicator of TDS. The controls automatically open the tower bleed valve when TDS
measures are greater than approximately 600 ppm. Automatic metering pumps are in place for
continuous chemical addition. Although the controls were observed at the time of the site visit
chemicals were not being dispensed to these units. A chemical addition program has been '
implemented at these cooling towers since that time. Chemicals used regularly in these towers
include an algicide and a scale and corrosion inhibitor. Both are fed by an automated drip system,
and a dispersant is used once or twice per year during startup and shutdown.
3.3.3 Building V53
h,,iiH- C°0li?-9 tOW6rS 8t Bui'ding V53 are 15°- and 175-ton units located on the roof of the
building These cooling towers are relatively new and are constructed of a plastic material The
material S^nn'thT!?"9 th6Se UnitS expressed ^^satisfaction over the performance of the new
matenal, indicating that the units are not capable of achieving a sufficient temperature drop in
o? a-"? ™3t th SS£Tm temperature dr°Ps achieved ac««s the units were reportedly in the ranqe
of 8 F, not the 10°F temperature drop desired.
3-5
-------
CA
S
O
o
o
o
o
i
o
g
z
2
U)
g
i
u
2
5
s
TABLE 2. TREATMENT CHEI
>.
o
c
• Jt Jf * *
|i O C CO
1 11 11
3
c c
c2 e2
• So 2o
& §1 %l
1 S If if
e CM €> > O *
J *• $ ~. J *
£ TJ CTCM O-CM
< g CM ^ CM ^
1'
1 »'
c W
»lll
1 1 .8 8
t- 3 to at
,0
I
|S
? i
o i
& *
Principal Ingredients
Chamlcals Uwd In I
Poly loxyethylene- (Dimethyliminio) Etl
(Dimethyliminio) Ethylene Dichloridel
Disodium Ethylene Bisdithiocarbamate
Sodium Dtmethyldithiocarbamate
Ethylene Thiourea
* *
§0>
O
C *"* ^
B •" *••
* 1 1
H ^ §
.*• o o
H u. £
a
^
lontinuoi
u
1
o
cf
J
Scale/Corros
Inhibitor
Sodium Hydroxide
Methylene Phosphonic Acid
in
in
O
CM
•I
E
£
•o
c
a
a _
3 c
i-§
"i
< e
t!
« »
E §
'1=5
S. ""
18
•
Dispersant/
Antifoulant
3
Q
<3
Potassium Hydroxide
1 -Hydroxyethylidane-1 , 1 -Disphosphon
8
CM
r-
10
3
'E
£
4_
O
1
<
E
•>
2"
"S
O)
? §
"S "~"
' 1>
i ">
i
t-~ C
2 S
&K BB
ding* 8P4B. !
Non-Acid Dei
i
1
(2
0
J
Chemical* Usad In Coo
Sodium Hydroxide
c
0
g
0
e
a >
3 >
C •-
I 1
U O
i i
& ^
a, «-
"e
o>
Q
C! *
1 II
I ^ E
1
u
o
ca
o
c
£
Poly (Oxyethylene- (Dimethyliminio) Eth
(Dimethyliminio) Ethylene Dichloride)
CD
X
0
o
o
w
1
o
- o
o
^~
7
CO
O
ii
CM 5
s i
.. j<
5 a
c
ffl
2,2-Dibromo-3 Nitrilopropionamide
o
CM
X
0
^
c
a
Q.
t start-u
lutdown
< •>
E
~S
O9
fl .
01 2
5^1 a
o
2-
o
o
<5
5-Chlor-2Methyl-4-lsothiazolin-3-One
2-Methyl-4-lsothiazolin-3-One
CO
CM
X
O
* „
3
O
I
u
a
3
a
E
_
CO
1
2|
? I
c
o
Scale/Corrosi
Inhibitor
w/ Bioclde
0
|
Sodium Molybdate
Poly loxyethylene- (Dimethyliminio) Eth
(Dimethyliminio) Ethylene Dichloridel
^S
lj
0
o
o
e
3
O
3
C
C
o
U
a
3
•g
E
CO
1
«•-> *
26
CM a
^ S
c
o
Scala/Corrosi
Inhibitor
w/Biocide
i
c
£
Poly [Oxyathylene- (Dimethyliminio) Eth
(Dimethyliminio) Ethylene Dichloridel
o
6
8
g
e
Q_
|j
M t
°- c
£! •
Dispersant/
Antifoulant
Not Available"*
X
£
c
1
of treatment.
S .
o c
1 1
0 >
«£ *°
• I
o c:
~ £
c •
/ alternated on a weekly basis, to increas
iding on system load.
i are listed as proprietary information and
= s s
ils
S"£l
sit
> "^
lit
o 2 •=
2 ° it
3-6
-------
Chemical
Biocide
Scale/Corrosion Inhibitor
Dispersant
Descaler
TOTALS
Annual Annual Cost
Usage ($/yr)
(Gallons)
34
608
144
28
814
$660
$9,909
$1,971
$1,336
$13 876
These units have automatic controls in place to measure conductivity, and they automatically
open the tower bleed valve when TDS measures greater than approximately 600 ppm Chemic ifs
are admimstered by an automatic metering pump. The pump is designed to remain c.osedThS the
tower bleed valve .s open to minimize shortcircuiting of chemicals through the system Theb\e<*
water from both towers at building V53 is directed to a comer roof drain which is believed to
discharge through stormwater outfall no. 077 (previously no. 112; see Appendices B and C)
Chemicals used continuously in these towers include a biocide and a scale and corrosion
With biOCide. A rlicnnn-ant -sn<4 H«»»~l_, L.-.H- , . wwnwaiwn
shutdown or
3.3.4 Buildings SP29 and U16
™n . The C00"n9utOWerS 8t buildin9s SP29
-------
SECTION 4
OPPORTUNITY ASSESSMENT
4.1 SURVEY AND DESCRIPTION OF AVAILABLE OPTIONS
Three alternatives for cooling tower water management and treatment have been identified
during this PPOA: no treatment, chemical treatment, and non-chemical treatment Table 4 orovides
a brief description of methods available for the control of scale, corrosion, and biofouling includino
traditional and more innovative treatment technologies. In the subsections that follow ten
treatment options are presented, as they apply to these alternatives.
4.1.1 Non-treatment Alternatives
Although non-treatment alternatives may eliminate the application and subsequent discharge
of cooling tower water treatment chemicals, the result may be an increased water usage rate to
control the accumulation of suspended solids in the system. In addition, improper treatment and
management of cooling tower water may result in an excessive buildup of scale deposits and
biological fouling that will ultimately result in system failure.
4.1.1.1 Option 1. No Treatment--
Many of the NAS cooling towers currently have no formal chemical treatment program One
option for pollution prevention is to extend this practice to all 28 NAS cooling towers. Under this
scenario, the towers would receive annual maintenance as described in Section 3 During the off
season, the units would be externally cleaned with wire or nylon brushes, the heat exchanaer end
plates would be removed, and the tubes would be reddened with a round wire brush to remove
scale deposits as needed. Approximately one gallon of algicide would be added to each unit bv
means of a drip feed.
' Refraining from chemical treatment would result in the annual consumption of approximated
28 gallons of algicide at a cost of approximately 15 dollars each, for a total of $420 00 per year'
This represents a savings of approximately $13,300 dollars annually in chemical costs and a "
substantial reduction in the discharge of cooling tower water treatment chemicals to the
environment. However, failure to property maintain the towers during the operating season results
in the buildup of scale deposits and significant algal growth. This will lead to operational down-time
for the repair work and mid-season cleaning. This is costly in terms of employee man-hours In
addition, the operational lifetime of a unit, typically in the range of 15 to 20 years, is significantly
reduced by improper maintenance and also by failure to provide adequate corrosion protection
Systems clogged by excessive scale deposits often require acid dosing to clear blocked
passageways. This is an aggressive treatment procedure and can be harmful to the materials of
construction, especially where corrosion has already exposed oxidized portions of the metallic
surface. Thus, while a no-treatment option appears to be cost effective in terms of operating
expenses, ultimately, the excess capital expense of new equipment purchases due to system failure
makes this option less attractive. •anui«
4-1
-------
i
s
Sir
S
fr-
it:
tu
K
<
35
0
C
i
8
o
«
p
z
s
5
1
°
s
CD
<
v»
1
E
I
„
•o
J
I
7£
g
i
•o
2
o
S *
if
ii
is
£
J
3
i
•n
c
o
'«
o
i
o
o
Tg
.£
>•
a
«
•O
o
c
E
a
c •
1
"o
a
w
o
I
§o
0
•- i
c •§
3 5
•» •
c §
o> —
. B
£ C
'S B
3 1
c . E
i !
£ c 1
} 1 i 1
£ o « «
£ » N .a
*o o o> "«
«.£.£«•
oi I -S
a £ £ •£
$ W W Q
m
o :=
.-S ' 8 S
" -o 2
1 1 ?
*
S g5 g -
o | - g £
^|z-ss
-o .2. c g .2 c
!<'Mi«
im_si
O «- M (0 (Q C
l»:jgs
ifs^ii
f 2 ~ o> o 5
§ill'5§
2 E 8€ g 8
^ssjff
I - S « S § 5
figlis!
HI § Hi
"^li-sll
Isljs^j
"5 _-.*.S S °-
^llfjll
.ijll^ll^
ills|-t|
l«lll||l
|gji=.sss
s ° s " * 5 J-
c .n *£•-•-« o
|| 5 l| o>~|:
lHi!|8f
S5»5SS^|
•sil'f fc-I*
5,§:-£°.I£i
llpllli
| ° S 1 c
> w * ^ ^
ll-fss
Mtu
o -co
» si IB
it«h
|1|lf«
Ii ll II
mill
•g
o
-H §.«»
slg
o>« a>
|i
|i
lll«.
if!
1
4-2
-------
«»3
m
Q7
C
o
_«
uj
**^
09
iS
Comments
T3
i
c
o
i
a
«
*~
•a
S
*
0
O A
a o
•0 «
c t
W 3
Ji O
-a o
O •!
Successful for muddy waters. Material contains highly
charged particles which attract mud, causing flocculence.
The mud is carried through rather than adhering to surfaces
in the system.
«
c
JO
OJ
o
0
c
«3
O
"5
1
c
•1
Dissolved solids concentration maintained at required level by
continuously bleeding off a portion of the recirculating water.
Some forms of treatment require a greater bleed-off than
others. Harder water requires a lower concentration factor;
higher values are accepted with certain types of treatment,
notably those with a filming action. Concentration values of
about 3 to 7 are enough to cause some salts to precipitate
out as scale.
c
|
"§
.2
5
~
'
o
m
Anodic inhibitors function either by forming a film on the
metal surfaces or by chemisorption on to metal surfaces.
Chromates are used most frequently but they are toxic.
Chromates form a thin passivating film directly on the
anodes. Dosage depends on nature and location of dissimilar
S
»
1 (jT .
* £ S
ifl
ill
*S ^O at
o o. o
> cs.e -
g g|-S
.55 -2 •£ g
metals temperature, salt content and the ratio of metal
surface area to volume of solution. High concentrations are
^
2
0
c ?
i g^
» £
necessary when Chromates are used alone. Polyphosphates
form a protective iron-orthophosphate film which also helps
to prevent carbonate deposition on metal surfaces.
Polyphosphate reverts to an orthophosphate with possible
precipitation as complex calcium phosphates, depending on
calcium and orthophosphate concentration temperature, pH
and total solids concentration. Silicates require close pH
control, which should be maintained between 6.5 and 7.5.
High concentration lead to precipitation of calcium silicates.
Nitrites require high concentrations (200 to 500 ppm) and
close pH control (7.0 to 9.0). Nitrites decompose and results
in serious corrosion at pH less than 6.5 and are subject to
conversion to (ineffective) nitrates by nitrobacteria.
Form adhering, insoluble hydroxides at cathodic areas and
cause cathodic polarization. None are practical corrosion
Inhibitors when used alone.
o
o
c
o
'o
tt
S E
«~
O o
1-
o £
fl
« "1
u g
C jg
l!
£ E
Chromate component is effective but toxic. WHen omitted,
higher dosages are required.
0?
e
J
*
u
a
t
O
f
Q.
-------
B
C
e
I
e 73
r- ^
£-S 'f •
available which contain neit
tes. Usually used at higher (
an is customary to be used \
ten formulated for a particul
ange.
Some formulations are
chromata nor phospha
and lower pH levels th;
chromates, they are of
system and operating r
if e
* -X
o a
•J 3
"2 S o "5
e •" *J 09
reversion to orthophosphate
ies of polyphosphate are us«
tential. Combinations with 2
the stabilization of this ion ir
Corrosivity is reduced:
scale-inhibiting properti
control high scaling pol
introduce a problem in
form at high pH.
.s
5
i
U
tj
S
1
~
5
a
c
o
«3
!
U
CD
O
IB
•*
."!>
«
a
'c
"a
.1
1
|
3
JE
_£
U
1
U
fll
O
I i
= 1
•^ V
!«
Is
S§
ll
a c
0 I
S2
c £•
•9-5
c —
o o
(0 c
.£
o
1>
II
^-2
o u
J-2
"3
-rs
•Si-
o a>
5
09
K
O
•&.
i&
Ul
OJ
o
I
i
a
is
JO U
'£ (Q
.£ .2
o >•
i °
ro-S
6 S
.£
o
u
>.
S
o
'E
o
a
sM
IS
II
o
a
•o
a
oo
a.
o
J-I
a .t:
_ T3
JD
03
U
«)
I
T3 "•
= °
2 "§
c •£
o a
(j (j
-
o
I
5
1
O
O
I
.c
_0
U
8
E
o
|
* » -s
III
® 5 £
* t3 "
3 (0 >
O QQ 3
1
M
!Ǥ
Isl
o JS>.S
•
J2
a
I
4-4
-------
11 .-S.O I gf = l|-.2
o O ir 5 >r
UJ
_l
co
!!« I Hi! ,!M, fii!! -ri
ilKliS * It!1:' sjjis fii|!
i fin* mil $m
iitln! i lilt n\a lint
?is2s:s i =issj 558=? s«.i
I i.:«i
ma i $s
iFiiil i HJ«
i i ilfll SSsE- §«*s
I IliP.lil BJH «|ill il-=i
« Hill |!i!l illls «™,..
•o o cf: j£ a j- o o «3.22^ SC«OL? ^Boo^ia 4-riO$3So
SB! lliU lift!
ifttif!!! ««! JIIH iJili
uu
Z
I Sg «|»|| i^lll 2B»M| |5fs|QI| I
o3 Si
El
si s . • • « c § -i
Ii i I -s .2 • i*
5S S • 5 ^ ll
~i 1 « « s "-0
§| S -2 £ . .. i |S
«i= • S g g * I?
o S I c £ i JJ *
J» S 5. a 1 J_-
5 I ! ! 1 ?!
o »•> I- g._
§ S •« -5 S°
JJ •= I ' "? ?g
» o ra « u.E
^ -S 5 S o^
o- uj S a ^s
4-5
-------
TABLE 4. (CONTINUED)
1
O
N£
0 0
•si
c.2
E£
Comments
Corrosion inhibition is achieved by cathodic protection provided by the less noble
in solution are available to react chemically or cathodically. The effectiveness of
corrosion inhibition is questionable.
in Cl
.10 o
•'S
•3 =
*Z
c u
5 «
fl C
£ 2
"* C
11
1 -
^5
1
e
c
B
O
T>
a
B
u
ft
"(5
o
o
I
o
•o
0
£
o
o
c
u
1
Ti
|
u
a
.2
u.
O
c
a
I ^
1 ||
°S"=1
C-S 2
•5.00
>-«O £
This describes corrosion detection using nondestructive test methods includmg h
corrosion probes. Hydrogen is a by-product of most aqueous corrosion processe
evaluation cannot locate corrosion but can predict approximate corrosion rates.
detect and measure corrosion at a given point, can estimate total amount of co
corrosion anticipated.
§
'M
0
O
u
£ £
"If
ca
If
wl
T|.£
O a
a Z
Wro
S in
0.2
$5
HO.
0
~^"5-
s|?.l
a-l'5.l
£-°2o
=o 5:5
a D u c
The saturation index (Langelier equation) is the difference between the actual me
calculated pH at saturation with calcium carbonate ( > 0, scaling; <0, corrosive;
stability index (Ryznar equation), has an optimum valve of 6.6 (6.5, scaling; 7.0.
ideal). It was developed to provide a closer correlation between the calculated p
quantitative results obtained in the field.
o
c
E
|
a
As with pH adjustments techniques, characteristics at one particular point in the
accurately reflect conditions at a point further downstream.
Hi
ZE2
l^s
ifl
II3
^ 1Q>~.
ists mainly of calcium and magnesium in the form of bicarbonate or temporary hi
s can be eliminated by boiling the water to transform bicarbonate into insoluble c
ter after boiling. Temporary hardness does not take into account the presence o
jonate remaining in the solution.
n » 5 —
c e $ a
8-i o
01 a "S £
W w B O
5 2 5 5
— o !S «
ifM
B.*! ~
c1" = o
_ 3 o>
11
w to c w
C — C-C
" i " —
|i||
I S'i 1
E IA oa.
•gS — S
S«|-|
« io 3 c "»
I IlII
n
con
2 B OC
«- C ** £
H £ <• *
§ Sj2-2
|i»l
Hi*
kaline by heating, or to attack metals corrnsivly, depends on the balance of the
eratures is usually due to temporary (bicadior lu) hardness being converted mto
sufficient to result in calcium carbonate saturation. The solubility of calcium carl
n water is greatly reduced as the saturation < (iiilibrium is approached. Ideally, ai
nd carbonate) are so balanced that they caii.-.t: neither scale nor corrosion.
e Ot >.'" "
C £ C *
O w .— » -Q •*
"Q v C •— S
*- Q d O c
la ™ ^ ®
i 1 * c"2
•g^-— ^ S
c * SB^
"gfeS-go
ts g ^ 5o
5 CMC
||l||
O*- * ^_"x
~-a s~~
£ O CT-j^
5W|||
555 fj g
o*g.oO
ol = Ce
S £ 5 ™ 0
'1— o.S "«
illli
4-6
-------
4.1.1.2 Option 2. Continuous Bleed-off or Slowdown-
The purpose in using recirculating cooling systems is to conserve makeup water. Systems
using higher cycles of concentration use less water. Achievable cycles of concentration depend on
the concentration of ions such as calcium and silica in the makeup water, since these ions and
dissolved solids accumulate throughout evaporative losses which take place in the cooling tower.
The risk of severe scale or corrosion problems increases dramatically with higher cycles of
concentration. Solids and impurities will continue to accumulate until the system water is removed
through bleed-off or blowdown. Dissolved oxygen increases in a recirculating system because the
water is aerated during each passage through the cooling tower. In normal practice, a portion of the
recirculating water is removed through system blowdown in order to maintain the concentration of
dissolved solids and gases at a required level, thereby preventing scale deposits and corrosion.
The maximum concentration factors are defined for open cooling water systems according to
the hardness of the water and the type of treatment applied. Systems receiving makeup water of
relatively low hardness or those which receive effective scale-inhibiting treatment may operate at
high concentration factors, thereby maximizing the portion of recirculating water and minimizing the
makeup water requirements. Without treatment, concentration values of about 3 to 7 are enough to
cause some salts to precipitate out as scale. Various water treatment approaches and device:* have,
historically, avoided scale formation by increasing the bleed and makeup water rates rather than
controlling calcium carbonate or silicate formation by chemical or mechanical means.
Minimum dissolved solids and mineral concentrations could be maintained by operating the
cooling tower with a continuous supply of fresh water and a maximum flow of tower bleed. A
once-through system would avoid the buildup of solids, gases and impurities in the process water,
thereby limiting the potential for scale deposits and corrosion, and would eliminate the need for
administration and discharge of chemicals to the environment through cooling tower blowdown.
However, the high operating costs incurred by purchasing large amounts of makeup water make this
a fairly unattractive option. Makeup water requirements and associated costs are reduced drastically
by operating at higher cycles of concentration.
To illustrate this point, consider a 100-ton cooling tower operating at 100 percent capacity for
12 hours per day. Assuming a 10°F temperature differential across the tower, this tower will
circulate approximately 300 gallons of water per minute and approximately 3 gallons per minute
would evaporate. Thus, operating at one cycle of concentration, the makeup water requirements
would be approximately 18,000 gallons per hour, or 6.5 million gallons per month based on 12
hours per day of operation. At a combined water and sewer cost of $3.40 per 1000 gallons (based
on City of Norfolk 1994 water and sewer rates), this type of operation would incur a monthly
operating cost of $22,000. Operating this same tower at 2 cycles of concentration would
substantially reduce the makeup water requirements to 360 gallons per hour, or 130,000 gallons per
month, representing a monthly cost of $443 and a savings of 98 percent. The effect of increasing
cycles of concentration on water consumption and associated costs is presented in Table 5.
Although a continuous bleed would help to reduce the buildup of dissolved solids and gases,
the potential still exists for algal and bacterial growth. Thus, the system may still malfunction
during the operating season if biofouling is allowed to progress. Each cooling tower unit should still
receive an annual overhaul and an application of a one-gallon biocide drip, which will increase annual
operating costs accordingly.
4-7
-------
TABLE 5. BLEED AND MAKEUP WATER REQUIREMENTS AND ASSOCIATED
MONTHLY COSTS AT DIFFERENT CYCLES OF CONCENTRATION*
Cycles of
Concentration
Evaporation (gpm)
Total Bleed Rate
(gpm)
Makeup Water
(gpm)
Water Cost
<$/month)*«
2
3
3
6
$443.09
3
3
1.5
4.5
$335.07
4
3
1
4
$297.84
5
3
0.75
3.75
$279.22
8
3
0.4
3.4
$253.16
10
3
0.33
3.33
$247.95
16
3
0.2
3.2
$238.27
•Assumes a 100-ton open-system recirculating cooling tower operating at full capacity for 1 2 hours per day
with a 10 F temperature drop across the tower. Pump circulation rate is 300 gpm.
H?«^l"« ™?1^ * ?,°mbined water and S8wer cost °f '3.40/1 000 gallons. Norfolk City water prices ar«
currently $1 .34 1000 gallons, and sewer prices are $2.06/1000 gallons. Since cooling towers at the Norfolk
WAS are generally not provided separate metering systems for drainage, combined rates are charged for makeup
rdischa±T*°d 'T ^ f' "* ** Of>eratln9 CyC"S °f c°"c«"™'°" increase. L volume o"
t for tZl ^ tl" 'S.substan"a"y reduced- Separate metering systems would allow calculation of »
ta °t aTsavT " "*" d'SChafged tO *' drain <«-9- "v.porative losses), and would result in
substa t asav
.4.1.2 Chemical Treatment Alternatives
-, t *>• : addltlon of cnemica|s to control corrosion, scale deposits and biological fouling represents
a traditionally acceptable method for cooling tower water treatment. In an adequately monitored
system, chemical dosage rates can be adjusted to maintain proper system operation efficiency
However, the possible storage and handling of large volumes of chemicals represents a potentially
dangerous s.tuation for maintenance and operating personnel. In addition, increasingly stringent
lim.tat.ons on the composition of sanitary and storm sewer discharge streams require close
monitoring of water treatment chemical constituents. The Hampton Roads Sanitation District's
Cooling Tower Waste Discharge Policy and Industrial Wastewater Pollutant Limitations are presented
in /Appendix E.
4.1.2.1 Option 3. Conventional Chemical Addition Programs-
Chemical treatment programs have been instituted to enable cooling tower systems to operate
at increased cycles of concentration, thereby conserving water use. As discussed in Section 2
most chermcal additives for scale control function essentially by increasing the capacity of the '
process water to carry dissolved solids, allowing higher concentrations of solids to remain in
solution rather than depositing out as scale, while corrosion inhibitors function primarily by forming
a protective film on the metal surface. Historically, chromates were used to prevent corrosion under
o?oI*£>Unl*rS bf f US^Chr0r[!f,*lS afe 9°°d Oxidi2in9 a9ents ln acid^-and react to maintain a film
of ox.de on the metal surface. Wrth an acid feed to maintain a solution pH between 6 and 7
scaling was not a problem due to the increased solubility of calcium carbonate at low pH. '
Environmental concerns led to the ban on applying chromate to comfort cooling towers
r^rrTV" F8?Ua7 and MaY °f 1"°
-------
agents or polymeric materials are typically added to counter scale formation. Section 2 discusses
the chemicals used in cooling water treatment applications.
Although the majority of cooling tower water treatment chemicals in use today have been
formulated with environmental safety in mind, almost every chemical used for water treatment can
be harmful or environmentally detrimental under certain circumstances. Phosphorus is typically a
primary component of commonly used corrosion and scale inhibitors, but it is an environmentally
sensitive compound due to its potential effects on ecosystems and its contribution to algal blooms
and entrophication. As shown in Appendix E, the discharge of phosphorus in cooling tower
blowdown is subject to a surcharge when the concentration exceeds 6 mg/L.
With increasingly stringent regulations governing the quality of discharges to sanitary and!
stormwater sewers, the composition and quantity of chemical cooling tower additives have become
a primary concern. The chemicals' effects on the operation of the Base's wastewater treatment
system and their environmental acceptability in the wastewater discharge should be considered.
The ultimate fate of the cooling tower discharges is currently unknown. These drains may lead to
the sanitary sewer, or they maydrain directly to a stormwater discharge point. These uncertainties
exacerbate the need for stringent environmental controls regulating the applied treatment chemicals.
Blowdown or tower bleed which flows to aquatic systems and drift to the terrestrial landscape carry
applied chemicals to locations where natural biota can be damaged through direct poisoning or
where toxins can accumulate to potentially detrimental levels as they are transferred through the
food chain.
By their nature, microbiocides used to control biological fouling exhibit toxic and
environmentally harmful characteristics. Increasingly stringent regulations regarding the composition
of discharge streams draw attention to the proper handling and application of these chemicals. The
use of non-toxic or environmentally friendly alternatives, when available, is always preferred.
Depending on the characteristics of the system, mechanical cleaning may represent a viable
alternative to chemical treatment for control of biofouling and possibly scale deposits. Either
brushes or abrasive-surfaced balls can be forced through piping systems to scour away deposits.
Additional non-chemical treatment alternatives may also be applicable, as discussed in Options (5
through 10.
4.1.2.2 Option 4. DIAS-Aid Tower Treatment XP-300 »
The chemical scale and corrosion inhibitors currently applied to treated towers at the NAS
generally consist of proprietary mixtures of phosphonates, phosphates and molybdated phosphates,
nitrites, and polymers, as shown in Table 2. The tendency of these traditional materials to bond
with and hold calcium, magnesium and iron is relatively weak and easily interrupted. If the makeup
water hardness increases or the cycles of concentration are increased, control of the metallic
constituents is lost and scale deposits form. This can be counteracted by additional chemical
dosages or a reduction in the cycles of concentration.
A new generation of water treatment products is available which will reportedly enable cooling
tower systems to operate effectively with zero bleedoff throughout an entire operating season.
DIAS-AID Tower Treatment XP-300, manufactured by DIAS, Incorporated, is an innovative chemical
agent designed to control scale and corrosion under virtually any hardness conditions. The MSDS
for this compound is included in Appendix F. XP-300 consists of a proprietary mixture of several
environmentally-safe, hydrolytically stable chemical compounds that interact synergistically and
selectively with calcium, magnesium, and iron ions in solution. The mechanisms for scale and
corrosion control include threshold stabilization, sequestration, and crystal modification. In its
4-9
-------
concentrated form, XP-300 is an acid-based material. The acid blend has very little effect on the
The effectiveness of XP-300 relies on the fact that scale and corrosion are both related to
changes ,„ the molecular bonding of heavy metals. In the normal cycle of change which takes olace
« ZlZTx?3^^C]Um' m89n!f ^ 8nd ir°n !0nS b°nd With other efem^f^
compounds. XP-300 ,s stable m water and has a stronger affinity to heavy metals than the other
elements these metals normally bond with, resulting in the formation of a strong chemical bond
between the molecules of XP-300 and the ions which are otherwise likely to pr^Sl out as
at a ratio" SSSSita? T f^'' *"**" b°nd''n9 maten'a'S WhiCh b°nd ^ **™*^*
d!s oTvS app;°achin9 one » ten' one mo'ecule of XP-300 will bond with over 3,000 molecules of
'°nS SUCh 8S Calcium' ma9"esium, and iron. This high bonding ratio allows the
* remahl C'6an With°Ut f«*™»* th* additi°n
systems treated with xp-300 can
made fothon tr,f atment chemical does ™» contain a pesticide and no claims are
fTe'fteStin?Derformed bl'S 25 > °T*1 contamination- However, experimentation and extensive
^olo^ara^^ n\ ' C< T* Sh°W" that When proper treatment levels ™ maintained,
^^^r^.^LS8** water'-Sal spores wi" create a bloom- and bacteria- fun9j' and
^M^J^SSST" p s process could continue until the fiystem is free of a
300 ?Jth0 K , ? 9 rowth 'S Present in a system' jt cannot be controlled by adding more XP-
3,00 rathe r a b.olog.cal control substance must.be used to correct the situation Oxidizing aqerts
such as chtonne ar. norma.lv added for a period of 24 hours to Bt
Pf8SenCe °f Str°n9 °Xidi2ing 8gentS and must be
dUri"9 the inltial phases of treatment wi^ XP-300. Large
Diecesf -. arg
' bnla^looI'e ff°m the '"terior surfaces and plug dispersion holes or
durin9 the initiai cieanup process if scaie
°IAS'AID formulation sev«*al years ago for use in large tower
^
provided the chemical remains at the desired
HV "^ " bi°'°9iCal 9rOWth d°es not devel°P' as descril>e
-------
as with all cooling tower water treatment chemicals, tower blowdown containing XP-300 should not
be discharged directly to the storm sewer. Given the uncertainties surrounding the constituents of
XP-300, and the increasingly stringent limitations for contaminants discharged to both sanitary and
storm sewer outfalls, this chemical should be administered following the same precautionary
guidelines which are applicable to any of the cooling tower water treatment chemicals discussed
above, in Sections 2 and 4.1.2. .
DIAS tower treatment chemicals are currently used by a number of facilities to treat cooling
towers ranging in size from 50 to over 500 tons. The treatment program appears to be
operationally and cost effective. Most of the contacted facilities that use this method of treatment
reported substantial savings in chemical costs, some by as much as 50 percent (Mr. Robert
Johnson, Four Seasons, Provo, UT School Systems, personal communication, 1994.). In addition,
makeup water and tower bleed were substantially reduced, in most cases to a "slow drip" and in
one instance, at an older tower (1967 vintage), to zero bleed for the entire 5- to 6-month operating
season (Mr. Safet Hatic, Hatic Heating, Cincinnati, OH, personal communication, 1994.). Most of
the contacted facilities maintained seasonally operated cooling towers associated with comfort
cooling systems, and had used DIAS chemicals for periods ranging from 2 to 6 years.
While most facilities reported that they had no problems with microbiological growth as long
as the towers were protected from sunlight, one maintenance facility which uses DIAS chemicals on
a number of towers ranging in size from less than 50 tons to over 300 tons implied that they heive
experienced occasional down-time due to fouling. The problems described had been infrequent and
were easily overcome with a one-time application of biocide. This particular maintenance facility, in
fact, recommended the DIAS chemicals for application on towers which receive little or no attention
throughout the operating season (Mr. Peter Gruener, York International Corp., Troy, Ml, personal
communication, 1994.). A separate facility which operates an older tower reported using a small in-
line filter to remove debris which had entered the system's water from a nearby construction site
(Mr. Safet Hatic, Hatic Heating, Cincinnati, OH, personal communication, 1994.).
4.1.2.3 Options. pH Adjustment-
The problems of scaling and corrosion are related phenomena, both being influenced by the
properties of calcium hardness, alkalinity, total dissolved solids, pH, and temperature. Theoretically,
these conditions can be controlled so that the water is in equilibrium and neither corrosion nor
scaling result. As demonstrated by the Langelier Index, a high pH encourages calcium carbonato
scaling, while low pH facilitates corrosion. Adjusting the pH of the water to provide a Stability
Index or Langelier Index which is neither scale-forming nor corrosive is one method for stabilization.
Adjustment of pH is generally accomplished by adding acid, typically sulfuric, hydrochloric, or
nitric, to sufficiently depress the pH in order to prevent any scaling conditions from developing.
Problems associated with this method of scale control are related to the resulting increased
corrosivity of the water. Hydrochloric acid tends to increase the corrosion rate more than sulfuric
acid, although both hydrochloric and nitric acid allow high salt concentrations in the water because
of the greater solubility of chlorides and nitrates. Sulfuric acid is commonly used for pH adjustment.
Injection of sulfuric acid converts calcium and magnesium carbonates (carbonate hardness) into the
more soluble sulfates, but acid dosages must be monitored to ensure that the concentration of
calcium sulfate remains below the saturation level to avoid precipitation and consequently, scale
formation. The prevention of scale formation also requires limiting the concentration of total
dissolved solids in the system water. This is accomplished by maintaining a controlled continuous
bleed or intermittent blowdown of a small portion of the circulating water. Acid requirements can
be calculated based on a simple equation which accounts for the composition of the makeup water
(including total sulfate concentration, alkalinity, temperature, and operating cycles of concentration).
4-11
-------
The acid is usually injected as near as possible to the makeup water intake, and is controlled by an
electric motor connected to a pH analyzer installed to the cooling water supply header.
Adjustments in pH must be made based on a given set of environmental conditions at one
point in the system, most typically following the makeup water intake point. As the water passes
through the system, the environmental conditions may change to some degree and the water may
become corrosive or scale forming. Frequent testing should accompany any acid dosing program
because the amount of acid used must be limited to maintain some residual alkalinity in the system
Reducing the pH below 7.0 would result in accelerated corrosion. In addition, the essentially soluble
compounds of calcium and magnesium formed from acid dosing cause a corrosive condition
requiring close system monitoring. Corrosion inhibitors are often used in conjunction with pH
adjustment to stabilize the water. A typical pH adjustment program involves adding sulfuric acid to
lower the system pH thereby reducing scaling tendencies. This program should be accompanied by
an inorganic or organic/inorganic corrosion inhibitor.
Adjustments in pH can also be made to prevent corrosive tendencies, while being
supplemented with chemical additives for scale control. Maintaining a pH of 8 in combination with
the addition of polyphosphate for scale control reduces cqrrosivity and inhibits the conversion of
polyphosphate to the relatively ineffective orthophosphate form. Combinations with zinc introduce a
problem with respect to the stabilization of the zinc ion in soluble form at high pH.
One environmentally attractive option involves adjusting the pH and composition of the water
to deposit an eggshell layer of calcium carbonate, which would protect the underlying metal from
corrosion without interfering excessively with heat transfer or water flow. Temperature variations in
the system result in variable composition of the water, however, preventing uniform protection of
the metal and allowing some sections to be subjected to heavy scale deposits. Additionally, surface
and water conditions often lead to the deposition of a porous layer of calcium carbonate, instead of
the desirable eggshell film. The porous layer significantly reduces heat transfer and promotes
localized corrosion (Encyclopedia of Chemical Technology, Volume 24. 1984). For these reasons
this method of treatment has generally been unsuccessful.
In theory, cooling tower water treatment through pH adjustment represents a fairly attractive
alternative, since this method of treatment avoids the addition of organic and inorganic
contaminants potentially present in conventional water treatment chemicals. The tower blowdown
should neither be high in acidity (corrosive) nor alkalinity (scale-forming), and should be safe for
discharge. In practice, however, this method requires a high degree of system monitoring to
maintain the pH within a relatively narrow, ideal range for proper operation. The potential for
I^rrSc16 fj^"ent is Si9nificaunt, due to the narrow range of acceptable operating parameters and
variations at d.fferent points with.n the system. As discussed above, a typical pH adjustment
scheme involves the addition of supplemental chemicals for control of scale deposits and corrosion.
4.1.3 Non-Chemical Treatment Alternatives
Non-chemical methods for cooling tower water treatment typically involve the application of
physical mechanisms to control corrosion, scale deposits, and biological fouling. The treatment
I™ f°?HeS described below vafy wide|V ln terms <>f cost effectiveness and reliability. In addition,
some of the treatment technologies may primarily apply to only a certain type of problem either
scale, corrosion, or biofouling, and may not represent a comprehensive treatment program
However, all of the non-chemical treatment alternatives minimize the generation and discharge of
contaminants since the addition of chemicals is avoided.
4-12
-------
4.1.3.1 Option 6. Zeolite or Base Exchange and Ion Exchange Processes-
Non-chemical methods of water softening can be used to control scale deposits by removing
dissolved mineral components while simultaneously avoiding some of the undesirable consequences
associated with chemical softening techniques such as high salt concentrations and increased
corrosivity. Zeolite or base exchange and ion exchange processes are based on the exchange of
harmful constituents in the water for less harmful components. A softening plant of this type
requires careful consideration of the quality of water entering the softener because the bed of
exchange material will be adversely affected by the presence of suspended and dissolved solids
which may precipitate from solution. Also, depending on the characteristics of the intake water, the
soft water produced may be somewhat corrosive in nature and the system may require additional
corrosion protection. High bicarbonate concentrations in the makeup water will cause a rapid
increase in alkalinity subsequent to passage through the exchange bed.
Although they eliminate the discharge of treatment chemicals, zeolite and ion exchange
processes are generally quite expensive and require a significant power source for operation.
Additionally, these units are used for scale control only and may increase the risk of corrosion.
4.1.3.2 Option 7. KDF Process-
As part of an innovative, non-chemical approach to cooling tower water treatment, Water
Equipment Technologies (WET) has developed a process which utilizes a metallic alloy for the
control of corrosion, scaling, and biological fouling (Stenger and Dobbs, 1993). The alloy consists
of a special formulation of copper and zinc, and is referred to as "KDF" (kinetic degradation flux}.
The KDF process takes advantage of the difference in electrical potential (Eh) between zinc and
copper. The Eh for zinc is -0.76 millivolts, and the Eh for copper is +0.34 millivolts. When
sufficient surface area of the alloy is exposed to water, a redox reaction occurs between the
dissimilar metals, with zinc acting as the anode and copper acting as the cathode. The resulting
electro-chemical reactions and the rise in pH supposedly provide a water treatment process which
controls the formation of hardness scale, biofilm development, chlorine removal, and ionic heavy
metal reductions.
Chlorine is removed through its conversion to zinc chloride. Heavy metals are removed by
plating out onto the copper sites. Corrosion inhibition is achieved because zinc ions in solution are
available and react with corrosive ions. Biofilm accumulation and bacterial growth are controlled by
the formation of hydroxyls, or OH radicals, formed when some of the water reacts with zinc (Zn +
2H2O = Zn(OH)2 + H2). These hydroxyls, along with redox shock occurring as a result of the
electrochemical reactions between the metallic copper and zinc ions, are believed to interfere with
the normal cellular activity of bacteria and algae. Microorganisms are generally limited to survival
within a relatively small range of redox potential. The passage of water through KDF causes a rapid
and reversible reduction in Eh of about 500 millivolts, which results in a disruption of electron
transport mechanisms, possibly causing subsequent damage to the microbial cell walls.
The scale reduction phenomena associated with the redox process media is a function of the
source water quality, pH, total dissolved solids, bactericidal properties of the media, and the change
in redox potential between the untreated source and the redox-media treated water. It is possible
that a shift to a reducing environment disrupts the formation of the crystalline structure of the
mineral constituents. Previously deposited insoluble calcium and magnesium salts are gradually
removed by continuous contact with redox-treated water! The electrochemical reactions interfere
with the crystalline structure of limescale, resulting in the formation of a powdery scale when the
water dries in the splash areas of cooling towers, and no scale deposits on the heat transfer
surfaces. Additionally, the KDF media controls scale formation by inhibiting biofilm formation, since
4-13
-------
biofilm formations provide the mucilage that allows mineral precipitates to adhere to surfaces and
thus accelerates the formation of scale deposits. :
KDF is manufactured with varying proportions of pure copper and zinc, depending on the
application, in several forms including granules, filament or wool, wire or brush, and powder The
KDF wool, where the refined alloy is formed into strands or filament, is used m recirculating loops
and lends itself to cooling tower applications. KDF wool cooling tower treatment equipment is
available in two types of configurations, depending on the requirements of the cooling tower One
configuration uses plastic modules that contain the KDF wool. The modules float in the splash area
of the tower, providing economical treatment by utilizing the hydraulics of the system. A second
design uses KDF wool contact chambers in an external side stream loop to recirculate the tower
water through the KDF wool. Rgure 7 shows a typical system layout for the KDF treatment system
Typical System Layout
Solids Separation
Pump
Figure 7. Typical System Layout for the KDF Water Treatment System
A separator is recommended to filter the hard scale and solids removed from the tower and
piping system by the KDF wool. Pre-filtration in the 50 micron range is strongly recommended to
reduce sediment loading of the KDF wool media. Recirculating cooling tower water passes first
through a prefilter for solids removal, and then through a KDF wool contact chamber placed next to
and outside the cooling tower water basin, before flowing back into the basin of the cooling tower
Contact chambers are constructed of corrosion resistant Schedule 80 PVC material, secured by
victaulic coupling, and supported by heavy duty aluminum support legs. The chambers hold
replaceable KDF wool cartridges. Contact chambers can be manifolded for obtaining flow rates of
up to 300 gpm. Each chamber has a maximum flow rate of 15 gpm. Each contact chamber
measures 13.5" x 13.5" x 58", and weighs 78 pounds.
4-14
-------
The following factors affect performance of KDF wool systems:
Increased contact time improves performance.
Water should not exceed pH 8.5.
Warmer water temperatures result in more reactive performance; cool temperatures reduce
performance.
Higher total dissolved salt concentrations result in better performance.
Sequestering agents for preventing corrosion or scale should not be used in front of the KDF
media.
• KDF Redox Wool can be cleaned and restored to active life by rinsing in low pH water. The
media should be rinsed with normal fresh water after it has been restored.
• KDF Redox media should not be allowed to dry out after becoming, wet.
The performance life of KDF wool will vary, depending on characteristics of the system and
the fresh makeup water, but it typically lasts a year or longer provided that the water coming in
contact with the media is under a pH of 8.5. Based on studies conducted at 12 Florida test sites,
the average performance life of KDF wool, when applied to systems using Florida water, is
approximately 6 months. Exposure to air significantly shortens KDF performance life, as will
sediment buildup. Spent material may be recycled through local scrap dealers for metals recovery.
The KDF system has been developed to eliminate the use of cooling tower chemicals, and
requires approximately half as many labor hours as a chemical treatment system for operation,
monitoring, and maintenance. This is largely because the system is self-regulated by changes in pH.
Treatment activity increases when in contact with the lower pH makeup water. The increase in
activity serves to raise pH, which tends to stabilize the process until it is exposed to additional
makeup water at a tower pH. A rise in the pH to neutral or alkaline conditions helps to protect
operating equipment against corrosion. The cost of using KDF on a normal basis for cooling tower
treatment is comparable to chemical treatment costs. The normal application rate is approximately 5
pounds of wool for a flowrate of 10 gallons per minute.
A demonstration project was conducted on two existing circular, fiberglass Protec comfort
cooting towers located at a mid-sized hotel in Fort Lauderdale, Florida (Stenger and Dobbs, 1993).
The two towers were rated at 700 and 225 tons, and were regularly receiving chemical treatment
prior to the demonstration project. During the demonstration, the larger tower continued to be
chemically treated by a service contractor, while the smaller tower was treated with KDF wool. The
KDF and chemically treated cooling towers were then compared for corrosion rates, bacterial
growth, and scaling tendencies. Results are somewhat variable, due in large part to mechanical
difficulties, vandalism, and severe weather (hurricane) which disrupted system performance. In
general, the two towers operated at similar cycles of concentration (approximately 4.5 to 5) and
exhibited comparable biofilm development. The KDF system demonstrated slightly enhanced scale
control and corrosion inhibition as compared with the chemically treated system.
In 1993 there were approximately 2O cooling systems ion operation using this technology.
The sites were located in south Florida, Michigan, California, Oklahoma, Sweden, Japan, and
mainland China. KDF systems promote pollution prevention through the potential elimination of
treatment chemicals which are ultimately discharged to the environment. The primary waste
consists of a spent metallic alloy, which may be sold as metal scrap for recycling. However, the
KDF systems have had occasional difficulty in providing adequate control of biological fouling. As a
result, additional biocide applications may be necessary. These biocides would ultimately be
discharged to the environment.
4-15
-------
5 SOUth *0lWa W™ ** KDF System were contacted «** have reported
microbiological fouhng. One facility, which operates two 300-ton cooling towers for comfort
cooling systems was reportedly happy with the system but was forced to discontinue u^e because
of excessive fouhng Service contractors had agreed to administer a periodic acid shock to contro,
b,olog,cal growth. The treatments were never administered and growth continued to doq the
system until fmal.y the KDF was removed and traditional chemical treatment resumed (M? Richard
Conway. Oceantree Condominiums, Singer Island, FL, personal communication, 1994.,
Mm Fi?*6!?01?1!8 reP°rted discontinued use because of excessive growth in the system (Ms
May. Ellen, Abe Schwartz Air Conditioning and Refrigeration, West Palm Beach FL personal
commutation, 1994.,. However, several of the contacted facilities report^ sa^facto^esults
Can t ^ytT l°Uld recommend this trea'™<" methodology to others (Mr Don Murray
Com f? • n^r Mana90emem DiviSi°n' North Bay Vllla9e' FL- Mr- R'chard Need™ Symbioisis
S£') STc'uni^ hTf Ur9r0ff' Hollywood' lnc" Hollywood, FL, persona, communicators
LoPriinJl 'STUhnClear ^at factors maV have contributed to these differences in operating
expenence. The variability, may be due to localized conditions in the water supply As described
above, a makeup water with a PH below 8.5 is necessary for the KDF mediaTfunctfor! ?properij.
WP» ^°St °f K?6 faCuitieS WhiCh exPerienced satisfactory results reported operating costs which
were comparable to those associated with traditional chemical treatment programs in case^where
,HH 1 F S W6re S"9htly hi9her' h°wever' most ^intained that they were wilL to pay the
a
s n casew
S W6re S"9htly hi9her' h°wever' most ^intained that they were wilL to pay the
costs to avo,d the handling and storage problems associated with treirWdSiEi,
4.1.3.3 Options. Magnetic Applications-
place of boner water treatment chemicals. In addition to environmental benefits the neSfo
C°ndfonin9 units consist of magnetic devices which are permanently
ma9netic field' and wi» rem^ '" solutto n
aton thn« < ' '" sout n
Po.yma,ae,c acid. The calcium in this CyC,ed-up system changes into
4-16
-------
flake and aragonite form, a talc-like non-adherent powder, which can be removed using bleed-off
and separation techniques.
When magnetic water conditioners are installed on an earth-grounded steel pipe they hold the
pipe as the generator's negative field or stator. Liquid flowing through the pipe becomes the
positive pole, supplying the electric energy. Not only do the units create a substantial magnetic
field, they also generate a measurable flow of electrons into the water as the pipe becomes
negatively charged. This flow of electrons results in a continuous, cathodically protected system
through which positively charged water flows.
Water is an excellent electrical conductor, and the presence of minerals enhances this
characteristic. As groundwater flows by limestone rock, which form the basis for water hardness
the water carries a positive electromagnetic potential with respect to the rock. The difference in '
potential between water and rock causes mineral salts to dissolve into solution. The water's
positive potential increases the saturation capacity for mineral salts, resulting in high levels of
dissolved minerals in the form of orthorhombic crystals, creating the characteristics of a hard water.
The difference in potential between water and process equipment is the reverse of that
between water and limestone rock. When mineral-rich water enters a piping system, it loses its
positive electromagnetic potential as frictional electricity generated by the flow of water through the
pipe and causes electrons to be transferred from the water to the pipe. Dissolved minerals
precipitate out onto process equipment in the form of rhombic crystals known as scale.
Applying magnetic treatment to water imitates the phenomenon which occurs in the earth
when l.mestone dissolves. When water containing mineral salts flows through a pipe which is
equipped with a magnetic water conditioner, the molecules interrupt the lines of force generated by
the magnet and create a positive electric current and a positive static charge on the water The
magnetic field amplifies the potential in the water to the point where the potential of the water is
greater than that of the process equipment, causing the precipitated minerals to redissolve and
remain in solution. Additionally, as the minerals in the water (calcium, iron, magnesium, etc.) pass
through the magnetic field and generate a minor electrostatic charge, charged iron particles become
a nucleation point for calcium and precipitate out of solution into suspension. This provides a form
of corrosion control because the system is able to operate with a higher level of solids and pH and
has the natural buffering tendencies associated with this mode of operation.
Additional advantages of magnetic treatment include the lower surface tension of the
magnetized water, caused by the polarized water molecules. The performance characteristics of this
water are enhanced such that the water performs like soft water without soft water's typical
corrosive tendencies and turbidity. The lower surface tension is accompanied by an increased
flowrate, resulting in reduced energy consumption and operating costs for the pumping equipment
The magnetically conditioned water will support unprecedented concentrations of dissolved solids '
enabling cooling tower systems to operate with higher soluble mineral content and higher cycles o'f
concentration. This results in overall water savings. When combined with filtration and ion
exchange processes, magnetized water results in enhanced filtering capabilities because the
associations clustering around the suspended particles are broken up as the polarized molecules
become aligned. This creates more solvent fluid flow which impregnates the membrane or filter
medium more efficiently. The higher impregnation efficiency results in higher filtration efficiency
which when combined with the dissolved scaling properties of the water, maintains filter longevity
free of mineral buildup and thereby reduces replacement and maintenance costs
4-17
-------
rnnn-t— followin9 effects are noted by ^e manufacturer of one type of magnetic water
conditioning system which is used at the Naval Base Norfolk:
Pipe becomes negative' the water
The negative pipe receives cathodic protection.
xvntK tW° hydr°9en atoms that are P°sitive s«tic charges and an
oxygen atom that has a negative static charge.
« Positive hydrogen is attracted to the negative pipe and dissolves any scale or corrosion-
hydrogen cannot react with a clean pipe.
» Negative oxygen atoms are repelled by, and cannot corrode, a negative pipe.
« Negative carbonate ions (scale) are also repelled by the negative pipe.
°f W3ter m°'ecu!es' thereb* reducin9
The ionization action also produces hydroxyl ions.
th Watef IS Ca'Cium carbonate, which forms calcite that interlocks
to form hard scale m p.pes. Magnetic water conditioners change the morphology of calcium
n- calcium"
wbarauv ,' eX'"Stin9 C0rrosion and scale accumulations
will be gradually d.ssolved by the newly formed hydroxyl ions, which clean the pipe walls.
repel scale and attract hydrogen which dissolves scale and
a hydrogen film, thus protecting the clean pipe against corrosion.
Positively charged water kills iron algae and other cathodic molds and algae that grow in
showers, swimming pools, fountains, lakes, cooling towers, and petroleum fuels
Sl!S?C WHte- conditioner$ Precipitate suspended solids and compress dissolved solids
thereby producing clear water without chemicals or filters and make softening unnecessary.
three si
PH stabilizes, usually in the range of 7.4 to 8.0, due to the reduction of hydrogen;
the available oxygen {aerobic activity) increases noticeably; and
energy savings occur, because fewer BTUs are required per degree of temperature
change due to more effective heat transfer through clean pipes and equipment.
water T^'T^ SySt6mS e"minate ^e aPP|icati°n and subsequent discharge of
water treatment chemicals, representing an attractive alternative for pollution prevention. However,
4-18
-------
although some of the literature suggests that magnetic water conditioners will provide complete
water treatment for cooling tower applications, in practice they have been ineffective or marginally
effective at controlling biological fouling, algae, and biofilm growths (M. Hegy, Water Treatment
Technologies, Inc., Naperville, IL, personal communication, 1994.). Mechanisms used for scale and
corrosion control are apparently ineffective for controlling biological growth. As a result, the
magnetic systems, like other corrosion- and scale-control systems, typically require a supplemental
treatment program for controlling biological growth. If a traditional chemical biocide program is
instituted, the reduced surface tension of the magnetized water results in substantial reductions in
biocide requirements; 20 to 25 percent of the original biocide dosages have been reported as
adequate when applied in conjunction with a magnetic water conditioner (M. Hegy, Water Treatment
Technologies, Inc., Naperville, IL, personal communication, 1994.). Other possible control
techniques include sidestream solids removal, ozone disinfection, and the application of bromine or
chlorine in a solid tablet form which is delivered by an automated dispenser.
Magnetic water treatment systems have been successfully applied for control of scale and
corrosion at several open-system recirculating cooling towers. More specifically, these units have
been used at over 40 installations in the midwestem U.S. as the primary component in an integrated
technologies program combining magnetic systems with additional technologies for solids removal
and biofouling control. The magnetically treated systems typically operate at cycles of
concentration 25 to 50 percent greater than other systems, and they are accompanied by a 75 to
90 percent reduction in the original biocide application rates where traditional biocides are used.
A magnetic treatment system was tested during a demonstration project performed during the
1993 cooling season on three 400-ton recirculating open-system cooling towers located at retail
outlets in Illinois and Wisconsin. No chemical additives were applied to any of the three towers and
no additional treatment was provided to control biofouling. All three systems performed effectively,
meeting or exceeding the goals of the performance demonstration. Bleed rates were reduced by 50
percent at one location while still operating the system at much higher levels of dissolved solids and
conserving makeup water substantially.
Typically, additional equipment will be installed to operate in parallel with the magnetic
systems to control biological growth and fouling. Successful treatment has been obtained using
centrifugal separators mounted next to the system, through which approximately ten percent of the
system flow is passed for solids removal. In areas where microbial growth is particularly
problematic, for example in warmer, humid climates, the additional protection is provided by a
bromine, chlorine, or iodine float which administers biocide continually at low concentrations on a
self-regulating basis. These units are reportedly simple to operate and cost effective.
4.1.3.4 Options. Alternative Sterilization Techniques: Ultraviolet Light Treatment, Ozonation-
Ultraviolet (UV) sterilization lamps provide a non-chemical alternative for control of microbial
growth. UV systems are generally uneconomical for large quantities of water, but may represent an
attractive option for smaller units. The advantages of UV treatment are that the water undergoes no
chemical change, chemical interaction between the water and pipes is not encouraged as in many
scale-control techniques, an overdose is impossible, no chemical odor is produced, and the
discharge of treatment chemicals to the environment is eliminated. UV treatment is generally more
expensive in terms of capital and operating costs than chemical treatment (Gumey and Cotter,
1966), and is reportedly not a very reliable method of treatment (M. Hegy, Water Treatment
Technologies, Inc., Naperville, IL, personal communication, 1994.).
Two types of UV lamps are available, including one unit that is contained within a horizontal
cylinder which fits into the water pipe, and another that is mounted within an air space and
4-19
-------
irradiates its surroundings. The first type of lamp is recommended for cooling tower water
UV rv?»naH PnCati°nS be°aUSe the SeC°nd apP|ication mav n°t directly expose all of the water to
thmuah wh ,SOme of the water to remain ""treated. The lamp contained within a cylinder
through wh,ch makeup water is passed ensures treatment of all water entering the system
°Pe,rati°n inC'Ude r69Ular C'eaning °f the lamp and adequate removal <* suspended
not baffecTed *"" S''n°e °r9anisms protected from UV e*P°sure ^ suspended matter
Ozone treatment is a relatively new technology that is finding increasing applications in the
rfTtmHent indUStrV- °Z°ne '°3) iS 8n a"0tr0pic form of ox^en- * is the second mos
powerful ox.d.2,ng agent known and is several times stronger as an oxidizing agent than chlorine
o?± and,?yne' If90'' '" 8 C°°lin9 tOWer' °Z°ne reacts with *e ••a"*: debris and mcrobes
to form ox.dat.on products. The oxidation products formed then react with other microbes, fouled
on wh>H 8 ,Sf 6> Thceoretical|y' ozone contr°'s scale by removing the organic mucinous deposes
o f± aS T' Fuhrtherm°re' the CarbOXy!b 3nd dicarboxylic acids formed from the oxidation
of fatty acids in cell membranes react to form scum and chelated complexes which prevent further
ch±?*t aSS'St '" rem°Vin9 SC8le depOSitS' Corrosion protection is achieved because ozone Hke
'S -H h tO 3 ^ "* 1 °° t0nS °f CO°"n9 tOwer capacitY per hour h co an
• 9 S°me StUd'eS have demonstrated complete, effective treatment of cooling
"T9 °Z°ne a'°ne' the effectiv^ess of ozone in preventing corrosion and scale
!!! ?• m? questfonable- Ozone has' however, exhibited excellent microbiological control in
cooling tower .nvestigations as well as in case studies (Strittmater, et al., 1 993) As wrtn UV
5o±?°o °20nf Pr0baWy d06S "Ot rePreS6nt 3n 6ffeCtive «and-alone coo.ing water treatme t
program. Ozone treatment is costly and is recommended primarily for larger cooling tower
applications typically greater than 500 tons. Thus, although the use of ozone minimizes the
discharge of water treatment chemicals to the environment, the size limitation alone may eliminate
anSmo tmfCrS'derati0n 3t ^ N°rf0lk NAS Si"Ce the Iar9est NAS Coolin9 Bowers are 30* tT units
and most of the units are quite small (less than 100 tons).
4.1.3.5 Option 10. Sidestream Treatment
9°a' °I any C°°'in9 t0wer water treatmer|t Program is to minimize the total
.?* water makeup necessary by operating the tower at the maximum
l*?Tm'' ,6 Pr8CtlCe °f sidestream treatment invo'ves the constant
treatment of a fraction of the recirculatmg water to remove dissolved salts and suspended matter
'"* ** ^ 8Verae CVC'eS °f conc«"tration at four to six cycles for average
3 PHrf0rmed effiCiemlY' sidestream treatment can increase the cycles of
* „ m°re' and may even enable the sVstem to 0Perate with zero bleed or
S dtrP/ deptending on the scalin9 tendencies of the makeup water (Spear and Matson, 1 984).
cost A,r treatmtenl Ca" 5e C°St effeCtiV6' dependi"9 on the fresh makeup water composition and
osnL Altematlve techniques which maV be apP«ed through sidestream treatment are reverse
non ^h !on,exchan9e' softening, electrodialysis, filtration, and centrifuge treatment. As with other
non-chem,cal approaches to cooling tower water treatment, sidestream treatment potentially
m,n,m,zes the addition and subsequent discharge of cooling tower water treatment chernSalis.
f°r SOHdS C0ntr°' is an effective mechanism for controlling suspended
and the resultant microbiological fouling, and may eliminate many problems
4-20
-------
P°SttS '" °Pen recirculatin9 cooling water systems. This technology may be
alone or ,n conjuncfon with other types of treatment, depending on the characters of the
makeup water and the desired operating conditions. Sidestream filters have been used ?o a number
corSn o I H6 rem°Val °f SUSpended solids in C0°«n9 water. A sidestream fi.ter ,s a u£t whiT
nTrTrt V, t'VertS * V,erY Sma" P0rti°n °f the redrculating water, typical.y 1 to 10 percentAlters
ItnnT t n ? r!m°Val; 8nd then r8tUmS * t0 the system' SVstems ™ Bailable which
automatically back-wash for ease of operation. Commonly used media include sand anthracite and
combmat-ons of both. A sidestream centrifuge represents a more recent technological developmem
t opera esm a s.m.lar manner, except that a centrifuge unit replaces the filter for Llfds remov^
While filtration ,s capable of removing light-weight particles from the system water, centrifugal
rS r;r°Ve *, denSf PartiC!eS> These ^ processes can be ^med .Imu^oSwith a
corr b,ned f.ltration/centnfuge device known as a "hurricane filter,- which has operatedI sucL^ullv
to ehmmate clogged strainers and fouled condenser coils at a facility in Washington D cUCCeSSfU"V
S-destream f,ltrat.on and centrifuge separation both represent economical methods to effectively
f?±r;etSUSPend S,°Hf t0 a minimum and t0 C0ntrol deposits from foula"ts. Filte or cenSue
susTndL03"^ C3lCUlated With 8 Simp'e equation that takes into ac'ount existing and des ed
suspended sohds concentrations, and water losses due to system blowdown and evaporattorT
«:™.0 Sidestream solids removal techniques are often recommended in conjunction with additional
scale and con-OSIon treatment applications, as described above. For example, the KDF process
SS? I**? 3 %?'Suspended solids removal to ^ance the effectiveness of the meSic
m^not- f 6am !° 'dS rem°Val SVStemS 8re also "commended for use in conjunct on w?h
magnefc water condrt,oners, primarily for control of suspended solids and bacterial growth
4.1.4 Summary of Options
_ Table 6 provides a summary of the 10 options for cooling tower water treatment discussed
above. Advantages and disadvantages related to each option are presented. 3tment discussed
4.2 ANALYSIS OF FEASIBLE ALTERNATIVES
h*CnH The *eatment f ternatives presented in this section have been selected for further analysis
based on the.r potential applications at the cooling towers operating at the NAS. The selections are
based on a combination of cost effectiveness, size limitations, reliability and ease of hSSSSiton
and concerns over the amount and composition of wastes discharged to the envlonrS Tough
coo,,ng tower blowdown. Four of the options discussed above have been analy2ed"TndIding
(1) conventional chemical treatment, (2) DIAS-AID tower treatment XP-300, (3) KDF process
treatment, and (4) magnetic applications integrated with solids and biofouling control
4-21
-------
1
TAQES AND DISADVANTAGES
|
§
05
0
F
TABLE 6. SUMMARY OF TREATMENT 01
Advantaaa*
aatment Option
f
Disadvantages
•High maintenance demands
•Poor system operation
•Minimal chemical costs
•Minimal discharge of chemicals to environment
§
i
o
-
•Reduced operating lifetime of equipment
to
CO
o
1
0
•Excessive water consumption and associ
•Minimal chemical costs
•Minimal discharge of chemicals to environment
•o
i
m
Continuous
oi
C .-
to o E
To = E
•S c S
•Treatment can be costly in terms of chen
purchased and required testing and mainte
•Chemicals may be limited in discharge sti
!
i
c
•g •
•Fairly reliable method
•Several chemical options available for customiz
c
"S "D
Conventioni
Chemical A
«
"5
0
ts
"f o
! I
S v
•" c
•Limited operating experience on which to
confidence
•Additional Intermittent treatment may be
biological growth
I S
1 1
S s
i S
•Recent product which has demonstrated effecti
•Operates with little or no system bleed
•Cost effective, in terms of chemical usage and
"1
la.
rt XX
DIAS-AkJ T<
Treatment )
if
E
49
n
.£
a
n
•Difficult to maintain adequate control
•Undesirable dissolved solids may accumul
g
s
o
Ji
^
•Minimal chemical costs; sulfuric acid an econon
•Minimal discharge of chemical to environment
1
pH Adjustm
in
•Softened water may be corrosive
•Generally quite expensive
•Provide scale control only
•Minimal chemical costs
•Minimal discharge of chemical to environment
•Produces soft, non-scaling water
•o
c
•
e
Base Exchar
Ion Exchang
Processes
to
.£
— "5 S
c 2 .£
•5 i! E
^— £ c S
> — e >
c -= > o
« -5 Jf S
A ^ ff O O
2 o 5i *" o
jQ COO
•Limited operating experience on which to
confidence
•Additional filter unit necessary for solids r
•May cost slightly more than conventional
•Operating experience shows Inadequate c
growth; dosing with blocide or acid may be
a clean system
a
£
o" "
•Minimal chemical costs
•Minimal discharge of chemical to environment
•Waste product consists of recyclable metallic all
•System is telf-regulating by responding to chan(
IB .
C
§
£
u.
Q
rC
"5
I
S >.
o a
£ I 1
a •§ 2
•Limited operating experience on which to
confidence
•Additional sidestream treatment usually n«
for solids removal
•Additional control may be required for mic
growth
•Minimal chemical costs
•Minimal discharge of chemical to environment
•Lifetime warranty
•Minimizes maintenance demands
•Effective against scale and corrosion
ii
ro Q_
it
CO
B
'c
3
c
'«
o
S1
^B
•Generally quite expensive
•U.V. limited to small size; ozone limited to
•Not effective against scale or corrosion
•Minimal chemical costs
•Minimal discharge of chemical to environment
•Effective Sterilization Techniques
> c
Ozonation, U
Light Treat mi
o>
o
**
^
£ c
e "
C *^
c c
o •-
I 2
•Generally used in conjunction with another
reduce solids and the potential for microbial
sffective stand-aione treatment methodology
a
.§
•2
'o
•Effective treatment for solids removal and contro
•Minimal chemical costs
•Minimal discharae of chemical '"
-------
4.2.1 Base Conditions
Due to the variable nature of activities concerning the NAS cooling towers and difficulty in
obtaining tower-specific operations data (i.e., chemical volume and cost data), a base condition or
set of cond.t.ons has been established to enable the analysis of pollution prevention alternatives
The base condition consists of a hypothetical 100-ton cooling tower with 1,000 gallons of system
water which operates at 4 cycles of concentration with a 10°F temperature drop across the unit
The tower operates at 100 percent capacity for 12 hours per day, 6 months per year. The pump
recircuiation rate is 300 gpm. At these operating conditions, the tower will evaporate water at a
rate of 3 gpm; tower bleed is equal to 1 gpm. The total makeup water requirements for the tower
are 4 gpm, or 86,400 gallons per month. Base conditions for the analysis, including a description of
the cooling tower, the makeup water characteristics, maintenance, and cost assumptions, are
included in Table 7. Water and sewer costs presented in the table and used in the analysis
represent actual rates paid by Naval Base Norfolk to the City of Norfolk public water supply.
Makeup water characteristics are based on information provided by contractors servicing some of
the NAS cooling towers, and from the City of Norfolk Public Water Supply, from the most recent
quarterly grab sample collected at the 37th Street location.
Subsequent to this one-tower description is an extended base condition which assumes that
all 28 cooling towers at the Norfolk NAS operate under similar conditions (e.g.. 4 cycles of
concentration, 10°F temperature drop, 100 percent capacity for 12 hours per day, 6 months per
year). The various tower sizes, as listed in the Master Equipment List, Table 1, have been used to
calculate application rates and treatment costs for the four treatment options analyzed in the
following sections.
Maintenance costs, including maintenance agreements with treatment specialists and costs
implemented by PWC maintenance staff, have not been included as part of the following economic
analysis. All four of the options analyzed would require a regular service contract to ensure that the
towers are receiving adequate water treatment and maintenance. A small degree of variability may
voSo™the l6Vel °f S6rViCe required by the four different treatment options, for example,1 the DIAS
XP-,300 treatment option and the magnetic applications option reportedly minimize system
maintenance demands, and the KDF system is said to require as little as half as many operating
labor hours as a chemical treatment system. However, since these differences are not quantifiable
and are expected to be only slight, they have not been considered as differentiating factors in the
3n3iysis.
Similarly, portions of operating equipment were not included in the analysis because these
pieces of equipment are considered to be necessary for all of the cooling towers, regardless of the
method of treatment applied, and would not contribute differentially to any of the four treatment
options analyzed. The equipment included in this assumption consists of solenoid valves and
conductivity meters used to control tower bleed and blowdown operations.
4.2.2 Summary of Analytical Results
Table 8 includes summaries of annual operating costs and annualized equipment costs for
each of the four treatment options included in the analysis, both for treating a 100-ton tower and
for treating all 28 cooling towers at the Norfolk NAS. The results indicate that the DIAS water
treatment option is the least costly of the four treatment options primarily due to lower water usage
and Jower equipment costs. Conventional chemical treatment is more costly than any of the other
three alternative treatment technologies primarily due to high water consumption and the use of
expensive chemicals. However, the variability among all four options is relatively small while the
vanability among the three alternatives to conventional chemical treatment is smaller.
4-23
-------
Cooling Tower Assumptions* .
Tower Size (ton)
Temperature Difference (°F)
Operating Capacity (%)
Operating Time (months/year)
Hours of Operation/day (hrs/day)
Approximate System Water Volume (gallons)
Makeup Water Characteristics**
Total Hardness (mg/L)
Calcium Hardness (mg/L)
PH
Iron (mg/L)
Chloride (mg/L)
TDS (mg/L)
Water Consumption Rates
GPH Evaporated = size of tower (ton) X 1.8
GPH Bleed = GPH Evaporated/tcycles of concentration - 1)
GPH Makeup = GPH Evaporated + GPH Bleed
Cost Assumptions
Cooling Tower Life Expectancy (years)
Interest Rate (%)
Water and Sewer Cost ($/1,000 gallons)
Equipment Assumption
100
10
100%
6
12
1,000
] °
46
6_f
°'°53
1™
$3
in P|ace f°r tower bleed (solenoid valves and
no capital recovery cost is attributed to the purchase of this
Maintenance Assumption
be equal f°r a" treatment °Ptions< therefore, these costs
Maintenance coste m*y- however, be somewhat lower for
systems because of the reportedly lower maintenance demands of
the
he
Cooling tower assumptions used to generate the costs for all WAS towers are the same
as those used for the 1 00-ton tower.
*! r^f!???0* ^Sed °" jnformation Provided by water treatment specialists and
the City of Norfolk public water supply (37th Street WTP). Prices are based on current
combined water and sewer costs at Naval Base Norfolk.
4-24
-------
oc
1
C/3
fe
8
_i
^
z
CO
Ul
> in
<
H
C
c
H
o
+•*
C
I
1
1
1 *""
OJ
5 c
O i
V ;
o ;
?!-
00 w
< !
z j
— ; <
< H
1^
Q
c w
o «
6 I
(0
o
CO
•CO-
CM
CO
(O
•CO-
CD
in
0
CM
•CO-
s
(O
^
•co-
(O
CM
in
CO
in
r-
S
^.
in
^
V"
O
CM
•CO-
.
5
^
s
CM
•CO-
O
CM
JJ
CO
3
C
CD
.Q.
uT
oc
(
^
t
(O
{
*
in
(0
u
i*^
^
O)
c>
2
05
a
u
tr
•co-
cn
a
£
00
&
o
(O
•co-
in
0)
CM
4^
o
O
"5
c
c
i
4-25
-------
"OBd tha' althou9h <"" DI*S chemical treatment option represents the most
VMment "' Chem'Cal WMtM °enerattd * ««> sv«em ar
numtn, ann"alized costs P«»ented in Tables 8 through 12 have been estimated based on a
number of qualifying assumptions, as outlined in Table 7 and Section 4 2 1 Additional vartohiiitv
s^^T" the four °ptions presented due to th.-rnc^s^irs^
vv,th each treatment technology. While the costs for chemical treatment options
he ann r6 ;°" Ch!?iCa' applicat?on and DIAS-AID Tower Treatment XpWS^SSiv
manlCt° '"r11^ thr°U9h ChemiCa' Purchase*' ^e costs associated with the KDF syitem
Tn ° f aPP|lcat'on technologies consist largely of one-time capital expenditures with
t r« oper in9 costs< capitai expenditures **» **™ ^M ^ PurPoSes of the
thP «n • V '-aST'ng a" apPf°Priate life expectancy for the various pieces of equbment « ince
the ent-re analysis ,s based on a typical cooling tower life expectancy of 20 years the ifT
«« - a maximum of 20 years! Sa^ge va.ue
— - - a
4-2.3 Conventional Chemical Treatment
are su chTf and. co!ts associated with conventional chemical treatment
,«of . ? Chemical application rates and costs are based on the method of
treatment currently applied to the cooling towers at buildings SP367. SP254 and s1?256 The
war =x asassr • •
4-26
-------
TABLE 9. CONVENTIONAL CHEMICAL TREATMENT ANNUAL COSTS
Water Consumption
Cycles of Concentration
GPH Evaporated
GPH Bleed
GPH Makeup
Gallons/yr Consumed
Annual Water Cost
Chemical Usa*
Biocide Use (quart/100 ton/week)
Annual Biocide Consumption (gal)
Biocide Unit Cost ($/gal)
Annual Biocide Cost ($)
Scale/Corrosion Inhibitor Use (quart/100 ton/day)
Annual Scale/Corrosion Inhibitor Consumption (gal)
Scale/Corrosion Inhibitor Unit Cost (3/gal)
Annual Scale/Corrosion Inhibitor Cost ($)
Dispersant Use (gal/1 00 ton/yr)
Annual Dispersant Consumption (gal)
Dispersant Unit Cost (gal)
Annual Dispersant Cost
Equipment
Chemical Feed Pump Unit Cost* *
Chemical Feed Pump Quantity
Life Expectancy of Chemical Feed Pump (years)
Net Present Value - Chemical Feed Pump
Drip Feeder Unit Cost' * •
Drip Feeder Quantity
Life Expectancy of Drip Feeder (years)
Net Present Value - Drip Feeder
7-day Clock Unit Cost
7-day Clock Quantity
Life Expectancy of 7-day Clock (years)
Net Present Value - 7-day Clock
Controller Unit Cost
Controller Quantity
Life Expectancy of Controller (years)
Net Present Value - Controller
Total Annualized Equipment Cost
Annual Conventional Chemical Treatment Cost
100-ton Tower
4
180
60
240
525.600
$1,787
0.5
3.3
$15.0O
$49
1
46
$11.OO
$502
30
30
$13.50
$405
$320
2
10
$887
N/A
N/A
N/A
N/A
$125
1
10
$173
$525
1
10
$727
$210
$2,953
All NAS Towers
4
3,866
1,289
5,154
11,287,260
$38,377
0.5
70
$15.00
$1,O47
1
980
$11.00
$10,780
30
644
$13.50
$8,699
$320
18
10
$7,981
$25
38
10
$1,316
$125
9
10
$1,559
$525
9
10
$6,547
$2,044
$60,948
•Based on chemicals used to treat cooling towers associated with buildings SP367, SP254, and SP256.
. * "Chemical feed pumps are assumed to be used on cooling tower units equal to or larger than 75 tons.
***Drip feeders are assumed to be used on cooling tower units smaller than 75 tons.
4-27
-------
The total annual costs of conventional chemical treatment for the 100-ton tower and for all 28
NAS cooling towers are $2,953 and $60,954, respectively. In addition to costs, the total annual
consumption of biocide, scale and corrosion inhibitor, and dispersant is included in Table 9
Consumption rates for the three types of treatment chemicals when applied to all 28 NAS cooling
towers total 70, 140, and 644 gallons per year, respectively. As described above, this treatment
option would result in the discharge of these total amounts of chemicals to the environment thro'uah
the cooling tower blowdown. . M
4.2.4 DIAS-Aid Tower Treatment XP-300
The annualized application rates and costs associated with DIAS-AID Tower Treatment XP-
300 are summarized in Table 10. Application rates are based on recommended dosage rates
provided by representatives of DIAS, Incorporated. The general application rate recommended for
makeup waters up to 300 ppm hardness is 2 gallons per 100 tons per month; however, based on
conditions of the Norfolk NAS makeup water, specifically 80 ppm hardness, the recommended site-
specific application rate was actually 0.5 gallons per 100 ton per month. A conservative estimate of
1 gallon per 100 ton cooling tower capacity per month was chosen for use in this analysis The
one-time application of an additional 2 gallons of DIAS-AID XP-300 is recommended for each tower
at start-up.
The total chemical consumption rate for DIAS XP-300 treatment of all 28 NAS cooling towers
is 185 gallons per year at an annual cost of $14,606. This represents a substantial savings over the
consumption rates and costs associated with conventional chemical treatment which total
approximately 854 gallons per year at an annual cost of $20,526. Additional savings are realized in
water costs. Since the DIAS treatment technology operates with little or no bleed reductions are
achieved in the addition of makeup water. For the purposes of this analysis, makeup water
requirements have been estimated to account for tower evaporative losses only The actual water
consumption rates may increase slightly with an increased.tower bleed, although representatives of
UIAS, Inc., support the assumption that a zero tower bleed can be achieved with XP-300 treatment
It should be noted, in addition, that the installation of a separate metering system which would
enable separate billing for water and sewer rates at the NAS cooling towers would result in further
savmgs, since sewer charges would be eliminated from the makeup water costs. Norfolk citv water
supply prices are currently $1.34/1000 gallons, while the combined water and sewer orice is
$3.40/1000 gallons.
DIAS-AID Tower Treatment XP-300 represents an attractive option for cooling tower water
treatment. The technology is economically attractive when compared to conventional chemical
treatment, and represents a substantial reduction in the amount of wastes discharged to the
envoronment through cooling tower blowdown. However, although wastes are reduced this option
does generate wastes which are supposedly safe for discharge to the sanitary sewer but whose
composition is uncertain because of the proprietary mixture involved. The MSDS for DIAS-AID
Tower Treatment XP-300 is included as Appendix F.
4-28
-------
TABLE 10. DtAS-AlD TOWER TREATMENT XP-300 ANNUAL COSTS
100-ton Tower
All NAS Towers
Water Consumption
Cycles of Concentration*
GPH Evaporated
GPH Bleed
GPH Makeup
Gallons/yr Consumed
Annual Water Cost
Chemical Use
DIAS Use
Annual DIAS Consumption (gal)
DIAS Unit Cost ($/gal)
Annual DIAS Cost
Equipment
Pump Dispenser Unit Cost
Pump Dispenser Quantity
Life Expectancy of Pump Dispenser***
(years)
Total Annualized Equipment Cost
Annual DIAS Chemical Treatment Cost
N/A
180
N/A
3,866
Negligible-All DIAS users contacted stated that
they operate with zero or minimal bleed off.
180
394,200
$1,340
3,866
8,465,445
$28,783
2 gal at start-up + 1 gal/100 ton/month**
8 185
$79.00 $79.00
$632 $14,606
$61
1
20
$7
$1,979
$61
28
20
$201
$43,589
Cycles of concentration do not apply to the DIAS-Aid system due to zero bleed.
The recommended usage rate for hardness levels up to 300 ppm is 2 gallons/100
ton/month; however, for the relatively soft water (hardness-80 ppm) used at NAS, the
recommended usage rate is 1/2 gallon/100 ton/month. Therefore,
1 gallon/100 ton/month is a conservative estimate.
Pump life expectancy is based on proper pump use (i.e., for DIAS chemicals only). The
use of other materials in this pump may significantly reduce its expected lifetime.
4-29
-------
4.2.5 KDF Process
Annual treatment costs for the KDF process are summarized in Table 1 1 . Since this treatment
technology does not typically include the addition of chemicals, costs consist of annual wa te*
consumpt,on and annualized equipment costs for the KDF media and associated equipment Posts
include the KDF un,t and associated KDF media cartridges. Replacement cartridges coTt $ 8 feach
for ten un.ts and $125 each for a purchase of 26 or more. A prefilter unit for solids removals
me uded in the associated equipment costs presented, although replacement filter cartridges have
not been mcluded m the analysis because the frequency of replacement depends on the Xe-specific
cond,t,ons experienced. Installation costs have been estimated to be zero or minimal sfnceNAS on
s,te personnel should be able to install the new equipment. The equipmem costs Tor thel^DF
system are based on system volume, in gallons of water. Estimated system volumes for the larqer
NAS cooling towers were obtained from Naval Base personnel and are presented hi Tabte 1 System
volumes for the smaller systems were unavailable. The make and model numbers of '
Zl™entatiVely SiZ6d UnltS W6re US6d bV ^DF Personnel to estimate associated system volumes to
determine appropnate equipment requirements. Since essentially all of the system volumes are
estimated and the cost of replacement filters for solids removal has not been included t^eacual
s,2,ng of the KDF systems and their associated costs contain some degree of error
*ThV°tal ChemiCa' consumPtion rate for DIAS XP-300 treatment of all 28 NAS cooling towers
m93J ^ V6![ 3t a" 3nnUal C°St °f $1 4'606' This reP«*ents a substantial savings oe^ the
^'"f, COStS associated wjth Conventional chemical treatment, which total
854 gallons per year at an annual cost of $20,526. Additional savings are realised in
in£the °IAS tfeatment techno'°9V operates with .ittle or no 'bSSuiSSi are
™ , T°n °f mateUP Water' F°r the Purposes of this ana|y**' makeup water
requirements have been estimated to account for tower evaporative losses only. The actual water
D^Tr « ^nT mCreaSe Sli9l?'y With a" '"nCreased tOW6r bleed« althou9h representat^es of
DIAS, inc., support the assumption that a zero tower bleed can be achieved with XP-300 treatment.
AI*H ^ !J°F S^Stem may reduce the consumPtion of makeup water and associated costs
Although the cycles of concentration for operating a system treated with KDF media may be
increased over a system treated with conventional chemicals, the actual ability of KDF treatment to
achieve an increase in cycles of concentration remains unclear. However based on the S^llfv
conditions of the Norfolk NAS cooHng tower makeup water, the toTers a^e ^ted ?o opTraS at 5
cycles of concentration when the KDF treatment system is applied. This represents a It percent
ireatmem" * C°ncentrati°n °ver the °<>eratin9 c*cle* estimated for conventbnafch^micaf
C°StS f°r the KDF treatment Astern are $2,430 for the 100-ton tower and
treatment °f 8" 28 NAS COOHn9 t0wers" As described abov«' *e cosVs are based on
mov8?"1 Vf ""* 3nd d° n0t iOClUde thS C°StS for rePIacement filters used for soHdf
removal; therefore, there is some degree of errof associated with these costs The KDF eauinment
vendor indicated that the capital equipment cost for all 28 NAS towers mW represent an
represent an
ful|-sized
4-30
-------
TABLE 11. KDF TREATMENT ANNUAL COSTS
Water Consumption
Cycles of Concentration
GPH Evaporated
GPH Bleed
GPH Makeup
Gallons/yr Consumed
Annual Water Cost
Chemical Use
None
Equipment"
KDF Equipment Capital Cost**
Life Expectancy of KDF Equipment (years)
Net Present Value-KDF Equipment
KDF Media Cartridge Unit Cost
Quantity of KDF Media Cartridges
Life Expectancy of KDF Media
Cartridge*** (months)
Net Present Value-KDF Media Cartridge
Installation Cost
Total Annualized Equipment Cost
Annual KDF Treatment Cost
5
180
45
225
492,750
$1,675
N/A
$2,759
10
$3,823
$125
2
9
$2,599
$0
$754
$2,430
MM IUMO i owers
5
3,866
966
4,832
10,581,806
$35,978
N/A
$43,062
10
$59,665
$125
30
9
$38,982
$0
$11,587
$47,565
Equipment costs are based on system volume (gallons) as quoted by equipment vendor
The caprtal equipment cost for all NAS towers may be an overestimate because some of the smaller units at
the NAS may not require full size KDF equipment. smaner units at
KDF media cartridge life expectancy varies with the makeup water characteristics. The best/worst case
scenano is a 12/6 month life; therefore, a 9 month life was chosen for this analysis. °eSVWOlSt case
4-31
-------
anL wh£h ™T K y Chemicals and thus produces no wastestream, other than spent meta lie
o?4 1 3 h o1 S ,'f8 T3 SaaP f°r reCyClin9- BaSed on °Perati"9 experience discussed*
9'C OU"n9 Ca" be 8 Pr°b!em with sVstems usi"9 ^e KDF treatment
P,n ,
The at.dV/r ;'hadd?°nal bi°dde maV b6 needed on an occasional ^sis to control fouling
The associated costs of b.ocide treatment, along with the additional wastestreams produced ranno'
Ea'rfSJ? TH- thHUSe °fKbi0dde W°Uld be V9riable and ""Predictable. However Jhepo
attractive both T * qualitative'y Considered to make this treatment alternative ?ess
attractive, both economically and for pollution prevention.
4- 2- 6 Magnetic Applications Integrated with Solids and Bipfouiino Control
chemicu^!L?f !T ,!nd annualized costs for equipment, water consumption, and
chemical use assoc.ated with the proposed magnetic applications technology are presented in Table
Pipe Protect°'s, sidestream centrifuge
towers. Additional savings in instal.ation costs could be realized by con racing PWC
es 0^^620 ^ T^ the incfntallati0n aCt'VJtieS- lnstallation costs for a» 2 NAS cooling
towers total $1 1,620, which represent 80 percent of the total annualized equipment costs.
!S based °n the reported abilitv of *• ma9netic treatment
the °Perating Cycles of Concentration by 25 to 50 percent For the
°n ±r VSIS' " C°nServative estimate of ^ percent has been assumed, which reduces
t0 th°Se associated with conventional
Bromine application at low concentrations (0.25 to 0.5 ppm) by means of a bromine float has
UeS C™™ °f bi°'°9ical foulin9' a|t"ough thfs isTot
Ua"Y 3PPlied °nIV '"" Situations which are Particularly
optlon was '"^^ here to provide an all-encompassing
H C°"SerVatiVe i0 Su^estin9 alternatives to chemicaFtreatment.
have bee" estjmated based on tower size and required dosage
dUS t0 minimum re^uirements for shipment volumes. I? it fs
assocTati ^, nS ', ,?" ?r?*c«on is ""necessary, elimination of the bromine float and
associated equipment would slightly reduce the annualized costs.
for th 7ihnn°.tal annualized costs f°r the proposed magnetic treatment technology option are $2 286
the a^ua,?;2n T J ?*! 51'6°9 fortreatin9 a» 28 NAS towers. As described in Section 42 '?
the ..nnualized costs for the magnetic treatment unit may be slightly inflated bv assumkia a ?n 'vp«r
'" ^ " PW° PerS°n"el may be available for '
4-32
-------
Water Consumption
Cycles of Concentration
GPH Evaporated
GPH Bleed
GPH Makeup
Gallons/yr Consumed
Annual Water Cost
Chemical DM
Annual Bromine Float Consumption*
Bromine Fleet Annual Cost
Equipment
Pipe Protector Unit Cost (Supply & Return Line)
Pipe Protector Quantity (Supply & Return Line)
Life Expectancy of Pipe Protector (years)
Pipe Protector Unit Cost (Makeup Line)
Pipe Protector Quantity (Makeup Line)
Life Expectancy of Pipe Protector (years)
Centrifuge Separator Unit Cost
Centrifuge Separator Quantity
Life Expectancy of Centrifugal Separator (years)
Net Present Value— Centrifuge Separator
Bromine Dispenser Unit Cost
Bromine Dispenser Quantity
Life Expectancy of Bromine Dispenser (years)
Installation Cost
Total Annualized Equipment Cost
Annual Magnetic Treatment Co«t
i wiwii i wwvr
5
1 0 A
1 BO
45
ft tC
225
492,750
$1.675
10
$85
S975
3
20
$375
1
20
$295
1
5
$663
A « »•
515
1
20
$5OO
$526
$2.286
AH WAS Tower*
5 (25% > than normal)
3,866
966
4,832
10,581,806
$35,978
156 Ib
$1,184
$975
84
20
$375
28
20
$295
28
5
$18,551
$15
28
20
$11,620
$14,446
$51.608
•Bromine float may or may not be necessary for control of biological fouling.
4-33
-------
The annuahzed costs for treatment by magnetic applications technology are largely
comparable to the KDF treatment system. Costs for treating the 100-ton tower are slightly lower
for the magnetic systems, while the KDF system is more economical when treating all 28 NAS
cooling towers. This variability is due largely to volume discounts applied to the KDF system
equipment prices. Due to the estimating techniques used to develop costs for each of the
technologies, and the questionable nature of installation costs and additional biocide requirements
the difference in costs between the magnetic system and the KDF technology is negligible The '
magnetic system costs are 20 to 30 percent lower than the costs for conventional chemical
treatment and 15 to 18 percent higher than the costs associated with the DIAS-AID chemical
treatment program.
As with the KDF system, the magnetic treatment application represents a slightly more
expensive treatment option than the DIAS chemical option but may be more attractive for pollution
prevention because of the reduction in wastes generated by this process. The proposed treatment
system, including the bromine float, would discharge approximately 10 pounds per year of bromine
into the 100-ton cooling tower water, or 150 pounds per year into all 28 NAS cooling towers
These bromine wastes may potentially be eliminated depending on site-specific conditions
experienced at the Naval Base Norfolk.
4.3 RECOMMENDATIONS FOR FURTHER RESEARCH
Based on the research performed as part of this PPOA, and based on the results of the
analysis presented above, further investigation is recommended. The treatment technologies
descnbed in Section 4.2 all represent potential alternatives to conventional chemical treatment All
t^rn^nt0"5',-"0!^1"119 th* DIAS'AID Tower Treatment XP-300, the KDF process, and the magnetic
treatment application combined with integrated technologies, are attractive economically as well as
lor pollution prevention. Recommendations for further research include site visits to facilities which
employ each of these three types of treatment technologies in order to gather operating data and to
observe the systems in operation. Additional information gained through site visits would be used
to select an appropriate technology option to be used in a demonstration project designed to
evaluate the potential for effectively treating the NAS cooling tower water systems
4-34
-------
SECTION 5
REFERENCES
American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. "Corrosion and
water treatment," Handbook of Systems. Vol. 36, No. 12. 1973.
Echols, Joseph and Sherman T. Mayne. "Cooling tower management using ozone instead of
multichemicals,"/lS#/?,4£v/ot//na/. 34-38. June 1990.
Encyclopedia of Chemical Technology. Water (Industrial Treatment). Vol. 24:377-384. 1984.
Environmental Protection Agency (EPA). "Prohibition of Hexavalent Chromium Chemicals in Comfort
Cooling Towers; Final Rule." Federal Register, Vol. 40, No. 749. January 3, 1990.
Gurney, J.D., and I.A. Cotter. Cooling Towers. Maclaren & Sons, LTD. London. 1966.
Hey, G.W., and W.R. Hollingshad. Corrosion Control in Cooling Tower Systems: Inhibition Theory
and Practical Applications. NT-87-09-1. 1987.
Meitz, Amanda K. "Cooling tower water treatment in the 1990s," ASHRAE Journal. 28-32. June
1990.
Richardson, Denise S. "Cooling-water System Biofouling," Chemical Engineering. Vol. 89 (25)-103-
104. December 13, 1982.
Spear, K.F., and J.V. Matson. "Enhance Cooling-Water Reuse with Sidestream Softening," Power.
VOI. I 4uO 11 ^.JIot}"**rO. I 984.
Stenger, Larry and Thomas Dobbs. Reduction and/or Elimination of Cooling Tower Treatment
Chemicals. Proceedings of the Watertech Expo '93 conducted by Industrial Water Treatment
Magazine. 56-68. 1993.
Strittmatter, R.J., B. Yang, and D.A. Johnson. "Comprehensive Investigation on the Application of
Ozone in Cooling Water Systems; Correlation of Bench-Top, Pilot Scale and Field Application Data "
Ozone: Science and Engineering. Vol. 15 (1):47-80. 1993.
Tvedt, T.J., Jr., and D.A. Wilson. Effect of Chlorination on Phosphonates used for Scale Inhibition
in Cooling Water. Proceedings of the Corrosion 85 Technical Symposia. Boston, MA. March 25-
29, 1985.
5-1
-------
SECTION 6
BIBLIOGRAPHY
AAc P" 8nd PaUl N> Cheremis'n°ff- Cooling Towers, Selection, Design and
Ann Arbor Sc.ence Publishers, Inc. Ann Arbor, Michigan. 1981.
Encyclopedia of Chemical Technology. Dispersants. Vol. 7:842-846. 1979.
Encyclopedia of Chemical Technology. Corrosion and Corrosion Inhibitors. Vol. 7:1 35-1 38. 1 979.
National Association of Corrosion Engineers. Cooling Water Treatment Manual. 1971 .
6-1
-------
APPENDIX A
PPOA WORKSHEETS
A-1
-------
Rrm Naval Baaa Norfolk
Norton;. Viroiniii
D«t« Jung 20-22. 1894
Prattte. 0164S-0111-00008
Bowman
Chsdud By [> Waters
at 1
WOftKfXfET
1
ASBE8
WTO*
L_
—
EcUblish tha Pollution Pr»v«nooo Program
Extcuttv* L*vtl Decision
Potcy Satcnwm
Corutnjus Buklng
t
Otgano* Program
Name Task Fore*
Suit Goals
t
Compt*l» Pnliminary Attturmnt
CollKtOaa
R*vwwS
-------
Bna Naval Base Norfolk
8Hr Norfolk. Viroma
Ott» JufK 20-22. 1994
PretMo. 01645-0111-00008
Bv Bowman
Checked 8y__D§Waters
o« 1
woflKSHirr
Bnn: U.S. N«vy
n«it Naval B&sa Norfolk
Oajmtmanfc Naval Air Station
Anc
Oty:
Norfolk. VA
: (205) 639-6451
Major Products:
EPA Generator Mumter:
M^orUnft
Product of Service:
rtr. Management support, and maintenance of facilities, equipment, and personnel
employed in U.S. Naval operation*
Facfflt>
-------
Ptan Norfolk Base Norfolk
Site Norfolk. Vfrrinia
Data Jur* 20-22. 1994
WORKSHEET
3
PoOution Prevention
Assessment Wortaheets
Prat. No. 10645-0111-00008
PROCESS mFORttATOM
B«w*tA«^M4
rivpitfwa
Checked!
Sheet 1
Bv Bowman
}y DeWaien;
of 2 Peot (91
Process Unii/Opereflon: CHEMICALLY TREATED COOUNG TOWERS (SP367. SP254. SP256. V53. SP29.
V16.SP45.SPei)
Operation Type: Ocentfmieus (8 Discrete
Q Batch or Sami-Sateh D Other
Document
Process flew Oiegram
MaterisVEnergy Salanea
Design
Operating,
flowMnount Itessumnfftts
Stratm w«t«r flew
Anatys«c/AsMy«
Strt«n witar ouatttv
^fOCMS DiSCrtptfOM
Opcntag Manuals
Equipment Urt
Equ^nwnl Spsdfleatfon*
Piping and tawtmrnmi Oiasnms
PJot and Evaluation Plants)
Work Ftow Otegnms
Hazardous Wasta Msnifssts
eaWarien tovtnUxiM
AnmnVBtmnlai Reports
Environmental AutSt Reports
PsnrtWennlJ AppUe»Uens
Batch SheeKs)
Materials AppfieaOons Diagrams
Product Composition Sheets
Material Safety Data Sheeta
Production Schedules
Stabs
Comj>4««e?
(WN)
Y
Y
Y
N
.Y
Y
N
Y
Y
N
N
N
N
N
N
N
Y
N
N
N
Y
N
V
Currant?
OWN)
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Ust
•fc *-t
nw*v*9R
U**dbithis
Re|Mrt(Y/N)
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Document
Number
Lointion
A-4
-------
firm Norfolk pa^« Norfolk p
SHt Norfolk. Viratnia
tett Jim 20-22. 1994
WOftKSHOT
3
U48.VS3
AM
Praf.Me
fetation Prevention *t*psrtd
tassmtfit Worksheets
Checked
i. 10645-01 11-OOOpa Sheet_l.
PROCESS BffORMATWH
Bv Bowman
Bv DeWatens
°*.,?.., p"«« «
TiD COOUNQ TOWERS (IP13, LP2. LP3. U»«. S33. SP2M. SP64. T26.
•)
Operation typs: Dcentteuewt (£ Discrete
D Bate* or SaraJ-Bateh D Other
Document
Process Row Diagram
M«£trla»Kner9y Balance
Dttign
Operating
Street*
Proem Description
Operating Manuals
fduipmtfit List
«P«n« wd IftctruiMnt Olagrwm
Wet and IvahMtiofl PtM««)
Wort How Diagram*
Hazardous W««t« Mantftsts
Enviiwwwntat Auttt Rwerts
^nnWPwmtt AeeMeatieM
Batch Shacks)
UatMWs AppOeateiw Olnnms
Predacl Compe««on Sheets
Material Safety Data ShMts
Status
CompJeta
(Y/N)
V
Y
V
N
N
Y
N
Y
Y
N
N
N
N
N
N
N
Y
N
N
N
N
N
N
Y
Cumnft
(Y/N)
Y
Y
Y
Y
Y
Y
Y
Y
Last
Revision
Ifeedbttftis
Report (Y/N)
Y
Y
Y
Y
Y
Ooeumem
y
•• i
H
A-5
-------
nnn Naval Bass Norfolk
Stte Norfolk. Virginia
Dct* June 20-22. 1894
WORKSHEET
4
•toNution pnMMtton
Pro^No. 01645-0111-000
rTepsred 8
Ch«ek>dfr
39 ShMt 1 o
0»VT MATCRIALS SMOURY
8CC SIC11ON 1. TABUE 2
Attribute
Name/ID
Source/Supplier
Annual Consumption Rate
Ov*ni
Components) of Concern
Pwchaaa Priea. S oef
OvefaN Annual Coot
Delivery Mode1
Shipping Container Sbattypa*
Transtar Modt4
Cmpty Conttirwr Oispecal Uan^snwnt*
Shelf Uta
Supptttf Would
• accept snipping conuuMfu (T
-------
Finn Naval Base Norfolk Poflwtton Prevention
' • A*»
Sita Norfolk, Viroinia
Data jun» 20-2^. 1994 , , Pmjj m
Prtowtd By Bowman
nanwm wa««ahMta
OMCkMll
01645-0111-00008 »»•* 1
. WORKSHEET PRODUCT SUtlUARY
9 NO PflOOUCTSreOM OPERATION
Attributt
NamertO
eempeAeflVAttributt of Conewn
Annua) Consumption Ret*
Owna
CempeMnt(«) of Concern
Annual RCVMMMS, 8
•
„ . ._. ..-j-
Shipptag Containtr Sin A typ*
Oratt* Storag* Uod>
ShtHLH*
Rtwofk Pou&to (Y/N)
CtntoiMrWouW
• rttcz «p«cme«tion
-------
Rim Naval Bas» Norfolk
Site Norfoflc. Vtrotni*
Date Jun« 20-22. 1994
WORKSHEET
PeButton Prevention
Asaaasment Woricsheet
PreLNa. 01 642-01 11 -OOP
WAST
i
Checkedl
08 Sheet 1
1 CTftCAM SUiniAffY
O-JEfcUCALLY TREATED COOUNS TOWERS
Attribute
Waste KVNanw:
Source/Origin
Component or Property of Concern
J
Ovani
Components) of Concern
Cost of Disposal
Untt Cost (S pen >
Overan(paryaar)
Method of Management1
JftoQUasttOty GovRp4i«viCj9
Treatment/Disposal Cost
Potential UabOtty
Waste Ouanttty Generated
Waste Hazard
Safety Hazard
MWwtaHen Potential
Potential to Remove Bottleneck
Potential Byproduct Recovery
Wt(W)
Sun of Priority Rating Scores
Priority Rank
By Bowman
ly 0«Wat§rs
OMCfiption
Stream Mo.
Bieed mater
Chemcai addiUon
See Tables
34^
1 Inlninnai
WIKIaUWfi
Bieode
NA
NA
POTW/NPOES
N
(R) RxW
£(RxW)
Stream No,
•MMMMBM^M«5SS£
Bleed water
Chemical addition
See Table 2
607.6
Unknown
Scale/Corrosion
toasters
POTW/NPOES
N
Stream No.
Bleed water
Chemical addition
See Table 2
1444
Unknown
Dupersant/Antifouim;
POTW/NPOEJ5
N
Rating Rating
(R) RxW (R) RxW
•
r(RxW) Z(RxW)
NOUS: T For ezainpie, aartitefy lanem nazardoue waste tendfM. on^ta recycle, incineration.
combustion with heat racomwy, actuation, dewaiarlni), *«c.
«^ Rate eeeh stream to each cstegory on a scale from 0 (none) to 10 (high).
A-8
-------
Firm Nival Base Norfolk
SRe Norfolk, Viromia
Date June 20-22. 1894
WORKSHEET
6
Pi
eOuUon Prevention
Anteatment Worksheet
Pro}. No. 01642-0111-000
WASTE STREAM
Prepared!
*
Of^ Sheet_2_<
SUMMARY
iy Bowirvsn
Iv DeWaters
>* 3 P«9« of
CHEMICALLY TREATED COOLING TOWERS
Attribute
Waste IttName:
Soureanrigm
Compoiient or Property of Concern
Annual Generation Rate (unto csiSenc l
Overel
Components) of Concern
Cost of Disposal
Unit Coat (S oen )
Overafl (per year)
Method of Management1
Contains** Returnable (Y/N)
TreatmemVOispesal Cost
Potential Liability
Waste Heard
Potential to Remove Botteneek
Wl(W)
Priority Rank
Oeeeriptien
Stream No,
Bleed water
Chemical «*SSoo
See Table 2
28.1
Unknown
Nonabd descaier
POTW/NPOES
N
Rating
(R)
L(RxW)
RiW
StfUSRI No.
Rating
TO
L(RxW)
RiW
j
|
Rating j
L(RxW)
woe wane ttncSflH, on-eite recycle, incineration.
>. Rate each stream In each ea^agoiy on • aeaie from 0 (none) to 10 (nigh).
A-9
-------
Firm Naval Base Norfolk
SHa Norfotk. VTrdnla
Data June 20-22. 1894
WORKSHEET
A
^
oOutten PravantkM
Aaaaasmsnt Workthaal
Prej No. 01642-0111-000
Praparadl
a
ChaetodB
08 Shaat_2_<
UNTREATED OXXma TOWERS
ASrfUrte
Wostanmama:
SoureaOrlgm
CemponMit or Property of Ceneom
Annual OanaraUon Rata (unto )
Ovaral
Components) of Concam
Coat of Disposal
Unit Coat (S pan >
Ovaral (par year)
Method of Managamant'
Containera Returnable (Y/N)
Priority Rating Criteria1
Regulatory CompUwce
Treatment/Disposal Coat
Petantlat Uabfltty
Waatartezard
SafatyHazard
UinlHUUtMfA POtAAtW
PetantM to R«mova BeWanaek
Potential By-product Raeovary
Wt (W)
S»m» of Mortty Rating Score*
Priority Rank
ly Bowman
IY DeWatent
Daacription
Straaratto. NA
Btaadwatar
CnamfcaladtSSon
8aaTabla2
Unknown
BtocxJt*
NA
POTW/NPOeS
N
Rating
(R) Rx W
L(RxW)
Stream No.
9
Rating
(R) RxW
L^RxW)
Stream No.
Rating
(R) RxW
Z(RxW)
Notaa: 1. For axampia, aanitary landfM, nazardeua waata tewflm, on-cMa laeyeia, mebwration.
S. RataeKhatrnmn«aehcatas^enaacalafromO(rtc4M)ta10(high). -
A-10
-------
Rrra Naval Best Norfpfl< Potation feMMton PnpmdBy Bowman
Assessment WorfcsfcMtt
8«« Norfolk, Viroini* Checked Bv DeWaters
tte» ^»nf gfrgS, 19^4 — PretKo. 01645-0111-00008 »»•< 1 of, 1... P«v* erf
WOflK»«rr CATION GENERATION
^7 " " " ------
w«vui9|| rirucjpaniB I.MUI DOWTTWI. «ian L/flWAior
eJmSqut) Bramstorming
s. Sam Heaney. Scott Snow
SEE ATTACHED
*
fUtioiute/Rtmarkx on Option
-------
NAVAL BASE NORFOLK
NORFOLK, VDGINIA
PPOA BRAtNSTORMWG SESSION
COOUNQ TOWER OPERATIONS
OPPORTUNITIES TO REDUCE WASTE GENERATION
INPUT MATERIALS
SHl5LyWhal apptar to ** can***®* tor altertflonrf current practices to reduce
input materials .
* aSffnathri gystena
Reduce consumption rates where feisfeie
** ** "^ ««eed what win be required
B. WASTE MANAGEMENT
Reduce waste water volumes from coofing towers where
*ewer system, not
a contractor tor the base may perform this task In the near
***** material8 whtre l3088*^ <•*. containers (or chemicals used m
AWARENESS
Communlcale environmental Information and objectives to enpteyees
Periodic friendly- Inspections of areas to assess enwonmental status
Ensure employees understand environmental impacts of all processes and materials
SSeS*^^111111^
INVESTIGATION BY PROCESS
CURRENT COOLING TOWER OPERATIONS
and ernptoyjn° •eali' COTOSion'
A-12
-------
system (/.«, sanitary
« contractor tor the base may perfofm
B. ALTERNATIVE COOLING TOWER OPERATIONS
"* th°dt ^ C0°an9 tower OP®1300"8- ""» m^no* identified were
(1) Notr«atment
(2) Continuous b(ee<^off or blow down
8 g^I*?^ch«nlctJ«caiUc^pr^^
(4) WAS-Aid Tower Trwttmtnt XP-300
(5) tflaojustment
ISLS* «wtenoe »*d ton «xchanoe processes
process
(f) Magnetic applications
(Jl Ozonatfen or ultraviolet treatment
(101 Stiestresm treatment
Assess feas&Bty of four selected processes:
i ^^r^sssa
(3) iGDF Process
(4) Magnetic appBcations
R*»mrntnd processts tor demonstration at the Naval Base Norfok
A-13
-------
Firm Naval Basa Norfolk
8ttt Norfoik. Virginia •
•
Date June 20-22. 1994
PoOutten PrwMttkMi
Asa««aiMnt Wwtehtets
Ptd Mo. 01645-0111^)0008
PraparadBy Bowman
Cbackad Bv DeWatens
10 Pas«__of,
WORKSHEET
8
OPTION DESCRIPTION
COOUNG TOWER MANAGEMENT OPTIONS
NMM Contimjou« Wwdoff or btewdovw
Briefly
-------
Naval Base Norfolk
Norfolk. Virginia
D«tt June 20-22. 1994
PtolNo. 01645-0111-00008
BY Bowman
OMCtodBy DeWaters
Short 3 or 10 P»g«__eif.
WORKSHEET
8
OPTION DESCRIPTION
COOLING TOWS* MANAGEMENT OPTIONS
Britfty desert* mtoptton; Addition of bioeictea. seal*, and corrosion inhibitors.
and dispetsants/antrlouiants. This reduces water oonstimption and protects the cooling
unrta. but tncrgascs chemical consumption and waste generation.
w««t» strt«n(«) Aitacted; Cooling towar discharge
input MaterttKi) Afteetcd: Chemical treatments fisted above.
Produces) Altetod: MA
Indicrt* Typr.
I Seurea Reduction
__ Equ^nwnt-flciatcd Chengt
X Pc»»on»»VProc8dur»-nftet«d Ctumgt
_X_
Orate
IMwtel rauMd for erigiiMl pufpeM
itattftt ua«d for • imrar^tMltty purport
Originally pfopo««i by; TRC
TRC
Octe «304tfit2«4
Apprevrt tor study?
no By: TRC
Pottntitl option for cooing water traafiMttt
A-15
-------
Ptoro Naval Base Norfolk
8tt» Norfolk. Virginia
DfSm June 20-22. 1994
Praventtoh
AsswsiMnt Worksheets
Pfrt.Ho. 01645-0111-00008
Prsp«r»dBy Bowman
Chectod By DeWatt-rs
8h««t 4 of 10
WORKSHCET
8
OFTKJtl OCSCRtmON
COOUNQ TOWER MANAGEMENT OPTIONS
Option Item DIAS-Aid Toww TrMtmant XP-300
Briefly
tt*eptton; A chwnfcari treatment that a purported to aBow no bleed
from smafl coofing towara and minanal bleed from terger ones and uses tow application
rates.
w«t« sa»»n(«) Aftectxfc Ceofing towtr ctocharge water
input
Chemical treatments Bsted above.
NA
Indicate Typr. CD Soure* Reduction
Ctwng*
Chang*
__ On«tt« Material rtuoid for original purpose
Oftaite — ^ ^^
TRC
•204O2/M
TRC
tete:
AppfevBdfarttudy? X yos
rao By: TRC
B**a«wteAeetptaaeaorBaiactJon P««tflal cotton for emfogmtcrtmdnwnt
A-16 .
-------
Rnn Naval Basa Norfolk
Site Norfolk. Virginia
Pete June 20-22. 1994
Pollution
Assaeement Worfceheete
PrelNg. 01645-0111-00008
Prepared By Bowman
Checked Bv DeWalers
Sheet 1 of 10 Page__of.
WORKSHEET
8
OPTION DESCRIPTION
COOLING TOWER MANAGEMENT OPTIONS
Option NMM No treatment
: Unite am not traatad for scaJa or corrosion, although they
may receive a Mocatte. Unto art cleaned with brushes in tne off-season.
WMt»str»«m(«)An»st«d; CooUng tower discharge water.
nput tutKi«m) Afl^ct^ Chemical treatments - scale and corrosion inhibitors, biocides. and
dispersants/antifouiants.
P*ochict(«)
NA
bidieat* Typ«: QQ Source Reduction
_X_ Equipnwnt-Aeiated Cheng*
X PtraonneVPreeeduf»-Releted Cheng*
_X_ Materieic^eieteel Cheng*
O Reeyeiing/ReuM
Onett*
Materiel raueed for originel purpoee
__ MeterielMedferatoweixiuelltysufpoM
HeterieleoM
Origteeny pfoposed by TRC
Octet
THC
Date: 0ao-Kt2/94
Approved for etudy? X yee no By: TRC
•aeon for Aeeeptenee or Rejection Petenaal option for eoefing weter treaiment
A-17
-------
Ron Naval Bate Norfolk
SHe Norfolk. Virginia
Data June 20-22.1994
Pofiution Prevention
Asaeecment Workaheeis
ProLMo. 01645-0111-00008
PraaaradBv Bowman
Cheated Bv DeWaters
Shert 5Tof 10 ***«•_<
WORKSHEET
8
OPTION DESCRIPTION
MANAGEMENT OPTIONS
Option Kama pH Adjustment
Briefly deacf&e the epaon; By managing pH teveb. tcate-forming rronerais can be
kept in solution «s salts and compsMty can be kept In check. Incraased ackfity can damage
equipment Requires high JeveJ of monitoring. May require corrosion inhibitors as well.
w«»t« Str»«n(i) Afltcted: Goofing tower discharge water.
input itot«rtaK«) Aff>et»d; Acid added to cooling water andpossible corrosion inhibitors.
Product(«) Affsct»d: NA
Indlort* Typr. IS Source Rwtectk
Rffiiatad Ctenge
VPrecedure-fteiated Change
X Pars
X M«tetfsi»4)etatod Change
O Recycling/Reuse
__ Onsfte
OfWte
____ Material rauMd tar original pwpose
___ Matarttl used tef a towcr-quaBty purpo**
UsterieleoU
Originally propesad by: TRC
Date: */20-6O2»4
Revienwdby TRC
Data: «20«22/94
Approvad for atudy?
ne By: TRC
Reason for Aeeepianee or ReJeeUon
option for eoofing water traatmant
A-18
-------
Pbm Naval Basa Ngrfpflc
Sttt Norfolk. Virginia
Date June 20-22.1994
Pollution Prevention
Assessment Worten**te
Pre|.Na. 01645-0111-00008
Prepared By Bowman
Chackad By DeWatere
Sh*at 6 of 10 Paot__of.
WORKSHEET
8
OPTION DESCRIPTION
COOUNQ TOWER MANAGEMENT OPTIONS
Option NM» ZeoSte or base exchange and ion exhange process
Briefly dascrib* tt» option: A water softening process in which harmful water constituents are
removed and replaced by toss haimful materials. May increase corrosivity.
W««t« Stre«m<«) Afftetod; Coofing tower cfischafga water
input tet«ri«i
-------
Rrm Naval Base Norfolk
Etta Norfolk. Virginia
Date Jung 20-22.1994
PoJfartten Pnwwtilon
AaMwnant Wocteahaata
PreLMa. 01645-0111.00008
Pfacarad By Bowman
Chaekad BY DeWaters
7 of 10 Pas«__
-------
Firm Naval Base Norfolk
Site Norfolk. Virginia
Data June 20-22.1994
Pollution PtatranUun
Aeaaesmant Worfcxheats
PrelNo, 01645-0111-QQQQS
Pfaparad By Bowman
Cnackad Bv DeWaters
Shaat 8 of 10 Page of
WORKSHEET
8
OPTION DESCRIPTION
COOUNO TOWER MANAGEMENT OPTIONS
Option Kama Magnetic Applications
Briafly describe tn» epflon: The units provide permanent protection against scale
and corrosion. They force minerals into solution by generating an electric field in the cooling
water, thereby changing Its potential. This electric charge protects against scate buildup and
^ ; - ~~ W r ™ ™ "^ ^f^mmmw *vr* *r*^«*)«^ **%l«t^WW IBI •
corrosion, but is not proven •ffectiva against biotogical agents. Sidestream centrifuge units
and optional bromine float are installed for control of biotogieal fouling.
Wa«t« str«am<«) Aftact«fc Coding tower discharge water
input M«uriai(«) Affected: Magnetic systems attached to piping on units. Possible chemicals
biocidss) added to cooling water.
Produces) Affaetad: MA
Indicate Typa: IS Sourea Reduction
X Eautomant-flatrtad Chane*
X PanonnaVPreeadura-RaiatadChanga
X Ustariaia-Ra4atad Changa
O Raeyding/Ri
' Onatta
Offaita
___. UateriaJntuaad for original purpose
_ Mctariaiusadforalowar^qtMlitypurpoaa
Itetarial aoM
Originaay prapoaad by; TRC
Data: 6VS&4/S2/94
•viewed by TRC
Data: 6T20-W22W4
Appiowd for atudy? X yas
ne By: TRC
•MonforAccaptancaorRaj^tkw Potanteloptionforeoofing watartreaimant
A-21
-------
Firm Naval Base Norfolk
Site Norfolk. Virginia
Date Jung 20-22. 1994
Pogutfam Prevonllon
A*3ee*ment Worksheets
ProlNo. 01645-0111-00008
Piepared By Bowman
Checked Bv DeWaters
Sheet 9 of 10 PaS> of
WORKSHEET
8
OPTION DESCfttPTiON
COOUNQ TOWER MANAGEMENT OPTIONS
Option HMO* Alternative sterffization technique (ozone, ultraviolet Bght)
Briefly osserfeetf»opaoiE Using ozone Of idtravfeUt Bght. cooling water is treated to kHi
bjotoojcal agents. Both may not •ffectivaiy control seal* or corrosion, and their applications
appear limited.
WMU strmn(») Afftctod; Coding tower discharge water
input Utt»rt«j<«) Affsetad: uitravioiet or ozone treatrnent systems
Produet{») Affacted: MA
lndlc«t» Type: 03 Source Reduction
X EquipRMnt-RvtBttd Chang*
X P*raomt*i/1Preeadurt^«tat*d Change
X Uatwisia^Mttod Change
O ReeyeSng/Reuse
__ Onstte
Oftatte
__ Material reused for original purpose
___ Material used for • lower-quality purpoae
Material eoM
Originally proposed by: TRC
900*020*
Reviewodby.TRC
Date: 6/20-6/22AM
Approved for etudy? X yec
no By: TRC
Reaaon for Acceptance or Rejectton PotentW option for cooing water treatment
A-22
-------
Rm Naval Baaa Norftpdt
Ste Norfolk. Virginia
Date Jun« 20-22. 1994
PeOuUon Prevention
AsMttiMnt WoriohMts
Prej. Ho. 01645-0111.00008
Bowman
Cl»ck»d Bv
Sh««t.1p_oMp_ Pag,__ of __
COOUNQ TOWEB MAHAOEMENT OPTIONS
Option MM» Sktestrearn treatment
By averting g portion of the coofing water from the system
andcor>staf%treaJnflit.bieedcantedmst^ Sev^,
processes can be applied to the tktestrMm. hdudno reverse osmosa. ion
softening, etectnxflalysis. fltoation, and centrffuge treatment These techniques are normali
used in conjunction with another treatment technotegy.
w«»ta str»«m(«) Affaetad; Cooling tower tfscharoe water
input Uat«mKt) Afteetxfc Tfaatmant •qutement and
lndieat«Typ« B! Some* ftetactton
OriginattyprepoMdby; TRC
TRC
R*ctJon PoteMtel option for cooing w** twttn,^
A-23
-------
NavaJ Bas« Norfolk
saa Noffoflc Virginia
Data Jung 20-22. 1894
•TO}. Me. 01645-0111-00008
»taparsd 8y__Jgkjwman_
Chacfcad By
UL P*9»__«*__
WORWHOFT
9
PROflTASJUTY
CONVENTIONAL CHEMICAL COSTS - 100 TON TOWER'
Capital Cocts
•wchaaad Equtpnwtt $2,560
USfflCy CemacUona
SUrt-up and Training,
Othar Capital Ce
Total Capital Coals $2.580
hcrsmantal Amttori Opi
Chattflt in Dtipoaal Coats
Changt In Raw Material Coats M7*
Chanoa hi Ottar Costs
Annual Mat Opafstteg Cart Savings $-47
Payback Parted (la ycaro) »
Tatat Capital Coats
Annual Net Operating Cost Savings
1 Coos an compared to no treatmant
•n* coat la btflv^J by subtracting annual easts far convention* ehamieaJ tmamMm frem aryiual costs for no
traaimtm. Annual COBS tor tmatmant can to found to Tabta 8. No Iraamant costs an danvad by assuming tha
tmwopafataaatacydasofconcafantion.- Wtttt and sawar costs an $0.0034 par oxflon of watar consuiilwd.
wsft an annual cowmpaon of 784.400 gasoitt. An annual t*xtta coat of $1S to addad. assuming 1 gallon erf
bixidafcueadamualyatSISparsaOan. INs Wak S2.O6 amuaty tor no tnaanant
» Sines tha inaanw^ anr^ opara«ng cocls for cr»niicsl Irwimart a» highar than for no traatmart. dua to
ehamfcal costs. fl»a payback psiM camot ba cafcuMsd for Ma option. Eeooomic analysis of chamical
trwcnant wsua no tnatmant is not a wmpte issua. aine* Oura an many MMan costs ascociatad with noiv.
------ .—• ——-.».« »* ..w. • «.^«v iHWM«t a^M»v www «BW many fBQlJVn COW •KOCSB19O Wlwi nOO1*
which ctnfiol ba qtantiCwl An untraated towar return a high dagraa o« maintananca and satvica
Jl? *!!!^ d°99^ ^''^ "^ a*aa<^
th» oMrtf Katbna of tha unit is Bcaiy to ba leas ttan 20 ya«s. raKAhg in incmasad capital damands incutr»d by
Intpwchasaefanawaystam. —^— jr
A-24
-------
PUS CHEMJCALTREATMENT. 100 TOM Tftwca
Ctiangt in Ottm Co«t«
•••——i—___
*»««* N« Qp«nrttefl Co«t Savings $724
PaytaekPwiedOnyMra) . Trt»l CipBal Cottt
A«x»I Ntt Opmtfatg CMt Saving
"8ffl
A-25
-------
Naval Baaa Norfolk
Site Norfolk. Virginia
Data Juna 20-22. 1994
Pofcitfon Pra»nntloii
Prol No. 01645-0111-00008
By Bowman
Chacfcsd Bv DaWatera
WORKSHEET
9
PflOnTABUTY
KDFTREATMENT. 100 TON TOWER1
Capttri Coasa
Pure*
l $5.518
Uautriat*
ConncdloMa
«act-yp aad Training
OttMr Capital Ca«8
Total Capital Corta $5318
i)«Cc
Chanja la Dtepcaal Coata
Chanea hi Raw Malarial Ceata $€88*
OtangalROtharCaata
$688
Payback Parted (ta yaara)
Tetat Capital Ceatt
Awiual M«t Operating Coat Savinga
10*
1 Costs ara comparad to no treatment
This cost is derived by subtracting annual costs tor KDF treatment from annual costs for no treatment Annual
eoetstotieatiiieM can be found in Table 10. No treatment coata ara derived by assuming the tower operatts at
2 cycles of concentration. Water and sewar eoats ara $0.0034 per ,aon of «^ consumed. «fln an arawi
TnpUon of 788,400 gafane. An annual bfctide cost of SIS is added, assuming 1 gaton of txsobt is u>ad
*E«incw ttrm: a*Moi^ bk^^ i«J i^ ehsniicsls
A-26
-------
Rm> Nava)
Norfolk
8»a Norfolk. Virginia
Daia Jun« 20-22. 1894
Aaiaaamanl Woriohaata
PrBi.Ho. 01645-0111-00008
Bowman
Chactod By DeWaters
Shaat 4 of 4 Pa9a__.rt.
won
UAQNCTC TREATMENT -100 TON TOWEfi'
PwrttaMd Equipment $4.495
$500
Tent Opttai COMS $4.995
tncn
iital Aroxtal Oft
Dt»po«al Cc«t«
CtwngcinftewltettttaiCaati $936*
OtlMr Cecta
$936*
P^tack Parted (hi ywm)
Total Capital Coata
Amus* Nat Opantfng Coat Svttogt
' Com am compared to no tnjatmant.
* This coat to darivad by aiAuacUng annual coata tor magnate ftaatmant from annual casts for no traatmeftt.
Annual COM for traatmant can tw found taTabla 11. No traamant costs ara darivad by auumng tha towar
op«f»«t at 2 eydaa rt coneafmaSoa Wa» and aawareota am saOQ34 par salon ofwatarcoraunad. with
.
an annual eanaunpten of 788.400 saaom. An annual ttotida coat ol SIS • addad. attunmg T gallon of tHoctia
• usadannualyatSISpar^kxi. Ttete(a)a«2^96annua^tornotrMtnwfit
nm
ohieh cannot ba quantified An untmaisd towar raquttv* a high
aciMty raiaiad to aystam etogairfl and d«w tena: aAfitionai btocide «x« acid
Hal damanda inewrad by B» purchase of a naw cyMm.
A-27
-------
APPENDIX B
NPDES DISCHARGE UMITS
B-1
-------
IS
Is
I I
•
I
•n
AJ*J
!J
II
1- 1
If 1
f! !
*3 J
fi |
fS a
H *
.« *
•8 1
!| I
5lH
iiii
ns a
lie *
2*5** •*
' !!
=1-3
ll|
III
Sill
inn 10 w w
i
3i555SS5 S
•Sfffffi.
^%«4
«g »-I*M
sra
•sis
S-5S
*I*
-r"
•• ••
• b •
;
I
s
a
• *<
~~ SffffS
irilill^--
-iillliili? i
ihiiiiii
i!:3lliilili ^
*4£«40*c^M«<«l«M4fjo£ Q jrf
EaoPQQOQUpUp 2
s
?:?ii
I!
i;;
• •- . «
J!
B-2
-------
•J
S3
si
S*
II
SB-
B-3
-------
if
I
i?
11 .
II I
••
-------
S s
i
2i
C. £.£.
£ ==
*s
"L
^
H
S5
n
c
• , c
i fc~
B- 4 S
a i !l
il
"s
• N
0
2
3
$
•S3
95
23
i!
C u
% o
Hi
il
*f *
'I1 B
WI i
Pr; -• ><
.ai s
"iT *
ifl^S
|s|wl
^»g,a3
?M5
"1
2^
fi
^1
H — O
O1 <93Q • <9 •*
i"« IS
Ma> 'S
•• ? « X
B-5
-------
• «J
fi°
If
JI
!*
11
25
«.
If
rt
i
5'
*
I
j
i
- *
iflll!
*« ^
i -i
s
i
*4 f4 »< *4 r*
•OS'S
8?j
zte
7-S «' II
:»? i ?J
I
I
«
Ir
S*!!
IS 3
*-*
-r
P'l
te
^|l
?5SS
58--S
I
*
S
€
§
I
•*
I
I
!
j
43
V «
oU
SS2 S5
iKlsl*
s
^1
JS
1,
>J
^1
^1
J*
fi
5 =
u
•i
JJ
—* a
•oi
8^
JJ
!0
B-6
-------
I
1!
mm nnn
i:
if
I
- a
!
*
H *
§
i i
*
1 1
a
i
!
i
£«£££££
5-o> -o
-« o - S
ffa ** "*
g
S1 S'JS'S.
I -~-
•& M —t «*.
•v *4 O r<
I
ill
•55
: 'i
° s=
s Is
11
_8
• 4J •
i ! S^
i 8s
I Is
«ri *k
»3>J
fSJS
?
•^
e-irsf?
'iB'liilr
t~* a«a«'aT3x.**5 i B o Q
Plllllffilel
_. w«2 «• fi 9 S & Vwi .*»*.*
2r|-lll|i|m
*.1.POQQQ3 POOD
,- ^1
I n M ft fir
i • a •*
|3i II
• S
B-7
-------
!
J
tttt
1!!!!!! I! !! ! !!!
I
I,
•0 I?
c n
"
B-8 •
-------
HQ&
PR6M DEFT
:s.}< SM): NO.OO: P.01
MDRPOX WAL BASS -
POINT 8CUCB Mfr^AyiCT RCM
OOTJOJL RM3ER<3)
Of ttf
RjOT
WOO feraJl No. VAtf 14421
F»et Sh««i ft|t _. _ of _
UKKCBD April -IS. 19*4
. rOINT
10 »U1£U3HBT BAT
cr enJUBir. uusuu. *crivrriEj.
AND/CM (OCRAL " '
I 142
K/A
•.•2 W
IT. irii. 41***, mUtt»m, put. Hfftixt.
1m
K/A
M/Q
B-9
-------
h'.'tflSt MCr? ENVIrOMENTftL PESM DEFT
Jun 23.94 9:04 No.007 P.CO
fer.it no.
of
CUIFAU. NUUEBU3) rujv
_
WQMED April IS, 1»94 " -
«nvrriB.
SdwjLiEJissrcomMi
t.44 us I f,r tfttM,
• .•3« 10 t d*. iw«.
aummini/iiMi/ii/iiuii.
""
.•••»» MO hr
M/0 » «».
H/0 I 1J-
» nr. g tii/,,1 ^ ^ > ^
n.[
-------
COrtNflVBAiE MGF.' ENVI&3MENTAL PR6M DE?T
Jun :3.*4 -J:04 MO.Ov? F.O:
VPCES Pcrait Me. VA*e«4421
Fact ShMt
ICRfOU KAVAL BASS
POINT SOSOJ DISCHARQBS OHO
April 15. 1994
RIVER
B-11
-------
CCHNflVBflSE NORF ENVIROflENTAL PRtsM DEPT
Jun 23.-J4 9:05 No.007 P.rjj
J2?J!!!"1' "»• VA8«4421
rot Sheet Pat* 0< **
April 137^994 "
B-12
-------
COHNMVBflSE tWF EMVIR3MENTAL FRSH DEPT
Jun 23,9J ?:•>; No.007 F.uf
Jfe.
'•et Sheet rtge , Of
WTOMH) April 15, 1994 "
W-WT Bauer
B-13
-------
-Hit NOr.F ENVl?0-1£:iTflL F"<3« DEPT
3un 23.J4 «:i?e No.007
^ """^""-T «*»tu. iiip.^.
— "• T*tgt«t«*T fn«^
g. tt€M »-
-------
APPENDIX C
MONITORING DATA
C-1
-------
Micrebac Mid AtUntic Division
C04 Morria Ccivc
B«wport N«u* VA T3COS
AIR • FUEL • WATER • FOOD • WASTES
* *
CERTIFICATE OF ANALYSIS
Public Horka C«nt«r
Attn: M*rri!l Ajhcr*ft
Environmental D«p«rtn«nt,Zl40
»- VA 23511-3095
?«rsiit No
P.O. N6:470-«-B-4«9S
Date K«port«4 4/13/94
Cat* R«c«iv«d 4/04/94
Ord«r 80 9404-00108
Invoie* Bo 0
Cust I
HOO:
Sublet: VFDK/OOWM.L 1^7 SAMPLED IT: A. 8. CAKPEl
MUIHS ***. MW ... nr m
31
-au*
-"-*
It
:.t
3.H
l.S.
ti/t
unu/s:
lira
«!.!!
««.::
«.:«
<£.«
i.:
HrJ
*?/:
K/i
K/I
s.;5
2.1'
U*
.n
.n
i;.33 Mi.:
It.SJ ^.:
4/U/HU:'! 4U.i
4/r/S«U:U «,7
4/SJ/S4 ll.JS 35.1
4/M/S4:;:!! •«.-
3
IB
cn
* •
BC
n
S3
TJ
n
e:
1.7
en
u
n
1.1
tj
n
S3
C-2
-------
MVT MC HVlMMOTtt. U*OUr<*T
J-WO. CMt fM
MrtlftU OSH-WW
SMFU.ttM.TtlS «0>0«T
KM e*. cm M
•owou wasii
Ni tttOOOt
M Crtftr •«.! QS200I
tavU» i »n
s*a»t« Mtriu uaitt
ln*»tH»l itet* CMti
Pctm CM§ i
eoaiKs
u •.oor
».17»
O.OOT oj/os/ifN OTM es/io/im u:u:n 200 r
O.OB es/es/WK OTSO a/io/im tiiu.oo joo.'r
Imtnant
CoiMntai
<«rymrai»r
C-3
-------
OT me
•i« x-vw. e«* «
•crtotfc. Vfninl* ZBU
«ae«) **I-«B« r« (to*)
Mui.ni* aratt
KMKtt, COMM
•otrau: * 0*11
Ml «U>300f MSI ***•
nstoos
uau»
ln*»tr»»l VMM C»*M
M.I
n >
laapU Mtrlu
I 9J/11/W*
MM « M/flt^t^H
COXIM TOkO
MC*
CCUKT CDuter «wu.n»
LT U»JTS mt. •*« »»• •*" "**
UITIM,
KU
to5 " 2S S S «SS^ «» es/wm* «.».« Moir cu
Tte I «|ft IM*«- WP-rOw •««• «•
•e to tk* Inttncmc m«nl«nit>.
Convitu
tt* lit* kl*lt
rwut
/
/
*v«
C-4
-------
xu
H
t —i -^ -xj r ^* •
SiU. K »Q» IQI
— « s — .
b-IMWl > • 4
*E«*£t!2
w •-« :$c
&*»-«.«<
li
TO
I!
'I'
iH
n
t
!
§
(V
~ §
1C
e
u
&
»
£
e
i !!
• t«
II
»
V
•
!•
I
!
cl u^ ' oi I o! I o
*ft
•<«
>f
« •
31
*l •
•
-r ^ ™- ^ —• • •
* . • « . mta m •
| • «• • « • •
I i « • « «fl 3 «
I i «- ««o- • ^
I i • a « • •
•\
«
::
• V
M
M —
• ••
• «
• • •
•
•
: :!
1 32
i a:
•O- • 41
a • •
•«»• « «•
• mm
a i •
o •
i* •
* a • • § • • •
32 «•§• «<•• S
52' 2"*" «*• •
« -a . « •« • * . •
32.
All
S
2%
• u
.2
•
r
i
^
•
!!
if
IP
il:
fe':
film:
:!
1:1
'< i
C-5
-------
Mkrofeac Mid-Atlantic Division
DATE:
.LOCATION:
DATS/TIME RECEIVED:
CRAB
LABORATORY I.O«:
SAMPLES:
DATE/TIME SAMPLES:
SAMPLE I:
PEfiMIT
Al« . FUEL • WATER . FOOD • WASTES
CERTIFICATE OF ANALYSIS
. «avy Public Hocks Center
KnvirotuMntal Department
Bldg. 2140
Morfolk, VA 23511-6038
Attn.: Merrill Ashcraft
Contract
February 21,1993
02/04/93 f 1€30
02/04/93 t 1140
5471-5475
ANALYSIS
0*0
TOC
PH
Phenol
LIMITS
XXX
XXX
6-9
0.04
Phosphorous 0.69
Cadaiaa
Copper
Chromiua
Zlr.e
Nickel
Ft,ow: 0.40
0.04
XXX
0.11
0.22
XXX
Liters/See
HSTHOO/H9L
413
415
170
420
365.
213.
.1
.1
.1
.2
.2
.1
220.1
218.
289.
249.
1
1
1
1
1
RESULT
.
5
e>g/L"
•s/t
**• 6.92 9 13.7»c
0.01
0.05
0.
0.
0.
0.
0.
01
OS
10
05
1
0.02
0.55
<0.01
<0.05
<0.1
0.28
<0.1
•g/L
«g/L
eg/L
•9/L
•g/L
»g/L
•g/L
AMALYST
C.
J.
B.
L.
L.
L.
L.
L.
L.
L.
Martino
Hlllett
Gates
Catklll
Caskill
Rivera
Rivera
Rivera
Rivera
M
Rivera
DATE/TIME
ANALYZES
"*CS/1«/S3
5900
02/11/9.3
1SOO
02/04/93
1147
92/09/9:1
1441
02/11/93
0830 '
02/09/93
1000
02/09/93
0815
02/09/93
0940
,02/09/93
02/09/93
0830
9
9
9
9
9
9
9
9
9
9
C-6
-------
•I*. X-U4. C*» «M
•«r*»U.
C«t» US-MSO lot (Ml) US-
CMPU
"•« OMV9MS Ml
•US CM COM
Mtreu v» ZSSii
ceeti 4u.»n«
LT eiua
i
i
s.
» i vsj ccou
HMTlx I L
¥3
axucTtn
C»(t*cti«n Slt« V-53 COOLIW TCUCS
Iwt
t**utt
CMtcct
MM
Ttav
Tim
eu_t
••30* U ••/!.
0.01»
0.053
0.01S U «W
o.uz
init
wiit
•.oot
•.eer
e.oo*
OJ1S
•.tee
O.OOZ
•*/ei/«s UM
w/81/fi mj
•*/ei/n MM
e»/«im u»
•*/oi/n use
09/91yQ USB
w/oim use
ttmm
120
tno
me
me
0»/07yw i3gg
H3»
joo.r
lee.r
ao.r
zee.r
ax.r
tse.i
no.7
Mt
mt
ttt
u*
ttt
IM
Mt
KSUUS LEGEKD
B-BOOWIHEUrffUtfT
UMIT
LAB MANAGER:
C-7
-------
APPENDIX D
MATERIAL SAFETY DATA SHEETS
D-1
-------
s«.y.eag?A!Bgfl
or SIVSBBEII urn
DKPATS SXI» MTm rWSWMWTO COKTACT
NATtR. FOR AT UAST IS MIKITTCS.
wtom *TTH man HATCH, mown nemo eunttn AM
C IVII*A!EA» OOCOT TBUlUJg VOXSTlMi. CST MCO76A7*
«TT&»TIO«. MKVMl OtVX AMTTRZM BY HOOTO TO AH
PCMSOX.
nmnraiBrra AOT tisrm on TOT TOGA
rAei
SOOT CM SIMCATR - OUI •I344-O*-*
D-2
-------
iwna raa AT IMS? is towns, err
H1TR FRR2U! MATCH
RtMOVX CO*TAx:mATT3
'MxsnoN em MXUC on MATS*, tmaat
CST xeatcAL ATresTto*.
C»4«S4.00-i.S03SP. U4994.oa-l-S03«r
D-3
-------
ATERIAL g^FETY DATA SHEEI
r-t . i_< ii/-n, wi/-u fc- i I ur\ i r\ xjnt^c I maturing w R>y_?ft
cAS2-«:oo-itoc EST-MOM-rRi i-8oo-3*3-4soe Sg^j?* <^f-f***; 3c3-ias-i;i;;•
.-. i L. umm^-- ^du!-!>r^ . t-"OQ~*?'t-SniflC
li^TlcS^iSR DRIVE
tlVO^IA, MICHIGAS 48130
. FRSPARED BT: REGCZJITORr
( Ott 08/24/93
Wj'ilirj'i^Tp rjg j^g
rrT..H,IJM> KT U «TT*H
IUCKICMCY PHONE MO
313-<88-Sget!
if-**
UHOJ^-MAJUM**r MLAJCN/A^IOT w^ucAfcAjMUNdf *n6wHj>>6tWw4_>B.-H»u*iiiU twosUKifui.
atTga^i-txncrr.txom' •nam_n.v.TMwaxm) JJMTT v
-------
WTERiALSAFETY DATASHggT
QUO k.
ctxnm* P
JSCO-IO
&:
.4
REGTSTJUTIOir NO. 87S-14O
--v -• ^^w<« |t*v« • f^J^M WU
?^tH5i?iMf»
»M:
D-5
-------
teil
-C-ci
DRIVE
LIVOSIA, MICHIGAN 48190
PREPARED BY: REGULATORY
OK 02/19/94
313-498-aceg
EPA REGISTERED PRODUCT »S73-138
9-CHLOR-2 KITHYL-4-ISOTHIA20LM
3-OHE (CAS »26172-93-4)
2-M2THYL-4-JSOTHIAZOLIK-3-OHS
(CAS »3682-20-4)
<2
.33
TiVO.l,STSi 0.3 TOR TO
ISOTHTAJOLOIIES AS »"
Rgcoiegaaga BY SCPPS.ISR
LD80 497 MG/KG (ORAL)
LD30 660 KG/KG (DERMAL)
J.1RH
" UNIT
J1C/M
M1W
.**eouctl AOT JflTROCZH .
: C*O/TI — eons?
)iilVK TO i
SJil.M "AMI EVSS. 3L'%
Mi! TU M^iJ HAVrMf.? g.r
!. HARMFUL SF XXHAUCD. HARMFUL IF
THROUGH SJCIH. KAY Sff FATALIF SHALLOWSat
X.CMOMC KAY CAUSE ALLERGIC SXZH REACTIOX.
Of
sSMtwr itNiiTlVE SHU AHU WLH*. U^'AJUOJ ^'L^aUHAKI AUJIU'^IUJ!
•ft* HU umc'
AIR. APPLY ARTIFICIAL RESPIRATIOK IF HEE3E3.
PLOSH^THOROCCTLY^WITH FRESH HATER, FOR AT LEAST IS MIJTOTSS, GET
REPORTABLB QOAXTZTT (R.Q.) OF PROOOCT: D002. 1OO LBS.
D-6
-------
KYDROX235 (£310-73-2]
a
D-7
-------
MATERIAL SAFETY DATA SHEET
V 9* \ I fcaT »•• »^» • • "" ^» • » «^v » • » » ^^1 Bb^MK * I I
L-CAAI-a:00-5:00 IST-MOJf-JTi: 1-600-443-4800
, ICHIGAS 48 ISC
FKXPAR2D 3*: XSCC^ATOKT
OS 07/16/91
ZPA R2GISTRATIOS 3D.
X.04HOMC SAMS AS ACStS
IEWEHQENCY AND
t. rNMALATlON
rSOROaG2£Y NITS fRSSH HATER. GZ7 MEDICAt
ACT
JLOSH WZ7H 7H2SH WA7SX, MASH WITH
REMOVE CORTAMIMA7EO CtitSES ABU
CaCOKSCIOCS PSRSON.
"* *"y^ _ a.^«j»«ve. ww«« *«^**«4h«v AW c^>ur^ x . ^sfl
IT TSOZ2». THAW AHD MIX TO MAZS CSABSJ
,-g.jlAjUJ MLTUJUI LAK'SA. ^.UJiirii
CXTSRIKC OPES BODIES 07 WATEDl
D-8
-------
____^__ _____^'*" .;r.igy,*'' "»*i ^ "-./•••.'••••
' WTERJAL SA^TV DATASJ-jFgf__ |'oy,,;L h"
Hi 1— jtOO — ^43-
I
3:3-<58-aoeo
XCMIOMC SAKE AS ACUTE
AT «AST IS MIKC7K, GET
GIVE «« « HAT«
VOMIT1W. GET KWICAt ATT^IOK.
0-9
-------
Material Safety
D-10
-------
•I
SECTION 4. REACTIVITY HAZARD DATA
MAXMOOUS POUTUCMUATIOM
O M*rwwr
CD W» M»4 Qtnt
0* "**•««
SECTION 5 - HEALTH HAZARD DATA
'nouns a i
Gfvmn a!
B if*
Q *M
m*j MUM Ittituten IK"
Nm.
OiKONICVHCTS
EMtKOItHCr FIKST AIO MOCtOUIICS -
«r«e«i
w«n
»ith M^ Mfl
*•••*• (• ItMh «li.
auc*
fitmk mlaiy ccd «««, (Mn MW -w««»4
SECTION 6. CONTROL AND PROTECTIVE MEASURES
w Uc*
*•* •«• •«<
SECTION7.PRECAUTIONS FOR SAFE HANDLING AND USE/ LEAK PROCEDURES
Stay w MW*»U OMH rwl4m kua > 9«Uon eonulrwr for «spou<.
D-11
-------
(4
Saline,
„•===.=
MATERIAL SAFfiTY DATA SHEET
PRODUCT NAME:
DATE PREPARED:
EMERGENCY PHONE I-
™>°"t*r
(703) 461-0200
FORMULA 1109 MANUFACTURED FOR: /
M«X '. 1990 COA3Tu«t tT'
P- 0. lOX Hit
(703)'461-(J2CO
l-0«-l
marast P«TA
1.04
Ithyl.n. tfelo«««« CAS Mo. §(.49.7
-BMoareff Pftia
3»S
«/
i
4.S
4.S
Appro*, o.l
Kot
»v*U»Si«
or.i
rtti en N*b«»
D-12
-------
D-13
-------
Material Safety Data Sheet
TN« USDS totKfttt «Bfi OSHA'l ttaurd C«m*iunte»Uon
Sltnoaid }fl CM 19.10.1300 M* O*MA rOAU t74.
MfItlMJ
MM*
UP.
P. 0. IPX
CMCICCllCT «ClfOMlC
(703) t£;.-C2QC
TA
(703) Ml-0200
1
fTngl hfri.ng
HOTlCtJ JUOfltlUHTlAltB OH IHOI*eCTT«JTBATA
SECTION 1. MATEHUL tDlNTlFiCATION AND INFQHMAT1QM'
•OfUMw M/A « N*t
MA 3)
NX UMM 0*U Oftlr
a . PHYSICAL / CHEMICAL
D-14
-------
strong Oxidising A<«ata, Strong
SECT10K 5 » HEALTH HAZARD DATA
™^~*""*'~~—"~IIMMi»MM I .
,pr«y or El.t vin c*u»«
cuCTotMcy rowAiO f noegau»I
"
g^—"' —'""" 'Tr™«» detain .M foctv,,,. -^TT:
Star:—.- ri? --1 - a
^- -, ^.fc TOt „ q^^ ^ ^^^^ .p^^ „_ -• T-"T' Tnnwj
to«»wQ,>t
-------
•^•i^^^^^J^^g
HSaSc^adodo,
sgcnoNj^
ilH^O^^I
ssaSF^i
^-^ssSSSS
«*t«r re« ta ^.,
g«d Coat^B.^
- ~~
D-16
-------
VH4TIUITIOH
Kf CU1MCMCNTS
.
~
^
D-17
-------
APPENDIX E
HAMPTON ROADS SANITATION DISTRICT
COOLING TOWER WASTE DISCHARGE POLICY
INDUSTIRAL WASTEWATER POLLUTANT LIMITATIONS
AND DISCHARGE REQUIREMENTS
E-1
-------
COOLING TOWER WASTt DISCHARGE POLICY
Cooling tower chemicals contalninfl the following constituents should not be
Oh,— ' . W MW*r tvst*m without prior authorization from the Industrial Waste
1) Copper (Cu)
2) Chromium (Cr)
3) Zinc (Zn)
4) Tributyl tin fTBT)
.K« . M*terial S*f«tyData Sheets (MSDS] may not always reflect the presence of the
I?.^ft?,!tUimS',Th* "*" * rMDC"«*l« f°r •n*"ri«fl that these parameters are not
present m their cooling tower chemicals.
""8 tow*r chwnfc^^Mtw to the sewer system are also
fimnation» <««»chm«m 1 J and to Section 301 (attachment 2)
U*trW WMtiw»Mr Oi»charge Regulations, terns- (h).'(n). (r). (s).
Wastes generated as a result of cooling tower system start-up cleaning, periodic
*r*nCi'-r f SVStem shut*down an«« °<»t «>• discharged to the District's system
ut specific authorization from the Industrial Waste Division. The District may
require that the wastewater be collected from these operations and held until analysis
showmg compliance with District limitations is received and District authorization is
given.
m.» * tOW*f di*cnarO«8 wnfcn •» «ccepted by the District must be
nwtered for billing purposes. Billing based on estimates or proration of short duration
metering studies will not be allowed.
The use of coofing tower maintenance chemicals which contain ehospJboruAiPJ.
usuanypresent in the form phosphate JPOJ. may result In a surcharge fo/total
'
h» n-B of 6 mfl/1' Th» ««w*wot is in accordance with
tho Distnct s Rate Schedule and i* assessed at the rate of $114.00 per hundred
pounds.
10/5/92
Attachment
E-2
-------
INDUSTRIAL WASTEWATER POLLUTANT LIMITATIONS
(ATTACHMENT 1)
ALL PARAMETERS IN mg/I EXCEPT pH
FLOW IN THOUSAND GALLONS PER DAY (K)
PARAMETER
0-1 OK
10-20JC
. 2O-30K
30-40K
40-200K
20CWOOK
••••••••*•«««•••••«•«•«••*»•»»•••«•••«••••••••••••••••••«••••••«
ARSENIC
CADMIUM
•• CHROMIUM
•COPPER
CYANIDE
LEAD
MERCURY
NICKEL
PHENOLIC
COMPOUNDS
SILVER
• ZINC
O&G (NON-
SAPONIFIABLE)
PH
•NOTE: SILVER
0.5
0.5
10.0
10.0
2.5
5.0
0.05
5.0
5.0
•NOTE
10.0
500
feS.O
GPD
0-1000
6.25
0.4
0.4
8.0
8.0
2.0
4.0
0.04
4.0
4.0
1.0
8.0
400
2:5.0
0.3
0.3
6.0
6.0
1.5
3.0
0.03
3.0
3.0
0.75
6.0
300
£5.0
GPD
0.2
0.2
4.0
4.0
1.0
2.0
0.02
2.0
2.0
0.5
4.0
200
25.0
1000-5000
3.125
0.1
0.1
2.0
2.0
0.5
1.0
0.01
1.0
1.0
0.25
2.0
100
2:5.0
GPD
0.05
0.05
1.0
1.0
0.25
0.5
0.005
0.5
0.5 -
0.125
1.0
50
25.0
5000-10000
1.25
E-3
-------
PART HI
DISCHARGE REQUIREMENTS
(ATTACHMENT 2)
301 Prohibited Wayflp Dteehtroga
No person shall discharge or causa to be discharged into any portion of
the sewerage system, directly or indirectly, any wastes which may violate
any law or governmental regulation or have an adverse or harmful effect
on the sewerage system, maintenance personnel, wastewater treatment
. plant personnel, processes, or equipment, treatment plant effluent quality,
sludge quality, public or private property, or which may otherwise
endanger the public, the local environment or create a nuisance.
Discharges of the following are prohibited:
(a) Any gasoline, benzene, naphtha, solvent, fuel oil or any liquid.
solid, or gas that may cause flammable or explosive conditions.
including, but not limited to, wastestreams with a closed cup
flashpoint of less than 140 degrees Fahrenheit or 60 degrees
Centigrade using test methods specified in 40 CFR 261.21.
(b) Any toxic or poisonous solids, liquids or gases in such quantities
that, alone or in combination with other wastewater constituents.
may interfere with tha sewage treatment process or sludge
disposal, cause acute worker hearth and safety problems, materially
increase the cost of treatment, or constitute a hazard to any
beneficial stream use. including recreation, ascribed to the receiving
waters of the effluent from the sewage treatment plant.
(c) Any waste having a pH lower than 5.0 or having any detrimental
characteristics that may cause injury or damage to persons or
property.
(d) Any solids or viscous substances that may cause obstruction to
flow or be detrimental to sewerage system operations. These
objectionable substances include, but are not limited to. asphalt.
dead animals, offal, ashes, sand. mud. straw, industrial process
shavings, metals, glass, rags, feathers, tar. plastics, wood, whole
blood, paunch manure, bones, hair and fleshings, entrails, paper
dishes, paper cups, milk containers, or other similar paper products.
either whole or ground.
(el Any significant quantities of unpolluted water such as rainwater,
stormwater. groundwater. street drainage, yard drainage, water
from yard fountains pond or lawnsprays.
E-4
-------
-------
in
(t) Any quantities of radioactive material wastes which are
violations of applicable local. State, and Federal regulations.
(ul Any significant quantities of inorganic material.
(v) Any discharge of any pollutant released at a flow rate and/or
pollutant concentration that would result in interference, cause
adverse effects or pass through it the treatment plant.
(w) Any discharge not in compliance with all standards as set forth in
40 CFR Chapter I. Suochapter N. Parts 401-471 (National
Categorical Standards!.
Cx) Any significant quantity of Total Toxic Organics (TTO) which
exceeds 2.13 mg/1, or in which any one toxic organic compound
exceeds 1.0 mg/J, or in which the STEX {Benzene. Toluene.
Ethylbenzene and Xylene) concentration exceeds 1.0 mg/1.
(V) Concentrations of any constituent fisted in Appendix 0 which
exceed the particular limitations set forth therein will not be
discharged by any person who discharges 50,000 gallons or more
or. any day of the calendar year, directly or indirectly, into the
sewerage system. Dischargers with a flow of less than, or
significantly greater than, 50,000 gallons per day will be given
limitations for constituents included in Appendix D on a case-by-
case basis, taking into consideration, but not limited to. the
following:
1) Quantity, rate, and method of discharge.
2) Proximity to the District treatment plant receiving the waste.
3) Size and type of the treatment plant which receives the waste.
4) Method of sludge disposal employed by the treatment plant
receiving the wastes.
5) Other discharges to the same treatment plant which may, in
combination with the aforementioned discharge, form toxic
substances or any constituent having adverse effects on
treatment structures and processes or which cause a nuisance.
E-6
-------
APPENDIX F
MSDS FOR DIAS-AID TOWER TREATMENT XP-300
F-1
-------
D/A*
MATERIAL SAFETY DATA SHEET
XP-300
Revision Oats: 11/25/32
DIAS, Incorporated
4510 Commercial Avt.
Kalamazoo, Ml 49001
Phone 1-600-332-OIAS
24 Hour Emergency Phonn
1400-442-4112
SECTION 1
OSHA HAZABO CLASSIFICATIONS
Corrosnrt to tyts and insatmg to skin.
SECTION2
HAZARDOUS COMPONENTS
Th« componams of n»s product compos* propntarv information.
SECTION 3
PRECAUTIONARY LAB a INFORMATION
This stcwxi rat appticaM* to non-Moeidn.
SECTION 4
FIRST AJI) INFORMATION
ElfE EXPOSURE fkah immtdiataly with copious (mounts of Up wntt or normal stint (roromum of 15 minutas). Taka t xposad individual
o • hiatm ewt proftssional. prtftnbly in oprttwlmotojut for funhtr tvabMOon.
ami EXMSOTE Wish txpostd ins with pUnty of Map and want foput washing. Rtflwvtconuminittdclothipaindwishtnof.
ouchiy btfon reust. If nntion ptrsists consult i huUi an
WMMATTON: Hczpesun^r Wwlrton is SusptctidL inirntdaaly mow npostd Mmdual to frMh air. If individual Mptriencts nawaa.
Nadachfc diomtss. has difficulty in brentong or is cyinooe. snik i htaWi cart prodssionai imiwdiattly.
WSfSTKHt OONOTIOTUCEyOMrT1r^Rinsti«w«hw*copiousanvHWttof*«tSforin^
swrnaeh conttna by shmiy ohring ont (1) to MO 01 glassas of w»t*r or mitt. Avoid smog alcohol or aicohol ralawd products. In cam
wh«r« >dw «al «s swn^omMosa. comates* or convulsing. 00 NOT GIVE RUIOS BY MOtmt In cast of Jraarmonal Jngwoon of tha
product SMk madreal tssounc* •MMCoaaly: taka individual to ntarest mtdical fae*».
, ^S^. *"*«»'* *"«•"• ****** «weo*«l cUmagt may comraindicau th« usa of gastric lavaga. Traat
«ymptoms.CaBOIAS,lnc. for product information at HOO-3E-342?; ,
SECTIONS
PRIMARY ROUTES OF EXPOSURE
Bttcts fma aou txpasarc
tk£ wS^Jdmaaar^1'**0 "*** **** **" mcdtf*t* W **""* (wfl°»ion» 0«P«H»9 on th« length of axposurt. solutwn coneantra-
SkaExpewrr BnnAfTtlrrtetmi^dvptnd on solubcflstra>qth. length of tzposuraandfntaidm«asuns.
May causa irmition or eorrosicnof mucous mtmeranes and th* lur^ Expo*td indiwhjaJs *houkJ b« nwonortd.
F-2
-------
TOWCOLOGICAL INFORMATION
AcM*EH*ctc
Acuta Onl LOSft 1000 mfl/fcj
Acu«0«nMlLDSD:
Acuu Mutation ICSO:
Mid BtRMRt imtitjoa
Notwdmciaiatniidzttion.
NombimwL
| SICT10N7
\ SECTION 1
ApfWfrfiCt
tUnr
Polity wmtrl
VapnrPrTfftvr^
OxMoing/Rtducing Prop
E?
-------
SKTION12 SATISFACTORY MATEHMIS OF CONSTRUCTION
Heogtas
Ttfcn
PVC
lena-n Rubbir
tar Tht maufials bmlabovt havt ta«n tasttd men XP-» Th« KM of oflMr matariah not feBadabovtrrwybt hazardous and rasuft in
*inaflM u wch minnals and otfttr proparty and ptrsonal irqunts. No data concan»QSUchliu»flalsn«teadabov«siiottidbt«npb€d
[SECTION 13 SPIU. UEAK. AND otsrosAi PBOCEDURES
f«fI2^±L0i^^^^f2^
*B »^*n a (•«««». «lh«w,o»noMO»rk1ogtDOtjiimt«i
-------
No eompcnwa of dw product arafead.
CWA (daw Wa**rAe* No eoesponans of Ma product *ri fatad.
PDA: This product aat approvtd tor food contact urn.
ISCfc Al components art tsstd on TSCA irwtmory.
IWUL- This product amctrtgistaradpatacidt.
NfPA RAHNC1 Htalft Z Ramraabfey I; RtactMy 1
Vinous rauftgfc To Know Acs
ehtmicvis or inms. RMM cenoct OIAS. bic
a »v»itN« riao^ yw ft»^ funhtf informatxyi o^
ttriornwbon on this M«an») S«frty 0y kind, txprm of imeW. eooetming aw product inctodinfl NO
IMPUHJ WARRANTY Of MESCHANTASOnY Ofl RTNKS Of THE GOODS fOR ANY OTHER PARTICUUfl PURPOSE. No nch
wtrramw sh«l bt mpftd by lew and no tgtnt of Mlif is »u9wrart to ifiv Uas w«mmy in my w«y txctpt in vmono wiou
setofic rtfertne* to Ms wimmy.
Th« cxdusivt rtnwdy tfl*na ultr shd tx i d*« for datna^tt natn ncttd 0M purcfcw prica tf iht product, widwut
«9»rd to whether tutk • dwn a butd upon brtieh of vwwoy er ton
Any coouovtuy or d*im »rijingout of or rdtting to ow rennet or brttch flitrtof. shaS bi sttdtd by irtetntion m tccor-
oanct WMII tht ecmmtjuil •rwraoon mitt of KM Amtnew Arbitration Assooaaon. and judgtmam upon dw award ranotraa
oy ttw arbornortil m»y bt tnarad in any court ftawnj juri$o»CBcn thtrtot
i
F-5
------- |