# EPA 440/1-76/084 

# ' 

# DRAFT

Supplement

# For 

# PRETREATMENT tothe DevelopmentDocument forthe 

# STEAM

# ELECTRIC 

# POWERGENERATING

PointSourceCategory

U.S.ENVIRONMENTALPROTECTIONAGENCY 

# NOVEMBER 1976

### SUPPLEMENTFOR PRETREATMENT TO THEDEVELOPMENT DOCUMENT

FOR THE
STEAM ELECTRIC POWER GENERATING POINT SOURCE CATEGORY

Russell E. Train

Administrator

AndrewW. Breidenbach, Ph.D. Assistant Administrator forWater and Hazardous Materials Eckardt C. Beck Deputy Assistant Administrator for Water Planning and Standards

Robert B. Schaffer Director, Effluent Guidelines Division JohnLum Project Officer

NOVEMBER 1976

Effluent GuidelinesDivision Office of 

### Water and Hazardous Materials U.S. Environmental ProtectionAgency Washington, D.C. 20460

### ABSTRACT



### This document presents the findings to date of an extensive study of that section of the Steam Electric Power Generating Industry which discharges industrial wastes topublicly owned treatment works (POTW). 

### Its purpose isto develop pretreatment standards to implement section 307(b) of the Federal Water Pol1

### ution Control Act. Pretreatment standards, recommended in

### Section I1 of this report set forth the degree of effluent reduction achievable through the application of control technology currently available. These pretreatment standards setforth the degree of effluent reduction achievable through application of the available demonstrated control t'echnology, processes, operating methods, or other alternatives. These standards must be achieved no laterthan three (3)years from the date of promulgation. Supporting data and rationale for development of pretreatment standards are contained in this report.

### TABLE OF CONTENTS 

### Page ABSTRACT NOTICE TABLE OF CONTENTS 

### iii LIST OF FIGURES 

### vii LIST OF TABLES I. 

### CONCLUSIONS 11. RECOMMENDATIONS I II. 

### INTRODUCTION General Background Purpose and Authority Scope of Work and Technical Approach General Descriptionof the Industry Process Description Publicly-Owned Treatment Works (POTW) IV. 

### INDUSTRY CATEGORIZATION Introduction Industry Categorization Factors Considered Age Size Fuel Geography Mode of Operation Raw Water Quality Volume of Water Used Pretreatment Technology



### iiiTABLE OF CONTENTS (CONTINUED) Page V. WATER USE AND WASTE CHARACTERIZATION V-1 Introduction V-1 Principles of Operation of Steam Electric Power Plant V-1 Water Use and Waste Characterization by Category V-6 Condenser Cooling Water V-6 Water Treatment V-23 Demineralizer Boi1 er Blowdown Maintenance Cleaning Ash Handling Systems V-46 

### Air Pollution Control Equipment 

### V

# -55 The POTW Process V-60 Effects of Steam-Electric Wastewaters On POTWs V-67 VI. SELECTION OF POLLUTANT PARAMETERS VI-1 Introduction VI-1 Rationale for the Selection of Pollutant Parameters Properties of Selected Pollutant Parameters VI-2 Pol1 utants Rejected VI-17

### TABLE OF CONTENTS (CONTINUED)



### VII. TREATMENT AND CONTROL TECHNOLOGY Introduction End-of-Pipe Treatment Technology Treatment ofMajor Pollutants End-of-Pipe Technology for 

### Major Waste Streams Water Management In-Plant Control Techniques Material Substitution Water Conservation and Wastewater Reuse 

### VIII. COST, ENERGY AND 

### OTHER NON WATER QUALITY ASPECTS



### IX. X. 

### XI XI1 Introduction Cost Reference and Rationale Costs for Pretreatment Levels of Pretreatment Cost Estimates 

### ~l timate Disposal Energy Considerations PRETREATMENT STANDARDS ACKNOWLEDGEMENTS REFERENCES GLOSSARY Page 

### vii-1

### TABLE OF CONTENTS (CONTINUED)
Page APPENDIX A

# - STATISTICAL ANALYSIS OF HISTORICAL A-1 DATA APPENDIX 

### B

# - WATER GLOSSARY 

### B-1 APPENDIX 

## c

# - EFFECT

### OF POLLUTANTPARAMETERSON 

### TREATMENT WORKS C-1LIST OF FIGURES
Page 111-9 111-10 111-11 111-12 Principal Fuel Use by Number Principal Fuel Use by Megawatts Year of Construction by Number Year of Construction by Megawatt Process Flow Diagram Steam Electric Power Industry Wastewater Treatment Sequence Typical Boiler for Oil-Fired Furnace Single-pass Condenser Fossil-Fueled Steam Electric Power Plant 

### - Typical Flow Diagram Once-Through and Recirculating Cooling Systems Diagram of Wet Forced

# - AirCooling Tower Natural Draft Wet Cooling Tower (Counter Flow) Normal Distribution Diagram For Normalized Once-Through Usage Data Once-Through Cooling Water Use vs. Annual Production Rate 

### Normal Distribution Diagram for Normalized Cooling Water Usage Data Recirculating Cooling Water Use vs. Annual Production Rate Commonly Used Water Treatment Methods



### viiLIST OF FIGURES (CONTINUED) Page

V-28 Normal Distribution Diagram for Normalized Boiler Makeup Water Usage Data Boiler Makeup Water Use vs. Annual Production Rate Normal Distribution Diagram for Normalized Ion Exchange Water Usage Data Demineralizer Water Usage vs. Annual Production Rate Flow Diagram for Recirculating Bottom Ash System Flow Diagram for

### Air Pollution Control Scrubbing System Flow Diagram of Secondary Treatment Methods Wastewater Treatment Flow Diagram Flow Diagram for Sludge Treatment Flow Diagram of Nitrification

# - Denitrification Process Model Waste Pretreatment Plant

### - 25 MW Generating Facility Model Waste Pretreatment Plant

# - 500 MW Generating Facility Cooling Water System Blowdown Treatment



### viii

### LIST 

### OF TABLES

Total Steam Electric Plants inthe Contiguous United States Steam Electric Plants Discharging toMunicipal Sewers inthe Contiguous United States Statistical Parameters For the Three Modes of Normal Distribution

# - OnceThrough Condenser Cooling Statistical Parmeters For the Three Modes of Normal Distribution

# - Recirculating Condenser Cooling Raw Water Flows and Loadings

# - Condenser Cooling Systems Statistical Parmeters 'for the Three Modes of Normal Distribution

# - Boiler Makeup Statistical Parmeters forthe Three Modes of Normal Distribution

# - Boiler Demineral

### i zer 

### Raw Waste Flows and Loadings

# - Water Treatment Effluent Flows and Loadings

# - Water Treatment Raw Waste Flows and Loadings

# - Boiler 

### Blowdown Raw Waste Flows and Loadings

# - Maintenance Clean-ing 

### Ash Disposal Methods 

### Raw Waste Flows and Loadings-- 

### Ash Handling Effluent Flows and Loadings

# - Ash Handl

### i ng

### LIST OF TABLES (CONTINUED) 

### Page Power Plant and POTW Flows V-69 Raw Waste Flow5 and Loadings

# - Combined Discharge to POTW V-71 End-of-Pipe Treatment Methods VII-3 Solid/Liquid Separation Systems VII-4 Treatment ofMajor Pollutants VII-5 Typical Composition of Boiler Chemical Cleaning Wastes VII-12 Typical Composition of Boiler Fireside Wash Wastes VII-12 Recovery Processes for Flue Gas Desulfurization Systems VII-20 Wastewater Treatment Costs and Resulting Waste-load Characteristics for Typical Plant VIII-7 Wastewater Treatment Costs and Resulting Waste-load Characteristics for Typical Plant VIII-8 Summary of Capital Costs Oiland Gas Fired Plants

# - 25 MW Plant VIII-10 Wastewater Treatment Cost and Resulting Waste-load Characteristics forTypical Plant VIII-13 Wastewater Treatment Costs and Resulting Waste-load Characteristics forTypical Plant VIII-14 Summary of Capital Costs Coal Fired Plant VIII-15 Estimated Capital Costs

# - Chemical Wastes Pretreatment Plant VIII-20 Assumed Unit Costs VIII-21

### LIST OF 

### TABLES (CONTINUED) Page VIII-9 Operating Costs

# - Pretreatment of Low Volume and Metal Cleaning Wastes VIII-22 VIII-10 Estimated Capital Cost

# - Cooling Water System Blowdown Treatment VIII-27 VIII-11 Estimated Operating Costs-Cooling Water System Blowdown Treatment VIII-27

### DRAFT 

### SECTION I

CONCLUSIONS



### An engineering evaluation of steam electric power generating plants that discharge all or a portion of their aqueous wastes $0 publicly-owned treatment works (POTW's) was conducted to establish the basis for pretreatment standards. For the purpose of establishing such standards itwas deemed practical to subcategorize the industry into the following waste-type subcategories: Condenser Cooling System Boiler Water Pretreatment Boi1 erBlowdown Maintenance Cleaning Ash Handling Drainage Air 

### Pollution Control Devices Miscellaneous Waste Streams This subcategorization is identical to that presented in the development document for direct dischargers (14) in this industry with

### the deletion of Construction Activity and Low Level Radwastes. This subcategorization was found to be valid as examination of process characteristics, raw wastes and treated wastes were not found to be significantly different from those of direct dischargers. Conduct of the work involved contact with 49 

### steam electric power generating stations, representing 50 

### percent of the estimated 98 stationsdischarging chemicals wastes to a POTW. 

### Engineering visits and data collection were made to 22 

### stations. Sampling of raw and pretreated wastes was obtained from eight (8)stations. Additionally, prior work conducted by the EPA, 

### data collected in response to NPDES and local discharge permit monitoring, industrial effluent data, and relevant literatureprepared by 

### the EPA 

### and electrical trade journals were evaluated.

### DRAFT


### Based on the above evaluation, the following conclusions were reached:

a 

### There exists no significantdifferencebetween processes and corresponding effluents of the population of plants discharging to the POTW 

### and those of direct dischargers.

a 

### The subcategorization developed above isvalid for the purpose of establishing pretreatment standards.

a 

### Stations discharging to the POTW 

### are capable of pretreating effluents tothe degree of effluent removal attainable by application of the best practicable control technology currently available 

### (BPCTCA) for direct dischargers. A 

### survey of current industry practices has indicated that most plants provide littlepretreatment of chemical type wastes atthe present time.DRAFT SECTION 

### I1

RECOMMENDATIONS

The 

### €PA will propose standards after review and evaluation ofthe information included inthis document.

### GENERAL 

### DRAFT SECTION I11 

### INTRODUCTION

BACKGROUND 

### The involvement of the Federal Government in

### water pollution control dates back to 1948when Congress enacted the first comprehensive measure aimed specificallyat

### this problem. 

### Atthat time the Surgeon General, through the U.S. Public Health Service, was authorized to assist states in

### various ways to address the problem. The emergence of a national water pollution control program came about with the enactment of the Water Pollution Control Act of 1956 (Public Law 84-660). To date this law remains the basic law governing water pollution. Itestablishes the basic system of technical and financial assistance to states and municipalities, aswell as enforcement procedures by which legal steps can be initiated against polluters. The present program dates back to the Water QualityAct of 1965 and the Clean Water Restoration Act of 1966. Under the 1965Act, states were required to adopt water quality standards for interstatewaters, and to submit to the Federal Government, for approval, plans to implement and enforce these standards. The 1966 Act authorized Federal participation in construction of sewage treatment plants. 

### On amendment, the Water QualityAct of 1970, extended Federal activities into such areas as pollution by oil, hazardous substances, sewage from vessels, and mine drainage. Originally, pollution control activitieswere the responsibility of the U.S. Public Health Service. In 1961, the Federal Water Pollution Control Administration (FWPCA) 

### was created in the Department of Health, Education and Welfare, and in 

### 1966, the FWPCA 

### was transferred to the Department of the Interior. The name was changed in early 1970 to the Federal Water QualityAdministration and in December 1970, the Environmental Protection Agency (EPA) 

### was created by Executive Order as an independent agency outside the Department of the Interior. Executive Order 11574 on December 23, 

### 1970, established the Permit Program, requiring all industries toobtain permits for discharge of wastes intonavigable waters or their tributaries under the provisions of the 1899 River and Harbor Act (Refuse Act). The permit program immediately became involved in legal problems resulting in a court ruling that effectively stopped issuance of a significant number of permits. Itdid result in the filingwith EPA, 

### through the U.S. Army Corps of Engineers, of applications for permits which, represent aDRAFT complete inventory of industrial waste discharges. The granting of a permit under the Refuse Act was dependent on the discharge being able to meet applicable water quality standards. Although EPA could not specify methods of treatment, they could require minimum effluent levels necessary to meet water quality standards. The Federal Water Pollution Control Act Amendments of 1972 (the "Act") made a number of fundamental changes inthe approach to achieving clean water. One of the most significant changes was from a reliance on water quality related effluent limitations to a direct control of effluents through the establishment of technology-based effluent guidelines to form an additional basis, as a minimum, for issuance of discharge permits. The permit program under the 1899 Refuse Act was placed under full control of EPA, with much of the responsibility to be delegated tothe States. PURPOSE AND AUTHORITY Under the Act, the Environmental Protection Agency is charged with establishing pretreatment standards to protect the operation of publicly-owned treatment works and to prevent discharge of pollutants which pass through such works inadequately treated. As part of this Act, Section 307(b) states that the Administrator shall "publish proposed regulations establishing pretreatment standards for introduction of pollutants into treatment works (as defined inSection 212 ofthis act) which are publicly owned for those pollutantswhich are determined not to be susceptible totreatment by such treatment works orwhich would interferewith the operation of such treatment works. Pretreatment standards under this section shall specify a time for compliance not to exceed three years from the date of promulgation." This report is prepared for the purpose of developing pretreatment standards for existing sources. Pretreatment Standards for new sources are required under Section 307(c) of the Act have been promugated October of 1974, (together with the effluent guidelines for the Steam Electric Power Plant Source Category). SCOPE --- OF 

### WORK 

### AND TECHNICAL APPROACH The pretreatment standards proposed herein were developed in the following manner. The listof plants that discharge to a POTW was first studied for the purpose of determining whether separate standards would be re-quiredfor different divisions within the list. The analysis was based upon fuels used, production process employed,' wastewater pretreatment atplant sites, process employed by the POTW receiving plant wastewater, and other factors. The raw waste characteristics for each subcategory were then identified. This included an analyses of (1) the source and volume ofwater used intheDRAFT

process employed and 

### (2) the constituents (including thermal

### ) 

### of allwastewaters including constituents which result in taste, odor, and color inwater. The constituents of wastewaters which should be subject to pretreatment standards were identified. The full range of control and pretreatment technologies existing within each subcategory was identified. This included identificationofeach distinct control and pretreatment technology, including both in-plant and end-of-process technologies, which are existent or capable ofbeing designed for each subcategory. It also included an identificationofthe amount of constituents and the chemical, physical, and biological characteristics of pollutants. Effluent levels resulting from the application of each of the pretreatment and control technologies were also identified. The problems, limitations, and re1iability of each pretreatment and control technology were also identified. Inaddition, the nonwater quality environmental impact, such 

### as the effects ofthe application of such technologies upon other pollution problems, including air, and solidwaste, were also identified. The energy requirements ofeach of the control and treatment technologies were identified as we'll as the cost ofthe application ofsuch technologies. The information, as outlined above, was then evaluated in order todetermine what levels of technology are available foreffluent reduction. Inidentifying such technologies, various factors were then considered. These included the total cost ofapplication oftechnology inrelationto effluent reduction benefits tobe achieved from such application, the age of equipment and facilities involved, the process employed, the engineering aspects of the application ofvarious types of control techniques, process changes, nonwater quality environmental impact (including energy requirements), and other factors. Data for identificationand analyses were obtained from a number ofsources. These sources included EPA research information; 

### EPA, state, and local environmental personnel; trade associations; published literature; qualified technical consultation; historical information on effluent quality and quantity; and on-site visits including analytical programs and interviews atsteam electric plants throughout the United States which were known to have above average waste pretreatment facilities. All references used indeveloping the pretreatment standards reported herein are listed in Section 

### XIofthis document.DRAFT 

### Twenty-two operating plants were visited and eight were sampled. Composite samples over a sixteen hour period were obtained from these eight plants and were analyzed for parameters mentioned in Section V. 

### Information was obtained from as many as fifteen (15) plants for each waste-type subcategory. Both in-process and end-of-pipe data were obtained as a basis for determining water use rates capabilities and effluent loads. Permit application data was of value for the purposes of this study when such data covered outfalls serving only skeam electric power operations. Cost information was obtained directly from industry during plant visits, from engineering firms, equipment suppliers, and from the literature. These costs have been used to develop general capital, operating, and total costs for each pretreatment and control method. This generalized cost data and specific information obtained from plant visitswas used toestimate cost effectiveness in

### Section VIII and elsewhere in this report. Certain plants were selected for in-depth analysis from the total population of those visited. These plants were plants discharging representative waste types or exhibiting superior performance in pollutant discharge or having substantial quantities of historic effluent data. The following selection criteriawere developed and used for selection of plants tobe included in this study.

0 

### Discharge - 

### of representative wastes types Plants that discharge types or quantities of waste representative of those delineated in 

### Section IV. e 

### Water management practices Plants that had good management practices such as good process and quality control, good maintenance, water reuse, conservation, and in-plant water segregation.

a 

### Air pollution and solidwaste control Plants that had overall effective airand solid waste pollution control, in

### addition 

### toDRAFT
water pol1ution control technology. Care was taken to insure that all plants chosen have minimal discharge to the POTW and that sites are not those which exchange one form of pollution for another.

8 Effluent pretreatment methods and their effectiveness Plants were those using technology approaching BPCTCA, operating controls, and operational reliability. Pretreatment methods considered included such process modifications as may significantly reduce effluent loads, as well as conventional pretreatment processes.

o Plant facilities Plants that had all the facilities normally associated with the generation of electric power from steam. Typical facilities generally were plants which have all normal process steps carried out on-site.



### o Plant management philosophy Plants whose management insists upon effective equipment maintenance, good housekeeping practices, and efficient land use. Geographic location Factors such as land availability, rainfall, feed water quality, and differences instate and local standards were also considered.

o Characteristics of publicly-owned treatment works receiving power plant discharges Size, process employed, pollutants not susceptible totreatment, and any pollutants which would interferewith normal operation at a POTW were taken into consideration.

### DRAFT
GENERAL 

### DESCRIPTION OF THE 

### INDUSTRY The Steam ElectricPower Industry ismade up of 1273plants throughout the contiguous United States. Of these plants an estimated 7.7 percent or 98 plants discharge wastewaters to publicly-owned treatment works and are thus covered by the scope of this document. In this study 49 plants discharging to POTW's were contacted. Statistics for this section were estimated based on a truly random sampling of steam electric power plants contained in the "Environmental Assessment of Alternative Thermal Control Strategies for the ElectricPower Industry" by Michelle 

### M. Zarubica of the Cffice of Planning and Evaluation of the Environmental Protection Agency (18). Steam Electric plants discharging tothe POTW 

### tended 

### tobe smaller on the average than plants discharging to surface water. These plants averaged about 150 MW for a total capacity of 14,500 MW 

### which compares with 

### an average capacity and total generating capacity of about 400 MW and 506,700 MW 

### for the entireSteam Electric Industry. (See Tables 111-1 and 111-2). Of these plants, an estimated 72 percent are publicly-owned and 28 percent are investor owned. Most of the Steam Electric plants that discharge toPOTW's (68percent) use gas as their principal fuel compared to 31 percent for the entire industry Figures 111-1 and 111-2. Conversion of some plants from gas tooil is expected due to shortage of natural gas. Plants which dischargewastewaters toPOTW's tend tobe older than plants which discharge to surface waters. Tables 111-1 and 

### 111-2 show that 29 percent of the plants which discharge toPOTW's were built since 1960 as compared to 38 percent for the entire population. Also, plants built since 1960 represent 48 percent of the generating capacity of plants discharging toPOTW's compared 

### to78 percent forthe entire Steam Electric Industry. (See Figures 111-3 and III4). 

### Approximately 24 percent of a11 electrical gene'ration is nuclear powered but 

### no plants of this type were observed to discharge to the POTW. 

### Nonetheless, nuclear plants are included inthis document, since their chemical waste discharges are similar innature tothose discharged by 

### nonnuclear facilities (14). Steam Electric plants discharging toPOTW's are located in all regions of the country with somewhat higher than average concentrations in

### the Midwest and in

### California.

### DRAFT 

### Table 111-1. Total SteamElectricPlants inthe Contiguous United States

Total Number of Plants = 

### 1273 Total Number of Units = 

### 3011 Total Number of Megawatts=506,654 

### AverageStationSize = 

### 398 Percentage of Plants Confirmed as Discharging toMunicipal Sewers

# - by Number = 

### 7.7% 

### by Megawatts = 

### 2.9% Principal Percentageby Percentage by Unit Fuel Number Megawatts

Gas Oi1 Coal Nuclear

Percentage by Percentage by Unit Built 

### In Number MegawattsDRAFT Table 111-2. Steam Electric Plants Discharging to

Municipal Sewers intheContiguous UnitedStates

Total Number ofPlants = 

### 98 Total Number of Units = 277 Total Number ofMegawatts = 14504 Average StationSize = 148
Principal Percentage by Percentage by Unit Fuel Number Megawatts

Gas 

### Oi 1 Coal Nuc

### 1ear

Percentage by Percentage by UnitBuiltIn Number MegawattsDRAFT



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### GAS OVERALL PLANTS POPULATION DISCHARGING TO POTW'S

OIL COAL NUCLEAR PRINCIPAL FUEL Figure 111-1. Principal Fuel Use by Number 111-9

### PERCENTAGE OF 

### MEGAWATTS

--I
-2 N C3 P ul rn V 03 cD 0 0 0 0 0 0 0 0 0 0 0DRAFT

YEAR PLANT BUILT OVERALL DISCHARGING 

### POPULATION TO 

### POTW'S

Figure 111-3. Year of Construction by Number 111-11DRAFT

1910 1930 1940 1950 YEAR PLANT BUILT OVERALL PLANTS POPULATION DISCHARGING TO POTW'S

Figure 111-4. Year of Construction by Megawatt 111-12

### DRAFT 

### Process Description The "production" of electrical energy involves utilization and conversion of chemical or nuclear energy. Present day methods of utilizing energy of fossil fuels are based on a combustion process, followed by steam generation to convert the heat firstintomechanical energy and then toconvert themechanical energy into electrical energy. The maximum theoretical efficiency that can be obtained in

### converting heat towork islimited by the temperatures atwhich the heat can be absorbed by the steam and discarded to the environment. The upper temperature is limited by the temperature of the fuel bed and the structural strength and other aspects of the boiler. The lower temperature 

### is ideally the ambient temperature of the environment, although for practical purposes the reject temperature must be setby design significantly above the highest anticipated ambient temperature. Within 

### these temperatures, efficiencies are limited to about 40 percent regardless of any improvement to themachines employed. For any steam electric power generation scheme, therefore, a minimum of 60 

### percent of 

### the energy contained in the fuel must be rejected to the environment as waste heat (14). Fossil-fueled steam electricpower plants produce electric energy in a four-stage process, shown in Figure 111-5. 

### The firstoperation consists of the burning of the fuel in a boiler and the conversion of water into steam by the heat of combustion. The second operation consists of the conversion of thehigh-temperature, high-pressure steam intomechanical energy in a steam turbine. The steam leaving the turbine is condensed towater, transferring heat to the cooling medium, which isnormally water. The turbine output is conveyed mechanically to a generator, which converts the mechanical energy into electrical energy. The condensed steam is reintroduced intothe boiler to complete the cycle. The theoretical water-steam cycle employed in steam electric power plants isknown as the Rankine cycle. Actual cycles in

### power plants only approach the performance of the 

### Rankine cycle because of practical considerations. Thus, the heat absorption does not occur ata constant temperature, but 

### consists of heating of the liquid tothe boiling point, converting the liquid to vapor and superheating (heating above the saturation equilibrium temperature) the steam. Superheating isnecessary toprevent excess condensation in the turbines and results in

### an increase in

### cycyle efficienty. Reheating, the raising of the temperature above saturation of the partially expanded steam, is used toobtain improvements in efficiency and again toprevent excess condensation. Preheating

### Stearn 

# I

Fuel Inlet Boiler

Ash 

### outlet Electric Generator / 

### Power

Condenser

# r 7 -i 

### Cooling 

### Water In 

# +Cooling Water Out



## FIGURE 111-5 

### Process trow Diagram Steam 

### Electric Power 

### IndustryDRAFT of condensate to near temperatures with waste heat, isalso used for this purpose. Condensers cannot be designed to operate attheoretically optimum values because itwould require infinitely larger equipment. All ofthese divergences from the optimum theoretical conditions cause a decrease in efficiency and an increase inthe amount of heat rejected per unit of production. As a result, only a few of the larger and newer plants approach even the efficiencies possible under the ideal Rankine cycle. Also, as a result of second law limitations, modifications of the steam cycle of an existing plant are not likely to result insignificant reductions inheat rejection. Publicly-Owned Treatment Works (POTW) The POTW process isbroken down intothree basic treatment methods; primary, secondary, and tertiary. Primary treatment consists ofthe removal of coarse materials, settleable solids, oil and grease, floating material, and the reduction of biological oxygen demand. Most POTW's employ secondary treatment which converts soluble and colloidal organic material into settleable flocculant material that can be removed by sedimentation. Secondary treatment is of.ten enhanced by the addition of chemicals such as iron, aluminum salts, and polymeric flocculants. The use of terti3ry treatment processes are still uncommon and include the removal of chemical constituents not affected by primary and secondary treatment. Tertiary treatment is intended to remove chemicals which promote algae growth and unwanted aquatic vegetation. The POTW's receivingwastewaters from Steam Electric plants vary insize and treatment process employed. Plant size is determined by human population and industrial waste load of the area served. Those contacted inthis study ranged from 200,000 gpd to350,000,000 gpd insize. Treatment methods are determined by flow, waste load pollutant constituents, economics, energy and removal requirements, and plant age. There are a large number ofwastewater treatment processes inuse whose application isrelated both tothe characteristics of the waste and the degree of treatment required. These processes are shown inFigure 

### 111-6.P

### KIMARY 

# I SECONDARY

# / TERTIARY

# I

TREATMENT

, TREATMEIIT TREATMENT

Raw ~astc*ater - I 

### - 6 

# - Coaqulatlm Recetvlng and at en 

# - Sedlmntrttm



# - Synnfngand rrltRmovrl Neutrallzrtlon

Chemlcal Addlttonand tosgulrtlm Eqwllzrtlonand Storage Flltratlon 

# irli Controlledor 

# - Transported Otscharge

Trlckllng Fllter Absorptlm 

# Clq Ocean Otrposal

Aerated 

# P Appllcatlon ortrow*ater

Scecrge 

# -

Dlgestlonor 

# I - Vet Cmbustlon 1 Indmrrtlon I 

# - Stablllzatlon - Basin

Injection Thlckenlng Grrvltyor Flotrtlm 

# P-

Figure 111-6. Nastewater Treatment SequenceDRAFT SECTION 

### IV

INDUSTRY CATEGORIZATION

INTRODUCTION An evaluation of steam electric power industry stations discharging chemical wastes to publicly-owned treatment works (POTW's) was necessary to determine whether categorization and subcategorization would be he1pful inthe preparation of effluent pretreatment standards for this industry. From this evaluation, steam electric industry stations discharging to POTW's have been categorized according to individual industrial waste sources. Subcategorizationwas based on distinguishing factors within groups of plants. This method of categorization was also used and isdiscussed indetail inthe "Development Document for Effluent Limitation Guidelines and New Source Performance Standards for the Steam Electric Power Generating Category" October 1974 (18). Inthis study on pretreatment, however, low level radioactivewastes are not addressed. The basis of evaluation of plants inthe industry

### will be a combination ofthe appropriatewaste sources for a particular power plant. Guidelines 

### will be established for each waste source and can then be applied and utilized inthe manner of a building block concept. Inthe case of combined waste streams the appropriate guidelines 

### will be combined and weighted proportional to stream flow. The eight categories are presented inTable IV-1. The following were considered for industry categorization: age, size, fuel, geography, mode of operation, raw water quality, volume ofwater used, and pretreatment technology. 

### INDUSTRY CATEGORIZATION This industry has been categorized according to the individual industrial waste source. Marked differences were observed infuel type, boiler, pretreatment, and maintenance waste streams. These differences were the basis for subcategorization Although age, size, geography, mode of operation, and feed water hardness didvary greatly, these characteristics do not appear todirectly affect discharges. Statistical analyses discussed inSection I11and information found in Sections 

### V and VIIwere utilized inreaching these conclusions.

### DRAFT TABLE 

### IV-1



### I II.

IV.

VI.

VII.

VIII. Condenser Cooling System 

### A. Once-Through B. 

### Recirculating Boiler Water Pretreatment 

### A. Clarification B. 

### Softening C. 

### Ion Exchange D. 

### Evaporator E. 

### Fi

### 1 trati

### on F. 

### Other Treatment Boiler or PWR 

### Steam Generator 

### A. Blowdown Maintenance Cleaning 

### A. Boiler or PWR 

### Steam Generator Tubes B. 

### Boiler Fireside C. 

### Air Preheater D. 

### Misc. Small Equipment 

### E. Stack F. 

### Cooling Tower Basin Ash Handling A. 

### Oil-Fired Plants 1. flyash 

### 2. bottomash B. 

### Coal-Fired Plants 1. fly ash 

### 2. bottom ash Drainage 

### A. CoalPile B. 

### Contaminated Floor and Yard Drains Air 

### Pollution Control Devices A. 

### SO2 -

### Removal Miscellaneous Waste Streams A. 

### SanitaryWastes 

### B. Plant Laboratory and Sampling Systems C. 

### Intake Screen Backwash 

### D. Closed Cooling Water SystemsDRAFT FACTORS CONSIDERED

Power plants discharging tothe POTW's tend tobe older than surface water discharging plants. Insteam electric power plants, individual generation units are often installedat different times over a number ofyears. Newer units tend to be thermally more efficient then older plants and use less fuel per killowatt hour ofelectricity produced. Because offuel economics newer units generally tend to be used for base load production while other units are employed as peaking and cyclic units. Increased fuel efficiency may reduce wastewater loads such as ash transport water, wet scrubber water, etc. However, since age of units varies within even a single plant and no correlation can be drawn between processes, types of waste discharge, and plant age, age isnot regarded as a suitable basis for categorization. Size Although the size of steam electric power plants discharging to POTW's various significantly, the basic process iscommon toall facilities. Plant sizewas found to have little affect on quantity of treated effluent. Plants discharging to sanitary sewers tend to be smaller than power plants discharging to surface water. Therefore, size isrejected as criteria for categorization. Fuel Plants discharging to POTW's were identifiedas burning all three major fossil fuels, coal, oil, and gas. Incontrast to the entire population of steam electric plants inthe U.S. the majority of plants contacted inthis study use gas as fuel. Fuel-related wastes such as ash control transport water and coal piledrainage, can contribute towastewater discharge. The presence of sulfur inthe fuel may require scrubbers. Therefore, the affect of different fuels on certain processes and effluents isuseful for subcategorization. Geography Usually, steam power plants that discharge to the POTW's are located near orwithin municipal boundaries. Most ofthe plants contacted were, infact, situated indowntown areas. Plants discharging tothe sewers were located innearly all geographical regions of the United States. It isnoted that recent trends toward larger power generating stations, and the institutionof mine-mouth coal fed plants, have resulted inincreased rural plant construction and a reduced number ofmunicipally-1ocated plants.

### DRAFT 

### Since plant processes do not vary according to geography, all plants covered in

### this study are located in

### or near municipalities, geography isrejected as a criteria for categorization. Mode of Operation -- 

### Despite the fact that peaking and cyclic stations areolder and smaller than base load stations, many units of plants areoften utilized for extended periods for either purpose. Additionally, the basic operation isindependent of the type of serviceprovided. Therefore, mode of operation is rejected as a criteria for categorization. Raw Water Quality 

### -- After study of the affects of raw water quality on effluent discharge, quality of raw water was determined not to be a criteria forcategorization. Hardness would indeed affect operation by increasing the frequency of regeneration of the deionizer orrecharging the softener. The harder the raw water the more frequently the deionizer anion and cation must be regenerated and the hot lime and zeoliteunits have tobe recharged. Effects of raw water quality are included in

### the Boiler Water Pretreatment Category.

Volume 

### - of Water Used Water use varies greatly even among plants of approximately the same size. Itdepends primarily on the type of cooling system, the cost and quality of the water supply, and the extent towhich water conservation is practiced by individual plants. Because of wide variations in water consumption among individual plants of this industry, water use was not found to be acceptable criterion for categorization. Pretreatment Technology A 

### wastewater treatment system should be an integral part of a plant's water management program. It should be designed on the basis of the quality and quantity of the wastewater tobe treated and itsultimate disposal. Many plants in the industry discharge theirwastewater effluent tomunicipal sewer systems; others discharge only a portion. The extent of pretreatment varies widely from no pretreatment to integrated plants using complex systems such as equalization, neutralization, etc. No pattern was found for pretreatment technology in

### the industry, thus it 

### isnot a suitable basis for categorization.DRAFT SECTION 

### V WATER USE AND WASTE CHARACTERIZATION

INTRODUCTION Specific water uses and the waterborne wastes involved in steam electric plants discharging into pub1icly-owned treatment works (POTW) are described inthis section, along with other process waste materials. Process waters are characterized as raw waste loads from specific processes associated with the production of electricity. These are generallly expressed as grams per megawatt hour (MWH) ofelectricity generated. Water uses are given interms of liters per MWH, or as liters per day and waterborne waste loads in mg/liter or grams per MWH. The waste treatments used by both power plants and POTWs are described, and amounts and types of waterborne waste effluents after treatment are characterized. PRINCIPLES - OF OPERATION - OF STEAM ELECTRIC POWER PLANT Ina steam electric power plant, thermal energy, produced by rapid chemical combustion or nuclear fission reaction, isfirsttranformed into high pressure, high temperature steam, and then tomechanical energy through expansion of the steam ina turbine. The process can be divided into four stages. The first operation consists of fuel combustion inthe boiler furnace to produce high pressure, superheated steam. The steam isconveyed toa turbine where it isallowed togradually expand and cool inthe various turbine stages toconvert the thermal energy into electrical energy via mechanical energy. Inthe third operation the steam exiting from the final stage of the turbine iscondensed towater, transferring the heat to a cooling medium, which is normally water. Finally the condensed steam is reintroduced intoa boiler by a pump tocomplete the cycle. The power cycle components can be divided intothree principal units:

8 steam boiler 0 steam turbine 8 condenser

### DRAFT 

### Each of the cycle components provides an energy transfer and transformation function necessary to convert the heat energy into useful work. The following are descriptions of these three units. A 

### more extensive discussion on the principles of design and operation of steam electric power plants can be found elsewhere (14,16). Boi1 ers All boilers use the same basic design, that is, they are largemulti-tube heat exchangers surrounded by a furnace. The feedwater circulates within the tubes where itis heated, vaporized, and superheated producing steam to drive the steam turbine generators. Many different boiler arrangements are used. Oil and gas-fired boilers are simpler than coal-fired boilers because 1 iquid and gaseous fuels do not require the conveyers, pulverizers, and ash collection equipment necessary in coal-fired boilers. The boiler structuremay be either exposed or enclosed depending on local weather conditions, and is usually very large to accommodate the large tube surface areas required. Air 

### heaters, economizers, and other sections of the boiler are used to extract themaximum amount of heat from the combustion gases before they are discharged to the environment. This serves to increase the boilers efficiency: the ratio of heat converted to steam to the heat input 

### value of the burning fuels. Modern power boilers are able toachieve 85 

### to 90 percent efficiencies; the remaining 10 to 

### 15percent of the input heat value is discharged to the environment with the exhaust gases. This loss is referred to as the "stack loss." Figure V-1 shows a typical boiler for an oil-fired furnace. Steam Turbine The steam turbine consists of alternate rows of nozzles and blades on wheels. Each row of nozzles and its associated row of blades is called a turbine stage. As the steam expands through the nozzles, the pressure decreases and the velocity and specific volume increase. When the steam comes in contact with

### the blades a part of the momentum (kineticenergy) is transferred to the blades. The turbine shaft and generator are caused torotate and electricity isproduced.

### DRAFT


### There aremany different types of turbines and turbine arrangements in use. Most of the turbines are of the condensing type, discharging the steam from the last stage atbelow atmospheric pressure. The efficiency of a turbine 

### is highly sensitive to the exhaust pressure (back pressure). Turbines designed for once-through cooling systems are generally operated atlower back pressures than that designed for closed cooling systems. In most turbine arrangements a portion of the steam leaves the casing before the final stage. This type of turbine is referred toas extraction turbine. The extracted steam isused for feedwater heating purposes. In some turbines, a portion of the steam isextracted from intermediate stages, reheated in the boiler, and returned to the turbine or another turbine as a means of improving overall efficiency. Steam Condensation Steam leaving the final stage of the turbine is condensed intowater in

### the condenser. This is essentially a very large shell and tube heat exchanger designed towithstand the high vacuums associated with modern steam turbine power cycles. Heat 

### is transferred from the exhaust steam to an external cooling water system which may draw water from a surface or underground source, or from the cooling tower. There are two types of condensers; the single-pass and the two-pass condensers. If 

### all the water flows through the condenser tubes in one direction, itis call a single-pass condenser. If the water passes through one half of the tubes in one direction and the other half in

### the opposite direction, itisreferred to as a two-pass condenser. A 

### single~pass condenser usually requires a largerwater supply than a two-pass condenser and generally results in a lower temperature rise in

### the cooling water. Many condensers have divided water boxes so that half the condenser can be taken out of service forcleaning while the unit iskept running under reduced loads. Condensers are periodically cleaned mechanically as part of regular scheduled maintenance procedures. Some plants employ continuous on-line mechanical cleaning. Figure V-2 

### shows a typical single-pass condenser.

### STEAM 

### FROM TURBINE EXHAUST

CONDENSATE OUT COOLING WATE 

### (HOT) (COLD)



### F1GURE.V-2. Single-pass Condenser

### DRAFT

WATER 

### -- USE AND 

### WASTE CHARACTERIZATION - 

### BY CATEGORY 

### The results obtained on power plant wastes from visiting twenty-two plants, sampling eight, and reducing and analyzing the data do not differ substantially from those reported in the "Development Document for Effluent Limitations Guidelines and New Source Performance Standards for the Steam Electric Power Generating Point Source Category" (14). The majority of the water used in steam electric generating plants is for condenser cooling water. Lesser amounts are used for boiler makeup water, bearing cooling water, equipment cleaning, and othermiscellaneous purposes. Figure V-3 

### shows a typical Steam Electric process diagram with wastewater sources. Waste discharges can be classified under two categories: continuous discharges, and intermittent discharges. Wastes are produced on a continuous basis from the following (if applicable): cooling water systems, ash handling systems, wet-scrubber airpollution control systems, and boiler blowdowns. Waste discharges are produced intermittently by boiler water pretreatment operations such as ion exchange, filtration, clarification, and evaporation. Intermittent discharges are also produced during miscellaneous equipment cleaning operations and from sanitary and laboratory wastes. The following discussion is a categorization and description of water uses and waste discharges within typical generating plants. Much of the following has been summarized from Reference 14, which contains amore detailed discussion of water use and waste characterization. CONDENSER 

### COOLING WATER 

### All condenser cooling systems can be classified as (1) 

### oncethrough, or (2) 

### recirculating. Once-Through Systems In areas where large amounts of water are available from natural sources, the simplest method of condensing steam is 

### towithdraw water from the source, pass itthrough a condenser, and discharge itback into the same source ata higher temperature. Biocides such as chlorine or hypochlorites are usually added to systems of this type tominimize biological growth within the condenser. Once-through cooling systems have no waste discharges to POTWs,To Atm sphere 

# f

a 1 1 i Fly Ash -"em$=rls Uater Collection ---A

# ---- + and/or s02 Chemicals Scrubbing Device 

### I Wastewater To Raw @Treatment Mate Once Through Conb'n Air- Cooling Water ttng Cooltng Uater a

hemical s Makeup Waterd-+

q~unof f

## ]e Chemicals System Water

Floor and Yard Drains---.f~astewaterle Waste- 

# I~astes, intake Screen Backwash, Closed Cooling Water Systems Construe- 

# I tion. ~ctivity 

## I LEGEND: Liquid Flow 

# -------Gas 6 Steam Flow Chemicals a+-a-+ Optional Flow



### FIGURE V- 

## 3. Fossil-Fueled Steam Electric Power Plant-Typical Flow DiagramDRAFT Recirculating Systems 

### If sufficient water isnot available for a once-through system, condenser cooling water must be recirculatedwithin the plant. This isaccomplished by providing some sort of artificial cooling device, such as a pond or a cooling tower, to cool the coolingwater by evaporating a portion of it before recirculating itback tothe condenser. Ponds are used only where large areas of inexpensive land are available, since a large plantmay require over 1,000 acres of pond surface. Cooling towers may be either of the wet or dry types, and are used where sufficient land for ponds is unavailable or too expensive. Since all cooling devices (except dry cooling towers, which are rare) transfer the process waste heat to the atmosphere by evaporation additional water must be added to the system tomake up for these losses due toevaporation, driftand blowdown. Various chemicals are added to recirculating cooling systems to prevent biological growth incooling towers and to control scale accumulation and corrosion incondensers. These include biocides such as chlorine, hypochlorites, and organic chromates; and corrosion inhibitors such as organic phosphates, sodium phosphate, chromates, and zinc salts. Wastes that may be discharged to a POTW from recirculating cooling systems originate from cooling tower blowdown. Blowdown is

### the discharge from the cooling tower of a portion of water either constantly or intermittently to prevent the concentration buildup of salts that may form scale deposits within the condenser. This blowdown 

### will contain calcium, magnesium, and sodium cations incombination with carbonate, bicarbonate, sulfate, and chloride anions. Additionally, various amounts of the conditioning chemicals 

### will be present. The rate of blowdown can be estimated by the use of the following equation: (Ref. 1)

where: 

### B isthe blowdown rate; 

### Ev isevaporation rate; D is drift losses; and C isthe cycles of concentration defined as the ratioofthe concentration of a critical chemical species inthe blowdown to that inthe makeup water.

### DRAFT
The evaporation rate (Ev) from cooling towers averages about 1.5 percent of the cooling water flow for every 10°C 

### rise in cooling water temperature as the water passes through the condensers. The driftrate 

### (D) for new cooling towers is about 0.005 percent of the cooling water flow for mechanical draft towers, and about 0.002 percent for natural draft towers. Cycles of concentration (C) 

### is an expression of the buildup of any constitutent in the cooling water system from itsoriginal value in the makeup water. In practice, C 

### is usually between 4 and 6. 

### For very high qualitymakeup water, C 

### may be as high as 15, and for very salinewater, C 

### may be as low as 1.2-1.5. Figure V-4 shows typical once-through, and recirculating cooling system flow diagrams. Figures*V-5 

### and V-6 show two types of wet cooling towers. Water Use Once-Through Systems. Seven of the twenty-two plants surveyed use a once-through cooling system toremove the waste-heat from the process. The water usage in li-tersper 

### MWH atthe plant studied isgiven below: Plant No. Water Usage LiterIMWH

A 

### similar but 

### narrower range of water use for once-through condenser cooling of 1.105to 3.5~105 - 

### liters per MWH 

### was reported elsewhere (14). Plant No. 6421 has a higher than normal water usage because of intermittant operation.

### DRAFT

EXHAUST STEAM FROM TURBINE

EXHAUST STEAM FROM TURBINE a Y



### EVAPORATION SURFACE CONDENSER .WATER -b
* 

### DISCHARGE TO )SURFACE WATER

FIGURE V-4

# . Once-Through (top) and Recirculating (bottom) Cooling Systems 

## v CONDENSATE



# t I

1 

# . - f 

### COOL1NG TOWER CONDENSER 

### MAKEUP 

# I WATER CONDENSATE COOLING WATER

### DRAFT



# f SPRAY ELIMINATOR



# 0 WATER 

### 1N-z
m



### PUMP

FIGURE 

### V-5 

# . Diagram of Wet Forced-Air Cooling Tower

### DRAFT

AIR OUTLET

HOT W 

### DISTR

AIR INLET 

### ER BASI N



### FIGURE V-6 Natural-Draft Wet Cooling Tower (Counter-Flow)DRAFT Figure V-7 isa plot ofonce-through cooling water, corrected to

### fit normal distribution, against the cumulative percentages of involved plants expressed as probits (standard deviation plus five). The statistical parameters for the three modes of normal distribution examined are listed inTable V-1. The statistical approach used isdescribed inAppendix 

### A ofthis report. The results of the statistical analysis suggest an almost perfect fit ofthe corrected data tothe three-parameter modes of normal distribution. This is indicated by the coefficient of determination which measures the "goodness of fit" of the regression line. This value indicates that fitting of a least squares straight line accounts for almost 100 percent ofthe data variance. The water use data were also plottedagainst production rate todetermine the effect ofthe plant size on the quantity of water used. Figure V-8 shows a log-log diagram ofwater use for once-through condenser cooling as a function of production rate. Also shown inFigure V-8 are the regression lineand the 95 percent confidence limits. The statistical regression analysis coefficient expressed as logarithms are given be1ow. Statistical Parameters Value Slope -0.13 Intercept 6.14 Coefficient ofdetermination 0.11 Standard error of estimated water use on production rate 0.23 Standard error of intercept 0.17 Standard error of slope 0.94 The results ofthe statistical analysis suggest, at best, a poor correlation between water use for once-through cooling system and production rate. This is indicated by the value calculated for the coefficient of determination which indicates that a least squares regression line accounts for only 11 percent of the data variance. Although the overall trend suggests that the water use may decrease slightly with increasing production rate, this isnot substantiated by the statistical analysis.

### DRAFT

5.0 6.0 7.0 

### PROBITS



### FIGURE V-

### 7 

# . Normal Distribution Diagram for ; 

### Normalized Once-Through Usage DataTableV-1. STATISTICAL PARAMETERS FOR THE THREE MODES OF NORMAL DISTRIBUTION

# - ONCE-THROUGH CONDENSER COOLING

Statistical Parameter 

# \

Mean Variance 3rd Moment 4th Moment Coefficient of Skewness Coefficent of Kurtosis Correction Constant Slope Intercept Coefficient of Determination 

### 99%Confidence Limit Arithmetic
x~

## o4 Logarithmic 

### x1~4 3 Parameters Logarithmic 

### x1

## o4

### DRAFT



### Io5 Production Rate1

## o6 (MWH) FIGURE 

### V-8 Qnce-Through Cooling Water- 

### Use 

### vs. Annual Production RateDRAFT Recirculating Systems. Twelve of the 22 plants surveyed use a recirculating condenser cooling system to remove waste heat from the process. Waste heat is removed from the coolingwater by means of evaporation and blowdown. Water usage inliters per MWH at the plants studied isgiven below: Plant No. 9600 9650 9369 9371 8816 9585 8696 8135 8392 6293 7308 8875
Figure V-9 isa plotof recirculating condenser cooling water, corrected to fit normal distribution, against cumulative percent of involved plants expressed as probits (standard deviation plus five). The statistical parameters for the three modes of normal distribution examined are listed inTable V-2. The statistical approach used is described inAppendix 

### A 

### of this report. The coefficient of determination calculated for the three parameter mode of normal distribution, which measures "goodness of fit" of the regression lineto corrected data, indicates a good 

### fit to the n~rmal distribution. This value indicates that the least squares straight lineaccounts for 92 percent of the data variance. The water usage data was also plottedon log-log paper versus the production rateto determine the effect of the plant size on the quantity ofwater used. Figure V-10 shows the plotteddata, the regression line, and the 95 percent confidence limits. The statistical regression analysis coefficients expressed as logarithms are given below: Statistical Parameters Value Slope 0.06 Intercept 3.08 Coefficient of Determination 0.00 Standard error of estimated water use on production rate 0.77 Standard error of intercept 2.09 Standard error of slope 0.37

### DRAFT

3.0 4.O 5.0 6.0 7.O 

### PROBITS FIGURE

### V- 9

# . Norrnal Distribution Diagram forNormalized Cooling \dater Usage 

### Data

### Table

### V-2. 

### STATISTICAL PARAMETERS 

## FOR THE 

## THREE MODES OF NORMAL 

### DISTRIBUTION

# - RECIRCULATING CONDENSER COOLING

Mode of Normal

Statistical Parameter

Mean Variance 3rd Moment 4th Moment Skewness Kurtosis Slope Intercept Coefficient of Determination 

### 99%Confidence Limits Correction Factor Ari themtic Normal Logarithmic Normal 

### 3 Parameter Logarithmic

### DRAFT

95 

### Percent tonfidence Limit 

# --

# -- .--- -Be



### 0 

### Regression Line Q 0 

# e

95

### Percent Confidence Limit 

# ---3

# -- -----

1

## o5 1

### o6 Production Rate (MWH) FIGURE V- 

### 10

### ;Recirculating Cooling Water Use vs. 

### Annual Production RateDRAFT The results ofthe statistical analysis suggest no correlation at all between water use for recirculating condenser cooling and production rate. This is indicated by the low value calculated for the coefficient of determination. This analysis indicates that recirculating coolingwater use is independent of plant size. Raw Waste Load The raw wastes from the recirculating condenser cooling process include:

o Chemical additives to control growth organisms such as algae, fungi, and slimes;



### o Chemical additives to inhibit corrosion; and Concentrations of s o l i d s , metal1

### ic sa1ts, and acidic and alkaline ions due to evaporative loss. Initially, all ofthese wastes are waterborne, but some, such as suspended solids and metallic salts settle and must be removed from cooling tower basins periodically. Also, the settling ofmetallic salts cause scale formation on condenser tubes and must be removed periodically usually with an acid solution. The remainder of the raw wastes are either removed from the wastewater by treatment technologies, or are discharged to the sewer systems. Waterborne wastes are shown inTable V-3 for plants 8392 8135, 8696, and 7308. The waterborne raw waste values indicatethat the major components inrecirculating condenser cooling streams are dissolved and total solids, and chemical oxygen demand. Wastewater Treatment None ofthe plants using once-through condenser cooling systems discharge to POTW's. Eleven plants using recirculating condenser cooling systems discharge cooling tower blowdown to the POTW. None of the eleven plants discharging recirculating condenser coolingwastewaters to POTW's employed any treatment technologies. Wastes were discharged directly tothe POTW without treatment.Table V-3. RAW WASTE FLOWS AND LOADINGS CONDENSER-COOLING SYSTEMS

YASTFUATER SOURCE Cooling Tower Cooling Tower Cool4ng Tower Cool1ng Tower Cooling Tower Cooling Tower R- B 1 owdown Blowdown Blowdown Blowdown FLOU L/O~Y L/HWH L/uaY LIMWH L/Day LIMWH L/Day L/MWH LIUA~ 

# LKy I L'MWH

### . 0 745.81 53959.0 321.51 217788.9 18.03 (11 365.4 555.37 ' 1067370.0 1292.2 L/MWH PARAYETER nu/1 mg/l ~ng/ I

Cyanide (Total)

( Prosph2:e (Total)

-- l~otal Cissolved Solids

Total jdspended Solids

(1) Flow could not bemeasured.DRAFT
Effluent Waste Loads Information was not obtained on the composition of recirculating condenser cooling wastes after treatment since no plants performed any treatment before discharge to the POTW. Waterborne wastes present inthe recirculating condenser cooling discharge to the POTW can be found in Table V-3. WATER TREATMENT To compensate for steam losses through leakage and boiler blowdown, additional water must be added to the boiler. Particularly inhigh-pressure boilers; thiswater must be of extremely high quality, and must undergo extensive pretreatment. If the water istaken from a municipal supply, pretreatment may consist of dual media filtration, reverse osmosis filtration, and demineralization. Older, low-pressure steam plants may pretreat boiler makeup water solely with evaporators. Some steam electric plants treat water by clarification and softening followed by demineralization. 

### A more detailed description of those treatment schemes and their associated wastes follows. Clarification isa process for removing suspended solids and dissolved impurities. Chemical coagulants such as alum, ferrous sulfate, ferric sulfate, sodium aluminate, and polyelectrolytes are added to the water to aid the agglomeration of these impurities into larger, heavier particles. The particles are allowed to settle, and the clarified water isdrawn off and filtered. Softening may be performed prior to clarification to precipitate calcium and magnesium. Clarification and softeningwastes consist of sludges and filterwashes. Clarifier sludges consists of either alum or iron salts, and softening sludges consist of calcium carbonate and magnesium hydroxides. Filterwashes contain suspended solids either carried over from the clarifier or contained naturally inthe unclarified water. Demineralization (ion exchange) isa process that removes mineral salts by adsorption on a resin. Two types of resins exist: cationic (for the removal of cations), and anionic (for the removal of anions). These resins may be used separately, (one following the other), or they may be combined ina mixed-bed (demineralizer). After a period of use, ion exchange resins become saturatedwith adsorbed ions, and must be regenerated. Anionic resins are regenerated

### DRAFT 

### with sodium hydroxide solution followed by water rinse to remove residual alkalinity. The regeneration waste will have a high pH 

### and will contain the adsorbed anions, which are: sulfate, chloride, nitrate, phosphate, carbonate, and bicarbonate. Cationic resins are regenerated with sulfuric acid, and the regeneration waste from those units will have a low pH 

### and will contain calcium, magnesium, potassium, and sodium ions. Evaporation is simply a distillation process for the removal of dissolved impurities. Evaporators consist of a horizontal vessel heated by a waste heat source, which is

### usually exhaust steam from the turbines. Steam from the evaporation of water in the vessel is drawn off and condensed in an external condenser. To prevent a concentration buildup of saltswhich contribute to scaling problems within the vessel, a portion of the water is drawn off as blowdown intermittently. This blowdown has a high pH, and contains the same chemicals present in the raw water feed, which have been concentrated by a factor of three to five. Calcium carbonate and calcium sulfate precipitates may also be present in

### the blowdown if present in the water feed in sufficiently high concentrations. Phosphate is sometimes added tothe raw water feed to lessen the precipitation of calcium salts (14). Reverse osmosis is a process used by some plants to remove dissolved salts. The technique consists of forcing water through a semipermeable membrane under a pressure greater than the osmotic pressure of the dissolved salts. The salts are concentrated on one side of the membrane and the purified water is collected on the other. The concentrated salt solution (brine) is 

### discharged as a waste. Chemical Additions. After pretreatment, various chemicals are added 

### to the

### boiler makeup water. 

### These include hydrazine sulfite (toremove dissolved oxygen), sodium phosphate (toprevent scale formation by precipitating calcium and magnesium salts), and sodium hydroxide (to control pH). 

### Figure V-11 shows six (6)

### commonly used water treatment methods.

### DRAFT

Raw Water 

# I

Deionized ~ater -+


### Separated-Bed Ion

### Exchange Dembineralizer

Raw Water



### Mixed-Bed Ion Exchange Demineralizer 

# i Regulating

Valve

Conce trate (Wastewater) 

### Reverse Osmosis Membrane Filter

FIGURE 11. 

### Commonly Used Water Treatment Methods V-25

### DRAFT

Raw Water

Wastewater 

# hI rt"l + ISa1td-J 

# r+Asy-l

water Fi1tered 

# 1 -I++

Deion Blowdown Water Wastewater ized



### Coagulation-Filtration WaterTreatment Process

Treatment Chemicals 

### CLARIFIER 

# - I Feed



### Clarification Process Bloudown



### FIGURE 

### 11. Commonly Used Water Treatment Methods (Continued) V-26 

# -

EVAPORATOR Steam Aond. I i 

## # Evaporator Bloacow 

# f Evaporation ProcessDRAFT

Water Use Boiler Makeup Water. Sixteen of the twenty-two plants surveyed provided information on their boilermakeup water usage. The water use inliters per MWH atthe plants studied isgiven below. Plant No. Water Usage Liters/MWH

Figure V-12 isa plot ofthe boilermakeup water usage, corrected tofit normal distribution, against the cumulative percent of involved plants expressed as probits. The statistical approach used isdescribed inAppendix 

### A of this report. The coefficient ofdetermination calculated by the three parameter mode of normal distribution, which measures the "goodness of fit"of the regression lineto the correlated data, indicates an almost perfect fit to the normal distribution. The value indicates that the least squares straight lineaccounts for appoximately 97 percent ofthe data variance. (See Table V-4).

### DRAFT

5.0 6.0 7.0 

### PROBITS 

### FIGURE 

## V- 12

# . Normal Distribution Diagram for Normalized Boiler Makeup Water Usage Data

### Table 

### V-4. STATISTICAL PARAMETERS FOR THE THREE MODES OF NORMAL DISTRIBUTION-BOILER MAKEUP

Mode of Normal

,Statistical Parameters

-Mean Variance 3rd Moment 

### 4th Moment Skewness Kurtosis 

### $1ope Intercept Coefficient

### of Determination 

### 99%Confidence Limits Correction Factor Arithmetic

# I Logarithmic Normal Normal 

### 3 Parameter Logarithmic

### DRAFT

The water usage data was also plotted on log-log paper versus the production rate to determine the effect of 

### the plant sizeon the qtantity of water used. Figure V--13 shows the plotted dataithe regression line,and the 95 percent confidence limits. The statistical regression analysis coefficients expressed as logarithms are given be1ow: Statistical Parameters Value Slope -0.92 Intercept 7.1 Coefficient of Determination 0.47 Standard error of estimated water use on production rate 0.57 Standard error of intercept 1.45 Standard error of slope 0.26 The results of the statistical analyses suggest a fair correlation between water use for boiler makeup and production rate. This isindicated by the value calculated for the ccefficient of determination which indicates that the least squares regression line accounts for approximately 50 percent of the data variance. Demineralizx. Thirteen of the twenty-two plants surveyed presented information on their demineralizer system water usage. The water usage in

### liters per MWH 

### atthe plants studied isgiven below: PlantNo. Water Usage,Liters/MWH 65.75 17.51 27.55



### 3.24~102 

### - 4.56 18.38 13.46

4.22~102 7.1 

### 9.01 11.35 39.23

5.69

### 1

## o5 1 

## o6 Production Rate (MWH) 

### FIGURE 

### V-13

# . Boiler Makeup Water Use 

### vs. Annual Production Rate

### DRAFT Figure V-14 isa plot of the demineralizer water use, corrected to fitnormal distribution, against the cumulative percent of involved plants expressed as probits. The statistical parameters for the three modes of normal distribution examined are listed in Table V-5. The statistical approach used is described in Appendix A 

### of this report. The coefficient of determination calculated by the three parameters mode of normal distribution, which measures the "goodness of fit" of the regression line to the corrected data, indicates an almost perfect fitto normal distribution. This value indicates that the least squares straight line accounts for 97 percent of the data variance. The water usage data was also plotted on log-log paper versus the production rate to determine the effect of plant sizeon the quantity of water used. Figure V-15 shows the plotted data, the regression line, and the 90 percent confidence 1 imits. The statistical regression coefficients expressed as logarithms are given below.
Statistical Parameters Value Slope 0.03 Intercept 1.52 Coefficient of Determination 0.00 

### Standard error of estimated

water use on production rate 0.65 Standard error of 

### intercept 

### 1.76 Standard error of slope 0.31
The results of the statistical analysis suggest no correlation at all between water use for the demineralizer system and the production rate. This is indicated by the value calculated for the coefficient of determination which indicates that a least squares regression line accounts for zero percent of the data variance. From this analysis, itmay be assumed that demineralizer water use is independent of plant size.

### DRAFT

3.0 4.0 5.0 

### 6.0 7.0 PROBITS 

### FIGURE V-14. 

### Normal Distribution Diagram for Normalized Ion Exchange Water Usage DataTABLE V-5. STATISTICAL PARAMETERS FOR THE THREE MODES OF NORMAL DISTRIBUTION 

### - DEMINERALIZER

Mean Variance 3rd Moment 4th Moment Skewness Kurtosis Slope Intercept Coefficient of Determinatio! 99%Confidence Limits Correction FactorDRAFT



### 90 Percent Confidence Limit 

# ---------a,------------

Regression Line 

# a 0

90 Percent Confidence Limit

# ---- 

# ---------------

1



## o4 1 

## o5 1 

## o6 lo7 Production Rate (MWH) FIGURE 

### V-15. Demineralizer Water Usage vs. Annual Production Rate



### v-35

### DRAFT 

### Raw Waste Load The raw wastes from thewater treatment process include:

o 

### Mineral salts, suspended solids and other constituents removed from the raw water supply. Chemicals used by thewater treatment units. Of the twenty-two plants visited, three use hot lime-soda ash softening and zeolite ion exchange, two use hot lime-soda ash softening, filtration, and zeolite ion exchange, two use reverse osmosis and deionization, twelve use cation-anion ion exchange, one uses deionization and evaporation, one uses hot lime-soda ash softening, zeolite ion exchange and evaporation, and one uses deionization and evaporation. Solidwastes arenot generated in

### large quantitites during thewater treatment process. The major source of solid wastes arecalcium carbonate and magnesium hydroxide from the lime-soda ash softening processes. Waterborne wastes forplants in

### terms of grams per MWH 

### are given in 

### Table V-6. 

### Wastewater Treatment Fifteen plants dischargewater treatment waste streams to POTW's. 

### Five of these plants practice some 

### type of pretreatment before discharge. Plant 6293 

### uses lime settling; plant 9369 

### uses equalization and neutralization; plant 7308 

### uses equalization, neutralization, and settling; and plant 8696 

### uses equalization, settling, and oil skimming. Effluent Waste Loads Table V-7 

### shows the composition of pretreated wastewater discharge to the POTW 

### in terms of concentration and waste loads forplant 6293. 

### BOILER BLOWDOWN 

### To prevent the accumulation of calcium and magnesium salts on the internal boiler surfaces, phosphates are usually added toprecipitatethe salts. The precipitate isremoved continuously orintermittentlyby withdrawing a portion of the boiler water as blowdown. Blowdown wastes have a high

### Table '1-6. 

### RAW WASTE FLOWS AND LOADINGS

# - WATER TREATMENT

(I) Flow could not be measured. 0 ;O D 7 --I PLANT 10. ;ASTEYLT~~SO,,~CE iLou 

# z2"'8.13

CR COO5 Bromide (8romrte) COO Chromium ~hramiua'6 topper Cyanide (Total) Iron LllckCl 011 arid Grease Phosphate (Total) lotrlOissolved Sollds

lotal Suspended Soll#s lolrl Sollds Surfrctrntr , tlnc 6187'~ 6387 LIme Softener Zeollte (slug /Day Tho W/'

10 4

561 0.1 0.001 0.12 0.005 0.44 0.25 1.O

22980

44 23024 

## ------ 0.09 Backwash

.dY 18.7 "911

1.8
--- ZOO 0.11 0.004 0.15 0.014 10 4 0.09 10

1004

9440 10444

-

--- 0.32 8392 Oemineallzer Backwash

2:":g/MUH 2.62

141.55

0.02 0.001 0.03 0,0011 0.11 0.06

5798.6

11.1 5809.7

0.02 

### % glHUH 0.08
----- 9.53 0.005

0.007 0.0006 0.49 0.004

47.88

450.2 98.08

0.015 (process

Nb/:

1.0 1.02 2 0 0.02 0.005 0.02 0.005 0 07 0.03 1.0 0.05 174

1 0 174 - 0.011 -- 0.02 6387 8231 

## I fvaporator Olowdown Oalnersllzer Reopneration water)

9:M)Uh

.

- -

- 6293 1f.e Softener 9650 

# - CdinedCeminerallzer

Fffl~.rnr L/Da# LI'YV 8231 Demlnerallzer Bactwash 8135 Oemineallzer L/O4y m911 48.0 ...- 37.2 0.09 0.006 0.06 0.005 9.0 0.07 1.0 

### -.- 188

1780 1968 0.010

- 0.12 5103 75 roll ------

----a- ------ 

### - 0 2 0 01 0.59
.----- 9.46 0.2 10
------ ------ 16.7



### -------. -------- 

# --

0.21 

### tii;i D9/l

15.2

76.0 0.02 OW kl73.8 n411 ----- ----- ----- 0.02 0.005 0 02

----- 0.03 0 03 8.2 --

---- ------ 6.8

-

### .---- 0.38 0.01 Effluent :{:;I5 "911

1.0 1.19
9 8. 0.02 0.002 0.02 0.005 0.02 0.03 1.0 ---- 0.16



### ---- 0.16 

### ---- ---- L/WH 9/,4~n 3.27
-...- 2.53 0.006

0.004

0.6 0.004

---- 12.8

121.27 134.08

0.001

- 0.008 61 a C/HL ------

------

------ 0.31 0 Ci.r o 03 

### ------. 0 5e 0 01



## . --

.. -. --.---

. -------

I.03

-------

------. 0 01 11:!:27$;$

(1M.H 1.72

8.62 LIIWH 2.46

gIWH -----

-----
-----

----- -----

-----
------

------ ------ 0.02 ------

------ 0.016



### --.--- 0,0009 ------ wjll -- -----
----- 0.07 

### 'in:! g/UUH 0.003 0.004 0.03

----- 

### ----- 

### ----- ----- ----- 

### ----- ----- 0.05 174

1.0 114 0.011 0.02 0.005 0.02 0.006 0.38 0.03 1.0 6.20 2228

9 3

2321

0.11 21.73 L'INH g/WH -.... ----- ----- 0.001 0,0001
------

------ 0.02 0 003 0.28 .--.. ----- 0.63



### -.--. ----- 

## ---- 0.001 0.050' o 002 0.OOOt 0.043

0.7 252.9 105.6

263.5

0.01 0.006 0.02

----- 1.26 0 14 13.2



### ....-

-----

31


### -.--- -.---
0.06

### DRAFT

TableV-6. 

### RAW WASTE FLOWS AND LOADINGS

# - WATER TREATMENT (CONTINUED)

IPLANT NO. 

# 1 8696 (7308 

# 1 7308 

# WASTEWATER SOURCE

# 1 cation Demin- Evaporator era1i zer Bl owdown 

# ISof~~~~~t~ackw\~eqeneration L/Day L/MWH PARAMETER \11355(2) 0.94 mq/l q/MWH BOD, 6.0 0.005 Bromide (Bromate)

I I Copper 

# 1 1.3 o.ooi72.61 0.13 Ncg 

# 1 LIDay L/MWH

(1) (1) mg/l g/MWH 5.16 

### (1)

Chromium (Total) ~hromi um+6 Wash L/Day L/MWH 4920.5(2) 0.29 mg/l 9/MWH

27 0.008 0.03 0.00002



### 10i 1 and Grease 

## ]<1 .0 11.9 

# 1 1.4 0.0004 

# 1 0.07 0.00006 0.008 Neg.

Cyanide (Total) Iron

l~hosphate (Total)

# / 14.0 0.013 112.6 

# 1 0.5 0.0001 

# 1 ---- 0.07 

### Ne!3

0.08 0.036

c0.005

1.02 0.009 CO.02 

# ----- 0.016 Neg

Total Dissolved Solids 0.028 0.22

Total Suspended



### . Solids Total Solids

(1) Flow could not be measured (2)Discharges 1 hour per day (0.005 

# --

# --- 40.57 

### -----

3960 3.72

Zinc 3 0 0.03 3990 3.75 I



# . - 0.03 0.000022532.66

14.5 2547.16 28066 8.21

18.4 Oi005 

# - 28084.4 8.22

0.44 0.08 0.00002Table 

### V-7. EFFLUENT FLOWS AND LOADINGS 

# - WATER TREATMENT

PLANT NO. 

### 1 6293 

### I 8696 

### 1 8237

I I I I I I Bromide (Bromate) 

## I ----- 

### I 

### ----- ---- I WASTEWATER SOURCE FLOW PARAMETER

I I I 1 I I Iron 

## I 1.23 

## 1 0.08 

## I 3.0 

## I 0.01 10.85 ( 0.020 I 1 Lime Softener

# s Effluent

COO Chromiurn Chromium+6 Copper Cyanide (Total) L/W L/MWH 16351.7 68.13

5.9 0.02

Nickel 0.03

P Oil and Grease 1.O Phos~hate (Total) 

### ------- LIDay L/MWH 54504 4.57



### .-, I 1 1 I I I Effluent LIOay L/MWH 15518.5 14.85 mg/l 

### I 9fRWH 

### 1 mgll 

### I 9/MWH

0.4 0.001

Total Dissolved Solids

### I 152.0

Total Suspended Solids Total Solids Surfactants Zinc mg/l 

### I g/c

0.001 0.13


### ------- I I I

10.35 

## I 954 

### I 0.026 0.02 0.005



### --

### --

# -

-----
------

245.0 397.O 

### -- 0.011 0.2 

### ------ 0.0007 I I

0.001 0.001


### ----- 0.0001 81.O

0.05 40. 005

16.69 27.04

0.0001 0.0001 0.09 9.36



### ------- (0.03

1.80



### ---- 0.88 (0.005 0.36 0.002



### -------

-------. 0.008

-------.

219 1173 

## ------

0.18 

### ------ 

## ------ 

### - 0.05 0.007

0.98 5-26


### ------- 0.0008 25.02 0.35


### -------

------- 0.04 

### -----

### --

------- 0.0005DRAFT

pH and a high dissolved solids concentration. Blowdown from boilers treatedwith phosphate 

### will contain hydroxide alkalinity and phosphate, and blowdown from boilers treated with hydrazine 

### will contain ammonia. Raw Waste Load The raw wastes from boiler blowdown include: Chemical additives to remove oxygen;


### e Chemical additives to prevent scale or inhibitcorrosion; and

e Concentrations of dissolved solids and other constitutents present inthe boiler feedwater. Boiler blowdown does not generate large quantities of solidwaste. Sludge, which consists of precipitated calcium and magnesium salts, ismaintained ina fluid form and removed by the blowdown. Waterborne wastes for two plants interms of grams per MWH are given inTable V-8. The waterborne raw waste values indicate that the major components by weight inboiler blowdown streams are dissolved solids, chemical oxygen demand, and total phosphates. Wastewater Treatment irteen plants discharge boiler blowdown to POTW's, of ich, three practicesome type of pretreatment. Plant 9369 es equalization and neutralization, plant 7116 uses ualization, neutralization and settlingand plant 7308 es equalization, neutralization and oil skimming. EffluentWaste Loads Informationwas not available on treated waste streams from boi1 er blowdown.

### Table V- 

### 8 

# . RAW WASTE FLOWS AND LOADINGS 

### - BOILER BLOWDOWN

PLANT NO. 6293 8392 8231 9650 WASTEWATER SOURCE Boiler Blowdown Boi1er Blowdown Boiler Blowdown Boiler Blowdown

I I I : 1 FLOW L/DAY L/MWH- L/OAY LIMWH L/DAY LIMWH L/DAY 1 L/MWH 17030.4 70.96 1665.4 5.20 5715 5.47- 

### 0~ 1 PARAMETER 

## 9/MWH mg/l mg/1 g/MWH mg/1 g/MWH mg/l

I I I

Bromide (Bromate) 

## ---- 

## ------ ----- ---- ---

# - ------ ----me 

## ----- COD 157.0 11.1 2.0 

### ---- ----- 

## ------ ------ 

# ----- I I I I I I I I Chromium (Total) 

# 1 0.02 

## -------

# 1 0.02 

# 1 0.0001

# 1 0.02 

## -----
I 1 I I Chrcmium+6 

# I 0.007 Neg

### . 0.005 

## -----

I I I Copper 

# 1 -0.19 

### ( 0.01 

# 1 0.06 I I Cyanide (Total) 0.005 

## ------- 0.014 Neg

### . ----- --

# ---- 

## ------ ------ Iron 1.4 0.1 0.08 0.0004 0.03 0.03 

## ------ Nickel 0.03 

## ------ 0.03 

## ------ 0.03 

## ------ 0.03 

## ------ Oil and Grease 2.2 0.15 1.O 

## ------ 14.8 0.08 5.3 

## ------

- - - Phosphate (Total) 18.7 1.32 19.8 0.1 0.05 Total Dissolved Solids 1405.0 99.7 118.0 0.61 

## ----- ------ 

## ----- 

## ------

Total Suspended Solids 2.7 0.19 6.9 0.036 31 0.17 8.3 

## ------ Total Solids 1407.7 99.9 125.0 0.65 

## ----- 

# _______ ----- 

# ------ Surfactants 

### ------ 

## ----- ----- 

## ------ ----- ------- ------ -----

# -
Zinc 0.05 0.003 0.02 0.0001 0.01 

## ------- 0.02 Neg

## .

-- - -- - - (1) Flow could not be measured.

### DRAFT


### MAINTENANCE CLEANING Boiler Tubes. Boiler tubes must be cleaned occasionally toremove accumulations of scale. A 

### multitude of cleaning mixtures are used to accomplish this purpose with a minimum of effort. These include: alkaline cleaning mixtures with oxidizing agents for copper removal, acid cleaning mixtures, alkaline chelating rinses, organic solvents, and proprietary solvents. Wastes from these cleaning operations will contain iron, copper, hardness, and phosphates. In addition to these constituents, wastes from a1kaline cleaning mixtures will contain ammonium 

### ions, oxidizing agents, and high alkalinity; wastes from acid cleaning mixtures will contain fluorides, high acidity, and organic compounds; wastes from alkaline chelating rinses will contain high alkalinity and organic compounds; and wastes from most proprietary processes will be alkaline and will contain organic and ammonium compounds. Boiler Fireside Cleaning. The fireside surface of boiler tubes collects airborne dust, fuel ash, and corrosion products. These materials are removed from time to time with high-pressure hoses. Alkaline chemicals may be used tomake the cleaning more effective. Wastes from this operation will be more or less acidic depending on the sulfur content of the fuel, and will contain hardness, suspended solids, and some metals. Air Preheater Cleaning. Air preheaters are used to heat ambient airthat isused for combustion, and collect soot and fly ash. High-pressure hoses are used to remove these materials. The wastes from this operation will be more or less acidic, depending on the sulfur content of the fuel, and will contain suspended solids, magnesium salts, iron, copper, nickel, and 

### chromium. Vanadium may also be present if the plant isoil-fired. Stack Cleaning. High pressure water isused toclean fly ash and soot from stacks. The frequency that this cleaning is required is dictated by the-fossil fuel used. Wastes from this operation may contain suspended solids, metals, oil, and high or low pH 

### values.DRAFT

Cooling Tower Basin Cleaning. Deposits of carbonates on the bottoms of cooling towers and growth of algae on coolingtowers are removedoccasionally with water. The wastes contain suspended solids as a primary pollutant. Miscellaneous Small Equipment. Occasional cleaning of plant equipment such as condensate coolers, hydrogen coolers, aircompressor coolers, and stator oil coolers isperformed. Detergents, wetting agents, and hydrochloric acid are often used during cleaning. Wastes from these operations will contain suspended solids, metals, oil, and low or high 

### pH. Raw Waste Load The raw wastes from maintenance cleaning consist ofthe cleaning solution and the material removed from the equipment. Boiler fireside, air preheater, and boiler tube cleaning account for most ofthe wastewater generated in maintenance cleaning. No plants were performing maintenance cleaning during the time of our visitation and sampling. Typical waterborne wastes are shown inTable V-9 for wastewaters from air preheaterboiler fireside, and tube cleaning. This informationwas obtained from Reference 14. Information was not available on cooling tower basin and stack cleaning wastewaters. The major components by weight inthe three cleaning waste streams are dissolved solids, hardness, metals, chlorides and sulfates. Water Use At infrequent intervals, certain power plantscomponents such as condensate coolers

### , oi1 coolers

## , compressors, boi1 ers

### , etc. are chemically cleaned with a solution of hydrochloric acid, or a detergent. Typical flow rates are summarized on page V-45 (14).

### DRAFT

Table

### V-9. RAW WASTE FLOWS AND LOADINGS 

### - MAINTENANCE CLEANING 

# I No. ofPlants

Wastewater Source Cleaning Frequency 

## 1Parameter (Kg) 

# IBromide (Bromate)

C0D Chromium (Total) Chromium

Cyanide (Total) 

# IIron 

# I Nickel 

# IOil and Grease 

# IPhosphate (Total)

Total Dissolved Solids Total Suspended Solids Total Solids Surfactants 

# IZinc 7 plants 

## I 2 plants 

## I 7 olants Air Preheater Boiler Fireside 

### 1 Boiler Tubes 

### I IDRAFT

Waste Waste Typical Flow Stream Flow or Volume Frequency or Volume Chemical Cleaning BoilerTubes 3-5 Boiler Once/7 Months- 1 boiler per Volumes once/100 mos. 1-2 hours Boiler Fire- 24-720~10~~al 2-8/yr 300,000 Gal side 3 

### Air Preheater 43-600x10 gal 4-12/yr 200,000 Gal

Wastewater Treatment Four plants discharge maintenance cleaning wastewaters to POTW's of which two utilizesome type of pretreatment Plant 6387 uses settling and plant 8696 uses dilution, equalization, settling and oil skimming. Three plants have outside contractors haul away boiler cleaning wastes. Effluent Waste Loads Informationwas not obtained on the composition of maintenance cleaning wastes after treatment.

### DRAFT



### ASH-HANDLING SYSTEMS One of the products of the combustion of coal and oil in electric utilities is ash. Ash which falls to the bottom of the furnace is called bottom ash; ash which leaves the furnace with 

### the flue gas is called fly ash. Fly ash is usually collected from coal-fired units with electrostatic precipitators and from large oil-fired units with cyclones. The function of ash-handling systems is to remove accumulated bottom ash and fly ash. Two types of ash-handling systems exist: dry systems and wet systems. Dry systems use pneumatic conveyance devices for the transport of ash and are not a source of liquid wastes.. Wet systems use water for the transport of ash, transporting the ash-water slurry through sluices and in many cases, discharging itinto a settling pond orbasin. Wet systems are either of the open type or the closed type. Open systems discharge supernatant from the settling basin into either a receiving water or a POTW. 

### Closed streams recycle the supernatent back to the ash-transporting sluice for reuse. Figure V-16 shows a flow diagram for recirculating bottom ash system. Periods of extended rainfall may cause problems with closed systems, since some water may have to be withdrawn from the settling basin and discharged. Similarly, extended periods of dryness may evaporate excessive amounts of water from the settling basin, requiring the addition of supplementary water to the system. Ash pond overflows from coal-fired plants contain a wide variety of constitents whose concentrations can vary widely depending on the particular coal used. Generally, the overflows contain high levels of dissolved solids, suspended solids, hardness, sulfate, sodium, magnesium, chloride, and alkalinity. Other trace metals originally present in the coal may also be present. Ash is produc.ed in oil-fired plants in very small quanitities. Ithas been found that oil ash does not settle as well as coal ash. In some utilities, the oil fly ash is recycled into the furnace, increasing efficiency and eliminating the disposal problem. Ash pond overflows from o i l - f i r e d plants have some of the same characteristics as those from coalfired plants, and may additionally contain high concentrations of vanadium. Table V-10 contains an itemization of the types of ash handling systems used by the plants that were visited.

### DRAFT

EVAPORATION EVAPUKAl LUN LU33 LU33 MHKL-UI-'



### ASH HANDLING SYSTEM

ASH SLUDGE FOR DISPOSAL RAINFALL



# .

FIGURE 

### V-16. Flow Diagram for Recirculating Bottom Ash System 

## +

RECYC 

# . OVERFLO 

### SETTLING POND

### Table V-10. ASH DISPOSAL METHODS

r

### PLANT NO.

9600 

### 9650

Key: (1) Soot blowing steam (2) 

### Fireside washing (3) Dry collection system from electrostatic and/or mechanical precipitators, ash then hauled to landfi11.. 

### (4) Dry collection sy-stem-ash 

### landfilled. (5) 

### Air wash in stack to control fly ash-discharges to POTW (6) 

### Wet collection system with settling sump-(overflow from 

### sump'goes to 

### POTW) 

### (7) Vacuum system using steam, ash landfilled, condensate from steam goes 

### toPOTW. (8) Wet system discharging to surface water. : 

### TYPE OF 

### PLANT

< I P O3 

### ASH DISPOSAL SYSTEM FLY ASH 

### BOTTOM 

### AS'H

. 

### - Oil and Gas Oil and Gas None Required 

### 1 2 

### -9359 ,9371 7485 ,881 6 ,9585 .7116 -8696 ,8135 ,9163

6387 -8352

6293 ,7 

### 308 ,8875 7968 

### 6421 16214 6294 

### Oil and 

### Gas Oil and 

### Gas Coal 

### , Oi1, 

### and Gas Oil and Gas Gas Oil and Gas Oil and Gas Oil and 

### Gas Coal Coal Gas Coal Oi1 

### Oil and 

### Gas Coal and 

### Gas

Oil and Gas Coa1 

### Coal and Gas 3 4 

### 3 2 

### 3 4 

### 1 2 None Required 3 4 

### 3 2 

### None Required 3,5 4



### 3 6 

### None Resuired 3 7 

### None Required 1 2 

### 3 

### 7 None Required 8 8 3 8

### DRAFT Mater

# 5 Of the twenty-two plants visited inthis study, only four used water to convey fly 

### and bottom ash to ash ponds; the remaining plants use dry ash transport systems. Of

### the four plants utilizingwet systems, all were coal-fired. Plant 9163 uses 2.65~102liters per 

### MWH, the only plant usingwater for flyashtransport. The other three plants 6387, 8356, and 6294, respectively use 43.09, 3.61~102 - 

### and 11.39 liters per MWH 

### for bottom ash transport. Raw Waste Load 

# - Oil-Fired Plants. Fuel oils contain only about one percent 

### of the amount of ash commonly found incoal, consequently, ash disposal problems from oil-fired plants are minimal. FlyAsh. Many ofthe oil-fired plants visited used mechanical cyclones to remove fly 

### ash from the flue gases. 

### A dry system isusually used to remove the collected ash. Inother plants, no flyash collection system isnecessary because ofthe low ash content of the oil used. Inthese plants, most of the ash inthe flue gases collects on the interior surfaces of the boiler and is removed by high pressure steam (soot blowing steam), and passes through the stack tothe atmosphere. Bottom

## 3. Some ofthe oil-fired plants visited needed only occasional fireside washing to remove bottom ash, other plants had dry collection systems that removed ash for land disposal. Coal-Fired Plants. The amount of ash produced by coalfired plants ismuch greater than that produced by 

### oilfired plants, requiringthe use of m o r e ' c o m p l e x ash-hand1ing systems. FlyAsh. Electrostatic precipitators or mechanical cyclones are used in

### most ofthe coal-fired plants tocollect fly 

### ash. The collection systems from these units are usually 

### dry, and the final ash disposal ison land. One plant, 

### No. 9163, used an additional system for fly 

### ash control, consisting of a wash inthe stack that discharged excess flyash toa POTW.

### DRAFT

Bottom Ash. Methods for disposing of bottom ash varied widely among the coal-fired plants that were visited. Plants 7485 and 9163 used dry collection systems for the land disposal of bottom ash. Plant 6387 was the only plant visited that used awet transport system in combination with a settling sump. Two plants No. 6293 and 7628 used a vacuum collection system with steam. One plant, No. 6294, used a wet collection system discharging to surface water. Plant No. 6214 mixed both bottom ash and fly ash with once-through cooling water. Table V-11 shows raw waste loading for two plants, 6293 and 6387. Wastewater Treatment Oil-Fired Plants. Because of the small quantities of ash produced by oil-fired plants, none of the visited plants had ash treatment systems. Coal-Fired Plants. Only one plant, No. 6387, used a settling basin in conjunction with awet ash transport system.- Most of the other coal-fired plants had 

### no need for an ash treatment system, since these plants used dry collection systems, followed by land disposal. Effluent Waste Loads Oil-Fired Plants. Effluents from ash cleaning of oilfired plants are present for those plants which used fireside cleaning for ash removal. Coal-Fired Plants. Plant No. 6387 is the only visited plant that discharqed a siqnificant amount of waste from an ash handling-system 

### to a 

### POTW. The discharge consists of the overflow from the ash settling sump. Treated effluent is shown in Table V-12. DRAINAGE 

### Floor and Yard Drains. Floor and yard drains collect wastes -- -

### - from leakage and numerous cleaning operations, and may discharge 

### to

### a POTW. The waste will contain dust, fly ash, coal dust from coal-fired plants, oils, and detergents.DRAFT

Table V-11 

# . RAW WASTE FLOWS AND LOADINGS 

# - ASH HANDLING

PLANT NO. 

# I 6293 

# I 6387 WASTEWATER SOURCE 

# I Ash Transport 

# I Ash Transport 

# I

Bromide (Bromate) COD Chromi

### urn

Oil and Grease 

# 1 1.0 

# 1 ---- 

# I 1

### .O 

# I ----- 

# I Copper Cyanide (Total) Iron Nickel 

# -

# -- 1235.0 0.37

0.16 0.005 76.0

0.24

Phosphate (Total) Total Dissolved 

# ---- 140.23 0.04

0.018 0.0005 8.62 0.03

3.4 388.0 

# --- 290.0 0.12 

## ----- 36.58

0.015



# .

0.20 0.112 6.2 0.03

0.38 44.05

. Solids -0.025 0.014 0.78 0.003

129.90 173.95 Total Suspended

Solids Total Solids Surfactants 

# ------ 

# ------ ------ Zinc 

### 0.55 0.06 0.08 0.02 1894.0

1144.0 1532:o



## -------

# - 0.01 - - - --- --- - - --



## ------ 238.95

1651.O 3545.0 208.30 447.26DRAFT

PLANT NO.

FLOW 

# I PARAMETER 

# I

Bromide (Rromate) 

# k------I- Settled ash transport condensate L/MWH 45420

### .O 126.16

Chromiurn Chromium+G 

# - Copper Cyanide (Total

### ) 

# I Nickel 

# I

Oil

### and Grease Phosphate (Total) 

# ITotal Dissolved Solids 

# I

Total Suspended Solids 

# 1Total Solids 

# I

I Surfactants 

# I

Zinc 

# IDRAFT

Coal Pile. The storage of large quantities of coal 

### -- isnecessary for coal-fired plants to insure continuous operation and tosimplify delivery by the supplier. A 90-day supply isnormally maintained. Coal storage piles are oftwo types: active and storage. Active piles are used continuously and are subject to infiltrationby rainwater. Storage piles are used for the long-term storage of coal, and are usually protected from rainfall with some sort of seal, which can be either a layer of asphalt or a layer of fine coal dust covered with lump coal. Waste discharges from coal storage piles are the product of drainage from rainfall. This drainage can be either acidic or alkaline. Acid drainage isthe result of the reaction of pyrite (FeS2) withwater and oxygen, which produces ironsulfate and sulfuric acid. This type of drainage ishighly acidic, has a low pH, and contains a large amount of ferrous iron and some aluminum. Alkaline drainage occurs when acid drainage isneutralized by alkaline material present inthe coal, or when the coal has a low pyritecontent. Alkaline drainage ischaracterized by a pH of 6.5 to7.5 or greater, littleacidity, and significant concentrations of ferrous iron. 

### Ifthe ferrous ironconcentration is high enough, the iron may precipitate upon oxidation and hydrolysis. Drainage from coal piles may contain inaddition to the aforementioned constituents, high concentrations of dissolved solids and significant amounts of copper, zinc, and manganese. Other materials may also be present that are the result ofthe reaction of sulfuric acid with minerals and organic compounds present inthe coal. Raw Waste Load Coal Pile. Almost all ofthe plants that were visited 

### -- allowed coal piledrainage to drain to either the surface water, storm sewers, 

### or nearby land. An exception was plant No. 9163, which stored all of itscoal under roof, thus eliminating any drainage problems.DRAFT General chemical characteristics ofcoal piledrainage were discussed under the previous heading. Reference 

### 16 lists ranges for some of the elements present incoal piledrainage, which are shown below: El ement Concentration Range, mg/l Copper Iron Zinc Floor 

### -- and Yard Drains. Drainage from floor and yard drains inmost cases can be assumed to be a negligiblewaste source. Many plants exercise meticulous care,to prevent oil leaks and spills from reaching floor drains by using drip pans and oil absorbing materials. Some plants particularly those in, open areas or indry regions, have no need foryard drains and have no drains installed. Reference 16 listcharacteristics ofwastes fromyard and floor drains, which are summarized below: Parameter BOD TSS pH Surfactants Chromium Lead Phosphorous Oil and Grease Concentration Range (mg/l) 

### 2-4 0-5 Low-Neutral Present 0-20 Present 0-10 Present Wastewater Treatment None of the plants that were visited used any type of coal piledrainage treatment system. One plant No. 7116 discharged floor drainage (along with other wastes) to 

### a settling tank before discharge to a POTW. Other plants discharged floor and yard drainage without treatment either directly to surfacewater or to a POTW. EffluentWaste Loads Informationwas not available on treated wastewater before discharge to the POTW.DRAFT AIR POLLUTION CONTROL EQUIPMENT Liquidwaste disposal problems associatedwith air pollution control equipment are mainly limited tosystems for the control of S02. - Control systems for

## SO2can be further divided into "throwaway" and "recovery" processes. Throwaway processes produce a sludge or cake that must be disposed of. Recovery processes produce either elemental sulfur, sulfuric acid, or gypsum, which are marketable and have no disposal problems. The following discussion will be limited toa throwaway process. The greatest number ofexisting flue gas desulfurization systems (including recovery and throwaway) use tail-end scrubbing with lime and/or limestone. Those scrubbing systems, installed after the boiler, remove particulates as we11 as sulfur dioxide by reacting the flue gas with slurries of lime or limestone forming calcium sulfates and sulfites. The calcium sulfate/sulfite sludge isusually piped to large settling ponds. 

### A small number ofexisting throwaway systems are ofthe double-alkali type. Inthese systems, sodium or ammonium sulfates and sulfites are used as a scrubbing solution. After contacting the flue gas, the scrubbing solution isreactedwith limestone or lime toprecipitate calcium sulfi teand sulfate and regenerate the solution for recirculation tothe scrubber. Scrubber wastes consist ofa dry filtercake. Figure V-17 shows a flow diagram for an air pollution control scrubbing system. Water 

# 'e

None ofthe twenty-two plants visited inthe study used water tocontrol SOX emissions. This can be accounted for by the fact that the majority of the plants burned low sulfur (1 percent) coal or oil thereby eliminating the need for air pollution control devices.

Raw Waste Load None ofthe utilitiesvisited had flue gas desulfurization equipment. Since thewastes from these systems are mostly inthe form ofsludges, which are disposed ofon land, no problems with waste discharges to POTW's are anticipated.

### DRAFT

STACK CASES



### I I I I I I I I STEAMTO TURBINES 4 

### I STACK CASESI ).---- I I I 

# + I



# . I BOILER I I I I FLUEGASES 

### l-----J

INLET SCRUBIER Lmuou

OVtHFLOW CLARIFIER THICKENFH

WATER MAKEUP OVERFLOkV SETILIN(;

IJNl>tItFLOW



### FIGURE 

### V-17. Flow Diagram For Air Pollution Control Scrubbing System (Ref. 

### 14)DRAFT

Wastewater Treatment None ofthe plants discharged SO& removal wastewaters to the POTW. EffluentWaste Load Information was not available on treated wastewater before discharge tothe POTW. MISCELLANEOUS WASTE STREAMS Sanitary Wastes. Sanitary wastes from steam-electric plants are similar tomunicipal domestic wastes with the absence of laundry or kitchenwastes. The volume ofwaste flow is dependent upon the number of employees. Plant Laboratory Wastes. Many steam-electric plants have laboratories for the chemical analysis ofvarious process streams within the plant. Depending on the analyses performed, thewaste from this source will contain a large variety ofchemicals, albeit insmall amounts. Intake Screen Backwash. Power plants thatwithdraw cooling water from a natural body, such as a lake or river, use traveling screens toprevent debris from entering the intake system. Occasionally the debris from these screens is collected, and the screens are washed with hoses. Supplementing Cooling Water Systems. These cooling systems are generally maintained for such uses as bearing and gland cooling for pumps and fans. The systems may be oncethrough or recirculating. Chemicals are not used inoncethrough systems, except for occasional shock chlorination. Recirculatingsystems use water ofhigh purity, supplemented by pretreatedmakeup water. Chromates, borates, and nitrates are used inrecirculating systems to prevent scale formation. ConstructionActivity. The construction of buildings and equipment adjacent to power plants can cause the presence ofadditional amounts of suspended solids and turbidity inthe storm-water runoff due tothe erosion of soil disturbed by the construction activity.

### DRAFT


### Water 

### - Use Housekeeping. Housekeeping water usage, which includes floor washing and sanitarywater (bathrooms, sinks, etc.), amounts to less than one percent of the total. Only two plants of the twenty-two in

### the study had any substantial floorwash water usage these being plant No. 6421 with 

### 13.08 liters per MWH 

### and plant No. 6294 with 1.71 liters per MWH. 

### The following table liststhe water for sanitary purposes. Plant No.

Miscellaneous Cooling. Miscellaneous cooling needs include bearing cooling water, cooling of compressors, and other extraneous equipment cooling needs. Water usage varied 

### for six plants from a low of 1.59 liters per MWH 

### for plant No. 9396 to a high of 1.45~104 forplant No. 8356. Using the least squares analysis meThod for the normalized data, a coefficient of determination of 0.945 was calculated indicating that approximately 94 percent of the data variance could be accounted for by 

### the least squares straight line.DRAFT Raw Waste Load Sanitary Wastes. Reference 14 states that the per capita sanitary waste load isgenerally 25-35 gal/day (94.5-132 liters/day) from steam-electric power plant. The reference also lists the number ofemployees per MW that may be expected to be found attypical power plants: operational personnel: 1 per 20-40 MW maintenance personnel: 1 per 10-15 MW administrative personnel: 1 per 15-25 MW The flow, BOD?, and suspended solids per capita load can be estimated by the following (14): Fl ow BOD5 TSS Office-Administrative 0.95 cu (per capita) m/day 309 (0.071b) 709 (0.15 lb) (25 gpd) Plant (per capita) 0.133 cu m/day 409 (0.09 1b) 859 (0.19 Ib) (35 gpd) Plant Laboratory Wastes. The volume of wastes from in-plant laboratory can be assumed to be negligible. Reference 14 suggests that 

### ifa toxic materials problem isfound to originate from a laboratory drain, itmay be appropriate to either: (1) change the test procedure, (2) contain the waste for separate treatment, or (3) remove the waste from the site. Supplementary CoolingWater Systems. Wastes are discharged from recirculating cooling systems during blowdown, which may typically be twenty liters per day with a settleable solids content of 1-2 ppm (14). Additional wastes are discharged during drainage and cleaning operations, which are infrequent. Plants which use once-through systems may discharge the effluent from the entire system toa POTW. This waste streamwill probably contain chlorine, and the stream is usually ofsignificant volume. Construction Activity and Intake Screen Backwash. The nature and duration of these wastes do not contribute significantly tothe total waste load.

### DRAFT



### Wastewater Treatment Sanitary Wastes. Sanitary wastes are generally discharged directly to POTW's or septic tanks without treatment. 

### An exception is plant 7116, which pretreats sanitarywastes (along with other wastes) in a settling tank before discharge to a POTW. 

### Plant Laboratory Wastes. Most plants combine laboratory drains with other sanitary plant plumbing, and discharge the waste without pretreatment. Supplementary Cooling Water Systems. Supplementary cooling system wastes are usually discharged directly, although one plant 7116, discharged the waste to a settling tank before discharge to a POTW. 

### Construction Activity

# and Intake Screen Backwash. Most plants do not treat thesewastewaters. Intake screens are generally backwashed into the water source. Effluent Waste Loads. Information is not available on treated effluent from miscellaneous waste streams. THE 

### POTW 

### PROCESS -- 

### Preliminary Physical Treatment Most POTW's employ initial physical treatment of wastewater for the removal of course materials, settleable solids, grease, and floatingmaterial. Bar Racks and 

### Comminutors. These devices are used as 

### the first step in wastewater treatment to remove large solid materials. Bar racks consist of large, parallel steel bars placed perpendicular to the flow of wastewater. The bars trap and retain large solids, which are removed mechanically by a series of vertically-moving rakes connected to a motor-driven, endless chain belt. The solids are scraped off the racks with largemechanical arms, and may then either be collected for land disposal or ground in disintegrators and returned to the flow. Smaller POTW's may use comminutors, which are motor-driven cutting devices partially submerged in a narrow channel, to grind up 

### large materials as they pass through.DRAFT

GritChambers. Gritchambers are usually found inlarger POTW'S. They are generally located after bar racks, and are designed to remove sand, cinders, or other heavy particles that have high settling velocities. Gritchambers may be oftwo types: horizontal-flow, and aerated. Horizontal-flow grit chambers consist simply of a channel designed to maintain a constant flow velocity regardless ofthe volume ofwater passing through the channel. The flow velocity is lowered sufficiently over that ofthe influentwastewater to allow grittosettle tothe bottom. Removal ofthe grit may be done either mechanically or by hand. Aerated gritchambers consist of a spiral-flow aeration tank. The velocity offlow inaerated chambers isdetermined by the volume of the tank and the quantity ofairthat is supplied. Aerated grit chambers are always cleaned mechanically. Primary Sedimentation. Primary sedimentation isused after preliminary removal ofsolids inracks and grit chambers and priortobiological treatment. The purpose of primary sedimentation, when used prior to biological treatment, is to reduce the suspended solids and BOD load on the biological treatment units. This isaccomplished inlarge, rectangular (or circular) sedimentation tanks that provide a sufficient detention time for the removal of settleable solids and floating material. Grease and other floating materials are skimmed offfrom the surface with large rotatingarms. Solids that settle tothe bottom ofthe tank (known as primary sludge) are mechanically pushed into a hopper, where they are collected for further treatment. Primary sedimentation tanks, ifdesigned properly and operated correctly, will remove 50 to65 percent ofthe suspended solids inthe influentwastewater and from 25 to

### 40 percent ofthe BOD. 

### Ifprimary sedimentation isused as the only means oftreatment, the effluent isusually chlorinated to remove pathogens. Secondary Biological Treatment Secondary biological treatment isused to convert soluble and colloidal organic material into settleable flocculant material that can be removed insedimentation tanks. Two types of biological treatment processes are most often employed: (1) the activated-sludge process, and (2) trickling filters.DRAFT
Activated-Sludge Process. The activated-sludge process consists ofan aerated basin containing a large mass of microorganisms and flocculated solids, known as the mixed liquor, followed by a sedimentation tank inwhich the solids are removed. The sedimentation tank may either be part ofthe same structure as the aeration basin, or itmay be completely separate. Part of the solids that settle inthe sedimentation tank (the secondary sludge) is removed for further treatment, and part isrecycled tothe aeration basin. The effluent from the sedimentation tanks isusually chlorinated. Bacteria make up the largest portion of the microorganisms present inthe activated sludge, and are responsible for the majority of the waste stabilization that occurs. The mechanisms by which bacteria stabilize a waste istwofold, consisting of: (1) consumption oforganic matter, which is partiallyoxidized to lower energy compounds and partially converted to new cellular material, and 

### (2) the production of polymers and slime that bind bacterial cells and other suspended material intoflocculant particles that can be removed by sedimentation. Other microorganisms may also be present, such as protoza, which consume bacteria that have not flocculated, and rotifers, which consume small floc particles that have not settled. Activated sludge systems are usually from 

### 55~95 percent efficient inremoving BOD, and from 55-95 percent efficient inremoving suspended solids (Figure V-18). Trickling Filters. Trickling filters consist of a bed of rocks or plastic material that support a growth ofmicrobial material (slime layer). wastewater issprayed over the top of the bed, which iscircular, with a rotating distributor. As the waste percolates through the bed, organic material isadsorbed onto the slime layer. At periodic intervals, partly because ofthe increase in thickness ofthe slime layer, the microorganisms inthe layer lose their a b i l i t y t o cling tothe surface of the filtermedia and the slime layer iswashed off by the wastewater (a process called "sloughing"). (Figure V-18).

### DRAFT

Influen Was e 

### Sludge 

# i

Activated Sludge Process 

# t Effluent



## ~i udge

Infl uen Sludge ReturnLine We11 Trickling Filter Process nal dimentation

FIGURE 

### V-18. Flow Diagram ofSecondary Treatment Methods

V-63

### DRAFT 

### Trick1ing filters are divided into two categories: low-rate and high-rate, based on organic loading rates. Both types of filters achieve equivalent BOD 

### removal efficiencies, but 

### high-rate filters are advantageous since they have a higher rate of BOD 

### removal (and thus can accept higher influent flow rates) than low-rate filters. This is achieved by recycling a portion of the influent to return viable organisms back to the filters. Low-rate filters have no recycle. Both types of filters are followed by a settling tank (clarifier)to remove suspended solids produced during sloughing. The effluent from the settling tank is generally chlorinated. Trickling filters are from 50-95 percent efficient in the removal of BOD, 

### and 30-92 percent efficient in the removal of suspended solids. Figure V-19 shows awastewater treatment process diagram utilizing activated sludge or trickling filters. T-reatment and Disposal of Sludge. The problem of disposing of sludges produced during primary and secondary treatment is one of the most complex tasks faced by the engineer. Techniques for dealing with sludges are varied, but most involve: (1)digestion, followed by (2) 

### conditioning, and (3)

### dewatering and drying (FigureV-20). Digestion isa biological process for reducing the volume of sludge. Two types of digesters are in use: anaerobic, and aerobic. Anaerobic digesters are closed, heated tanks in which various microorganisms decompose organic and/or inorganic matter without the presence of oxygen, forming methane, carbon dioxide, and sludge solids. The methane that is involved during the process can be used as a fuel, and its rate of production is one of the best measures of the satisfactory operation of the digester. Chemical conditioning, followed by centrifugation or vacuum filtration, isusually used to treat sludge solids during anaerobic digestion. Chemical conditioning involves the use of ferric chloride, lime, alum, or organic polymers to coagulate the solids and release absorbed water. Centrifugation and vacuum filtration are physical operations that are used to remove water from the sludge solids prior to final disposal. Aerobic digestion ismuch like the activated sludge process, involving consumption of organic compounds in

### sewage by an aerated mass of microorganisms. As the supply of organic material 

### run out, the microorganisms begin to consume their own protoplasm. Sludge solids from aerobic digesters are stable and are more easily dewatered by vacuum filtration or drying on sand beds.

### Acitvated Sludge Treatment Scheme Screenings Grit Sludge Waste sludge Return sludge C'2 

# f

L



### Primary Trickling Chlorine 

### Bar racks Grit chambers 

### sedimentation filters Settljng 

### tank 

### contact chamber t



### Screenfngs Grit ~l 

### udge Waste sludge

Trickling Filter Treatment 

### Scheme b r 

## Y,

I



### FIGURE V-19. 

### Wastewater Treatment 

### Flow Diagram 

### Influent

# -

r 

### Return effluent L 

### - t. r 

# -

P Primary Aeration tank settlingtank 

### Chlorine Bar racks Grit chambers sedimentation 

### contact chamber

* r 

### P 3- + F 

### Effluen I



### Influent

# 1 1 

### Effluent 

# - 

# - 3

### Ana,erobic sludge digestion Chemical conditioning centrifuge

FIGURE V-20. 

### Flow Diagram forSludge Treatment 

# * Sludge from sedimen- ati ion 

### tanks sludge 

# f Supernatant Sludge Disposal Scheme Dewatered sludge to ultimate disposal o ;O 

### > -r1 -4 

### r

Digested Centrat

## I 

# -

c 

# - r rDRAFT

Tertiary Treatment Many chemical constituents present inwastewater, especially nitrogen and phosphorus, are slightly affected by conventional primary and secondary treatment. Since these chemicals can have adverse effects on the receivingwater by promoting the growth of algae and other unwanted aquatic vegetation, their removal isdesirable insome cases. Although tertiary treatment processes are still uncommon, their use is receiving considerable attention. Two processes, nitrification for the removal of nitrogen, and precipitation for the removal of phosphorus, will be discussed. 

### Nitrification-Denitrification. This process appears to be the most promising for the removal of nitrogen. The technique involves aerobic conversion of ammonia to the nitrate form (nitrification), followed by anaerobic conversion of the nitrates to nitrogen gas (denitrification). Both steps involve the production of specialized groups of bacteria, and require detailed attention tooperating and environmental conditions. Denitrification requires the addition ofa supplemental carbon source for successful operation. Methanol isusually used. 

### Nitrification-denitrification isfrom 60-65 percent efficient inremoving nitrates. Figure 

### V-21 shows a flow diagram of the 

### nitrification-denitrification process. Chemical Precipitation. Precipitation of phosphorus can be achieved by the addition of chemicals such as lime, alum, and ferric-chloride, or sulfate. These chemicals are usually added tothe raw wastewater and the phosphorus is precipitatedduring primary sedimentation, however, these chemicals can also be added inthe activated-sludge aeration tank or tothe secondary clarifier. Removal of phosphates by precipitation inprimary sedimentation tanks is from 90- 95 percent efficient. EFFECTS 

### - OF STEAM-ELECTRIC WASTEWATERS - ON POTW'S The wastewaters discharged by steam-electric plants vary greatly inflow and waste loadings. For the twenty-two plants visited during this study, the steam-electric wastewaters represented less than five percent of the total POTW influent. Table V-13 lists the combined discharge rate for each steam-electric plant along with the associated POTW influent flow and treatment scheme.

### Nitrification Nitrogen Removal Scheme Waste sludge ~aste sludge pH 

### adjustment pH 

### adjustment 

# A Chemical addition

Denitrification Secondary t 

### effluent



# . r

I



### FIGURE V-21. Flow Diagram of Ni

### tr-ification

# - Denitrification Process 

# r Final effluent

Plug flow reactor plug flow reactor Sludge return Sludge return Settling tank Settling tankTable V-13. POWER PLANT AND POTW FLOWS

15,000 

# I 10.0 x lo6 

# I 0.15 

# I Activated sludge, (56,700) (22.7 x 106) aerobic digestion 

# I --- Plant

No 9600

9650

9369 Combined Flow to POTW, gpd (]/dl No data (plant has been usin POTW for only one year! 100.00 (378,000)

2.350 (8.880)

1.580 (5,970) 2.000

9585 POTW Average Flow, gpd (l/d)

97.5 xlo6 (369 x lo6) 2.4 xlo6 (9.1 x 106)

300,000 (1.1 x 106) 3-50 x 1o6

7116

8696

8135

91 63

6387

8392

1.4 x 10 

# 1 1.9 

# 1 Activated sludge 

# 1 (1.3 x 106) 

# I (7,560)

600 (2,270)

16214 

# 1 No data

### - operates only 1.4 x lo6 

# 1 (5.3 x lo6) 

# 1 -- 

# I Activated sludge 50 hourslyr 

# I % of POTW Flow

0.10

0.098

0.50

0.01

Data incomplete

173.000 (654,000)

150,400

46.900 (177.000)

9,500 (35,900)

126,000 (476,000) 6293

7308

8875

7968 POTW Treatment Scheme



# - Actfvated sludge, anaerobic digestion Rotatingbiological surfaces; anaerobic dioestion

Activated sludge. aerobic digestion Activated sludse. (1,320 x lo6)

4.5 xlo6 (17.0 x lo6)

2 xlo6 (7.6 x 106)

315 x lo6 (1.190 x 106)

31.1 xlo6 (120 x 106)

--- ------ - -- 9,100 (34,400)
902,000 (3.41 x lo6)
423,000 (1.60 x lo6)

Data fncomplete 3.5 xlo6 (13.2 x lo6)

350 xlo6 (1,320 x lo6)

6294 0.01

0.46

0.29

1.4



# --- anaerobic digeition Oxidation pond



## ---

0.049

Activated sludge trick1ing filters anaerobic digesters Primary treatment only secondary treatment facilities being built Activated sludge, trick1ingfilters, anaerobic digestion

--- 

# I 35.000 (132,000) Activated sludge

Activated sludge. anaerobic digestion No POTW at present

### - to be hooked up toWest Palm Beach POTW in1978

### - Sewers presently run to ocean

1.4 x 10 6 (5.3 x 106) Trickling filters; anaerobic disrstion Trickling filters; no digestion Activated sludge, aerobic diqestion 10xlo6 (38 x lo6)

220.000 (832,000) 1.5 x lo6 (5.7 x 106) 0.47

4.3

8.4

2.5 Activated sludgeDRAFT

Raw Waste Load 

### - Waste loads inthe combined discharge are affected by any occurrence inthe steam-electric which use and discharge water. The waterborne waste loads inthe combined discharge for six 

### (6) plants are shown inTable V-14 The major pollutants are chemical oxygen demand and dissolved and total solids, with lesser values of iron, nickel, phosphates and total and hexavalent chromium.Table 

### V-14. 

### RAWWASTE F L O W S A N DLOADINGS

# - COMBINED DISCHARGE

### TO 

### POTW

- LlDay LIMWH LIDay LIWH LIDay LIWWH L/l)ay L/MWH L!Day L/W&H L/@~Y LIWWH 518.090 1870 238.OOO 755 0 779 ,272.0OlO '19.9 35.500 150 254,000 593 mq/l Q/NWH m~/l a/;,lWH mqll q/MWY mq/l g vg/l g1FiWH mgll g/WH



### 1Chromium 

### 1<O.C2 Uncertain 

### 1 8.1 6.1 

### 1 1.76 0.403

### 1<0.02 (0.02 

### 1 0.033 0.005 

### 1 9.7 5.7 

### 1 t * 8135 Combinad Dischaw 6293 7308 8392 - 

# - .-

--- Chrowium+6 Copver Cy~nide (Total)

I w --.1 8696 PLANT NO

0.66 0.15 0.45 0.10

- (0.0005 (3.005

Oil and Grease Phosphate (Total) Total Dissolved Solids Total Suspended Solids Total Sollds Surfactants Zinc 

# - Combined Discharge Combined Discharge 6387

I,l?T r,,,, E'rlATER SOURCE

0.006 0.01 0.02 0.04 0.036 0.01 Iron Nickel Combined Discharge 

### ( Combined Discharge Combined Oisc9arge

0.01 0.0004 0.46 0.013 <0.005 C0.005 - 8.0 6.0 0.04 0.03 <O .005 (0.005

Quantitiesof parameters incombined discharge calculated by fractional additionofparameters inseperate contributing streams (1 .O Uncertain



### ----- 

### ----- 1454 2719

241 451 1695 3170 0.64 1.2 (0.03 Uncertain 0.02C 0.003 0.5 0.008 (0.005 <0.005 - 7.19 4.26 0.03 0.02 0.12 0.71 0.71 0.54 (0.03 (0.03

1.2 0.91 

### 1 5.8 1.3 2.3 0.092 0.05 0.002 2479 98.9

70.2 2.8 

### ---- 

### ----- 16 12

<1.O (1 .O 14.7 3.37 12 2.7

(0.011 (0.011 0.045 O.OC68 

### ----- ------ 208C 476

226 51.7

0.024 0.04 0.07 0.1 0.059 0.035 0.56 0.33 (1.O <1.0 4.4 0.66 580 87

159 28.3 16 12



### ----- ----- 1.47 0.337 

## ----- ------ 2.6 2.0 0.88 0.035 (0.03 (0.03 <l.o (1.0

. 5.8 6.4 1298 763

5.6 3.3 770 115



### ----- ------ 0.11 0.0044 1304 773

# - 2306 520 5.79 0.868 f0.03 ~0.03

2549 102 0.12 0.71 (0.03 (3.03DRAFT
WASTE COMPARISON Effluentdata gathered from the eight 

### (8) plants sampled during this study were compared with similar data gathered insupport of the "Development Document for Effluent Limitations Guidelines and Standards of Performance for the Steam Electric Power Generating Point Source Category" (14). Comparison was made to identify similarities and differences inthe quality and quantity of aqueous plant effluents. Waste streams for which data was available for comparison include:



### a Recirculating Condenser Cooling Water

0 Later Treatment Wastes



### m Boi

### 1er Bl owdown



### a Ash Handling Wastes These data may be found inTable V-15. Recirculating Condenser Cooling Water Flow data inthis study tended to coincide with lower flows reported inthe development document (14) and were similar. Concentrations of BOD, phosphate, dissolved solids, suspended solids, total solids, and zinc observed inthis study were within the range of those reported inthe Development Document. Concentrations of chromium, copper, ironand nickel observed inthis study tended to be lower than those reported inthe development document. This difference isprobably due to lower influent loadings of these heavy metal components. Metals such as iron, and copper tend to be removed during municipal water treatment. Most of the plants contacted inthis study used municipal water as raw feed water for all purposes. Water Treatment Wastes Flows and parameter concentrations ofwastes observed inthis study were within the range of those reported in the development document.DRAFT

Boi1 er Bl owdown Flow data for boiler blowdown observed inthis study was within the range ofthose reported inthe development document. Concentrations of all parameters observed inthis study were similar to those reported inthe development document with the exception of BOD, and zinc. BOD values observed inthis study tended to be higher than those reported inthe development document. Observed zinc values tended to be lower. BOD difference inthis low range are not significant as the test method isnot precise inthis range. Zinc concentrations are understandably lower for all discharges observed inthis study due to use of municipal water as influentwater. Ash Handling Wastes Wastewater flows of ash handling wastes observed inthis study were within the range of those reported inthe development document (14). Concentrations of parameters observed inthis study were within the range of those reported inthe development document, with the exception of phosphate. Phosphate concentrations observed inthis study were higher than those reported inthe development document. Higher maximum phosphate concentrations are probably due to the variable nature of coal impurities. Summary Overall, values, of effluent flows and parameter concentrations observed inthis study were similar tothose reported in data referenced inthe development document (14). The few parameters inthis study that lay outside the range of development document data tended to be lower, reflecting the higher quality of the municipal water used as influent water for the stations contacted inthis study. Therefore, itmay be concluded that the stations affected by the results of this study are not different from those (direct dischargers) affected by the development document (14).DRAFT SECTION VI SELECTION OF POLLUTANT PARAMETERS

INTRODUCTION Aqueous pollutants originating from steam electric power generating facilities which are of potential harm to either publicly-owned treatment works (POTW) or to receiving waters atthe point of discharge ofthe POTW are identified inthis section. RATIONALE 

### -- FOR THE SELECTION

# OF POLLUTANT PARAMETERS Pollutants were selected based on their harmful effects on treatment works. Ifthe pollutant passes through typical treatment works, itwas selected on the basis of its potential for harm to receivingwaters. The following factors were considered inthis selection:



### m Potential harm to POTW. The pollutant may impair thexiat- biological treatment systems by either: (1) causing the death of some or all ofthe microorganisms that are essential to the operation of the POTW, or 

### (2) impairing the activity of these microorganisms so that theirwaste-consuming efficiency is lowered. Examples of treatment units that may be adversely affected by pollutants are: trickling filters, activated sludge units, anaerobic digesters, and nitrification units. Potential 

### --- harm tothe receiving water. 

### If the ~ollutant is not removed or is removed inadequately by the POTW, itmay be of significant harm to the receiving water. In this respect, the pollutantmay cause damage to the fish and plant life of the water, or itmay render the water unsuitable for use for domestic, industrial, or recreational purposes.DRAFT Presence orabsence inplant effluents Parameters such as total suspended solids (TSS), biochemical oxygen demand (BOD), and chemical oxygen demand (COD) that are normally removed (to a given extent) by treatment plants are also discussed. This discussion does not necessarily indicatethat these parameters are of harm to a POTW, but only that they were part of routine analysis ofeffluent samples. 

### A discussion of the effects of selected pollutants on treatment plants is included inAppendix C. The following discussion is primarily relatedto the effects of the pollutants on receiving waters. Properties

# of Selected Pollutant Parameters Acidity and Alkalinity

# - pH. Although not a specific pollutant, pH isrelatedtothe acidity or alkalinity of a wastewater stream. It isnot a linear or direct measure of either, however, itmay be properly used 

### as a surrogate tocontrol both excess acidity and excess alkalinity in water. The term pH isused to describe the hydrogen ion

# - hydroxyl ion balance inwater. Technically, pH isrelated to the hydrogen ion concentration or activity present ina given solution. pH numbers are the negative logarithm of the hydrogen ion concentration. A pH of 

### 7 indicates neutrality or a balance between free hydrogen and free hydroxyl ions. Solutions with a pH above 

### 7 indicate that the solution 

### isalkaline, while a pH below 

### 7 indicates that the solution isacidic. Knowledge ofthe pH ofwater orwastewater isuseful in determining necessary measures for corrosion control, pollution control, and disinfection. Waters with a pH below 

### 6.0 are corrosive towater works structures, distribution lines, and household plumbing fixtures such as iron, copper, zinc, cadmium, and lead. Low pH waters not only tend to dissolve metals from structures and fixtures but also tend to redissolve or leach metals from sludges and bottom sediments. The hydrogen ion concentration can affect the "taste" ofthe water and at a low pH, water tastes "sour."DRAFT

Extremes of pH or rapid pH changes can exert stress conditions or killaquatic lifeoutright. Even moderate changes from "acceptable" criteria limits of pH are deleterious to some species. The relativetoxicity to aquatic lifeof many materials is increased by changes in thewater pH. For example, metalocyanide complexes can increase a thousand-fold intoxicitywith a drop of 1.5 pH units. Similarly, the toxicity of ammonia isa function of pH. The bactericidal effect ofchlorine inmost cases is less as the pH increases, and itiseconomically advantageous to keep the pH close to

### 7. Acidity. Acidity isdefined as the quantitative ability of awater to neutralize hydroxyl ions. It isusually expressed as the calcium carbonate equivalent of the hydroxyl ions neutralized. Acidity should not be confused with pH value. Acidity isthe quantity of hydrogen ions which may be released to react with or neutralize hydroxyl ions while pH isa measure ofthe free hydrogen ions ina solution atthe instant the pH measurement ismade. 

### A property ofmany chemicals, called buffering, may hold hydrogen ions in solution from being inthe free state and being measured as pH. The bond of most buffers isratherweak and hydrogen ions tend to be released from the buffer as needed to maintain a fixed pH value. Highly acidwaters are corrosive to metals, concrete, and livingorganisms, exhibiting the pollutional characteristics outlined above for low 

### pH waters. Depending on buffering capacity, water may have a higher total acidity at pH values of 

### 6.0 than otherwaters with a pH value of

### 4.0. Alkalinity. Alkalinity isdefined as the ability ofa water toneutralize hydrogen ions. It isusually expressed as the calcium carbonate equivalent ofthe hydrogen ions neutralized.

### DRAFT 

### Alkalinity is commonly caused by the presence of carbonates, bicarbonates, hydroxides, and to a lesser extent by borates, silicates, phophates, and organic substances. Because of the nature of the chemicals causing alkalinity, and the buffering capacity of carbon dioxide in water, very high pH 

### values are seldom found in natural waters. Excess alkalinity, as exhibited in a high pH 

### value, may make water corrosive to certain metals, detrimental tomost natural organic materials, and toxic to living organisms. Ammonia ismore irritating athigher pH. 

### The lacrimal fluid of the human eye has a pH 

### of approximately 7.0 and a deviation of 0.1 pH 

### unit from the norm may result in eye irritation for the swimmer. Appreciable irritationwill cause severe pain. Oil and Grease -- 

### Because of widespread use, oil and grease occur often in wastewater streams. These oilywastes may be classified as follows:

e 

### Light Hydrocarbons. These include light fuels such as gasoline, kerosene, and jet fuel, and miscellaneous solvents used for industrial processing, degreasing, or cleaning purposes. The presence of these hydrocarbons may make the removal of other heavier oily wastes more difficult. Heavy Hydrocarbons, Fuels, and Tars. These include -- the crude oils, diesel oils, #6 

### fuel oil, residual oils, slop oils, and in some cases, asphalt and road tar.

a 

### Lubricants

# and Cutting Fluids. These generally fall into two classes: non-emulsifiable oils such as lubricating oils and greases, and emulsifiable oils such as water soluble oils, rolling oils, cutting oils, and drawing compounds. Emulsifiable oils may contain fat soap or various other additives.

0 

### Vegetable and Animal 

### --- Fats and Oils. These originate primarily from processing of foods and natural products. - -

### DRAFT 

### These compounds can settleor float and may exist as solids or liquids depending upon factors such as method of use, production process, and temperature of wastewater. Oil and grease even in small quantities cause troublesome taste and odor problems. Scum lines from these agents are formed on water treatment basin walls and other containers. Fish and water fowl are adversely affected by oils in their habitat. Oil emulsions may adhere to the gills of fish causing suffocation, and the flesh of fish is tainted when microorganisms that were exposed towaste oil are eaten. Deposition of oil in the bottom sediments of water can serve to inhibit normal benthic growth. Oil and grease exhibit an oxygen demand. Levels of oil and grease which are toxic to aquatic organisms vary greatly, depending on the type and the species susceptibility. However, ithas been reported that crude oil in concentrations as low as 0.3 mg/l is extremely toxic to fresh-water fish. It

### has been recommended that public water supply sources be essentially free from oil and grease. Oil and grease in quantities of 100 l/sq km 

### (10 gallons/sq mile) show up 

### as a sheen on the surface of a body of water. The presence of oil slicks prevent the full aesthetic enjoyment of water. The presence of oil in water can also increase the toxicity of other substances being discharged into the receiving bodies of water. Municipalities frequently limit the quantity of oil and grease that can be discharged to their wastewater treatment systems by industry. Chemical Oxygen Demand (COD) 

### and Biochemical Oxygen Demand (BOD) 

### The Chemical Oxygen Demand (COD) 

### is a purely chemical oxidation test devised as an alternate method of estimating the total oxygen demand of

### a wastewater. Since the method relies on the oxidation-reduction system of chemical analyses rather than on biological factors, itismore precise, accurate, and rapid than the Biochemical Oxygen Demand (BOD) 

### test. The COD 

### test iswidely used 

### toestimate the total oxygen demand (ultimate rather than 5-day BOD) 

### to oxidize the compounds in a wastewater. Itis based on the fact that organic compounds, with a few exceptions, can be oxidized by strong chemical oxidizing agents under acid conditions with the assistance of certain inorganic catalysts.DRAFT The COD test measures the oxygen demand ofcompounds that are biologically degradable and ofmany that are not. Pollutantswhich are measured by the BOD5 test will be measured by the COD test. Inaddition, pollutantswhich are more resistanttobiological oxidationwill also be measured as COD. COD isa more inclusive measure ofoxygen demand than isBOD5 and 

### will result inhigher oxygen demand values than will the BOD5 test. The compounds which are more resistant tobiological oxidation are becoming ofgreater and greater concern not only because oftheir slow but continuing oxygen demand on the resources of the receivingwater, but also because oftheir potential health effects on aquatic lifeand humans. Many ofthese compounds result from industrial discharges and some have been found tohave carcinogenic, mutagenic, and similar adverse effects, either singly or incombination. Concern about these compounds has increased as a result of demonstrations that their long lifeinreceivingwatersthe result of a slow biochemical oxidation rate--allows them tocontaminate downstream water intakes. The commonly used systems ofwater purification are not effective in removing these types of materials and disinfection such as chlorination may convert them intoeven more hazardous materials. Thus the COD test measures organic matter which exerts an oxygen demand and which may affect the health ofthe people. It isa useful analytical tool for pollutioncontrol activities. It provides a more rapidmeasurement ofthe oxygen demand and an estimate oforganic compounds which are not measured inthe BOD5 test. 

## BOD. Biochemical oxygen demand (BOD) isthe quantity of oxygen required for the biological and chemical oxidation of waterborne substances under test conditions. Materialswhich may contribute tothe BOD include: carbonaceous organic materials usable as a food source by aerobic organisms; oxidizable nitrogen derived from nitrites, ammonia and organic nitrogen compounds which serve as food for specific bacteria; and certain chemically oxidizable materials such as ferrous iron, sulfides, sulfite, etc. which will react with dissolved oxygen or are metabolized by bacteria. In most industrial and municipal wastewaters, the BOD derives principallyfrom organic materials and from ammonia (which isitselfderived from animal or vegetable matter).DRAFT The BOD of a waste exerts an adverse effect upon the dissolved oxygen resources of a body ofwater by reducing the oxygen available tofish, plant life, and other aquatic species. Conditions can be reached where all of the dissolved oxygen inthe water isutilized resulting inanaerobic conditions and the production of undesirable gases such as hydrogen sulfide and methane. The reduction ofdissolved oxygen can be detrimental tofish populations, fish growth rate, and organisms used as fish food. 

### A total lack of oxygen due to the exertion of an excessive BOD can result inthe death of all aerobic aquatic inhabitants inthe affected area. Water with a high BOD indicates the presence of decomposing organic matter and associated increased bacterial concentrations that degrade itsquality and potential uses. 

### A by-product of high BOD concentrations can be increased algal concentrations and blooms which result from decomposition of the organic matter and which form the basis of algal populations. The BOD5 (5-day BOD) test is used widely to estimate the pollutional strength of domestic and industrial wastes in terms of the oxygen that they will require ifdischarged into receiving streams. The test isan important one in water pollution control activities. It is used for pollution control regulatory activities, to evaluate the design and efficiencies ofwastewater treatment works, and to indicate the state of purification or pollutionof receiving bodies ofwater. Complete biochemical oxidation of a given waste may require a period of incubation too long for practical analytical test purposes. For this reason, the five-day period has been accepted as standard, and the test results have been designated as BOD5. Specific chemical test methods are not readily available for measuring the quantity of many degradable substances and their reaction products. Reliance insuch cases is placed on the collective parameter, BOD5, which measures the weight of dissolved oxygen utilized by microoganisms as they oxidize or transform the gross mixture ofchemical compounds inthe wastewater. The compounds are related tothe period of incubation. The five-day BOD normally measures only 

### 60 to

### 80 percent of the carbonaceous biochemical oxygen demand of the sample, and for many purposes this isa reasonable parameter. Additionally, it can be used toestimate the gross quantity ofoxidizable organic matter.DRAFT

The BOD5 test isessentially a bioassay procedure which provides an estimate of the oxygen consumed by microorganisms utilizing the degradable matter present ina waste under conditions that are representative of those that are likely tooccur innature. Standard conditions of time, temperature, suggested microbial seed, and dilutionwater for the wastes have been defined and are incorporated inthe standard analytical procedure. Through the use ofthis procedure, the oxygen demand ofdiverse wastes can be compared and evaluated for pollutionpotential and tosome extent for treatability by biological treatment processes. Because the BOD test isa bioassay procedure, it is important that the environmental conditions of the test be suitable for the microorganisms to function inan uninhibitedmanner atall times. This means that toxic substances must be absent and that the necessary nutrients, such as nitrogen, phosphorous, and trace elements, must be present. Total Suspended Solids (TSS) Suspended solids include both organic and inorganic materials. The inorganic compounds include sand, silt, and clay. The organic fraction includes such materials as grease, oil, tar, and animal and vegetable waste products. These solids may settle out rapidly and bottom deposits are often a mixture of both organic and inorganic solids. Solids may be suspended inwater for a time, and then settle to the bed of the stream or lake. These solids discharged with man's wastes may be inert, slowly biodegradable materials, or rapidly decomposable substances. While insuspension, they increase the turbidity of the water, reduce light penetration and impair the photosynthetic activity of aquatic plants. Suspended solids inwater interferewith many industrial processes, cause foaming inboilers, and incrustations on equipment exposed to such water, especially as the temperature rises. They are undesirable inprocess water used inthe manufacture of steel, inthe textile industry, inlaundries, indyeing, and incooling systems.

### DRAFT Solids insuspension are aesthetically displeasingwhen they settletoform sludge deposits on the stream or lake bed. They are oftendamaging tothe l i f e i nwater. Solids, when transformed tosludge deposits, may do a variety of damaging things, including blanketingthe stream or 1 ake bed and thereby destroying the livingspaces for those benthic organisms thatwould otherwise occupy the habitat. When ofan organic nature, solids use a portion ofall of thedissolvedoxygen available inthe area. Organic materials also serve as a food source for sludgeworms and associated organisms. Disregardingany toxic effectattributable to substances leached out by water, suspended solids may kill fishand shellfish by causing abrasive injuries and by clogging the gillsand respiratory passages ofvarious aquatic fauna. Indirectly, suspended solids are inimical toaquatic life because they screen out light, and they promote and maintainthe development of noxious conditions through oxygen depletion. This results inthe killingoffishand fishfood organisms. Suspended solids also reduce the recreational value ofthe'water. Turbidity. Turbidity ofwater isrelated tothe amount of suspended and colloidal matter contained inthe water. It 

### affects the clearness and penetration of light. The degree ofturbidity isonly an expression ofone effectofsuspended solids upon the character ofthewater. Turbidity can reduce the effectiveness ofchlorination and can result in difficulties inmeeting BOD and suspended solids limitations. Turbidity isan indirectmeasure ofsuspended solids. Chromium (Cr) Chromium isan elemental metal usually found as a chromite (FeCr204). The metal isnormally processed by reducing the oxidewith aluminum. Chromium and itscompounds are used extensively throughout industry. It 

### isused to harden steel and as an ingredient inother useful alloys. Chromium isalso used inthe electroplating industryas an ornamental and corrosion resistant platingon steel and can be used inpigments and as a pickling acid (chromic acid). The two most prevalent chromium forms found inindustry wastewaters are hexavalent and trivalent chromium. Chromic acid used inindustry isa hexavalent chromium compound which ispartiallyreduced tot,he trivalent from during use. Chromium can exist as either trivalent or hexavalentDRAFT 

### compounds in raw waste streams. Hexavalent chromium treatment involves reduction to the trivalent form prior 

### to removal of chromium from the waste stream as a hydroxide precipitate. Chromium, in itsvarious valence states, is hazardous to man. Itcan produce lung tumors when inhaled and induces skin sensitizations. Large doses of chromates have corrosive effects on the intestinal tract and can cause inflammation of the kidneys. Levels of chromate ions that have no effect on man appear to be so low as to prohibit determination to date. The recommendation for public water supplies isthat such supplies contain no more than 0.05 mg/l total chromium. The toxicity of chromium salts to fish and other aquatic lifevaries widely with the species, temperature, pH, 

### valence of the chromium, and synergistic or antagonistic effects, especially that of hard water. Studies have shown that trivalent chromium ismore toxic to fish of some types than hexavalent chromium. Other studies have shown opposite effects. Fish food organisms and other lower forms of aquatic lifeare extremely sensitiveto chromium and it also inhibits the growth of algae. Therefore, both hexavalent and trivalent chromium must be considered harmful 

### toparticular fish or organisms.

Copper isan elemental metal that is sometimes found free in nature and is found in many minerals such as cuprite, malachite, azurite, chalcopyrite, and bornite. Copper is obtained from these ores by smelting, leaching, and electrolysis. Significant industrial uses are in the plating, electrical, plumbing, and heating equipment industries. Copper isalso commonly used with

### other minerals as an insecticide and fungicide. Traces of copper are found in all forms of plant and animal life, and itis an essential trace element for nutrition. Copper isnot considered to be a cumulative systemic poison for humans as itis readily excreted by the body, but 

### itcan cause symptoms of gastroenteritis, with nausea and intestinal irritations, atrelatively low dosages. The limiting factor in domestic water supplies istaste. Threshold concentrations for taste have been generally reported in the range of 1.0 to 2.0 mg/l of copper whileDRAFT concentrations of5 to7.5 mg/l have made water completely undrinkable. It has been recommended that the copper in public water supply sources not exceed 1 mg/l. Copper salts cause undesirable color reactions inthe food industry and cause pittingwhen deposited on some other metals such as aluminum and galvanized steel. The textile industry isaffected when copper salts are present in water used for processing of fabrics. Irrigationwaters containing more than minute quantities of copper can be detrimental tocertain crops. The toxicity of copper to aquatic organisms varies significantly, not only with the species, but also with the physical and chemical characteristics of the water, including temperature, hardness, turbidity, and carbon dioxide content. Inhard water, the toxicity of copper salts may 

### be reduced by the precipitation of copper carbonate or other insoluble compounds. The sulfates of copper and zinc, and of copper and cadmium are synergistic intheir toxic effect on fish. Copper concentrations less than 1 mg/l have been reported to be toxic, particularly insoftwater, tomany kinds of fish, crustaceans, molluscs, insects, phytoplankton, and zooplankton. Concentrations ofcopper, for example, are detrimental tosome oysters above 0.1 ppm. Oysters cultured insea water containing 0.13-0.5 ppm of copper deposit the metal intheir bodies and become unfit as a food substance. Cyanide (CN) Cyanide isa compound that iswidely used inindustry primarily as sodium cyanide (NaCN) or hydrocyanic acid (HCN). The major use of cyanides i s i nthe electroplating industrywhere cyanide baths are used to hold ions such as zinc and cadmium insolution. Cyanides invarious compounds are also used insteel plants, chemical plants, photographic processing, textile dying, and ore processing. Ofall the cyanides, hydrogen cyanide 

### (HCN) is probably 

### the most acutely lethal compound. HCN dissociates in water to hydrogen ions and cyanide ions ina pH dependent reaction. The cyanide ion isless acutely lethal than HCN. The relationship of pH to HCN shows that as the pH is lowered tobelow 

### 7 there is less than 1 percent of the cyanide molecules inthe form ofthe CN ion and the rest is presentDRAFT as HCN. When the pH is increased to

### 8, 9, and 10, the percentage of cyanide present as 

### CN ion is

### 6.7, 42, and 87 percent, respectively. The toxicity of cyanides isalso increased by increases intemperature. 

### A rise of 10°C produced a two- totwo-to threefold increase inthe rateof the lethal action of cyanide. Inthe body, the CN ion, except for a small portion exhaled, is rapidly changed into a relatively non-toxic complex (thiocyanate) inthe liverand eliminated inthe urine. There isno evidence that the CN ion isstored inthe body. The safe ingested limitof cyanide has been estimated at something less than 18 mg/day, part ofwhich comes from normal environment and industrial exposure. The average fatal dose of HCN by ingestion by man is50 to 60 mg. It has been recommended that a 

### limitof 0.,2 mg/l cyanide not be exceeded inpublic water supply sources. The harmful effects ofthe cyanides on aquatic lifeis affected by the pH, temperature, dissolved oxygen content, and the concentration of minerals inthe water. The biochemical degradation of cyanide isnot affected by temperature inthe range of 10°C to35OC while the toxicity of HCN is increased at higher temperatures. On lower forms of lifeand organisms, cyanide does not seem to be as toxic as it istoward fish. The organisms that digest BOD were found to be inhibited at 60 mg/l although the effect ismore one of delay inexertion of BOD than total reduction. Certain metals such as nickel may form complexes with cyanide to reduce lethality, especially at higher pH values. On the other hand, zinc and cadmium cyanide complexes may be exceedingly toxic. Iron (Fe) Iron isan abundant metal found inthe earth's crust. The most common ironore is hematite from which iron isobtained by reduction with carbon. Other forms of commercial ores are magnetite and taconite. Pure iron is not often found incommercial use, but it isusually alloyed with other metals and minerals, the most common being carbon.DRAFT Iron isthe basic element inthe production of steel and steel alloys. Iron with carbon is used for casting of major parts ofmachines and itcan be machined, cast, formed, and welded. Ferrous iron is used inpaints, while powdered iron can be sintered and used inpowder metallurgy. Iron compounds are also used to precipitate other metals and undesirable minerals from industrial wastewater streams. Iron ischemically reactive and corrodes rapidly inthe presence of moist airand atelevated temperatures. In water and inthe presence of oxygen, the resulting products of ironcorrosion may be pollutants inwater. Natural pollutionoccurs from the leaching of soluble iron salts from soil and rocks and is increased by industrial wastewater water from pickling baths and other solutions containing ironsalts. Corrosion products of iron inwater cause staining of porcelain fixtures, and ferric iron combines with tannin to produce a dark violet color. The presence of excessive iron inwater discourages cows from drinking and, thus reduces milk production. High concentrations of ferric and ferrous ions inwater killmost fish introduced to the solution within a few hours. The killingaction is attributed to coatings or iron hydroxide precipitates on the gills. Iron-oxidizing bacteria are dependent on iron in water for growth. These bacteria form slimes that can affect the aesthetic values of bodies ofwater and cause stoppage of flows inpipes. Iron isan essential nutrient and micronutrient for all forms of growth. Drinking water standards inthe U.S. have set a recommended limitof 0.3 mg/l of iron indomestic water supplies based not on physiological considerations, but rather on aesthetic and taste considerations. Nickel (Ni) Elemental nickel isseldom found innature inthe pure state. Nickel isobtained commercially from pentlendite and pyrrhotite. It isa relatively plentiful element and iswidely distributed throughout the earth's crust. It occurs in-marineorganisms and isfound inthe oceans. Depending on the dose, the organism involved, and the type of compound involved, nickel may be beneficial or toxic. Pure nickel isnot soluble inwater but many of itssalts are very soluble.DRAFT The toxicityofnickel to man is believed to be very low and systematic poisoning of human beings by nickel or nickel salts isalmost unknown. Nickel salts have caused the inhibitionofthe biochemical oxidation of sewage. They also caused a 50 percent reduction inthe oxygen utilization from synthetic sewage inconcentrations of 3.6 to

### 27 mg/l ofvarious nickel salts. Nickel isextremely toxic tocitrus plants. It isfound in many soils inCalifornia, generally ininsoluble form, but excessive acidification ofsuch soil may render it soluble, causing severe injurytoor the death of plants. Many experiments with plants insolution cultures have shown that nickel at0.5 to 1.0 mg/l isinhibitory togrowth. Nickel salts can killfish atvery low concentrations. However, ithas been found to be less toxic to some fish than copper, zinc, and iron. Data for the fathead minnow show death occurring inthe range of 5 to43 mg/l, depending on the alkalinity ofthe water. Nickel ispresent incoastal and open ocean concentrations inthe range of0.1 to 6.0 mg/l, although the most common values are 

### 2 to3 mg/l. Marine animals contain up to400 mg/l, and marine plants contain up to 3,000 mg/l. The lethal 

### limitofnickel to some marine fish has been reported as low as 0.8 ppm. Concentrations of 13.1 mg/l have been reported tocause a 50 percent reduction ofthe photosynthetic activity inthe giant kelp (Macrocystic pyrifera) in

### 96 hours, and a low concentrationwas found to killoyster
Phosphorus (P) Phosphorus occurs innatural waters and inwastewaters in the form ofvarious types of phosphate. These forms are commonly classified intoorthophosphates, condensed phosphates (pyro-, meta-, and polyphosphorus), and organically bound phosphates. These may occur inthe soluble form, inparticles ofdetritus, or inthe bodies ofaquatic organisms. The various forms of phosphates findtheirway into wastewaters from a variety of industrial, residential, and commercial sources. Small amounts of certain condensedDRAFT phosphates areadded tosome water supplies inthe course of potable water treatment. Large quantities ofthe same compounds may be added when the water isused for laundering or other cleaning since these materials are major constituents ofmany commercial cleaning preparations. Phosphate coating ofmetals isanother major source of phosphates incertain industrial effluents. The increasing problem ofthe growth ofalgae instreams and lakes appears tobe associated with the increasing presence ofcertain dissolved nutrients, chief among which is phosphorus. Phosphorus isan element which isessential to the growth oforganisms and itcan often be the nutrient that limits the aquatic growth that a body ofwater can support. Ininstances where phosphorus isa growth limiting nutrient, the discharge of sewage, agricultural drainage, or certain industrial wastes to a receivingwater may stimulate the growth, innuisance quantities, of photosynthetic aquatic microorganisms and macroorganisms. The increase inorganic matter production by algae and plants in

### a lake undergoing eutrophication has ramifications throughout the aquatic ecosystem. Greater demand isplaced on the dissolved oxygen inthe water as the organic matter decomposes atthe termination ofthe lifecycles. Because ofthis process, the deeper waters ofthe lakemay become entirely depleted ofoxygen, thereby destroying fish habitats and leading tothe elimination ofdesirable species. The settling of particulatematter from the productive upper layers changes the character of the bottom mud, also leading tothe replacement ofcertain species by less desirable organisms. Ofgreat importance isthe fact that nutrients inadvertently introduced toa lake are, for themost part, trapped there and recycled inaccelerated biological processes. Consequently, the damage done toa lake ina relatively short time requires a many fold increase intime for recoveryof the lake. When a plant population isstimulated inproduction and attains a nuisance status, a large number ofassociated liabilities are immediately apparent. Dense populations of pond weeds make swimming dangerous. Boating and water skiingand sometimes fishing may be eliminated because of themass ofvegetation that serves as a physical impediment tosuch activities. Plant populations have been associated with stunted fish populations and with poor fishing. PlantDRAFT nuisances emit vilestenches, impart tastes and odors to water supplies, reduce the efficiency of industrial and municipal water treatment, impair aesthetic beauty, reduce or restrict resort trade, lower waterfront property values, cause skin rashes toman duringwater contact, and serve as a desired substrate and breeding ground for flies. Phosphorus inthe elemental form is particularly toxic, and subject tobioaccumulation inmuch the same way as mercury. Colloidal elemental phosphorus will poison marine fish (causing skin tissue breakdown and discoloration). Also, phosphorus iscapable of being concentrated and will accumulate inorgans and soft tissues. Experiments have shown thatmarine fishwill concentrate phosphorus from water containing as littleas 1 ug/l. Zinc (Zn) 

### -- Occurring abundantly inrocks and ores, zinc isreadily refined intoa stable pure metal and isused extensively as a metal, an alloy, and a platingmaterial. Inaddition, zinc salts are also used inpaint pigments, dyes, and insecticides. Many ofthese salts (for example, zinc chloride and zinc sulfate) are highly soluble inwater; hence, itisexpected that zinc might occur inmany industrial wastes. On the other hand, some zinc salts (zinc carbonate, zinc oxide, zinc sulfide) are insoluble inwater and, consequently, it isexpected that some zinc will precipitateand be removed readily inmany natural waters. Insoft water, concentrations ofzinc ranging from 0.1 to 1.0 mg/l have been reported tobe lethal to fish. Zinc is thought toexert itstoxic action by forming insoluble compounds with the mucous that covers the gills, by damage tothe gill epithelium, or possibly by acting as an internal poison. The sensitivityoffishto zinc varies with species, age, and condition, as well as with the physical and chemical characteristics ofthe water. Some acclimatization tothe presence ofthe zinc ispossible. It has also been observed that the effects ofzinc poisoning may not become apparent immediately so that fish removed from zinc-contaminated to zinc-free water may die as long as 

### 48 hours after the removal. The presence of copper inwater may increase the toxicityof zinc toaquatic organisms, while the presence ofcalcium or hardness may decrease the relativetoxicity.

### DRAFT 

### A complex relationship exists between zinc concentrations, dissolved oxygen, pH, 

### temperature, and calcium and magnesium concentrations. Prediction of harmful effects has been less than reliable and controlled studies have not been extensively documented. Concentrations of zinc in excess of 5 

### mg/l in public water varies widely. The major concern with zinc compounds in 

### marine waters isnot one of accute lethal effects, but 

### rather one of the long term sublethal effects of the metallic compounds and complexes. From the point of view of accute lethal effects, invertebrate marine animals seem to be the most sensitive organisms tested. A variety of freshwater plants tested manifested harmful symptoms atconcentrations of 10 mg/l. Zinc sulfate has also been found to be lethal tomany plants and itcould impair agricultural uses of the water. Pol1 utants Rejected The pollutants bromide (Br) and surfactants were analyzed in all samples collected. Neither pollutant was observed in significant quantities. Therefore, bromide (Br) and surfactants are rejected as pollutants for consideration in this study.

### DRAFT 

### SECTION VII TREATMENT AND CONTROL TECHNOLOGY



### INTRODUCTION Treatment and control technologies for potential pollutants discharged from steam electric power generating plants discharging to publicly-owned -treatmentworks (POTW's) are outlined in

### this section. In-process controls discussed include those techniques which are normally used by the industry or by industries employing similar processes. Such controls include process modifications, materials substitution, raw materials and products recovery, water conservation and wastewater reuse, and general good housekeeping practices. Wastewater effluents discharged to publicly-owned treatment facilities are sometimes treated by end-of-process physical or chemical systems toremove pollutants which can upset normal operation of the POTW. 

### Such treatment methods are numerous, but 

### they generally fall into one of three broad categories in accordance with

### their process objectives. These include pH 

### control, removal of dissolved materials, and separation of phases. Of the twenty-two plants surveyed only eight provide end-of-pipe treatment to their waste, before discharging ittoPOTW's. The extent of treatment applied varies in accordance with the local requirements for discharge limitations. Most of the plants use retention ponds to equalize the flow to POTWs. These ponds also serve as sedimentation basins for partial removal of suspended solids by gravity settlingand are sometimes equipped with skimming devices to remove floating oil. A 

### detailed description of end-of-pipe treatment techniques used is presented in Section V 

### of this report. A 

### properly designed and maintained wastewater control and treatment system isessential for an overall efficientwaste management program. In order to select and implement such a program, itis 

### necessary to evaluate the controls and the treatment techniques applicable in each case. The choice of any particular control strategy requires awareness of those factors affecting the quantity and nature of the wastewaters produced as well as their amenability to acceptance and treatment by publicly-owned treatment works.

### DRAFT



### END-OF-PIPE TREATMENT TECHNOLOGY 

### Treatment Technologies Available If a pollutant in awaste stream isnot acceptable for discharge to the publicly-owned treatment plant, end-of-pipe treatment must be provided to remove the pollutant or reduce itto allowable limits. Only a few existing plants discharging into POTW 

### provide end-of-pipe treatment. Yet, basic technology isavailable to remove nearly all of the pollutants produced by steam electric generating plants. This technology is shown in Tables VII-1 and VII-2. Table VII-1 listspotential dissolved matter removal methods and Table VII-2 provides a similar list of solid liquid separation processes. Most of the processes listed are in use in industrial or municipal water and wastewater treatment. End-of-pipe treatment presents difficulties for removing some of the chemicals used in power plants. These may include inhibitors, biocides, and chelating agents. For organic chemicals, activated carbon absorption is an available technology, but 

### the low concentration of the organics can make the process inefficient and costly. For some inorganics like chromates, ion exchange is similarly available, but 

### may not be economically feasible. For these pollutants, in-plant controls are probably the preferred control strategy. TREATMENT 

### - OF 

### MAJOR POLLUTANTS Available technology and efficiency of their removal for chosen pollutants are shown in Table VII-3. The following isa brief discussion of the problems associated with removal of pollutants from the power plant.

### END-OF-PIPE TREATMENT METHODS

Ch~mi calsor Process Efficiency of Advantages 

### , Limitations Required maintenance Demonstration status Method object1 ves equipment used requirements removal

Neutralization * pH adjustment. acid or base as usually towithin required. usually the range of6-9 sulfuric acid and lime 1-operates at ambient environment 2-well suited for

automatic control 3-high rate of reactions I-may cause scaling in tanks and conduits 2-produces

large quantities of sludge 3-may generate

toxic byproducts periodic removal of practiced extensively sludge by industry

Chemical reduction reduction of hexavalent chrorium to trivalent chromium sulfur dioxide, pH range of 99.7'6 sodium bisulfite, 2-3 sodium metabisulfite. ferrous salts periodic removal of sludge 1-operates at

ambient environment ?-well suited

to automatic control l-requires careful pH control 2-presence of

oxidants (oxygen. ferric ion) increases required dose of the reducing agent 3-Sulfur dl-

oxide is toxic and corrosive practiced extensively by industry

< u H Precipitation removal of ions lime, hydrogen optimum pH by forming sllght- sulfide, organic depends on the ly soluble salts precipitants, ions to be resoda ash moved copper-96.6% 1-operates at nickel-91.7% ambient enchromium-98.8: vironment zinc-99.7% 2-well suited to phosphate-93.6% automatic control 1-requi c a r e f u l r e s pH control 2-may require

more than a single step to remove a mixture of ions 3-presence of periodic removal of s1

udge practiced extensively by industry

chelating agents (1.e.. cyanide) Increases the solubi1ity of many metals Ion exchange remcval of ions by synthetic cation may require pH sorption on surface anion exchange adjustment of a sn;ld ,,,dt~1x cyanide-99"L chromium-98: copper-95; iron-100% I-operates at ambient environment 2-well suited to

automatic control 3-can be used to

recover valuable constituents periodic regeneration of resins 1-produces

wastewater effluent 2-resin is sub

Jected to attack by oxidizing agents (1.e. nitricacid) )-subjected to

clogging and fouling 4-costly to

operate used primarily inwater treatment operation for production of boiler feedwater cadmium-92% nickel-100% zinc-75%

process isnot highly developed for industrial use (except phenol extraction) Liquid/liquid removal of soluble

extraction organics or chemically charged pollutants phenol-999 chromium-99% nickel-99: zinc-99.. fluoride-68: immiscible solvents may require that may contain pH adjustment chelating agents 1-can be used to recover valuable constituentr 1-effluent required additional treatment 2-subjected to

chemical interference 3-solvent systemmay deteriorate with reoeate periodic regeneratio!~ of solvent

use

### END-OF-PIPE TREATMENT METHODS

Method
Disinfection

Adsorption 

# - Ch~micals or Process Efficiency of Advantages Limitations Required maintenance Demonstration status objectives equipment used requirements removal

destruction of chlorine, hypo- may require pH microorganisms chlorite salts, bdjustment phenol.pheno1 derivat4ves, ozone. salts of heavy metals. chlorine dioxide 1-operates at 1-may cause periodic loading ambient en- taste an4 of ci1emi:als vironment color pro2-well suited to b1 ems automatic control 2-disinfectant are compounds tox~c

removal of sorbable activated carbon, may require pH jepend on the I-high removal ef- I-waste re- periodic regcneracontaminants synthetic sorbents adjustment nature of pol- ficiency for trace quired pre- tion ofsorbent lutants and com- concentration treatment 'Jositlonof E-low energy re- Z-bed requ~red waste quirement regeneration 3-operates at am- 3-losses of

bient environment sorbent during regeneration Chemical oxidation destruction of cya- chlorine, hypochlo- H=9 5-10 99.62 nides ritesalts, ozone {first step) pH.8 (second step)

Distillation separation of dis- 1-multistage flash may require pH 100% solved matter by distillation adjustment evaporation of the Z-multiple-effect water long-tube verti- cal evaporation 3-submerged tube

evaporation 4-vapor compres-

siun

Reverse osmosis separation of dls- 1-tubular membrane solved matter by 2-hollow-filter filtration through modules a semipermeable 3-Spiral-wound flat membrane sheet membrane

Electrodialysis removal of dissolved polar compounds solute isexchanged between two liquids through a selective semipermeable membrane inresponse to differences inchemical potential between two liquids l-operate atam- bient temDeratur ?-well suited to

automatic l-require care- Periodic removal of .e ful pH con- sludge and loading trol of chemicals 2-may produce control poisonous gas 3-second reaction is slow 4-subjected to

chemical interference 1-produces high 1-high energy periodic cleaning to

qualitywater requirement remove scale 2-can be used to 2-may require

recover valu- pretreatment able constit- of waste uents 3-cause scalingof boilers and heat exchangers 4-may require

post treatment of water disinfection by chlorine is by practiced lndustry extensively

practiced extensively by industry

practiced extensively by industry

practiced only to a moderate extent by industry, primarily the submerged tube type unit

1-produces high 1 - l i m i t e d range periodic replacemerlt of very liriited use in

qualitywater ofoperating membrace industrial wastewater 2-can be used to temperatures treatment

recover valuable and concenconstituents trations 3-operates at am- 2-membrane is

bient tempera- susceptible ture tofouling by suspended solids or attack by many chemicals TOS-62-961 1-can be used to 1-membrane is penodic replacement of not practiced by recover and re- subjected to membranes and electrodes industry use valuable fouling by chemicals suspended~ 2-produces high solids

qualitywater 2-membrane and electrode are subjected to corrosion by chemicals- Method 

### END-OF-PIPE TREATMENT 

### METHODS

Ch~micals or Process object1 ves equipment used Efficiency of Advantages Limitations' reauirements removal Required maintenance Demonstrat~on status

Freezing separation of so- I-direct refrlgerlute from liqu~d atlon by crystallizing 2-indirect refrigthe solvent eration >99 5 1-produces high \-high energy periodic cleaning and re- unproven method in quality water requirement placement of filters and waste treatment Z-low operating 2-refrigerant screens application

temperature may be coninhibit5 taminated in corrosion the direct refrlgeratlon method

### SOLID/LIQUID SEPARATION SYSTEMS

Unit operation Process objectives Methods or Retention Chemicals Efficiency Advantages units used time used of removal Skimming removal of floating solids or liquid wastes from thewater 1-15 min none 70-902 1-simple tooperate 2-reduces down stream

treatment 3-high efficiency of

removal t0 coagulants, 15 mgll coagulant aids, pH adjustment Clarification

Flotatfon removal of suspended solids by settling I-high efficiency of removal inshort time and space separation of suspended solids by flotation followed by skimming 1-froth flotation 20-30 2-dispersed air min

flotation aluminum and 90-991 ferric salts, activated silicaorganic polymers 1-efficient process

3-dissolved air

flotation 4-gravity flotation 5-vacuum flotation Microstraining removal of suspended solids by passing the wastewater through a microscreen none 70-801 (23p) 50-601 1-no chemicals require- ment 2-low cost of operationand maintenance 3-high efficiency of

removal of large particles 1-low initial and

operating costs 2-small land requirement 3-no chemicals requirement 4-partial removal of

dissolved matter Filtration removal of suspended 1-multimedia bed NIA solids by filtration 2-mixed media bed through a bed ofsand and gravel none

1-protect down stream treatment equipment 2-inexpensive devices Screening

Thickening removal of large solid 1-coarse screens N/A matter by passing 2-bar screens through screens 3-communicating devices none

none depends on the nature of sludge 1-facilitates further sludge processing atminimum cost 2-flotation thifkeners

are more efficient than gravity thickeners concentration of 1-gravity thick- NIA sludge by removing ening water 2-air flotation thickening

1-high separation efficiency for difficult to remove solids 2-filter cake has a

low water content 3-suspended solids

content of fil- trate lslow 4-minimum maintenance Pressure filtration separation of solid from liquidby passing through a semipermeable membrane under pressure 1-3 hrs none to 50-75% moisture content

I-produces disposable product Heat drying reduce thewater content 1-flash drying N/A ofsludge 2-spray drying 3-rotary kiln

drying 4-multiple hearth

drying none to 8% moisture content

Total solid removal of 95% and above I-low capital installation and operating costs 2-unsensitivi ty to the chemical nature ofwaste 3-110 waste pretreatment isrequired Ultrafiltration separation ofmacro- molecules ofsus- pended matter from the waste bv filtration none

through*a semipermeable membrane under pressure

1-covered beds 2-uncovered beds filtration 1-2 day as filter l5-2O% 1-low costs Of construction, operation and maintenance Sandbed drying removal cfmoisture 

### .. from sludge by evaporation and drainace through sand. none

Vacuum filtration solid liquid separation by vacuum produces 30%solid infilter cake 1-highly efficient process none

1-small space requirement 2-simplicity in

operation Centrifugation liquid/solid separationby centrifugal force 1-disccentrifuge N/A 2-basket ceotrifuge 3-conveyor type

centrifuge none moisture IS reducedto 65-701

1-highly efficient process separation between emulsified oil and water 2-8 hour aluminum salts. iron salts, pH adjustment (3-4) Emulsion breaking

## SOLID/LIQUID SEPARATION SYSTEMS

Unit operation Limitation Energy Maintenance Demonstration requirement status Skimming 1-limited towastewater small containing floating matter periodic lubri- practiced extensively by cation industry

Clarification

Flotation I-high operating cost nominal periodic loading practiced extensively by of chemicals and industry removal of sludge 1-efficiency depends on nominal

the nature of the parroutine maintenance practiced extensively by of pumps and motors industry ticles surface

routingcleaning practiced only to a moderate of screens extent, primarily inmunicipal wastewater treatment plants Microstraining 1-may result inhigh head loss 2-low efficiency of

removal of small articles small

small Filtration 1-wastewater with high suspended solids content require pretreatment 2-high losses of head 3-produces wastewater 4-operation is cornlicatedand requires training routine main- practicedextensively primarily tenance of pumps inwater treatment plant

1-minor effect on

overall treatment 2-may result inhigh

hued loss small periodic cleaning practiced extensively by industry Screening

Thickening periodic cleaning practicedextensively lubrication by industry I-sensitive to flow

rate of both effluent and sludge removal small

small periodic cleaning not practiced by and replacement industry of filter Pressure filtration 1-short lifeof filter cloth 2-requires operating

personnel

Heat drying 1-costly process hlgh periodic cleaning rotary kilns are used by industry to small extent

Ultrafiltration 1-lir~ited range of nominal operating temperature 2-membrane is susceptible to attack by many chemicals 3-limited range of

applications 4-membrane can be

fouled by suspended solids routine maintenance used by industry ofpumps primarily to treat oilywaste

small periodic removal practiced extensively ofsludge by industry Sandbed 1-requires a large area of land 

### .

Vacuum filtration 1-hioh operating COSt 2 - f i l t r a t e may require further treatment r.ominal

nominal periodic cleaning practiced extensively and replacement by industry of filter media

Centrifugation Operating \ cost 2-may produce noise periodic lubrica- equipment for intion and cleaning dustrial wastewater treatment is under development

Emulsion I-requires segre- small breaking gation of oily waste from non oilywaste routine maintenance practicedextensively ofpumps and motors by industry and periodic re- moval ofsludge

### DRAFT

TREATMENT OF MAJOR POLLUTANTS Table 

### VII-3. Residua1concentration achievable (mgll)(1 7) 

### Pol1 utant Treatmentmethod Common DH Neutralization Clarification Flotation Fi1 tration Total suspended solids 1

# - 2

# - 3

# - S 

### ecific



# h Grease Skimming Gravityflotation Dissolvedairflotation Hexavalentchromium 1

# - Chemicalreduction Chromium (total

### ) 1

# - 2

# - Precipitation Ionexchange Iron 1

# - Precipitation Copper Precipitation Ionexchange Zinc Precipitation Ionexchange Chlorine 1

# - Dissipation Aeration Chemical reduction Below detectionlimits Be1ow detection 

### 1imits Below detection1 imi tsDRAFT

Total Dissolved Solids. Removal of total dissolved 

### -- solids (TDS) from wastewaters isone of the more difficult and more expensive waste treatment procedures. Where TDS resultfrom heavy metal or hardness ions, reduction can be achieved by chemical precipitation methods; however, where dissolved solids are present as sodium, calcium, or potassium compounds, then TDS reduction requires more specialized treatment, such as reverse osmosis, electrodialysis, distillation, and ionexchange. Total Suspended Solids. Suspended solids removal can be achieved by sedimentation and filtrationoperations. sedimentation-lagoons are commonly used at steam electric power plants. Some plants employed configured tanks. Tanks can be used where space limitations are important. Tanks constructed for solids removal usually have built-in facilities for continuous or intermittent sludge removal. Designs based on maximum flow anticipated can provide the best performance. Equalization can be provided to regulate flow. The retention time required isrelated tothe particlecharacteristics. 

### Oiland Grease. Certain preventative measures can be -- applied to prevent spillage of oil and the entrance ofoil intothe plant drainage system.' Flotation isefficient in removing emulsified oil and requires minimum space. It can be used without chemical addition, but demulsifiers and coagulants can improve performance insome cases. Whenever possible, primary separation facilities should 

### be employed to remove free oil and solids before the water enters the flotation unit. Multistage units are more effectivethan single-stage units. Partial recycle units are more effective than full-pressure units. Oil removal facilities including single-cell flotation can achieve effluent oil and grease levels from 10-20 mg/l, while multistage units can achieve 2-10 mg/l. Chromium. The most common method of chromium removal 

## -- ischemical reduction of hexavalent chromium tothe trivalent ionand subsequent chemical precipitation. The standard reduction technique isto lower the waste stream pH to 3 or below by addition of sulfuric acid, and toadd sulfur dioxide, sodium bisulfite (or metabisulfite or hydrosulfite), or ferrous sulfate as a reducing agent. Trivalent chromium isthen removed by precipitation with lime at pH 8.5-9.5. The residual of hexavalent chromium after the reduction step depends on the pH, retention time, and the concentration and type of reducing agent.DRAFT A process for chromate removal from cooling water has been recently developed. This isan electrochemical process whereby an electrical current isapplied to a consumable ironelectrode. The resulting ferrous ions react with the wastewater chromate inaccordance with the following equation:

Because of the alkaline pH both the iron and chromium precipitate as metal hydroxides and are subsequently removed ina clarifier. The produced ferric ion further enhances the coagulation and settling of suspended solids. Chromate residuals from this process have been reported to be less than 

### 0.05 ppm. Costs of treatment are claimed to be fairly low and the operation isautomatically controlled. The process isalso applicable for removal of other metals ions such as zinc, copper, nickel, tin, iron, etc. (16). Copper. Effluent concentrations of 0.5 mg/l can be consistently achieved by precipitationwith lime employing proper pH control and proper settler design and operation. The minimum solubility of the metal hydroxide is inthe range of pH 8.5-9.5. Ina power plant, copper can appear in thewastewater effluent as a result of corrosion of coppercontaining components of the necessary plant hydraulic systems. Normally, every practicable effort ismade, as a part of standard design and operating practice to reduce corrosion of plant components. Copper isnot usually used in construction ofonce-through boilers and consequently, is rarelyfound incorresponding spent cleaning solutions (12). Excessively stringent effluent limitations on copper may necessitate complete redesign and alteration of condenser cooling and other systems. A significant problem in achieving a low residual concentration ofcopper can result 

### ifcomplexing agents are present, especially cyanide and ammonia. Iron. Ingeneral, acidic and/or anaerobic conditions are necessary for appreciable concentrations of soluble iron to exist. "Complete" iron removal with lime addition, aeration, and settling followed by sand filtration has been reported. Existing technology iscapable of soluble iron removals to levelswell below 0.3 mg/l. Failure toachieve these levels would be the result of improper pH control. The minimum solubility of ferric hydroxide is between 

### 7 and 8 (12). Insome cases, apparently soluble ironmay actually be present as finely divided solids due to inefficient settling of ferric hydroxide. Polishing treatment such as rapid sand filters 

### will remove these solids. Ina power plant, iron,DRAFT

as with copper, can appear inthe wastewater effluent as a result ofcorrosion to iron-containing components of the necessary plant hydraulic systems. Normally, every practicable effort ismade, as a part of standard design and operating procedure, to reduce corrosion of plant components. Excessively stringent effluent limitations on iron, as with copper, may necessitate complete design and alterationof condenser cooling and other systems. Zinc. Lime addition for pH adjustment can result in precipitation of zinc hydroxide. Operational data indicate that levels below 1 mg/l zinc are readily obtainablewith lime precipitation. The use ofzinc can be minimized since other treatment chemicals are available to reduce corrosion inclosed cooling water cycle. Zinc removals have been reported for a range of industrial systems and, generally, treatment isnot for zinc alone. END-OF-PIPE TECHNOLOGY FOR MAJOR 

### -- WASTE STREAMS The regulations describe the various wastewater streams as low volume waste sources, ash transport water, metal cleaningwastes, boiler blowdown, and cooling system wastes. It isalso possible toclassifywastewater streams by their temporal distribution into continuous, periodic, and occasional. Continuous wastewater streams will have to be treated on a continuous basis. The main treatment criteria istherefore the rateof flow. Periodic wastewater streams will generally be treated on a batch basis and discharged at

### a controlled rate. The treatment criteria are therefore the volume of each batch, the frequency of occurrence, and the rate ofdischarge from treatment. The occasional waste streams are generally produced by outside conditions not relatedtothe production of electrical energy such as precipitation. Some waste streams such as cooling water are directly related tothe production of electrical energy and will not be discharged 

### ifthe plant isnot producing power. Others are relatedtothe cumulative amount of energy produced by the plant, but may be discharged at the time the plant is not inoperation. Metal cleaning wastes are an example of this type ofwaste.

### DRAFT Continuous Waste Streams. Continuous wastewater streams consist primarily of coolinq systemwastes, 

### - - 

### either of the once-through or the recirculating system blowdown type. None of the plants contacted in this study were found to discharge once-through cooling water to publicly-owned treatment facilities. Where such discharge occurs, consideration should be given to removing this discharge from the sanitary sewer system, since none of the possible pollutants in the cooling water will be removed by standard biological treatment and the large hydraulic loading will decrease the effectiveness of the POTW treatment process. Residual chlorine contained in once-through cooling water discharges can be removed by so-called "dechlorination" processes. Methods of dechlorination ,includeaddition of reducing chemicals, passage through fixed beds of activated carbon and aeration. Reducing chemicals include sulfur dioxide (SOZ), - 

### sodium bisulfite (NaHS03), and sodium sulfite (Na2S03). Of these agents, sodium bisulfite is most commonry used (19). 

### Granular activated carbon as adsorb chlorine compounds and is oxidized by it to carbon dioxide. Oxidizing chlorine compounds such as chlorine (C12), hypochlorous acid (HOCl), chlorine dioxide (~102)-and nitrogen trichloride (NC13) are sufficiently voiative to be removed by aeration (19).-Other active chlorine species are not as volatile and may not be removed. Data available to date do not indicate that heat discharged in this waste is a problem to a POTW. Closed cycle or recirculating cooling water system blowdown is discharged into POTWs by a number of plants. The discharge may be continuous or intermittent. Significant parameters of pollutants that may be found in cooling water blowdown may include chlorine, hypochlorous acid, sodium hypochlorite, phosphates, chromates, zinc compounds,organic biocides, dispersing agents, and depending on the constituents in the makeup water supply,various inorganic salts resulting from the concentration of those constituents and the necessity of maintaining the pH within certain limits. Pretreatment may be necessary if certain types of inhibitors and biocides are used as internal treatment in the cooling water system. These are likely to inhibit biological activity at the publicly-owned treatment facilities and will therefore have an adverse effect on the treatment operation. The extent of this effect will depend on the relative volumes of boiler blowdown and domestic wastewater. Organic compounds used as inhibitors, biocides, or dispersing agents are not likely to be degraded by secondary biological treatment and will therefore pass through the publicly-owned treatment facilities and be discharged to the receiving waters. Toxicity studies are being conducted with individual proprietary compounds in order to establish permissible levels of discharge.DRAFT End-of-pipe technology isavailable to remove most inorganic pollutants. Many inorganic pollutants are insoluble at alkaline pH, and can be removed by adding limeor another form of alkali. The degree of removal isa function of the solubilityofthe pollutant at high pH. Some specific pollutants such as chromium can be removed by ion exchange, but the ultimatedisposal ofthe spent regenerants presents problems. Periodic Wastes. Periodic wastes includewaste resulting from boilerand service water treatment, boiler blowdown (can be continous), ionexchange water treatment, water treatment evaporative blowdown, boiler and air heater cleaning, other equipment cleaning, laboratory and sampling streams, floor drainage, cooling tower basin cleaning, blowdown from recirculatingwet-scrubber air pollution control systems, and other relatively low volume streams. These include allthewastes that are classified as "ash transport" and "metal cleaning" wastes. For plants discharging wastes topublicly-owned treatment facilities, boiler blowdown isgenerally not a significant source of pollution. Water treatment wastes may or may not be significant depending on the source ofthewater and method of treatment. Since most plants discharging wastes to publicly-owned treatment facilities also obtain their water from the municipal water supply system, the wastes will consists of normal constituents ofthewater supply, plus any chemicals used inthe treatment process. 

### Ifthe treatment process ision exchange, thewastes will contain inorganic acids and alkalis. Combination ofwatest from anion and cation exchanges will generally result incombined waste stream that isacceptable tothe treatment plant. If the pH of the combinedwaste stream isoutside the range of 6.0 to9.0 normally acceptable tobiologically based treatment process, neutralization may be required. Evporation blowdown isusually high indissolved solids, but otherwise acceptable for discharge tothe publicly-owned treatment facilities. The dissolved solids consists primarily of concentrated constituents of the public water supply and do not have a-ny adverse effect on the treatment plant or the receiving water. Floor drains may be a significant source of pollution, with oil and grease as the most significant parameter. The regulations for direct discharge limitoil and grease for all low volume wastes taken collectively to 100 mg/l on any one day, and 30 mg/l average for 30 consecutive days, but local authorities may impose more severe limits. Most municipal pretreatment ordinances also limitoil and grease so that pretreatment may be required for removal of this pollutant.

### DRAFT 

### End-of-pipe technology is available and isused by some plants. The technology consists of gravity separators, either unassisted or assisted by flocculants and/or dissolved air flotation, followed if necessary by filtration. The technology is able to meet the desired standards ata minimal cost. However, to meet desired standards efficiently only those waste streams containing excessive oil and grease should be passed through the treatment unit. Metal Cleaning Wastes. The most significant of the periodic wastes in terms of their potential impact on the pub1icly-owned treatment facilities are metal cleaning wastes. Metal cleaning wastes are produced intermittently while units are shut down. The efficiency of electric power production depends largely on the efficiency of heat transfer between the combustion products and the boiler water. All metallic heat transfer surfaces have a tendency to either corrode or collect deposits. Both corrosion products and deposits reduce the efficiency of heat transfer and must therefore be removed periodically. There are two main types of cleaning operations: waterside and fireside. Waterside cleaning consists of cleaning the inside of tubes, and other boiler water passages. Due to the inaccessibility of these surfaces, the only practical and generally accepted method of cleaning is by chemical means. The cleaning typically proceeds in three stages: a bromate soak, an acid cleaning (usually inhibited hydrochloric acid), and finally a passivation stage. The total operation takes about two days and produces about five boiler volumes of wastes, with each stage consisting of a fill, drain, fill and rinse operation lasting about 1-112 112 to 2 

### hours. For multiunit plants, only one boiler is cleaned at any one time, so that the majority of the plant is operating during the cleaning cycle. Fireside cleaning ismore mechanical, consisting of high pressure nozzles directed against the surfaces to be cleaned. The cleaning solution often contains alkalis to dissolve oil, and grease and detergents to keep the removed material in colloidal suspension. Fireside cleaning isdone on both the boiler and the air preheater. Pollutants contained in the cleaning solutions consist of both the chemicals used in the cleaning solution and the material removed from the heat transfer surfaces. Tables VII-4 and VII-5 give ranges of composition for chemical cleaning and firesidecleaning wastes, respectively. These pollutants are generally not removed by biological secondary treatment and may have an adverse effect on the treatment process, depending on the ratio of metal cleaning wastes to total flow atthe publicly-owned treatment plant.

### DRAFT

Table VII-4.TYPICAL COMPOSITION OF BOILER CHEMICAL CLEANING 

### WASTES
Component Hydrochloric Acid Iron Copper Sodium Borate Ammonium Carbonate Ammonium Hydroxide Chromate Inhibitors Thiourea Ammonium Bifluoride Sodium Carbonate Amount, Ib.

plus small amounts of silica, phosphates, nickel, zinc, aluminum, titanium, manganese and magnesium. Size

### of unit Volume of wastes 500 MW 95,000 gal

Table VII-5.TYPICAL COMPOSITION OF BOILER FIRESIDE WASH 

### WASTE Component Suspended Solids Iron Copper 

### Nickel Zinc 

### Oil and 

### Grease Volume, gal/KW IGC 

### (once/year for each boiler) Concentration, mg/lDRAFT Options for process modifications for metal cleaning wastes are small. End-of-pipe technology isavailable for the removal of most of the pollutants resulting from metal cleaning operations. Basic technology for removing pollutants from the waste stream consists of retention, storage and combination of waste streams, raising the pH to precipitate metallic salts, and pH readjustment for discharge to public sewers. With the increased use of organic materials for cleaning solutions, the use of incineration inpower plant boilers has become a practical alternative for the disposal of chemical cleaning waste. One limitation on the use of incineration isthe need for a reserve boiler to incinerate the wastes. However, inthe vast majority of cases, power plants consist of at least two units, so that this limitation would only occur ina few instances. Further, power plants with only one boiler can store cleaning wastes inholding tanks and incinerate them when the cleaning operation is over. Since metal cleaning wastes are only rarely produced, (some plants clean their boiler only once every five years) many plants prefer to have them hauled off and treated by private contractors. Most of the expertise for treating cleaning wastes has been developed by the cleaning contractors who are generally being asked to include waste treatment and disposal as part of the cleaning contract. Ash Transport Water. Hydraulic systems for handling bottom ash are used primarily by coal-fired plants. The preliminary listingof plants discharging to publicly-owned treatment plants contain coal-fired plants. Hydraulic systems are used for fly ash removal, usually inconjunction with scrubbers for sulfur dioxide removal. Where scrubbers are part of the air pollutioncontrol system, provision has to be made for handling of the sludges resulting from the operation. This sludge isnot suitable for disposal to the public sewer system. Air Pollution Control Wastes. There is normally no liquid effluent fromsulfur dioxide scrubbers. The water within the system isusually recycled as much as possible by dewatering the sludge to a filter cake. Some water leaves the system as steam with the gaseous emissions and some water becomes entrained inthe sludge cake, but the objective of good operation istominimize the amount of water inthe sludge cake. The water retained inthe sludge cake is sufficient tomeet the requirements for system blowdown.

### DRAFT


### Occassional Wastes. Occassional wastes are those that are caused by contamination of stormwater runoff by materials stored 

### on the plant site. The principal type of contaminated stormwater is coal pile runoff, and this is restricted to coal fired plants. A 

### significant number of urban plants have been converted from coal to oil fired, but 

### still retain the coal capability and may keep a coal reserve stored on the site. The coal reserve may become a significant source of pollution due to the interaction of water and airwith some of the impurities in the coal, notably iron and sulfur. No plants discharging coal pile runoff to publicly-owned treatment facilities were uncovered during the industry survey. A 

### type of process modification would be to cover the coal pilewith plastic sheeting the way a baseball infield is covered in the rain. This would eliminate the formation of waste stream. Alternately, the waste stream, once produced, can be neutralized with lime as an end-of-pipe treatment, and any suspended solids allowed to settle. This practice is common in related industries. WATER MANAGEMENT 

### The varied uses that are made of water in a power plant and the wide range of water quality required for those uses present this industry with an unusual opportunity for water management and wastewater reuse. Since power plants dispose a great portion of their water by evaporation, itis feasible that such plants can be operated with zero water discharge. Indeed, many plants developed water management programs that make use of all the wastewater streams produced by recycling them into unit processes which tolerate lower water quality (e.g. ash handling). However, to develop and implement a water management program of no discharge, itisnecessary to evaluate the water requirement of each segment of the process as well as the specific factors which affect individual plant water needs. Such factors include the nature of the raw water source, the location of the plant and its climatic environment, water availability and water cost, and the local requirement for effluent limitations.

### DRAFT The chemical composition of the raw water source affects the magnitude of the discharge from almost every segment of the process. To deionize water with high dissolved solids content to produce boiler feedwater, the ion exchange system must be regenerated more often. Further, highly dissolved solids contents would also lower the concentration cycle of closed-loop recirculations cooling system, and therefore would increase the blowdown from these systems. In areas of excessive rainfall closed-loop recirculating systems would have to be bled more often to prevent the systems from overflowing and may indeed be difficult to operate. In areas where the rate of evaporation is greater than the rate of precipitation, such systems would require makeup water to maintain the flow. Water availability and costwould have an impact on the plant incentive to conserve water. The extent of wastewater treatment provided 

### by the plant would depend on how stringent the local requirement for effluent limitations are. IN-PLANT CONTROL TECHNIQUES Control of wastewater effluents produced by the industry can be best achieved by incorporating in-process changes capable of reducing the volume ofwastewater discharged, or reducing the amount of pollutants in the discharge. Such changes can be classified under one of the following categories:
Process modifications; e 

### Materials substitution; o 

### Water conservation and wastewater reuse; @ 

### Raw materials and product recovery; and o 

### Good housekeeping practices. Application of such techniques can result in multiple benefits, including savings in construction and operation costs of on-sitewastewater treatment plants and in sewer surcharge and other charges associated with the use of publicly-owned treatment facilities.
In power generating plants there are theoretical opportunities for a number of such control measures. Practically, the opportunities are limited by the cost of any major process change under "retrofit" conditions, that is, conditions which require substantial mechanical and structural changes to an existing plant. Process Modifications A great number of process modifications are available to reduce the quantities ofwastewater from a power generating plant, or to eliminate it altogether. In order to present

### DRAFT 

### these potential modifications in

### an orderly manner, this section has been further divided into subsections, each dealing with an individual wastewater stream. Once Through Cooling Water. Switching from a oncethrough to a closed or open recirculating cooling system would greatly reduce the amount of wastewater discharged. This can be shown by balancing the quantity of heat rejected by 

### each of the systems. For a once-through cooling system this quantity isequal to the product of the water flow times the condenser temperature rise. -For a recirculating system itcan be assumed that all the heat is rejected by evaporation. Neglecting drift and windage losses the following equation can be written:

where B/F 

### is the ratio of the blowdown from a recirculating system to the discharge from once-through cooling system, 

# ATisthe condenser temperature rise, q 

### is the amount of

heat required to evaporate a unit weight of water, and C 

### is the concentration cycle. The concentration cycle isdefined as the ratio of the concentration of a limiting parameter in the makeup water to that in

### blowdown. For a typical condenser temperature rise of 10°C and for q 

### equal to 555 kcallliter of water, even at a concentration cycle of 2, 

### approximately 98 

### percent reduction in the volume of wastewater produced would be achieved. This reduction in cooling water consumption can alsobe classified under water conservation and wastewater reuse category. Switching from once-through to a recirculating cooling syste, however, is costly and not always feasible. Power plants-contacted in this study that utilize once-through systems discharge the effluent directly to surfacewater. Such discharges are subjected to EPA 

### regulations which limit the temperature and the chlorine concentration of waste effluents to be discharged to surfacewater. Excess total residual chlorine concentration in

### effluents from once-through cooling system can be minimized by monitoring and controlling free available chlorine concentrations in the discharge stream. A 

### further technique to reduce total residual chlorine discharged is to chlorinate during periods of low condenser flow. Alternatively, the chlorine input 

### to once-through cooling water can be reduced to a level below the concentration required for complete fouling control. Any biological growth which may result would be removed by mechanical means (12). 

### This approach however, is limited by 

### the configuration of the process piping and structures involved atany plant.

### DRAFT



### Closed Condenser CoolingSystem Blowdowns. Although the volume of recirculating cooling system blowdown is considerably smaller than the amount of wastewater discharged from a once-through system, itisalso significantlymore polluted. The effluent contains a higher dissolved solids concentration due to the evaporation of a large portion of the cooling water. In addition, chemicals added to inhibit scale formation, corrosion, and fouling would also be present in

### the blowdown water. Blowdown from a recirculating cooling system can be disposed of by evaporation. In warm, dry climates, and where land costs are relatively low, such as in the southwest, blowdown streams can be collected in ponds and allowed to evaporate. Such ponds areusually lined with impervious material such as clay or plastic toprevent water infiltration and subsequent pollution of the groundwater aquifer (12). The 

### residual chlorine concentration in blowdown streams discharged toPOTW's can be controlled. This can be achieved by one of the following methods: Regulation through feedback instrumentation; Splitting the condenser effluent into two streams and chlorinating one at a time;

o 

### Reducing the length of the chlorination period;

@ 

### Substituting ozonation for chlorination. A number of advantages of ozonation over chlorination for the disinfecting of water have been recently cited. These advantages can be summarized as follows: 1)ozone neither increases the inorganic salt content nor produces pollutants afterreactions; 2) 

### ozone does not impart taste, color, or smell to the treated water; 3) 

### ozone is a much more powerful disinfectant than chlorine; 4) 

### ozone does not have any known harmful effect on aquatic life; and 5) 

### ozone does not have undesirable residual effects as it

### readily breaks down into oxygen. Chlorination, on the other hand, isnow being questioned by health authoritieswho must meet increasingly stringent bacteriological and waste discharge requirements. An 

### increased chlorine dosage which may provide satisfactory disinfection requirements may alsobe responsible forDRAFT
release of an excessive amount of pollutingmaterial to the aquatic environment. Current reports show that even trace amounts of chlorine are harmful to aquatic life (12). Water Treatment Wastes. Substitution of reverse osmosis or electrodialysis for ionexchanqe to produce boiler feed water 

### will-greatly reduce thewdischargefrom this section ofthe process. However, the technical feasibility of the reverse osmosis process is limited by the chemical characteristics ofthe raw water source and by economics, and for some plants polishing the product water by ion exchange 

### will still be necessary, depending on the boiler operating pressure. 

### A substantial reduction 

### inwastewater can also be achieved by preparing boiler feed water ina combined system consisting of the hot lime and the ion exchange processes (12). The raw water would be initiallysoftened by the hot lime process to remove a portionof the dissolved matter and then deionized inan ionexchange system. Because of the reduced dissolved matter load on the ion exchanges the system would have to be regenerated less frequently, and consequently, would generate less wastewater. Combined systems consisting of hot lime and zeolite deionization processes are used by plants 9369, 7116, and 

### 6387. Ash HandlingWastes. Ash handling isthe conveyance ofthe accumulated bottom and fly ash combustion solidwaste product toa disposal system. This isaccomplished by dry orwet processes. Inthe dry process the ash istransported to the disposal area by pressurized air, vacuum, or mechanical means. Dry ash handling systems do not generate wastewater and may allow a credit for the sale of the ash for itsmetal content. Bottom ash from oil fired furnace, for example, can be sold for itsvanadium content. The wet process can be either open or closed-loop systems. Inthe closed-loop system the ash isslurried inwater and conveyed to a clarifierwhere settling occurs. The clarified overflow from the settling pond isreturned to theboiler. The closed-loop ash handling system does not generate wastewater except inareas of excessive rainfall where the system must be periodically bled. Insuch cases the blowdown must be treated ina separate system to remove metal ion by precipitationand suspended solids by clarification. In areas where the rateof evaporation ishigher than the rate of precipitation, evaporation losses from closed-loop ash handling systems can be supplemented withwastewater from other unit processes such as cooling tower blowdown. Open-loop ash handling systems are a source forwastewater

### DRAFT


### sincethe transporting water is used but 

### once to convey the ash to the settling ponds. This wastewater source can be eliminated by switching todry or closed-loop type systems. Open-loop ash handling systems should be avoided when possible as the effluent from the ash pond may require additional treatment before itcan be discharged. Coal Pile Runoff. The extent of contamination of coal 

### -- pile runoff can be reduced by properly constructing the coal storage area. Coal piles can be sprayed with tar or covered with plastic sheeting to seal the surface to water infiltration A 

### drainage system should be constructed to collect the most polluted portion of the storm. In areas where the rate of evaporation ishigher than the rate of precipitation runoff can be disposed of by evaporation in ponds. Alternatively, coal pile drainage can be used in processes which tolerate low quality waters such as ash handling systems. If the plant is located near amine such water can be used in the coal washers toremove mineral matter. Diversion of this waste to ash ponds was also considered. However, because of the low pH 

### of such wastes, coal ash can be leached by the water resulting in the formation of additional waterborne pol1 utants. Air Pollution Control Scrubbing Devices. The nonrecovery scrubbing process for SO2 removal from flue gas is also a sourc-e of wastewater as the system may be periodically bled to remove spent solvent. This is a closed-loop type system employing recycled lime scrubbing liquor. The process requires makeup water for saturating the boiler gases. Changing to SO2 

### recovery systems would reduce the discharge from this part-of the process as well as allow a credit for the sale of recovered sulfur dioxide or other sulfur products. Table VII-6 

### lists some of the SO2 recovery processes currently available. It

### should be emphasiled, however, that some of the listed processes have reached only the pilot plant stage of their development and cost estimates for their installation and operation are somewhat higher than those for the nonrecovery processes. Material Substitution The blowdown from a recirculating cooling system can be reduced by increasing the concentration cycle. This can be achieved by substituting scale-forming ions with

### more soluble ions, or by using sequestering agents such as polyolesters and phosphonates to prevent deposition of precipitated solid phases. These dispersing agents, however, become pollutants in the blowdown water.Table VII-6. RECOVERY PROCESSES FOR FLUE GAS DESULFURIZATIONSYSTEMS
Process 

### 1. Doublealkali system



### 2. Chemilbau system

Hydrogen sul

### fi te system

Wellman-Lord systern

Cat-Ox 

### -sys

### tern

Shell flue

### gas system Mode ofSO2 

### - Sorbent System Removal Sulfur Recovery Product Aqueous solutionofChemical Precipitationof Calciumsulfate Sodium hydroxide, absorption dissolved sulfur Calciumsulfi te Sodium sulfate, & oxides with sodium b i s u l f i t e CA(OH)2 

### - Fluidizedbed of Catalytic oxidationThermal stripping Sulfur, liquid activatedcarbon to

### ~c04 and Fhysical absorption

solutionof sodium Chemical ci trate, citric absorption acidand sodium thiosulfate Aqueous solution Chemical ofsodium sulfate absorption and sodium bisulfite Catalytic oxidationof SO2 toSO3 with 02-at 

### 850~~ (vanadiumoxide) Abed

### ofcupric Oxidationto oxide supported by cupric sulfate activated a

### 1umina with hydrogenat SO2 1000°F and catalytic reduction with H2S - Precipitationof Sulfur dissolved sulfur withH2S - Thermal Sulfur regeneration by vacuum and catalytic reduction with natural gas 

### 78%sulfuricacid

Concentrated S02 

### -

### DRAFT


### Lime softening of cooling water makeup prior to its introduction into the system would also increase the concentration cycle, though itmay be costly because of large volumes of water requiring treatment. Installation of plastic or plastic-coated system components would reduce the extent of treatment of cooling water makeup. Plasticexhibits considerable resistance to corrosion and erosion. Many new installations using cooling towers employ plastic. Where publicly-owned treatment plants containing a tertiary step are used, phosphate and nitrate based corrosion inhibitors could be substituted for chromates as these pollutants are removed by a tertiary treatment step. Chromate-based compounds can also be substituted by a re~ently~developed synthetic organic corrosion inhibitorwhich isnot as toxic as chromate tomicroorganisms. The synthetic organic compound reduces both scaling and fouling as well as inhibits corrosion (12). Film-forming sulfophosphated organic corrosion inhibitor has also been developed. The substance is effective in both fresh and saltywater, and isalso considerably less toxic than chromate (12). To reduce the amount of metals in

### wastewater from cooling system blowdown and from chemical cleaning operations, boilers and condenser cooling systems could be constructed of non-polluting materials. Tubes and piping could be made of 

### special alloymetals or coated so as toreduce corrosion and scaling, but 

### this can be prohibitively costly. Cooling towers can be constructed out of concrete and ceramic materials and thus reduce the need for additives to the cooling water system. Pollutants contained in fireside wash can be modified by switching fuels. The switch from coal to low-sulfur oil isan example of such modification. Switching to low sulfur fuels can also eliminate the need for airpollution control devices. Switching to gaseous and liquid fuels eliminates the problems of ash disposal and coal pile runoff waters. Water Conservation and Wastewater Reuse Different water uses in the plant require water of widely varying quality. These range from the almost zero solids requirements for boiler feedwater makeup to the almost unlimited solids allowed for ash transport water or scrubber water supply. Consequently, the wastewater produced in the plant also vary widely in quality. This opens many opportunities forwastewater reuse.DRAFT Cooling system blowdown can be reused for ash transport or as scrubber water supply. Boiler blowdown water isusually better than the feed water supply and can be reused in the plant for other purposes. Boiler blowdown can be reduced by installing a heat recovery system. Insuch a system the blowdown isdischarged intoa flash tank operating ata lower pressure than the boiler pressure. Because of the reduced pressure a portion of the blowdown water evaporates toform low pressure steam which can be condensed and reused as boiler feedwater. The reduction inblowdown that can be achieved by this method depends on the pressure difference between the boiler and the flush tank. The use of a heat recovery system for boiler blowdown 

### will also increase the thermal efficiency of the plant. Spent regenerants and rinses from the ion exchange system are also of a quality suitable for many purposes, where dissolved solids are not a limiting factor. Some of the periodicwaste streams could be recycled or reused ifsufficient storage isavailable to hold these streams until needed. Metal cleaning wastes after pretreatment or treatment could be used for low qualitywater uses such as ash transport or scrubber supply. However, the cost of storage may make such reuse prohibited. Materials Recovery Nearly all chromates, used as corrosion inhibitors, can be recovered using properly designed ion-exchange beds. Regenerant streams from the beds, which contain a relatively high c,oncentration of chromate, can be returned to the cooling system as a usable corrosion inhibitor. Plants which soften boiler feedwater with lime can reuse lime sludge in their air pollution control system for SO2 - removal. Recoverying-heatfrom boiler blowdown would reduce thermal discharges from this segment ofthe process, as well as increase the thermal efficienty of the process. Recycling of flyash back tothe furnace can be employed to increase thermal efficiency by burning products of incomplete combustion. It isalso possible to recover vanadium from oil ash with high vanadium content. Spent regenerants from ion exchange system can be used where the quality of the acid and alkaline solutions is not critical. For example, the acid solutions can be used inrecirculating cooling system tomaintain the pH of thewater below saturation. 

### Air pollution control devices, on the other hand, may require an alkaline source ofwater.

### DRAFT



### Good.Housekeeping Practices There are numerous alternativemethods ranging from taking precautionary measures against spi11s of chemical solutions oroil topump sealing toprevent leaks. Facilities should be constructed sothat oil and grease contaminated water will not drain directly into other water systems or be diluted by rainfall runoff. Cleaning up 

### oil spills, maintaining equipment tominimize leaks, and supporting an effective surveillanceprogram wi11 

### a1so minimize contamination of wastewater effluents. Controlling additions of chemicals towaters used in the various units of the process would reduce their concentrations in the effluents streams. Flow of water into the plant should be regulated in

### accordance with

### production rate. SUMMARY A 

### variety of wastewater control and treatment technologies are available for the steam electricpower industry. Since the water needs, and the requirements forwastewater discharge are specific to each individual plant, each control and treatment system must be developed in accordance with the individual plant requirement and should be integrated in a comprehensive water management program. Special consideration should be given to in-process control techniques. Often, such technique can be found easy and inexpensive to implement and yet, they can result in substantial reduction in water consumption and wastewater discharge.DRAFT SECTION 

### VIII

COST, ENERGY, AND OTHER NONNATER QUALITY ASPECTS

INTRODUCTION This section discusses cost estimates for control and treatment technologies described inprevious sections, energy requirements for these technologies, and nonwater quality related aspects such as reuse ofwater within the plant. Ultimate disposal of brines and sludges, effect of 

### 1and avai1 abi1

### ity, user charges and pol1utants 

### 1imitations imposed by POTWs and other factors relating tothe steam electric power generating point source category are also discussed inthis Section. Costs are developed ingreater detail for those waste sources which potentially are discharged to POTWs and are therefore subject to pretreatment requirements. These include the following:

o Low Volume Wastes



### o Metal Cleaning Wastes



### a Cooling Tower Blowdown



### a Area Runoff and Ash Pond Discharges Other waste streams such as ash transport water, boiler blowdown, and once-through coolingwater are provided in the latter part of this section. The raw waste characteristics for discharges to POTWs are similar tothose for direct discharge tosurface water, as covered inthe Development Document for this industrial category.DRAFT For most power plantwastes, the pretreatment for discharge to POTW involves control ofthree parameters of pollution, pH, suspended solids, and oil and grease. Control of pH neutralizes any undesirable acidity or a1kalinity. Treatment for suspended solids then removes suspended metals as well as other suspended material. Oil and grease isseparated from the water phase ofthe low volume wastes and skimmed off. COST REFERENCES -- AND

A RATIONALE Cost information contained inthis reportwas obtained from the following sources:

o Engineering estimates based on published cost data for equipment, construction, and installation;

o Estimates and guidelines for estimating contained inthe Development Document for steam electric industry discharges to surface water and the other EPA documents;

o Quotationsfor materials and supplies pub1ished incurrent tradejournals.

o Cost.data obtained as a result ofdirect inquiry to industry for data on actual installations. Interest Rates and Equity Finance Charges Capital investment cost estimates for this study have been based on 10 percent capital cost which represents a composite value for either interest rate paid or the required return on.investment. Time Basis for Cost Adjustment 

### ---- All estimated costs are taken from July, 1976 prices or where necessary adjusted tothis time basis using the ENR construction cost index of 2413 (July 1, 1976). Useful Service Life -- The useful service lifeofallwastewater treatment and disposal facilities isa function of the process involved, the quality ofthe equipment and design, its use patterns, the quality of maintenance and several other factors. Whereas individual companies often use service 1

### ives based on actual local experience, for the purpose of internal authorization, the Internal Revenue Service providesDRAFT guidelinefor tax computational purposes which are intended to reflectapproximate average 1

### i feexperience. The following useful service life values were chosen'for use inthis report from the literature, discussions with representatives of industry, and IRS guide1ines data:

0 General process equipment 10years e Buildings, sewers, ponds, etc. 20 years e Material handling equipment and 

### 5 years vehicles Depreciation The allocation of the cost ofcapital assets such as treatment and disposal equipment less salvage (ifany) over the estimated useful service lifeofthe unit or facility in a systematic and rational manner as a non-cash expense is termed depreciation. For IRS tax purposes and to make suitable financial allowance for equipment replacement several types of depreciation are used. Simple straightline depreciationwas used as the basis ofcalculations inthis report. Capital Costs Capital costs have been defined for this study as all initial out-of-pocket cash expenditures for provision of wastewater treatment and disposal facilities. These costs will include research, development, and feasibility studies necessary to characterize and design the facilities land and site preparation costs when applicable, equipment, construction, installation, and start-up costs, costs of buildings, services and engineering (allocatedwhere necessary), contractor profits and contingency costs 

### ifsuch exist. Annual Capital Costs Most capital costs are accrued during the year or two prior toactual use of the facility. This present worth sum can be converted toequivalent uniform annual disbursements over the lifeof the facility by utilizing the Capital Recovery Factor Method: UniformAnnual Disbursement = where P = present value (capital expenditure)

## , i = interest rate, 

### %/I03 n = useful life inyearsDRAFT Operating Expenses Annual costs ofoperating pretreatment facilities include labor, supervision, materials, maintenance, taxes, .insurance, and power and energy. Operating costs combined with annualized capital costs give total costs for pretreatment operations. Rationale for Model Plants Plant costs are estimated for model plants rather than for any actual plant. Model plants are defined tohave sizes of 25 

### MW and 

### 500 MW capacity, which are representativeof large and small-sized operation. Definition - of Levels - ofTreatment and Control Costs are developed for various types and levels oftechnology: Minimum 

### (A - - or basic level). That level oftechnology which isequalled or exceeded by most or all ofthe involved plants. Usually, money for this treatment level has already been spent (inthe case of capital investment) or isbeing spent (inthe case ofoperating and overall costs). B,C,D--Levels. Successively greater degrees oftreatment with respect tocritical pollutant parameters. Two ormore a1ternative treatments are developed when applicable. Basis for Pretreatment Costs Indevelopment ofcost estimates found inTables VIII-1, VIII-2, VIII-4, and VIII-5, it isassumed that only the following wastewater effluents are discharged to POTWs and may, therefore, require pretreatment.

o Low Volume Wastes o Metal Cleaning Wastes CoolingTower Blowdown o Area Runoff and Ash Pond Discharges 0 Low volume wastes include ion-exchange regenerants, spills, leaks, air pollution control system bleed offs, area washdowns, and other miscellaneous wastewater streams. Metal cleaning wastes include tube and fireside boiler cleaning products, as well as air cleaner wastes.DRAFT
Area runoff includes rainwater runoff from coal piles. Ash pond overflows and blowdowns are designated as discharges. Costs have been addressed separately for the following wastes: Ash Transport Water Boi1 er Blowdown Reasons for addressing these sources of wastes separately are discussed indetail inSection 

### VII, but are also discussed briefly below. Ash transport water from coal-fired plants isgenerally recirculated after sedimentation, and the purpose of sedimentation is process rather than pollution control. Overflows from ash ponds are included inthe wastewater for pretreatment. Boiler blowdown can be, and sometimes is, discharged to POTW without pretreatment. Incan be handled at the combined plantwithout incremental costs.

No plant contacted inthis study was found to discharge once-through cooling water to a POTW. Therefore, costs are not generated for pretreatment requirements. Cost Variances The effects of age, location, and size on costs for treatment and control have been considered and are inthe body of this section. COSTS FOR PRETREATMENT Waste types covered inthis subsection include low volume wastes, metal cleaning wastes, cooling tower blowdown, area runoff and ash pond discharge. Since the wasteload differs depending on the fuel source used, cost estimates for pretreatment of wastewater effluents from steam electric plants have been divided intothose plants burning gas or oil and those using coal. 

### Oil and Gas Fired Plants 

## --- Oil and gas-fired plants probably 

### will have no ash pond discharge, no air pollution control wastewater, or coal pile runoff. Therefore, these plants have essentially ion-exchangeregenerants, miscellaneous low volume wastes, cooling tower blowdown and metal cleaning wastes. Estimatedwastewater volumes inliterslday (GPD) for the plant sizes given are: 25 

### MW Plant 500 

### MW Plant

@ Low Volume Wastes Ion-exchange re generants 11,400(3000) 454,000(120,000) Miscellaneous 3,800(1000) 151,400( 40,000)

0 Metal Cleaning Wastes 380

### ( 100) 10,200( 2,700)

@ Cooling Tower 

### Bl owdown 94,600(25,000) 1,892,000(500,000) 

### The low volume wastes contain primarily acids and/or bases and perhaps some oil. The metal cleaning wastes contain acids, bases, metals, oil and grease, and suspended solids. Cooling tower blowdown may contain chromates, chlorine, chlorinated phenols, mercury, phosphate, zinc and many other additives commonly used incooling tower systems. For purposes of cost analysis, however, cooling tower blowdown isassumed tocontain only free chlorine (chlorine is the most commonly reported biocide used). Defined Pretreatment Levels The raw wastes requiring pretreatment prior to POTW disposal are similar tothose described inthe Development Document for direct dischargers, and use has been made of the data on wastewater volumes, waste loads and other information contained therein. The minimum pretreatment level, defined as Level A, consists of that level of technology which is equalled or exceeded by most or all of the existing plants. This level involves some flow equalization and combining of wastes toget the benefit of some neutralizing and diluting effects. Expenditures, both capital and operating are small.

### DRAFT

WASTEWATER TREATMENT COSTSAND RESULTING WASTE-LOAD CHARACTERISTICS FOR fYPlCAL PLANT

s"ecATEGoRY 

### Oil orGas Fired Plant
PLANTSIZE 

### 25 MW 

# ----- 

# ---------- PLANTAGE

# -. YEARS PLANTLOCATION

COSTS OF TREATMENT TO ATTAINSPECIFIED LEVELS

RLSULTIWI WASTE-LOAD CHARACTERISTICS COST CATE00RY

TOTAL INVESTED CAPITAL

ANNUAL CAPITALRECOVERY ANNUAL OPERATtNOAND YAlHTENANCE COSTS (EXCLUDINBEIUEROYAND POWER) ANNUAL ENLRIY AWDPOWER COSTS
TOTALANNUALCOSTS 

### t 

## [ COSTS[#I Mi

### 1s/KWH* 

# 1 0.008 

## 1 0.097 

# 1 0.124 

# 1 0.186

# 1 *Plant operating atfull capacity and 7500 hrs/yr. cosss(U 10 ATTAINLEVEL

I

PARAMETER A 

### 10,000 $1,600

Small Small 1,600

,(a TSS 

### Fe



### (a)Low 

### volume and metal cleaningwastes combined (b) 

### Cooling Tower Blowdown 

### NOTE: 

### TSS, Fe, and Cu, 

### raw wastes concentrationsestimated fromTableA-V-20 of

### Development Document 

### EPA44011-74029 a (12) A 

# 1 8 C D 

# 1 E j CONCENTRATION (mg/l) (~)nl



### ,Oil & 

### Grease

(b) 

### Free CL?



### Level 

### A

# - Level B

# -

Level 

### C

# - Level 

### D

# - B 

### 50,000 '



### 8,150 10,000

Small 18,150

RAW(UNTREATED)



### 300 

### 200

. . 

### Flow Equalization Equalization of 

### low volume wastes, followed by 

### neutralization 

### topH 6-9, skimming of surfaceoil. Metal cleaningwastes combined 

### withlo&volumewastes and neutralized without sludgeremoval. Same asLevel B 

### except metal cleaningwastes neutralized, clarified with 

### sludgeremoval and discharged. Equalization, pH ad.justment, oil skimming, clarification, reacidification. Cooling tower blowdown treated

### withsulfi 

### te. AFTER TRLATYENTTO LEVEL



## ----

0.5 C 

### 60,000

9,760 13,000 500 23,260

300 200



# ----

0.5 D 

### 120,000

19,500 15,000 500 35,000

300 200 E



### 100 0.5 100

< 

### 1.0 <I00 <l.O

< 

### 100 0.5 <I00 0.0

### DRAFT TABLE 

### VIII-2

WASTEWATER TREATMENT COSTSANDRESULTING WASTE-LOAD CHARACTERISTICS FOR TYPICALPLANT

PLANTSIZE 

### 500

### MW 

# ---- 

# ------------ PLANTAGE

## . YEARS PLANT LOCATION

COSTS OF TREATUENT TO ATTAINSPECIFIED LEVELS

COST CATEOOAY cosrs<U TOATTAINLEVEL

TOTAL INVESTED CAPITAL
ANNUAL CAPITAL RECOVERY ANNUAL OPERATINOAH0 MAINTENANCE COSTS (EXCLUDIWOESEROYANDPOWER) ANNUALENLROYAND POWER COSTS

RESULTII(0 WASTE-LOAD CHARACTERISTICS A 

# 1 8 

# 1 C 

# 1 0 

# 1 E I

TOTAL ANNUALCOSTS 

### 80,000 13,000 

### 1 Small

(a)

## Lowvolume

### andmetal 

### cleaning

### wastes combined (b) 

### Cooling

## TowerBlowdown 

## NOTE: TSS,Fe,

### and

### Cu,

## rawwastes concentrationsestimated from

## TableA-V-20 

### ofDevelopmentDocument

## EPA 440/1-74029

### a (12) 

## Level A

# - Flow

### Equalization 

## Level B

# - Equalization of 

## lowvolumewastes, followed by 

### neutralization to

### pH 6-9,

### skimmingofsurface

### oil. Metal 

### cleaning

### wastes combined 

### with 

### low

### volume

### wastes and

### neutralizedwithout 

### sludgeremoval. 

## Level C

# - SameasLevel B

### exceptmetal cleaning

### wastes neutralized,clarified 

## with sludge

### removal anddischarged. Level 

## D

# - Equalization,

### pH adjustment,oil 

### skimming,clarification,

### reacidification. 

## Cooling towerblowdown treated

### with sulfi

### te. 13,000

PARAMETER 

### (a) TSS 

### Fe 

## Cu 

## PH 

### Oil & 

### Grease (b) 

### FreeCL7 

### 700,000 114,000 130,000 3,000 300,000

48,800 60,000

1,000

COSTS4. 

### Mi1

### s/KWH* 109,800 300.000 48,800 80,000

2,000

*Plantoperating 

### atfull capacity

### and 7500hrs/yr. 0.035

i CONCENTRATION (ng/l) (ppn) 

### 0.004 130,800

RAWtunTREATED)



### 300 200 

### 1

## .o


# -----

----- 0.5 0.029 2479000 0.065 J

AFTER TREATMENT TOLEVEL A 

### 300 200 

### 1.o 

# ------



# ------

0.5 8 

### 300 200 

### 1.o 6-9 100 0.5 c 

### 100 

### <1.O <I

### -0

6-9 <I00



### 0.5 D 

## <I00

<

### 1.0

<

### 1

## .o 6-9 

## <I00

0.0 E 

# -

I

### DRAFT Level 

### B pretreatment involves equalization of low volume wastes, neutralization to a pH 6-9 and skirnmipg of surface .oil. Metal cleaning wastes are stored in a large tank or small pond and fed slowly to the neutralization tank for small volume wastes and boiler blowdown. There 

### is no sludge removal on pretreatment of cooling tower blowdown. Level C 

### pretreatment is the same as Level 

### B except that the metal cleaning wastes are neutralized, clarified and discharged. Provision ismade for sludge removal. L.eve1 

### D pretreatment is essentially that for BPCTCA 

### for direct discharge to surfacewater. For 

### this level all waste st-reamswith exception of the cooling tower blowdown are fed into a tank for pH adjustment (optimum in the 9-11 pH range), oil 

### is skimmed from the liquid surface, and suspended solids are removed in

### a clarifier. Acid isthen added to reduce pH to 6-9 prior 

### todischarge. Cooling tower blowdown istreated separatelywith sulfiteto remove free chlorine. Costs and estimated effluent concentrations achieved for oil and gas-fired plants are given in Table VIII-1 and VIII-2. Detailed model description for bevel 

### D 

### is given inthe following subsection. Costs for Levels 

### A, B, and C 

### are roughly estimated from cost experience with similarwastewater volumes and compositions inother industries as well as from steam electric power plants. Capital cost data for wastewater pretreatment facilities for oil and gas-fired steam electric power plants discharging to public sewerage systems are summarized in Table VIII-3. Table VIII-3. SUMMARY OF 

### CAPITAL COSTS OIL AND 

### GAS

### FIRED PLANTS 25 MW 

### PLANT $ 

### Per KW IGC Pretreatment Technology Level Category Low Volume Wastes 0.38 1.20 1.20 1.60 Metal Cleaning Wastes 0.02 0.80 1.20 1.O 

### Cooling Tower 

### Blowdown NT 

### NT NT 1.66 Boiler Blowdown NT 

### NT NT 0.54 

### TOTAL COST

### DRAFT Table VIII-3. (CONT'd)

Category 500 

### MW Plant $ Per 

### KW 

### IGC Pretreatment Technology Level

Low Volume Wastes 0.15 0.50 0.50 

### 0.79 Metal Cleaning Wastes 0.01 0.10 0.10 0.20 Cooling Tower Blowdown NT 

### NT 

### NT 0.31 Boi1 erBlowdown 

### NT 

### NT NT 0.10 

### TOTAL COST 0.16 0.6 0.6 1.40 Note: NA not applicable todischarge to 

### POTW 

### NT Not treated



### A 

# - Flow equalization. 

### B

# - Equalization and neutralization of low volume wastes to pH 6-9, skimming of surface oil. Metal cleaning wastes combined with low volumewastes and neutralized without s1udge removal. C

# - Same as Level B 

### except metal cleaning wastes neutralized, clarified and discharged. Provision ismade for sludge removal. 

### D 

# - Equalization, pH adjustment, oil skimming, reacidification, clarification. Cooling tower blowdown treated 

### with sulfite. Coal-Fired Plants Coal-fired plants have ash pond discharges, airpollution control wastewater, coal pile runoff, ion-exchange regenerants, miscellaneous low volume wastes, cooling tower blowdown and metal cleaning wastes. Estimated wastewater volumes inliters/day (GPD) forthe plants sizes given are: '



### Low Volume Wastes 

# - Air Pollution Wastes 3800 (1000) 151,400 (40,000) 

# - Ion Exchange Regenerants 11400 (3000) 454,000 (1 20,000) 

# - Mi

### scellaneous 3800 (1000) 15,400 (40,000) a 

### Metal Cleaning Wastes 380 ( 

### 100) 10,200 ( 

### 2,700)
-

### DRAFT

o 

### Cooling Tower 94,600(25000) 1,892,000(500,000) Blowdown Area Runoff 3,800( 1000) 94,600( 25,000)

o 

### Ash Pond Discharge 3,800( 1000) 75,700( 20,000)

The low volume wastes contain primarily acids bases and suspended solids. The metal cleaning wastes contain acids, bases, metals, and suspended solids. Cooling tower blowdown as discussed for oil and gas-fired plants may contain a variety of additives but 

### for purposes of 

### this cost development is assumed to contain only free chlorine. Area runoff contains acid, suspended solids and possibly some metals. Ash pond discharges contain suspended and dissolved solids. The 

### minimum level for pretreatments, defined as Level 

### A, consists of that level of technology which is equalled or exceeded by most or all of the existing plants. This level involves some flow equalization and neutralization resulting from the combination of waste streams of differing pH. There isno control or treatment of runoff. Expenditures, both capital and operating are small. Level 

### B pretreatment involves equalization of low volume waste streams, neutralization to pH of 6-9. Metal cleaning wastes are stored in a large tank or small pond and fed slowly to the treatment system for low volume wastes. There is no control of area runoff. Level C 

### pretreatment is the same as Level 

### B except that the metal cleaning wastes are neutralized, clarified and discharged. Provision is made for the sludge removal. Level 

### D pretreatment involves technology that will in general meet the requirements of BPCTCA for direct discharge to surfacewater. For this level area runoff from coal piles and ash transport water overflow are retained in a pond and fed continuously to a central pretreatment system. Metal cleaning wastes are similarly retained and fed continuously to the system. The pretreatment system itself isdescribed in a following subsection. Itconsists primarily of a tank for pH control and oil skimming and a clarifier for suspended solids removal.DRAFT 

### Costs and effluent quantities for the four treatment levels for coal-fired plants are summarized in Tables VIII-4 and VIII-5. Costs for Level D 

### are developed in a following subsection. Capital cost data for wastewater pretreatment faci1 ities for coal-fired steam electric power plants discharging to pub1

### ic sewerage systems are summarized in

### Table VIII-6.

Model Pretreatment Plants

# - Level D 

### Technology 

# --- - 

### Model pretreatment plant costs have been developed for power plants of 25 MW 

### and 500 MW 

### capacity of combined pretreatment facilities for low volume and metal cleaning wastes. Separate cost estimates are presented for treatment of area runoff and ash transport water discharge. Estimates are fornational average costs and do not consider regional differences in construction costs. All estimates are based on the following technology: pretreatment for pH 

### adjustment to between 6.0 and 9.0, flow equalization so that the instantaneous peak discharge does not exceed five times the monthly average flow rate, reduction of suspended solids to POTW 

### limitations, and removal of biocides, oil and grease and metals to levels specified in the effluent limitation guide1ines regulations. Estimated operating costs are presented for centralized pretreatment facilities for each model plant size. Operating costs include labor, fuel and power, chemicals, maintenance, residue removal and management. Actual operating costs may vary widely for those shown herein because of variations in processes, degree of automation, and allocation of joint labor costs. The model waste treatment plants which form the basis of the cost estimates are designed to provide Level D 

### treatment for low volume wastes and metal cleaning wastes from coalfired plants. Ash transport water or ash pond overflows are not included in the cost basis. Combination of cooling water system blowdown with 

### low volume and metal cleaning wastes isnot desirable, since cooling tower blowdown is a continuous operation requiring minimal treatment. Low volume and metal cleaning wastes are intermittentlyproduced and require flow equalization and more intensive treatment. Plants discharging cooling water system blowdown to the public sewer will have to add the cost of required pretreatment of cooling system blowdown to the cost of the pretreatment of the low volume and metal cleaning wastes.

### DRAFT TABLE 

### 1111-4

WASTEWATER TREATMENT COSTSAND RESULTING WASTE-LOAD CHARACTERISTICS FOR TYPICALPLANT

PLANT SIZE 

### 7.5 MW PLANT AGE

# -- " YEARS PLANT LOCATION '---"---"

COSTS OF TREATMENT TO ATTAINSPECIFIED LEVELS

COST CATEOORY

, TOTALINVLSTED CAPITAL I ANNUAL CAPITAL RECOVERY ANNUAL OPERATINOAND MAINTENANCE COSTS (EXCLUDINQENERQY AND POWER) ANNUAL EMEROYAND POWER COSTS

RtSULTUI@WASTE-LOAD CHARACTERISTICS - TOTALANNUAL CCSTS 

# 1 3,250 COSTS(O) toATTAINLEVEL



### 27,200

# 1 33,100

# 1 46,800



### (a)Low volume andmetal cleaningwastes combined (b)

### Cooli

### ng Tower Blowdown 

### NOTE: TSS, Fe, and Cu, raw wastes concentrations estimated from TableA-V-20 ofDevelopment Document 

### EPA 440/1-74029 a (12) 

### Level A

# - Flow Equalization 

### Level B

# - Equalizationof low volume wastes, followedby neutralization 

### topH 6-9, skimming of surfaceoil. Metal cleaningwastes cmbined with

### low volumewastes and 

### n~ut rali

### zedwithout 

### s1

### uAqeremoval

# . Level 

### C

# - Same asLevel 

### B exceptmetal cleaningwastes neutralized, clarified with sludgeremoval and discharged. Level 

### D

# - Equalization, pH adjustment, oil skimming, clarification, reacidification. Cooling tower bl

### owdown treatedwith sulfi

### te. COSTS 

### Mi 

### 7s/KWH* 

# 10.017 

### 0.145

# 1 0.176 

# 1 0.249 

## j I 

### *Plant operating atfull capacityand 7500 hrs/yr.

PARAMETER 

### (a)TSS Fe 

### Cu 

### pH Oil & 

### Grease 

# -- (b)

### Free C12 D 

### 143,000

23,300 20,000 500 C 

### 90,000 14,600 18,000 500 A 

### 20,000 3,250 Small Small

CONCENTRATION (mg/l) (wm) E B 

### 75,000 12,200 15,000

Small

RAWWNTREATED) 

### 300 150 0.7


# ----

--

# --

# -

0.5 AFTER TREATMENT TO LEVEL A 

### 300 150 0.7



## ------
------ 0.5 E

A 9 

### 300 150 0.7 6-9 4

### 100

0.5 c D

<

### 100 

### <.1.O



### 0.7 6-9

<

### 100

0.5 <

### 100 <lo 

### 0.7 6-9 <I00

0.0DRAFT 

### VIII-5

WASTEWATER TREATMENT COSTSAND RESULTING WASTE-LOAD CHARACTERISTICS FOR TYPICALPLANT

SUBCATEGORY 

### Coal FiredPlant
PLANTSIZE 

### 500 MW 

# ----- ---------- PLANT AGE , YEARS PLANTLOCATION

COSTS OF TREATMENT TO ATTAIN SPECIFIED LEVELS

- - - 

### *Plant

### operatingatfull capacity

### and 7500hrslyr. RLSUMIWIWASTE-LOAD CHARACTERISTICS COST CATEOORI

TOTAL INVLSTEDCAPITAL
AUNUAL CAPITAL RECOVERY ANNUAL OPERATINO AND YAINTENANCE COSTS (EXCLUDINO ENEROYAND POWER) ANNUAL EYIRIY AND COWER COSTS TOTALANNUAL COSTS I



# I I CoNc~NTnAT~o~ (ma/l) (mn)



### (a) 

### Low

### volumeand

### metal 

### cleaningwastes combined (b) 

### CoolingTowerBlowdown 

## NOTE: TSSy Fe,

### and

### Cu,

## rawwastes concentrations

### estimated from

### TableA-V-20 of

### Development

### Document

## EPA 440/1-74029

### a 

### (12) 

## Level

## A

# - FlowEqualization 

## Level B

# - Equalizationof 

## lowvolume

### wastes, followed

### by neutralization to

### pH 6-9,

### skimming of 

### surface oil. 

### Metal cleaning

### wastes combined 

### with lowvolumewastes and neutral

### ized 

### without sludgeremoval. 

## Level C

# - SameasLevel 6 

### exceptmetal 

### cleaning

### wastes neutralized,clarified 

### with sludge

### removal anddischarged. 

## Level

## D

# - Equalization,

### pH adjustment,oi

### 1 skimming,clarification,

### reacidification. Cooling 

### towerbl

### owdown treated

### with sulfi te. cosrs(t) roATTAIN LEVEL 

# - A

~~~Y~~~



### 16,300



### Sma1

### 1 Small 16,300

COSTS 

### Mi1s/KWH* 

# I 0.004 

# 1 0.035

# 1 0.041 0.078

# 1 B 

### 350,000

57,000 70,000

2,000 129,000 C 

### 350,000

57,000 93,100

2,500 1 

### 152,600' 0

7903000 

### 128,500 163,800 3,000 295,300 E

### DRAFT TableVIII-6. SUMMARYOFCAPITALCOSTSCOAL FIREDPLANTS

Category LowVolume Wastes Metal Cleaning Wastes Cooli

### ng TowerBlowdown Area Runoff Ash Handling Wastes Boi

### 1erBlowdown 25

### MW Plant $ 

### PerKW IGC Pretreatment TechnologyLevel

TOTAL COST



### Category LowVolumeWastes Metal Cleaning Wastes Cooli

### ng TowerBlowdown Area Runoffs Ash Pond Discharges Boi

### 1erBlowdown TOTALCOST 500

## MW Plant

NOTE: NA 

### - Not app 

### 11

icabletodischarge to POTI 

### NT 

### - Not treated LEVELSOF PRETREATMENT
A 

### - FlowEqualization B

### - Equalizationand neutralizationof low volumewastes to pH 6-9

### skimmingof surfaceoil. Metal cleaning wastes combined with lowvolumewastesand neutralizedwithout sludge removal. C

# - SameasLevel B 

### exceptmetal cleaningwastes neutralized, clarifiedanddischarged. Provision ismade forsludge removal

# . D

# - Equalization,pH adjustment,oil skimming, clarification, reacidification. Cooling towerblowdown treatedwith sulfite.

### DRAFT 

### Power plants sizes selected formodel treatment plants are 25 MW 

### and 500 MW. 

### The 25 MW 

### istypical of the smaller plants discharging to POTWs and listed in

### the ERCO 

### survey sample (18). Eighty-seven and one half percent of all plants listed and discharging to POTWs have less than 100MW 

### IGC, with 37.5 percent having less than 25 IGC. Seventy-six percent of the generating capacity discharging to POTWs is in the size range between 250 and 1000MW, and the 500 MW 

### plant is considered representative of this large size group. For the 25 MW 

### model plant itwas assumed that pretreatment would be a batch operation with low volume and metal cleaning wastes combined. Treatment would consist of gravity separation (skimming) of oils, followed by lime precipitation of metals, sedimentation, withdrawal of sludge, adjustment of pH 

### to a neutral range, and controlled discharge. Figure VIII-1 is

### a flow diagram for a small batch plant. For the 500 MW 

### itwas assumed that pretreatment would be on a semicontinuous basis. Metal cleaning wastes would be stored in an equalization tank and bled into the treatment operation at a controlled rate. The treatment process would consist of oil and grease skimming in the equalization tank, lime addition in the reactor, sedimentation and clarification, and final adjustment of pH 

### before discharge tothe public sewer. Sludge from the clarifier would be dewatered on vacuum filters, with the filtrate returned to the treatment plant influent. Figure VIII-2 isa flow diagram of this process. These model treatment plants provide a level of treatment consistent with effluent guide1ines for direct discharge. 

### For metal cleaning wastes, the removals of metals are limited to the minimum solubilities discussed in Section VII. Blowdown from the cooling water system is a significant waste stream not included in the 

### combined pretreatment plants. Level D 

### pretreatment for discharge to the POTW 

### consists of dechlorination and pH adjustment. A 

### flow diagram for accomplishing this pretreatment is shown on Figure VIII-3. Cost Variances 

### Age Age affects the cost of pretreatment in terms of cost per unit of power produced primarily because age affects efficiency and p1ants with lower effficiency wi11 produce more wastes per unit of power produced. Plants with lower efficiencywill also have lower utilization and therefore produce fewer units of power in relation to their installed capacity.

### LOW VOLUME WASTES 200 gpd/MW



### METAL CLEANING WASTES 4 gpd/MW

BOILER BLOWDOWN 

### 40 gpd/MW 

### LIME 

### ACID

FIGURE

### VIII-1. Model Waste Pretreatment Plant25 MW Generating Faci

### 1ity For Level D Pretreatment

### DRAFT

CLEANING WASTES (5.4 gpd/MW) BOILER TUBE BOILER FIRESIDE AIR PREHEATER OIL & GREASE 5.4 gpd/MW EQUALIZATION TANK 

# - rawVOLUMEWASTES (320 gpdh~)
WATER TREATMENT? LIME AIR POLLUTION CONTROL-. FLOOR DRAINS- 'LABORATORY'&SAMPLING. 

## -

ACID

CLARIFIER

I'

SLUDGE FILTER 

# 6

4r SEWER TO POTW



### FIGURE VIII-2. Model Waste Pretreatment Plant 500 

### MW Generating Facility for Level 

### D Pretreatment VIII-18

### DRAFT 

### Size Size is related to age in that the older plants are more likely to be smaller than the newer plants. This relation is shown in detail in the Development Document (14). Size affects the cost of pretreatment as shown by the two plant sizes, 25 

### MW 

### and 500 MW. 

### Location Location affects costs of pretreatment because of differences in construction costs and labor rates in 

### various parts of the U.S. 

### and because the choice of the treatment technology and the cost of providing that technology are related tothe availability of land. For plants discharging to public sewers, itmay be 

### assumed that they are located in urbanized areas, where land availability is somewhat limited. The extent of that limitation will vary widely depending on the size of 

### the urban area, the location of the plant in that area, and the location of the area within the U.S. Cost estimates are presented for two cases, (1)where tankage can be constructed at ground level, and (2) 

### where tankage must be supported on a steel framework over existing facilities because no other land is available. COST 

### ESTIMATES Low Volume and Metal Cleaning Wastes Low volume wastes include all wastewaters other than those forwhich specific effluent limitations have been established. Waste sources include wet airpollution control systems, water treatment systems, laboratory and sampling streams, f1 oor drainage, cooling 

### tower basin cleaning

### , and blowdown from service water systems. For the purpose of cost estimating, metal cleaning wastes have been combined with low volume wastes as the most cost effective method of handling these two waste sources. Pretreatment cost allottment to each type of waste has been estimated and is given in Table VIII-7.

### DRAFT 

### Level - 

### of Treatment Level D 

### treatment consists of retention, skimming, pH 

### adjustment for precipitation and readjustment before discharge and removal of sludges. Level D treatment meets the requirements of BPCTCA 

### for direct discharge. Capita1 Costs The following table presents estimates for capital costs of pretreatment plants for Level D 

### treatment of low volume and metal cleaning wastes, where sufficient land is available to construct all facilities at ground level.

TABLE 

### VIII-7 

### ESTIMATED CAPITAL COSTS CHEMICAL WASTES PRETREATMENT PLANT 

## Zg capacity

..

### .. Description 

# - 25 

### MW 500MW


### ~qualization ~ank Reactor Clarifier Vacuum Filter Pumps Piping Subtotal,major equipment Installation & 

### foundations Instrumentation Subtotal, construction costs Engineering & 

### contingencies Total, landnot limited $97,000 $612,000 Premiumfor limited land construction 28,000 180,000 Cost,per KW 

### IGC $ 

### 3.78 $ 

### 1.12 

### Limited land premium 1.12 0.36 Estimated Cost Allottment, Unlimited and Low Volume Wastes 2.58 0.92 Metal Cleaning Wastes 1.20 0.20

### DRAFT If land availability is limited, treatment plant components may have to be stacked vertically and tankage supported on steel framework. This would double the cost of the installation of the equipment. It would increase the total capital cost of the pretreatment plant for the 25 MW generating facility, to $5.00 per KW KGC. For the 500MW facility,the respective costs would be $792,000 and $1.58 per KW IGC. Operating Costs Operating costs include labor; fuel,power and other utilities; supplies (principally chemicals); maintenance; removal and disposal of residues; and management. Assumed unit costs for basic parameters of operating costs are shown in the following table. Table VIII-8. ASSUMED UNIT COSTS Labor, per hour, including fringe benefits Electricity, per kwh No. 2 Fuel oi

### 1,per MM Btu Chemicals Lime,per ton Sulfuric Acid, per ton

The following table shows operating costs for the combined pretreatment of low volume and metal cleaning wastes in treatment plants of the type described in this report. Annual costs are calculated on the basis that the generating facility is operated as a base load plant operating 8000 

### hours per yearwith each boiler cleaned once per year.DRAFT



### TABLE VIII-9 OPERATING COSTS-PRETREATMENT OF 

### LOW VOLUFE 

### AND METAL CLEANING WASTES

Operating Labor 

### (1 ) 

### Maintenance (2) 

### Utilities 

### Water (3 

### ElectricPower (4 Sewer Charge 

### (5) Chemicals and Supplies (6

Total Ann'ual production, 

### KWH 

### Unit cost, milsper 

### KWH At .90 capacity factor InstalledGenerating Capacity 

### 25 MW(7) 500 MW(8)

-- -- 

### Notes to Table VIII-9



### (1)25 MW 

### Plant

# - 4 hrs/wk 200 hrs/yr 500 MW 

### Plant

# - 40 hrs/wk 2000 hrs/yr (2) 

### 3%

### of capital

### cost (3) Citywater @ 

### .6O/lOO 

### gall (4) 25

### MW Plant

# - 5 

### kwh 

### x 200 hrs 500

### MW Plant

# - 30 kwh 

### x 2000 hrs 

### (5) Sewer 

### service charge @ .30/1000 

### gal (6) Lime 500 mg/l SulfuricAcid 100mg/l (7) Design flow: Low volume wastes: 5,000 gpd 

### (from DD) 

### Metal cleaningwastes: 

### 25,000 

### gallonsbatch (8) Design flow: Low volume wastes 200,000 gpd 

### (from

### DD) Metal cleaningwastes: 

### 500,000

### gal

### lons batch

### DRAFT Ash Transport Water Ash transport water isthewater used inthe hydraulic transport of bottom or flyash. Since the water serves only as a carrier ofthe ash, water quality isnot a significant consideration. As a matter offact, a high level of suspended solids isdesirable since itfacilitates the subsequent settling out and removal ofthe ash. Settling basins are a normal component of ash transport systems. They may be either ofthe mechanical clarifier or natural lagoon (ash pond) type. Wet ash isremoved from the clarifiers and disposed offsite. The supernatent water is recycled tothe process. The only routine blowdown from the system isthe water removed with the wet ash. Waste streams result from overflows during periods of precipitationand for intermittant blowdown purposes. 

### Atone of the plants visited, blowdown from a recirculating water system used totransport flyash from oil fueled boilerswas discharged tothe POTW. This waste can be combined with area runoff and could be treated together. Costs for pretreatment of discharges from ash transport systems are estimated from the volume ofthe portion coming tothe retention pond. Metal Cleaning Wastes Metal cleaning wastes includewastes from the cleaning of the inside (waterside) of the boiler tubes, usually done by chemical means, and the outside (fireside) of the boiler and air preheater surfaces, usually done by mechanical means. Cleaning isdone about once per year for each generating unitduring a periodwhen the unit isnot ingenerating service. The wastes are discharged during a few hours over a two-day period and contain high concentrations of suspended solids, chemicals used inthe cleaning process, and metal and other residues removed from the surfaces being cleaned.

### DRAFT 

### Level 

## of Treatment Level D 

### treatment consists of retention, skimming, pH 

### adjustment to specific levels 

### toprecipitate various metals, removal of sludges, and readjustment of pH 

### fordischarge. Costs The combined model treatment plants for low volume wastes have been sized to handle metal cleaning wastes as well. Costs for pretreatment of metal cleaning wastes are therefore included in

### the cost of pretreatment for low volumes. Boi7er Blowdown The quality of boiler blowdown isgenerally higher than the quality of

### the raw water source, which formost plants discharging to POTWs is the municipal water supply. If boiler blowdown is discharged to the waste stream, it

### will tend to dilute the wastes and make any treatment less efficient. Boiler blowdown should therefore be returned 

### tothe plant servicewater system, and 

### In most plants this isdone. Therefore, no costs have been developed for pretreatment of this waste source. Cooling System Wastes Cooling system wastes are discharges of water that have been used 

### tocool the 

### main condenser surfaces. Cooling systems are either of the once-through or recirculating type. There are 

### no known plants which discharge once-through cooling water to a POTW. 

### Recirculating systems require blowdown which becomes 

### a waste source. Levels 

### - of Treatment Levels A 

### thru C 

### treatment for cooling system blowdown consists of discharge tothe POTW 

### without 

### pretreatment, If the only biocide 

### or other cooling water treatment chemical used ischlorine and the POTW 

### does 

### not impose restrictions on chlorine in discharges to the sewer, cooling water blowdown may 

### be discharged without pretreatment. In that

### DRAFT



### case the only costs will consist of the sewer service charges. Level D 

### treatment forresidual chlorine consists of dechlorination and possible pH adjustment and meets the requirements of effluent limitation guidelines for BPT 

### for direct discharge. Level D 

### treatment for cooling water system blowdown is shown in

### Figure VIII-3. Capital Costs Table VIII-10 presents estimates for capital costs of pretreatment for cooling water system blowdown. These costs assume that chlorine is used as a biocide, that the POTW 

### requires removal of residual chlorine, and that no other biocides or inhibitors unacceptable to the POTW are added to the,cooling water system. Opesrating Costs Operating costs for pretreatment of cooling system blowdown pretreatment consists of operating labor, maintenance, and chemicals for dechlorination. They are summarized in Table VIII-11. Area Runoff The area runoff subcategory includes runoff from material storage. Coal is stored in open piles and oil is stored in

### covered tanks. Materials storage therefore represents a significant source of waste only for coal-fired plants. And 

### since the burning of oil produces only about two percent of the amount of ash produced by the burning of coal, ash ponds are a feature of coal burning plants primarily. Material storagewastes from coal piles and ash ponds are therefore applicable to coal burning plants only. No plants discharging area runoff toPOTWs 

### were found in the industry survey.DRAFT

TURBINE

COOLING 

# iL1 1

TOWER



### - 

# - MAKE-UP I



### BLOWDOWN 

### (I000 gpd/MW 

# -

L CONDENSER



### I IME 

# t 

# - - I MONITOR 

# I I 

# - RESIDUAL 

# I

.CHLiiINE 

# -

FIGURE VIII-3. CoolingWater System Blowdown Treatment For Level D Pretreatment

### DRAFT

Tab1e 

### ,VIII-10 ESTIMATED CAPITAL COST 

### COOLING WATER SYSTEM BLOWDOWN TREATMENT



### Installed Generating Capacity nescription 

### 25 MW 

### 500 MW 

### ContactTank 

### Chemical Feed System Piping Subtotal, major equipment Installation & 

### foundations Instrumentation Subtotal, construction costs Engineering O 

### contingencies

Total Cost Cost 

### per 

### KW IGC

Tab1e

### VIII-11 ESTIMATED 

### OPERATIKG COSTS 

### COOLING WATER SYSTEM BLOWDOWN TREATMENT


### Installed Generating Capacity Description 

# - 25 MW 

### 500 MW 

### Operating Labor Maintenance Chemicals Total 

### Unit costs, mils/KWH 

### at .90 capacity factorDRAFT

Level Dtreatment for coal pilerunoff and ash pond overflows consists of neutralization and sedimentation. Itscost isa function of the size of the catchment area covered by the coal pileand the ash pond and the design meteorological conditions atthe particular site. The regulation (40 CFR 423.40) require that treatment facilities be sized to treat the runoff from a 10-year, 24-hour rainfall event to produce an effluent having suspended solids of less than 50 mg/l and a pH between 6.0 and 9.0. The applicable technology consists of linedponds capable of holding various volumes of runoff. Capital Costs For 

### a 500 

### MW plant, a coal pile representing 90 days storage 

### will occupy 10 

### - 40 acres. A tetention basin designed toprovide one hour detention atthe maximum 10 minute rate associated with a 10-year, 24 hour storm 

### will generally meet the effluent requirement. Depending on location, such a retention basin could cost $27,000, $96,000, exclusive of land, or $0.05-$0.19 per KW IGC. OperatigCosts Operating costs for pretreatment facilities for runoff from coal piles and ash ponds are limitedto chemicals for neutralizing. It isestimated that chemicals for this purpose would cost $360 per year for a 25 MW plant and $7,200 per year for a 500 

### MW plant. This corresponds to a unit cost of .0018 mils per KWH generated for a 90 percent capacity factor. The following table (VIII-12) presents estimates for capital costs of pretreatment plants for Level C treatment of low volume and metal cleaning wastes for a coal-fired plant where sufficient land isnot available. ULTIMATE DISPOSAL Costs 

### -- For Land Destined Solid Wastes Waste treatment processes discussed inthis report are separation techniques which produce a liquidfraction suitable for discharge to the public sewer or reuse within the plant and a liquid or solid residue which requires ultimate disposal. Many of the processes produce sludges containing between 0.5 and 5.0 percent solids. These sludges are generally further dewatered atthe siteto 15 to 30 percent solids and then disposed off site. The following paragraphs discuss techniques and costs of dewatering and ultimate disposal applicable to steam electric power plants.

### DRAFT Table VIII-12.ESTIMATED CAPITAL COSTS 

### CHEMICAL 

## WASTES 

## PRETREATMENT PLANTLEVEL C

Installed 

### Generating 

### Capacity 

### Description 25

### MW 500

### MW EqualizationTank 

### Reactor Clarifier 

### Pumps pi

### ping 2,000 

### Subtotal.

### ma.ioreaui~ment$ 

### 33.000 

### Installation-& 

### ~ohdations ' 

### 17

### ;OOO 

### Instrumentation 4,000 

### Subtotal,

### construction costs $ 

### 54,000 

### Enginnering & 

### Contingenci

### es 16,000 

## Total,land

### not limited $ 

### 70,000 $ 

### 270,000 

### Premium for 

### limited land

construction 20,000 80,000



### Costper 

### KW IGC Limited

### Land Premium



### Estimated costallottment,unlimited 

### land 

### Lowvolumewastes 2.40 

### Metal cleaning

### wastes 1.20DRAFT

User Charges For Sewer Service Ofthe twenty-two plants visited inthis study only 15 percent reported separate charges for sewer service, while 35 percent reported surcharges on their water bills for sewer service. Fifty percent did not report charge for sewer service as they were municipal utilitieswhose internal billingsystems did not allow for tracking of such charges. The average charge for sewer service inthis industry is $0.06/1000 L ($0.23/1000 gal

### ). Evaporation Ponds Evaporation ponds are used by the industry as a method of ultimate disposal, particularly inthe arid areas of the southwestern United States. The extensive land requirements make it unsuited for use inurban areas where plants discharging to POTWs are generally located. Conveyance 

### Off Site The cost of this method of disposal isentirely related to the distance between plant and disposal site. Alternate methods of conveyance are trucks, railroads and pipelines. Trucking ismost economical for distances under 50 miles. Costs are ofthe order of ($.01-$0.13 per 1000 liter) ($0.05-$0.50 per 1,000 gallon) miles exclusive of final disposal charges. Landfills Landfills are the most common method of disposal of solidwastes. Costs ofdisposal at landfills range from $1 to$9 per metric ton ($2-10 per ton). Recent federal regulations require landfills to provide leachate control, so that soluble components of the wastes cannot cause groundwater pollution.

### DRAFT 

### ENERGY 

### CONSIDERATIONS In contrast to the effluent guidelines for thermal discharges, the promulgation of standards for pretreatment isnot expected to involve significant energy requirements or tohave a measurable impact on the energy production of the power plant. None of the treatment technologies described herein affect the power generating cycle and therefore do not require "retrofitting"to the extent that the performance of the plant is impaired. None of the processes involve a change of state and the only requirements for energy are for possible pumping needs. Even these needs are sitedependent and many power plants may find itfeasible to install the equipment in such a manner that repumping isnot required. For estimating purposes ithas been assumed that a pretreatment plant handling low volume and metal cleaning wastes from a 25 MW 

### generating plant would have a connected load of 5HP and that a similar plant for the 500 MW 

### generating facilitywould have a connected load of 30 HP. Each plant would operate the equivalent of 800 hours per year, at full connected load. Under these conditions, the energy consumption by the waste treatment facilities would constitute about 0.02 percent of the generating capacity of the 25 MW 

### generating plant and less than 0.01 percent of the generating capacity of the 500 MW 

### plant.

### DRAFT

SECTION IX



### PRETREAMENT STANDARDS



### "To be Propo,sed 

### by the Environmental Protection Agency"DRAFT SECTION 

### X

ACKNOWLEDGMENTS

The preparation of this reportwas accomplished through the efforts ofthe staff of the Environmental Engineering Department, HittmanAssociates, Inc., Columbia, Maryland under the overall direction of 

### Mr. Burton C. Becker, Vice President, Operations. 

### Mr. Dwight B. Emerson and Mr. J. Carl Uhrmacher shared direction of the day-to-day work on the program. Mr. John Lum, Project Officer, Effluent Guidelines Division, through his assistance, leadership, and advice has made an invaluable contribution to the preparation of this report. Mr. Lum provided a careful review of the draft report and suggested organizational, technical and editorial changes. He also was most helpful inmaking arrangements for the drafting, presenting, and distribution of this report. Mr. Ernest P. Hall, Jr., Assistant Director, Effluent Guidelines Divisionand Mr. Harold B. Coughlin, Branch Chief, Effluent Guidelines Division, Mr. Devereaux Barnes, and Mr. Elwood Forsht, Project Officers, Effluent Guidelines Division offered many helpful suggestions during the program. Appreciation isextended to the Federal Power Commission, Washington D.C., and to 

### Mr. Vacys Saulis, Region V Office of the Environmental ProtectionAgency, Chicago, Illinois, to acknowledgment James Ferry-EPAIOffice of Planning and Evaluation Garry F. Otakie-EPAIOffice ofWater programs, Theordore Landry-EPA Region I,Fred Roberts EPA Corvallis, Oregon Environmental Research Laboratory, Harvey Lunenfeld-EPA Region 11, Gary Liberson-EPA Office ofAnalysis and Evaluation for assistance and cooperation rendered to us inthis program. Additionally, we wish to thank Mr. John Rose of Daniel P. Frankfurt, PC, for his invaluable aid. Also our appreciation isextended to the staff of the Environmental Engineering Department of Hittman Associates, Inc. for their assistance during this program. Specifically, our thanks to: Dr. Leon C. Parker, Senior Chemical Engineer Dr. T. Goldshmid, Environmental Engineer 

### Mr. J. Carl Uhrmacher, Senior Chemical Engineer Mr. Roger S. Wetzel, Environmental Engineer

### DRAFT



### Ms. Mr. Mr. Mr. Mr. Mr. Mr. Mr. Mr. Barbara A. 

### White, Manuscript Coordinator Craig S. 

### Koralek, Environmental Engineer Kenneth G. 

### Budden, Environmental Engineer Robert G. 

### Matysek, Junior Chemical Engineer Carroll E. 

### Stewart, Chemical Engineer Robert T. 

### Brennan, Environmental Engineer Efim M. 

### Livshits, Environmental Engineer Anthony T. 

### Shemonski, Environmental Engineer Werner H. 

### Zieger, Environmental Engineer

### DRAFT 

### SECTION XI REFERENCES Barker, P.A., 

### "Water Treatment for Steam Generating Systems", Industrial Water Engineering, MarchIApril 1975. City Council of Roswell, New Mexico, Ordinance No. 933, Industrial Waste Ordinance 

### -- of The City - 

### of Roswell, New Mexico. Dean, John G., 

### Bosqui, Frank 

### L., and Lanouette, Kenneth H., 

### "Removing Heavy Metals from Wastewater," Environmental Science and Technology, Volume 6, No. 6, June 1972. Duffey, J.G.,Gale, S.B., and Bruckenstein S., "Electrochemical Removal of Chromates and Other Metals," Cooling Towers, Volume 2, pp. 44-50, 1975. Goldstein, Paul, "Control of Chemical Discharges for the Steam Electric Power Industry1;NUS Corporation, Pitssburg, PA., 

### Presented atConference on Water Quality

# - Considerations for Steam Electric Power Plants, Atomic Industrial Forum, Inc., Phoenix, AZ, January 1975. Nall, Douglas E., 

### "The Influence of EPA 

### Guidelines on Treatment of Power Plant Wastes," Industrial Water Engineering. Office of Science and Technology, Electric Power and the Environment, August 1970. 

### -- Patterson, J.W., etal, Wastewater Treatment Technology, Illinois Institute for Environmental Qua1 ity, Chicago, Illinois, August, 1971. Scott, David L., 

### Pollution in the Power Industry, D.C. 

### Heath and Co., Lexington,MA, 1973. Stratton, Charles L., 

### and Lee, G. 

### Fred, "Cooling Towers and Water Quality,"Journal of the Water Pollution Control Federation, Volume 47, 

### No. 7, July 1975. Teknekron, Inc., Water Pollution Control 

## of 

# the Steam Electric Power Industry

# - Assessment of the Costs and Capabilities of Water Pollution Control Technology -- 

### for the SteamElectric Power Industry, Volume 1, Berkley, CAY

### December 1975.DRAFT Teknekron, Inc., Water Pollution Control -- of the Steam Electric Power Industry

# - Economic Impact Water Pollution Control inthe Steam Electric 

### -- Power Industry, Volume 2, Berkeley, CA, December, 1975. Teknekron, Inc., Water Pollution Control -- for the Steam Electric Power Industry

# - Appendix, Volume 

### 3, Berkeley, CA, December 1975. U.S. Environmental ProtectionAgency, Development Document for Proposed Effluent Limitations Guidelines and New Source Performance Standards for the Steam 

### -- -- Electric Power Generating Industry, October, 1974. U.S. Environmental Protection Agency, Office of Water Program Operations, pretreatment of Pollution Introduced into PublicallyOwned ~reatrnent Works October 1973. U.S. Environmental Protection Agency, Office of Water Program Operations, State and Local Pretreatment Programs (Draft Federal Guidelines) Volume 1, August, 1975. U.S. Federal Power Commission, Statistics

# of Publicly Owned Electric Utilities inthe United States 1970, Washington, D.C., FebEaT1972. 

### U.S. Environmental Protection Agency, Office of Planning and Evaluation, Environmental Assessment ofAlternativeThermal Control Strategies for the 

### - -- Electric Power Industry, December 1974. Fair, G.M., Geyer, 

### C.G., and Okun, D.A., Water and Wastewater Engineering, New York, NY, 1968.DRAFT SECTION XI1

GLOSSARY

Absolute Pressure. The total force per unit area measured above absolute vacuum as a reference. Standard atmospheric pressure is 101,326 N/l12 (14.696 psi) above absolute vacuum (zero pressure absoluter. Absolute Temperature. The temperature measured from a zero atwhich all molecular activity ceases. The volume of an ideal gas isdirectly proportional to itsabsolute temperature. It ismeasured inOK (OR) corresponding to 

### "C 

### + 273 (OF 

### + 459). Anion. The charged particle ina solution of an electrolyte which carries negative charge. Anthracite. 

### A hard natural coal of high lusterwhich contains littlevolatile matter. Approach Temperature. The difference between the exit temperature ofwater from a cooling tower, and the wet bulb temperature of the air. Ash. The solid residue following combustion of a fuel. Ash Sluice. The transport of solid residue ash by water flow ina conduit. Backwash. Operation of a granular fixed bed inreverse flow towash out sediment and reclassify the granular rnedia. 

### Bag Filters. A fabric type filter inwhich dust laden gas ismade to pass through woven fabric to remove the particulatematter. Base. A compund which dissolves inwater toyield hydroxyl ions (OH-). Base-Load Unit. An electric generating facility operating 

### --- continously at a constant output with littlehourly or daily fluctuation.DRAFT

Biocide. An agent used tocontrol biological growth. Bituminous. 

### A coal of intermediate hardness containing between 50 and 

### 92 percent carbon. Blowdown. 

### A portionofwater ina closed system which iswasted inorder to prevent a built-up of dissolved solids. Boiler. 

### A device inwhich a liquid isconverted into its vapor state 

### by the action of heat. Inthe steam electric generating industry, the equipment which converts water into steam. Boiler Feedwater. The water supplied to a boiler to be converted into steam. Boiler Fireside. The surface of boiler heat exchange elements exposed tothe hot combustion products. Boiler Scale. An incrustationof salts deposited on the waterside of a boiler as a result ofthe evaporation of water. BoilerTubes. Tubes contained ina boiler through which water passes during its conversion intosteam. BottomAsh. The solid residue leftfrom the combustion of

### a fuel, which falls to the bottom of the combustion chamber. Brackish Water. Water having a dissolved solids content between that of fresh water and that of sea water, generally from 1000 to 10,000 mg per liter. Brine. Water saturatedwith a salt. Bus Bar. A conductor forming a common junction between two 

### -- or more electric circuits. A term commonly used inthe electric uti1i ty industry refer toelectric power leaving a station boundary. Bus bar costs would refer to the cost per unit of electrical energy leaving the station.

### DRAFT 

### Capacity Factor. The ratio of energy actually produced to that which would have been produced in the same period had the unit been operated continously rated capacity. Cation. The charged particles in solution of an electrolyte which are positively charged. Carbonate Hardness. Hardness of water caused by the presence of carbonates and bicarbonates of calcium and magnesium. Circulating Water Pumps. Pumps which deliver cooling water to the condensers of a power plant. Circulating Water System. A 

### system which conveys cooling water from its source to the main condensers and then to the point of discharge. SYnonymous with cooling water system. Clarification. A 

### process for the removal of suspended matter from a water solution. Clarifier. A 

### basin in which water flows at a low velocity to allow settling suspended matter. Closed Circulating Water System. A 

### system which passes water through the condensers, then through an articial cooling device, and keeps recycling it. - 

### Coal Pile Drainage. Runoff from the coal pile as a result -- 

### of rainfall. Condensate Polisher. An 

### ion exchanger used to adsorb minute quantities of cations and anions 

### resent in condensate as a result of corrosion and erosion of metallic surfaces. Condenser. A 

### device for converting a vapor into its liquid phase. Construction. Any placement, assembly, or installation of facilities or equipment (including contractural obligations to purchase such facilities or equipment) atthe premises where the equipment will be used, including preparation work at the premises.DRAFT Convection. The heat transfer mechanism arising from the motion of a fluid. Cooling Canal. 

### A canal inwhich warm water enters at one end, iscooled by contact with air, and isdischarged at teother end. Cooling Lake. See Cooling Pond. Cooling Pond. 

### A body ofwater inwhich warm water iscooled by contact with air, and iseither discharged or returned for reuse. Cooling Tower. 

### A configured heat exchange devicewhich transfers reject heat from circulating water tothe atmosphere. Cooling Tower Basin. 

### A basin located atthe bottom of a cooling tower for collecting the fallingwater. Cooling Water System. See Circulating Water System. Corrosion Ihibitor. 

### A chemical agent which slows down or prohibits a corrosion reaction. Counterflow. 

### A process inwhich two media flow through a system inopposite directions. Critical Point. The temperature and pressure conditions at which the saturated-liquid and saturated-vapor states of a fluidare identical. For water-steam these conditions are 3208.2 psia and 705.47"F. Cycling Plant. 

### A generating facilitywhich operates between peak load and base load conditions. Inthis report, a facility operating between 2000 and 6000 hours per year. Cyclone Furnace. A water-cooled horizontal cylinder in which fuel isfired, heat is released at extremely high rates, and combustion iscompleted. The hot gases are then ejected intothe main furnace. The fuel and combustion airenter tangentially, imparting awhirling motion to the burning fuel, hence the name Cyclone Furnace. Molten slag forms on the cyclinderwalls, and flows off for removal.DRAFT

Deaeration. A process by which dissolved airand oxygen are stripped from water either by physical or chemical methods. Deaerator. A device for the removal of oxygen, carbon dioxide and other gases from water. Degasification. The removal of a gas from a liquid. Deionizer. A process for treating water by removal of cations and anions. Demineralizer. See Deionizer. Demister. A device for trapping liquidentrainment from gas or vapor streams. Dewater. To remove a portion of the water from a sludge or a slurry. Dew Point. The temperature of a gas-vapor mixture at which the vapor condenses when it iscooled at constant humidity. Diesel. An internal combustion engine inwhich the temperature atthe end of the compression issuch that combustion isinitiatedwithout external ignition. Discharge. To release or vent. Discharge Pipe or Conduit. A section of pipe or conduit from the condenser discharge to the point ofdischarge intoreceivingwaters or cooling device. Drift. Entrained water carried from a cooling device by the exhaust air. 

### Dry Bottom-Furnace. Refers toa furnace inwhich the ash iscollected as a dry solid inhoppers atthe bottom of the furnace, and removed from the furnace inthis state. 

### Dry Tower. A cooling tower inwhich the fluidto be cooled Tlows within a closed system. This type of tower usually uses finned or extended surfaces. 

### Dry Well. A dry compartment of a pump structure ator be1ow pumping level

### , where pumps are 1 ocated.

### DRAFT


### Economizer. A 

### heat exchanger which uses the heat of combustion gases to raise the boiler feedwater temperature before the feedwater enters the boiler. Electrostatic Precipitator. A 

### device for removing particles from a stream of qas based on the principle that these particles carry eiectrostatic charges and can therefore be attracted toan electrode by imposing a potential across the stream of gas. Evaporation. The process by which a liquid becomes a vapor. Evaporator. A 

### devicewhich converts a liquid into a vapor by the addition of heat. Feedwater Heater. Heat exchangers in which boiler feedwater ispreheated by steam extracted from the turbine. Filter

## Bed. A device for removing suspened solids from water, consisting of granular material placed in horizontal layers and capable of being cleaned hydraulically by reversing the direction of the flow. Filtration. The process of passing a liquid through a filtering medium forthe removal of suspned or colloidal matter. Fireside Cleaning. Cleaning of the outside surface of boiler tubes and combustion chamber refractories to remove deposits formed during the combustion. Flue Gas. The gaseous products resulting from the 

### -- combustion process after passage through the boiler. 

### Fly Ash. 

### A 

### portion of the non-combustible residue from a furwhich iscarried out of the boiler by the flue gas. Fossil Fuel. A 

### natural solid,liquid or gaseous fuel such as coal, petroleum or natural gas. Generation. The conversion of chemical ormechanical energy into electrical energy. Heat Rate. The fuel heat input (in

### Joules or BTU) 

### -- required to generate a KWH.DRAFT Heating Value. The heat available from the combustion of a given quantity offuel as determined by a standard calorimetric process. Humidity. Pounds ofwater vapor carried by 1 1b of dry air. Ion. A charged atom, molecule or radical, the migration ofwhich affects the transport of electricity through an electrolyte. Ion Exchange. 

### A chemical process involving reversible interchange of ions between a liquidand a solid but no radical change inthe structure ofthe solid. Lignite. 

### A carbonaceous fuel ranked between peat and coal. Makeup Water Pumps. Pumps which providewater to replace that lost by evaporation, seepage, and blowdown. Mechanical DraftTower. 

### A cooling tower inwhich the air flow throuqh the tower ismaintained b.y fans. Inforced drafttowers the air isforced throughVthetower by fans located at itsbase, whereas ininduced draft towers the air is pulledthrough the tower by fans mounted on top of the tower. Mill. One thousandth of a dollar. Mine-mouth Plant. 

### A steam electric powerplant located within a short distance of a coal mine and towhich the coal istransported from the mine by a conveyor system, slorry pipe1ineor truck. Mole. The molecular weight of substance expressed ingrams (orpounds). Name Plate. See Nominal Capacity. Natural Draft Cooling Tower. A cooling tower through which air iscirculated by natural or chimney effect. A hyperbolic tower isa natural draft tower that is hyperbolic inshape. Neutralization. Reaction of acid or alkaline solutions with the opposite reagent until the concentrations ofhydrogen and hydroxyl ions are about equal.DRAFT

New Source. Any source, the construction ofwhich is commenced after the publicated of proposed Section 306 regulations. Nominal Capacity. Name plate

### - design rating of a plant, or specific piece of equipment. Nuclear Energy. The energy derived from the fission of nuclei of heavy elements such as uranium or thorium or from the fusion of the nuclei of lightelements such as deuterium or tritium. Once-through Circulating Water System. 

### A circulating water system which draws water from a natural source, passes itthrough the main condensers and returns itto a natural body ofwater. Overflow. 

### (1) Excess water over the normal operating limits disposed of by letting itflow out through a device provided for that purpose; (2) The device itselfthat allows excess water toflow out. Osmosis. The process of diffusion of a solvent thru a semi-permeable membrane from a solution of lower to one of higher concentration. Osmotic Pressure. The equilibrium pressure differential across a semi-permeable membrane which separates a solution of lower from one or higher concentration. Oxidation. The addition ofoxygen to a chemical compund, generally, any reactionwhich involves the loss of electrons from an atom. Packing (Cooling Towers). A media providing 

### large surface area for the purpose of enhancing mass transfer, usually between a gas or vapor, and a liquid. Precipitation. A pheonomenon that occurs when a substance held insolution ina liquid phase passes out of solution into a solid phase. Preheater (Air). A unit used toheat the air needed for combustion by absorbing heat from the products of combustion.DRAFT

Peak-load Plant. 

### A generating facility operated only 

### -- during periods ofmaximum demand, inthis report is isa facility operating less than 2000 hours per year. Penalty. 

### A sum to be forfeited, or a loss due to some action. Plant Code Number. 

### A four-digit number assigned toall powerplants inthe industry inventory for the purpose ofthis study. Plume (Gas). 

### A conspicuous trail of gas or vapor emitted from a cooling tower or chimney. Powerplant. Equipment that produces electrical energy, generally by conversion from heat energy produced by chemical or nuclear reaction. Psychrometric. Refers to air-water vapor mixtures and their properties. 

### A psychrometric charg graphically displays the relationship between these properties. Pulverized Coal. Coal that has been ground to a powder, usually of a sizewhere 80 percent passes through a #ZOO U.S.S. sieve. Pump Runout. The tendency of a centrifugal pump to deliver more than itsdesign flow when the system resistance falls below the design head. Pyrites. Combinations of iron and sulfur found incoal as FeS2. - Radwaste. Radioactivewaste streams from nuclear powerplants. Range. Difference between entrance and exit temperature ofwater ina cooling tower. Rankine Cycle. THe thermodynamic cycle which isthe basis of the steam-electric generating process. Rank of Coal. 

### A classification of coal based upon the 

### --- fixed carbon on a dryweight basis and the heat value. Recirculation System. Facilitieswhich are specifically designed todivert the major portion of the cooling water discharge back tothe coolingwater intake.DRAFT Recirculation. Return of cooling water discharge back to the coolingwater intake. Regeneration. Displacement from ion exchange resins ofthe ions removed from the process solution. Reheater. 

### A heat exchange device for adding superheat to steam which has been partially expanded inthe turbine. Relative Humidity. Ratio of the partial pressure of the water vapor tothe vapor pressure ofwater atair temperature. Reinjection. To return a flow or portion of flow, into a process. Reverse Osmosis. The process of diffusionofa solvent thru a semi-perable membrane from a solution of higher to one or lower concentration, affected by raisingthe pressure of a more concentrated solution to above the osmotic pressure. Reduction. 

### A chemical reactionwhich involes the addition of electrons toan iontodecrease itspositive valence. Saline Water. Water containing salts. Sampling Stations. Locations where several flow samples are tapped for analysis. Sanitary Wastewater. Wastewater discharged from sanitary conveniences ofdwellings and industrial facilities. Saturated 

### - Air. Air inwhich the water vapor is in equilibriumwith the liquidwater at air temperature. Saturated Steam. Steam atthe temperature and pressure at which the liquid and vapor phase can exist inequilibrium. Scale. Generally insoluble deposits on heat transfer surfaces which inhibit the passage of heat through these surfaces. Scrubber. A device for removing particles and/or objectionable gases from 

### a stream of gas. Secondary Treatment. The treatment of sanitary wastes water by biological means after primary treatment by sedimentation.DRAFT

Sedimentation. The process of subsidence and deposition of suspended matter carried by a liquid. Sequestering Agents. Chemical compunds which are added towater systems to prevent the formation of scale by holding the insoluble compunds insuspension. Service Water Pumps. Pumps providingwater for auxiliary plant heat exchangers and other uses. Slag Tap Furnace. Furnace inwhich temperature ishigh enough tomaintain ash (slag) ina molten state until it leaves the furnace through a-tapatthe bottom. The slag falls intothe sluicingwater whwere itcools, disintegrates, and iscarried away. Slimicide. An agent used to destroy or control slimes. Sludge. Accumulated solids separated from a liquid during processing. Softener. Any device used to remove hardness from water. Hardness inwater isdue mainly to calcium and magnesium salts. Natural zeolites, ion exchange resins, and precipitation processes are used to remove the calcium and magnesium. Spinning Reserve. The power generating reserve connected tothe

### bus bar and ready totake load. Normally consists of units operating at less than full load. Gas turbines, even though not running, are considered spinning reserve due totheir quick start up time. Spray Module (Powered Spray Module). 

### A water cooling device consisting of a pump and spary nozzle or nozzles mounted on floats and moored inthe body ofwater to be cooled. Heat istransfered principally by evaporation from the water drops as they fall through the air. Station. A plant comprising one or several units for the generation of power. Steam Drum. Vessel inwhich the saturated steam is separated from the steam-water mixture and intowhich the feedwater is introduced.DRAFT
Supercritical. Refers to boilers designed tooperate at or above the critical point ofwater 22,100 knIm2 and - 374.0°C (3206.2 psia and 705.4"F). Superheated Steam. Steam which has been heated to a temperature above that corresponding tosaturation at a specific pressure. Thermal Efficiency. The efficiency ofthe thermodynamic cycle producing work from heat. The rationof usable energy to heat input expressed as percent. Thickening. Process of increasing the solids content of sludge. Total Dynamic 

### -- Heat (TDH). Total energy provided by a pump consisting ofthe difference inelevation between the suction and dischage levels, plus losses due to unrecovered velocity heads and friction. Turbidity. Presence of suspended matter such as organic or inorganic material plantkton orother microscopic organisms which reduce the c l a r i t y o f the water. Turbine. A device used toconvert the energy of steam or gas into rotationmechanical energy and used as prime mover todrive electric generation. Unit. Insteam electric generation, the basic system for power generation consiting ofa boiler and itsassociated turbine and generator with the required auxiliary equipment. 

## Utilitx. Public utility. A company, either investorowned or publicly owned which provides service tothe public ingeneral. The electric utilitiesgenerate and distribute electric power. Volatile Combustion Matter. The relatively light components ina fuel which readily vaporize ata relatively low temperature and which when combined or reacted with oxygen, give out lightand heat. Wet Bottom Furnace. See slag-tap furnace. Wet Bulb Temperature. The steady-state, nonequilibrium 

### -- temperature reached by a small mass ofwater immersed under adiabatic conditions ina continous stream ofair.DRAFT

Wet Scrubber. 

### A device for the collection of particulate matter from a gas stream and/or absorption of noxious gases from the stream. Zeolite. Complex sodium aluminum silicate materials, which have ionexchange properties and were the original ion exchange materials before synthetic resins were processed.DRAFT APPENDIX A

STATISTICAL ANALYSIS OF HISTORICAL DATA

Effluent pretreatment standards achievable by steam electric power plants discharging theirwastewater effluents into publicly-owned treatment facilitieswere determined from statistical analysis of historical data describing the pollutants concentration over extended periods of time. Of the three plants analyzed only one provides partial pretreatment which includes flow equalization, oi1 removal, and settling. The remaining two plants discharge untreated waste. This appendix describes the statistical approach used and presents results of that analysis. The statistical analysis was based on the assumption that the data are normally distributed, that is, their frequency of occurrence isfully defined by two statistical parameters: The mean X and the standard deviation s. Each set of data representing the variation of concentration of a particular pollutant intreated effluent-wasstatistically examined to determine the mode of normal distribution that best describes itsfrequency of occurrence. Both arithmetic and logarithmic modes of normal distributionwere considered. The degree of fit ofthe data to any particular mode was determined by calculating the coefficients of skewness and of kurtosis. The former measures the symmetry of the distribution diagram and the lattermeasures the height of the peak of the diagram relative tothat of a normal curve. 

### A perfect fit to normal distribution is indicated by a zero coefficient of skewness and a coefficient of kurtosis ofthree. Ifneither the arithmetic nor the logarithmic modes of normal distribution describe the frequency of occurrence of a data set, a modified logarithmic mode was employed to "force" the data into normal distribution. This mode is referredto as the three-parameters logarithmic type of normal distribution. It isassumed that deviation from normal distribution occurs inthe tails of the frequency curve where the probability of occurrence isvery low. Thus, it isassumed that deviation of data from the perfect logarithmic mode of normal distribution isdue to small sample size. The overall effect of this deviation isto increase the variance of the data set. The three-parameters approach is designed to remove this deviation inthe tails by adding or subtracting a constant number, smaller than the first element of the data set, toeach member of the sample. The exact value ofthe constant isdetermined byDRAFT iterating a series ofmathematical expressions designed togenerate a zero coefficient of skewness and a value of approximately three for the coefficient of kurtosis. The mathematical treatment of data was carried out by a computer program. Each set ofdata was initially read by the computer which sorted elements inascending order. The computer then calculated the first four moments and the coefficients of skewness and kurtosis for each of the three modes of normal distribution. The statistical coefficients of the three-parameters logarithmic mode of normal distributionwere determined by initially assigning an arbitrary constant to be added toeach element ofthe data set. The computer calculated the coefficient of skewness and determined from itsvalue whether the diviation from normal distribution occurred at the lower or upper tail ofthe diagram. 

### A deviation inthe lower tail was indicated by a negative value and the computer proceeded tocorrect itby adding toeach of the elements half ofthe arbitary constant. 

### A positive coefficient of skewness was corrected by subtracting half of the constant. This was repeated until a zero coefficient of skewness was obtained. The computer then calculated the percent cumulative of each element inthe series and converted it to standard deviation expressed as probit (standard deviation plus five). Based on the values of the coefficients of skewness and kurtosis the mode of normal distribution that best described the distributionof the data set was selected and the data were subjected to a least squares analysis as a function of the corresponding probits to determine the coefficients of regression (slope, intercept, and coefficient of determination). The regression linewas used to determine the 

### 99 percent confidence upper limits. Table 1 liststhe mathematical expressions used to calculate the various statistical parameters. These are shown in Tables 

### 2 to 

### 6 for various pollutants discharged from three pants. Each of these tables shows the calculated values of the firstfour moments, and the coefficients of skewness and kurtosis, for each of the modes of normal distribution. Also shown inthese tables are the constants used to normalize the distribution of the data, the coefficients of regression (slope, intercept, and coefficient 

### of determination), and the 99 percent confidence limits. Plots of the best fit data and their regression lines are shown inFigures 1 to 19. The statistical parameters ofthe best fit data are summarized inTable 

### 7. The historical data analyzed are listed in Table 

### 8.

### DRAFT Table A-1. 

### MATHEMATICAL EXPRESSIONS FOR DETERMINATION 

### OF STATISTICAL PARAMETERS

n Firstmoment 

### rn =- 

### I 

# C xi (mean) 1 

### n 

### i =l

Secondmoment m=- 

### X: 

# -

# x2(variance) 2 

### n i=l

Thirdmoment

n n n Fourthmoment m4= 

# xx:? n

# " x;+"* n 

# z -

# 3x4 i =l i=1 

### i =l

Coefficient ofskewness 

### Y =

# % m2



### Coefficientofkurtosis 

### & = 

### m4 2 m2



### Probi t

### DRAFT

Slope

Intercept

Coefficientofdetermination



### Xi 

# - thevalue of element 

### i of a data set. Xi=X' forarithmeticmode, Xi=log

### Xifor logarithmicmode, andXj=log

## !xi + a) forthreeparameters mode of normal distribution, where 

### a istheadded or subtracted constant.



### n 

# - number of elements ina data set 

### Co

# - 2.515517 dl 

# - 1.432788 C1

# - 0.802853 d2

# - 0.189269 

### C2

# - 0.010328 dg

# - 0.001308 

### E(Q)< 4.5 x 

### 10+

### TableA-2: STATISTICALANALYSIS OF HISTORICAL DATA (MG'/L)

PlantNo. 7308 Wastewater Source: RetentionPond

Pollutant 

# I Iron 

# I Nickel 

# I Si1 ver

Mode ofNormal

Distribution Statistical

Parameter 

# I I Arithmetic

ThirdMoinent 

# I 0.28 

# 1 0.00 

# 1 

# --- 1 0.035") Mean Variance Logarithmic Logarithmic Three Parameters Logarithmic

4.75 0.68 Arithmetic Arfthnletic

, I I I I I I CorrectionConstant 

## 1 I I 

## 1 I -0.92 

## I 

## I Logarithmic

4.86 0.005

FourthMoment Coeff. ofSkewness Coeff. ofKurtosis 2.40 51214.64'

I I I I I I I 1.73 0.09(1)

I

Slope I I I I I I

(1) calculatedwithdatax 100 

# --- 1.45

# '

3.18( 0.77 0.49 1.63

Intercept Coeff. ofDetermination 99%ConfidenceLimit 0.00 0.4 1.51

1.88 1.15(') 

# 1 1.58(1) 

# 1

-4.67
1 1

0.91 6.67 0.002(l) -1.15(')

2.33(') I 1



# I 0.97(') 3.1 6.64(1) -1.15 (1

### 1 (1) 2.33 0.026(1) 1.21(1
2.87(1

-4.17(') 

# 1 -3.52(1) 

# I

I 0.33 (') 0.07 0.78(:) 0.00~~) 2.16(')

### TableA-3. STATISTlCALANALYSIS 

### OF HISTORICAL DATA (MG/L)

PlantNo. 7308 Wastewater Source: Cooling Tower Basin 1 I Iron 

# I Copper 

# 1 Chromium Pollutant

Arithmetic - -

Logarl

thmic ThreeParametersLogarithmic KodeofNormal

Parameter ThreeParameterstogarithmic Arlthmetic Logari

thmic Arithmetic Logarl

thmic

Mean Variance ThirdMoment FourthMoment Coeff. of Skewness Coeff. ofKurtosis CorrectionConstant Slope Intercept Coeff. ofDetermination 99%Confidence Limit

(I)calculatedwithdatax 100

### TableA-3. STATISTICAL ANALYSIS OF HISTORICAL DATA (MG/L) (CONTI..NUED)

Lead

Parameter

Variance 543.1

FsurthNoment 

## 1 712419.5 

## 1 I I Coeff. of Skewness 

# 1 0.'87

# 1 I Coeff. of Kurtosis 2.41 

# '1 correction constant 

### ( 

# I Slope Intercept

1 I Corff. of DeterminationI 99%ConfidenceLimit 

# I 1LogaI thmic 

# I Zinc

ThreeParameters Loga- Arith- Logarithmic ThreeParameters Loga- Arithrithiilic metic ThreeParameters Loga- Logarithrnic rithmic

(1) pH units (2) catculatedwith data x 100 (3) calculatedwith data x.10

### TableA-4. STATISTICALANALYSIS OF HISTORICAL DATA (MG/L)

PlantNo. 8696 Wastewater Source: Demineralizer

Pollutant 

# t Suspended Solids 

# , BOD COD 

## I I ThreeParametersLogari

thmic ThreeParameters ArtthModeofNormal

Ofstrlbutlon Statistica ArithParameter metlc ThreeParametersArithLoga- rithmic Arlthmetic Logart

thmlc

FourthMoment 319.44 Coeff. ofSkewness 0.50 Coeff. of Kurtosis 1.60 CorrectionConstant Slooe Intercept

LCoeff. ofDetermination

99IConfidence Lfmtt

(1) @i units

### Table A-5. STATISTICAL ANALYSIS OF HISTORICAL DATA (MGIL)

t Plant No. 8696 Wastewater Source: Cooling tower blowdown

Pollutant SuspendedSolIds COD

ThreeParameters Statistical Arith- Loga- Arith- Loga- Loga- ArithParameter metic rithmic metic ri thmic rithmic metic

Mean 7.46 0.87 14.25 13.48 13.59 2.54 Variance 0.08 0.0003 18.35 0.017 0.013 0.84 

### I ThirdMoment 

## I 0.01 

### I 0.00 

### 1 48.30 

### 1 -0.00018 

### 1 0.00 

### 1 -0.04 

## I FourthMoment 

### 1 0.007 

### 1 0.00 

### 1 926.85 

### 1 0.00079 

### 1 0.0005 

### 1 1.2 

## 1 Coeff. of Skewness 

## 1 0.6 

## 1 0.47 

## 1 0.61 

## 1 -0.083 

## 1 0.00 

## 1 -0.05

-- -- Coeff. of Kurtosis 1.13 9.42 2.75 2.72 2.65 1.683 CorrectionConstant 

# I 1.54 

### I slope 

### 1 0.33 

### 1 I I 1 0.13 

### 1

-- Intercept 5.83 0.50 Coeff. ofDetermination 0.92 0.96 99%Confidence Limit 8.11 15.39 h ri thmic ThreeParametersLogari

thmi

(1) pH units

### TableA-6. STATISTICAL ANALYSIS OF HISTORICAL DATA (MG/L)

Plant No. 8392 Wastewater Source: Cooltng tower Botler

Pollutant

Distribution Statistical

Parameter

Mean Variance ThirdMoment FourthMoment Coeff. ofSkewness Coeff. ofKurtosis CorrectionConstant Slope Intercept Coeff. ofOetermination 99%Confidence Limlt Chromate 

# m I Three Parameters Arithnetic Logarlthmtc Logarithnlc Phosphate 

# P

Three Parameters Artthmetfc Logarithmic Logarithmic

17.1 16.59 16.51 13.98 0.009 0.002

### TableA-7. STATISTICAL PARAMETERS SUMMARY FOR BEST FIT DATA (MG/L) 

# I Coolfng Tower Blowdown 

# I Demineralizer Source (Plant 8696) (Plant 8696) 

# 1' 

# I I 99% Statistical Concentration Confidence Statfstlcal Concentratlon Parameter Mode 

# I
Limit 

# I
Mode 

# 1
Mean Limit 

# I

PH Suspended Solids

Source 

# I Logarlthmfc 3-Parameter CoolingTower Blowdown (Plant 8392) b Arithmetfc 3-Parameter

Boiler (Plant 8392) 2.36 26.40

CoolingTower Basin (Plant 7308) 7.46 13.59 3.85 27.55

Parameter Chromate Phosphate I 8.11 15.39

Source 3-parameter 3-parameter Arithmetic

I

Parameter Fe Cu

-- - Retention Pond 4.26 9.26 8.55 97.56 2.53

Statlstical Mode Arfthmetlc 3-parameter 6.89 3-parameter 

# 1 22.27

16.51 3-parameter

Parameter Fe Ni 28.20

17.78 16.24 14.53

Concentration Mean

5.27 0.58



# I Ag Arithmetic 3-parameter

.

99% Confidence

Limit 12.83

0.80

Arithmetfc 3-parameter

-- -p .O.04 0.03
I 4.75 1.3 6.67 3.1DRAFT

Table A-8. HISTORICAL DATA 

### LMG/L)
---

Plant No. 8696 Cooling Tower Blowdown

COO 24.0, 29.0, 27.0, 12.0, 33.0, 30.0, 30.0, 31.0, 2.2, 24.0, 23.0, 21.0, 20.0 Dernineralizer Backwash

COD 22.0, 19.0, 21,0, 7.0, 13.0, 22.0, 22.0, 24.0.. 39.0, 39.0, 13.0, 71.0, 57.0, 18.0, 20.0, 83.0,

Plant No. 8392 Cooling TFwx chromate 16,0, 24.0, 18.0, 14.0, 16.0, 14.0, 14.0, '4.'- 14.0* 12.0, 10.0, 14.0, 14.0. 16.0, 14.0, 14.0. 16.0, 16.0* 14.0 Boiler Phosphate 15.0, 18.0, 16.0, 26.0, 19.0, 15.0, 18.0, 13.0, 20.0, 17.0, 14.0, 12.0, 10.0, 20.0, 13.0, 21.0, 19.0, 18.0
Plant No. 7308 Retention Pond Fe 4.0, 179.0, 4.0, 6.0, 5.0

Cooling Tower Basin Fe 11.4, 7.25, 5.75, 1.0, 7.5, 3.5, 4.5, 1.3 C

u 0.05, 1.35, 0.12, 0.1, 0.1

### DRAFT

3.0 4.0 5.0 6.0 7.0 

### PROBITS FIGURE.A-1. Normal Distribution Diagram for Supsended Solids Concentration inWastewaters from Demineralizer (Plant 8696)

### 5.0 6.0 

### PROBITS

F1GURE.A-2. Normal Distribution Diagram 

### for Phosphates Concentration 

### In Boiler Blowdown (Plant 8696)

### 3.0 4.0 5.0 6.0 7.0 

### PROBITS

FIGURE 

### A-3. Normal Distribution Diagram for pH Concentration 

### In Wastewater from Deminealizer (Plant 

### 8696)

### DRAFT

3.0 4.0 5.0 6.0- 

### PROBITS

FIGURE 

### A-4.Normal Distribution Diagram for COD 

### Concentration In

### Wastewater From Dernineralizer(P1ant 8696)

### 5.0 

### PROBITS

FIGURE 

### A--5. 

### Normal Distribution Diagram for Supsended Solids Concentration 

### In Cooling Tower Blowdown (Plant 8696)

### 5.0 6.0 PROBITS



### FIGURE A-6. 

### Normal Distribution Diagram for COD Concentration In Coolinq Tower Blowdown 

### (Plant 86961

### PROBITS GURE 

### A-7. Normal Distribution Diagram for Chrornates Concentration Cooiing Tower Blowdown (Plant 

### 8395) 

# -

### 5.0 6.0 7.0 PROBITS 

### FIGURE A-8. Normal Distribution Diagram for BOD5 Concentration InCooling Tower Blowdown (Plant 8696)

### PROBITS 

### FIGURE A-9.. 

### Norma? Distribution Diagram 

### for pH Concentration In Cooling Tower Blowdown (Plant 8696)

### DRAFT

3.0 4.0 ' 5.0 6.0 7.0 

### PROBITS

FIGURE A-1 

### il.,Normal Distribution Diagram for BOD5 Concentration in Demineralizer Backwash (Plant 8696)

### DRAFT

4.O 5.0 6.7 7.0 

### PROBITS FIGURE A-11.. Normal Distribution Diagram for Normalized Nickel Concentration inRetention Pond (Plant No. 7308)

### DRAFT

4.0 5.0 6.0 

### PROBITS 

### FIGURE .A-1

### 2.Normal Distribution Diagram for Normalized ,Chrom'ium Concentration inCoolingTower Basin (Plant No. 

### 7308)

### DRAFT

4.0 5.0 6.0 7.0 

### PROBITS FIGURE-A-1

### 3. Normal Distribution Diagram for Normalized Lead Concentration inCooling Tower Basin (Plant No. 7308)

### DRAFT


# I 

# I

4.O 5.0 6.Q 

### PROBITS 

### FIGURE A-14. 

### Normal Distribution Diagram forNormalized Z1.n~ Concentration In Cooling Tower Basin (PlantNo. 7308)

### DRAFT

4.O 5.O 6.O 

### PROBITS

FIGURE 

### A-15. Normal Distribution Diagram for Iron Concentration inRetenti~n Pond 

### (Plant No. 

### 7308)

### PROBITS

FIGURE 

### A-16. N'ormal Distribution Diagram for IronConcentration InCooling Tower Basin (Plant No. 7308)

### 5.0 

### 6.0 

### PROBITS FIGURE 

### A-17. Normal Distribution Diagram for Normalized pH 

### Concentration In Cooling Tower Basin (PlantNo. 7308)

### DRAFT

4.0 5.0 6.0 

### PROBITS



### FIGURE A-18. Normal Distribution Diagram for Silver Concentration Retention Pond (PlantNo. 7308)

### DRAFT



### PROBITS FIGURE 

### A-19. Normal Distribution ~ia~ram for Normalized copper 

### Concentration Cooling Tower Basin (PlantNo.7308)

### DRAFT

APPENDIX 

### B WATER GLOSSARY

### DRAFT WATER GLOSSARY

Acid-washed activated carbon

# - Carbon which has been contactedwith an acid solution with the purpose of dissolving ash inthe activated carbon. Acidity

# - The quantitative capacity of aqueous solutions to react with hydroxyl ions. It 

### ismeasured by titrationwith a standard solution of a base to a specified end point. Usually expressed as miligrams per literof calcium carbonate. Acre-foot 

### - (1) 

### A term used inmeasuring the volume of water that isequal to the quantity.of water required tocover 1 acre 1 ft 

### deep, or43,560 cu ft. 

### (2) A term used insewage treatment inmeasuring the volume ofmaterial ina tricklingfilter. One acre-foot contains 43,560 cu ft 

### ofwater. Activated Carbon 

### - Carbon which istreated by high-temperature heatingwith steam or carbon dioxide producing an internal porous particlestructure. The internal surface area ofgranular activatedcarbon is estimated to be about 3,600 sq ft 

### gr. Activiated Sludge Treatment Process

# - (See Sludge, Activated). Adsorption 

### - The adhesion ofan extremely thin layer of molecules (of gas, liquid) tothe surfaces of solids (granular activiated carbons for instance) or liquids with which they are incontact. Adsorption isotherms (activated carbon) 

# - A measurement of adsorption determined ata constant temperature by varying the amount ofcarbon used or the concentration impurity incontact with the carbon. Advanced Waste Treatment 

# - Any treatment method or process employed following biological treatment (1

### ) to increase the removal of pollution load. (2) to remove substances that may be deleterious to receivingwaters or the environment. (3) to produce a high-quality effluent suitable for reuse inany specific manner or for discharge under critical conditions. The term tertiary treatment iscommonly used todenote advanced waste treatment methods.

### DRAFT 

### Aerated Pond 

### - A natural or artificial wastewater treatment pond in which mechanical or diffused airaeration is used to supplement the oxygen supply. Aeration 

### - The bringing about of intimate contact between airand liquid by one of the following methods spraying the liquid in the air, bubbling airthrough the liquid (diffused aeration) agitation of the liquid to promote surface absorption of air (mechanical aeration). Aerobic 

### - Living or active only in the presence of oxygen. Aerobic Biological Oxidation 

### - Any waste treatment or process utilizing aerobic organisms in the presence of airor oxygen, as the agent for reducing pollution load or oxygen demand or organic substances in waste. The term isused in reference to secondary treatment of wastes. A1 icide 

### - Chemicals used in the control of phytoplankton algae) in

### bodies of water. 

# +

Alkalinity

# - The capacityof water to neutralize acids, a property imparted by thewater's content of carbonates, bicarbonates, hydroxides, and occassionallyborates

## , silicates, and phosphates. Itis expressed in

### miligrams per literof equivalent calcium carbonate. Anaerobic 

# - Living or active only in

### the absence of free oxygen. Anaerobic Biological Treatment 

### - Any treatment method or process utilizing anaerobic or facultative organisms 

### inthe absence of airfor the purpose of reducing the organic matter in wastes or organic solids settled out of wastes commonly referred to as anaerobic digestion or sludge digestion when applied tothe treatment of sludge solids. Anaerobic Waste Treatment 

# - Waste stabilization brought about through the action of microorganisms in the absence of airor elemental oxygen. Usually refers towaste treatment by methane fermentation.

### DRAFT

Anion Exchange Process

# - The reversible exchange of negative ions between functional groups ofthe ionexchange medium and the solution inwhich the solid isimmersed. Used as a wastewater treatment process for removal of anions, e.g., carbonate. Anionic Surfactant

# - An ionic type ofsurface-active substances that has been widely used incleaning products. The hydrophilic group ofthese surfactants carries a negative charge inwashing solution. Apparent Density (Activated Carbon) 

# - The weight per unit volume ofactivated carbon. Appurtenances, Sewer

# - Structures, devices and appliances, other than pipe or conduit, which are integral parts ofa sewerage'system: such as manholes flush tanks, surface inlets. Aquifer

# - A subsurface geological structure that contains water. Assimilative Capacity

# - The capacity ofa natural body of water toreceive: (a) wastewaters without deleterious effects: (b) toxic materials, without damage to aquatic lifeor humans who consume the water; (c) BOD 

### within prescribed dissolved oxygen limits. Autooxidation

# - A chemical system which 

### will oxidize automaticallywhen some set ofconditions are met such as temperature, oxygen supply, moisture content, etc. Backflow Prevention

# - A system designed to protect potable water from wastewater contamination which could occur if

### wastewater pressure exceeds potablewater pressure over a cross-connection where one ormore check valves fail. Backsiphonage 

### - The flowing back of contaminated or polluted water from a plumbing fixture orcross connection into a water supply line,-due toa lowering of the pressure insuch line. Backwashing

# - The process ofcleaning a rapid sand or mechanical filterby reversing the flow ofwater.DRAFT Bacterial Examination

# - The examination ofwater and wastewater todetermine the Dresence. number. and identification of bacteria. Also called-bacterial anaiysis. Baffles

# - Deflector vanes, guides, grids, gratings, or similar devices constructed or placed inflowing water or sewage to (1) check or effect a more uniform distributionofvelocities; 

### (2) absorb energy; (3) divert guide, oragitate the liquids; and 

### (4) check eddy currents. Banks, Sludge 

### - Accumulations on the bed ofa waterway of deposits ofsolids ofsewage or industrial waste origin. Bed Depth (Activated Carbon)

# - The amount ofcarbon expressed inlength units which isparallel tothe flow of the stream and through which the stream must pass. Bioassay

# - (1) An assay method using a change inbiological activit.~ as a qualitativeorquantitative means 

### of analyzing a materials reponse'to industrial wastes and other wastewaters by using viable organisms or live fishas test organisms. Biochemical Oxygen Demand (BOD) 

# - (1) The quantity of oxygen used inthe biochemical oxidation oforqanic matter in a specified time, ata specified temperature, and under specified conditions 

### (2) standard test used inassessingwastewater strength. Biocides

# - Chemical agents with the capacity to kill biological lifeforms. Bactericides, insecticides, pesticides, etc. are examples. Biodegradable

# - This part oforganic matter which can be oxidized bybioprocesses, e.g., biodegradable detergents, food wastes, animal manure, etc. Biological Wastewater Treatment 

# - Forms ofwastewater treatment inwhich bacterial or biochemical action is intensifiedtostablize, oxidize, and nitrifythe unstable organic matter present. Intermittent sand filters, contact beds, trick1ing filters, and activated sludge process are examples.

### DRAFT Blowoff

# - A controlledoutlet on a pipeline, tank, 

### or conduit which isused to discharge water oraccumulations ofmaterial carried by the water. Branch

# - (1) A special form of vitrifiedsewer tileand cast ironpipe used for making connections to a sewer orwater main. They are calledT, 

### Y, T-Y, double Y, and 

### V branches according to their respective shapes. (2) Any part ofa piping system other than a main. Broad-Crested Weir 

### - Aweir having a substantial width of crest inthe direction ~arallel to the direction of flow ofwater over it. 

### This type ofweir supports the nappe for an appreciable length and produces no bottom contraction of the nappe. Also calledwidecrested weir. Buffer

# - Any of certain combinations of chemicals used to stablizethe pH values oralkalinities ofsolutions. BulkingAgent 

# - A fine solidmaterial which issometimes added toawastewater stream to promote clarification or coagulation by adding bulk to the solids. Bulking, Sludge

# - A phenomenon that occurs inactivated sludge plants whereby the sludge occupies excessive volumes and will not concentrate readily. Cake, Sludge 

### - The material resulting from airdrying or dewatering sludge (usually forkable or spadable)

# . Calibration 

### - The determination, checking, or rectifying of the graduation ofany instrument giving quantitative measurements. Carbon Column 

### A 

# - A column filledwith granular activated carbon whose primary function isthe preferential adsorption of a.particular type or types ofmolecules. Carbon TetrachlorideActivity

### - The maximum percentage increase inweight of a bed ofactivated carbon after airsaturatedwith carbon tetrachloride ispassed through it

### at a given temperature. Catalyst 

### - A substance which accelerates or retards a chemical reactionwithout undergoing any permanent changes.

### DRAFT Cation Exchange Process 

### - The reversible exchange of positive ions between functional groups ofthe ion exchange medium and the solution inwhich the solid is immersed. Used as awastewater treatment process for removal of cations, e.g. calcium. Cationic Surfactant 

# - A surfactant inwhich the hydrophilic group ispositivelycharged; usually a quaternary ammonium salt such as cetyl trimethyl ammonium bromide (CeTAB), C16H33N t 

### (CH3)3 BrCationic surfactant as a class are poor cleaners, but exhibit remarkable disinfectant properties. Cesspool 

### - An underground pitintowhich raw household sewage or other untreated liquidwaste isdischarged and from which the liquid seeps into the surrounding soil or is otherwise removed. Sometimes called leaching cesspool. Chamber Detritus

# - A detention chamber larger than a grit chamber usuallywith provision for movinq sediment without interruptingthe flow of liquid.- 

### A settling tank of short detention period designed, primarily to remove heavy settleable solids. Chamber, Flowing-Through 

# - The upper compartment ofa twostory sedimentation tank. Chamber, Grit

# - A smal'l detention chamber or an enlargement ofa sewer designed to reduce the velocity offlow of the liquid, to permit the separation ofmineral from organic solids bydifferential sedimentation. ChelatingAgents 

# - A chelating agent can attach itself to central metallic atom so as toform a heterocyclic ring. Used tomake ion-exchange more selective for specific metal ions such as nickel, copper, and cobalt. Chemical Analysis 

### - The use of a standard chemical analytical procedures todetermine the concentration of a specific pollutant ina wastewater sample. Chemical Coagulation 

### - The destabilization and initial aggregation of colloidal and finely divided suspended matter by the additionof a floc-forming chemical.

### DRAFT Chemical Oxygen Demand (COD) 

### - (1) A 

### test based on the fact that all organic compounds, with few exceptions can be oxidized tocarbon dioxide and water by the action of strong oxidizing agents under acid conditions. Organic matter isconverted to carbon dioxide and water regardless of the biological assirnilability

### ofthe substances. One ofthe chief limitations is itsa b i l i t y t o d i f - ferentiate between biologically oxidizable and biologically inert organic matter. The major advantage of this test isthe short time requiredfor evaluation (2 hr). (2) The amount of oxygen required for the chemical oxidation oforganics ina liquid. Chemical Precipitation 

### - (1) Pre~ipita~tion iduced by additionof chemicals, (2) the process of softeninqwater by the addition of lime and'soda ash as the precipitants. Chemisorption

# - Adsorption where the forces holdingthe adsorbate tothe adsorbent are chemical (valance) instead of physical (van der Waals). Chlorination 

### - The application of chlorine towater orwastewater, generally for the purpose of disinfection, but frequently foraccomplishingU other biological orchemical results. Chlorination break point

# - The application ofchlorine to water, sewage, or industrial waste containing free ammonia to the pointwhere free residual chlorine is available. Chlorination, Free Residual 

# - The application ofchlorine towater, sewage or industrial wastes to produce d i r e c t l y o rthrough the destruction of ammonia, or of certain organic nitrogenous compounds a free available chlorine residual. Chlorine, Available

# - A term used inrating chlorinated lime and hypochlorites as totheir total oxidizing power. Also a term formerly applied to residual chlorine; now obsolete. Chlorine, Combined Available Residual 

# - That portion of the total residual chlorine remaining inwater, sewage or industrial wastes atthe end of specified contact period, which 

### will react chemically and biologicallyas chloramines or organic chloramines.DRAFT Chlorine Demand 

# - The quantity of chlorine absorbed by wastewater (or water) ina given length of time. Chlorine, Total Residual 

### - Free residual plus combined residual. Chlorite, High-test Hypo 

### - A combination of lime and chlorine consisting largelyof calcium hypochloride. Chlorite, Sodium Hypo 

### - A water solution of sodium hydroxide and chlorine, inwhich sodium hypochlorite isthe essential ingredient. Cipolletti Weir

# - A contract weir of trapezoidal shape, in which the sides ofthe notch are given a slope ofone horizontal tofour vertical tocompensate as much as possible for the effect of end contractions. Clarifier

# - A sedimentation tank. Clear Well 

### - A reservoir containing water which has been previously 

### fi1 tered or purified before goining into the standpipes or distribution system. Coils, digester

# - A system of pipes for hot water or steam installed ina sludge digestion tank for the purpose of heating the sludge being treated. Collection Systems 

### - Piping and/or channel systems for gathering storm, domestic or industrial wastewaters. Can be combined or separate. Collector, Grit

### - A device placed ina grit chamber to convey deposited grittoone end ofthe chamber for removal

# . Collector, Sludge

# - A mechanical device for scraping the sludge on the bottom of a settling tank to a sump - pump, from which itcan be drawn by hydrostat,ic or mechanical action. Colloids

# - A finely divided dispersion of one material called the "dispersed phase" (solid) inanother material which iscalledthe "dispersion medium" (liquid). Normally negatively charged.

### DRAFT Color

# - A measure ofwater quality, made by eye orwith proper instrumentation. Color Bodies

# - Those complex molecules which impart color (usually undesirable) to a solution. Comminution

# - The process of cuttingand screening solids contained inwastewater flow before it

### enters the flow pumps or other units inthe treatment plant. Compatable Pollutant

# - A specific substance ina waste streamwhich alone can create a potential pollution problem, yet isused tothe advantage of a'certain treatment process when combined with other waste streams. Complexing

# - The use ofchelating or sequestering agents toform relatively loose chemical bonding as a means oftreating certain pollutant such as nickel, copper, and cobalt. Composite Wastewater Sample

# - A combination of individual samples 

### ofwater orwastewater taken atselected intervals, generally hourly for some specified period, tominimize the effect ofthe variability ofthe individual sample. Individual samples may have equal volume ormay be roughly proportioned tothe flow at time ofsampling. Concentration, Hydrogen Ion

# - The weight of hydrogen ions ingrams per literofsolution. Commonly expressed as the-p~ value that represents the logarithms 

### of the receiprocal ofthe hydrogen ion concentration. Conductance

# - A measure ofthe conducting power of a solution equal tothe reciprical ofthe resistance. The resistance isexpressed inohms. Contact Coagulation

# - A water clarification process which involves the addition ofa coagulant with appropriate mixing forthe purpose offloc formation within a 

### filtermedia, which 

### will be periodically back-flushed to permit the separation ofthe resulting solids from the main wastewater stream.DRAFT Contamination

# - A general term signifying the introduction intowater ofmicroorganisms, chemicals, wastes or sewage which renders the water unfit for its intended use. Contracted Weir 

# - A V-notch or other shaped cross-section weir for the purpose of flow measurement, as opposed to a broadwidth weir for the purpose of level control. Contraction

# - (1) The extent towhich the cross-sectional area of a jet, nappe, or stream isdecreased after

.. - passing an-orifice, weir, or notch. 

### (2) The reduction incross-sectional area ofa conduit along itslongitudinal axis. Control Section 

### - The cross-section ina waterway which is the bottleneck for a siven flow and which determines the energy head requiredto produce the flow. Corporation Cock 

### -A valve for joining a service pipe to a street water main; it isgenerally owned and operated by the water utilityor department. It cannot be operated from the surface. Countercurrent Efficiency (Activated Carbon) 

### - The unique advantage ofa carbon column that permits spent antivated carbon to adsorb impurities before the semiprocessed stream comes incontact with fresh carbon. This allows the maximum capacity ofthe activated carbon to be utilized. Crest

# - The top ofa dam, spillway, or weir, towhich water must risebefore passing over the structure. Critical Bed Depth (Activated Carbon) 

# - Ina carbon column the critical bed de~th isthe de~th of aranular carbon which ispartially spent.' It lies between the fresh carbon and the spent carbon and isthe zone where adsorption takes place. Ina single-column system this isthe amount ofcarbon that is not completely utilized. Cross Connection 

### - A water supply network and/or wastewater collection system which as been designed so as to prevent "cross-connections" which could result infunctional damage tothe system. The simpliest system is to have two separate systems, bu't this would not be justified 

### ifintersystems usage occurs only occasionally, hence back-flow preventers and other means are often used. B-llDRAFT

Cross-Sectional Bed Area (Activated Carbon) 

# - The area of activated carbon throush which the stream flow is " perpendicular. Curb Cock 

### - A shutoff valve attached tothe water service pipe from the water basin tothe building installed near the curb, which may be operated by means ofa dye key tostart or stop flow inthe water supply lines ofa building. Current Meter

# - A device for determining the velocity of moving water. Curve, Oxygen, Sag 

# - A curve that represents the profile ofdissolved oxygen connect along the course ofa stream, resulting from deoxygenation associated with biochemical oxidation oforganic matter and reoxygenation through the absorption ofatmospheric oxygen and through biological photosynthesis. Data

# - Records ofobservations and measurements of physical facts, occurrences, and conditions, reduced towritten, graphical, ortabular form. Data Correlation

# - The process of the conversion of reduced data intoa functional relationshipand the development ofthe significance of both the data and the relationships for the purpose of process evaluation. Data Reduction 

### - The process for the conversion of raw fielddata into a systematic flowwhich assists in recognizing errors, omissions and the overall data qua1

### i ty. Data Significance

# - The resultofthe statistical analysis ofa data group or bank wherein the value or significance ofthe data receives a thorough appraisal. Dechlorination Process

# - A process by which excess chlorine isremoved from water toa desired level, eq. 0.1 mg/l maximum limit. Usually accomplished by chemical reduction, by passage through carbons beds or by aeration ata suitable pH. Degreasing

# - The process of removing greases and oils from sewage, waste, and sludge.

### DRAFT Demand, Biochemical Oxygen (BOD) 

# - The quantity of oxygen utilized

### inthe biochemical oxidation oforganic matter ina specified time period and ata specified temperature. It 

### isnot related tothe oxygen requirements inchemical combustion being determined entirely by the availabilityofthe material as a biological food and the amount ofoxygen by the microorganisms during the oxidation. Desorption

# - The opposite of adsorption. 

### A phenomenon where an adsorbed molecule leaves the surface of the adsorbent. DetentionTime

# - The time allowed for solids tocollect in a settlingtank. Theoretically detention time isequal tothevolume ofthe tank divided by the flow rate. The actual detention time isdetermined by the purpose ofthe tank. Also, the design resident time ina tank or reactionvessel which allows a chemical reaction togo to completion, such as the reduction of chromium 

### +6 or the destruction ofcyanide. Dialysis

# - The separation ofa colloid from a substance in true solution by allowing the solution to diffuse through a semi-permeable membrane. Diatomaceous Earth

# - A.filtermedium used for filtration of effluents from secondary and tertiary treatments, particularlywhen 

### a very high grade ofwater for reuse incertain industrial purposes is required also used as an adsorbent for oils and oilyemulsions insome wastewater treatment designs. Differential Gauge

# - A pressure gauge used tomeasure the difference inpressure between two points ina pipe or receptacle containing a liquid. Diffuser

# - A porous plateor tube through which air is forced and divided intominute bubbles for diffusion inliquids. Commonly made of carborundum, alundurn and silicasand. Diffusion, Ridge and Furrow

### Air

# - A method of diffusing in an aeration tank of the activatedsludge process, where porous tilediffusers are placed indepressions treated by the sawtooth construction ofthe tank bottom, in rows across the tank at right angles tothe direction offlow.

### DRAFT Diffusion, Spiral Flow

### Air

# - A method ofdiffusing air ina aeration tank ofthe activated sludge process, where by means of properly designed baffles and the proper location ofdiffusers, a spiral helieal movement is given to both the airand the liquor inthe tank. Digestion

# - The biochemical decomposition of organic matter which results inthe formation ofmineral and simpler organic compounds. Disinfection

# - (1) The k i l l i n g o fthe larger portion (but not necessarily a11

### ) of harmful and objectionable microorganisms inoron a medium by means of chemicals, heat, ultraviolet light, etc. 

### (2) The use ofa chemical additive orother treatment to reduce the number of bacteria particularlythe pathogenic organisms. DissolvedOxygen (DO) 

# - The oxygen dissolved insewage, water, orother 1iquid, usually expressed inmilisrams per literor percent ofsaturation: It 

### isthe test used inBOD determination. Dissolved Solids

# - Theoretically the anhydrous residues of the dissolved constituents inwater. Actually the term isdefined by the method used indetermination. Inwater and wastewater treatment the Standard Methods tests are used. Diurnal Flow Curve

# - A curve which depicts flow distribution over the 

### 24 hour day. DrinkingWater Standards 

# - Standards defined by law and applied tothe qua1ity

### ofdrinkingwater. Educator (Activated Carbon) 

### - A 

### device with no moving parts used toforce an activated carbon water slurry through pipes tothe desired location. Effluent 

### - (1) A liquidwhich flows out ofa containing space (2) 

### sewage, water or other liquid, partially or case may be, flowing out of a reservoir basin, or the use may be flowing out of a reservoir basin, or treatment plant or part thereof.

### DRAFT


### Electrical Conductivity

# - The reciprocal of the resistance in ohms measured between opposite faces of centimeter cube of an aqueous solution ata specified temperature. Itisexpressed as microohms per centimer attemperature degrees Celsius. Elutriation 

# - A 

### process of sludge conditioning in

### which certain constituents aremoved by 

### successive flushinq with fresh water or plant effluent thereby reducing - 

### the need for using conditioning chemicals. Emergency Procedures 

### - These various special procedures necessary toprotect the environment from wastewater treatment plant failures due to power outages, chemical spills, equipment failures, major storms and floods, etc. Emulsion Breaking 

# - The method of preventing the carryover of oilsfrom one process toanother by 

### eliminating free oil by flotation,'and emulsions by the addition of aluminum or ferrous sulfate. End Contraction 

### - (1) The extent of the reduction in the width of the nappe due to a constriction caused by the ends of the weir notch. (2) 

### The walls of aweir notch which does not extend across the entirewidth of the channel of approach. Energy Head 

# - The height of

### the hydraulic grade line above the center lineof a conduit plus the velocity head of the mean velocity of the water in

### that section. Equalization Tank 

### - A capacity used to equalize wastewater flows or pollutant concentrations in effluents thus distributing itmore evenly by hours or days. Euetrophic'conditions 

# - Lake water quality degradation by enrichment of nutrients resultinq in characteristics undersirable for

### means use of

### water. Plant growth 

### in

### forms of microscopic algae and rooted aquatic weeds become prevelent in such situations. Fats (Wastes) 

# - Triglyceride esters of fatty acids. Erroneously used as synonomous with grease.

### DRAFT Faculative

# - Having the power to live under different conditions either with orwithout oxygen. Feeder, Chemical, Dry-

## A mechanical device for applying dry chemicals to water sewage at a rate controlled manually or automatically by 

### the rate of flow. Feeder Chemical Solution 

# - A mechanical device for applying chemicals in liquid towater and sewage at a rate controlled manually or automatically by the rate of flow. Filter, High-Rate 

# - A 

### trickling filter operated at a high average daily dosing rate. 

## All between 10 

### and 30 

### mgd acre, sometimes including recirculation of effluent. Filter, Intermittent

# - A 

### natural or artifical bed of sand or other fine-grainedmaterial to the surface of which sewage is intermittently added in flooding doses and through which it passes, opportunity being given for filtration and themaintenance ofaerotic conditions. Filter, Low-Rate

# - A 

### trickling filter designed to receive a small load of

## BOD Der unit volume of filterinci material and to have'a lowdosage rate per unlt-of surface area (usually 

### 1 to 

### 4mgdlacre). Also called standard rate filter. Filter, Rapid Sand 

# - A filter for the purification ofwater where waterwhich has been previously treated,usually by coagulation and sedimentation is passed downward through a filtering medium consisting of a layer of sand orprepared anthracite coal or other suitable material, usually from 24 

### to 30 

### in thick and resting on a supporting bed of gravel or a porous medium such as carborundum. The filrate is removed by an underdrain system. The filter is cleaned periodically by reversing the flowof the water upward through the filteringmedium: sometimes supplemented by mechanical or air agitition during backwashing to removemud and other impurities that are lodged in the sand.

### DRAFT Filter, Rouqhinq

# - A 

### sewage filterof relatively coarse material operated ata high rate as a preliminary treatment. Filter, Trickling

# - A 

### filterconsisting of an artifical bed of coarsematerial, such as broken stone, clinkers, slats, or

### brush over which sewage isdistributed and applied in drops, films, or spray, from troughs, drippersmoving distributors or fixed nozzles and through which ittrickles to the underdrain giving opportunity for the formation of zoogleal slimes which clarifyand oxidizethe sewage. Filter, Vacuum 

# - A 

### filterconsisting of a cylindrical drum mounted on a horizontql axis, covered with 

### a filter cloth revolving witha partial sumergence in liquid. A 

### vacuum ismaintained'under the cloth for the larger part of a revolution to extractmoisture and the cake isscraped off continously. Filtration, Biological 

# - The process of passing a liquid through a biological filter containing media on the surfaces of which zoogleal films develop which absorb and adsorb fine suspended colloridal and dissolved solids and which release various biochemical end products. float Gauge

# - A device formeasuring the elevation of the surface of a liquid, the actuating element of which isWabuoyant floatthat rests on the surface of the liquid and rises orfallswith it. The elevation of 

### the surface ismeasured by a chain or tape attached tothe float. Floc 

# - A 

### very fine, fluffymass formed by the aggre.gation 

# -of fine suspended particles. Flocculator

# - An apparatu.~ designed for the formation of f

### locTnwater 

### or sewage. Flocculation 

# - In water and wastewater treatment, the agglomeration of colloidal and finelydivided suspended matter after coagulation by gentle stirring by eithermechanical or hydraulic means. In biological wastewater treatment where coagulation isnot used, agglomeration may be accomplished biologically.

### DRAFT
Floatation

### - The risingof suspended matter tothe surface ofthe liquidina tank as scum by aeration, the evolution ofgas, chemicals, electrolysis, heat, or bacterial decomposition and the subsequent removal ofthe scum by skimming. Flowrate

# - Usually expressed as liters/minute (gallons/ minute) or liters/day (million gallons/day). Design flowrate isthat used tosizethe wastewater treatment process. Peak flowrate is

### 1.5 to2.5 times design and relates tothe hydraulic flow limit

### and is specifiedfor each plant. Flowrates can be mixed as batch and continuous where these two treatment modes are used on the same plant. Flow-Nozzle Meter

# - A water meter ofthe differential medium type inwhich the flow through the primary el ement 

### ornozzle produces a pressure difference-or differential head, which the secondary element, or float tube thenuses as an indication ofthe rateof flow. Flow-Proportioned Sample 

### - A sampled stream whose pollutants are attributed tocontributing streams inproportion to the flow rates ofthe contributing streams. Frequency Distribution

# - An arrangement or distribution of quantities pertaining toa single element inorder oftheir magnitude. Gauging Station

# - A location on a stream or conduit where measurements ofdischarse are customarily made. The location includes a stretch of channel through which the flow isuniform and a control downstream from this stretch. The station usually has a recording or other gauge formeasuring the elevation of the water surface inthe channel or conduit. Grab Sample 

# - A single sample ofwastewater taken at neither set time nor flow. Grease 

### - Inwastewater, a group ofsubstances including fats, waxes, free fattyacids, calcium and magnesium soaps, mineral oils, and certain other nonfatty materials. The type ofsolvent and method used for extraction should be stated for quantification.

### DRAFT
Grease Skimmer

# - A device for removing floating grease or scum from the surface ofwastewater ina tank. Grit

# - The heavy matter inwater orsewage such as sand, 

# -gravel and cinders. GritChamber 

# - A detention chamber oran enlargement ofa sewer desiqned to reduce the velocity of flow ofthe liquidto permit the separation ofm3neral from organic solids by differential sedimentation. Hardness

# - A characteristic ofwater, imparted by salts of calcium, maqnesium, and iron such as bicarbonates. carbonates,-sulfates, chlorides, and nitrates that cause curdling of soap, deposition of scale inboilers, damage insome industrial process, and sometimes objectionable taste. It

### may be determined by a standard laboratory procedure or computed from the amounts ofcalcium and magnesium as well as iron, aluminum, manganese, barium, strontium, and zinc, and is expressed as equivalent calcium carbonate. Heat ofAdsorption

# - The heat given offwhen molecules are adsorbed. Heavy Metals

# - A general name given tothe ions ofmetallic elements such as copper, zinc, chromium, and aluminum. They are normally removed from a wastewater forming an insoluble precipitate (usually a metallic hydroxide). Hook Gauge 

# - A pointed, U-shaped hook attached to a graduated staff orvernier scale, used inthe accurate measurement ofthe elevation ofa water surface. The hook issubmerged, and then raised, usually by means ofa screw, until the pointjust makes a pimple on thewater surface. Hydraulic Surge 

# - A pressure increase ina pipelinewhich accompanies a sudden decrease inthe flowvelocity. Insome cases this increased pressure may cause ruptureofthe pipe. Industrial Wastes 

# - The liquidwastes from industrial processes as distinct from domestic 

### or sanitarywastes. Incineration

# - The combustion (by burning) oforganic matter inwastewater sludge solids after water evaporation from the solids.

### DRAFT 

### Index, Sludge 

# - The volume ofmillilltersoccupied by aerate'd mixed liquor containing 1gram of dry solids after settling 80min. commonly referred to as the Mohlman index. The Donaldson index which is also commonly used isobtained by dividing 100 by the Mohlman index. Influent

# - Sewage, water 

### or other liquid, either raw 

### or partly treated, flowing into a reservoir basin, or treatment plant or any part thereof. Invert

# - The floor, bottom or lowest 

### portion of the internal cross section of 

### a closed conduit. Iodine Number (Activated Carbon) 

# - The iodine number is

### the mi'lliliterof iodine adsorbed 1 gram 

### of carbon at

### a filtrateconcentration of 0.02~-iodine. Ionization

# - The process of the formation of 

### ions by the splitting of molecules of electrolytes in

### solution. Irrigation Spray

# - Irrigation by means of nozzles along 

### a pipe 

### on the ground or from perforated overhead pipes. Lagoon 

# - (1) 

### A 

### shallow body of water as a pond or lake', which usually has a shallow, restricted inlet from the sea. (2) A pond containing raw or partially treated wastewater in which aerobic 

### or anaerobic stabilization occurs. Lime

# - Any of a family of chemicals consisting essentially of calcium hydroxide made from limestone (calcite) which 

### iscomposed almost wholly of calcium carbonate 

### or amixture of calcium and,magnesiumcarbonates. Liquor, Mixed 

# - A 

### mixture of activated sludge and sewage in

### the aeration tankundergoing activated sludge treatment. Liquor, Supernatant

# - (1) The liquor overlying deposited solids. (2) the liquid in a sludge digestion tank which liesbetween the sludge atthe bottom and the floating scum atthe top. 

### Loss of Head Gage 

# - A 

### gage on a rapid sand filterwhich indicates the loss of head involved in

### the filtering - 

### operationwhereby the operator isable to ascertain the need for filterbackwashing.DRAFT Macropore

# - The pores inactivated carbon which are larger (diameter) than 1.000A. Makeup Carbon

# - Fresh granular activated carbon which must be added toa column system after a regeneration cycle orwhen deemed necessary to bring the total amount of carbon tospecification. Manometer 

### - An instrument for measuring pressure. It usually consists of a U-shaped tube containing a liquidthe surface ofwhich isone end ofthe tube moves proportionallywith changes inpressure on the liquid inthe other end. Also, a tube type of differential pressure gauge. MeanVelocity 

# - The average velocity of a stream flowing in a channel orconduit ata given cross section or ina given reach. It isequal tothe discharge divided by the cross sectional area ofthe reach. Also called average velocity. Mesh Size (Activated Carbon).- The particle size ofgranular activated carbon as determined by the U.S. Sieve series. Particlesize distributionwithin a mesh series is given inthe specification ofthe particular carbon. Methylene Blue Number (Activated Carbon) 

# - The methylene blue number isthe milligrams ofmethylene blue adsorbed by 1 gram of carbon inequilibrium with a solution ofmethylene blue having a concentration of 1.0 mg/l. MethylorangeAlkalinity 

### - A measure of the total alkalinity ofan aqueous suspension orsolution. 

### It ismeasured by the quantity of sulfuric acid required to bring the water pH toa value of

### 4.3 as indicated by the change incolor of methyl orange. It isexpressed inmiligramsCaC03' per 1

### i ter. Micropore 

### - The pores inactivated carbon which range in size (diameter) from 10 to 1,000 A. MilligramsPer Liter (mg/l) 

# - This isa weight per volume designation used inwater and wastewater analysis. Mixed Media Filtration

### - A filterwhich uses 2 ormore filter materials ofdifferinqspecific qravities selected so -. 

### - as to produce a filter uniformly graded from coarse fine.

### DRAFT Monitoring

# - (1) The procedure or operation of locating and measuring radioactive contamination by means of survey instruments that can detect and measure, as dose rate, ionizing radiations. (2) The measurements sometimes continous, ofwater quality. Most Probable Number (MPN) 

### - That number of organisms per unitvolume that, inaccordance with statistical theory, would be more likelythan any other number t o y i e l dthe obserbed test result with the greatest frequency. Expressed as the organisms per 100

### ml. Results are computed from the number of positivefindings of coliform-group organisms resulringfrom mu1tiple-portion decimal-dilution plantings. Nappe 

### - The sheet orcurtainofwater overflowing a weir or dam. When freely overflowing any given structure, it

### has awell-defined upper and lower surface. Neutralization

# - Reaction of acid or alkali with the opposite reaqent until the concentrations of hydrosen and hydroxyl-ions insolution are approximately eqial. Nitrification

# - The conversion of nitrogenous matter into nitrates by bacteria. Nonionic Surfactant

# - A general family ofsurfactants so called because insolution the entire molecule remains associated. Nonionic molecules orient themselves atsurfaces not by an electrical charge, but through separate grease-solubilizing and water-soluble groups within the molecule. Nonsettleable Matter 

### - The suspended matter which does not sett1.e nor float to the surface of water ina period of one hour. Nonsettleable Solids

# - Wastewater matter thatwill 

### stay in suspension for an extended periodof time. Such periodmay be arbitrarilytaken for testing purposes as one hour. Notch

# - An opening in

### a dam, spillway, or measuringweir for the passage ofwater.

### DRAFT Nozzle 

# - (1) A short, cone-shaped tube used as an outlet for a hose or pipe. The velocity of the merging stream of water is increased by the reduction in cross sectional area of the nozzle (2) 

### a short piece of pipe with a flange on one end and a saddle flange on the other end. Nutrients 

### - Materials which are considered to be essential to support biological 1ife. Odor Control 

### - The elimination of odor-causing valatile substances associated with organic matter, living organisms, and cases. The most common, control measurement in use are the application of activated carbon residual chlorination, chlorine dioxide, ozone and 

### aeration. Odor Threshold 

# - The point atwhich after successive dilutionswith odorless water, the odor of a water sample can just be detected. 

## he threshold odor is expressed quantitativelyby the number of times the sample is diluted with odorless water. Oil and Grease 

# - Those materials which areextractable from wastewater with hexane, chloroform if other content of these specific solvents pollutants in water or wastewater (in mg/l or ppm) 

### which can significantly influence the environment. Open-Channel Flow

# - Flow of 

### a fluid with its surface exposed tothe atmos~here. The conduit may be an open channel

- - 

### or a closed conduit flowing partly"full. Op_erators Qua1 ifications, Treatment Plant 

# - Usually defined by 

### a licence issued by 

### local authorities. Organic Matter 

### - Chemical substances of animal or vegetable origin, or more correctlyof basically carbon structure, comprising compounds consisting of hydrocarbons and theirdeviations. Organic Nitrogen 

### - Nitrogen combined in organic molecules such as protein, amines, and amino acids. Orifice

# - (1)

### An opening with closed perimeter, usually of regular form, in a plate, wall, or partition, through which water may flow generally used for the purpose of measurement orcontrol of such water. The edge may be sharpor of another configuration (2) 

### the end of a small tube such as a Pitot tube.

### DRAFT 

### QrificePlate

# - A 

### plate containing an orifice. In pipes, 

### the plate isusually inserted between a pair of flanges, and the orificeis smaller in area than the cross sectionof 

### the pipe. Orthophosphate 

# - An acid or saltcontaining phosphorus as PO4. Outfall 

# - The point or location where sewage or drainage discharges from a sewer, drain, or conduit. Overflow Storm 

# - A weir, orifice, or other device for permittinq the discharqe from,a combined sewer of that part of the flow in

### excess of that which the sewer 

### is designed tocarry. Oxidation 

# - The addition of oxygen toa compound. More generally, any reaction which involves 

### the loss of electrons from an atom. Oxidation Pond 

# - A 

### basin used for retention of wastewater before final disposal, in which biological oxidation of organic material iseffected by natural or artificallyaccelerated transfer of oxygen to the. water from air. Oxidation Reduction Potential (ORP)

# - The potential required totransferelectrons from the oxidant to the reductant and 

### used as a qualitative measure of the stateof oxidation in wastewater treatment systems. Oxygen Consumed 

# - The quantity of oxygen taken up from potassium permananganate in.solutionby a liquid containing organic matter. Commonly regarded as an index of the carbonaceous matter present. Time and temperaturemust be specified. Oxygen Dissolved

# - Usually designated asDO. 

### The oxygon dissolved-insewage wat'er, or other liquid usuqlly expressed in

### parts per million or percent of saturati on. Ozone

# - Oxygen 

### inmolecular form 

### with

### three atoms of oxygen forming each molecule. Atmospheric oxygsn 

### is in molecular form but each molecule contains two atoms of oxygen. Ozone isformed by passing high voltage electriccharges through dry air. The third atom of oxygen in

### each molecule of ozone is

### loosely bound to

### itand iseasily released.

### DRAFT 

### Parshall Flume 

# - A calibrated device developed by Parshall formeasuring the flow of liquid in an open conduit. Itconsists essentially of a contracting length, a throat, and an expanding length. At

### the throat is a sill over which the flow passes as critical depth. The upper and lower heads areeach measured ata definite distance from the sill. The lower head not be measured unless the sill is submerged more than about 67 percent. Pathogenic Bacteria 

# - Bacteria which may cause disease in the organisms by their parasitic growth. pH

# - The reciprocal of the logarithm of the hydrogen ion concentration. The concentration isthe weight of hydrogen ions, in grams per literof solution. Neutral water, for example, has a pH 

### value of 7and hydrogen ion concentration of 10.7. pH Adjustment 

# - A 

### means of maintaining the optimum pH 

### through the use of chemical additives. Can be manual or automatic, or automatic with flow corrections pH 

### adjustment isnot a linear function. Phenolein A1kalinity 

# - A 

### measure of the hydroxides ~lus one half of the normal carbonates in aqueous ;uspension. Measured by the amount of sulfuric acid required tobring the water to a pH 

### value of 8.3, 

### as indicated by a change in color of phenolphthalein. Itisexpressed in

### parts per million of calcium carbonate. Pitot Tube

# - A 

### device formeasuring the velocity of flowing fluid bv 

### usinq the ve1ocit.y head of the stream as an index velocity. Itconsists essentially of an orifice held to point upstream and connected with a tube in which the impact pressure due to velocity head may be observed and measured. Italso may be constructed with an 

### upstream and downstream orifice, or with 

### an orifice pointing upstream tomeasure the velocity head or pressure and piezometer holes in a coaxial tube to measure the statichead or pressure, in which case the difference in

### pressure is the index of velocity. Pollution Load 

# - A 

### measure of the strength of awastewater in

### terms of its solids or oxygen-demanding characteristics, or in terms of harm,toreceiving waters.

### DRAFT Pollution Water 

# - The introduction into a body ofwater of substances of such character and of such auantity that its natural quality is so altered as to 'impairw its usefulness or render it offensive to the senses of sight, taste, or smell. Polyelectrolytes 

# - Used as a coagulant or a coagulant aid in water and wastewater treatment (activated carbon is another coagulant aid). They are synthetic polymers having a high

### molecular weight. Anionic negatively charged. Nonionic carry both negative and positive charges,(Cationic postively charged (mostpopular). Pond, Sewaqe Oxidation 

# - A pond either natural or artifical into which partly treated sewageor discharged and in which natural purification processes take place under the influence of sunlight and air. Pooling, Filter

# - The formation of pools of sewage on the surface of filters,caused by surface cloggings. PoreVolume (activated carbon)

# - The pore volume is

### the difference in the volumetric displacement by granular activated carbon in mercury and 

## in helium at standard conditions. Preaeration 

# - A preparatory treatment of sewage consisting of aeration to remove gases,add oxygen, or promote flotation of grease and aid coagulation. Prechlorination

# - (1) Chlorination ofwater prior to filtration. (2) 

### Chlorination of sewage prior to treatment. Precipitation,chemical 

# - (1) Precipitation induced by addition of 

### chemicals (2) 

### Theprocess of softening water by the addition of lime and soda ash as the precipitants. Pretreatment 

# - Any wastewater treatment process used to reduce pollution load partially before the wastewater is introduced into amain sewer system or delivered to a treatment plantbforsubstantial reduction of the pollution load. Primary Treatment

# - A 

### process to remove substantlally all floating andsettleablesolids in wastewater and partially to reduce the concentration of suspended solids.

### DRAFT 

### Probability Curve

# - A 

### curve that expresses the cumulative frequency of occurrence of 

## a given event, based on an extended record of past occurrences. The curve is usually plotted on specially prepared coordinate paper, with

### ordinates representing magnitude equal to, or lessthan, the event, and abscissas representing the probability, time, or other units of incidence. Process Activated Sludge 

# - A 

### biological sewage treatment process in which a mixture of sewage and activated sludge isagitated and 

### aerated. 

## he activated sludge issubsequentlyseparated from the treated sewage (mixed liquor) by sedimentation, and wasted or returned tothe process as needed. The treated sewage overflows theweir of the settling tank in which separation from the sludge takes place. Process, Biological

# - The process by which the lifeactivities of bacteria, and 

### other microorganisms in thesearch for food break down 

### complex organic materials into simple, more stable substances. Self-purification of sewage polluted streams, sludge digestion, and all so-called secondary sewage treatments result from this process. Also called biochemical process. Process, Oxidation

# - Any method of sewage treatment for the oxidation of the putrescible organic matter the usual methods arebiological filtration, and the activated sludge process. Purification Degree

# - (1) 

### A 

### measure of thecomp'letenessof destruction or removal of objectionable impurities. such as bacteria and hardness from water by natural means (self urifications]or'bytreatment (2)A 

### measure of

# ! he removal, oxidation, or 

### destruction of solids organic matter, bacteria, or other specified substance effected by sewage treatment processes. Putrefaction 

# - Biological decomposition of organic matter 

# - accompanied by 

### the production of foul-smelling associated with anaerobic conditions. Rate Oxidation 

# - The rate at

### which the organic matter in 

### sewage is stablized. Ratio Dosinq 

# - The maximum rate of application of sewage toa filter

### on any unit of area, divided by the average rateof application 

### on,that area.

### DRAFT Reactivation (activated carbon)

# - The removal of adsorbates from spent granular activated carbon which will allow the carbon to be reused. This isalso called regeneration and reviyification. Reaeration Sludqe

# - The continous aeration of sludge after 

### itsintial aeration in the activated sludge process. Recirculation

# - The refiltration of all or a portion of the effluent in a high rate trickling filterfor the purpose of incoming flow to reduce its strength. Reduction Overall 

# - The percentage reduction in the final effluent as compared with the raw sewage.

enation

# - The replenishment of oxygen in

### a stream 

### R* 1 dilution water entering the stream (2) 

### biological oxygenation 

### through the activitiesof certain oxygen producting plants and (3) 

### atmospheric reaeration. Reservoir

# - A 

### pond, lake, tank, basin, 

### or other space eithernatural in

### origin or created inwhole or in part by building of engineering structures. Itis used for storage, regulation, and control of water. Recorder

# - A 

### device that makes a graph or other automatic record of the stage, pressure, depth, velocity, or themovement orposition of water controlling devices, usually as a function of time. Recovery Products

# - Substances regarded as wastewater pollutants which are recovered for their potential value through saleorreuse; recovery often isused -tolower or partially offset treatment (or recovery) costs. Rectangular Weir

# - A 

### weir having a notch that isrectangularin shape. Reduction Practices

# - (7) 

### Wastewater reduction practices can mean the reduction of water usage to lower the volume of wastewater requiring treatment and (2) the 

### use of chemical reductantmaterials tolower the valance stateof a specificwastewater pollutant. Reduction Treatment

# - The opposite of oxidation treatment where in 

### a reductant (chemical isused tolower the valence stateof a poilutant to a less toxic form e.g, 

### the use of 

### SO2 to "reduce" chromium +6 to chromium +3 

### inan acidic solution.

### DRAFT 

### Refractory Organics

# - Organic pollutants which are chemically quite stableor resistant totreatment 

### or biological oxidation, e.g. DDT 

### pesticide. Residual Chlorine

# - Chlorine remaining in

### water orwastewater atthe end of specified contact period as combined or free chlorine. Salinity

# - (1)The relative concentration of salts, usually sodium chloride, in a given water. It isusually expressed in terms of the number of parts per million of chloride (C1). (2) A 

### measure of the concentration of dissolved mineral substances in water. Sampler 

# - A 

### device used with or without flow measurement toobtain an aliquot portion of water 

### or waste for analytical purposes. May be designed for taking a sing1e sample (grab), composite sample, continous sample, periodic sample. Sanitary Sewer 

### - A 

### sewer that carries liquid and watercarriedwastes from residences, commercial buildinqs, 

### - - 

### industrial plants, and institutions together with 

### minor quantities of ground-storm, and surface waters that arenot admitted intentionally. Screen 

# - (1)A devicewith openings, generally of uniform size, used toretain or remove suspended or floating solids in flowing water orwastewater and to prevent them from entering an intake or passing a given point in a conduit. The screening element may consist of para11 el bars, rods, wires

## ,grating, wire mesh, or perforated plate, and the openings may be of any shape, although they are usually circular or rectangular. (2)A 

### device used to segregate granular material such as sand, crushed rock, and soil into various sizes. Secondary SettlingTank 

# - A 

### tank through which effluent from some prior treatment process flows for the purpose of-removing settleable solids. Secondary Wastewater Treatment

# - The treatment of wastewater by biological methods after primary treatment by sedimentation. Second Stage Biological Oxygen Demand 

# - That part of the oxygen demand associated with the biochemical oxidation of nitrogenous material. As the term implies, the oxidation of the nitrogenous materials usually does not startuntil a portion of the carbonaceous material has been oxidized during the first stage.DRAFT Sedimentation 

### - The process of subsidence and deposition of suspended matter carried by water, wastewater, or other liquids, by gravity. It isusally accomplished by reducing the velocity ofthe liquid below the point atwhich itcan transport the suspended material. Also called settling. Seeding Sludge

# - The inoculation of undigested sewage solids with sludqe that has underqone decomposition for the purpose of introducing favorable organisms, thereby accelerating the intial stages ofdigestion. Sewage Combined

# - A sewage containing both sanitary sewage and surface or storm water with orwithout industrial wastes. Sewage Dilute

# - Sewage containing less than 150 ppm of suspended solids and BOD (weak sewage). Sewage Industrial

# - Sewage inwhich industrial wastes predominate. Sewage Raw 

# - Sewage prior to receiving any treatment. Sewage Settled

# - Sewage from which most ofthe settleable solids have been removed by sedimentation. Sewage Storm

# - Liquid flowing 

### insewers during or following a period of heavy rainfall and resulting therefrom. Sewer 

# - A pipe or conduit, generally closed, but normally not flowing full for carrying sewage and other waste 1iquids. Sewer Intercepting

# - A sewer which receives dry-weather flow from a number of transverse sewers or outlets, and fequently additional, predetermined quantities of storm water (iffrom a combined system) and which conducts such waters toa point for treatment or disposal. Semipermeable Membrane

# - A barrier, usually thin, that permits passaqe of particles up to a certain size orof special nature. 'Often used'to separate colloids from their suspending liquid, as indialysis.

### DRAFT


### SettleableSolids

# - (1) That matter in wastewater which will not stay in suspension during a preselected settling period, such as one hour, but either settles to the bottom or floats to the top. (2) 

### In the Imhoff cone test, thevolume of matter that settles to the bottom of the cone in one hour. Skimming Tank 

# - A tank so designed that floatingmatter will rise and remain on the surface of the wastewater until removed, while the liquid discharges continously under certainwalls or scum boards. Sludge

# - The solids (and accompanying water and organic matter) which are separated from sewage or industrial wastewater in treatment plant facilities. Sludge separation and disposal is one of the major expenses in

### wastewater treatment. Sludge Conditioning

# - A process employed to prepare sludge for final disposal can be thickening, digesting, heat treatment etc. Sludge Digestion

# - The process by 

### which orqanic or volatile matter in sludge isgasified,liquified, mineraliz'ed, or converted intomore stable organic matter through the activitiesof either anaerobic or aerobic organisms Sludge Disposal 

# - The final disposal of solidwastes including theuse of sewage sludges as fertilizers and soil builders; dumping sludge atsea; and fillinglowlying lands. Sludge thickening

# - The increase,insolids concentration of sludge in

### a sedimentationor digestion tank. Spills

# - A 

### chemical ormaterial spill isan unintentional discharge of more than 10 percent of the sewage daily usage of a regularly used substance. In the case of

### a rarely used (one per year or less) chemical or substance, a spill isthat amount that would result in

### 10%added loading to the normal air, water or solid waste loadings measured as the closest equivalent pollutant. Stabilization Laqoon 

# - A 

### shallow pond for storage of wastewater before discharge. Such lagoons may serve only todetain and equalize wastewater composition before regulated discharge 

### toa stream, but 

### often they are used forbiological oxidation.

### DRAFT 

### Stabilization Pond

# - A 

### type of oxidation pond in which biological oxidation of organic matter 

### is effected by natural or artificallyaccelerated transfer of oxygen tothe water from air. Staff Gauge 

# - A 

### graduated scale, vertical unless otherwise specified, on a plank, metal plate, pier, wall etc., used to indicate the height of a fluid surfaceabove 

### a specified point or datum plane. ,StageDischarge Relation

# - The relation between gauge height and discharge of a stream or conduit ata gauging station. This relation is shown by the rating curve orrating table for such stations. Static Head 

# - (1) The total head without reduction for velocityhead or losses; for example, the difference 

### inthe elevation of headwater and tail water of a power plant. (2) 

### The vertical distance between the freelevel of the source of supply and 

### the point of freedischarge or the level of the free surface. Steady Flow

# - (1) A 

### flow in which the rate or quantity of water passing a given point per unit of time remains constrant. (2) 

### Flow in which the velocity vector doer not change in

### eithermagnitude or direction with respect to time atany point or section. SteadyUniform Flow 

# - A flow in which the velocity and the quantity of water flowing per 

### unit remains constant. StillingWell 

# - A 

### pipe, chamber, or compartment with compartively small inlet or inlets communicating with a main body of water. Its purpose istodampen waves 

### or surges, while permitting the water level within 

### thewell torise and fall with themajor fluctations of themain body of water. Itisused with

### watermeasuring devices to improve accuracy of measurement. Submerqed Weir 

# - A 

### weir that when in use, has the water level on the downstream side atan elevation equal toorhigher than, the weir crest. The rate of discharge isaffected by the tail water. Also called drowned weir. Suppressed Weir 

# - A 

### weir with one or both sides flush with 

### thechannel of approach. This prevents contraction of the nappe adjacent to the flush side, The suppressionmay occur on one end or both ends.

### DRAFT 

### Surveys 

# - The gathering of numerical and other forms of data from the field, or plant sitefor the subsequent purpose of data reduction, correlation and analysis leading to improve water supply, treatment, use and wastewater treatment, described in

### total as a Water Management Program. Suspended Matter

# - (1) Solids in suspension in water, wastewater or effluent. (2) Solids in suspension that can be removed readily by standard filtering procedures in a laboratory. Suspended Solids

# - (1) Solids that either float

### on the 

### - surface of, or are in suspension in water, wastewater, or other liquids, and which are largely removable by - 

### laboratory filtering. (2)The quantity of material removed from wastewater in a laboratory test, as prescribed in "Standard Methods for the Examination of Water and Wastewater" and referred to as nonfilterableresidue. Tertiary Treatment 

### - A process toremove practically all solids and orsanicmatter from wastewater. Granular activated carbon filtration isa tertiary treatment process. Phosphate removal by chemical coagulation isalsoregarded as a step in

### tertiary treatment. Threshold Odor 

# - The minimum odor of the water sample that can

### just be detected after successive dilutions with odoriess water. Also called odor threshold. Titra.tion

# - The determination of a constituent in a known volume of solution by themeasured addition of a solution of known strength tocompletion of the reaction as signaled by observation of an end point. Total Organic Carbon (TOC) 

### - TOC 

### isa measure of the amount of carbon in

### a sample orisinatins from orsanic matter only. The test is

### run by burningVthesampieand measuring the CO 

### produced. Total Solids 

### - The 

### total amount of solids in a waste water in

### both solution and suspension. Tracer

# - (1) A 

### foreign substance mixed with 

### or attached to a given substance for the determination of the location ordistribution of the substance. (2)An element or compound that has been made radioactive sothat it can be easily followed (traced) in biological and industrial processes. Radiation emitted by the radioisotope pinpoints itslocation.

### DRAFT Treatment Efficiency

# - Usually refers tothe percentage reduction ofa specific or group of pollutants by a specificwastewater treatment step or treatment plant. Turbidmeter 

# - An instrument for measurement ofturbidity, in which a standard suspension usually isused for reference. Turbidity

# - (1) A condition inwater orwastewater caused bythe presence.of suspended matter, resulting inthe scattering and absorption of light rays. 

### (2) A measure offinesuspended matter inliquids. (3) 

### An analytical quantity usually reported inarbitrary turbidity units determined by measurements of lightdiffraction. Turbulent Flow

# - (1) The flowof a liquid past an object such that the velocity atanv fixed point inthe fluid varies irregularly. 

## (2)A type of liquidflow inwhich there isan unsteady motion ofthe particles and the motion ata fixed pointvaries inno definitemanner. Sometimes called eddy flow, sinuous flow. Ultimate Biochemical Oxygen Demand

# - (1) Commonly, the total quantity ofoxygen requiredtosatisfycompletely the first-stage biochemical oxygen demand. (2) 

### More strickly, the quantity ofoxygen required tostatisfy completly boththe first-stage and the second-stage biochemical oxygen demands. VelocityArea Method

# - A method used todetermine the discharge ofa stream or any open channel by measuring the velocityofthe flowing water atseveral points within the cross section ofthe stream and summing up the products ofthese velocities and their respective fraction ofthe total area. Velocity Meter

# - Awater meter that operates on the principlethat the vanes ofthe wheel move at approximately the same velocityas the flowing water. Velocity ofApproach

# - The mean velocity ina conduit immediately upstream from aweir, dam, venturi tube, or other structure. Vena Contracta

# - The most contacted sectional area ofa streamjet, or nappe issuing through or over an orifice orweir notch. 

### It occurs downstream from the plane ofsuch notch ororifice.

### DRAFT

Venturi Flume

# - A open flume with a contracted throat that causes a drop inthe hydraulic grade line. It 

### isused for measuring flow. Venturi Meter

# - A differential meter formeasuring flow of water orother fluidthrough closed conduits of pipes, consisting ofa venturi tube and one ofseveral proprietary forms of flow-registering devices. The difference invelocity heads between the entrance and the contracted throat isan indication ofthe rateof flow. Venturi Tube 

# - A closed conduit or pipe, used tomeasure the rateoffluids, containing a gradual contraction toa throat, which causes a pressure-head reduction by which the velocity may be determined. The contraction isusually, but not necessarily, followed by an enlargement tothe original size. Volatile Solids

# - The quantity ofsolids inwater, wastewater or other liquids, loston ignitionofthe dry solids at

### 600°C. Wastewater Survey

# - An investigationofthe qualityand characteristics ofeach waste stream, as inan industrial plantormunicipality. Water Level Recorder

# - A device for producing, graphically or otherwise, 

### a record ofthe riseand fall of

### a water surfacewith respect totime. Water Meter

# - A device installed ina pipe under pressure for measuring and registeringthe quantity ofwater passingthrough it. 

### Water Renovation

# - Wastewater treatment of sufficient degree toallow the reuse ofwater for one or more purposes ina given water supply/treatment system. Weir

# - (1) A diversion dam. (2) A device that has a crest 

### and some side containment of known geometric shape, such as a 

### V, trapezoid, or rectangle and isused to measure flow of liquid. The liquidsurface isexposed tothe atmosphere. Flow is related to upstream height ofwater above the crest, to position ofcrest with respect todownstream water surface, and togeometry ofthe weir opening.DRAFT APPENDIX C

EFFECT OF POLLUTANT PARAMETERS 

### ON TREATMENT WORKS



### pH, ACIDITY AND ALKALINITY

Most bacteria (and other protists) that are essential to the operation ofa biological treatment system cannot bear pH levels above 

### 9.5 or below 5.0. The pH range for optimum growth generally lies between 6.5 and 

### 7.5. Depending on the volume of a particularwaste and the acidity or alkalinity ofthe waste inthe treatment unit, an incoming waste of extreme pH could have a substantial adverse effect on a treatment unit. Acidity Highly acidwastes can exhibit the same detrimental effects on microorganisms as wastes of low pH. The acidity of an incoming waste isparticularly important inoperation of anaerobic digesters, where the pH for optimum operation is 

### 6.6 to 7.6. An incomingwaste of high acidity that causes the pH of an anaerobic system to drop below 6.2 will severely upset operation of the unit. Wastes of high acidity are also corrosive to the metals and concrete that make up the structure of any treatment unit. Alkalinity 

### A waste of high alkalinity can have a severe effect on the operation of a treatment unit, not only causing the death of microorganisms, but also causing the corrosion of structural materials. OIL 

### AND GREASE 

### -- Oils and grease can cause problems with scum formation in wet wells and clarifiers. Mineral oils inparticular can coat solid particles that are present inwastes. The particles hinder biological activity and increase maintenance problems. Free oil (as measured by

## CC74extraction) has reportedly interfered with aerobic biological treatment at concentrations of 50-100 mg/l (1).DRAFT CHEMICAL OXYGEN DEMAND (COD) Since the COD analysis issensitive to compounds that are toxic tobiological life as well as those that are not, a waste of high COD can be potentially harmful totreatment systems 

### iftoxins are present. The potential for harm ofa high COD waste would remain unknown without either detailed chemical analysis of the waste or experimentation with the waste on 

### a laboratory-scale biological treatment system. CHROMIUM (Cr) Moore, 

## et

# a (2), have studied the effects of hexavalent chromium (in the form of potassium chromate) on laboratory-scale activated sludge systems and laboratory scale anaerobic digesters. Their results for activated sludge systems showed that continuous Cr+6 concentrations atand below 15 mg/l inthe sewage feed had no significant effect on overall BOD and COD removal. 

### A continuous dose of 50 mg/l of Cr+6 reduced BOD removal efficiency by three percent over that of a control unit and COD removal efficiency by four percent, but the authors attach limited significance tothis result. Continuous doses of chromium containing primary and secondary sludge from the activated sludge system to the anaerobic digesters had no effect on anaerobic gas production at concentrations of

## Cr+6 inthe sludge of 3.0 mg/l, 

### 5.8 mg/l, and 30 mg/l. The authors also studied the effects of slug doses of Cr+6 on the aforementioned.systems. The sludge doses were fed tothe activated sludge systems over a four hour period of time inthe amounts of 10 mg/l, 100 mg/l and 500 mg/l. No effect on performance was noted with the 10 mg/l dose. The I00mg/l dose caused a drop of three percent inthe BOD removal efficiency and a greater drop inthe COD removal efficiency, with a rapid recovery. The 500 

### mg/l dose caused a drop in BOD removal efficiency of 11 percent and a drop inthe COD removal efficiency of 13 percent. The decreased efficiency lasted for 32 hours, and was followed by a gradual recovery. Slug doses were also added todigesters that had previously received chromium containing sludge. 

### A slug dose of 300 mg/l caused gas production to cease for seven days, followed by gradual recovery. A slug dose of 500 mg/l ceased gas production permanently. The authors point out that the likelihoodofdigesters receiving slug doses of these magnitudes isextremely remote.DRAFT The authors' results also show that the removal efficiency of chromium by the activated sludge process can vary greatly, depending on the chromium concentration inthe influent. Reported 

## Cr+6 removals varied from approximately 78 percent to 17 percent when the

## Cr+6 influent concentrationwas 50.0 mg/l to 0.5 mg/l respectively. Other researchers have performed studies on nitrification. Whiteland, 

# et (I), ina study of the effects of hexavalent chromium on the nitrification process, have reported that the process was severely affected at

## Cr+6 concentrations inraw sewage on the order of 2 mg/l to 

### 5 mg/l. COPPER (Cu) McDermott, -- et a1 (2), have investigated the effects of copper inthe form of copper sulfate and inthe form of a copper cyanide complex (Nan Cu(CN)n) on bench scale activated sludge systems and-bench scale anaerobic digesters. Studies were conducted on the effects of both continuous and slug doses of these two forms of copper on BOD and COD removal efficiency of the activated sludge systems, and on the effects of continuous doses of copper sulfate, continuous doses of copper cyanide complex, and slug doses of copper sulfate on gas production from the anaerobic digesters. The results for continuous doses toactivated sludge systems showed that 10-25 mg/1 ofcopper sulfate 

### inthe influent reduced BOD and COD removal efficiency by an average of four percent, and that 5-10 mg/l 

### of the copper cyanide complex reduced BOD and COD removal efficiency by as much as six percent. Differences ineffects of the two forms of copper disappeared after the system acclimated to the copper and cyanide. Slug doses of copper sulfate to the activated sludge system of 66 mg/l over a four-hour period had only a small effect on BOD and COD removal efficiency, but doses of 100 mg/l caused a 50 percent reduction inBOD removal efficiency and larger doses up to410 mg/l had somewhat greater effects. All of the systems recovered after a maximum of 120 hours. Smaller slug doses of the copper cyanide complex had a much more severe initial effect than the copper sulfate, but the systems recovered inonly 24 hours with doses up to25 mg/l. Anaerobic digesters that were fed combined primary and secondary sludge from activated sludge units that were receiving 10-25 mg/l of copper sulfate and 10 mg/l of the copper cyanide complex experienced subnormal gas production. Slug doses of copper sulfate of as much as 410 mg/l had no effect on digester performance. The authors also report that the activated sludge process is79 to 50 percent efficient inthe removal of both forms of copper whenDRAFT the copper concentration inthe influent is0.4 to

### 25 mg/l. Studies on the effect of copper on the nitrification process have been conducted by Kalabina, 

### -- eta1 (1). The authors report that copper at concentrations of0.5 mg/l inhibited nitrificationwhen the copper was fed inthe form of copper sulfate. CYANIDE (CN) It has been reported that 1.0-2.0 mg/l of cyanide (as HCN) in influent sewage had an effect on the performance of activated sludge units, trickling filters, and anaerobic digesters, and that 2.0 mg/l of cyanide inhibited the nitrification process. Higher levels of tolerance of activated sludge units and trickling filters have been reported by other authors. Interferencewith the activated sludge process has been reported at cyanide concentrations inraw sewage of 

### 5 mg/l. Studies on trickling filter performance have reported that 30 mg/l ofcyanide inthe influent to trickling filters produced an effluent of poor quality, but that cyanide concentrations of 10 mg/l can be destroyed almost completely. Other studies have reported that secondary biological treatment processes, ifacclimatized to cyanide, can effectively oxidize it (1). IRON (Fe) -- Iron isa necessary nutrient for microbial growth, and has no effect on the activated sludge process except at very high concentrations (on the order of 1000 mg/l). The effect of iron on the sludge digestion process has been reported (to be much greater. Iron levels above 5 mg/l indigesters have caused interference with the process, due to the release of acidity when the iron ishydrolyzed (3). NICKEL (Ni) McDermott, et a1 

### (2) have conducted studies on the effect of nickelsulfate additions to bench scale activated sludge units and anaerobic digesters. Continuous doses of nickel toactivated sludge units ranging from 2.5-10 mg/l reduced BOD removal efficiency by a maximum of five percent and increased the turbidity ofthe effluent. 

### A 200 mg/l slug dose of nickel seriously reduced treatment efficiency for a few hours, but the activated sludge process recovered completely within40 hours. Combined primary and secondary sludge from an activated sludge process receivingDRAFT 10 mg/l of nickel digested satisfactorily inanaerobic digesters, and primary sludge from a unit receiving 40 mg/l continously digested satisfactorily. Itwas reported that the activated sludge process isapproximately 30 percent efficient inthe removal of nickel. With respect to nitrification, 

### it has been reported that severe inhibitionof the process isexperienced at a nickel concentration of 0.5 mg/l (1). PHOSPHORUS Phosphorus isnot harmful totreatment works, and is actually a necessary nutrient for adequate bacterial growth. 

### If phosphorus isnot completely removed during wastewater treatment, however, itcan have harmful effects upon the receiving water (as discussed under Section VI). 

### ZINC (Zn) McDermott, eta1 

### (Z), have reported the effects of zinc on activated sludge treatment and anaerobic digestion. Zinc sulfate and zinc complexed with cyanide had similar effects when fed continously to a laboratory-scale activated sludge process. 

### Atconcentrations ranging from 2.5 to20 mg/l both substances reduced BOD removal efficiency by a maximum of two percent after the activated sludge became acclimated. The maximum zinc concentration that

### will produce no significant effect on treatment efficiencywas reported as greater than 2.5 mg/l and less than 10 mg/l. 

### A 160 mg/l slug dose of zinc fed to the activated sludge unit over a period of four hours caused a drastic reduction intreatment efficiency for about one day, but the unit recovered completely after 40 hours. Combined primary and secondary sludge from activated sludge units receiving 10 mg/l of zinc continuously (as ZnS04) digested suitably inanaerobic digesters. Sludge from-activated sludge units that were fed 20 mg/l caused rapid failure of the digestion units. The activated sludge process is reported as being from 95 to 74 percent efficient inremoving zinc when fed sewage with zinc concentrations from 2.5 mg/l to 20 mg/l respectively. Other authors have reported that the concentration of zinc ininfluent sewage should be less than 

### 5 mg/l to prevent decreases ingas production inanaerobic digestion, and that zinc concentrations of 0.5 mg/l will inhibit the nitrification process 

### (1).DRAFT SYNERGISM AND ANTAGONISM Synergism The increase inthe toxic effect of one substance caused by the presence ofanother substance iscalled synergism. Synergistic effects are particularly important when considering metals, since most metals are soluble at low pH values and insoluble at high pH values. Thus acidity can exert a synergistic effect by contributing tothe release of metals into solution, where they can be ingested by microorganisms. Reference 

### 3 contains a discussion of the synergistic effects of cadmium, chromium, copper, iron, and zinc, which issummarized below: Cadmium 

### - Zinc and manganese have been reported to have synergistic effectswith cadmium. It iscertain that acidity would also have a synergistic effect. Chromium 

### - Iron, copper, and acidity have been reported to have synergistic effects with chromium. Copper 

### - Synergismwith cyanide, acidity, and other heavy metals has been reported. Iron

# - Synergism of ironwith chromium has been reported and synergistic effects with other metals may also occur. Zinc

# - Synergistic effects have been reported with the following: 10 mg/l 

### of cadmium with 1mg/l of zinc, 10 mg/l of cadmium with 10 mg/l of zinc, and 100 mg/l of manganese with 10 mg/l of zinc. Antagonism Antagonism isthe opposite of synergism, and isthus the decrease inthe toxic effect of one substance caused by the presence ofanother. Dramatic antagonistic effects on metals are caused by chelating agents, ofwhich EDTA (disodium salt of ethylene diamine tetracetic acid) and HEDTA (disodium salt of hydroxyethylenediamine triacetic acid) are examples. Sulfide can exhibit antagonistic effects with metals in sludge digesters. This effect isprobably responsible for much ofthe ambiguity inthe literature ofthe effects of metals on sludge digestion. The, antagonistic effect isdue tothe fact that sulfide precipitates metals, thus taking them out of solution, and preventing their assimilation by microorganisms. Other ions have similar effects on

### DRAFT metals; examples are: hydroxide (high pH), chromate, ferrocyanide, phosphate, carbonate, and arsenate (17). A summary of the antagonistic effects of cadmium, copper, and iron follows: (3). 

### Cadmium 

### - Sulfide and high pH (8

### and higher) are antagonistic 

### wth cadmium. Copper 

# - Sulfide, high pH and certain chelating agents (such as 

### EDTA) are antagonistic 

### with copper. Iron

# - Sulfide and high 

### pH are antagonistic with iron. Additionally, an antagonistic effect would be expected with cyanide, since the ferrocyanide complex is very stable.

### DRAFT 

### REFERENCES

1. U.S. Environmental Protection Agency, "Pretreatment of pollutants introduced into publicly-owned 

### - treatment works, Office of Water Program Operations, Washington, D.C., 

### (October, 1973). 2. 

### U.S. Department of Health, Education and Welfare, Interaction of Heavy Metals and Biological Sewage Treatment Processes, Pub1icHealth Service, Division of Water Supply and Pol1

### ution Control, Cincinnati, Ohio (May, 1975). 3. U.S. 

### Environmental Protection Agency, Stateand Local Pretreatment Programs, (Draft Federal Guidelines), Office of Water Program Operations, Washington, D.C., 

### (August, 1975).METRIC UNITS CONVERSION TABLE
MULTIPLY (ENGLISli UNITS) by ENGLISH UNIT

acre acre

# - feet BritishThermal

Unit BritishThermal

Unic/pound cubic feet/minute cubic feet /second cubic feet cubic feet cubic inches degree Fahrenheit feet gallon gallon/minute horsepower inches inches of mercury pounds million gallons/day mile poundlaquare inch (gauge) square feet square inches tons (ehort) yard ABBREVlATXON CONVERSION

ac ac ft BTU BTU/~ cfm cfs cuft cu ft cu in Fa ft gal gpm hp in inHg lb mgd mi psi8 sqft sqin t Y TO OBTAIN (METRIC UNITS)
ABBREVIATION

kg cal

(0.06805 psig-1-1)" 0.0929 6.452 0.907 0.9144 

## * Actual conversion, not a multiplfet "C m 1 l/sec kw cm atrn kg cum/day km

atm sq m sqcm kkg m METRIC UNIT hectares cubicmeters kilogram

### - calories kilogram calories/l:ilogxa~n cubic tneters/minute cubicmeters/minute cubicmeters liters cabic centimeters degree Centigrade meters liters lfters/second killowatts centimeters atmospheres kilograms cubicmeterslday kilometer atmospheres (absolute) squaremeters square centimeters metric tons (1000 kilograms) meters

4U.S.GOVERNMENT PRINTINGOFFICE:1974 582-414/82 1.)