# -~'~EPA-~';....... ".~ ....Unlt~d"States ~ '-"- " Ehwronmental Protectlon Agency EffluentGuldehnesDwlslon andPermitsDtwslon WashingtonDC20460 EPA-440/1-84/091g February1984 

# Guiclan~-Manual forEle~roplating andMetalFinishing PretreatmentStandards "%.,

2~2
- - g~a
~c:2o

5~

/

2

### GUIDANCEMANUAL FOR ELECYROPLATINGAND METALFINISHING PRETREATMENTSTAN[)ARDS
Preparedby The EffluentGuidelinesDivision officeofWaterRegulationsandStandards and PermitsDivision OfficeofWaterEnforcementandpermits

February1984

U.S. EnvironmentalProtectionAgency 401M StreetS.W. Washington,DC 20460

### UNITEDSTATESENVIRONMENTALPROTECTIONAGENCY WASHINGTON.D.C. 20460

OFFICEOF WATER



### MEMORANDUM 

### SUBJECT• FROM:

TO: Guidance Manual for Electroplating and Metal Finishing Pretreatment Standards Martha G. Prothro, Director_ C~~> Permits Division (EN-336) ~ ~ . ~- Jeffery D. Denit, Direct~i~- Effluent Guidelines Divis~6~('WH-552) Users of the Guidance Manual This manual provides information to assist Control Authorities and Approval Authorities in implementing the National Categorical Pretreatment Standards for the Electroplating and Metal Finishing Point Source Categories .(40CFR Parts 413 and 433, respectively). It is designed to supplement themore detailed documents listed as references in themanual; it is not designed to replace them. If you need more complete information on a specific item, you should refer to the appropriate reference. EPA developed this manual to fill several needs. First, it should be useful to Control Authorities in responding tomost routine inquiries from regulated manufacturers. More complex inquiries may require the use of the listed references. Second, Approval Authorities should find thismanual useful / in responding to specific category determination requests submitted by industries under the Electroplating and Metal FiniShing regulations. In addition, many integrated facilities have raised questions regarding the relationship between the Electroplating regulation and the Metal Finishing regulation and between the Metal Finishing regulation and other regulations listed in Section 433.10 of the Metal Finishing regulation. Themanual will provide information on responding to category determination requests and questions from integrated facilities. ........- 2 - 

### Finally, the manual addresses application of the combined wastestream formula to integrated facilities with regulated and unregulated wastestreams. It also provides current information on removal credits and the status of the fundamentally different factors variance provision in light of the recent court decision. It further explains how facilities subject to these regulations may use the certification procedure tominimize their sampling and analysis for total toxic organic pollutants. We hope that POTWs will find this manual to be a useful tool in implementing the Electroplating and Metal Finishing Categorical Pretreatment Standards. Itmay also be useful in implementing other categorical pretreatment standards. Please feel free to write to either the Office of Water Regulations and Standards (WH-551) or the Office of Water Enforcement and Permits (EN-336) with suggestions, additions, or improvements.

/,

### ACKNOWLEDGEMENTS
Wewishtoacknowledgetheconsiderableeffortsandcooperationof'the manypeoplewhose~contributionshelped inthesuccessfulcompletionof this document. ~~ Thisdocumentwas prepared underthedirectionofMr.MarvinRubin, officeofQuality.~Review,EffluentGuidelinesDivisionandDr.JanesGallup,~ NationalPretreatmentCoordinator. Mr.RichardKinchoftheEffluent GuidelinesDivision,andMessrs. TimothyDwyerandRobertF.Eagen, Jr. ofthe NationalPretreatmentProgramareto beacknowledgedfortheirvaluable input. Inaddition,membersof theOfficeofGeneralCounsel and other membersoftheEffluentGuidelinesDivisionandOfficeofWaterEnforcement andPermitsDivisionareacknowledged fortheirimportantc()ntributions. Thisdocument\waspreparedbyJRBAssociatesandWhitescarverAssociates, Inc. underEPAContractNo. 68-01-6514.TABLE OF CONTENTS

I. INTRODUCTION ................................................... i.I HISTORY OF THE ELECTROPLATING AND METAL FINISHING CATEGORICAL PRETREATMENT STANDARDS ........................ PAGE I-I
I-2
2. ELECTROPLATING CATEGORICAL PRETREATMENT STANDARDS .............. 2-I 2.1 AFFECTED INDUSTRY......................................... 2-I 2.2 EXCEPTIONS FROM REGULATION COVERAGE ....................... 2-3 2.3 PRETREATMENT STANDARDS FOR THE ELECTROPLATING CATEGORY.... 2-4 2.4 POLLUTANTS EXCLUDED FROM REGULATION....................... 2-7 2.5 COMPLIANCE DATES.......................................... 2-7
3. METAL FINISHING CATEGORICAL PRETREATMENT STANDARDS ............. 3-I 3.1 AFFECTED INDUSTRY......................................... 3-I 3.2 EXCEPTIONS FROM REGULATION COVERAGE ....................... 3-I 3.3 PRETREATMENT STANDARDS FOR METAL FINISHING CATEGORY....... 3-14 3.4 POLLUTANTS EXCLUDED FROM REGULATION....................... 3-16 3.5 COMPLIANCE DATES.......................................... 3-19 3.6 ALTERNATIVE CYANIDE LIMITATION............................ 3-19
4. TREATMENT TECHNOLOGIES ......................................... 4-I 4.1 TREATMENT OF COMMON METALS WASTES......................... 4-I 4.2 TREATMENT OF COMPLEXED METAL WASTES ....................... 4-3 4.3 TREATMENT OF PRECIOUS METALS WASTES....................... 4-3 4.4 TREATMENT OF HEXAVALENT C H R O M I U M . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4 4.5 TREATMENT OF CYANIDE WASTES ............................... 4-4 4.6 TREATMENT OF OILY WASTES.................................. ~ 4-5 4.7 IN-PLANT CONTROL OF TOXIC ORGANICS ........................ 4-5 

### 4.8 TREATMENT OF SLUDGES...................................... 4-6 4.9 IN-PROCESS CONTROL TECHNOLOGIES ........................... 4-6

. REQUIREMENTS OF THE GENERAL PRETREATMENT REGULATIONS ........... 5-i 5.1 INTRODUCTION .............................................. 5-I 5.2 CATEGORY DETERMINATION REQUEST............................ 5-2TABLE OF CONTENTS

5.3 MONITORING AND REPORTING REQUIREMENTS OF THE GENERAL PRETREATMENT REGULATIONS .................................. 5.3.1 Baseline Monitoring Reports........................ 5.3.2 Report on Compliance ............................... 5.3.3 Perlodlc Reports on Continued Compliance ........... 5.3.4 Notice of Slug Loading............................. 5.3.5 Monitoring and Analysis to Demonstrate Continued Compliance ............................... 5.3.6 Signatory Requirements for Industrial User Reports....................................... 5.3.7 Recordkeeping Requirements ......................... 5.4 SPECIAL INDUSTRIAL SELF-MoNITORING CONSIDERATIONS ......... 5.4.1 Toxic Organics Certification ....................... 5.4.2 Self-Monltorlng for Cyanide........................ 5.5 APPLICATION OF THE COMBINED WASTESTREAM FORMULA........... 5.6 REMOVAL CREDITS........................................... 5.7 FUNDAMENTALLY DIFFERENT FACTORS VARIANCE.................. 5.8 LOCAL LIMITS.............................................. PAGE
5-2 5-2 5-5 5-6 5-6 5-6 5-7 5-7 5-7 5-7 5-9 5-9 5-12 5-21 5-22

REFERENCES ......................................................... R-]LIST OF TABLES AND FIGURES

Table 1.1 2.1
2.2 3.1 3.2
3.3 3.4 3.5
5.1 5.2 5.3 5.4 Breakdown of the Electroplating/Metal Finishing Industry..... Pretreatment Standards for Existing Sources
- Electroplating Category...................................... Compliance Dates for Electroplating Pretreatment Standards... Metal Finishing Category Unit Operations..................... Potential Wastewater Pollutants Generated byMetal Finishing Category Unit Operations........................... Pretreatment Standards for the Metal Finishing Category...... Long Term Concentration Averages............................. Compliance Dates forMetal Finishing Pretreatment Standards.................................................... Due Dates for Submission of Baseline Monitoring Reports...... Combined Wastestream Formulas................................ Combined Wastestream Formula Example Calculation............. Combined Wastestream Formula Example Calculation.............

3.1 Schematic Showing Example of Overlap Coverage of Categorical Standards at Integrated Facilities............... 4.1 Wastewater Treatment Schematic............................... I-3
2-5 2-7 3-2
3-12 3-17 3-18
3-20 5-4 5-13 5-14 5-15

3-15 4-2i. INTRODUCTION

The National Pretreatment Program establishes an overall strategy for controlling the introduction of nondomestic wastes topublicly owned treatment works (POTWs) in accordance with the overall objectives of the Clean Water Act. Sections 307(b) and (c) of theAct authorize the Environmental ProtectionAgency todevelop national pretreatment standards for new and existing dischargers to POTWs. The Act made these pretreatment standards enforceable against dischargers to publicly owned treatment works.
The General Pretreatment Regulations (40 CFR Part 403) establish administrative mechanisms requiring nearly 1,700 POTWs to develop local pretreatment programs to enforce the general discharge prohibitions and specific Categorical Pretreatment Standards. These Categorical Pretreatment Standards are designed toprevent the discharge of pollutants which pass through, interferewith, or are otherwise incompatible with the operation of the POTWs. The standards are technology-based for removal of toxic pollutants and contain specific numerical limitations based on an evaluation of specific technologies for the particular industrial categories. As a result of a settlement agreement, the EPAwas required to develop Categorical Pretreatment Standards for 34 industrial categories with aprimary emphasis on 65 classes of toxic pollutants.
This manual will provide guidance to POTWs on the application and enforcement of the Categorical Pretreatment Standards for the Electroplating andMetal Finishing Categories. This document is based primarily on two sources: Federal Register notices, which include the official announcements' of the Categorical Standards, and the Final Development Documents for Electroplating andMetal Finishing, which provide a summary of the technical support for the regulations. Additional information on the regulations, manufacturing processes, and control technologies can be found in these sources. A listing of the references used in the development of this manual is provided at the end of this document.

I-I

### I.I HISTORY OFTHE ELECTROPLATINGANDMETAL FINISHING CATEGORICAL PRETREATMENT STANDARDS There are 13,500 plants in the electroplating/metal finishing industry. Many dischargewastewaters fromseveralmetal finishing operations other than, and in addition to, electroplating. Part 413 (electroplating) currently applies only to flows from the six specified electroplating processes. These Part 433 (metal finishing regulations) will apply to those electroplating streams and also towastestreams frommost othermetal finishing operations within the sameplants. The Part 433 PSESwill apply only toplants already coveredbyPart 413; however Part 433will often cover additionalwastewater within the sameplants. Thus the Part 433 limits ondischarge of toxic metals, toxic organics, and cyanidewill apply tomost faciiities in the electroplating/metal finishing industry.
The industry canbedivided into the sectors indicated onTable I.I. Facilities are either "captives" (thosewhich ina calendaryear ownmore than 50% [areabasis] of thematerials undergoingmetal finishing); or "job shops" (thosewhich ina calendar year donot ownmore than 50% [areabasis] ofmaterial undergoingmetal finishing). Captives canbe further divided by twodefinitions: "integrated" plants are thosewhich, prior to treatment, combine electroplatingwaste streams with significant processwaste streams not covered by the electroplating category; "non-lntegrated" facilities are thosewhichhave significant wastewater discharges only fromoperations addressed by the electroplating category. Many captives (50%) are "integrated" facilities. Whereas captives oftenhave a complex range of operations, job shops usually perform fewer operations. In theory job shops canbe divided like captives; inactuality, however, approximately 97% of all job shops in this industry are "non-integrated."
Pretreatment standards for the electroplatlng industrywere first established in 1974 but itwas not until promulgation of 40CFRPart 413 on September 7, 1979 that Electroplating Categorical Pretreatment Standards became areality. The 1979 Standards established specificnumerical limitations fordischargers fallingwithin seven subcategories. Shortly thereafter,



### I"--2

### Table I.I BREAKDOWNOFTHE ~ ~ ELECTROPLATING/METAL FINISHING INDUSTRY

(Numberofplantsper sector 13,470)

Jobshops] and IPCBM-

(3,470) Captive facilities (I0,000) Nonintegrated Integrated Indirect 3,061 job& 3,750non- 3,750 dischargers IPCBM indirect integrated integrated (10,561) captive captive Direct 409 job& dischargers IPCBM ~(2,909) directs (2) 

### (2)

1 

### Independent printed circuitboardmanufacturers. 2 2,500 captivedirects.

I-3petitions to review the electroplating pretreatment standards were filed in the Court ofAppeals by several industry groups. EPA reached a settlement agreement with the industry groups and agreed to adopt changes to the Standards which were promulgated onJanuary 28, 1981. The major changes incorporated by the 1981 amendments to the Electroplatlng Standards included: 

### I) 2) 3) 4) 5) Revision of the daily maximum limitation for total cyanide from 0.8 to 1.9mg/l Revision of 30-day average limits to 4-day average limits Adoption of the concept of integrated and non-integrated facilities Extension of compliance dates Recognition of the development of additional pretreatment standards to be called "Metal Finishing" which would regulate processes currently falling under electroplating as well asmany other metal finishing processes. However, EPA stated that in light of the potentially severe economlc impact of these anticipated regulations on the job shop (and independent printed circuit board) segment of the industry, theAgency would not impose more stringent pretreatment standards for that segment of the industry for several years.
In accordance with theAgency's plan, EPA promulgated theMetal Finishing Categorical Pretreatment Standards onJuly 15, 1983 as 40 CFR Part 433. The effect of the 1983Metal Finishing Standards was to create anew category - Metal Finishing

- which most electroplaters would have to comply with following their compliance with the Electroplating Standard. These subsequent limits would apply uniformly todischarges from electroplating and other metal finishing operations. This would meet industry's requests for equivalent limits for process lines often found together andwould greatly reduce the need for the combined wastestream formula (see Section 5.5). Once the compliance date for theMetal Finishing Standards is reached, all firms, conducting one ormore of the six basic operations of the Electroplatlng Category (see Section 2.1) must come into compliance with theMetal Finishing Pretreatment Standards, with the exception of existing job shop electroplaters and independent printed circuit board manufacturers. Existing indirect job shop electroplaters and independent printed circuit board manufacturers must still comply with the Part 413 Electroplatlng Pretreatment Standards and are exempt from the Part 433Metal Finishing Standards.

I-4fl 

### / 11 

### Non-integrated and integrated electroplaters must complywith Electroplating Pretreatment Standards forExisting/Sources (PSES) forMetals and Cyanide byApril 27, 1984; andJune~0~ 1984, respectively. All electroplaters must complywith theTotal Toxic Organics (TTO) PSES byno later than July 15, 1986 (SeeTable 2.2). Electroplaters subject to theMetal Finishing PSESmust complywith the Metals, Cyanide, and Final TTO PSES by no later thanFebruary 15, 1986 (See Table 3.5). After this date, theMetal Finishing PSES supercede theElectroplating PSES. With the exception ofplants covered by the Iron and Steel standards, electroplaters subject to theMetal Finishing PSES must complywith an interimTTO PSES byno later than June 30, 1984. Amore complete discussion of compliance dates ispresented in subsequent sections of this manual.

1-5

### 2. ELECTROPLATING CATEGORICAL PRETREATMENT STANDARDS (40CFR PART 413)

2.1 AFFECTED INDUSTRY TheElectroplatlng Standards are applicable towastewater fromany orall of these sixspecific operations (See theElectroplating Final Development Document).
i. Electroplating 2. Electroless Plating 3. Anodizing 4. Coatings 5. Chemical Etching andMilling 6. Printed Circuit BoardManufacturing
These sixelectroplating operations arebriefly discussed below:
I.

. Electr~plating is theproduction of a thin surface coating of on~ metalupon another by electrodeposition. Ferrous ornonferrous basis materials may be coatedby avariety of common (copper, nickel, lead, chromium, brass, bronze, zinc, tin, cadmium, iron, aluminumor combinations thereof) orprecious (gold, silver, platinum, osmium, iridium, palladium, rhodium, indium, ruthenium, or combinations thereof) metals. Inelectroplatlng, metal ions supplied by the dissolution ofmetal fromanodes or otherpieces, are reduced on the workpieces (cathodes)while ineither acid, alkaline, orneutral solutions. The eleetroplatlng baths containmetal salts, alkalies, and other bath control compounds inaddition toplatingmetals such as copper, nickel, silver or lead. Many plating solutions containmetallic, metallo-organic, and organic additives to induce grain refining, leveling of theplating surface, anddeposit brightening. Electroless Plating is the chemical deposition of ametal coating on aworkplece by immersion inanappropriate plating solution. Electricity isnot involved, therefore uniformdeposits are easily obtained. Copper andnickel electroless plating forprinted circuit boards are themost common operations. Inelectroless nickelplating the source ofnickel is a salt, andareducer isused toreduce the nickel to its base state. A complexlng agent isused tohold the metal ion in solution. Immersionplating, which forpurposes of this

2-I.

.

.

. regulation is considered part of electroless plating, produces a metal deposit by chemical displacement; however, it is not an autocatalytic process but is promoted by one of the products of the reaction. Immersion plating baths are usually formulations of metal salts, alkalies and complexing agents (typically cyanide orammonia). Anodizing is an electrochemical process which converts the metal surface to a coating of an insoluble oxide. Aluminum is the most frequently anodized material. The formation of the oxide occurs when the parts are made anodic in dilute sulfuric or chromic acid solutions. The oxide layer begins formation at the extreme outer surface, and as the reaction proceeds, the oxide grows into the metal. Chromic acid anodic coatings are more protective than sulfuric acid coatings and are used if a complete rinsing of the part cannot be achieved. Anodizing wastewater typically contains the basis material and either chromic or sulfuric acid. When dyeing of anodized coatings occurs, thewastewaters will contain chromium or other metals from the dye. Other potential pollutants include nickel acetate (used to seal anodic coatings) or other complexes andmetals from dyes and sealers. Coatings include chromating, phosphating, metal coloring and passivating. Pollutants associated with these processes enter the wastestream through rinsing and batch dumping of process baths. The process baths usually contain metal salts, acids, bases, and dissolved basis materials. In chromating, aportion of the base metal is converted to a component of the protective film formed by the coating solutions containing hexavalent chromium and active organic or inorganic compounds. Phosphate coatings are formed by the immersion of steel, iron, or zinc plated steel in a dilute solution of phosphoric acid plus other reagents to condition the surfaces for cold forming operations, prolong the life of organic coatings, provide good paint bonding and improve corrosion resistance. Metal coloring involves the chemical method of converting the metal surface into an oxide or similar metallic compound toproduce a decorative finish. A variety of solutions utilizing many metals may contribute to thewastestream. Passivating is the process of forming aprotective film onmetals by immersion in an acid solution, usually nitric acid ornitric acidwith sodium dichromate. Etching and Chemical Milling are processes used to produce specific design configurations or surface appearances onparts by controlled dissolution with chemical reagents or etchants. Chemical etching is the same process as chemical milling except the rates and depths of metal removal ere usually much greater in chemical milling. The majorwastestream constituents are the dissolved basis material and etching solutions. Printed Circuit BoardManufacturln~ involves the formation of a circuit pattern of conductive metal (usually copper) onnonconductive board materials such as plastic or glass. There are five basic steps

2-2

### involved in themanufacturing ofprinted circuit boards: cleaning and surface preparation, catalyst andelectroless plating, pattern printing andmasking, electroplating, and etching. Wastewater is produced in themanufacturing of printed circuit boards fromthe followingprocesses:

a. Surface preparation

- The rinses following scrubbing, alkaline cleaning, acid cleaning, etchback, catalyst application, and activation. b. Electroless plating

-Rinses following the electroless plating step.
c. Pattern plating

-Rinses following acid cleaning, alkaline cleaning, copperplating, and solderplating. d. Etching

-Rinses following etching and solder brightening.
e. Tabplating

-Rinses following solder stripping, scrubbing, acid cleaning, andnickel, gold, or otherplating operations. f. Immersion plating

-Rinses following acid cleaning and immersion tinplating. Additionally, watermay beused for subsidiary purposes suchas rinsing away spills, air scrubbingWater, equipmentwashing, and dumping spent process solutions. Theprincipal constituents of the wastestreams fromtheprinted circuit board industry are suspended solids, copper, fluorides, phosphorus, tin, palladium, and chelating agents. LowpHvalues are characteristic of thewastes because of thenecessary acid cleaning and surfacepretreatment. Inaddition to t~e above operations, theElectroplating Standards also J 

### apply to the related operations of alkaline cleaning, acidpickle, and strippingwhen each operation is followed by arinse.

2.2 EXCEPTIONS FROMREGULATION COVERAGE Operations similar to electroplatingwhich are specifically exempt from coverageunder theElectroplating Categorical Pretreatment Standards include:
I. Electrowinning and electroreflning conducted as part ofnonferrrous metal smelting and refining (40CFR Part 421);

2-32. Metal surface preparation and conversion coating conducted as part of coil coating (40 CFR Part 465); 3. Metal surface preparation and immersion plating or electroless plating conducted as a part of porcelain enameling (40 CFR Part 466);

.

.

.

. Electrodeposition of active electrode materials, electroimpregnation, and electroforming conducted as part of battery manufacturing (40 CFR Part 461); Metallic platemaking and gravure cylinder preparation conducted within printing and publishing facilities; and Continuous strip electroplating conducted within iron and steel manufacturing facilities. Surface treatment including anodizing and conversion coating conducted as part of aluminum forming (40 CFR Part 467).
2.3 PRETREATMENT STANDARDS FOR THE ELECTROPLATING CATEGORY Indirect dischargers that perform electroplating operations are currently subject to the Electroplating Categorical Pretreatment Standards (40 CFR Part 413). The Electroplating Standards were developed based on the best practicable control technology (BPT) and apply only to existing indirect sources (PSES). EPA established Pretreatment Standards on the basis of concentration with alternate mass-based standards for Electroplatlng. The production based standards are based onmilligrams per square meter of operation. Electroplating Standards are based on daily maximum and four day average value limits (with four day average value limits defined as the average value from four consecutive sampling days). The PSES limitations for electroplaters and the alternate mass-based standards are presented in Table 2.1. Note that the limitations and the pollutants regulated are different for dischargers of less than I0,000 gallons per day of regulated Electroplatlng process wastewater as compared to dischargers of I0,000 gallons per day ormore of regulated Electroplating process wastewater. Also, all new sources which perform electroplatlng operations are subject to theMetal Finishing regulations (40 CFR Part 433).

2-4

### TABLE 2.1 PRETREATMENT STANDARDS FOREXISTING SOURCES (PSES) ELECTROPLATING CATEGORY Facilities Dischargin~ <38,000 liters (1.2,000gallons) per day

Pollutant ," Cadmium (T) Lead (T) Cyanide, A Total Toxic Organics (TTO)1 DailyMaximum 1.2 0.6 5.0 4.57 

### Maximum 4DayAverage 

## (mgll) 0.7 0.4 2.7

m-- 

### Facilities Discharging >38,O00 liters (I0,000 gallons) perday

Pollutant DailyMaximum (mgll) Maximum 4DayAverage (mg/l) Cadmium (T) Chromium (T) Copper (T) Lead (T) Nickel (T) Zinc (T) Silver (T) 2 Total Metals3 Cyanide, T Total Toxic Organics (TTO)I 1.2 7.0 4.5 0.6 4.1 4.2 1.2 i0.5

1.9 2.13 0.7 4.0 2.7 0.4 2.6 2.6 0.7 6.8 1.0

Cyanide, A =Cyanide, amenable to chlorination Cyanide (T) =Cyanide, Total (T) =Total

INo regulation of themaximum 4-day average forTTO. 2The silver pretreatment standard applies only toprecious metals plating. 3Total metals is defined as the sumof the concentration of copper, nickel,

total chromium, and zinc.

2-5

### TABLE 2.1 (continued)
Alternate Mass-Based Limitations For Electroplating Subcategories Discharging 38,000 liters (I0,000 gallons) per day ormore

Pollutant DailyMaximum (mg/sqm of Operation) Electroplating, Electroless Plating, Chemical Etching andMilling, Coatings, Anodizing Maximum 4DayAverage (mg/sqm of O~eration) Electroplating, Electroless Plating, Printed Chemical Etching Printed Circuit andMilling, Circuit Board Coatings, Board Manufacturing Anodizing Manufacturing Cadmium (T) 47 107 29 65 Chromium, (T) 273 623 156 357 Copper (T) 176 401 105 241 Lead (T) 23 53 16 36 Nickel (T) 160 365 i00 229 Zinc (T) 64 374 102 232 Silver (T) 1 47
--- 29
--- Totalmetals2 410 935 267 609 Cyanide (T) 74 169 39 89 TTO
-Maximum for any one day is 2.13mg/l iThe silver pretreatment standard applies only toprecious metals plating. 2Totalmetals is defined as the sumof themasses of copper, nickel, total

chromium, and zinc.

2-62.4 POLLUTANTS EXCLUDED FROM REGULATION The EPA excluded from regulation 7 of the 126 toxic pollutants which are given priority consideration (antimony, arsenic, asbestos, beryllium, mercury, selenium, and ~hallium). These pollutants are found in only a small number of sources and are effectively controlled by the technologies onwhich the limits are based.
2.5 COMPLIANCE DATES The Agency divided the industry into two groups on the basis ofwastewater complexity:

a. Integrated facility - a facility which performs electroplating as only one of several operations necessary for manufacture of a product at a single physical location, which has significant quantities of process wastewater from nonelectroplating operation, and which, prior to or at the point of treatment (or proposed treatment), combines one ormore electroplating process water lines with one ormore plant sewers carrying process wastewater from non-electroplating manufacturing operations. b. Non-integrated

- any facility which is not integrated.
This division results in different compliance dates as shown in Table 2.2, below.

TABLE 2.2 COMPLIANCE DATES FOR ELECTROPLATING PRETREATMENT STANDARDS 40 CFR PART 413

Pollutant Parameter Existing Indirect Dischargers Compliance Dates Non-lntegrated Facilities Integrated Facilities
Metals and Cyanide Total Toxic Organics (TTO) April 27, 1984 July 15, 1986 June 30, 1984 July 15, 1986

2-7. METAL FINISHING CATEGORICAL PRETREATMENT STANDARDS (40 CFR PART 433)

3.1 AFFECTED INDUSTRY The Metal Finishing Category covers wastewater discharges from 46unit operations, the six operations previously addressed by the Electroplating regulation, plus an additional 40 operations. If any of the six electroplating operations are present, then theMetal Finishing pretreatment regulations apply towastewater from any of the 46 listed metal finishing operations. If a facility does not perform at least one of sixElectroplating operations, it is not subject to theMetal Finishing regulation. These metal finishing unit operations are summarized and described inTable 3.1. Table 3.2 summarizes thewastewaters potentially generated by each of themetal finishing unit operations. Since the Standards regulate processes and not industry groups, specific SIC codes do not determine coverage.
3.2 EXCEPTIONS FROM REGULATION COVERAGE Excluded from theMetal Finishing regulations are all existing indirect discharging job shop electroplaters, independent printed circuit board manufacturers, and any facility which does not perform at least one of the six basic Electroplating processes. Job shops are defined as those facilities which in a calendar year own 50% (area basis) or less of thematerial undergoing metal finishing. Independent Printed Circuit Board Manufacturers (IPCBMs) are defined as facilities which manufacture printed circuit boards principally for sale to other companies. These facilities remain subject only to the Electroplating (Part 413) Standards, primarily tominimize the economic impact to these relatively small facilities. Also excluded from theMetal Finishing regulations are those facilities which perform metallic platemaking and gravure cylinder preparation conducted within printing and publishing facilities.

3-i

### TABLE 3.1. METAL FINISHING CATEGORYUNIT OPERATIONS

Unit Operations SummaryDescription ofUnit Operations

Lo I 

### I. Electroplating

2. Electroless Plating

3. Anodizing

4. Coatings The production of a thin surface coating of onemetal upon anotherby electrodeposition. Ferrous ornonferrous basismaterialsmaybe coated by avariety of common (copper, nickel, lead, chromium, brass, bronze, zinc, tin, cadmium, iron, aluminum or combinations thereof) orprecious (gold, silver, platinum, osmium, iridium, palladium, rhodium, indium, ruthenium, or combinations thereof)metals. In electroplating, metal ions supplied by the dissolution ofmetal from anodes orother pieces, are reduced on thework pieces (cathodes) while in either acid, alkaline, orneutral solutions. The chemical deposition of ametal coating on aworkpieceby immersion in an appropriate plating solution inwhich electricity is not involved. Copper and nickel electroless plating for printed circuitboards are the most common operations. Immersion plating, which forpurposes of the Metal Finishing regulation is considered part of electroless plating, produces ametal deposit by chemical displacement. An electrochemical process which converts themetal surface to a coating of an insoluble oxide. Aluminum is themost frequently anodized material. The formation of the oxide occurs when theparts aremade anodic indilute sulfuric or chromic acid solutions. The oxide layer begins formation at the extreme outer surface, and as the reaction proceeds, the oxide grows into themetal. Any operation that includes chromating, phosphating, metal coloring and passivating. In chromating, aportion of thebasemetal is converted to a component of the protective film formed by the coating solutions containinghexavalent chromium and active organic or inorganic compounds. Phosphate coatings are formedby the immersion of steel, iron, or zinc plated steel in adilute solution ofphosphoric acid plus other reagents to condition the surfaces for further processing. Metal coloring involves the chemicalmethod of converting themetal surface into an

### TABLE 3.1. METAL FINISHING CATEGORYUNITOPERATIONS (Continued)

Unit Operations SummaryDescription of Unit Operations

Lo I Lo 

### 5. Etching and Chemical Milling

6. Printed Circuit Board Manufacturing

7. 

### Cleaning

8. 

### Machining

9. Grinding oxide or similarmetallic compound toproduce adecorative finish. Passivating is the process of forming aprotective filmonmetals by immersion inan acid solution, usually nitric acid ornitric acidwith sodiumdichromatel These operations are used toproduce specific design configurations or surface appearances onpartsby controlled dissolutionwith chemical reagents or etchants. Chemical etching is the same process as chemical" milling except the rates anddepths ofmetal removal are usuallymuch greater inchemicalmilling. This operation involves the formation of acircuit pattern of conductive metal (usually copper) onnonconductive boardmaterials such as plastic orglass. There are fivebasic steps involved in themanufacturing of printed circuit boards: cleaning and surface preparation, catalyst and electroless plating, patternprinting andmasking, electroplating, and etching. This operation involves theremoval of oil, grease, and dirt from the basismaterial usingwaterwith orwithout detergents or other dispersing agents. Acid cleaning is aprocess inwhich an acid isusedwith a wetting agent ordetergent toremove oil, grease, dirt, or oxide from the metal surface. This operation involves thegeneral process of removing stock froma workpiece by forcing a cutting tool through theworkpiece, thereby removing achip of basis material. Machining operations incorporate the use ofnatural and synthetic oils for cooling and lubrication. This operation involves the process of removing stock from aworkpiece by the use of a tool consisting of abrasive grains held by a rigid or semirigidbinder. Natural and synthetic oils are used for cooling and lubrication inmany grinding operations.

### TABLE 3.1. METAL FINISHING CATEGORYUNIT OPERATIONS (Continued)

Unit Operations SummaryDescription ofUnit Operations

I 

### I0. Polishing

Ii. Barrel Finishing (orTumbling)

12. Burnishing

13. Impact Deformation This abrading operation is used to remove or smooth out surface defects (scratches, pits, toolmarks, etc.) that adversely affect the appearance or function of apart. Area cleaning andwashdown canproducewastes that enterwastewater streams. Thewastes would belong to the common metals and oilywaste types. This operation is a controlledmethod ofprocessing parts to remove burrs, scale, flash, and oxides aswell as to improve surface finish. Barrel finishing produces auniformity of surface finish not possible by hand finishing and is generally themost economicalmethod of cleaning and surface conditioning. Wastewater isgenerated by rinsing ofparts following the finishing operation andbyperiodic dumping ofprocess solutions. Contributions to the commonmetals, hexavalent chromium, cyanide, and oilywaste types couldbemade by this operation, depending upon the chemical solutions employed. This operation involves the process of finish sizing or smooth finishing aworkpiece (previouslymachined or ground) bydisplacement, rather than removal, ofminute surface irregularities. Wastes may come from spills, leaks, process solution dumps and post-finish rinsing and could contribute to the commonmetals, preciousmetals, and oilywaste types depending upon thebasismaterial finished. In addition, sodium cyanide (NaCN)maybe used as awetting agent and rust inhibitor (for steel), thus contributing cyanidewastes from this o~eration. ,z 

### This operation involves the process of applying an impact force toa workpiece such that theworkpiece ispermanentlydeformed or shaped. Wastes containing conmlonmetals and oilywastesmay come from cleaning the parts or cleanup of leaks or spills.TABLE 3.1. METAL FINISHING CATEGORY UNIT OPERATIONS (Continued)

Unit Operations Summary Description of Unit Operations

kO ! k~ 14. Pressure Deformation

15. Shearing

16. Heat Treating

17. Thermal Cutting

18. WeIding This operation involves the process of applying force (at a slower rate than at impact force) to permanently deform or shape aworkpiece. Wastes containing common-metals and oily wastes may come from cleaning the parts or cleanup of leaks or spills. This operation involves the process of severing or cutting aworkpiece by forcing a sharp edge or opposed sharp edges into the workpiece stressing thematerial to the point of shear failure and separation. Wastes containing common metals and oily wastes may come from cleaning the~parts or cleanup of leaks or spills. This operation involves themodification of the physical properties of a workpiece through the application of controlled heating and cooling cycles. Wastewater is generated through rinses, bath discharges, spills, and leaks, and often contain the solution constitutents aswell as various scales, oxides, and oils. This operation involves the process of cutting, slotting or piercing a workpiece using an oxyacetylene oxygen lance or electric arc cutting tool. Water may be used for rinsing or cooling of parts and equipment following this operation. Wastewaters'produced would contribute to the common metals and oily waste types. This operation involves the process of joining two ormore pieces of material by applying heat, pressure or both, with or without filler material, to produce a localized union through fusion or recrystallization across the interface. This operation is followed by quenching, cooling or annealing in a solution ofwater or emulsified oils. When this is done, wastes produced can belong to the common metals waste type.

### TABLE 3.1. METAL FINISHING CATEGORY UNIT OPERATIONS (Continued)

Unit Operations Summary Description ofUnit Operations

t~J I C~ 

### 19. Brazing

20. Soldering

21. Flame Spraying

22. Sand Blasting This operation involves the process of joiningmetals by flowing a thin, capillary thickness layer ofnonferrous fillermetal into the space between them. Bonding results from the intimate contact produced by the dissolution of a small amount ofbasemetal in themolten fillermetal, without fusion of thebasemetal. The termbrazing is usedwhere the temperature exceeds 425°C (800°F). This operation is followed by quenching, cooling or annealing ina solution ofwater or emulsified oils. When this isdone, wastes produced canbelong to the commonmetals waste type. This operation involves the process of joiningmetals by flowing a thin (capillary thickness) layer of nonferrous fillermetal into the space between them. Bonding results from the intimate contact produced by the dissolution of a small amount ofbasemetal in themolten filler metal, without fusion of thebase metal. The term soldering isusedwhere the temperature range fallsbelow 425°F (800°F). This operation is followed by quenching, cooling or annealing in a solution ofwater or emulsified oils. When this isdone, wastes produced canbelong to the commonmetals waste type. This operation involves the process of applying ametallic coating toa workpiece using finelypowdered fragments ofwire, together with suitable fluxes, which are projected through a cone of flame onto theworkpiece. This operation is followedby quenching, cooling or annealing in a solution ofwater or emulsified oils. When this is done, wastes produced canbelong to the commonmetalswaste type. This operation involves the process of removing stock, including surface films, from aworkpiece by theuse of abrasive grains pneumatically impinged against theworkpiece.TABLE 3.1. METAL FINISHING CATEGORY UNIT OPERATIONS (Continued)

Unit Operations Summary Description of Unit Operations

~O I 23. Abrasive Jet Machining

24. Electrical Discharge Machining

25. Electrochemical Machining

26. Electron Beam Machining This operation is amechanical process for cutting hard brittle materials. It is similar to sand blastingbut uses much finer abrasives carried at high veioc'ities (500-3000 fps) by~a liquid or gas stream. Wastewater can be produced through solution dumps, spills, leaks or washdowns ofwork areas and contributes to the common metals and oily waste types. This operation is a process which can remove metal from anymetal with good dimensional control. Themachining action is caused by the formation of an electrical spark between an electrode, shaped to the required contour, and the workpiece. Rinsing ofmachined parts and work area cleanups can generate wastewaters which also contain base materials. These wastewaters contribute to the common metals and oily waste types. This operation is aprocess based on the same principles used in electroplating except the workpiece is the anode and the tool is the cathode. Electrolyte is pumped between the electrodes and a potential applied which results in removal of themetal. In addition to standard chemical formulations, inorganic and organic solvents are sometimes used as electrolytes for electrochemical machining andwith the basis material being machined, can enter waste steams via rinse discharges, bath dumps, and floor spills. Generated wastes can belong to the common metals, cyanide, and solvent waste types depending upon the solvent used. This operation is a thermoelectric process whereby heat is generated by high velocity electrons impinging on part of the workpiece. At the point where the energy of the electrons is focused, it is transformed into sufficient thermal energy to vaporize thematerial locally and is generally carried out in avacuum.

### TABLE 3.1. METAL FINISHING CATEGORY UNIT OPERATIONS (Continued)

Unit Operations SummaryDescription ofUnit Operations

I OO 

### 27. Laser BeamMachining

28. PlasmaArcMachining

29. Ultrasonic Machining

30. Sintering

31. Laminating

32. Hot Dip Coating This operation is the process whereby ahighly focusedmonochromatic collimated beamof light is used to removematerial at thepoint of impingement on aworkpiece. Laserbeammachining is a thermoelectric processwithmaterial removal largely accomplished by evaporation, although somematerial is removed in the liquid state athigh velocity. This operation is theprocess ofmaterial removal or shaping of a workpiece by ahighvelocity jet ofhigh temperature ionized gas. A gas (e.g., nitrogen, argon, orhydrogen) ispassed through anelectric arc causing it tobecome ionized and raised to temperatures in excess of 16,649°C (30,000°F). The relatively narrowplasma jetmelts and displaces theworkpiecematerial in its path. This operation is amechanical process designed to effectivelymachine hard, brittlematerials. It removesmaterial by theuse of abrasive grainswhich are carried in a liquidbetween the tool and thework, and which bombard thework surface athighvelocity. This operation is the process of forming amechanical part from a powderedmetal by fusing the particles together under pressure andheat. The temperature ismaintained below themelting point of the basismetal. This operation is the process of adhesive bonding layers ofmetal, plastic, orwood to form apart. Water isnot oftenused in this operation; however, occasional rinsing or coolingmay occur in conjunctionwith laminating. Thewaste generated could contribute to the common metals and oilywaste types. This operation is the process of coating ametallic workpiece with anothermetal toprovide a protective filmby immersion in amolten bath. Galvanizing (hot dip zinc) is themost commonhot dip coating. Water is used for rinses following precleaning and sometimes forquenching after coating. Thesewastewaters can contribute to the commonmetals waste type.TABLE 3.1. METAL FINISHING CATEGORY UNIT OPERATIONS (Continued)

Unit Operations Summary Description of Unit Operations

L~ I kO 33. Sputtering

34. Vapor Plating

35. Thermal Infusion

36. Salt Bath Descaling

37. Solvent Degreasing This operation is the process of covering ametallic or non-metallic workpiece with thin films ofmetal. The surface tobe coated is bombarded with positive ions in a gas discharge tube, which is evacuated to a low pressure. This operation is the process of decomposition of ametal or compound upon aheated surface by reduction or decomposition of avolatile compound at a temperature below themelting point of either the deposit or the basis material. This operation is the process of applying a fused zinc, cadmium, or other metal coating to a ferrous workpiece by inbuing the surface of the workpiece with metal powder or dust in the presence ofheat. This operation is the process of removing surface oxides or scale from a workpiece by immersion of the workpiece in amolten salt bath or ahot salt solution. Molten salt baths are used to remove oxides from stainless steels and other corrosion-resistant alloys. These baths contain molten salts, caustic soda, sodium hydride and chemical additives. These contaminants (and a small amount of base material and oils) enter wastewater streams through rinsing, spills, leaks, batch dumps of process solutions, and improper handling of sludge produced by the process. Wastewaters produced by salt bath descaling contribute to the common metals and oily waste types. This operation is a process for removing oils and grease from the surface of aworkpiece by the use of organic solvents such as aliphatic petroleums, aromatics, oxygenated hydrocarbons, halogenated hydrocarbons, and combinations of these classes of solvents. These pollutants can enter wastewater streams and contribute to the toxic organic waste type.

### TABLE 3.1. METAL FINISHING CATEGORYUNIT OPERATIONS (Continued)

Unit Operations SummaryDescription ofUnit Operations

L~ I O 

### 38. Paint Stripping

39. Painting
40. Electrostatic Painting

41. Electropainting

42. VacuumMetalizing

43. Assembly This operation is the process of removing anorganic coating from a workpiece. The stripping of such coatings isusuallyperformed with caustic, acid, solvent, ormolten salt. The strippingwastes can contain any of the constituents of the paint being removed, aswell as a small amount of thebasismaterial beneath the paint and the constitutents of the stripping solution. Wastes are primarily generated by rinsing and can also contain small amounts of emulsified oils. Wastes produced belong to the common metals and oilywaste types andmay contain toxic organics. This operation is the process of applying an organic coating to a workpiece. This operation involves the application of electrostatically charged paint particles to anoppositely charged workpiece followed by thermal fusing of the paint particles to forma cohesive paint film. This operation is the process of coating aworkpiece by eithermaking it anodic or cathodic in abath that isgenerally an aqueous emulsion of the coatingmaterial. Electropainting is used primarily forprimer coats because it giyes a fairly thick, highly uniform, corrosion resistant coating inrelatively little time. Ultrafiltration isused in connection with electropainting to concentrate paint solids. Wastewaters from these unit operations can contribute to the commonmetals, hexavalent chromium, and solvent waste types. This operation is the process of coating aworkpiecewithmetal by flash heatingmetal vapor in ahigh-vacuum chamber containing theworkpiece. Thevapor condenses on all exposed surfaces. This operation involves the fitting together ofpreviouslymanufactured parts or components into acomplete machine, unit ofamachine, or structure.TABLE 3.1. METAL FINISHING CATEGORY UNIT OPERATIONS (Continued)

Unit Operations Summary Description of Unit Operations

LO 44. Calibration

45. Testing

46. Mechanical Plating This operation involves the application of thermal, electrical, or mechanical energy to set or establish reference points for a component or complete assembly.; This operation involves the application of thermal, electrical, or mechanical energy to determine the suitability or functionality of a component or complete assembly. Leak testing, final washing (automobiles, etc.), and test area washdowns enter wastestreams and may contain oils and fluids used at testing stations aswell as heavy metal contamination derived from the component being tested. These wastewaters can contribute to the commonmetals and oily waste types. This operation is the process of depositing metal coatings on aworkpiece via the use of a tumbling barrel, metal powder, and usually glass beads for the impaction media. The operation is subject to the same cleaning and rinsing operations that are applied before and after the electroplating operation.
Note: Unit Operations 1 through 6 are considered to be core operations. If a facility does not perform at least one of these six electroplating operations, it is not subject to theMetal Finishing regulation.

### TABLE 3.2 POTENTIALWASTEWATERPOLLUTANTSGENERATEDBYMETALFINISHING UNITOPERATIONS

Unit Operations Hexavalent Metals Chromium Cyanide Oils Toxic Organics Zero 

### Discharge

LO I ~O Io 

### 2. 3. 4. 5. 6. 7. 8. 9. I0. II. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. Electroplating Electroless Plating Anodizing ConversionCoating Etching (ChemicalMilling) PrintedCircuitBoardManufacturing Cleaning Machining Grinding Polishing BarrelFinishing (Tumbling) Burnishing ImpactDeformation PressureDeformation Shearing HeatTreating ThermalCutting Welding Brazing Soldering FlameSpraying SandBlasting OtherAbrasiveJetMachining ElectricDischargeMachining Electrochemical Machining ElectronBeamMachining LaserBeamMachining PlasmaArcMachining X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X :(

X X

X X

X

X X X X X X X X X X X

X X X X X X X X

X X XTABLE 3.2 POTENTIALWASTEWATER POLLUTANTS GENERATEDBYMETAL FINISHING UNITOPERATIONS



### Unit Operations Hexavalent Metals Chromium Cyanide Oils Toxic Organics Zero Discharge

Lo I LO 

### 29. UltrasonicMachining 30. Sintering 31. Laminating 32. HotDipCoating 33. Sputtering 34. VaporPlating 35. Thermal Infusion 36. SaltBathDescaling 37. SolventDegreasing 38. Paint Stripping 39. Painting 40. ElectrostaticPainting 41. Electropainting 42. VacuumMetalizing 43. Assembly 44. Calibration 45. Testing 46. MechanicalPlating X X

X X X Y. X X
X

X X

X X X X

X X X X X X

X X X

X

XIn certain cases, another Categorical Pretreatment Standard may also cover wastewater discharges frommetal finishing operations. In these situations, the more specific standards will apply to those metal finishing wastestreams which appear to be covered by both standards. The following regulations take precedence over the Metal Finishing regulation.

- Nonferrous Smelting and Refining (40 CFR Part 421)

- Coil Coating (40 CFR Part 465)

- Porcelain Enameling (40 CFR Part 466)

- Battery Manufacturing (40 CFR Part 461)

- Iron and Steel Manufacturing (40 CFR Part 420)

- Metal Casting Foundries (40 CFR Part 464)

- Aluminum Forming (40 CFR Part 467)

- Copper Forming (40 CFR Part 468)

- Plastic Molding and Forming (40 CFR Part 463)

- Electrical and Electronic Components (40 CFR Part 469)

- Nonferrous Forming (40 CFR Part 471)
For example, if a plant performs a cleaning and phosphate coating operation~in preparation for painting and also performs cleaning, pickling, immersion coating, and chemical coating as part of aporcelain enameling process, then the Metal Finishing PSES apply to the discharge from the cleaning and phosphate coating operation, while the Porcelain Enameling PSES apply to the discharge from applicatlon of the porcelain enamel and also the preparatory operations of cleaning, pickling, immersion plating, and chemical coating operation. Normally, the metal preparation operations (cleaning, pickling, immersion plating, and chemical coating) would be subject to the Metal Finishing regulation. However, because the Porcelain Enameling regulations specifically include those operations performed in preparation for the porcelain enameling operation, the Porcelain Enameling regulation takes precedence for those wastestreams (See Figure 3.1).
3.3 PRETREATMENT STANDARDS FOR THE METAL FINISHING CATEGORY The Metal Finishing Standards (40 CFR Part 433) establish pretreatment standards for new and existing facilities performing electroplating and other

3-14

# l, 

# I I I I I I I 

# L_Metal Finishing Process

| Metal Finishing

- cleaning

- phosphate coating

Metal Finishing

- painting 

# I I 

# I 

# I I I I I I 

# I J [ Porcelain Enameling

Metal Preparation i

- cleaningi

- pickling

- immersionplating1 1

- chemical coating

Porcelain Enameling

- steel coating 

# ®2

A.B2 Wastewater to Discharge These four operatlons are normally subject to theMetal Finlshing regulation; however, in this case, they are performed immediately prior to a porcelain enameling operation. These types of operations were included aspart of the database used to develop the Porcelain Enameling regulations, thus, in this situation, they are subject to the Porcelain Enameling regulation. Wastestream ~is subject to Part 433 if discharged. Wastestream ~ is subject to Part 466 if discharged. If thewastestreams are combined before discharge, the combined discharge (A+B) is subject to the combinedwastestream formula.

FIGURE 3.1 SCHEMATIC SHOWING EXAMPLE OF OVERLAP COVERAGE OF CATEGORICAL STANDARDSAT INTEGRATED FACILITIES

3-15metal finishing operations. These standards are BAT-equivalent and represent the best available technology economically achievable. All existing indirect discharging electroplating facilities (except job shop electroplaters and IPCBMs) must first comply with the Electroplating (Part 413) and thenwith the Metal Finishing (Part 433) regulations. Another exception is continuous strip electroplating at Iron and Steel Mills which is subject only to the Metal Finishing regulation; this unit operation isnot subject to the Electroplating regulation. The limits apply uniformly to discharges from all electroplating and other metal finishing operations. The uniformity in standards meets industry requests for equivalent limits for process lines often found together. The Metal Finishing Standards also reduce the need touse the Combined Wastestream Formula. No production based standards were developed for theMetal Finishing (Part 433) Regulation. The Metal Finishing standards are based on the 99th percentile of expected variations from observed long-term unconstructed averages. They include daily maximums and maximum monthly (statistically based on 10 samples permonth) average concentration limitations. The PSES and PSNS limitations for metal finishing facilities are presented in Table 3.3. If aplant intends to consistently comply with the regulatory limit it should use the long term concentration average as the basis for design and operation. Table 3.4 presents long-term concentration averages which were found to be attainable by the technology EPA assessed. They are presented as guidance to dischargers and control authorities.
The pretreatment standards for new sources (PSNS) apply to electroplating and metal finishing facilities which began their operation after August 31, 1982, the date of the proposed regulation. The PSNS for metal finishing facilities are the same as those for existing sources, with the exception that cadmium must be controlled more stringently.
3.4 POLLUTANTS EXCLUDED FROM REGULATION The EPA excluded from regulation 7 of the 126 toxic pollutants which are given priority consideration (antimony, arsenic, asbestos, beryllium, mercury, selenium, and thallium). These pollutants are found in only a small number of sources and are effectively controlled by the technologies onwhich the limits are based.

3-16TABLE 3.3 PRETREATMENT STANDARDS FOR THE METAL FINISHING CATEGORY 40 CFR PART 433

PRETREATMENT STANDARDS FOR EXISTING SOURCES (PSES) Daily Maximum Monthly Pollutant Maximum (mg/l) Average (mg/l) Cadimium (T) 0.69 0.26 Chromium (T) 2.77 1.71 Copper (T) 3.38 2.07 Lead (T) 0.69 0.43 Nickel (T) 3.98 2.38 Silver (T) 0.43 0.24 Zinc (T) 2.61 1.48 Cyanide, total 1.20 0.65 Total Toxic Organics (interim) 4.57
-- Total Toxic Organics (final) 2.13
-- Alternative to total cyanide: Cyanide, amenable to chlorination 0.86 0.32

PRETREATMENT STANDARDS FOR NEW SOURCES (PSNS) Daily Maximum Monthly Pollutant Maximum (mg/l) Average (mg/l) Cadmium (T) 0.II 0.07 Chromium (T) 2.77 1.71 Copper (T) 3.38 2.07 Lead (T) 0.69 0.43 Nickel (T) 3.98 2.38 Silver (T) 0.43 0.24 Zinc (T) 2.61 1.48 Cyanide, total 1.20 0.65 Total Toxic Organics 2.13
-- Alternative to total cyanide: Cyanide, amenable to chlorination 0.86 0.32
Note: No maximum monthly average TTO concentration regulated. (T) = total.

3-17

### TABLE 3.4 LONG TERMCONCENTRATION AVERAGES

Pollutant of Pollutant Property Long Term Concentration Average Milligrams

PerLiter

(mg/l) Cadmium (T)I Chromium (T) Copper (T) Lead (T) Nickel (T) Silver OT) Zinc (T) Cyanide (T) Cyanide, A TTO (rawwater) TTO (effluent) 0.13 0.572 0.815 0.20 0.942 0.096 0.549 0.18 0.06 1.08 0.434
ICadmium (T) fornew sources is 0.058mg/l.

3-183.5 COMPLIANCE DATES All industries subject to the Electroplating Standards (except job shop electroplaters and IPCBMs) will have to comply with the~Metal Finishing (Part 433) regulations. The control of toxic organics is an additional requirement for facilities currently under Electroplating PSES. Compliance was found to be achievable with good management practices (recovering solvents for contract hauling or reclamation) and at low costs. An interim TTO limit based solely on achieving compliance with good housekeeping practices before end-of-pipe treatment is required to be in-place, and was established toprevent organics from being completely uncontrolled during the time before final compliance. The Metal Finishing compliance dates are shown inTable 3.5.
3.6 ALTERNATIVE CYANIDE LIMITATION An alternative cyanide limit is available for facilities with significant forms of complexed cyanide (i.e. iron cyanides) not controllable by the technology basis. These complexed forms are less toxic but may still undergo transformation to the more toxic free cyanide form in thewaterways. Before allowing the cyanide amenable alternative, the Control Authority should consider possible water quality impacts due to the discharge of cyanide. Complex cyanides can be controlled by the addition of ferrous sulfate to the precipitation/clarification system.

3-19

### TABLE 3.5 COMPLIANCE DATES FORMETAL FINISHING PRETREATMENT STANDARDS 40CFR PART 433
Pollutant Parameter Interim TTO1 Metals, Cyanide, and Final TTOExisting Sources New Capitives Sources June 30, 19842 February 15, 1986 on commencement ofdischarge
ITTO =Total Toxic Organics 2july I0, 1985 forplants covered by 40 CFR Part 420, Iron and Steel

3-204. TREATMENT TECHNOLOGIES
The treatment technologies described in this section are currently used bymetal finishers/electroplaters to remove or recoverwastewater pollutants normally generated. Figure 4.1 is an example of the current technology commonly used for treatment ofmetal finishingwastewater. As indicated, wastestream segregation allows the recovery of precious metals, the reduction of hexavalent chromium, the destruction of cyanide, and the removal and recovery of oils prior to the removal of commonmetals. Wastestream segregation can reduce the flow ofwastewater to the treatment system and, accordingly, reduce the cost of treatment.
4.1 TREATMENT OF COMMON METALS WASTE The technology basis for the pretreatment standards consists of hydroxide precipitation followed by sedimentation. Hydroxide precipitation is used to precipitate dissolvedmetals by chemical addition so that they can be removed by physical means such as sedimentation or filtration. Hexavalent chromium is not removed by this treatment system and cyanidewill interferewith the system's ability to remove the dissolved metals. These rawwaste types should be treated before entering this system.
The EPA also considered but rejected the addition of filtration to the selected technology basis to remove additional suspended solids .(such as metal hydroxides) which did not settle out in the clarifier. It may be appropriate in cases where there are specific ambient water quality problems. The tech~ nology basis treatment systemplus in-plant cadmium controls (such as evaporative recovery and ion exchange) was used as the technology basis for new source pretreatment standards.
Alternative treatment methods for commonmetals removal, to be used in conjunctionwith or inplace of thepreceeding methods, include peat adsorption, insoluble starch xanthate filtration, sulfide precipitation, flotation, andmembrane filtration.

4-I.,t'- I I'0 | 

### L'~mnl~lm ; I i le~m~ ~ I rrec,ouw | | -- -*
.... I CClq) I 

### i , I ! Metals . I MetalI | I I Osstructtonl : ! Reuov.] I I ~ I 

### I ' 

# L

. . . . . . 

# J IL - .__..J L_.,._._.J i I 

# T ~,~-! : 

# ~ 1 

# / ,Ig / ; ,

_ - / I / . ...l.d o.

-- -- WithoutCyanide I~¢lalmad 

# I: ........ '_L___L ....... f WasteDIscharqe (11~latmentSystem Influent) t 

### "-- i- ........ 1
L
...... J /
......

## /

~ Ibst.e 

### (Ck~mnI~tals) r-..... -I 

### i mtali . 

# L._-~_':J F ~tod

! PinslIYeatad 

### Effluent 

### ! I I 

# t t~auled

### Or I~claimd

FIGURE 4.1 WASTEWATER TREATMENT SCHEMATIC ~o~mal

### l~ute

..... OptionalItoute Mote~Diacharqe [Ntampreciousmetalst~owty mybe hauled inalternative ~m~,depmdlng(;nthe recoverymethodIntree.4.2 TREATMENT OF COMPLEXED METAL WASTES Complexed metals are tied up by chemicals (complexing agents such as ammonia and citric acid) which prevent the metals from settling out of solution. Complexed metal wastes are aproduct of electroless plating, immersion plating, etching and printed circuit board manufacturing. Metals tied up in solution counteract the conventional precipitation technique. As a result, segregated treatment of the complexed metal wastes is recommended. High pH precipitation is aprocess involving the addition of chemicals which drastically increase the pH to around 12, prompting a shift in the complex dissociation equilibrium and resulting in the production of free metal q ions. The metal ions can then be precipitated by available hydroxide ions and removed by sedimentation.
The chemical reduction process adds chemicals to lower the pH of the wastestream (to break up the various metal complexes) followed by the addition of a reducing agent to reduce the metals to an oxidation state which permits precipitation of the metals. Additional chemicals to raise the pH are then added to formmetallic precipitates which settle out of solution. Media or membrane filtration is an alternate method to sedimentation for solids removal. Modifying the hydroxide precipitation process by substituting sulfide precipitation can improve systemperformance in the removal of complexed heavy metals. The ferrous sulfate technique is capable of achieving lowmetal solubilities in spite of the presence of certain complexing agents.
4.3 TREATMENT OF PRECIOUS METALS WASTES Treatment of precious metals consists of the technology basis for common metals wastes plus precious metals recovery including evaporation, ion exchange, and electrolytic recovery. Evaporation is used to recover precious metals by boiling off the water portion of the precious metal solution and removing themetal.

4-3lon exchange is the process inwhich ions, held by electrostatic forces to charged functional groups on the surface of an ion exchange resin, are exchanged for ions of similar charge from the solution inwhich the resin is immersed. Ion exchange is commonly used for precious metal recovery, especially gold. Electrolytic recovery is particularly applicable to precious metals recovery because the valuable precious metals offer a faster payback on equipment and energy costs. The process consists of a dragout rinse after the plating step and an off line electrolytic recovery tank.
4.4 TREATMENT OF HEXAVALENT CHROMIUM The treatment of hexavalent chromium involves reducing hexavalent chromium to trivalent chromium and removal with a conventional precipitationsolids removal system. Reduced (trivalent) chromium is able to be separated from solution in conjunction with other metallic salts by alkaline precipitation. Inmost cases, gaseous sulfur dioxide is used as the reducing agent in the reduction of hexavalent chromiumwhich enables the trivalent chromium to be separated from solution by alkaline precipitation.
Alternative hexavalent chromium treatment techniques include electrochemical chromium reduction, regeneration, evaporation, and ion exchange.
4.5 TREATMENT OF CYANIDE WASTES Treatment of cyanide is almost exclusively performed by alkaline chlorination which focuses upon oxidizing the cyanide which is amenable to chlorination. The destruction of cyanide results inproducts of carbon dioxide and nitrogen. Additionally, ferrous sulfate may be used to precipitate complexed cyanides.
Alternative treatment techniques for the destruction of cyanide include oxidation by ozone, ozone with ultraviolet radiation, hydrogen peroxide, and electrolytic oxidation.

4-44.6 TREATMENT OF OILY WASTES Techniques commonly used by electrolaters andmetal finishers to remove oils include skimming, coalescing, emulsion breaking, flotation, centrifugation, ultrafiltration, and reverse osmosis. Treatment of oilywastes is most efficient and cost effective if oils are segregated from other wastes and treated separately. The process of separation varies depending on the type of oil involved.
4.7 IN-PLANT CONTROL OF TOXIC ORGANICS The primary control technology for toxic organics is proper storage of concentrated toxic organics without discharging directly into wastestreams and segregation from other wastes that will enter thewaste treatment system. Spent degreasing solvents may be segregated from other wastes by providing and identifying the necessary storage containers, training personnel in the use of the techniques, and holding periodic check-ups to ensure that proper segregation is occurring. The separate waste solvents can then be recovered on-site or contract hauled. Using cleaning techniques that require no solvents will eliminate or reduce the quantity of toxic organics found inwastewater. Cleaning techniques may include wiping, immersion, spray techniques using water, alkaline and acid mixtures, and solvent emulsions.
Toxic organics that enter the wastestreams can be removed by treatment technologies used for the control of other pollutants. Toxic organics tend to bemore soluble in oil and grease than inwater. Thus removal of oil and grease will reduce the discharge of toxic organics. Other possible mechanisms for removal include adsorption, settling, and volatilization, which can occur during treatment ofmetals, cyanide, and oil and grease. Specific treatment technologies which are not part of the technology basis of the regulation but are applicable for the treatment of TTO include carbon adsorption and reverse osmosis, resin adsorption, ozonation, chemical oxidation, and aerobic decomposition.

4-54.8 TREATMENT OF SLUDGES Sludges are created bywaste treatment technologies which remove solids fromwastewater. Sludge thickening is used to concentrate dilute sludges by a mechanical device such as a vacuum filter or centrifuge. Doubling the solids content reduces capital and operating costs and reduces costs for hauling. Pressure filtration is achieved by pumping the liquid through a filter materialwhich is impenetrable to the solid phase. Sludge bed drying is employed to reduce thewater content of sludges so that they can bemechanically collected for removal. Sludge may then be transported to landfills or incinerated.
Additional removal methods for industrial waste sludges include chemical containment, encapsulation, fixation, and thermal conversion.
4.9 IN-PROCESS CONTROL TECHNOLOGIES In-process control techniques have been developed and are being utilized by electroplaters and metal finishers. These techniques deal with reducing water usage, reducing drag out of pollutants and efficient handling of process wastes and include:

- Flow reduction through efficient rinsing

- Countercurrent and static rinsing

- Process bath conservation

- Waste oil segregation

- Process bath segregation

- Process modification

- Cutting fluid cleaning

- Integrated waste treatment

- Good housekeeping Reducing thewater usage at metal finishing facilities is the most important control and results in reduced pollutant discharge and consequently reduced costs forwastewater treatment. It is estimated that rinse steps consume most of the water used atmetal finishing facilities. Therefore, efficient rinse systems would lead to the greatest water use reductions. Several rinsing techniques are currently used at metal finishing facilities.

4-6Of these, the countercurrent rinse provides for themost efficient water usage, and consists of only one freshwater feed introduced in the last tank. The dead or static rinse is applicable for initial rinsing after metal plating and allows for easier metals recovery and lowerwater usage.

4-75. REQUIREMENTS OF THE GENERAL PRETREATMENT REGULATIONS
5.1 INTRODUCTION This section provides abrief overview of the General Pretreatment Regulations and identifies those provisions of the Regulations which have a direct bearing on the application and enforcement of Categorical Pretreatment Standards for the Electroplating andMetal Finishing category.
The General Pretreatment Regulations for Existing and New Sources (40 CFR Part 403) establish the framework and responsibilities for implementation of theNational Pretreatment Program. The effect of 40 CFR Part 403 is essentially three-fold. First, theGeneral Pretreatment Regulations establish general and specific discharge prohibitions as required by Sections 307(b) and (c) of the Clean Water Act. The general and specific prohibitions are described in Section 403.5 of the Pretreatment Regulations and apply to all nondomestic sources introducing pollutants into a POTWwhether or not the source is subject to Categorical Pretreatment Standards. Second, the General Pretreatment Regulations establish an administrative mechanism to ensure that National Pretreatment Standards (Prohibited Discharge Standards and Categorical Pretreatment Standards) are applied and enforced upon industrial users. Approximately 1,700 POTWs are required to develop a locally run pretreatment program to ensure that non-domestic users comply with applicable pretreatment standards and requirements. Third, andmost importantly for the purposes of this guidance manual, the General Pretreatment Regulations contain provisions relating directly to the implementation and enforcement of the Categorical Pretreatment Standards. Reporting requirements, local limits, monitoring or sampling requirements, and category determination provisions are discussed. POTW representatives should refer to 40 CFR Part 403 for specific language and requirements where appropriate.

5-i5.2 CATEGORY DETERMINATION REQUEST An existing industrial user (IU) or its POTW may request written certification from EPA or the delegated State specifying whether or not the industrial user falls within aparticular industry category or subcategory and is subject to a categorical pretreatment standard. Although the deadline for submitting a category determination request byexisting industrial users subject to the electroplating andmetal finishing categorical pretreatment standards has passed, a new industrial user or its POTW may request this certification for a category determination anytime ~ to commencing its discharge. The contents of a category determination request and procedures for review are presented in Section 403.6(a) of the General Pretreatment Regulations.
5.3 MONITORING AND REPORTING REQUIREMENTS OF THE GENERAL PRETREATMENT REGULATIONS In addition to the requirements contained in the Electroplating andMetal Finishing Categorical Pretreatment Standards, industrial users subject to these Standards must fulfill the reporting requirements contained in Section 403.12 of the General Pretreatment Regulations. These requirements include the submission of baseline monitoring reports, compliance schedules, compliance reports (initial and periodic), notices of slug loading, and recordkeeping requirements. Each of these reporting requirements is briefly summarized below.
5.3.1 Baseline Monitoring Reports All industrial users subject to Categorical Pretreatment Standards must submit a baseline monitoring report (BMR) to the Control Authority. The purpose of the BMR is to provide information to the Control Authority to document the industrial user's current compliance status with a Categorical Pretreatment Standard. The Control Authority is defined as the POTW if it has an approved pretreatment program, otherwise the BMRwill be submitted to the State (if the State has an approved State Pretreatment Program) or to the EPA Region. Additional guidance onBMR reporting is available from the EPA Regional Pretreatment Coordinator.

5-2BMR Due Dates Section 403.12(b) requires that BMRs be submitted to the Control Authority within 180 days after the effective date of a Categorical Pretreatment Standard or 180 days after the final administrative decision made upon a category determination request [403.6(a)(4)], whichever is later. Table 5.1 shows the respective due dates for electroplating andmetal finishing BMRs.
BMR Content A BMRmust contain the following information as required by Section 403.12(b).

.

.

.

.

. Name and address of the facility, including names of operator(s) and owner(s). List of all environmental control permits held by or for the facility. Brief description of the nature, average production rate and SICcode for each of the operation(s) conducted, including a schematic process diagramwhich indicates points of discharge from the regulated processes to the POTW. Flowmeasurement information for regulated process streams discharged to themunicipal system. Flowmeasurements of other wastestreams will be necessary if application of the combined wastestream formula is necessary. Identification of the pretreatment standards applicable to each regulated process and results of measurements of pollutant concentrations and/or mass. All samples must be representative of daily operations and results reported must include values for daily maximum and average concentration (ormass, where required). Where the flow of the regulated stream being sampled is less than or equal to 250,000 gallons per day, the industrial user must take three samples within a twoweek period. Where the flow of the stream is greater than 250,000 gallons per day, the industrial user must take six samples within a twoweek period. If samples cannot be taken immediately downstream from the regulated process and other wastewaters are mixed with the regulated process, the industrial user should measure flows and concentrations of the otherwastestreams sufficient to allow use of the combined wastestream formula. Requirements for demonstrating compliance with TTO standards are discussed in Section 5.4.1.

5-3

### TABLE 5.1 DUEDATES FOR SUBMISSION OF BASELINE MONITORING REPORTS Existing Indirect Dischargers Non-integrated

Job Shops & IPCBM's Integrated Job Shops

IPCBM's Non-integrated Captives Integrated Captives Electroplating

(Part 413) Metals and Cyanide Electroplating

(Part 413) TTO September 12, 1981
February 24, 1984 June 25, 1983
February 24, 198~ September 12, 1981 June 25, 1983

Metal Finishing

(Part 433) Metals, Cyanide, and TTO February 24, 1984 February 24, 1984

Note: If a request for a category determination has beenmade, then the BMR isdue 180days after the final decision on the category determination.

5-46. Statement of certification concerning compliance ornoncompliance with the Pretreatment Standards.

. If not in compliance, a compliance schedule must be submitted with the BMR that describes the actions the userwill take and a timetable for completing those actions to achieve compliance with the standard. This compliance schedule must contain specific increments of progress in the form of dates for the commencement and completion ofmajor events, however, no increment of the schedule shall exceed 9months. Within 14 days of each completion date in the schedule, the industrial user shall submit aprogress report to the Control Authority indicating whether ornot it complied with the increment of progress to bemet on such date, and, if not, the date onwhich it expects to complywith this increment of progress and the steps being taken to return to the schedule.

BMRReporting of Toxic Organics Since promulgation of theMetal Finishing pretreatment standards, some questions have been raised regarding BMR reporting of total toxic organics (TTO). BMR sampling requirements clearly apply to all regulated metals. However, since monitoring for toxic organics can be expensive, BMR sampling and analysis for TTOwill only be required for those organics "which would reasonably be expected to be present" in the industrial user's effluent [Section 413.03(c)]. For routine compliance monitoring, not BMRmonitoring, the regulations allow for the IU to certify that the regulated toxic organics are not used at the facility or to present aplan demonstrating appropriate controis to prevent organic compounds from entering thewastestream. Even if the industrial user expects to use the certification procedure to demonstrate regular compliance with the TTO limitation, the user must still sample and analyze for any toxic organic "reasonably expected to be present" for the purposes of the baseline monitoring report. If no toxic organics are used or expected to be discharged, then no TTOmonitoring is required for the BMR.
5.3.2 Report onCompliance Within 90 days after the compliance date for the Electroplating andMetal Finishing Pretreatment Standards or in the case of aNew Source following commencement of the introduction ofwastewater into the POTW, any industrial user subject to the Standards must submit to the Control Authority a "report on compliance" that states whether or not applicable pretreatment standards

5-5are being met on a consistent basis. The report must indicate the nature and concentration of all regulated pollutants in the facility's regulated process wastestreams; the average and maximum daily flows of the regulated streams; and a statement ofwhether compliance is consistently being achieved, and if not, what additional operation and maintenance and/or pretreatment is neces- sary to achieve compliance. See 40 CFR 403.12(d).
5.3.3 Periodic Reports on Continued Compliance Unless required more frequently by the Control Authority, all industrial users subject to the Electroplating andMetal Finishing Categorical Pretreatment Standards must submit a biannual "periodic compliance report" during the months of June and December. The report shall indicate the precise nature and concentrations of the regulated pollutants in its discharge to the POTW, the average and maximum daily flow rates of the facility, the methods used by the indirect discharger to sample and analyze the data, and a certification that these methods conformed to those methods outlined in the regulations. See 40 CFR 403.12(e). 5.3,4 Notice of Slug Loading Section 403.12(f) requires industrial users tonotify the POTW immediately of any slug loading of any pollutant, including oxygen demanding pollutants (BOD, etc.) released to the POTW system at a flow rate and/or pollutant concentration which will cause interference with the POTW.
5.3.5 Monitoring andAnalysis toDemonstrate Continued Compliance Section 403.12(g) states that the frequency ofmonitoring to demonstrate continued compliance shall be prescribed in the applicable Pretreatment Standard. Neither the Electroplating nor Metal Finishing Pret~eatment Standard establish anymonitoring frequency. Therefore, the appropriate Control Authority must establish the monitoring frequency to adequately demonstrate that indirect dischargers subject to these pretreatment standards are in compliance with the applicable standards. Unless otherwise noted in the appropriate paragraph of Section 403.12, themonitoring frequency established by the Control Authority shall be used in the baseline monitoring report (403.12(b)(5)),

5-6the report on compliance with categorical pretreatment standard deadline (403.12(d)), and the periodic reports on continued comPliance (403.12(e)). Sampling and analysis shall be in accordance with the procedures established in 40 CFR Part 136 and any amendments to it or shall be approved by EPA. When Part 136 techniques are not available or are inappropriate for any pollutant, then sampling and analysis shall be conducted in accordance with procedures established by the POTW orusing any validated procedure. However, all procedures for sampling and analysis not included in Part 136 must be approved by EPA.
5.3.6 Signatory Requirements for Industrial User Reports All reports submitted by industrial users (BMR, Initial Report on Compliance, and Periodic Reports, etc.) must be signed by an authorized representative in accordance with Section 403.12(k).
5.3.7 Recordkeeping Requirements Any industrial user subject to the reporting requirements of the General Pretreatment Regulations shall maintain records of all information resulting from anymonitoring activities required by 403.12 for aminimum of three years [403.12(n)]. These records shall be available for inspection and copying by the Control Authority.
5.4 SPECIAL INDUSTRIAL SELF-MONITORING CONSIDERATIONS 5.4.1 Toxic Organics Certification In lieu of monitoring for TTO, the Control Authority may allow dischargers subject to Electroplating andMetal Finishing regulations to certify that no dumping of toxic organics to thewastestream has occurred. In cases where monitoring to determine TTO compliance is necessary, sampling and analysis for TTOwill only be required for those organics "which would reasonably be expected to be present" in the industrial user's effluent [Section 413.03(c)]. When dischargers request that nomonitoring be required, they must submit a toxic organic management plan that specifies the toxic organic compounds used, themethod of disposal used (instead of dumping into

5--7wastestreams), and procedures for assuring that toxic organics do not routinely spill or leak intowastewater discharged to the POTW. This certification is added as a comment to the baseline monitoring report aswell as periodic reports.

A toxic management plan provides methods for the reduction of toxies in effluents and assists industrial facilities in achieving compliance with Categorical Pretreatment Standards. An example of a toxic organicmanagement plan that is requiredwhen industrial users wish to certify that no discharge of toxic pollutants has occurred is presented below.
The planhas three basic steps: Step 1 - Process engineering analysis should consist of:
a. An examination of published reports on the specific industry; b. A water flow diagram to identify all possiblewastewater sources; c. A list of rawmaterials used in the industrial processes, including chemical additives, water treatment chemicals and cleaning agents, and thewastewater stream that eachmaterial potentially enters; d. Comparison of the toxics found in the effluent with the list of raw materials and selection of themost probable wastewater source;
e. Evaluation of the toxics found in the effluent, but not on the raw materials list and determination of those formed as reaction products or by-products; f. Examination of sources such as equipment corrosion or rawmaterials impurities contributing inorganic pollutants.
Step 2 - Pollutant control evaluation should be determined on a case-bycase basis andmay include:

a. Inplant process modification, including chemical substitution, partial or complete recycling, reuse, neutralization, ion exchange, or operation changes.

5-8Step 3 - Toxics reduction evaluation report is submitted to the Control Authority and contains:

a. Identification of source(s) of pollutant(s). b. Control options explored.
c. Effectiveness of control options inmeeting effluent limits. d. Industrial user's choice of options and the projected schedule for achieving necessary control.

In certain cases, the industrial user will not achieve compliance with the effluent standard. In these cases, additional evaluations will be necessary.
5.4.2 Self-Monitoring for Cyanide For facilities subject toMetal Finishing regulations, self-monitoring for cyanide must he conducted after cyanide treatment and before dilution with other wastestreams. Alternatively, samples may be taken of the final effluent if the plant limitations are adjusted based on the dilution ratio of the cyanide wastestream flow to the effluent flow.
5.5 APPLICATION OF THE COMBINED WASTESTREAM FORMULA One provision of the General Pretreatment Regulations that will often be necessary for POTWs and industries to properly monitor and report on compliance with Categorical Pretreatment Standards is the Combined Wastestream Formula (CWF) [40CFR 403.6(e)]. The CWF is amechanism for calculating appropriate limitations specified in applicable regulations to awastewater in which process wastestreams are mixed with regulated, unregulated or dilution streams, thereby resulting in amixed effluent. The CWF is applied to the mixed effluent to account for the presence of the additional wastestreams.
The following definitions and conditions are important to the proper use of the CWF.

5-9Definitions

• Regulated Process Wastestream - an industrial process wastestream regulated by National Categorical Pretreatment Standards.

• Unregulated Process Wastestream - an industrial process wastestream that is not regulated by a categorical standard. Note: Definitions apply to individual pollutants. A wastestream from a process may be "regulated" for one pollutant and "unregulated" for another. Dilute Wastestream - Boiler blowdown, sanitary wastewater, noncontact cooling water or blowdown, and Paragraph 8 excluded wastestreams containing none of the regulated pollutant or only trace amounts of it.

• Concentration-based Limit - a limit based on the relative strength of a pollutant in awastestream, usually expressed inmg/l (ib/gal). Mass-based Limit - a limitation based on the actual quantity of a pollutant in awastestream, usually expressed inmg/some unit of production for a given operation such as square meter (ib/square foot per operation).
CWF Conditions To ensure proper application of the CWF, the following conditions must be met by amunicipality and its industries [40 CFR 403.6(e)]:
Alternative discharge limits that are calculated in place of a Categorical Pretreatment Standard must be enforceable as Categorical Standards. Calculation of alternative limits must be performed by the Control Authority (POTW) or by the industrial user with written permission from the POTW. Alternative limits must be established for all regulated pollutants in each of tbe regulated processes. The Control Authority and/or the industrial user may use mass-based limitations in place of the concentration-based limitations, when they are provided for by a given Categorical Pretreatment Standard such as electroplating, as long as aprior agreement exists between the regulated industrial user and the municipality that is receiving these wastes. Both daily maximum and long-term average (usually monthly) alternative limits must be calculated for each regulated pollutant.

5-10If process changes at an industry warrant, the Control Authority may recalculate the alternative limits at its discretion or at the request of the industrial user. The new alternative limits must be calculated and become effective within 30 days of the process change. The Control Authority may impose stricter alternative limits, but may not impose alternative limits that are less stringent than the calculated limits. A calculated alternative limit cannot be used if it is below the analytical detection limit for that pollutant. If a calculated limit is below the detection limit, the IUmust either: i) not combine the dilute streams before they reach the combined treatment facility, or 2) segregate allwastestreams entirely. The categorical standards of the regulated wastestreams which are applied to the CWF must be consistent in terms of the number of samples the standard is based on. Electroplating wastestreams are regulated by a-4-day average standard and are not consistent with other categorical standards regulated by amaximum monthly average (based on i0 sample days) standard. According to 40 CFR Part 413.04, if a non-electroplating wastestream is regulated by amonthly average standard and is combined with an electroplating wastestream, monthly standards rather than 4-day average standards are to be used in calculating an alternative limit with the CWF. Also, if two electroplating wastestreams regulated under different subcategories of the electroplating regulations are combined, the 4-day limits may be used to calculate the alternate limits, unless an additional wastestream subject tomonthly standards is added. The following equivalent monthly averages (based on i0 sample days per month) have been developed for use in the CWF:

Pollutant Equivalent Monthly Average (m~/l) Cadmium (T) 0.63 Chromium (T) 3.56 Copper (T) 2.44 Lead (T) 0.37 Nickel (T) 2.38 Zinc (T) 2.37 Silver (T) 0.63 Total Metals 6.26 Cyanide, A 2.37 Cyanide (T) 0.87

5-11Monitoring Requirements For Industrial Users Using the CWF Self-monitoring requirements by an industrial user are necessary to ensure compliance with the alternative categorical limit. Because neither the Metal Finishing nor Electroplating Pretreatment Standards include selfmonitoring requirements, the Control Authority will establish minimum selfmonitoring requirements. ARplicatlon of the CWF The actual combined wastestream formulas are presented inTable 5.2. Tables 5.3 and 5.4 present an example of how the CWF is used to calculate alternative limits and four example calculations applied to specific electroplating/metal finishing situations. Three of the examples differ because of the individual compliance deadlines for the different categorical pretreatment standards. The fourth example represents an example showing conversion from a production (mass) based standard to a concentration based standard. It is important to remember that when two or more regulated wastestreams are mixed prior to treatment, before using the CWF it is necessary to determine which pretreatment regulation applies to each regulated wastestream before they are mixed.
5.6 REMOVAL CREDITS A removal credit allows a POTW to provide categorical industrial users of its systemwith a credit (in the form of adjusted categorical pretreatment standards) for removal of pollutants by the POTW. Industrial users receiving such a credit are allowed to discharge to the POTW greater quantities of regulated pollutants than otherwise permitted by applicable categorical standards. Whether or not to seek authority to grant removal credits is completely at the discretion of the POTW. Section 403.7 of the General Pretreatment Regulations establishes the conditions under which a POTW would obtain approval togrant removal credits and specifies themeans bywhich these removal credits are to be determined.

In 1977, Congress amended section 307(b) of the CleanWater Act to provide for removal credits. EPA originally implemented that provision and established the conditions under which POTWs could obtain authorization to
5-12TABLE 5.2 COMBINED WASTESTREAM FORMULAS
Alternative Concentration Limit Formula:

Ct 

# i illciFiI IFtFd i : Fl x Ft

C - alternative concentration limit for the pollutant

t C i - Categorical Pretreatment Standard concentration limit for the pollutant in regulated stream i F. - average daily flow (at least 30 day average) of regulated stream i

i F d - average daily flow (at least 30 day average) of dilute wastestream(s) F t - average daily flow (at least 30 day average) through the combined treatment facility (including regulated, unregulated and dilute wastestreams) N - total number of regulated streams
Alternate Mass Limit Formula

X 

# I t-Fd 1

- i=l F i
M t - alternative mass limit for the pollutant M i - Categorical Pretreatment Standard mass limit for the pollutant in regulated stream i F i - average daily flow (at least 30 day average) of regulated stream i F d - average daily flow (at least 30 day average) of dilute wastestream(s) Ft - average daily flow (at least 30 day average) through the combined treatment facility (including regulated, unregulated and dilute wastestreams) N - total number of regulated streams.
5-13

### TABLE 5.3 COMBINED WASTESTREAM FORMULA EXAMPLE CALCULATION
The following examples provide the calculations fordetermining alternat discharge limits using the combinedwastestream formula. The examples assume combinations of various industries with the followingwastestreams:

Industrial Daily Max.

Category Wastestream Flow ZnLimit (Subcategory) Type (mgd) (mg/l) 2 Electroplating Regulated 0.4 4.2

(CommonMetals) Compliance Date June 30, 1984
Metal Finishing Regulated

(Electroplating)1 (Coating and Painting)1 Porcelain Enameling (Steel-coating only) Regulated 0.4 2.61 0.I 2.61 0.075 1.333 February 15, 1986
November 25, 1985 Copper Forming Regulated 0.4 Mass/Produc- August 15, 1986 tionBased4 Sanitary Waste Dilution 0.05 N/A N/A iThese are not subcategories; they aremetal finishing processes. 2Alternate production based limit = 164mg/m2plated. 3Alternate Mass/Production based limits = 53.3mg/m2forpreparation and 0.85

mg/m2 for coating. 4Mass/Production based limits = 0.943mg/off-kg of copper heat treated for solution heat treatment.
The calculated alternate discharge limits (Zn )in the following examples cwf are based onphased compliance dates forElectroplating, Porcelain Enameling, andMetal Finishing.

5-14

### TABLE 5.4 COMBINEDWASTESTREAMFORMULA EXAMPLECALCULATION
EXAMPLEA Alternativedischarge limit forintegratedelectroplater/porcelain enameler fromJune 30, 1984 (compliancedate forelectroplating) until November 25, 1985 (compliancedate forporcelainenameling). E1ectroplating I IMetalFinishing (CommonMetals)I I(C°ating&Painting)
Q =0.4mgd Zn= 4.2mg/l Q = 0.1mgd Zn=N/A Q =0.075mgd Zn=N/A Porcelain I Enameling (Steel)}ISwn~ttary I .

# l Q =0.05mgdI Zn N/A 

# J

Zn

### cwf (4.2mg/lx0.4m~d)X (0.4mgd+ 0.1mgd+0.075mgd+0.05mgd
- 0.05mgd) 0.4 mgd 0.625mgd

Zn =3.86mg/l cwf

Note: Duetodilutionfromsanitarywaste, theapplicableZnlimit, 4.2mg/l, isreduced to 3.86mg/l.

5-15

### TABLE 5.4 (Continued) COMBINEDWASTESTREAMFORMULA EXAMPLECALCULATION EXAMPLEB Alternative discharge limit for integrated electroplater/porcelain enameler fromNovember 25, 1985until February 15, 1986 (compliancedate for metal finishing) Electroplating I I Metal Finishing I (CommonMetals)[l(Coating&Painting)I Porcelain Enameling (Steel) Sanitary Waste
Q =0.4mgd Zn =4.2mg/1



### Zncwf I Q = 0.Imgd Q =0.075mgd Zn =N/A Zn= 1.33mg/l 

# 1
4.2

## mg/1(0.4 ~gd) + 1.33mg/1 (0.075 mgd) X (0.4 mgd+0.075 mgd) Q = 0.05mgd Zn=N/A

(0.4mgd+ 0.Imgd + 0.075mgd + 0.05mgd
- 0.05mgd) 0.625mgd

Zncwf = 3.45mg/l
Note: Alternate discharge limit isbased onElectroplatlng andPorcelain Enameling categorical standards andproportioned by the flowof the regulated electroplatlng andporcelain enameling wastestreams. Due to dilution fromsanitarywaste, thealternate discharge limit is reduced.

5-16

### TABLE 5.4 (Continued) COMBINEDWASTESTREAMFORMULA EXAMPLE CALCULATION EXAMPLEC Alternative discharge limit for integrated electroplater/porcelain enamelerafter February 15, 1986 (compliance date formetal finishing).
IMetalFinishingI Metal Finishing I (ElectropiatingI (Coating & Painting)l, CommonMetals) ~ Q = 0.4mgd Zn = 2.61 mg/l

Zncwf Porcelain Enameling (Steel)
Q = 0.imgd Q = 0.075mgd Zn = 2.61 mg/1 Zn = 1.33mg/l

2.61mg/l (0.5mgd) + 1.33m$/l (0.075m~d)X (0.5mgd+ 0.075mgd) Sanitary Waste
Q =0.05mgd Zn=N/A

(0.5m~d + 0.075 m$d+ 0.05m~d
- 0.05 mgd) 0.625mgd

°



### Zncwf = 2.25mg/l

Note: Electroplating (commonmetals) isnow coveredbyMetalFinishing, and is subject toaZn limit of 2.61mg/1. Thus, the alternate discharge limit isbased onMetal FinishingandPorcelainEnameling categorical standards andproportioned by the flowof the three regulatedwastestreams. Due todilution fromsanitarywaste, thealternate discharge limit isreduced to 2.25mg/1.

5-17

### TABLE 5.4 (Continued) COMBINED WASTESTREAM FORMULA EXAMPLE CALCULATION EXAMPLE D Copper Forming and several other categorical standards are expressed as production-based limits. The example below converts production-based limits to equivalent concentration-based limits. These equivalent concentrationbased limits can then beused as the standard for Copper Forming. Copper Forming (Solution Heat Treatment) = 0.943 mg/off-kg of copper heat Maximum Daily Limit for Zinc treated Average Daily Production During Last 12months = 30,000 off-kg of copper heat treated per day Average Daily Water Usage in Solution Heating Treating During Last 12months 400,000 gpd
Step i: Convert Production-based Limit toEquivalent Concentration Limit Concentration Equivalent (Production-Based Limit)(Avg. Daily Production Rate) (Avg. Daily Flow fromRegulated Process) (Conversion Factor) 0.943mg/off-kg (30~000 off-kg/day) = 0.019 mg/l Zn(equivalent) 400,000 gpd (3.785 liters/gallon) Step 2: Once the concentration-based equivalent is determined, then the alternate limit canbe calculated as inExample A. 

# I letaiFinishing naelingP°rcelain pSaltry Copper(solutionFOrmingHeat (Coating &Painting)[ (Steel) Treatment) Q = 0.4mgd I Q = 0.i mgd I Q = 0.075 mgd 1 Q = 0.05mgd Zn = 0.019 mg/l Zn = 2.61 Zn = 1.33 Zn =N/A (0.019mg/l x 0.4mgd) + (2.61mg/l x 0.I mgd) + (1.33mg/l x 0.075 mgd) Zn = cwf (0.4mgd + 0.1 mgd + 0.075 mgd) X (0.4mgd + 0.Imgd + 0.075 mgd + 0.05mgd
- 0.05 mgd) 0.625 mgd Zn = 0.59mg/l cwf Note: Off-kg shall mean themass of copper ore copper alloy removed from a forming or ancillary operation at the end of aprocess cycle for transfer toa different machine orprocess.

5-18TABLE 5.4 (Continued) COMBINED WAS.TESTREAM FORMULA EXAMPLE CALCULATION EXAMPLE E
For the several categorical standards shown in Example D, permit authorities may wish to utilize mass limits. The example below converts concentration limits £omass-based limits and utilizes the production-based limits (and alternate limits). Copper Forming Copper Forming (Solution Heat Treatment) = 0.943 mg/off-kg of copper heat Maximum Daily Limit for Zinc treated Average Daily Production During Last 12months = 30,000 off-kg of copper heat treated per day Average Daily Water Usage in Solution Heat Treating During Last 12months Allowable ZnMass = 0.993 (30,000) = 400,000 gpd

= 28,290 mg Metal Finishing Metal Finishing Maximum Daily Limit for Zinc = 2.61 mg/l Average Daily Production During Last 12months = not required Average Daily Water Usage in Metal Finishing = 100,000 gpd
Allowable Zn Mass = 2.61 (100,000 x 3.78)= 986,580 mg Porcelain Enameling Porcelain Enameling (steel basis material) = (53.3 + 0.85) mg/m2 of area Maximum Daily Limit for Zinc processed or coated thru metal preparation and coating operation, respectively. Average Daily Production During = 5570 m 2 of preparation Last 12months 7250 m 2 of coating

5-19

### TABLE 5.4 (Continued) COMBINED WASTESTREAM FORMULA EXAMPLE CALCULATION EXAMPLE E (Continued) Average Daily Water Usage in Porcelain Enameling Allowable ZnMass = 75,000 gpd

= 53.3(5570)+0.85(7250)=303,044 mg

Zn

### cwf

Zn

### cwf Copper Forming (Solution Heat

Treatment) 

# LI Metal Finishing (Coating &Painting) 

# I J Porcelain Enameling (Steel) Sanitary Waste

= 28,290 + 986,580 + 303,044

= 1,317,914 mg/day

= 1.3kg/day or (2.86 ibs/day)

5-20grant removal credits in the June 26, 1978 General Pretreatment Regulations. On January 28, 1981, the removal credits provision, as well as many other portions of the pretreatment regulations, were amended. Under the 1981 provision, any POTW seeking removal credit authority was required to demonstrate its removal performance by sampling its influent and effluent and calculating its removal rates based on this data. Removal capability of each POTW, therefore, was to be determined on a case-by-case basis. In addition to the sampling requirements the provision specified the other prerequisites for obtaining removal credit authority. Only theApproval Authority (either EPA or the State) can grant removal credit authority to a POTW.
A revised removal credit regulation was proposed on September 28, 1982 (47 Fed. Reg. 42698). The final regulation on removal credits is due for promulgation inMarch 1984. Until then, POTWs may apply for removal credit authority under the existing procedures contained in Section 403.7 of the January 28, 1981 General Pretreatment Regulations.
5.7 FUNDAMENTALLY DIFFERENT FACTORS VARIANCE A request for a fundamentally different factors (FDF) variance is a mechanism bywhich a Categorical Pretreatment Standard may be adjusted, making it more or less stringent, on a case-by-case basis. If an indirect discharger, a POTW, or any interested person believes that the factors relating to a specific indirect discharger are fundamentally different from those factors considered during development of the relevant categorical pretreatment standard and that the existence of those factors justifies a different discharge limit from that specified in the Categorical Standard, then they may submit a request to EPA for such avariance (See 40 CFR 403.13).
This section was the subject of a recent court decision (U.S. Court of Appeals for the Third Circuit) in September of 1983. The Court held that the EPA lacks authority to issue variances to indirect dischargers for toxic pollutants. As a result of the Court's decision, FDF variances can only be granted for non-toxic pollutants. Since the electroplating and metal finishing categorical standards contain limits only for toxics, no variance is available for this industry.

5-215.8 LOCAL LIMITS Local limits are numerical pollutant concentration ormass-based values that are developed by a POTW for controlling the discharge of conventional, non-conventional or toxic pollutants from indirect sources. They differ from National Categorical Pretreatment Standards in that Categorical Pretreatment Standards are developed by EPA and are based upon the demonstrated performance of available pollutant control technologies (for specific categorical industries). These national technology-based categorical standards do not consider local environmental criteria or conditions, and are only developed to assure that each industry within a specified category meets aminimum discharge standard which is consistent across the United States for all POTWs. Local limits, on the other hand, are developed to address specific localized impacts on POTWs and their receiving waters. Local limitations are typically designed to protect the POTW from:
The introduction of pollutants into the POTWwhich could interfere with its operation Pass-through of inadequately treated pollutants which could violate a POTW's NPDES permit or applicable water quality standards The contamination of a POTW's sludge which would limit sludge uses or disposal practices.
Local limits, as the'name implies, take into consideration the factors that are unique to a specific POTW, whereas categorical pretreatment standards are developed only for a general class of industrial dischargers. Local limits are required under 40 CFR 603.5 and must be developed when it is determined that Categorical Pretreatment Standards are not sufficient to enable the POTW tomeet the above three Pretreatment Program objectives.

To assist municipalities in developing defensible and technically sound numerical effluent limitations, EPA has prepared some general guidelines on limit development in its document "Guidance Manual for POTW Pretreatment Program Development." Appendix L of this document lists the general methodology, required formulas and typical environmental criteria used to develop local limits. This manual is available from EPA Regional offices and NPDES

5-22States and should be carefully followed when developing local limits. Although a detailed discussion of local limit development is beyond the scope of this document, the general methodology includes the following four steps: Step i - Determine the maximum headworks loading (for each specific pollutant) that will assure that the three fundamental objectives of the pretreatment program are met. Step 2 - Calculate the allowable loadlng to the POTW by subtracting the uncontrollable portion of pollutant discharge to the POTW (from domestic, commercial and infiltration/inflow sources) from the total headwork loading value. Step 3 - Distribute the controllable loading to industrial users through an allocation process. Step 4 - Derive specific local limits from the allocation results.
The above four step process must be performed for each pollutant which the POTW determines may need a specific local limitation. As a general rule, the limit setting analysis should be performed for all pollutants which are discharged to the POTW in significant quantities. The POTW should identify pollutants of concern through an evaluation of the POTW's industrial waste survey. A procedure for evaluating industrial waste survey results is included in the EPA guidance manual mentioned earlier.
To assist POTWs with the development of local limits EPA has developed a computer program that incorporates the general methodology required to develop local limits and ,alleviates a substantial amount of the tedious calculations , required to develop these limits. This computer program has the following capabilities to aid the POTW~in limit development:

• Performs the four-step limit setting analysis onmicrocomputer or mainframe

• 

### Screens input data 

### providedbythe POTW Supplements POTW datawith "built-in" files containing data on 

## Industrial~Municipal wastewater characteristics, POTW removal rates, and POTW inhibition values

5-23Allocates controllable pollutant loads using several different methodologies

• Compares calculated local limits to EPA Categorical Standards.

POTWs may obtain information on this computer program by contacting any of the ten EPA Regional offices. Instructions will be provided on how to use the computer program as well as how to access a computer system which supports it.

5-24

### REFERENCES

Electroplating FinalRegulations Promulgated CorrectionNotice (Typographical errors) CorrectionNotice (Delayed compliance for Integrated Facilities) Revision to 9/07/79Promulgation of 7/03/80 Amended (IntegratedFacilities Compliance) Amended (Added total toxicorganic limit) Amended (AllowsPSES compliancebeyond 7/1/84) Correction/ClarificationNotice (Compliance Dates) FederalRegisterNotice 09/07/79 44FR52618 10/01/79 44FR56330 03/25/80 45FR19246 01/28/81 40CFR9462 01/21/83 48FR2774 07/25/83 48FR32482 09/15/83 48FR41410 09/26/83 48FR43680
Metal Finishing Final Regulations Promulgated Amended (AllowsPSESCompliancebeyond 7/I/84 Correction/ClarificationNotice (ComplianceDates) CorrectionNotice (Typographical Errors) 07/15/83 48FR32485 09/15/83 48FR41410 09/26/83 48FR43681 10/03/83 48FR45105
General Pretreatment Regulations 40CFRPart 403, 46FR 9404 

### 01/28/81
FinalDevelopment Document - Electroplating FinalDevelopment Document - Metal Finishing August 1979
June 1983 440/1
- 79/003 440/1
- 83/091 GuidanceManual forPOTW Pretreatment ProgramDevelopment ProceduresManual forReviewing aPOTWPretreatment Program Submission October 1983 October 1983

Copies of the technical and economicdocumentsmaybe obtained fromthe NationalTechnical Information Services, Springfield, VA. 22161 (703/487-4650). Pretreament ProgramManualsmaybe obtained fromU.S. EPA, PermitsDivision (EN-336),Washington, D.C. 20460

R-1Unded States EnwronmentalProtection Agency WashmgtonDC20460 OfficialBusiness PenaltyforPrivateUse $300 SDec=al Fourth-Class Rate Book