-~'~EPA 

-~'; ....... ".~ .... Unlt~d"States ~ '-" - " 

Ehwronmental Protectlon 

Agency 

Effluent Guldehnes Dwlslon 

and Permits Dtwslon 

Washington DC 20460 

EPA-440/1-84/091 g 

February 1984 

Guiclan~-Manual 

for Ele~roplating 

and Metal Finishing 

Pretreatment Standards 

"%., 

2~2 - -

g~a 

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5~ 

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2 
GUIDANCE MANUAL 

FOR 

ELECYROPLATING AND METAL FINISHING 

PRETREATMENT STAN[)ARDS 

Prepared by 

The 

Effluent Guidelines Division 

office of Water Regulations and Standards 

and 

Permits Division 

Office of Water Enforcement and permits 

February 1984 

U.S. Environmental Protection Agency 

401M Street S.W. 

Washington, DC 20460 
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON. D.C. 20460 

OFFICE OF 

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 .(40 CFR Parts 413 and 433, respectively). 

It is designed to supplement the more detailed documents listed 

as references in the manual; 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 to most 

routine inquiries from regulated manufacturers. More complex 

inquiries may require the use of the listed references. 

Second, Approval Authorities should find this manual 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. The manual 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 to minimize 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. It may 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 

We wish to acknowledge the considerable efforts and cooperation of'the 

many people whose~ contributions helped in the successful completion of this 

document. ~~ 

This document was prepared under the direction of Mr. Marvin Rubin, 

office of Qua lity.~Review, Effluent Guidelines Division and Dr. Janes Gallup, ~ 

National Pretreatment Coordinator. Mr. Richard Kinch of the Effluent Guidelines Division, and Messrs. Timothy Dwyer and Robert F. Eagen, Jr. of the 

National Pretreatment Program are to be acknowledged for their valuable 

input. In addition, members of the Office of General Counsel and other 

members of the Effluent Guidelines Division and Office of Water Enforcement 

and Permits Division are acknowledged for their important c()ntributions. 

This document\was prepared by JRB Associates and Whitescarver Associates, 

Inc. under EPA Contract No. 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 ............................ 5-2 
TABLE 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 by Metal 

Finishing Category Unit Operations ........................... 

Pretreatment Standards for the Metal Finishing Category ...... 

Long Term Concentration Averages ............................. 

Compliance Dates for Metal 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 

4-2 
i. INTRODUCTION 

The National Pretreatment Program establishes an overall strategy for 

controlling the introduction of nondomestic wastes to publicly owned treatment 

works (POTWs) in accordance with the overall objectives of the Clean Water 

Act. Sections 307(b) and (c) of the Act authorize the Environmental Protection Agency to develop 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 to prevent the discharge of pollutants which pass through, interfere with, 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 EPA was required to develop Categorical Pretreatment Standards for 

34 industrial categories with a primary 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 

and Metal 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 and Metal 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 OF THE ELECTROPLATING AND METAL FINISHING CATEGORICAL 

PRETREATMENT STANDARDS 

There are 13,500 plants in the electroplating/metal finishing industry. 

Many discharge wastewaters from several metal 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 to wastestreams from most other metal finishing operations 

within the same plants. The Part 433 PSES will apply only to plants already 

covered by Part 413; however Part 433 will often cover additional wastewater 

within the same plants. Thus the Part 433 limits on discharge of toxic 

metals, toxic organics, and cyanide will apply to most faciiities in the 

electroplating/metal finishing industry. 

The industry can be divided into the sectors indicated on Table I.I. 

Facilities are either "captives" (those which in a calendar year own more than 

50% [area basis] of the materials undergoing metal finishing); or "job shops" 

(those which in a calendar year do not own more than 50% [area basis] of material undergoing metal finishing). 

Captives can be further divided by two definitions: "integrated" plants 

are those which, prior to treatment, combine electroplating waste streams with 

significant process waste streams not covered by the electroplating category; 

"non-lntegrated" facilities are those which have significant wastewater discharges only from operations addressed by the electroplating category. Many 

captives (50%) are "integrated" facilities. Whereas captives often have a 

complex range of operations, job shops usually perform fewer operations. In 

theory job shops can be divided like captives; in actuality, however, approximately 97% of all job shops in this industry are "non-integrated." 

Pretreatment standards for the electroplatlng industry were first 

established in 1974 but it was not until promulgation of 40 CFR Part 413 on 

September 7, 1979 that Electroplating Categorical Pretreatment Standards 

became a reality. The 1979 Standards established specific numerical limitations for dischargers falling within seven subcategories. Shortly thereafter, 

I"--2 
Table I.I 

BREAKDOWN OF THE ~ ~ 

ELECTROPLATING/METAL FINISHING INDUSTRY 

(Number of plants per sector 13,470) 

Job shops] 

and IPCBM-

(3,470) 

Captive facilities (I0,000) 

Nonintegrated Integrated 

Indirect 3,061 job & 3,750 non- 3,750 

dischargers IPCBM indirect integrated integrated 

(10,561) captive captive 

Direct 409 job & 

dischargers IPCBM 

~(2,909) directs 

(2) (2) 

1 Independent printed circuit board manufacturers. 

2 2,500 captive directs. 

I-3 
petitions to review the electroplating pretreatment standards were filed in 

the Court of Appeals by several industry groups. EPA reached a settlement 

agreement with the industry groups and agreed to adopt changes to the Standards which were promulgated on January 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 1.9 mg/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 as many 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, the Agency would not impose more stringent pretreatment 

standards for that segment of the industry for several years. 

In accordance with the Agency's plan, EPA promulgated the Metal Finishing 

Categorical Pretreatment Standards on July 15, 1983 as 40 CFR Part 433. The 

effect of the 1983 Metal Finishing Standards was to create a new category -

Metal Finishing - which most electroplaters would have to comply with following their compliance with the Electroplating Standard. These subsequent 

limits would apply uniformly to discharges from electroplating and other metal 

finishing operations. This would meet industry's requests for equivalent 

limits for process lines often found together and would greatly reduce the 

need for the combined wastestream formula (see Section 5.5). Once the compliance date for the Metal Finishing Standards is reached, all firms, conducting one or more of the six basic operations of the Electroplatlng Category 

(see Section 2.1) must come into compliance with the Metal 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 433 Metal Finishing Standards. 

I-4 
fl 

/ 

11 

Non-integrated and integrated electroplaters must comply with Electroplating Pretreatment Standards for Existing /Sources (PSES) for Metals and 

Cyanide by April 27, 1984; and June ~0~ 1984, respectively. All electroplaters must comply with the Total Toxic Organics (TTO) PSES by no later than 

July 15, 1986 (See Table 2.2). 

Electroplaters subject to the Metal Finishing PSES must comply with the 

Metals, Cyanide, and Final TTO PSES by no later than February 15, 1986 (See 

Table 3.5). After this date, the Metal Finishing PSES supercede the Electroplating PSES. With the exception of plants covered by the Iron and Steel 

standards, electroplaters subject to the Metal Finishing PSES must comply with 

an interim TTO PSES by no later than June 30, 1984. A more complete discussion of compliance dates is presented in subsequent sections of this 

manual. 

1-5 
2. ELECTROPLATING CATEGORICAL PRETREATMENT 

STANDARDS (40 CFR PART 413) 

2.1 AFFECTED INDUSTRY 

The Electroplatlng Standards are applicable to wastewater from any or all 

of these six specific operations (See the Electroplating Final Development 

Document). 

i. Electroplating 

2. Electroless Plating 

3. Anodizing 

4. Coatings 

5. Chemical Etching and Milling 

6. Printed Circuit Board Manufacturing 

These six electroplating operations are briefly discussed below: 

I. 

. 

Electr~plating is the production of a thin surface coating of on~ 

metal upon another by electrodeposition. Ferrous or nonferrous basis 

materials may be coated by a variety of common (copper, nickel, lead, 

chromium, brass, bronze, zinc, tin, cadmium, iron, aluminum or 

combinations thereof) or precious (gold, silver, platinum, osmium, 

iridium, palladium, rhodium, indium, ruthenium, or combinations 

thereof) metals. In electroplatlng, metal ions supplied by the 

dissolution of metal from anodes or other pieces, are reduced on the 

work pieces (cathodes) while in either acid, alkaline, or neutral 

solutions. 

The eleetroplatlng baths contain metal salts, alkalies, and other 

bath control compounds in addition to plating metals such as copper, 

nickel, silver or lead. Many plating solutions contain metallic, 

metallo-organic, and organic additives to induce grain refining, 

leveling of the plating surface, and deposit brightening. 

Electroless Plating is the chemical deposition of a metal coating on 

a workplece by immersion in an appropriate plating solution. 

Electricity is not involved, therefore uniform deposits are easily 

obtained. Copper and nickel electroless plating for printed circuit 

boards are the most common operations. In electroless nickel plating 

the source of nickel is a salt, and a reducer is used to reduce the 

nickel to its base state. A complexlng agent is used to hold the 

metal ion in solution. Immersion plating, which for purposes 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 or ammonia). 

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, 

the wastewaters will contain chromium or other metals from the dye. 

Other potential pollutants include nickel acetate (used to seal 

anodic coatings) or other complexes and metals 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, a portion 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 to produce a decorative 

finish. A variety of solutions utilizing many metals may contribute 

to the wastestream. Passivating is the process of forming a protective film on metals by immersion in an acid solution, usually nitric 

acid or nitric acid with sodium dichromate. 

Etching and Chemical Milling are processes used to produce specific 

design configurations or surface appearances on parts 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 

major wastestream constituents are the dissolved basis material and 

etching solutions. 

Printed Circuit Board Manufacturln~ involves the formation of a 

circuit pattern of conductive metal (usually copper) on nonconductive 

board materials such as plastic or glass. There are five basic steps 

2-2 
involved in the manufacturing of printed circuit boards: cleaning 

and surface preparation, catalyst and electroless plating, pattern 

printing and masking, electroplating, and etching. 

Wastewater is produced in the manufacturing of printed circuit boards 

from the following processes: 

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, copper plating, and solder plating. 

d. Etching - Rinses following etching and solder brightening. 

e. Tab plating - Rinses following solder stripping, scrubbing, acid 

cleaning, and nickel, gold, or other plating operations. 

f. Immersion plating - Rinses following acid cleaning and immersion 

tin plating. 

Additionally, water may be used for subsidiary purposes such as 

rinsing away spills, air scrubbing Water, equipment washing, and 

dumping spent process solutions. The principal constituents of the 

wastestreams from the printed circuit board industry are suspended 

solids, copper, fluorides, phosphorus, tin, palladium, and chelating 

agents. Low pH values are characteristic of the wastes because of 

the necessary acid cleaning and surface pretreatment. 

In addition to t~e above operations, the Electroplating Standards also J 

apply to the related operations of alkaline cleaning, acid pickle, and 

stripping when each operation is followed by a rinse. 

2.2 EXCEPTIONS FROM REGULATION COVERAGE 

Operations similar to electroplating which are specifically exempt from 

coverage under the Electroplating Categorical Pretreatment Standards include: 

I. Electrowinning and electroreflning conducted as part of nonferrrous 

metal smelting and refining (40 CFR Part 421); 

2-3 
2. 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 on milligrams 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 or more of regulated Electroplating process wastewater. 

Also, all new sources which perform electroplatlng operations are subject 

to the Metal Finishing regulations (40 CFR Part 433). 

2-4 
TABLE 2.1 

PRETREATMENT STANDARDS FOR EXISTING SOURCES (PSES) 

ELECTROPLATING CATEGORY 

Facilities Dischargin~ <38,000 liters (1.2,000 gallons) per day 

Pollutant ," 

Cadmium (T) 

Lead (T) 

Cyanide, A 

Total Toxic Organics (TTO) 1 

Daily Maximum 

1.2 

0.6 

5.0 

4.57 

Maximum 

4 Day Average 

(mgll) 

0.7 

0.4 

2.7 

m--

Facilities Discharging >38,O00 liters (I0,000 gallons) per day 

Pollutant 

Daily Maximum 

(mgll) 

Maximum 

4 Day Average 

(mg/l) 

Cadmium (T) 

Chromium (T) 

Copper (T) 

Lead (T) 

Nickel (T) 

Zinc (T) 

Silver (T) 2 

Total Metals 3 

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 the maximum 4-day average for TTO. 

2The silver pretreatment standard applies only to precious metals plating. 

3Total metals is defined as the sum of 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 or more 

Pollutant 

Daily Maximum 

(mg/sq m of Operation) 

Electroplating, 

Electroless 

Plating, 

Chemical Etching 

and Milling, 

Coatings, 

Anodizing 

Maximum 4 Day Average 

(mg/sq m of O~eration) 

Electroplating, 

Electroless 

Plating, 

Printed Chemical Etching Printed 

Circuit and Milling, 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 ---

Total metals 2 410 935 267 609 

Cyanide (T) 74 169 39 89 

TTO - Maximum for any one day is 2.13 mg/l 

iThe silver pretreatment standard applies only to precious metals plating. 

2Total metals is defined as the sum of the masses of copper, nickel, total 

chromium, and zinc. 

2-6 
2.4 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 on which the limits 

are based. 

2.5 COMPLIANCE DATES 

The Agency divided the industry into two groups on the basis of wastewater 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 

or more electroplating process water lines with one or more 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 46 unit 

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 the Metal Finishing pretreatment regulations apply to wastewater from any of the 46 listed metal finishing operations. If a facility does not perform at least one of six Electroplating 

operations, it is not subject to the Metal Finishing regulation. These metal 

finishing unit operations are summarized and described in Table 3.1. Table 

3.2 summarizes the wastewaters potentially generated by each of the metal 

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 the Metal 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 the material 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 to minimize the economic 

impact to these relatively small facilities. Also excluded from the Metal 

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 CATEGORY UNIT OPERATIONS 

Unit Operations Summary Description of Unit Operations 

Lo 

I 

I. Electroplating 

2. Electroless Plating 

3. Anodizing 

4. Coatings 

The production of a thin surface coating of one metal upon another by 

electrodeposition. Ferrous or nonferrous basis materials may be coated 

by a variety of common (copper, nickel, lead, chromium, brass, bronze, 

zinc, tin, cadmium, iron, aluminum or combinations thereof) or precious 

(gold, silver, platinum, osmium, iridium, palladium, rhodium, indium, 

ruthenium, or combinations thereof) metals. In electroplating, metal 

ions supplied by the dissolution of metal from anodes or other pieces, 

are reduced on the work pieces (cathodes) while in either acid, alkaline, 

or neutral solutions. 

The chemical deposition of a metal coating on a workpiece by immersion in 

an appropriate plating solution in which electricity is not involved. 

Copper and nickel electroless plating for printed circuit boards are the 

most common operations. Immersion plating, which for purposes of the 

Metal Finishing regulation is considered part of electroless plating, 

produces a metal deposit by chemical displacement. 

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. 

Any operation that includes chromating, phosphating, metal coloring and 

passivating. In chromating, a portion 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 further processing. Metal coloring 

involves the chemical method of converting the metal surface into an 
TABLE 3.1. METAL FINISHING CATEGORY UNIT OPERATIONS (Continued) 

Unit Operations Summary Description of Unit Operations 

Lo 

I 

Lo 

5. Etching and Chemical Milling 

6. Printed Circuit Board 

Manufacturing 

7. Cleaning 

8. Machining 

9. Grinding 

oxide or similar metallic compound to produce a decorative finish. 

Passivating is the process of forming a protective film on metals by 

immersion in an acid solution, usually nitric acid or nitric acid with 

sodium dichromatel 

These operations are used to produce specific design configurations or 

surface appearances on parts 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 are usually much 

greater in chemical milling. 

This operation involves the formation of a circuit pattern of conductive 

metal (usually copper) on nonconductive board materials such as plastic 

or glass. There are five basic steps involved in the manufacturing of 

printed circuit boards: cleaning and surface preparation, catalyst and 

electroless plating, pattern printing and masking, electroplating, and 

etching. 

This operation involves the removal of oil, grease, and dirt from the 

basis material using water with or without detergents or other dispersing 

agents. Acid cleaning is a process in which an acid is used with a 

wetting agent or detergent to remove oil, grease, dirt, or oxide from the 

metal surface. 

This operation involves the general process of removing stock from a 

workpiece by forcing a cutting tool through the workpiece, thereby 

removing a chip of basis material. Machining operations incorporate the 

use of natural and synthetic oils for cooling and lubrication. 

This operation involves the process of removing stock from a workpiece by 

the use of a tool consisting of abrasive grains held by a rigid or semirigid binder. Natural and synthetic oils are used for cooling and 

lubrication in many grinding operations. 
TABLE 3.1. METAL FINISHING CATEGORY UNIT OPERATIONS (Continued) 

Unit Operations Summary Description of Unit Operations 

I 

I0. Polishing 

Ii. Barrel Finishing 

(or Tumbling) 

12. Burnishing 

13. Impact Deformation 

This abrading operation is used to remove or smooth out surface defects 

(scratches, pits, tool marks, etc.) that adversely affect the appearance 

or function of a part. Area cleaning and washdown can produce wastes 

that enter wastewater streams. The wastes would belong to the common 

metals and oily waste types. 

This operation is a controlled method of processing parts to remove 

burrs, scale, flash, and oxides as well as to improve surface finish. 

Barrel finishing produces a uniformity of surface finish not possible by 

hand finishing and is generally the most economical method of cleaning 

and surface conditioning. Wastewater is generated by rinsing of parts 

following the finishing operation and by periodic dumping of process 

solutions. Contributions to the common metals, hexavalent chromium, 

cyanide, and oily waste types could be made by this operation, depending 

upon the chemical solutions employed. 

This operation involves the process of finish sizing or smooth finishing 

a workpiece (previously machined or ground) by displacement, rather than 

removal, of minute surface irregularities. Wastes may come from spills, 

leaks, process solution dumps and post-finish rinsing and could contribute to the common metals, precious metals, and oily waste types 

depending upon the basis material finished. In addition, sodium cyanide 

(NaCN) may be used as a wetting agent and rust inhibitor (for steel), 

thus contributing cyanide wastes from this o~eration. ,z 

This operation involves the process of applying an impact force to a 

workpiece such that the workpiece is permanently deformed or shaped. 

Wastes containing conmlon metals and oily wastes may 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. We Id ing 

This operation involves the process of applying force (at a slower rate 

than at impact force) to permanently deform or shape a workpiece. 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 a workpiece by 

forcing a sharp edge or opposed sharp edges into the workpiece stressing 

the material 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 the modification 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 as well 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 or more 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 of water 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 of Unit Operations 

t~J 

I 

C~ 

19. Brazing 

20. Soldering 

21. Flame Spraying 

22. Sand Blasting 

This operation involves the process of joining metals by flowing a thin, 

capillary thickness layer of nonferrous filler metal into the space 

between them. Bonding results from the intimate contact produced by the 

dissolution of a small amount of base metal in the molten filler metal, 

without fusion of the base metal. The term brazing is used where the 

temperature exceeds 425°C (800°F). This operation is followed by 

quenching, cooling or annealing in a solution of water or emulsified 

oils. When this is done, wastes produced can belong to the common metals 

waste type. 

This operation involves the process of joining metals by flowing a thin 

(capillary thickness) layer of nonferrous filler metal into the space 

between them. Bonding results from the intimate contact produced by the 

dissolution of a small amount of base metal in the molten filler metal, 

without fusion of the base metal. The term soldering is used where the 

temperature range falls below 425°F (800°F). This operation is followed 

by quenching, cooling or annealing in a solution of water or emulsified 

oils. When this is done, wastes produced can belong to the common metals 

waste type. 

This operation involves the process of applying a metallic coating to a 

workpiece using finely powdered fragments of wire, together with suitable 

fluxes, which are projected through a cone of flame onto the workpiece. 

This operation is followed by quenching, cooling or annealing in a 

solution of water or emulsified oils. When this is done, wastes produced 

can belong to the common metals waste type. 

This operation involves the process of removing stock, including surface 

films, from a workpiece by the use of abrasive grains pneumatically 

impinged against the workpiece. 
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 a mechanical 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 of work areas and contributes to the common metals and oily 

waste types. 

This operation is a process which can remove metal from any metal with 

good dimensional control. The machining action is caused by the 

formation of an electrical spark between an electrode, shaped to the 

required contour, and the workpiece. Rinsing of machined 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 a process 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 the metal. In addition to standard chemical 

formulations, inorganic and organic solvents are sometimes used as 

electrolytes for electrochemical machining and with 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 the material locally and is 

generally carried out in a vacuum. 
TABLE 3.1. METAL FINISHING CATEGORY UNIT OPERATIONS (Continued) 

Unit Operations Summary Description of Unit Operations 

I 

OO 

27. Laser Beam Machining 

28. Plasma Arc Machining 

29. Ultrasonic Machining 

30. Sintering 

31. Laminating 

32. Hot Dip Coating 

This operation is the process whereby a highly focused monochromatic 

collimated beam of light is used to remove material at the point of 

impingement on a workpiece. Laser beam machining is a thermoelectric 

process with material removal largely accomplished by evaporation, 

although some material is removed in the liquid state at high velocity. 

This operation is the process of material removal or shaping of a 

workpiece by a high velocity jet of high temperature ionized gas. A gas 

(e.g., nitrogen, argon, or hydrogen) is passed through an electric arc 

causing it to become ionized and raised to temperatures in excess of 

16,649°C (30,000°F). The relatively narrow plasma jet melts and 

displaces the workpiece material in its path. 

This operation is a mechanical process designed to effectively machine 

hard, brittle materials. It removes material by the use of abrasive 

grains which are carried in a liquid between the tool and the work, and 

which bombard the work surface at high velocity. 

This operation is the process of forming a mechanical part from a 

powdered metal by fusing the particles together under pressure and heat. 

The temperature is maintained below the melting point of the basis metal. 

This operation is the process of adhesive bonding layers of metal, 

plastic, or wood to form a part. Water is not often used in this 

operation; however, occasional rinsing or cooling may occur in conjunction with laminating. The waste generated could contribute to the common 

metals and oily waste types. 

This operation is the process of coating a metallic workpiece with 

another metal to provide a protective film by immersion in a molten bath. 

Galvanizing (hot dip zinc) is the most common hot dip coating. Water is 

used for rinses following precleaning and sometimes for quenching after 

coating. These wastewaters can contribute to the common metals 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 a metallic or non-metallic 

workpiece with thin films of metal. The surface to be 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 a metal or compound 

upon a heated surface by reduction or decomposition of a volatile 

compound at a temperature below the melting 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 of heat. 

This operation is the process of removing surface oxides or scale from a 

workpiece by immersion of the workpiece in a molten salt bath or a hot 

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 a workpiece 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 CATEGORY UNIT OPERATIONS (Continued) 

Unit Operations Summary Description of Unit Operations 

L~ 

I 

O 

38. Paint Stripping 

39. Painting 

40. Electrostatic Painting 

41. Electropainting 

42. Vacuum Metalizing 

43. Assembly 

This operation is the process of removing an organic coating from a 

workpiece. The stripping of such coatings is usually performed with 

caustic, acid, solvent, or molten salt. The stripping wastes can contain 

any of the constituents of the paint being removed, as well as a small 

amount of the basis material 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 oily waste types and may 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 an oppositely charged workpiece followed by thermal 

fusing of the paint particles to form a cohesive paint film. 

This operation is the process of coating a workpiece by either making it 

anodic or cathodic in a bath that is generally an aqueous emulsion of the 

coating material. Electropainting is used primarily for primer coats 

because it giyes a fairly thick, highly uniform, corrosion resistant 

coating in relatively little time. Ultrafiltration is used in connection 

with electropainting to concentrate paint solids. Wastewaters from these 

unit operations can contribute to the common metals, hexavalent chromium, 

and solvent waste types. 

This operation is the process of coating a workpiece with metal by flash 

heating metal vapor in a high-vacuum chamber containing the workpiece. 

The vapor condenses on all exposed surfaces. 

This operation involves the fitting together of previously manufactured 

parts or components into a complete machine, unit of a machine, 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 as well as heavy metal 

contamination derived from the component being tested. These wastewaters 

can contribute to the common metals and oily waste types. 

This operation is the process of depositing metal coatings on a workpiece 

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 the Metal Finishing 

regulation. 
TABLE 3.2 

POTENTIAL WASTEWATER POLLUTANTS GENERATED BY METAL FINISHING 

UNIT OPERATIONS 

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 

Conversion Coating 

Etching (Chemical Milling ) 

Printed Circuit Board Manufacturing 

Cleaning 

Machining 

Grinding 

Polishing 

Barrel Finishing (Tumbling) 

Burnishing 

Impact Deformation 

Pressure Deformation 

Shearing 

Heat Treating 

Thermal Cutting 

Welding 

Brazing 

Soldering 

Flame Spraying 

Sand Blasting 

Other Abrasive Jet Machining 

Electric Discharge Machining 

Electrochemical Machining 

Electron Beam Machining 

Laser Beam Machining 

Plasma Arc Machining 

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 

X 
TABLE 3.2 

POTENTIAL WASTEWATER POLLUTANTS GENERATED BY METAL FINISHING 

UNIT OPERATIONS 

Unit Operations 

Hexavalent 

Metals Chromium Cyanide Oils 

Toxic 

Organics 

Zero 

Discharge 

Lo 

I 

LO 

29. Ultrasonic Machining 

30. Sintering 

31. Laminating 

32. Hot Dip Coating 

33. Sputtering 

34. Vapor Plating 

35. Thermal Infusion 

36. Salt Bath Descaling 

37. Solvent Degreasing 

38. Paint Stripping 

39. Painting 

40. Electrostatic Painting 

41. Electropainting 

42. Vacuum Metalizing 

43. Assembly 

44. Calibration 

45. Testing 

46. Mechanical Plating 

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 

X 
In certain cases, another Categorical Pretreatment Standard may also 

cover wastewater discharges from metal 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 a porcelain 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 - cleaning 

i - pickling 

- immersion plating 1 

1 - chemical coating 

Porcelain Enameling 

- steel coating 

®2 

A.B 2 

Wastewater to Discharge 

These four operatlons are normally subject to the Metal Finlshing regulation; however, in this case, they are performed immediately prior to a 

porcelain enameling operation. These types of operations were included 

as part of the data base 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 the wastestreams are combined before 

discharge, the combined discharge (A+B) is subject to the combined wastestream formula. 

FIGURE 3.1 

SCHEMATIC SHOWING EXAMPLE OF OVERLAP COVERAGE OF CATEGORICAL 

STANDARDS AT INTEGRATED FACILITIES 

3-15 
metal 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 then with 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 is not 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 to use the Combined Wastestream Formula. No production based standards were developed for 

the Metal 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 per month) average concentration limitations. The PSES and PSNS limitations for metal finishing facilities are 

presented in Table 3.3. If a plant 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 on which the limits 

are based. 

3-16 
TABLE 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 TERM CONCENTRATION AVERAGES 

Pollutant of Pollutant Property 

Long Term 

Concentration 

Average 

Milligrams 

Per Liter 

(mg/l) 

Cadmium (T) I 

Chromium (T) 

Copper (T) 

Lead (T) 

Nickel (T) 

Silver OT) 

Zinc (T) 

Cyanide (T) 

Cyanide, A 

TTO (raw water) 

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) for new sources is 0.058 mg/l. 

3-18 
3.5 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 to prevent organics 

from being completely uncontrolled during the time before final compliance. 

The Metal Finishing compliance dates are shown in Table 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 the waterways. 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 FOR METAL FINISHING PRETREATMENT STANDARDS 

40 CFR PART 433 

Pollutant 

Parameter 

Interim TTO 1 

Metals, Cyanide, 

and Final TTOExisting Sources New 

Capitives Sources 

June 30, 19842 

February 15, 1986 on commencement 

of discharge 

ITTO = Total Toxic Organics 

2july I0, 1985 for plants covered by 40 CFR Part 420, Iron and Steel 

3-20 
4. TREATMENT TECHNOLOGIES 

The treatment technologies described in this section are currently used 

by metal finishers/electroplaters to remove or recover wastewater pollutants 

normally generated. Figure 4.1 is an example of the current technology commonly used for treatment of metal finishing wastewater. 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 common metals. Wastestream segregation can 

reduce the flow of wastewater 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 dissolved metals 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 cyanide will interfere with the 

system's ability to remove the dissolved metals. These raw waste 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 system plus 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 common metals removal, to be used in 

conjunction with or in place of the preceeding methods, include peat adsorption, insoluble starch xanthate filtration, sulfide precipitation, flotation, 

and membrane 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 I L - .__..J L_.,._._.J i I T ~,~-! : ~ 1 / ,Ig / ; , _ - / I / . ...l.d o. 

-- -- Without Cyanide I~¢lalmad I: ........ '_L___L ....... f 

Waste DI scharqe 

(11~latment System 

Influent) t 

"-- i- ........ 1 

L ...... J /...... / 

~ Ibst.e 

(Ck~mn I~tals) 

r- ..... -I 

i mtali .

L._-~_':J 

F ~tod 

! 

Pinsl IYeatad 

Effluent 

! 

I 

I 

t 

t~auled Or 

I~claimd 

FIGURE 4.1 

WASTEWATER TREATMENT SCHEMATIC 

~o~mal l~ute 

..... Optional Itoute 

Mote~ Diacharqe [Ntam precious metals t~owty my be 

hauled in alternative ~m~, depmdlng (;n the 

recovery method In tree. 
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 a product 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 a process 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 form metallic 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 system performance in the removal of complexed heavy 

metals. The ferrous sulfate technique is capable of achieving low metal 

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 the metal. 

4-3 
lon exchange is the process in which 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 in which 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. In most cases, gaseous sulfur dioxide is used as the reducing agent in 

the reduction of hexavalent chromium which 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 in products 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. 

4-4 
4.6 TREATMENT OF OILY WASTES 

Techniques commonly used by electrolaters and metal finishers to remove 

oils include skimming, coalescing, emulsion breaking, flotation, centrifugation, ultrafiltration, and reverse osmosis. Treatment of oily wastes 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 the waste 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 in wastewater. 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 

be more soluble in oil and grease than in water. 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 of metals, 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. 

4-5 
4.8 TREATMENT OF SLUDGES 

Sludges are created by waste treatment technologies which remove solids 

from wastewater. 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 material which is impenetrable to the solid phase. Sludge bed drying is employed to 

reduce the water content of sludges so that they can be mechanically 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 the water usage at metal finishing facilities is the most 

important control and results in reduced pollutant discharge and consequently 

reduced costs for wastewater treatment. It is estimated that rinse steps 

consume most of the water used at metal finishing facilities. Therefore, 

efficient rinse systems would lead to the greatest water use reductions. 

Several rinsing techniques are currently used at metal finishing facilities. 

4-6 
Of these, the countercurrent rinse provides for the most efficient water 

usage, and consists of only one fresh water 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 lower water usage. 

4-7 
5. REQUIREMENTS OF THE GENERAL PRETREATMENT REGULATIONS 

5.1 INTRODUCTION 

This section provides a brief 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 and Metal Finishing category. 

The General Pretreatment Regulations for Existing and New Sources (40 CFR 

Part 403) establish the framework and responsibilities for implementation of 

the National Pretreatment Program. The effect of 40 CFR Part 403 is essentially three-fold. First, the General 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 POTW whether 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, and most 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-i 
5.2 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 a particular industry category or subcategory and 

is subject to a categorical pretreatment standard. Although the deadline for 

submitting a category determination request by existing industrial users 

subject to the electroplating and metal 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 and Metal 

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 BMR will be submitted to the 

State (if the State has an approved State Pretreatment Program) or to the EPA 

Region. Additional guidance on BMR reporting is available from the EPA 

Regional Pretreatment Coordinator. 

5-2 
BMR 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 and metal finishing BMRs. 

BMR Content 

A BMR must 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 

diagram which indicates points of discharge from the regulated 

processes to the POTW. 

Flow measurement information for regulated process streams discharged 

to the municipal system. Flow measurements 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 (or mass, 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 two week period. Where the flow of the stream is greater 

than 250,000 gallons per day, the industrial user must take six samples within a two week 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 other wastestreams 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 

DUE DATES 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 been made, then the BMR is due 180 days 

after the final decision on the category determination. 

5-4 
6. Statement of certification concerning compliance or noncompliance 

with the Pretreatment Standards. 

. If not in compliance, a compliance schedule must be submitted with 

the BMR that describes the actions the user will 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 of major 

events, however, no increment of the schedule shall exceed 9 months. 

Within 14 days of each completion date in the schedule, the industrial user shall submit a progress report to the Control Authority 

indicating whether or not it complied with the increment of progress 

to be met on such date, and, if not, the date on which it expects to 

comply with this increment of progress and the steps being taken to 

return to the schedule. 

BMR Reporting of Toxic Organics 

Since promulgation of the Metal 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 TTO will 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 BMR monitoring, the 

regulations allow for the IU to certify that the regulated toxic organics are 

not used at the facility or to present a plan demonstrating appropriate controis to prevent organic compounds from entering the wastestream. 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 TTO monitoring is required for the BMR. 

5.3.2 Report on Compliance 

Within 90 days after the compliance date for the Electroplating and Metal 

Finishing Pretreatment Standards or in the case of a New Source following 

commencement of the introduction of wastewater 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 

5-5 
are 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 of whether 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 and Metal 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 to notify 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 and Analysis to Demonstrate Continued Compliance 

Section 403.12(g) states that the frequency of monitoring to demonstrate 

continued compliance shall be prescribed in the applicable Pretreatment Standard. Neither the Electroplating nor Metal Finishing Pret~eatment Standard 

establish any monitoring 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, the monitoring frequency established by the Control Authority shall be used in the baseline monitoring report (403.12(b)(5)), 

5-6 
the 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 or using 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 any monitoring activities required by 403.12 for a minimum 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 and Metal Finishing regulations to certify 

that no dumping of toxic organics to the wastestream has occurred. In cases 

where monitoring to determine TTO compliance is necessary, sampling and 

analysis for TTO will 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 no monitoring be required, 

they must submit a toxic organic management plan that specifies the toxic 

organic compounds used, the method of disposal used (instead of dumping into 

5--7 
wastestreams), and procedures for assuring that toxic organics do not routinely spill or leak into wastewater discharged to the POTW. This certification 

is added as a comment to the baseline monitoring report as well 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 organic management 

plan that is required when industrial users wish to certify that no discharge 

of toxic pollutants has occurred is presented below. 

The plan has 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 possible wastewater sources; 

c. A list of raw materials used in the industrial processes, including 

chemical additives, water treatment chemicals and cleaning agents, 

and the wastewater stream that each material potentially enters; 

d. Comparison of the toxics found in the effluent with the list of raw 

materials and selection of the most 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 raw materials 

impurities contributing inorganic pollutants. 

Step 2 - Pollutant control evaluation should be determined on a case-bycase basis and may include: 

a. Inplant process modification, including chemical substitution, 

partial or complete recycling, reuse, neutralization, ion exchange, 

or operation changes. 

5-8 
Step 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 in meeting 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 to Metal 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) [40 CFR 403.6(e)]. The CWF is a mechanism for calculating 

appropriate limitations specified in applicable regulations to a wastewater in 

which process wastestreams are mixed with regulated, unregulated or dilution 

streams, thereby resulting in a mixed 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. 

5-9 
Definitions 

• 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 a wastestream, usually expressed in mg/l (ib/gal). 

Mass-based Limit - a limitation based on the actual quantity of a 

pollutant in a wastestream, usually expressed in mg/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 a municipality 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 a prior 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. 

5-10 
If 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 IU must either: i) not combine the 

dilute streams before they reach the combined treatment facility, or 

2) segregate all wastestreams 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 a maximum monthly average 

(based on i0 sample days) standard. According to 40 CFR Part 413.04, 

if a non-electroplating wastestream is regulated by a monthly 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 to monthly 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 

5-11 
Monitoring 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 in Table 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 applie d 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 system with 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 to grant 

removal credits and specifies the means by which these removal credits are to 

be determined. 

In 1977, Congress amended section 307(b) of the Clean Water Act to 

provide for removal credits. EPA originally implemented that provision and 

established the conditions under which POTWs could obtain authorization to 

5-12 
TABLE 5.2 

COMBINED WASTESTREAM FORMULAS 

Alternative Concentration Limit Formula: 

C 

t illi i : ciFi Fl I x IFtFdFt 

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) 

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. 

5-13 
TABLE 5.3 

COMBINED WASTESTREAM FORMULA EXAMPLE CALCULATION 

The following examples provide the calculations for determining alternat 

discharge limits using the combined wastestream formula. The examples assume 

combinations of various industries with the following wastestreams: 

Industrial Daily Max. 

Category Wastestream Flow Zn Limit 

(Subcategory) Type (mgd) (mg/l) 

2 

Electroplating Regulated 0.4 4.2 

(Common Metals) 

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 

tion Based 4 

Sanitary Waste Dilution 0.05 N/A N/A 

iThese are not subcategories; they are metal finishing processes. 

2Alternate production based limit = 164 mg/m 2 plated. 

3Alternate Mass/Production based limits = 53.3 mg/m 2 for preparation and 0.85 

mg/m 2 for coating. 

4 

Mass/Production based limits = 0.943 mg/off-kg of copper heat treated for 

solution heat treatment. 

The calculated alternate discharge limits (Zn ) in the following examples cwf 

are based on phased compliance dates for Electroplating, Porcelain Enameling, 

and Metal Finishing. 

5-14 
TABLE 5.4 

COMBINED WASTESTREAM FORMULA EXAMPLE CALCULATION 

EXAMPLE A 

Alternative discharge limit for integrated electroplater/porcelain 

enameler from June 30, 1984 (compliance date for electroplating) until 

November 25, 1985 (compliance date for porcelain enameling). 

E1ectroplating I I Metal Finishing 

(Common Metals) I I(C°ating & Painting) 

Q = 0.4 mgd 

Zn = 4.2 mg/l 

Q = 0.1 mgd 

Zn = N/A 

Q = 0.075 mgd 

Zn = N/A 

Porcelain I 

Enameling (Steel)} I I . Swn~ttary

l 

Q = 0.05 mgdI 

Zn N/A J 

Zn cwf 

(4.2 mg/l x 0.4 m~d) X (0.4 mgd + 0.1 mgd + 0.075 mgd + 0.05 mgd - 0.05 mgd) 

0.4 mgd 0.625 mgd 

Zn = 3.86 mg/l cwf 

Note: Due to dilution from sanitary waste, the applicable Zn limit, 4.2 mg/l, 

is reduced to 3.86 mg/l. 

5-15 
TABLE 5.4 (Continued) 

COMBINED WASTESTREAM FORMULA EXAMPLE CALCULATION 

EXAMPLE B 

Alternative discharge limit for integrated electroplater/porcelain 

enameler from November 25, 1985 until February 15, 1986 (compliance date for 

metal finishing) 

Electroplating I I Metal Finishing I 

(Common Metals) [ l(Coating & Painting) I 

Porcelain 

Enameling (Steel) 

Sanitary 

Waste 

Q = 0.4 mgd 

Zn = 4.2 mg/1 

Zncwf 

I Q = 0.I mgd Q = 0.075 mgd 

Zn = N/A Zn = 1.33 mg/l 

1 

4.2 mg/1 (0.4 ~gd) + 1.33 mg/1 (0.075 mgd) X 

(0.4 mgd + 0.075 mgd) 

Q = 0.05mgd 

Zn = N/A 

(0.4 mgd + 0.I mgd + 0.075 mgd + 0.05 mgd - 0.05 mgd) 

0.625 mgd 

Zncwf = 3.45 mg/l 

Note: Alternate discharge limit is based on Electroplatlng and Porcelain 

Enameling categorical standards and proportioned by the flow of the 

regulated electroplatlng and porcelain enameling wastestreams. Due to 

dilution from sanitary waste, the alternate discharge limit is reduced. 

5-16 
TABLE 5.4 (Continued) 

COMBINED WASTESTREAM FORMULA EXAMPLE CALCULATION 

EXAMPLE C 

Alternative discharge limit for integrated electroplater/porcelain 

enameler after February 15, 1986 (compliance date for metal finishing). 

I Metal Finishing I Metal Finishing I 

(Electropiating I (Coating & Painting)l, 

Common Metals) ~ 

Q = 0.4 mgd 

Zn = 2.61 mg/l 

Zncwf 

Porcelain 

Enameling (Steel) 

Q = 0.i mgd Q = 0.075 mgd 

Zn = 2.61 mg/1 Zn = 1.33 mg/l 

2.61 mg/l (0.5 mgd) + 1.33 m$/l (0.075 m~d) X 

(0.5 mgd + 0.075 mgd) 

Sanitary 

Waste 

Q = 0.05 mgd 

Zn = N/A 

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

0.625 mgd ° 

Zncwf = 2.25 mg/l 

Note: Electroplating (common metals) is now covered by Metal Finishing, and 

is subject to a Zn limit of 2.61 mg/1. Thus, the alternate discharge 

limit is based on Metal Finishing and Porcelain Enameling categorical 

standards and proportioned by the flow of the three regulated wastestreams. Due to dilution from sanitary waste, the alternate discharge 

limit is reduced to 2.25 mg/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 be used 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 12 months 

= 30,000 off-kg of copper heat 

treated per day 

Average Daily Water Usage in 

Solution Heating Treating 

During Last 12 months 

400,000 gpd 

Step i: Convert Production-based Limit to Equivalent Concentration Limit 

Concentration 

Equivalent 

(Production-Based Limit)(Avg. Daily Production Rate) 

(Avg. Daily Flow from Regulated Process) (Conversion Factor) 

0.943 mg/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 can be calculated as in Example A. 

I l Copper(solutionFOrmingHeat (Coating etaiFinishing & Painting)[ naelingP°rcelain (Steel) pSaltry

Treatment) 

Q = 0.4 mgd I Q = 0.i mgd I Q = 0.075 mgd 1 Q = 0.05 mgd 

Zn = 0.019 mg/l Zn = 2.61 Zn = 1.33 Zn = N/A 

(0.019 mg/l x 0.4 mgd) + (2.61 mg/l x 0.I mgd) + (1.33 mg/l x 0.075 mgd) Zn = cwf (0.4 mgd + 0.1 mgd + 0.075 mgd) X 

(0.4 mgd + 0.I mgd + 0.075 mgd + 0.05 mgd - 0.05 mgd) 

0.625 mgd 

Zn = 0.59 mg/l cwf 

Note: Off-kg shall mean the mass of copper ore copper alloy removed from a forming 

or ancillary operation at the end of a process cycle for transfer to a 

different machine or process. 

5-18 
TABLE 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 £o mass-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 12 months 

= 30,000 off-kg of copper heat 

treated per day 

Average Daily Water Usage in 

Solution Heat Treating 

During Last 12 months 

Allowable Zn Mass = 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 12 months 

= 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/m 2 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 12 months 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 Zn Mass 

= 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 

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

5-20 
grant 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 the Approval 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 in March 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 by which 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 a variance (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. 

5-21 
5.8 LOCAL LIMITS 

Local limits are numerical pollutant concentration or mass-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 a minimum 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 POTW which 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 to meet 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 

5-22 
States 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 progra m has the following 

capabilities to aid the POTW~in limit development: 

• Performs the four-step limit setting analysis on microcomputer or 

mainframe 

• Screens input data provided by the POTW 

Supplements POTW data with "built-in" files containing data on 

Industrial~Municipal wastewater characteristics, POTW removal rates, 

and POTW inhibition values 

5-23 
Allocates 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 

Final Regulations Promulgated 

Correction Notice (Typographical errors) 

Correction Notice 

(Delayed compliance for Integrated Facilities) 

Revision to 9/07/79 Promulgation of 7/03/80 

Amended (Integrated Facilities Compliance) 

Amended (Added total toxic organic limit) 

Amended (Allows PSES compliance beyond 7/1/84) 

Correction/Clarification Notice 

(Compliance Dates) 

Federal Register Notice 

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 (Allows PSES Compliance beyond 7/I/84 

Correction/Clarification Notice 

(Compliance Dates) 

Correction Notice (Typographical Errors) 

07/15/83 48FR32485 

09/15/83 48FR41410 

09/26/83 48FR43681 

10/03/83 48FR45105 

General Pretreatment Regulations 

40 CFR Part 403, 46 FR 9404 01/28/81 

Final Development Document -

Electroplating 

Final Development Document -

Metal Finishing 

August 1979 

June 1983 

440/1 - 79/003 

440/1 - 83/091 

Guidance Manual for POTW 

Pretreatment Program Development 

Procedures Manual for Reviewing 

a POTW Pretreatment Program 

Submission 

October 1983 

October 1983 

Copies of the technical and economic documents may be obtained from the 

National Technical Information Services, Springfield, VA. 22161 

(703/487-4650). Pretreament Program Manuals may be obtained from U.S. EPA, 

Permits Division (EN-336), Washington, D.C. 20460 

R-1 
Unded States 

Enwronmental Protection 

Agency 

Washmgton DC 20460 

Official Business 

Penalty for Private Use $300 

SDec=al 

Fourth-Class 

Rate 

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