Z

United States

Environmental Protection

Agency

The 2014 Annual Effluent 

Guidelines Review Report

July 2015
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U.S. Environmental Protection Agency

Office of Water (4303T)

1200 Pennsylvania Avenue, NW

Washington, DC 20460

EPA-821-R-15-001
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Table of Contents

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TABLE OF CONTENTS

Page

PART I: INTRODUCTION ..........................................................................................................I

1. 2014 ANNUAL REVIEW EXECUTIVE SUMMARY..................................................1-1

1.1 References for 2014 Annual Review Executive Summary......................1-4

2. BACKGROUND......................................................................................................2-1

2.1 The Clean Water Act and the Effluent Guidelines Program....................2-1

2.2 Effluent Guidelines Review and Planning Process..................................2-2

2.2.1 Effluent Guidelines Review and Prioritization Factors............... 2-3

2.2.2 Annual Review Process ............................................................... 2-3

2.2.3 Effluent Guidelines Program Plans............................................ 2-11

2.3 References for Background....................................................................2-12

PART II: EPA’S 2014 ANNUAL REVIEW METHODOLOGY AND ANALYSES ...............................II

3. INTRODUCTION TO EPA’S 2014 ANNUAL REVIEW ............................................3-1

4. PUBLIC COMMENTS AND OTHER STAKEHOLDER INPUT ON THE FINAL 

2012 AND PRELIMINARY 2014 EFFLUENT GUIDELINES PROGRAM PLANS .......4-1

4.1 Public Comments and Stakeholder Input.................................................4-1

5. CONTINUED REVIEW OF SELECT INDUSTRIAL CATEGORIES.............................5-1

5.1 Continued Review of the Metal Finishing Category (40 CFR Part 

433) ..........................................................................................................5-1

5.1.1 Overview of Existing ELGs Related to Metal Finishing............. 5-2

5.1.2 Profile of Metal Finishing Operations in the U.S. ....................... 5-9

5.1.3 Potential ELG Applicability Issues and Other 

Considerations............................................................................ 5-27

5.1.4 Summary of Findings from EPA’s Continued Review of 

the Metal Finishing Category..................................................... 5-28

5.1.5 References for the Continued Review of the Metal 

Finishing Category..................................................................... 5-30

5.2 Targeted Review of Pesticide Active Ingredients Without Pesticide 

Chemical Manufacturing Effluent Limits (40 CFR Part 455) ...............5-34

5.2.1 Targeted Review of Pesticide Active Ingredients Without 

Pesticide Chemical Manufacturing Effluent Limits .................. 5-36

5.2.2 Summary of Findings from EPA’s Targeted Review of 

Pesticide Active Ingredients Without Pesticide Chemical 

Manufacturing Effluent Limits.................................................. 5-38

5.2.3 References for EPA’s Targeted Review of Pesticide Active 

Ingredients Without Pesticide Chemical Manufacturing 

Effluent Limits........................................................................... 5-39

5.3 Continued Review of Brick and Structural Clay Products 

Manufacturing........................................................................................5-40

5.3.1 Air Regulations for Brick and Structural Clay Products 

Manufacturing............................................................................ 5-40
Table of Contents

TABLE OF CONTENTS (Continued)

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5.3.2 2014 Annual Review of Brick and Structural Clay Products 

Manufacturing............................................................................ 5-41

5.3.3 Summary of Findings from EPA’s Review of Brick and 

Structural Clay Products Manufacturing ................................... 5-45

5.3.4 References for the Continued Review of Brick and 

Structural Clay Manufacturing .................................................. 5-45

6. NEW DATA SOURCES AND ADDITIONAL SUPPORTING ANALYSES.....................6-1

6.1 Review of Engineered Nanomaterials in Industrial Wastewater.............6-1

6.1.1 Literature Review and Research Methodology............................ 6-2

6.1.2 Overview of Nanomaterials......................................................... 6-4

6.1.3 Engineered Nanomaterial Production Methods, Volumes, 

and Potential Sources of Industrial Discharge ............................. 6-5

6.1.4 Fate, Wastewater Treatment, and Toxicity.................................. 6-6

6.1.5 Analytical Methods.................................................................... 6-10

6.1.6 Federal Research and the National Nanotechnology 

Initiative ..................................................................................... 6-12

6.1.7 Summary of Findings................................................................. 6-13

6.1.8 References for the Review of Engineered Nanomaterials in 

Industrial Wastewater ................................................................ 6-14

6.2 Review of Industrial Wastewater Treatment Technologies...................6-21

6.2.1 Industrial Wastewater Treatment Technologies Data 

Collection Results...................................................................... 6-22

6.2.2 Industrial Wastewater Treatment Technologies Database 

Structure and Data Elements...................................................... 6-24

6.2.3 Database Structure ..................................................................... 6-24

6.2.4 Data Elements Captured ............................................................ 6-26

6.2.5 Summary of Data Captured in IWTT ........................................ 6-27

6.2.6 References for the Review of Industrial Wastewater 

Treatment Technologies............................................................. 6-31

PART III: RESULTS OF EPA’S 2014 ANNUAL REVIEW ...................................................III

7. RESULTS OF THE 2014 ANNUAL REVIEW............................................................7-1

7.1 Continued Review of Select Industrial Categories..................................7-1

7.2 New Data Sources and Additional Supporting Analyses ........................7-2

7.3 References for Results of the 2014 Annual Review ................................7-4
List of Tables

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LIST OF TABLES

Page

Table 4-1. Comments on the Preliminary 2014 Effluent Guidelines Program Plan EPA 

Docket Number: EPA-HQ-OW-2014-0170 .................................................................... 4-4

Table 5-1. Regulated Pollutants and ELG Limits for the Metal Finishing Category, 

Subpart A ......................................................................................................................... 5-5

Table 5-2. Unit Operations Regulated by ELGs for the Metal Finishing Category .................... 5-6

Table 5-3. Comparison of Maximum Monthly Average Effluent Limits Between Parts 

413 and 433 and the Proposed Limits for Part 438.......................................................... 5-8

Table 5-4. Estimated Number of Metal Finishing Facilities Identified During the MP&M 

Rulemaking Efforts.......................................................................................................... 5-9

Table 5-5. Number of Metal Finishing Facilities by Discharge Practice .................................. 5-14

Table 5-6. Water Use by Unit Operation................................................................................... 5-15

Table 5-7. Waste Characteristics by Unit Operation ................................................................. 5-16

Table 5-8. Metal Finishing Category Top 2011 DMR Pollutants ............................................. 5-18

Table 5-9. Metal Finishing Category Top 2011 TRI Pollutants................................................ 5-18

Table 5-10. Summary of Wastewater Treatment Technologies for End-of-Pipe Discharge 

of Metal Finishing Wastewater...................................................................................... 5-22

Table 5-11. Summary of Waste Minimization Technologies for Reuse ................................... 5-24

Table 5-12. Summary of Wastewater Treatment Technologies for Reuse of Metal 

Finishing Wastewater..................................................................................................... 5-26

Table 5-13. PAIs Measured by EPA-Approved Methods Without Limits in Subparts A 

and B of the Pesticide Chemicals ELGs (40 CFR Part 455).......................................... 5-35

Table 5-14. Registration Status for the 30 PAIs of Interest....................................................... 5-36

Table 5-15. Brick Manufacturing Facilities in the U.S.............................................................. 5-42

Table 5-16. Clay Ceramics Facilities in the U.S........................................................................ 5-44

Table 6-1. Common Types of Engineered Nanomaterials........................................................... 6-4

Table 6-2. Calculated Model Values for Predicted Environmental Concentrations of 

Engineered Nanomaterials in the U.S............................................................................ 6-10
List of Tables

LIST OF TABLES (Continued)

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vii

Table 6-3. Research Organizations Developing Analytical Methods for ENMs....................... 6-11

Table 6-4. Frequency of Industries Represented in IWTT ........................................................ 6-23

Table 6-5. List of Data Input Tables.......................................................................................... 6-24

Table 6-6. Overview of Information Captured in IWTT........................................................... 6-26

Table 6-7. Pilot- or Full- Scale Treatment Technologies Captured in IWTT............................ 6-27

Table 6-8. Industries with Performance data in IWTT.............................................................. 6-29

Table 6-9. Top Parameters with Performance Data in IWTT.................................................... 6-30
List of Figures

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LIST OF FIGURES

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Figure 2-1. Odd-Year Annual Review of Existing ELGs............................................................ 2-8

Figure 2-2. Odd-Year Identification of Possible New ELGs....................................................... 2-9

Figure 2-3. Even-Year Annual Review of Existing ELGs and Identification of Possible 

New ELGs...................................................................................................................... 2-10

Figure 2-4. Further Review of Industrial Categories Identified During Annual Reviews......... 2-11

Figure 5-1. Metal Finishing Process Application ...................................................................... 5-12

Figure 6-1. IWTT Structure ....................................................................................................... 6-26
I 

PART I: INTRODUCTION
Section 1—2014 Annual Review Executive Summary

1-1 

1. 2014 ANNUAL REVIEW EXECUTIVE SUMMARY

Effluent limitations guidelines and standards (ELGs) are an essential element of the 

nation’s clean water program, which was established by the 1972 Clean Water Act (CWA). 

ELGs are technology-based regulations used to control industrial wastewater discharges. EPA 

issues ELGs for new and existing point source categories that discharge directly to surface 

waters, as well as those that discharge indirectly to publicly-owned treatment works (POTWs). 

These ELGs are applied in discharge permits as limits to the pollutants that facilities may 

discharge. To date, EPA has established ELGs to regulate wastewater discharges from 58 point 

source categories. This regulatory program substantially reduces industrial wastewater pollution 

and continues to be a critical aspect of the effort to clean the nation's waters. 

In addition to developing new ELGs, the CWA requires EPA to revise existing ELGs 

when appropriate. Over the years, EPA has revised ELGs in response to developments such as 

advances in treatment technology and changes in industry processes. To continue its efforts to 

reduce industrial wastewater pollution and fulfill CWA requirements, EPA conducts an annual 

review and effluent guidelines planning process. The annual review and planning process has 

three main objectives: (1) to review existing ELGs to identify candidates for revision, (2) to 

identify new categories of direct dischargers for possible development of effluent guidelines, and 

(3) to identify new categories of indirect dischargers for possible development of pretreatment 

standards. To achieve these objectives, EPA conducts a two-phase review. First, EPA screens 

industrial discharges based on the relative hazard they pose to human health and the 

environment. Then, for those categories identified as a hazard priority, EPA conducts a more 

detailed evaluation to determine if the category is a candidate for new or revised ELGs. 

Beginning with the 2012 Annual Review, EPA began augmenting the methods and data 

sources it uses to identify industrial categories for which new or revised ELGs may be 

developed. This new approach combines the traditional toxicity rankings analysis (TRA) and the 

analyses of new hazard data sources not included in the TRA, coupled with an expanded review 

of new or improved treatment technologies. EPA performs these review efforts in alternate 

years—completing the TRA in odd years and the analyses of additional industrial hazard data 

sources and new treatment technologies in even years. The aim of the even-year review is to 

expand EPA’s ability to identify new pollutants of concern and to identify wastewater discharges

in industrial categories not currently regulated by ELGs. This review also enables EPA to screen 

industrial wastewater discharges based on a broader set of hazard data and to account for 

advances in treatment technologies much earlier in the review process. Both of these factors are 

keys to improving the effectiveness of the Effluent Guidelines Program. EPA has already 

completed its odd-year review for 2013 using the TRA and published the results in the 

Preliminary 2014 Effluent Guidelines Program Plan (Preliminary 2014 Plan) (79 FR 55472).1

 

For the 2014 Annual Review, EPA followed up on several proposed actions identified in 

the Preliminary 2014 Plan (79 FR 55472). Specifically, EPA continued the following reviews: 

(1) preliminary review of the Metal Finishing Point Source Category; (2) targeted review of 

 

1 The Preliminary 2014 Plan is combined with the Final 2012 Plan in the document Final 2012 and Preliminary 

2014 Effluent Guidelines Program Plans. The Plans discuss the findings of both the 2012 and 2013 Annual Reviews 

(79 FR 55472). 
Section 1—2014 Annual Review Executive Summary

1-2 

pesticide active ingredients (PAIs) for which the discharge from manufacturing is not currently 

regulated under the Pesticide Chemicals ELGs; and (3) review of the use of wet air pollution 

controls within the brick and structural clay products manufacturing industry. EPA also initiated 

an investigation of the manufacture and processing of engineered nanomaterials (ENMs) as a 

potential new source of industrial wastewater discharge; continued its review of industrial 

wastewater treatment technology data for the Industrial Wastewater Treatment Technology 

(IWTT) Database; and reviewed public comments submitted on the Preliminary 2014 Plan. For 

more information on the 2014 Annual Review analyses, see the bullets below. 

• Continued Review of the Metal Finishing Category (40 CFR Part 433). As a 

follow up to the findings in its 2012 and 2013 Annual Reviews, and in response to 

some public comments on the Preliminary 2012 Effluent Guidelines Program 

Plan, EPA continued its preliminary review of the Metal Finishing Category in 

the 2014 Annual Review. Specifically, EPA reviewed the scope of the existing 

ELGs, examined the current industry profile, and gathered data on wastewater 

treatment technologies. EPA also contacted regional EPA pretreatment 

coordinators to further discuss metal finishing operations and potential 

applicability issues associated with the Metal Finishing ELGs.

• Targeted Review of Pesticide Active Ingredients (PAIs) Without Pesticide 

Chemical Manufacturing Effluent Limits (40 CFR Part 455). As part of the 2012 

Annual Review, EPA reviewed analytical methods that it recently developed or 

revised to facilitate its identification of unregulated pollutants in industrial 

wastewater discharge. By examining these methods, EPA identified 30 PAIs that 

are now measured by existing analytical methods under 40 CFR Part 136, but that 

do not currently have pesticide chemicals manufacturing effluent limits under 

Subparts A and B in the Pesticide Chemicals ELGs (40 CFR Part 455) (U.S. 

EPA, 2014). For the 2014 Annual Review, EPA began evaluating data sources 

that would provide information on the production of the 30 PAIs of interest to 

identify and prioritize for further review any that are manufactured in the U.S. 

These sources included pesticide registration status under Section 3 of the Federal 

Insecticide, Fungicide, and Rodenticide Act (FIFRA) and production information 

reported under Section 7 of FIFRA. 

• Continued Review of Brick and Structural Clay Products Manufacturing. As part 

of EPA’s 2012 Annual Review, EPA identified brick and structural clay products 

manufacturing as an industry not currently regulated by ELGs that may have 

industrial wastewater discharges resulting from federal air pollution control 

requirements. For its 2014 Annual Review, EPA reviewed the current National 

Emission Standards for Hazardous Air Pollutants (NESHAP) for the industry, and 

contacted EPA’s Office of Air and Radiation and the Brick Industry Association 

to learn more about the NESHAP and the potential impacts on the industry, 

specifically regarding the installation of wet air pollution controls. 

• Review of Engineered Nanomaterials (ENMs) in Industrial Wastewater. EPA 

began evaluating ENMs as a potential emerging industrial wastewater pollutant 

category of concern as part of the 2014 Annual Review. EPA reviewed current 
Section 1—2014 Annual Review Executive Summary

1-3 

literature and communicated with leading researchers and government 

stakeholders about the fate, transport, and effects of ENMs on the environment 

and human health, and about the presence and discharge of ENMs in industrial 

wastewater. 

• Review of Industrial Wastewater Treatment Technologies. EPA continued 

reviewing technical papers and research articles regarding the performance of new 

and improved industrial wastewater treatment technologies and began populating 

the performance data and treatment information into a searchable IWTT

Database. As part of the 2014 Annual Review, EPA described its industrial 

wastewater treatment technology data collection methodology, data quality 

assurance and control, and database design, development, and storage. EPA also 

summarized the industrial wastewater treatment technology information collected 

to date.

Based on the data and analyses conducted for the 2014 Annual Reviews, and public 

comment and stakeholder input, EPA identified several outstanding data gaps and topics that 

warrant further investigation. These include: 

• New metal finishing processes, pollutants of concern, and advances in wastewater 

treatment technologies (see Section 5.1); 

• The production of PAIs of interest that do not have pesticide chemicals 

manufacturing limits under Subparts A and B of the Pesticides Chemicals ELGs, 

particularly for those PAIs that are not currently registered under FIFRA, but that 

may be produced in the U.S. for export only (see Section 5.2); and 

• ENMs, particularly silver, titanium dioxide, and carbon-based nanomaterials, as 

new potential pollutants of concern in industrial wastewater discharge (see 

Section 6.1). 

From the 2014 Annual Review, EPA determined that one industry, brick and structural 

clay products manufacturing, is not generating a potential new source of industrial wastewater 

discharge that warrants regulation at this time (see Section 5.3). 

As part of the 2014 Annual Review, EPA also compiled and presented the information 

collected to date in the IWTT Database from 163 articles, 98 of which provide both treatment 

system information and performance data. The treatment system performance data cover 142 

pollutant parameters and 35 different industries (see Section 6.2).

This report details EPA’s methodology for its 2014 Annual Review and supports EPA 

Office of Water’s Final 2014 Effluent Guidelines Program Plan (U.S. EPA, 2015). The Plan, 

pursuant to Section 304(m) of the Clean Water Act (CWA),2 discusses the findings of the 2014 

Annual Review and details EPA’s proposed actions and follow-up. The Plan also identifies any 

 

2 Available at: http://water.epa.gov/lawsregs/lawsguidance/cwa/304m/. 
Section 1—2014 Annual Review Executive Summary

1-4 

new or existing industrial categories selected for effluent guidelines rulemaking and provides a 

schedule for such rulemaking.

1.1 References for 2014 Annual Review Executive Summary 

1. U.S. EPA. 2014. The 2012 Annual Effluent Guidelines Review Report. Washington, D.C. 

(September). EPA-821-R-14-004. EPA-HQ-OW-2010-0824-0320. 

2. U.S. EPA, 2015. Final 2014 Effluent Guidelines Program Plan. Washington, D.C. (July). 

EPA-821-R-15-002. EPA-HQ-OW-2014-0170. DCN 08107. 
Section 2—Background

2-1 

2. BACKGROUND

This section explains how the Effluent Guidelines Program fits into EPA’s National

Water Program, describes the general and legal background of the Effluent Guidelines Program, 

and summarizes EPA’s process for making effluent guidelines revision and development 

decisions (i.e., effluent guidelines planning), including details of its annual review process. 

2.1 The Clean Water Act and the Effluent Guidelines Program

The Clean Water Act (CWA) is based on the principle of cooperative federalism, with 

distinct roles for both EPA and the states, in which the goal is to restore and maintain the 

chemical, physical, and biological integrity of the nation’s waters. To that end, the Act is 

generally focused on two types of controls: (1) water-quality-based controls, based on water 

quality standards, and (2) technology-based controls, based on effluent limitations guidelines and 

standards (ELGs). 

The CWA gives states the primary responsibility for establishing, reviewing, and revising 

water quality standards. Water quality standards consist of designated uses for each water body 

(e.g., fishing, swimming, supporting aquatic life), criteria that protect the designated uses 

(numeric pollutant concentration limits and narrative criteria, for example, “no objectionable 

sediment deposits”), and an antidegradation policy. EPA develops recommended national criteria 

for many pollutants, pursuant to CWA section 304(a), 33 U.S.C. § 1314(a), which states may 

adopt or modify, as appropriate, to reflect local conditions. 

EPA is responsible for developing technology-based ELGs, based on currently available 

technologies, for controlling industrial wastewater discharges. ELGs apply to pollutant 

discharges from industrial facilities directly to surface water (direct discharges) and to publicly 

owned treatment works (POTWs) (indirect discharges). For sources discharging directly to 

surface waters, permitting authorities—states authorized to administer the National Pollutant 

Discharge Elimination System (NPDES) permit program, and EPA in the few states that are not 

authorized— must incorporate EPA-promulgated limitations and standards into discharge 

permits, where applicable (U.S. EPA, 2010). Categorical pretreatment standards are directly 

enforceable.

While technology-based effluent limitations and standards in discharge permits are 

sometimes as stringent as, or more stringent than necessary to meet water quality standards, the 

effluent guidelines program is not specifically designed to ensure that the discharges from each 

facility meet the water quality standards of the receiving water body. For this reason, the CWA 

also requires authorized states to establish water-quality-based effluent limitations where 

necessary to meet water quality standards. Water-quality-based limits may require industrial 

facilities to meet requirements that are more stringent than those of a national effluent guideline 

regulation. In the overall context of the CWA, ELGs must be viewed as one tool in the broader 

set of tools and authorities Congress provided to EPA and the states to restore and maintain the 

quality of the nation’s waters. 

The 1972 amendments to the CWA marked a distinct change in Congress’s efforts “to 

restore and maintain the chemical, physical, and biological integrity of the Nation’s waters” (see 
Section 2—Background

2-2 

CWA section 101(a), 33 U.S.C. 1251(a)). Before 1972, the CWA focused principally on water 

quality standards. This approach was challenging, however, because of the difficulty in

determining whether a specific discharger, or combination of dischargers, was responsible for 

decreasing the water quality in a receiving stream.

The 1972 CWA directed EPA to promulgate effluent limitations guidelines and standards 

that reflect pollutant reductions achievable by categories or subcategories of industrial point 

sources through the implementation of available treatment and prevention technologies. The 

ELGs are based on specific technologies (including process changes) that EPA identifies as 

meeting the statutorily prescribed level of control (see CWA sections 301(b)(2), 304(b), 306, 

307(b), and 307(c)). See Appendix A of this report for more information on the CWA and an 

explanation of the different levels of control for ELGs. 

Unlike other CWA tools, ELGs are national in scope and establish pollution control 

obligations for all facilities that discharge wastewater within an industrial category or 

subcategory. In establishing these controls under the direction of the statute, EPA assesses, for 

example: (1) the performance and availability of the best pollution-control technologies or 

pollution-prevention practices for an industrial category or subcategory as a whole; (2) the 

economic achievability of those technologies, which can include consideration of the 

affordability of achieving the reduction in pollutant discharge; (3) the cost of achieving effluent 

reductions; (4) non-water-quality environmental impacts (including energy requirements); and 

(5) such other factors as the EPA Administrator deems appropriate. 

In passing the CWA, congress viewed the creation of a single national pollution control 

requirement for each industrial category, based on the best technology the industry can afford, as 

a way to reduce the potential creation of “pollution havens” and set the nation’s sights on 

eliminating pollutant discharge to U.S. waters. Consequently, EPA’s goal in establishing national 

ELGs is to ensure that industrial facilities with similar characteristics, regardless of their location 

or the nature of their receiving water, will, at a minimum, meet similar effluent limitations and 

standards representing the performance of the best pollution control technologies or pollution 

prevention practices. 

ELGs provide the opportunity to promote pollution prevention and water conservation. 

This may be particularly important in controlling persistent, bioaccumulative, and toxic 

pollutants discharged in concentrations below analytic detection levels. 

2.2 Effluent Guidelines Review and Planning Process

In addition to establishing new regulations, the CWA requires EPA to review existing 

effluent guidelines annually. EPA reviews all point source categories subject to existing effluent 

guidelines and pretreatment standards to identify potential candidates for revision, consistent 

with CWA sections 304(b), 301(d), 304(m)(1)(A) and 304(g). EPA also reviews industries 

consisting of direct-discharging facilities not currently subject to effluent guidelines to identify 

potential candidates for effluent guidelines rulemakings, pursuant to CWA section 304(m)(1)(B). 

Finally, EPA reviews industries consisting entirely or almost entirely of indirect-discharging 

facilities that are not currently subject to pretreatment standards, to identify potential candidates 

for pretreatment standards development under CWA section 307(b). 
Section 2—Background

2-3 

2.2.1 Effluent Guidelines Review and Prioritization Factors

In its annual reviews, EPA considers four major factors to prioritize existing effluent 

guidelines or pretreatment standards for possible revision, or to identify new industries of 

concern through alternate analyses. These factors were developed in EPA’s draft National 

Strategy, described at http://water.epa.gov/scitech/wastetech/guide/strategy/fs.cfm. 

The first factor EPA considers is the amount and type of pollutants in an industrial 

category’s discharge and the relative hazard posed by that discharge. Using this factor enables 

EPA to prioritize rulemakings to achieve significant environmental and health benefits. 

The second factor EPA considers is the performance and cost of applicable and 

demonstrated wastewater treatment technologies, process changes, or pollution prevention 

alternatives that could effectively reduce pollutant concentrations in the industrial category’s 

wastewater and, consequently, reduce the hazard posed by these pollutant discharges to human 

health or the environment. 

The third factor EPA considers is the affordability or economic achievability of the 

wastewater treatment technology, process change, or pollution prevention measures identified 

using the second factor. If the financial condition of the industry indicates that it would not be 

affordable to implement expensive and stringent new requirements, EPA might conclude a less 

stringent, less expensive approach to reduce pollutant loadings would better satisfy applicable 

statutory requirements.

The fourth factor EPA considers is the opportunity to eliminate inefficiencies or 

impediments to pollution prevention or technological innovation, or opportunities to promote 

innovative approaches such as water-quality trading, including within-plant trading. This factor 

might also prompt EPA, during annual reviews, to decide against revising an existing set of 

effluent guidelines or pretreatment standards where the pollutant source is already efficiently and 

effectively controlled by other regulatory or non-regulatory programs.

2.2.2 Annual Review Process

EPA’s annual review process includes an odd- and even-year annual review cycle, to 

address cohesively and comprehensively the factors laid out in EPA’s draft National Strategy. In 

the odd-year reviews, EPA screens industrial dischargers through a toxicity ranking analysis 

(TRA) that identifies and ranks those categories whose reported pollutant discharges pose a 

substantial hazard to human health and the environment (the first draft National Strategy factor). 

For the TRA, EPA relies on discharge monitoring report (DMR) and Toxics Release Inventory 

(TRI) data to rank industrial discharge categories based on toxic-weighted pound equivalents 

(TWPE) released. EPA relies on facility and state contacts, permits, and publicly available data 

sources to review top ranking industrial categories (see Section 2.2.2.1 for more detail on the 

TRA).

In the even years, EPA reviews additional hazard data sources and conducts alternate 

analyses to enhance the identification of industrial categories for which new or revised ELGs 

may be appropriate, beyond those that traditionally rank high in the TRA. This is consistent with 

the Government Accountability Office’s (GAO) recommendation that EPA’s annual review 
Section 2—Background

2-4 

approach include additional industrial hazard data sources to augment its screening-level review 

of discharges from industrial categories.3 Furthermore, EPA recognizes the need to consider, in 

the screening phase, the availability of treatment technologies, process changes, or pollution 

prevention practices that can reduce the identified hazards (the second and fourth draft National 

Strategy factors). Specifically, in the even-year reviews, EPA is targeting new data sources that 

will provide information on other considerations not previously captured as part of the TRA, 

including, but not limited to, the following: 

• Industrial process changes;

• Emerging contaminants of concern;

• Advances in treatment technologies and pollution prevention practices; 

• Availability of new, more sensitive analytical methods; and

• Other hazard data and information not captured in the TRA and/or suggested by 

stakeholders or by public comments. 

Using the TRA in the odd-year review in conjunction with additional analyses and hazard 

data in the even-year review, EPA is considering more cohesively and comprehensively the 

factors laid out in EPA’s draft National Strategy. This approach allows the Agency to prioritize 

existing effluent guidelines or pretreatment standards for possible revision, or identify new 

industries of concern through alternate analyses. See Section 2.2.2.2 for an overview of EPA’s 

even-year analyses.

EPA also conducts a more detailed preliminary category review of those industrial 

discharge categories that rank highest in terms of TWPE (i.e., pose the greatest hazard to human 

health and the environment) in the TRA, or are identified as warranting further review during the 

even-year analyses. If EPA determines that further review is appropriate for an industrial 

category, EPA may complete a preliminary or detailed study of the point source category (see 

Section 2.2.2.3 and Section 2.2.2.4, respectively), which may eventually lead to a new or revised 

guideline. 

2.2.2.1 Overview of the Toxicity Ranking Analysis and Odd-Year Annual Reviews

In the odd-year annual reviews, EPA conducts a TRA using data from the TRI and data 

from DMRs contained in the Permit Compliance System (PCS) and the Integrated Compliance 

Information System for the National Pollutant Discharge Elimination System (ICIS-NPDES). 

Figure 2-1 details how EPA uses the TRA to identify existing ELGs that may warrant revision. 

Figure 2-2 addresses how EPA identifies new categories that may warrant regulation. 

TRI and DMR data do not identify the effluent guideline(s) applicable to a particular 

facility. However, TRI includes information on a facility’s North American Industry 

Classification System (NAICS) code, while DMR data include information on a facility’s 

Standard Industrial Classification (SIC) code. Thus, the first step in EPA’s TRA is to relate each 

 

3 GAO’s recommendations for the review of additional hazard data sources were published in GAO’s September 

2012 report, Water Pollution: EPA Has Improved Its Review of Effluent Guidelines but Could Benefit from More 

Information on Treatment Technologies, available online at http://www.gao.gov/assets/650/647992.pdf. 
Section 2—Background

2-5 

SIC and NAICS code to an industrial category.4 The second step is to use the information 

reported in TRI and DMR for a specific year to calculate the pounds of pollutant discharge to 

U.S. waters. These calculations are performed for toxic, nonconventional, and conventional 

pollutants. For indirect dischargers, EPA adjusts the facility discharges to account for removals 

at the POTW. The third step is to apply toxic weighting factors (TWFs)5 to the annual pollutant 

discharges to calculate the total discharge of toxic pollutants as TWPE for each facility. EPA 

then sums the TWPE for each facility in a category to calculate a total TWPE per category for 

that year. EPA calculates two TWPE estimates for each category: (1) an estimate based on data 

in TRI and (2) an estimate based on DMR data. EPA combines these two estimates to generate a 

single TWPE value for each industrial category. EPA takes this approach because it found that 

combining the TWPE estimates from TRI and DMR data into a single TWPE number offered a 

clearer perspective of the industries with the most toxic pollution.6

EPA then ranks point source categories according to their total TWPE discharges. To 

identify categories for further review, EPA prioritizes categories accounting for 95 percent of the 

cumulative TWPE from the combined DMR and TRI data. For more information on EPA’s oddyear review process and methodology, see Section 3 of EPA’s Preliminary 2012 Effluent 

Guidelines Program Plan (U.S. EPA, 2013). 

As illustrated in Figure 2-1, EPA typically excludes from further review categories for 

which an effluent guidelines rulemaking is currently underway, or for which effluent guidelines 

have been promulgated or revised within the past seven years.

7 EPA also excludes categories in 

which only a few facilities account for a large majority of toxic-weighted pollutant discharges. 

EPA generally does not prioritize such a category for additional review, but suggests that 

individual permits may be more effective in addressing the toxic-weighted pollutant discharges 

than a national effluent guidelines rulemaking. For more information on the results of the 2013 

Annual Review, see Section 6 of EPA’s 2013 Annual Effluent Guidelines Review Report (U.S. 

EPA, 2014). 

As illustrated in Figure 2-2, EPA may also evaluate discharges in the odd-year TRA that 

are associated with SIC or NAICS codes that are not currently regulated or that may be a 

potential new subcategory of an existing ELG. EPA evaluates these discharges to determine if 

new ELGs are warranted for the new industrial category or subcategory. Similarly, EPA can 

supplement this information with findings from new analyses conducted in the even-year annual 

 

4 For more information on how EPA related each SIC and NAICS code to an industrial category, see Section 5.0 of 

the 2009 Technical Support Document for the Annual Review of Existing Effluent Guidelines and Identification of 

Potential New Point Source Categories (U.S. EPA, 2009).

5 For more information on TWFs, see Toxic Weighting Factor Development in Support of CWA 304(m) Planning 

Process (U.S. EPA, 2006).

6 Different pollutants may dominate the TRI and DMR TWPE estimates for an industrial category due to the 

differences in pollutant reporting requirements between the TRI and DMR databases. The single TWPE number for 

each category highlights those industries with the most toxic discharge data in both TRI and DMR. Although this 

approach could have theoretically led to double-counting, EPA's review of the data indicates that, because the two 

databases focus on different pollutants, double-counting is minimal and does not affect the order of the top-ranked 

industrial categories.

7 EPA chose seven years because this is the typical length of time for the effects of effluent guidelines or 

pretreatment standards to be fully reflected in pollutant loading data and TRI reports.
Section 2—Background

2-6 

review, as well as review of treatment technology performance data, to identify new industrial 

categories that may warrant ELGs (see Section 2.2.2.2).

2.2.2.2 Overview of Even-Year Annual Reviews

In the even-year annual reviews, EPA identifies additional hazard data and reviews 

treatment technologies to augment the TRA completed in each odd-year review. EPA prioritizes 

the review of these additional hazard data sources based on three factors: (1) the likelihood of 

identifying unregulated industrial discharges, (2) the utility of identifying new wastewater 

treatment technologies or pollution prevention alternatives, and (3) representativeness of the data 

for an industrial category. These new analyses take into account a broader set of hazard data and 

advancements in treatment technologies. In addition to the new hazard data sources, the evenyear reviews will include information from the public comments received on the Preliminary 

Plan and any continuing preliminary category reviews identified during the odd-year review, as 

illustrated in Figure 2-3. The specific methodologies and analyses of EPA’s 2014 Annual 

Review are described in more detail in Part II of this report. 

2.2.2.3 Preliminary Category Reviews

EPA may complete preliminary category reviews as part of the annual review cycle, 

depending on the industrial categories warranting review at that time. EPA may conduct a 

preliminary category review for the industrial categories with the highest hazard potential 

identified in the TRA, or identified as a priority from any of the even-year review analyses, 

particularly if it lacks sufficient data to determine whether regulatory action would be 

appropriate, as illustrated in Figure 2-4. In its preliminary category reviews, EPA typically 

examines the following: (1) wastewater characteristics and pollutant sources, (2) the pollutants 

driving the toxic-weighted pollutant discharges, (3) availability of pollution prevention and 

treatment, (4) the geographic distribution of facilities in the industry, (5) any pollutant discharge 

trends within the industry, and (6) any relevant economic factors. 

In executing preliminary category reviews, EPA first attempts to verify the toxicity 

ranking results and fill in data gaps. These assessments provide an additional level of quality 

assurance for the reported pollutant discharges and number of facilities that represent the 

majority of toxic-weighted pollutant discharge. After the ranking results are verified, EPA next 

considers costs and performance of applicable and demonstrated technologies, process changes, 

or pollution prevention alternatives that can effectively reduce the pollutants in the point source 

category’s wastewater. Finally, and if appropriate based on the other findings, EPA considers the 

affordability or economic achievability of the technology, process change, or pollution 

prevention measure identified using the second factor. 

During a preliminary category review, EPA may consult data sources including, but not 

limited to the following: (1) the U.S. Economic Census, (2) TRI and DMR data, (3) trade 

associations and reporting facilities that can verify reported releases and facility categorization, 

(4) regulatory authorities (states and EPA regions) that can clarify how category facilities are 

permitted, (5) NPDES permits and their supporting fact sheets, (6) EPA effluent guidelines 

technical development documents, (7) relevant EPA preliminary data summaries or study 

reports, and (8) technical literature on pollutant sources and control technologies. If a 
Section 2—Background

2-7 

preliminary category review reveals that the reports of toxic discharges are correct, not 

geographically isolated, and likely to be the result of the production practices in use broadly 

throughout the category, EPA may decide to conduct a preliminary or detailed study prior to 

initiating a rulemaking. In many cases, the information and data gathered for a study forms the 

basis of information used for the rulemaking. However, in some instances, EPA may decide not 

to move forward with a rulemaking following a study, if the data and information gathered 

indicates that a new or revised guideline is not warranted. Regardless of the outcome, EPA 

announces to the public and other stakeholders decisions to conduct studies, or to develop 

rulemakings, in the Effluent Guidelines Program Plan. When a rulemaking is determined 

appropriate, schedules are also announced in the Plan. 

2.2.2.4 Preliminary and Detailed Studies 

After conducting the preliminary category reviews, as shown in Figure 2-4, EPA may 

then conduct either a preliminary or detailed study of an industrial category. Typically, these 

studies profile an industry category, gather information about the hazards posed by its 

wastewater discharges, collect information about availability and cost of treatment and pollution 

prevention technologies, assess the financial status of the facilities in the category, and 

investigate other factors to determine if it would be appropriate to identify the category for 

possible effluent guidelines revision. During preliminary or detailed studies, EPA typically 

examines the factors and data sources listed above for preliminary category reviews. However, 

during a detailed study EPA’s examination of a point source category and available pollution 

prevention and treatment options is generally more rigorous than the analysis conducted during a 

preliminary category review or study, and may include primary data collection activities (such 

as industry questionnaires and wastewater sampling and analysis) to fill data gaps. 
Section 2—Background

2-8 

* If EPA is aware of new segment growth within such a category or new concerns are identified, EPA may do 

further review.

Figure 2-1. Odd-Year Annual Review of Existing ELGs

Begin odd-year review

of existing ELGs

Identify 

applicable SIC 

and NAICS 

codes for each 

point source 

category

Preliminary results of Toxicity Rankings Analysis

= Combined TRIReleases and DMRLoads

database rankings (Factor 1)

DMR & TRI

database 

tools

Stakeholder 

recommendations 

and comments

Are ELG revisions 

currently 

underway?

Have 

ELGs been 

developed or revised 

within the past 7 

years?

Are 

non-representative 

facilities responsible for 

overall category

TWPE?

When ranked 

by TWPE, does category 

contribute to top 95% of 

cumulative TWPE of all 

categories?

Are there 

identified implementation

and efficiency 

issues (Factor 4)?

Not a priority

category, no 

further

review at this time

Not a priority

category, no further

review at this time* 

Not a priority 

category,

but may recommend 

permitting support

for individual facilities

Further review

(see Figure 2-4)

Possible outcomes

-Further review

-BPJ support

-Identify for 

possible

revision of existing 

ELGs

-No action

Stakeholder recommendations and comments

Not a priority category,

no further review at this time

No

No

No

No

No

Yes

Yes

Yes

Yes

Yes

Evaluation of treatment technology performance data
Section 2—Background

2-9 

* Significant concentrations include levels above minimum levels from 40 CFR Part 136 or other EPA-approved 

methods, levels above treatability levels, or at levels of concern to human health and toxicity.

Figure 2-2. Odd-Year Identification of Possible New ELGs 

Stakeholder recommendations

and comments

Begin industry

identification

TRA databases

No identification or

further review necessary

Identify SIC/NAICS codes

with discharges not subject

to existing ELGs

Is the SIC/NAICS code 

appropriately considered a 

potential new subcategory

of an existing ELG?

Is the possible new

category all or nearly all

indirect dischargers?

Include in annual review 

of

existing category

(see Figure 2-1)

Are pollutants

potentially present at

significant 

concentrations?*

No identification or

further review 

necessary

Do 

discharges interfere

with or otherwise pass

through POTW

operations?

Further review

(see Figure 2-4)

Identify other tools

(e.g. permit-based

support or guidance)

Are ELGs the 

appropriate tool?

No

No

No

Yes No No

Yes

Yes Yes

Yes
Section 2—Background

2-10 

* Significant concentrations include levels above minimum levels from 40 CFR Part 136 or other EPA-approved 

methods, levels above treatability levels, or at levels of concern to human health and toxicity.

Figure 2-3. Even-Year Annual Review of Existing ELGs and Identification of 

Possible New ELGs

Begin even-year review

of hazard data sources and 

treatment technology 

performance data

Identify industries with 

pollutant

discharges not previously 

reviewed

Determine if an 

existing industry point source

category is applicable

to discharges

Stakeholder

recommendations

and comments

Continued review from 

odd-year (as necessary)

Collect additional data from

industry groups, published

reports from EPA, and peerreviewed publications

Are pollutants

potentially present at

significant

concentrations?*

Not a priority

category, no 

further

review at this time

Further review

(see Figure 2-4)

Do ELGs 

appropriately

regulate all pollutant

discharges identified?

Not a priority

category, no further

review at this time

No

No

No

Yes

Yes

Yes
Section 2—Background

2-11 

Figure 2-4. Further Review of Industrial Categories Identified During Annual Reviews

Category identified for further 

review (see Figures 2-1, 2-2, and 2-3)

Further Review

- Preliminary category 

review

- Preliminary or detailed 

study

(continue collecting data 

covering all four factors)

Are discharges

adequately controlled

by existing ELGs?

No further review at this time

Are ELGs potentially 

the appropriate tool?

Identify for possible 

promulgation or revision 

of ELGs

Identify other tools (e. g., 

permit-based support or guidance)

Not enough

information

Stakeholder 

input

Yes

No

Yes

No

2.2.3 Effluent Guidelines Program Plans

CWA section 304(m)(1)(A) requires EPA to publish an Effluent Guidelines Program 

Plan (Plan) every two years that establishes a schedule for the annual review and revision, in 

accordance with section 304(b), of the effluent limitations guidelines that EPA has promulgated 

under that section. EPA publishes the results of the TRA and preliminary category review 

conducted during the odd-year review in a Preliminary Plan, and takes public comment. In the 

even year following publication of the Preliminary Plan, EPA identifies and evaluates additional 

data sources and hazard analyses to supplement the TRA. EPA then publishes a Final Plan in the 

even year. The Final Plan presents the compilation of the odd- and even-year reviews and any 

public comments received on the Preliminary Plan. EPA may initiate, continue, or complete 

preliminary category reviews or in-depth studies during the odd- or even-year reviews, 

depending upon when it identifies a category warranting further review. Additionally, EPA may 
Section 2—Background

2-12

publish the findings from these studies as part of the Preliminary Plan or Final Plan, based on 

when during the planning cycle the study or review is completed. 

EPA has several reasons for coordinating its annual reviews under section 304(b) with 

publication of Plans under section 304(m). First, the annual reviews are inextricably linked to the 

planning effort because each review year’s results may inform the content of the Preliminary and 

Final Plans (e.g., by identifying candidates for effluent guidelines revision, or by identifying

point source categories for which EPA has never promulgated effluent limitations guidelines). 

Second, even though it is not required to do so under either section 304(b) or section 304(m), 

EPA believes it can serve the public interest by periodically describing the annual reviews 

(including the review process used) and review results to the public. Doing so while 

simultaneously publishing the Preliminary and Final Plans makes both processes more 

transparent. Third, by requiring EPA to review existing effluent limitations guidelines each year, 

Congress appears to have intended for each successive review to build on the results of earlier 

reviews. 

2.3 References for Background

1. U.S. EPA. 2010. U.S. EPA NPDES Permit Writers’ Manual. Washington, D.C.

(September). Available online at:

http://cfpub.epa.gov/npdes/writermanual.cfm?program_id=45. EPA-833-K-10-001. EPAHQ-OW-2010-0824-0236.

2. U.S. EPA. 2013. Preliminary 2012 Effluent Guidelines Program Plan. Washington, D.C.

(May). EPA-821-R-12-002. EPA-HQ-OW-2010-0824-0194.

3. U.S. EPA. 2014. The 2013 Annual Effluent Guidelines Review Report. Washington, D.C.

(September). EPA-821-R-12-003. EPA-HQ-OW-2014-0170-0077.
II

PART II: EPA’S 2014 ANNUAL

REVIEW METHOLOLOGY AND 

ANALYSES
Section 3—Introduction to EPA’s 2014 Annual Review

3-1

3. INTRODUCTION TO EPA’S 2014 ANNUAL REVIEW

The even-year review provides EPA with an opportunity to identify additional available 

hazard data sources and conduct further analyses at the pollutant, industry, or wastewater 

treatment technology levels. As described above in Section 2.2.2.2, EPA identified and 

prioritized additional data sources and analyses for the 2014 Annual Review based on (1) the 

likelihood that they would assist in identifying unregulated industrial discharges, (2) their utility 

in identifying new wastewater treatment technologies or pollution prevention alternatives, and 

(3) how well the data represent the activity of an industrial category.

EPA is using the data sources and analyses identified in this 2014 Annual Review to 

screen additional industrial discharge categories and pollutants of concern and to identify for 

further review those that potentially pose a hazard to human health or the environment. The 2014 

Annual Review consisted of three components: 

• Consideration of public comments on the Preliminary 2014 Effluent Guidelines 

Program Plan and other stakeholder input (see Section 4).

• Continuation of the industrial category reviews (e.g., collecting additional data, 

contacting permit writers, evaluating available treatment technology information) 

of specific industrial categories that EPA identified as warranting additional 

review in the Final 2012 and Preliminary 2014 Plan Effluent Guidelines Program 

Plans (see Section 5). 

• Identification and evaluation of new industrial hazard data sources and analyses 

of these data to identify new wastewater discharges or pollutants not previously 

regulated and to identify wastewater discharges that can be more effectively 

treated or eliminated (see Section 6).

The specific data sources, analyses, and findings for each of the 2014 Annual Review 

components listed above are described in detail in Sections 4, 5, and 6. A summary of the 2014 

Annual Review findings is presented in Part III of this report. 
Section 4—Public Comments and Other Stakeholder Input on 

the Final 2012 and Preliminary 2014 Effluent Guidelines Program Plans

4-1

4. PUBLIC COMMENTS AND OTHER STAKEHOLDER INPUT ON THE FINAL 2012 AND 

PRELIMINARY 2014 EFFLUENT GUIDELINES PROGRAM PLANS 

EPA’s annual review process considers information provided by the public and other 

stakeholders regarding the need for new or revised effluent limitations guidelines and 

pretreatment standards. Public comments received on EPA’s prior reviews and pans helped the 

Agency prioritize its analysis of existing effluent guidelines and pretreatment standards. This 

section presents a summary of the public comments and stakeholder input received on the 

Preliminary 2014 Effluent Guidelines Program Plan (Preliminary 2014 Plan). 

4.1 Public Comments and Stakeholder Input

EPA published its Preliminary 2014 Plan together with the Final 2012 Plan and provided 

a 60-day public comment period on the Preliminary 2014 Plan starting on September 16, 2014 

(see 79 FRN 55472). The Docket supporting the Final 2014 Effluent Guidelines Program Plan 

(Final 2014 Plan) includes a complete set of the comments submitted, as well as the Agency’s 

responses (see DCN 08110). EPA received comments on the Preliminary 2014 Plan from 18 

organizations; Table 4-1 presents a summary of these comments. 

Commenting organizations representing industry included: 

• American Petroleum Institute; 

• Coalbed Methane Association of Alabama; 

• American Forest & Paper Association; 

• National Association for Surface Finishing; 

• American Chemistry Council Nanotechnology Panel; 

• American Fuel & Petrochemical Manufacturers; 

• Valero Companies; 

• Greenway Products, Inc.; and

• NORA: an Association of Responsible Recyclers. 

Commenting organizations representing environmental groups included:8 

• Clean Water Action; 

• Earthjustice; 

• Earthworks; 

• Environmental Defense Fund; 

• League of Conservation Voters; 

• Natural Resources Defense Fund; and

• Sierra Club. 

 

8 Seven environmental organizations submitted one combined public comment on the Preliminary 2014 Plan. One of 

the environmental organizations also submitted a separate public comment on the Preliminary 2014 Plan.
Section 4—Public Comments and Other Stakeholder Input on 

the Final 2012 and Preliminary 2014 Effluent Guidelines Program Plans

4-2

Additionally, one consultant to pretreatment programs for local governments, CWA 

Consulting Services, LLC and one state representing organization, the Association of Clean 

Water Administrators (ACWA).

EPA received five comments on its proposed CWTs detailed study from one consultant 

to local government pretreatment programs, two industry representatives, and several 

environmental organizations. The consultant to local government pretreatment programs 

commented that EPA should review and clearly define the applicability of CWT effluent 

limitations guidelines and standards (40 CFR Part 437) as they relate to accepting oil and natural 

gas produced wastewater. One industry representative questioned the intent and basis for the 

CWTs detailed study, citing a lack of definition for what qualifies as a CWT, a lack of a 

reasonable basis for initiating the study, and potential overlap with the Oil and Gas Extraction 

ELGs for shale gas facilities that direct their wastewater to CWTs. The other industry 

representative commented that revising the CWT ELG may not be necessary to address 

discharges of oil and gas extraction wastewater (to CWTs, POTWs, or surface water) and that 

any new regulations and/or guidelines for CWT facilities could be aided by direct meetings 

between EPA, industry experts in the field, and the operators of CWT facilities. 

The environmental organizations supported EPA’s decision to undertake a detailed study 

of CWTs that accept oil and gas wastewaters and requested the study be expedited, citing that (1) 

the CWT ELGs are out of date in light of the developments in the oil and gas extraction industry; 

(2) CWTs may not have treatments in place for pollutants in oil and gas wastewaters; (3) oil and 

gas wastewaters may have potential impacts on drinking water sources; and (4) pretreatment 

standards under development for discharges to POTWs from onshore unconventional oil and gas 

extraction could result in more discharges to CWTs. One environmental organization also 

provided recommendations for resources and information in support of the CWT detailed study. 

For the Petroleum Refining Category (40 CFR Part 419), EPA received three comments 

from industry representatives questioning the quality and appropriateness of data used as the 

basis for initiating the study. Industry representatives also questioned EPA’s objective for 

examining feedstock metals. One industry representative questioned the basis for EPA’s 

investigation of polynuclear aromatic hydrocarbons. EPA also received a comment from the 

consultant to local government pretreatment programs supporting the detailed study and 

suggesting that EPA specifically evaluate common problem pollutants, including benzene and 

sulfides. In addition the commenter indicated that EPA should evaluate groundwater pump-andtreat operations to clearly define regulated, unregulated, and dilute waste streams.

EPA received comments on its proposed continued preliminary review of the Metal 

Finishing Category (40 CFR Part 433) from the consultant to local government pretreatment 

programs, one industry representative, and an organization representing states. The consultant to 

the local government pretreatment programs did not support reopening the regulation because it 

could make the regulation vulnerable to weakening by special interest groups. The industry 

representative did not support further review of the Metal Finishing Category, stating that EPA 

recently reviewed the industry as part of the Metal Products and Machinery ELGs rulemaking 

and determined that revised guidelines were not necessary. Further, the industry representative 

commented that the industry is not using new processes or treatment technologies that would

suggest the need to revise the applicable Metal Finishing ELGs, and POTWs have the ability to 
Section 4—Public Comments and Other Stakeholder Input on 

the Final 2012 and Preliminary 2014 Effluent Guidelines Program Plans

4-3

impose stricter limits to address specific concerns. The organization representing states 

supported further review of the Metal Finishing Category, stating that the industry has changed 

significantly since the existing regulations were developed. These changes include updated 

chemical formulas and processes, new pollutants of concern, new treatment technologies, and a 

broader scope for the metal finishing universe. The organization representing states also 

commented that clarification is needed regarding classification of a facility as an existing or new 

source, that there are inconsistencies in categorical determinations across the country for certain 

metal finishing applications (etching vs. cleaning, coating vs. adsorption, phosphate coating vs. 

cleaning), and that EPA should consider adopting a sunset provision for the Electroplating ELGs 

(40 CFR Part 413) to require eventual compliance with the Metal Finishing ELGs (40 CFR Part 

433). 

For nanomaterials, the consultant to local government pretreatment programs and one 

industry representative supported EPA’s effort to characterize nanomaterials in industrial 

wastewater discharges. Specifically, the industry representative urged EPA to recognize the 

diversity of nanomaterials and their applications across multiple industries in its future reports; 

coordinate closely with EPA’s New Chemicals Program to understand nanomaterial releases in 

water; consider work on the fate and transport of nanomaterials completed or currently 

underway; and recognize the potential for nanotechnology to provide new and improved tools for 

wastewater treatment. One wastewater treatment products manufacturer also commented that he 

is currently testing a coagulant/flocculent/filter aid that has shown success at settling nanoparticles, E. coli, phosphorus and other particulates. 

The group of seven environmental groups commented that ongoing revisions to 

pretreatment standards for discharges to POTWs need to reflect changes in onshore oil and gas 

exploration, stimulation, and extraction. One environmental organization commented that the oil 

and gas ELG rulemaking for the unconventional oil and gas facilities be finalized as soon as 

possible, and provided recommendations for resources and information in support of the 

rulemaking. 

The organization representing states supported EPA’s new even-year review 

methodology, used in the 2012 Annual Review, as well as inclusion of the current status of ELGs 

under development in the Final 2012 Plan. This commenter also suggested improvements to the 

ELG review and planning processes, including an increase in EPA staff allocated to work on 

ELGs and pretreatment standards, and publication of Annual Review Reports earlier in the 

planning process, as well as more timely publication of future ELG Plans. 

The consultant to local government pretreatment programs commented that EPA should 

add biodiesel manufacturing to the list of industrial sectors to evaluate. 

Lastly, EPA received three unsolicited comments on final decisions announced in the 

Final 2012 Plan. EPA did not solicit public comment on the content of the Final 2012 Plan since 

public comments were solicited on the actions and decisions when they were proposed in the 

Preliminary 2012 Plan on August 7, 2013. Regardless, one industry commenter indicated 

support for EPA’s decision in the Final 2012 Plan to delist coalbed methane as a new 

subcategory under the Oil and Gas Extraction Category (40 CFR Part 435), and an 

environmental organization indicated they did not support EPA’s decision to delist coalbed 
Section 4—Public Comments and Other Stakeholder Input on 

the Final 2012 and Preliminary 2014 Effluent Guidelines Program Plans

4-4

methane. The third unsolicited comment by an industry organization indicated support for 

EPA’s final decision in the Final 2012 Plan not to further review Pulp and Paper industry 

discharges. 

In general, the public comments submitted on the Preliminary 2014 Plan did not result in 

any new direction or determinations with respect to the proposed actions announced in the 

Preliminary 2014 Plan, or EPA’s final decisions and actions indicated in this Final 2014 Plan. 

EPA did, however, receive useful information and input from the public review that will help 

inform ongoing studies, in particular Petroleum Refining, Metal Finishing and CWTs. EPA’s 

responses to the specific comments can be found in EPA’s comment response document (DCN 

08110). 

Table 4-1. Comments on the Preliminary 2014 Effluent Guidelines Program Plan 

EPA Docket Number: EPA-HQ-OW-2014-0170

No.

Commenter 

Name

Commenter 

Organization

EPA 

Docket 

No. Comment Summary

1 Curt A. 

McCormick

CWA Consulting 

Services, LLC 

(CWACS)

0081 Supports EPA's evaluation of centralized waste 

treatment (CWTs) facilities to clarify whether 

facilities that accept oil and natural gas produced 

wastewaters by truck for treatment, which is 

subsequently discharged to publicly-owned 

treatment works (POTWs) meet the definition of a 

CWT (and whether they are subject to 40 CFR Part 

437 (CWTs) or 40 CFR Part 403 (General 

Pretreatment Regulations). Supports EPA's study of 

the Petroleum Refining (40 CFR Part 419) industry 

and suggests that that EPA specifically evaluate 

common problem pollutants such as benzene and 

sulfides, as well as groundwater pump-and-treat 

operations to clearly define regulated, unregulated, 

and dilute wastestreams. Opposes reopening of the 

Metal Finishing ELGs (40 CFR Part 433) because it 

could make the regulation vulnerable to weakening 

by special interest groups. Supports EPA's efforts to 

characterize nanopollutants and requests that EPA 

add biodiesel manufacturing to the list of industrial 

sectors to evaluate.
Section 4—Public Comments and Other Stakeholder Input on 

the Final 2012 and Preliminary 2014 Effluent Guidelines Program Plans

4-5

Table 4-1. Comments on the Preliminary 2014 Effluent Guidelines Program Plan 

EPA Docket Number: EPA-HQ-OW-2014-0170

No.

Commenter 

Name

Commenter 

Organization

EPA 

Docket 

No. Comment Summary

2 Roger E. 

Claff

American Petroleum 

Institute (API)

0082 Raises several issues related to the proposed 

Petroleum Refining (40 CFR Part 419) study, 

specifically the use of TRI data, EPA’s objectives 

for examining petroleum refinery feedstock metals, 

the basis for evaluating polynuclear aromatic 

hydrocarbons (PNAs), and EPA’s request for 

information on oil refining processes. Also raises 

several issues related to the proposed CWTs (40 

CFR Part 437) study including the lack of criteria 

used to define CWTs, the basis for initiating the 

study, and the need for consistency with ELGs for 

oil and gas extraction for shale gas facilities that 

direct their wastewaters to CWTs. Supports 

continued engagement and communication with 

EPA during the studies.

3 Dennis 

Lathem

Coalbed Methane 

Association of 

Alabama (CMAA)

0083 Supports EPA's decision to delist coalbed methane 

as a new subcategory under the Oil & Gas 

Extraction Category (40 CFR Part 435) because 

EPA did not identify a new wastewater treatment 

technology that would be economically achievable.

4 Jerry 

Schwartz

American Forest & 

Paper Association 

(AF&PA)

0084 Supports EPA's decisions in the Final 2012 Plan that 

no further review of the Pulp, Paper, and 

Paperboard (40 CFR Part 430) industry is necessary 

and its decision not to include the category for 

further review in the Preliminary 2014 Plan.

5 Jeffrey S. 

Hannapel

National Association 

for Surface Finishing 

(NASF)

0085, 

0093 

(duplicate 

comment)

Opposes EPA's continued preliminary review of the 

Metal Finishing Category (40 CFR Part 433) 

because EPA’s recent review of the industry under 

the Metal Products and Machinery (MP&M) 

rulemaking (40 CFR Part 438) determined further 

revisions to the guidelines are not necessary, the 

industry is not using new processes or treatment 

technologies that would suggest the need for ELG 

revisions, and POTWs may impose more stringent 

limits as necessary. 

6 Jay West American Chemistry 

Council (ACC) 

Nanotechnology 

Panel

0086 Supports EPA's review of nanomaterials; however, 

urges EPA to recognize the diversity of 

nanomaterial substances and their applications, 

work with the New Chemicals Program to 

understand nanomaterial releases in water, consider 

work on nanomaterials completed or currently 

underway, and recognize the potential for 

nanotechnology to provide new and improved tools 

for wastewater treatment.
Section 4—Public Comments and Other Stakeholder Input on 

the Final 2012 and Preliminary 2014 Effluent Guidelines Program Plans

4-6

Table 4-1. Comments on the Preliminary 2014 Effluent Guidelines Program Plan 

EPA Docket Number: EPA-HQ-OW-2014-0170

No.

Commenter 

Name

Commenter 

Organization

EPA 

Docket 

No. Comment Summary

7 Jeff 

Gunnulfsen

American Fuel & 

Petrochemical 

Manufacturers 

(AFPM)

0087 Urges EPA to demonstrate the specific concerns 

with the current Petroleum Refining ELGs (40 CFR 

Part 419). Specifically, questions the data, data 

quality, and information evaluated as part of the 

annual reviews and used to form the basis for the 

proposed study. Urges EPA to work with industry 

representatives to develop a path forward.

8 Matthew H. 

Hodges

Valero Companies 0088 Opposes further study of the Petroleum Refining (40 

CFR Part 419) industry, citing that EPA has not 

fully considered the data or data quality to support 

the decision to conduct a detailed study. Specifically 

raised issues related to the data demonstrating 

discharges of metals and dioxins, the correlation of 

crude feedstock to pollutant discharges, and EPA’s 

demonstration that the current ELGs are not 

sufficient to protect human health and the 

environment.

9 Michael 

Fulton

Association of Clean 

Water Administrators 

(ACWA)

0089 Supports further study of the Metal Finishing (40 

CFR Part 433) industry, stating that there have been 

drastic changes in the industry, including new 

chemical formulas and processes, new pollutants of 

concern, new treatment technologies, and changes 

in the scope of the metal finishing industry. 

Encourages EPA to more clearly define gray areas 

in the current regulations, such as the definition of 

etching vs. cleaning, coating vs. absorption, and 

phosphate coating vs. phosphate cleaning. 

Recommend that EPA clarify new and existing 

sources and sunset the Electroplating ELGs (40 

CFR Part 413) to require eventual compliance with 

the Metal Finishing ELGs (40 CFR Part 433). 

Recommends EPA increase the staff allocated to 

working on ELGs and pretreatment standards and 

issue future ELG Plans and Annual Review Reports 

in a timelier manner. Supports EPA’s new 

methodology used in the 2012 Annual Review 

Report. 

10 Bryan Holt Greenway Products 

Inc. 

0090 Stated that their company is currently testing a 

coagulant/flocculent/filter aid to remove 

nanoparticles, E.coli, phosphorus, and other 

particulates. 
Section 4—Public Comments and Other Stakeholder Input on 

the Final 2012 and Preliminary 2014 Effluent Guidelines Program Plans

4-7

Table 4-1. Comments on the Preliminary 2014 Effluent Guidelines Program Plan 

EPA Docket Number: EPA-HQ-OW-2014-0170

No.

Commenter 

Name

Commenter 

Organization

EPA 

Docket 

No. Comment Summary

11 Lynn Thorp

Jessica Ennis

Lauren Pagel

Scott 

Anderson

Madeleine 

Foote

Amy Mall

Deborah J. 

Nardone

Clean Water Action

Earthjustice

Earthworks

Environmental 

Defense Fund

League of 

Conservation Voters

Natural Resources 

Defense Fund

Sierra Club

0091 Oppose EPA’s decision to delist coalbed methane 

extraction and discontinue the ELG rulemaking 

because the industry produces large volumes of 

wastewater with contaminants at potentially high 

concentrations. Stated that inadequate treatment and 

discharge of these wastewaters could jeopardize the 

integrity of the surface water, that EPA’s decision to 

delist was premature, that ELGs are necessary, and 

that affordable treatments are available. Support 

EPA’s decision to undertake a detailed study of the 

CWTs (40 CFR Part 437) that accept oil and gas 

wastewaters because the ELGs are out of date, 

CWTs may be lacking treatment for pollutants in oil 

and gas wastewaters, these wastewaters could have 

impacts on drinking water sources, and pretreatment 

standards under development for discharges to 

POTWs from onshore unconventional oil and gas 

extraction could results in more discharges to 

CWTs. Additionally, commented that ongoing 

revisions to pretreatment standards for discharges to 

POTWs need to be revised to reflect changes in oil 

and gas exploration, stimulation, and extraction. 

12 Scott 

Anderson

Environmental 

Defense Fund (EDF)

0092 Supports comments from the group of 

environmental organizations. Encourages EPA to 

finalize the oil and gas ELG rulemaking as fast as 

possible due to the potential severity of the 

consequences if discharges too significantly outpace 

regulation. Supports a detailed study of the CWTs 

(40 CFR Part 437) that accept oil and gas 

wastewaters, but reminds EPA that conducting the 

CWT study is only a first steps toward materially 

improving oversight of CWTs. Provided additional 

resources and studies on oil and gas wastewaters 

and CWTs. 

13 Christopher 

Harris

NORA: Association 

of Responsible 

Recyclers, Inc. 

0094 States that revising the CWT ELG may not be 

necessary to address discharges of oil and gas 

extraction wastewater (to CWTs, POTWs, or 

surface water) and that the organization plans to be 

closely involved with any regulatory changes and/or 

guidelines for CWTs (40 CFR Part 437). Suggested 

that any new regulations and/or guidelines for CWT 

facilities could be aided by direct meetings between 

EPA, NORA’s experts in this field, and the 

operators of CWT facilities. 
Section 5—Continued Review of Select Industrial Categories

5-1 

5. CONTINUED REVIEW OF SELECT INDUSTRIAL CATEGORIES

For the 2014 Annual Review, EPA continued to evaluate several industrial categories that 

the Preliminary 2014 Plan identified as warranting further review: Metal Finishing (40 CFR Part 

433), Pesticide Chemicals (40 CFR Part 455) and brick and structural clay products 

manufacturing (not currently regulated) (U.S. EPA, 2014). 

EPA documented the usability and quality of the data supporting its continued review of 

these industrial categories, analyzed how the data could be used to improve the characterization 

of industrial wastewater discharges (universe of facilities with known or potential discharges, 

concentration and quantity of pollutants, availability and performance of advances in wastewater 

treatment), and prioritized the findings for further review. See Appendix B of this report for 

more information on data usability and quality of the data sources supporting these reviews. 

Section 5.1 through Section 5.3 of this report details EPA’s continued review of these 

three industrial categories.

5.1 Continued Review of the Metal Finishing Category (40 CFR Part 433) 

EPA reviewed the Metal Finishing Category (40 CFR Part 433) as part of the 2012 and 

2013 Annual Reviews and determined that the category warranted further review. EPA 

continued its review of this category in its 2014 Annual Review. 

During the 2012 Annual Review, EPA’s review of the Targeted National Sewage Sludge 

Survey (TNSSS), combined with available indirect discharge data from the Toxics Release 

Inventory (TRI), suggested further investigation of the Metal Finishing Category relating to the 

indirect discharge of metals, particularly chromium, nickel, and zinc, to publicly-owned 

treatment works (POTWs). These metals could transfer to sewage sludge, where their 

concentrations could diminish the sludge’s beneficial use. EPA evaluated beneficial use by 

comparing the metal concentrations against the regulatory ceiling concentrations for sewage land 

application (40 CFR 503 Subcategory B) and sewage sludge concentration limits for surface 

disposal (40 CFR 503 Subcategory C) (U.S. EPA, 2014a). EPA also received comments from the 

Association of Clean Water Administrators (ACWA) urging EPA to revise regulations or issue 

new guidance for the industry due to applicability concerns and advancements in process and 

treatment technology for metal finishing and metal finishing wastewater (ACWA, 2013). In the 

2013 Annual Review, the Metal Finishing Category also ranked high, in terms of toxic weighted 

pound equivalents (TWPE), in EPA’s toxicity ranking analysis (U.S. EPA, 2014b). 

As part of this 2014 Annual Review, EPA reviewed the scope of the existing Metal 

Finishing Effluent Limitations Guidelines and Standards (ELGs), examined the current profile of 

metal finishing operations in the U.S., and gathered data on existing and advanced metal 

finishing wastewater treatment technologies. EPA also held discussions with regional EPA 

pretreatment coordinators who are involved in the implementation of POTW pretreatment 

programs throughout the U.S. to further understand metal finishing operations and potential 

applicability issues with the Metal Finishing ELGs. The following sections present the findings 

of EPA’s continued review of the Metal Finishing Category. 
Section 5—Continued Review of Select Industrial Categories

5-2 

5.1.1 Overview of Existing ELGs Related to Metal Finishing

To provide background and context for EPA’s continued review of the Metal Finishing 

Category (40 CFR Part 433), this section provides a brief history of the development and review 

of the existing ELGs related to metal finishing operations. Metal finishing is defined as the 

process of changing the surface of an object for the purpose of improving its appearance and/or 

durability. Wastewater discharges from metal finishing operations are primarily regulated by two 

ELGs:9 pretreatment standards for existing sources (PSES) for the Electroplating Category (40 

CFR Part 413) and the effluent limitations, pretreatment standards, and new source performance 

standards (NSPS) for the Metal Finishing Category (40 CFR Part 433). 

5.1.1.1 Pretreatment Standards for Existing Sources in the Electroplating Category

EPA promulgated PSES for the Electroplating Category (40 CFR Part 413) on September 

7, 1979. The rule established pretreatment standards for facilities that indirectly discharge to 

POTWs above and below a discharge threshold of 10,000 gallons per day (gpd). Standards for 

new sources and direct dischargers were not established under this rule. The pretreatment 

standards include concentration-based limits with alternate mass-based limits for metals, 

cyanide, and total toxic organics. Facilities had the option of complying with either 

concentration- or mass-based limits. At promulgation, these standards applied to existing 

facilities that perform one or more of six electroplating operations, which are defined below and 

in the Development Document for Existing Source Pretreatment Standards for the Electroplating 

Point Source Category (U.S. EPA, 1979): 

• Electroplating: the production of a thin surface coating of one metal upon another 

by electrodeposition. This surface coating is applied to provide corrosion 

protection, wear or erosion resistance, or anti-frictional characteristics, or for 

decorative purposes. 

• Electroless plating: a chemical reduction process that depends on the catalytic 

reduction of a metallic ion in an aqueous solution containing a reducing agent and 

the subsequent deposition of metal without the use of external electrical energy. 

• Anodizing: an electrolytic oxidation process that converts the surface of the metal 

to an insoluble oxide. 

• Coating: the process of chromating, phosphating, metal coloring, and immersion 

plating.10 In chromating, a portion of the base metal is converted to a component 

of the film by reaction with aqueous solutions containing hexavalent chromium 

and active organic or inorganic compounds. Phosphate coatings are used to 

provide a good base for paints and other organic coatings, to condition the 

surfaces for cold forming operations by providing a base for drawing compounds 

and lubricants, and to impart corrosion resistance to the metal surface by the 

 

9 Discharges from facilities performing metal finishing operations may also be regulated under other ELGs (e.g., 

aluminum forming, iron and steel) that take precedence over the Metal Finishing ELGs, as discussed in Section 

5.1.1.2. 

10 The Metal Finishing ELGs refer to immersion plating as passivation.
Section 5—Continued Review of Select Industrial Categories

5-3 

coating itself or by providing a suitable base for rust-preventative oils or waxes.

Metal coloring by chemical conversion methods produces a large group of 

decorative finishes. Immersion plating is a chemical plating process in which a 

thin metal deposit is obtained by chemical displacement of the basis metal. A 

common example of immersion plating is the deposition of copper on steel from 

an acid copper solution. 

• Etching and chemical milling: producing specific design configurations and 

tolerances on metal parts by controlled dissolution with chemical reagents or 

etchants. Included in this classification are the processes of chemical milling, 

chemical etching, bright dipping, electropolishing, and electrochemical 

machining.11 Chemical etching is the same process as chemical milling, but with 

much lower rates and depths of metal removal. Bright dipping is a specialized 

form of etching, used to remove oxide and tarnish from ferrous and nonferrous 

materials. This unit operation also includes the stripping of metallic coatings.

• Printed circuit board manufacturing: the formation of a circuit pattern of 

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

plastic or glass. It usually involves cleaning and surface preparation, catalyst and 

electroless plating, pattern printing and masking, electroplating, and etching. 

The National Association of Metal Finishers and the Institute of Interconnecting and 

Packaging Electronic Circuits challenged the PSES for the Electroplating Category. On March 7, 

1980, EPA entered into a settlement agreement with these two organizations, agreeing to publish 

amendments to the final electroplating pretreatment standards if the petitioners dismissed their 

petition for review of the standards. These amendments were implemented on January 28, 1981 

(U.S. EPA, 1981). As a result, EPA agreed to develop best available technology economically 

achievable (BAT) effluent limits, NSPS, and pretreatment standards for new and existing sources 

(PSNS and PSES) under a new regulation for the Metal Finishing Category. 

Metal finishing facilities are categorized as either captive facilities or job shops, which 

EPA defined as follows (U.S. EPA, 1984): 

• Captive facility: a facility that in a calendar year owns more than 50 percent (on 

an area basis) of the materials undergoing metal finishing. Captive facilities were 

further categorized as integrated or non-integrated to characterize the wastewater 

discharges generated. Integrated facilities combine electroplating waste streams 

with significant process waste streams not covered by the Electroplating 

Category, whereas non-integrated facilities have significant wastewater 

discharges only from electroplating operations covered under the Electroplating 

Category.

• Job shop: a facility that in a calendar year owns less than 50 percent (on an area 

basis) of the materials undergoing metal finishing. Although job shops can be also 

 

11 The Metal Finishing ELGs do not include electropolishing or electrochemical machining in the classification of 

etching and chemical milling. 
Section 5—Continued Review of Select Industrial Categories

5-4 

categorized as integrated and non-integrated, approximately 97 percent were 

found to be non-integrated during the development of the new regulation. 

By February 15, 1986, all existing captive facilities under the Electroplating Category 

shifted to the Metal Finishing Category and were required to comply with the Metal Finishing 

ELGs. Any new sources of wastewater discharges (both direct and indirect) as well as existing, 

direct discharging sources from metal finishing facilities that were not regulated under the 

Electroplating Category would also fall under the Metal Finishing Category. Only existing 

indirect discharging job shops, including independent printed circuit board (IPCB) 

manufacturers, remained in the existing Electroplating Category after the final compliance date 

for the Metal Finishing ELGs.

5.1.1.2 Effluent Guidelines for the Metal Finishing Category 

The Metal Finishing ELGs were promulgated on July 15, 1983. They establish one set of 

concentration-based limitations, summarized in Table 5-1, that apply across a single subpart 

(subpart A: Metal Finishing). Direct dischargers comply with BAT and NSPS limits, whereas 

indirect dischargers comply with PSES and PSNS limits for existing and new sources, 

respectively. As the table shows, the limits are the same between new sources and existing 

sources of industry wastewater, except for cadmium, which has a lower limit for direct or 

indirect new sources of metal finishing wastewater. The Metal Finishing ELGs regulate 

wastewater discharges from the same six core operations addressed in the PSES for the 

Electroplating Category. If any of these six operations is present, the Metal Finishing ELGs 

apply to an additional 40 unit operations (summarized in Table 5-2) (U.S. EPA, 1983). 
Section 5—Continued Review of Select Industrial Categories

5-5 

Table 5-1. Regulated Pollutants and ELG Limits for the Metal Finishing Category, 

Subpart A

Process Operations Covered Pollutant

BAT/PSES

Daily Max 

(Monthly Average) 

(mg/L)

NSPS/PSNS 

Daily Max 

(Monthly Average) 

(mg/L)

See Table 5-2 for the list of 46 unit operationsa Silver 0.43 (0.24) 0.43 (0.24)

Copper 3.38 (2.07) 3.38 (2.07)

Lead 0.69 (0.43) 0.69 (0.43)

Cyanideb 1.20 (0.65) 1.20 (0.65)

Cadmium 0.69 (0.26) 0.11 (0.07)

Chromium 2.77 (1.71) 2.77 (1.71)

Nickel 3.98 (2.38) 3.98 (2.38)

Zinc 2.61 (1.48) 2.61 (1.48)

For industrial facilities with cyanide treatment, and 

upon agreement between a source subject to those 

limits and the pollution control authority, the 

following amenable cyanide limit may apply in 

place of the total cyanide limit.

Cyanide 

amenable to 

alkaline 

chlorination 

0.86 (0.32) 0.86 (0.32)

Source: 40 CFR Part 433. a The provisions of this subpart apply to discharges from six electroplating operations on any basis material: 

electroplating, electroless plating, anodizing, coating (chromating, phosphating, and coloring), chemical etching 

and milling, and printed circuit board manufacturing. If any of these six operations are present, the provisions of 

this subpart also apply to discharges from 40 additional metal finishing operations, listed in Table 5-2. These 

limits do not apply to (1) metallic platemaking and gravure cylinder preparation conducted within or for printing 

and publishing facilities or (2) existing indirect discharging job shops and independent printed circuit board 

manufacturers, which are covered by 40 CFR part 413.

b Anti-dilution provisions are stipulated in 40 CFR Part 433, which require self-monitoring for cyanide after 

cyanide treatment and before dilution with other waste streams. 
Section 5—Continued Review of Select Industrial Categories

5-6 

Table 5-2. Unit Operations Regulated by ELGs for the Metal Finishing Category

Six Electroplating Operations 

(Introduced in 40 CFR Part 413)

40 Additional Metal Processing Unit Operations

(Introduced in 40 CFR Part 433)

• Electroplating

• Electroless plating 

• Anodizing 

• Coating 

• Etching and chemical milling 

• Printed circuit board manufacturing 

• Cleaning

• Machining

• Grinding

• Polishing

• Barrel finishing

• Burnishing

• Impact deformation

• Pressure deformation

• Shearing

• Heat treating

• Thermal cutting

• Welding 

• Brazing

• Soldering

• Flame spraying

• Sand blasting

• Abrasive jet machining

• Electrical discharge machining

• Electrochemical machining

• Electron beam machining

• Laser beam machining

• Plasma arch machining

• Ultrasonic machining

• Sintering

• Laminating

• Hot dip coating

• Sputtering

• Vapor plating

• Thermal infusion

• Salt bath descaling 

• Solvent degreasing

• Paint stripping

• Painting

• Electrostatic painting

• Electropainting 

• Vacuum metalizing

• Assembly

• Calibration

• Testing

• Mechanical plating

Source: 40 CFR Part 433. 

In some cases, ELGs for other industrial categories may be effective and applicable to 

wastewater discharges from metal finishing operations. The rule specified the following 

regulations that take precedence over 40 CFR Parts 413 and 433 when such an overlap occurs: 

• 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);4 and

• Nonferrous Forming (40 CFR Part 471).12

During the development of the Metal Products and Machinery (MP&M) rule (40 CFR 

Part 438, promulgated in 2003), EPA evaluated all industries involved in the “manufacture, 

rebuild or maintenance of metal parts, products, or machines,” including facilities in the 

 

12 40 CFR Parts 469 and 471 were added in the corrections to the final rule dated September 26, 1983.
Section 5—Continued Review of Select Industrial Categories

5-7 

Electroplating and Metal Finishing Categories. EPA proposed limits for these facilities under 

four MP&M subcategories: general metals, metal finishing job shops, non-chromium anodizing, 

and printed wiring board (U.S. EPA, 2000). However, following consideration of comments 

submitted on the proposed MP&M regulation, EPA decided not to promulgate limits for these 

subcategories (68 FR 25690). Table 5-3 summarizes and compares these limits from the 

proposed MP&M regulation to the existing limits from the Metal Finishing and Electroplating 

ELGs. 
Section 5—Continued Review of Select Industrial Categories

5-8 

Table 5-3. Comparison of Maximum Monthly Average Effluent Limits Between Parts 413 and 433 and the Proposed Limits 

for Part 438 

Regulation

Electroplating

40 CFR Part 413a 

Metal Finishing

40 CFR Part 433

Metal Products and Machinery

40 CFR Part 438 Proposed Limits

Subcategories

>10,000 

gpdb

<10,000 

gpdb Metal Finishing General Metals

Metal Finishing 

Job Shops

Non-Cr

Anodizing

Printed Wiring 

Board

Standards

PSES Only

NSPS/

PSNS

BAT/ 

PSES

NSPS/

PSNS

BAT/

PSESc

NSPS/

PSNS

BAT/

PSES

NSPS 

Only

BAT 

Only

NSPS/

PSNS

BAT/ 

Pollutant Unit PSES

TSSd mg/L 18 18 18 31 22 31 18 31

Oil and greased mg/L 12 12 12 26 12 26 12 26

TOC mg/L 50 50 59 59 67 67

Total organics 

parameter

mg/L 4.3 4.3 4.3 4.3 4.3 4.3

Total metals mg/L 5.0

Aluminum mg/L 4.0 4.0

Cadmium mg/L 0.5 0.5 0.07 0.26 0.01 0.09 0.01 0.09

Chromium mg/L 2.5 1.71 1.71 0.07 0.14 0.07 0.55 0.07 0.14

Copper mg/L 1.8 2.07 2.07 0.16 0.28 0.16 0.57 0.01 0.28

Total cyanide mg/L 0.23 0.65 0.65 0.13 0.13 0.13 0.13 0.13 0.13

Amenable cyanide mg/L 1.5 0.32 0.32 0.07 0.07 0.07 0.07 0.07 0.07

Lead mg/L 0.3 0.3 0.43 0.43 0.03 0.03 0.03 0.09 0.03 0.03

Manganese mg/L 0.18 0.09 0.18 0.10 0.09 0.09 0.18 0.64

Molybdenum mg/L 0.49 0.49 0.49 0.49

Nickel mg/L 1.8 2.38 2.38 0.75 0.31 0.75 0.64 0.31 0.31 0.75 0.14

Silver mg/L 0.5e 0.24 0.24 0.03 0.09 0.03 0.06

Sulfide, total mg/L 13 13 13 13 13 13

Tin mg/L 0.03 0.67 0.03 1.4 0.07 0.14

Zinc mg/L 1.8 1.48 1.48 0.06 0.22 0.06 0.17 0.22 0.22 0.06 0.22

Sources: (U.S. EPA, 1979; U.S. EPA, 1983; U.S. EPA, 2000). 

Gray highlighting indicates that no limits were set for the pollutant. a See 40 CFR Part 413 for alternative mass-based limits. Facilities could comply with either concentration-based or mass-based limits. 

b

 EPA established discharge limits based on a wastewater production threshold of 10,000 gallons per day. Similar limits were set for all six subparts of Part 

413, except where noted in footnote e. c Part 438 proposed a minimal flow rate of 1 million gallons per year to trigger compliance with PSES.

d Part 438 did not propose TSS and oil and grease limits for PSES or PSNS. e The silver pretreatment standard applies only to Subpart B, precious metals plating.
Section 5—Continued Review of Select Industrial Categories

5-9 

5.1.2 Profile of Metal Finishing Operations in the U.S.

As part of the 2014 Annual Review, EPA updated and evaluated the current industry 

profile for the Metal Finishing Category. This section identifies the number of facilities currently 

regulated under the category (40 CFR Part 433), the types of metal finishing operations and 

discharge practices that are in use, and the types of wastewater treatment technologies that are 

available or are being evaluated for treating metal finishing wastewater. 

5.1.2.1 Number of Facilities 

At promulgation of the 1983 Metal Finishing ELGs, the Metal Finishing and 

Electroplating Categories included a total of 13,470 facilities, consisting of 10,000 captive 

facilities and 3,470 job shops and IPCB manufacturers (U.S. EPA, 1984). The existing captive 

facilities ultimately fell into the Metal Finishing Category (after the final compliance date) and 

the 3,470 job shops and IPCB manufacturers remained in the Electroplating Category. 

EPA evaluated the metal finishing industry, as part of the MP&M Rulemaking efforts. 

EPA estimated that about 12,700 facilities were performing metal finishing operations, classified 

into four general subcategories (U.S. EPA, 2000): general metals, metal finishing job shops, nonchromium anodizing, and printed wiring boards (see Table 5-4). These estimates were primarily 

based on responses to industry surveys sent to facilities in 1989 and 1996. 

Source: (U.S. EPA, 2000) a Also known as IPCB manufacturers in Parts 413 and 433. 

The scope of facilities included in the Metal Finishing Category is based on process 

operations rather than industry sectors; therefore, facilities to which the Metal Finishing ELGs 

may apply can be classified under various metal processing and metal forming industry 

classifications. The Guidance Manual for Electroplating and Metal Finishing Pretreatment 

Table 5-4. Estimated Number of Metal Finishing Facilities Identified During the MP&M 

Rulemaking Efforts 

Applicable Subpart in 

Proposed Part 438 Subpart Description

Number of 

Facilities

General Metals This subcategory was created as a catch-all for facilities that 

discharge metal-bearing wastewater (with or without oil-bearing 

wastewater) but do not fall under the other MP&M subcategories. It 

may cover more than just facilities in the Metal Finishing Category. 

10,484

Metal Finishing Job Shops This subcategory included facilities covered under 40 CFR Part 413. 1,491

Non-Chromium Anodizing This subcategory includes facilities that perform aluminum 

anodizing without using chromic acid or dichromate sealants.

93

Printed Wiring Boardsa This subcategory covers wastewater discharges from the 

manufacture, maintenance, and repair of printed wiring boards (i.e., 

circuit boards), excluding IPCB manufacturers that are job shops. 

609

Total Number of Facilities 12,677
Section 5—Continued Review of Select Industrial Categories

5-10 

Standards identified the following two-digit Standard Industrial Classification (SIC) codes under 

which regulated facilities generally fall (U.S. EPA, 1984):13 

• 34: Fabricated Metal Products, Except Machinery and Transportation; 

• 35: Machinery, Except Electrical; 

• 36: Electrical and Electronic Machinery, Equipment and Supplies; 

• 37: Transportation Equipment; 

• 38: Measuring, Analyzing and Controlling Instruments: Photograph; Optical 

Goods; Watches and Clocks; and

• 39: Miscellaneous Manufacturing Industries. 

In the conversion of the SIC system to the North American Industry Classification 

System (NAICS) in the late 1990s, EPA reviewed these SIC codes and determined that they 

corresponded to 200 NAICS codes under which facilities for the Metal Finishing Category could 

be identified. See EPA’s Technical Support Document for the Annual Review of Existing Effluent 

Guidelines and Identification of Potential New Point Source Categories, known as the 2009 

Screening-Level Analysis or SLA Report, for additional details (U.S. EPA, 2009). 

As part of the 2014 Annual Review, EPA searched for more recent data to determine the 

number of facilities that fall into the Metal Finishing Category. The 2007 Economic Census 

provides a general industry description for each NAICS code under which these facilities may 

fall; however, it does not detail facility-specific process operations or wastewater discharge 

practices, which is the basis for determining whether the Metal Finishing ELGs would apply to 

specific facilities. In the 2011 Annual Review, EPA identified 166,356 facilities included in the 

2007 Economic Census for the 200 NAICS codes. However, this number includes establishments 

that are distributors or sales facilities, not just manufacturers (U.S. EPA, 2012). It may also 

include facilities that do not conduct the six core operations and would not be regulated under the 

Metal Finishing ELGs. In previous annual reviews, EPA has identified the number of facilities 

submitting discharge monitoring reports (DMRs) and reporting to EPA’s TRI. However, EPA 

determined that these data sources include only a fraction of the facilities that would fall under 

the applicability of the Metal Finishing Category due to the limitations of the data sets. For 

example, small establishments (less than 10 employees) are not required to report to TRI, and 

DMR data are limited concerning indirect discharges from industrial facilities to POTWs. See 

the 2009 SLA Report (U.S. EPA, 2009) for more details on the limitations of these data sets. 

Therefore, these data sources do not provide a complete picture of the metal finishing industry. 

The scope of facilities reporting to DMR and TRI is further discussed in Section 5.1.2.3. 

Some EPA regions have maintained lists of industrial users subject to 40 CFR Part 433 

that discharge metal finishing wastewater to POTWs; however, a national inventory of metal 

finishing facilities does not exist. For the 2014 Annual Review, EPA was not able to determine 

how the industry is currently distributed between job shops, IPCB manufacturers, and captive 

 

13 Although facilities performing metal finishing operations generally fall under these SIC codes, not all facilities 

under the codes may be subject to the Metal Finishing ELGs. These facilities may not perform the six electroplating 

operations that would require them to comply with the Metal Finishing ELGs. Additionally, these facilities may be 

subject to other metal ELGs that take precedence over the Metal Finishing ELGs. 
Section 5—Continued Review of Select Industrial Categories

5-11 

integrated and non-integrated facilities based on available information. This is primarily because 

the applicability of the ELGs are based on operations not industry sectors; therefore, it is difficult 

to identify how many of the estimated facilities would be covered by the rule and how the 

distribution of facilities may have changed over time. EPA did not conduct a survey as part of 

the 2014 Annual Review to obtain updated industry profile information. 

Based on a recent 2008 National Center for Manufacturing Sciences review of the surface 

finishing industry (including metal finishing), the industry has trended toward an extremely 

fragmented market since 1983, with market competition dispersed among many companies. With 

expanding global markets, U.S. firms have more recently attempted to concentrate the industry 

(i.e., incorporate the smaller job shops into larger companies) to achieve economies of scale, 

expand niche markets, and provide a larger range of finishing services in a global market. Many 

firms have also shifted surfacing operations to non-U.S. locations such as Asia, India, Mexico, 

Canada, and Europe to further reduce costs (Chalmer, 2008). 

5.1.2.2 Metal Finishing Operations

Metal finishing is the process of changing the surface of an object by creating a thin layer 

of metal or metal precipitate on the surface to impart the desired surface characteristics to the 

final product, such as corrosion resistance, wear resistance, and hardness. The operations 

performed and the sequence of operations at a metal finishing facility can vary and depend on a 

number of factors (e.g., raw materials used, industry sector, product specifications) and may 

result in significant wastewater generation (U.S. EPA, 2000). 

The Metal Finishing ELGs cover wastewater discharges from six primary metal finishing 

operations and where these operations apply; the ELGs also cover wastewater discharges from 

40 supplemental metal finishing operations (as listed in Table 5-2, and further described in 

Appendix C). Metal finishing operations usually begin with materials in the form of raw stock 

(rods, bars, sheets, castings, forgings, etc.) and can progress to the most sophisticated surface 

finishing operations. Because of the differences in facility size and processes, production 

facilities are custom-tailored to the specific needs of each individual plant. Figure 5-1 illustrates 

the variation in the number of unit operations that can be performed in facilities within the metal 

finishing industry, depending upon the complexity of the product. The possible variations of unit 

operations within the metal finishing industry are extensive and could require the use of nearly 

all unit operations, while a simple product might require only a single operation (U.S. EPA, 

1983). 

Many different raw materials are used by facilities in the Metal Finishing Category. 

During the development of the 1983 Metal Finishing ELGs, the basis materials were almost 

exclusively metals which range from common copper and steel to extremely expensive high 

grade alloys and precious metals, but may also include glass, plastic, and other non-conductive 

materials. The materials used in metal finishing unit operations can contain acids, bases, cyanide, 

metals, complexing agents, organic additives, oils and detergents. All of the basis materials and 

finishing raw materials can potentially enter wastewater streams during the production sequence. 
Section 5—Continued Review of Select Industrial Categories

5-12 

Adapted from (U.S. EPA, 1983) 

Figure 5-1. Metal Finishing Process Application 

Since the promulgation of the Metal Finishing ELGs, process technologies and 

chemistries have evolved. Materials currently used in industry include the following: 

• Transition metal coatings (TMCs) with oxides of zirconium, vanadium, and 

titanium (Dunham, 2013; Hopwood, 2012). Environmental regulations restricting 

phosphate and chromium discharges make traditional metal coatings, which 

include iron and zinc phosphate and chromium conversion coatings, less 

desirable. The application of TMCs uses a fluorozirconic or fluorotitanic acid or 

the more commonly used nitric acid (in place of phosphoric acid solvent) 

(Hopwood, 2012; LaFlamme, 2009). Application of TMCs generates less volume 

of sludge and less toxic sludge that is not subject to hazardous waste disposal 

regulations (Dunham, 2013). Application of TMCs also generates wastewater that 

is phosphate-free; however, the wastewater may contain metals that do not have 

specific discharge effluent limits in the Metal Finishing ELGs (e.g., zirconium, 

vanadium, and titanium). 

• Trivalent chromium coatings, to replace hexavalent chromium coatings for 

conventional chromium plating on aluminum, stainless steel, nickel, zinc-nickel 

alloys, and magnesium alloys (Manavbasi, 2012; U.S. EPA, 2013). Trivalent 

chromium is a less toxic oxidation state of chromium. Use of trivalent coatings 

also provides operational cost savings because it eliminates the need for 

wastewater pretreatment to reduce hexavalent chromium to its more treatable 

trivalent form (Weber, 2013). 

• Electrodeposited aluminum, zinc-nickel finish, and nickel fluorocarbon polymer

as alternate finishes to cadmium plating for aerospace applications. These 

alternative finishes are applied to aluminum objects using electrodeposition and 
Section 5—Continued Review of Select Industrial Categories

5-13 

eliminate cadmium in wastewater generated during this process (Ogundiran, 

2011). Metal Finishing ELGs contain limitations for cadmium, zinc, and nickel, 

but do not contain limitations for aluminum. 

• Molybdate-based self-healing coatings, to replace self-healing hexavalent 

chromium coatings on aluminum in the defense and aerospace industry. The 

coating formulation performs comparably to hexavalent chromium coatings and 

can be applied to all aluminum products to provide a corrosion protective surface 

that will heal itself when damaged (Wolterbeek, 2012). Use of this alternative 

coating eliminates hexavalent chromium in wastewater generated during this 

process. 

• Graphene nanocomposite coatings, to replace hexavalent chromium for hard 

chromium plating applications. Use of this process technology eliminates the use 

and subsequent handling of hexavalent chromium in spent plating baths and 

rinsewater (Dennis, 2014). 

• High-velocity oxygen-fueled thermal spray application, to replace hard chromium 

electroplating. This process technology provides a dry coating application 

process, which eliminates the need for spent chromium plating baths and reduces 

the amount of wastewater generated. Use of this process may generate additional 

waste streams, including overspray powder and post-treatment grinding coolant 

wastes (Legg, n.d.). 

These emerging processes have not yet been widely applied for many metal finishing 

operations, and Chalmer anticipates that many operations will continue to use traditional inputs 

through 2020 (Chalmer, 2008). 

5.1.2.3 Discharge Practices

Metal finishing wastewater comprises primarily rinsewater from rinsing and drying steps 

during the metal finishing process. In the Metal Finishing Rulemaking development, EPA 

identified 10,561 out of 13,470 facilities (or 78 percent) that indirectly discharge to surface water 

via POTWs. These facilities were evenly distributed between job shops, non-integrated captive 

facilities, and integrated captive facilities. The remaining 2,909 facilities (or 22 percent) directly 

discharged to surface water, with captive facilities (both integrated and non-integrated) 

predominantly performing this practice (U.S. EPA, 1983). The 1983 rule did not capture the 

number of facilities in the industry that reused wastewater.

During the MP&M Rulemaking development, EPA looked at a broad range of industries, 

including the metal finishing industry, and estimated that 92 percent of the facilities to which the 

rule would apply were indirect dischargers and 7 percent were direct dischargers. A small 

percentage of facilities performed both direct and indirect discharge practices (U.S. EPA, 2000). 

As with the Metal Finishing ELGs, EPA did not evaluate the number of facilities reusing 

wastewater. 

Using the DMR Pollutant Loading Tool, EPA reviewed the number of facilities with 

NPDES permits that allow them to directly discharge to surface waters as well as the number of 
Section 5—Continued Review of Select Industrial Categories

5-14 

facilities reporting direct and indirect discharges to EPA’s TRI program, which may provide a 

relative indication of current discharge practices. Table 5-5 provides a summary of the facilities 

reporting to DMR and TRI from 2010 to 2012. The DMR data represent the universe of direct 

dischargers reporting under the 200 NAICS codes that generally cover facilities in the Metal 

Finishing Category. Compared to the approximate 12,700 facilities in the Metal Finishing 

Category (see Section 5.1.2.1), fewer than 6 percent of the facilities had permits to directly 

discharge in 2012. Additionally, nearly 90 percent of the direct dischargers are classified as 

minor dischargers.14 The majority of facilities reporting to TRI are indirect dischargers, which is 

consistent with the historic profiles of the Metal Finishing industry. However, the number of 

facilities and estimated discharges associated with both indirect and direct discharging facilities 

reporting to TRI provide an incomplete representation of the industry. TRI data are limited 

because reporting is required for a select number of facilities depending on the industry sector, 

number of employees, and activity thresholds (see the 2009 SLA Report (U.S. EPA, 2009) for 

additional details on limitations of the data sets). 

Table 5-5. Number of Metal Finishing Facilities by Discharge Practice

Year

DMRa TRI

Minor

Dischargers

Major

Dischargers Total

Indirect 

Discharge

Only

Direct 

Discharge

Only

Both Indirect and 

Direct Discharge Total

2010 807 79 886 1,290 276 268 1,834

2011 714 76 790 1,241 279 270 1,790

2012 639 72 711 1,218 267 247 1,732

Source: DMR Pollutant Loading Tool. a Facilities reporting to DMR are direct dischargers only. 

Because facilities reusing wastewater are not required to report metal finishing operations 

and wastewater handling practices under DMR or TRI, EPA could not determine the number of 

facilities engaged in and the currently employed practices for wastewater recovery and reuse. 

However, according to regional EPA pretreatment coordinators, efforts to minimize and 

eliminate wastewater discharges are becoming more common for the industry. 

5.1.2.4 Metal Finishing Wastewater Characteristics 

Water is used for rinsing workpieces, washing away spills, air scrubbing, process fluid 

replenishment, cooling and lubrication, washing of equipment and workpieces, quenching, spray 

booths and assembly and testing during the metal finishing process. Plating and cleaning 

operations are typically the biggest water users. While the majority of metal finishing operations 

use water, some of them are completely dry. Table 5-6 provides a summary of the anticipated 

water usage by unit operation, as evaluated during the development of the 1983 Metal Finishing 

 

14 To provide an initial framework for permitting priorities, EPA developed a major/minor classification system for 

industrial and municipal wastewater discharges. Major discharges usually have the capability to impact receiving 

waters if not controlled and, therefore, have received more regulatory attention than minor discharges. Major/minor 

classifications are determined by permitting authorities and vary state to state. See Section 3.2.4 from EPA’s 2013 

Annual Review Report for more information (U.S. EPA, 2014b). 
Section 5—Continued Review of Select Industrial Categories

5-15 

ELGs. The type of rinsing can have a marked effect on water use as can the flow rates within the 

particular rinse types. Product quality requirements often dictate the amount of rinsing needed 

for specific parts. Parts requiring extensive surface preparation will generally necessitate the use 

of larger amounts of water (U.S. EPA, 1983). This wastewater may require further treatment 

before discharge and can be directly discharged to surface water, indirectly discharged through 

POTWs, or recycled/reused.

Table 5-6. Water Use by Unit Operation 

Unit Operation Major Water 

Use

Minimal Water 

Use Zero Discharge

1 Electroplating x

2 Electroless Plating x

3 Anodizing x

4 Conversion Coating x

5 Etching (Chemical Milling) x

6 Cleaning x

7 Machining x

8 Grinding x

9 Polishing x

10 Tumbling (Barrel Finishing) x

11 Burnishing x

12 Impact Deformation x

13 Pressure Deformation x

14 Shearing x

15 Heat Treating x

16 Thermal Cutting x

17 Welding x

18 Brazing x

19 Soldering x

20 Flame Spraying x

21 Sand Blasting x

22 Other Abrasive Jet Machining x

23 Electric Discharge Machining x

24 Electrochemical Machining x

25 Electron Beam Machining x

26 Laser Beam Machining x

27 Plasma Arc Machining x

28 Ultrasonic Machining x

29 Sintering x

30 Laminating x

31 Hot Dip Coating x

32 Sputtering x

33 Vapor Plating x

34 Thermal Infusion x

35 Salt Bath Descaling x

36 Solvent Degreasing x

37 Paint Stripping x

38 Painting x

39 Electrostatic Painting x

40 Electropainting x
Section 5—Continued Review of Select Industrial Categories

5-16 

Table 5-6. Water Use by Unit Operation

Unit Operation

Major Water 

Use

Minimal Water

Use

Zero Discharge

41 Vacuum Metalizing x

42 Assembly x

43 Calibration x

44 Testing x

45 Mechanical Plating x

46 Printed Circuit Board Manufacturing x

Source: (U.S. EPA, 1983)

Although wastestream characteristics may vary depending on the unit operations used in 

the metal finishing process, according to the 1983 Metal Finishing ELGs, wastestreams were 

generally characterized by the types of inorganic and organic constituents, as listed in Table 5-7

(U.S. EPA, 1983). 

Table 5-7. Waste Characteristics by Unit Operation

Waste Characteristics

Inorganics Organics

Common 

Metals

Precious

Metals

Complexed 

Metals

Chromium 

(Hexavalent) Cyanide Oils ToxicOrganics

Unit Operation

1 Electroplating x x x x

2 Electroless Plating x x x x

3 Andodizing x x

4 Conversion Coating x x x x

5 Etching (Chemical

Milling) x x x x

6 Cleaning x x x x x x x

7 Machining x x

8 Grinding x x

9 Polishing x x x

10 Tumbling x x x x

11 Burnishing x x x x

12 Impact Deformation x x

13 Pressure

Deformation x x

14 Shearing x x

15 Heat Treating x x x x

16 Thermal Cutting x

17 Welding x

18 Brazing x

19 Soldering x x

20 Flame Spraying x

21 Sand Blasting x

22 Other Abrasive Jet

Machining x x

23 Electric Discharge 

Machining x x

24 Electrochemical

Machining x x x x
Section 5—Continued Review of Select Industrial Categories

5-17 

Table 5-7. Waste Characteristics by Unit Operation

Waste Characteristics

Inorganics Organics

Common 

Metals

Precious 

Metals

Complexed 

Metals

Chromium 

(Hexavalent) Cyanide Oils Toxic Organics

Unit Operation

25 Electron Beam 

Machining x 

26 Laser Beam 

Machining x 

27 Plasma Arc 

Machining x 

28 Ultrasonic 

Machining x 

29 Sintering x

30 Laminating x

31 Hot Dip Coating x

32 Sputtering x

33 Vapor Plating x

34 Thermal Infusion x

35 Salt Bath Descaling x x

36 Solvent Degreasing x x x

37 Paint Stripping x x x

38 Painting x x x

39 Electrostatic Painting x x x x

40 Electropainting x x

41 Vacuum Metalizing x

42 Assembly x x x

43 Calibration x x

44 Testing x x

45 Mechanical Plating x x

46

Printed Circuit 

Board 

Manufacturing

x x x x x x 

Source: (U.S. EPA, 1983) 

During the 2012 Annual Review, EPA’s review of the TNSSS, combined with available 

TRI indirect discharge data, identified the Metal Finishing Category (40 CFR Part 433) as 

potentially discharging high concentrations of metals, particularly chromium, nickel, and zinc, to 

POTWs. These metals could transfer to sewage sludge and diminish its beneficial use (U.S. EPA, 

2014a). For the 2014 Annual Review, EPA reviewed 2011 DMR and TRI facility pollutant 

discharge data for the Metal Finishing Category and identified the top pollutants discharged by 

the industry in terms of TWPE, as listed in Table 5-8 and Table 5-9, respectively. Table 5-8 and 

Table 5-9 also identify whether the pollutants are currently regulated under 40 CFR Part 433. 

This analysis confirms discharges of nickel and zinc, which are currently regulated by the Metal 

Finishing ELGs. As stated above, however, TRI reporting is only required for select facilities. In 

addition, TRI discharges may be estimated, not actually measured. Therefore, the number of 

facilities and estimated discharges associated with both indirect- and direct-discharging facilities 

reporting to TRI is an incomplete representation of the industry; see the 2009 SLA Report (U.S. 

EPA, 2009) for additional details on limitations of TRI. 
Section 5—Continued Review of Select Industrial Categories

5-18 

Table 5-8. Metal Finishing Category Top 2011 DMR Pollutants

Reported Pollutant

Number of Facilities 

Reporting Pollutant 

Discharges TWPE

% of 

TWPE

Regulated Pollutant

Under 40 CFR Part 

433

PCB-1248a 2 44,200 29.1 No

Polychlorinated biphenyls (PCBs)a 3 28,200 18.5 No

Chrysene 8 24,400 16.0 No

Silver, total (as Ag) 13 10,700 7.0 Yes

PCB-1268a 1 9,310 6.1 No

Zinc, total (as Zn) 113 5,560 3.7 Yes

Chlorine, total residual 83 3,570 2.3 No

PCB-1260a 1 3,220 2.1 No

Lead, total (as Pb) 41 3,040 2.0 Yes

Copper, total (as Cu) 111 2,950 1.9 No

Copper, total recoverable 28 2,870 1.9 Yes

Top Pollutant Total 138,000 90.7 NA

Metal Finishing Category Total 152,000 100.0 NA

Source: DMR Pollutant Loading Tool. 

NA: Not applicable. a “Polychlorinated biphenyls (PCBs)” refers to the grouping of PCB compounds; PCB-1248, PCB-1268, and 

PCB-1260 are individual PCB compounds. Facilities may report PCBs as a grouping or as individual 

compounds, depending on what is specified in their permits.

Table 5-9. Metal Finishing Category Top 2011 TRI Pollutants

Reported Pollutant

Number of Facilities 

Reporting Pollutant 

Discharges TWPE

% of 

TWPE

Regulated Pollutant

Under 40 CFR Part 

433

Copper and copper compounds 692 13,600 18.7 Yes (as total copper)

Lead and lead compounds 734 11,100 15.1 Yes (as total lead)

Silver and silver compounds 15 10,800 14.9 Yes (as total silver)

Mercury and mercury compounds 13 5,160 7.1 No

Nitrate compounds 208 2,710 3.7 No

Manganese and manganese 

compounds

357 2,070 2.8 No

Zinc and zinc compounds 268 1,640 2.2 Yes (as total zinc)

Nickel and nickel compounds 599 1,400 1.9 Yes (as total nickel)

Top Pollutant Total 48,500 94.3 NA

Metal Finishing Category Total 51,700 100 NA

Source: TRILTOutput2011_v1.

NA: Not applicable. 

As discussed in Section 5.1.2.2, EPA determined that new chemical alternatives in the 

industry could generate wastewater containing pollutants that are not currently regulated under 

the Metal Finishing ELGs (40 CFR Part 433). Existing processes have used base metals such as 

aluminum, calcium, magnesium, manganese, iron, and tin. Some emerging processes use 

titanium, zirconium, vanadium, and nanocomposites that were not considered in the Metal 

Finishing ELGs (Dennis, 2014; Dunham, 2013). Additionally, there are new chemical 

formulations used in cleaning, surface treatment, and post-treatment operations, including 

fluorides, sulfides, borates, phosphates, nitrates, and sulfates. These potential new pollutants of 

concern are not currently regulated by the Metal Finishing ELGs and are not currently reported 
Section 5—Continued Review of Select Industrial Categories

5-19 

to DMR or TRI; therefore, EPA is uncertain at this point about the extent of their presence in 

metal finishing wastewater.

In EPA’s discussions with regional EPA pretreatment coordinators, the coordinators did 

not identify any issues related to the treatability of metal finishing wastewater at POTWs, 

particularly related to chromium, nickel, and zinc. However, the pretreatment coordinators did 

note concern about potential new pollutants introduced by more recent chemical alternatives 

used in metal finishing. For example, coordinators were concerned about the increasing use of 

nanotechnologies in metal finishing processes, which involve nanoscale metal particles that may 

not have existing methods of detection, regulation, and treatment. (EPA’s review of engineered 

nanomaterials in industrial wastewater is discussed in Section 6.1 of this report). In addition, 

pretreatment coordinators expressed concern about new pollutants generated as a result of the 

use of wet air pollution controls on metal finishing operations to comply with air regulations. 

Specifically, chemical additives used in wet air pollution controls may be introduced into facility 

wastewater, which is subsequently sent to POTWs or is discharged directly to surface water.

EPA did not further explore the impact of wet air pollution controls during the 2014 Annual 

Review.

The regional EPA pretreatment coordinators also mentioned the need for hexavalent

chromium limits for metal finishing wastewaters. In the Metal Finishing ELGs, total chromium 

limits are set without any specific limits for the discharge of hexavalent chromium, chromium’s 

more toxic form. The pretreatment coordinators indicated that smaller metal finishing facilities 

generally do not employ chromium reduction operations to reduce hexavalent chromium to its 

less toxic form (i.e., trivalent chromium) if the total chromium limits are met before discharge.

Some POTWs are setting more stringent local limits on hexavalent chromium from metal 

finishing wastewater. Several pretreatment coordinators suggested that EPA consider developing 

limits specific to hexavalent chromium to reduce its potential discharge to POTWs and surface 

water. 

5.1.2.5 Review of Metal Finishing Wastewater Treatment Technologies

In 1983, EPA set BAT and PSES limits to control discharges of toxic metals, toxic 

organics, and cyanide from the Metal Finishing Category. These standards were based on the 

best practicable control technology (BPT) for the industry at that time and include physicalchemical precipitation followed by clarification with additional cyanide oxidation and chromium 

reduction pretreatment steps where these pollutants are present in the wastewater stream (U.S. 

EPA, 1983). This section further discusses the wastewater treatment technologies that are 

prevalent in the industry, as well as advanced treatment technologies and zero-discharge or reuse 

practices that are emerging within the industry for the treatment and/or recycling of metal 

finishing wastewater. 

5.1.2.5.1 Commonly Used Technologies for the Treatment of Metal Finishing Wastewater 

EPA’s review indicates that physical-chemical precipitation, clarification, chromium 

reduction, and cyanide oxidation are prevalent technologies for the treatment of metal finishing 

wastewater. The regional EPA pretreatment coordinators have observed that a vast majority of 

metal finishing operations that treat metal finishing wastewater for discharge can meet the 
Section 5—Continued Review of Select Industrial Categories

5-20 

current Metal Finishing ELGs using these treatment technologies. Industry literature also 

confirms the prevalence of these technologies, with minor modifications to improve the solids 

separation stage. Facilities may also add a filtration/polishing step or replace the flocculation and 

clarification steps with direct microfiltration to improve solids removal (Weber, 2013). 

During the development of the MP&M rule in 2003, EPA identified more advanced 

technologies for reducing metal discharges from metal finishing operations than those used as 

the basis for limitations in the Metal Finishing ELGs. The proposed rule’s technology options for 

the subcategories encompassing the Metal Finishing Category included chemical precipitation 

with clarification, microfiltration, and ion exchange (to target removal of colloidal particles, 

heavy metal particulates, and their hydroxides). 

EPA further reviewed the technologies that are prevalent for the treatment of metal 

finishing wastewater and identified limitations associated with their current application. 

Chromium reduction means reducing the oxidation state of hexavalent chromium to 

trivalent chromium, which is less toxic and more amenable to chemical precipitation and 

clarification. Metal finishing operations using hexavalent chromium generally include a 

chromium reduction pretreatment step prior to chemical precipitation (U.S. EPA, 2000) . Recent 

efforts to replace hexavalent chromium with trivalent chromium in metal finishing operations 

(such as those described in Section 5.1.2.2) would eliminate this pretreatment step; however, 

according to industry literature, trivalent chromium may cause its own problems in wastewater 

treatment. Operations using trivalent chromium may generate chromium complexes in the

wastewater that would require a separate pretreatment step to breakdown these complexes into 

treatable constituents prior to chemical precipitation (Weber, 2013). 

Cyanide oxidation most commonly uses an alkaline chlorination process that treats 

simple cyanides in the process wastewater prior to the chemical precipitation step. Complexed 

cyanides must be treated separately using a high-pressure, high-temperature thermal process. 

Industry sources indicate that complexed cyanides are generally the cause of pretreatment 

violations (Weber, 2013). 

Metal finishing wastewater may contain complexing and chelating agents, which are 

important constituents of some plating operations, especially electroless plating, immersion 

plating, and printed circuit board manufacturing. These agents may also produce metal 

complexes that present a problem for effective metal removal, since they hinder the formation of 

precipitates in the chemical precipitation system (U.S. EPA, 1979; U.S. EPA, 1984). During the 

development of the Metal Finishing ELGs, EPA recommended segregated treatment of the 

complexed metal wastes. Among the proposed technologies were high-pH precipitation to break 

down the complexes and precipitate the metal ions, sulfide precipitation, and ferrous sulfate 

precipitation. In the MP&M proposed rule, EPA identified pretreatment steps to break down the 

chelates using reducing agents such as sodium borohydride, hydrazine, dithiocarbamate 

(measured analytically as ziram), or sodium hydrosulfite; using high-pH precipitation with 

calcium hydroxide or ferrous sulfate addition; or filtering the chelated metals out of solution 

prior to chemical precipitation (U.S. EPA, 2000). EPA is not certain which current technologies 

are most commonly used to treat complexed metal waste from metal finishing operations. 
Section 5—Continued Review of Select Industrial Categories

5-21 

Regional EPA pretreatment coordinators indicate that some smaller facilities can meet 

pretreatment standards without implementing chemical precipitation and clarification treatment 

of metal finishing wastewater. These smaller facilities may generate small volumes of metal 

finishing wastewater for which they can store, monitor, and control the frequency of discharge. 

The smaller facilities may also discharge dilute rinse water, but use other management practices 

for plating baths, such as wastewater disposal at centralized waste treatment facilities or in onsite 

evaporations tanks or they may use advanced closed-loop/reuse practices. The practice of

diluting rinse water as a partial or total substitute for adequate treatment to achieve compliance 

with discharge limits is in violation of the National Pretreatment Standards: Categorical 

Standards (40 CFR Part 403.6(d)). See below for more discussion on advanced closed-loop/reuse 

practices. 

5.1.2.5.2 Emerging Technologies for the Treatment of Metal Finishing Wastewater 

In most cases, the use of chemical precipitation and clarification with optional 

pretreatment of chromium and cyanide has been sufficient to meet the Metal Finishing ELGs. 

However, more advanced treatment technologies are emerging. Based on more recent 

observations from the regional EPA pretreatment coordinators and industry sources, emerging 

technologies are being used to some extent, but are not yet widespread within the industry. 

To identify emerging technologies that are being evaluated and/or implemented, EPA 

reviewed recent literature gathered to develop and populate the Industrial Wastewater Treatment 

Technology (IWTT) database (for more information on the IWTT database, see Section 6.2 of 

this report). A query of the IWTT database produced nine articles with performance data on the 

treatment of metal finishing wastewater. A majority of these articles document the performance 

of pilot-scale systems that facilities are implementing to evaluate treatment performance. Table 

5-10 summarizes these systems’ treatment effectiveness. 

As the table shows, a variety of wastewater treatment technologies (or combinations of 

technologies) have been tested to treat metal finishing wastewater, including electrocoagulation

and membrane bioreactors. These systems target a range of regulated pollutants such as 

cadmium, chromium, nickel, and zinc, as well as non-regulated pollutants such as iron, 

manganese, and tin. The majority of the treatment performance data for these technologies target 

metal removals and show a percent removal of greater than 90 percent, reaching effluent 

concentrations sometimes orders of magnitude below current effluent limitations. 
Section 5—Continued Review of Select Industrial Categories

5-22 

Table 5-10. Summary of Wastewater Treatment Technologies for End-of-Pipe Discharge of Metal Finishing Wastewater

Wastewater 

Treatment

(Order of Unit 

Processes)

Type of Wastewater

Treated

Treatment

Scale (Pilotor FullScale) Metals TreatedEffluent 

Concentration 

(mg/L)

Percent 

Removal

Metal Finishing Monthly 

Average ELG Limit

(40 CFR Part 433)

NSPS/PSNS BAT/PSES Article Source

Adsorptive media Electroplating process 

wastewater

Pilot Chromium, 

hexavalent

Not provided 79 NA NA (Lv, 2013)

Aerobic fixed film 

biological treatment, 

chemical 

precipitation, 

powdered activated 

carbon

Electroplating process 

wastewater

Pilot Chromium,

hexavalent

<0.05 >99.8 NA NA (Ahmad, 2010)

Chromium, total 0.7 98.6 1.71 1.71

Iron 0.2 67.21 NA NA

Manganese 0.15 53.13 NA NA

Tin <0.1 >66.67 NA NA

Zinc 0.02 81.82 1.48 1.48

Biological activated 

filtersa 

Chromium plating 

process wastewater

Pilot Chromium, 

hexavalent

30,000 45.75 NA NA (Colica, 2012)

Electrocoagulation Aircraft maintenance 

operations wastewater 

subject to 40 CFR Part 

433 and 40 CFR Part 

413 effluent limits

Pilot Cadmium 0.012–0.126 75-99.9 0.07 0.26 (Firouzi, 2009a; 

Firouzi, 2009b; 

Firouzi, 2010) 

Chromium 0.031–7.204 84-99.91 1.71 1.71

Nickel 0.022–1.317 65.1-

99.77

2.38 2.38

Electrocoagulation 

followed by 

membrane filtration

Aircraft maintenance 

operations wastewater 

subject to 40 CFR Part 

433 and 40 CFR Part 

413 effluent limits

Pilot Cadmium 0.004 98.58 0.07 0.26 (Firouzi, 2009b)

Chromium 0.018 99.94 1.71 1.71

Nickel 0.07 99.48 2.38 2.38

Flow equalization, 

anaerobic fixed film 

biological treatment, 

aerobic fixed film 

biological treatment

Metal working process 

wastewater

Pilot Not provided Not provided Not 

provided

NA NA (Schuch, 2000)

Liquid extractiona Metal plating 

wastewater

Pilot Chromium, 

hexavalent

0.06 99.50 NA NA (Usinowicz, 

2005) 

Chromium, total 0.72 96.57 1.71 1.71
Section 5—Continued Review of Select Industrial Categories

5-23 

Table 5-10. Summary of Wastewater Treatment Technologies for End-of-Pipe Discharge of Metal Finishing Wastewater

Wastewater 

Treatment

(Order of Unit 

Processes)

Type of Wastewater

Treated

Treatment

Scale (Pilotor FullScale) Metals TreatedEffluent 

Concentration 

(mg/L)

Percent 

Removal

Metal Finishing Monthly 

Average ELG Limit

(40 CFR Part 433)

NSPS/PSNS BAT/PSES Article Source

Membrane bioreactor Barge cleaning 

wastewater

Pilot Copper 0.0105 70.60 2.07 2.07 (Buckles, 2003)

Lead 0.001 77.30 0.43 0.43

Membrane 

bioreactor, aerobic 

digestionb 

Metal fabrication 

process wastewater 

from the automotive 

industry

Pilot and 

Full

Not provided Not provided Not 

provided

NA NA (Sutton, 2001)

NA: Not applicable.

a The article discusses wastewater treatment technology as applicable for end-of-pipe discharge and zero discharge. 

b The article presents treatment information for pollutants such as chemical oxygen demand and oil and grease, but provides no treatment information for 

metals. 
Section 5—Continued Review of Select Industrial Categories

5-24 

5.1.2.5.3 Technologies to Achieve a Zero-Discharge, Closed-Loop Process 

A closed-loop process is a system that treats process wastewater to an acceptable quality 

to be returned back to the process for reuse (Candiloro, 2012). Unwanted contaminants removed 

from the wastewater are disposed of as solid waste; no wastewater is discharged. During the 

development of the MP&M rule EPA identified technology options that included wastewater 

management alternatives such as closed-loop and reuse practices using reverse osmosis and 

evaporation (U.S. EPA, 2000). Recent industry literature also identified technologies to purify 

process wastewater for recycling, which minimizes overall wastewater generation and discharge 

(McLay, 2013). Table 5-11 summarizes these waste minimization technologies and practices 

available to reduce the volume of wastewater discharged from metal finishing operations and to 

recover other process waste streams, such as plating baths, to be reused in the process. 

Table 5-11. Summary of Waste Minimization Technologies for Reuse

Technology Technology Description Types of Wastewater Treated

Evaporation An energy-intensive process of concentrating and 

returning a stream back to process by converting 

some of the liquid to vapor. The only process that can 

treat plating rinse waters back to or beyond original 

strength. 

Plating baths, rinse waters, 

pretreated wastewater (brine for 

disposal)

Reverse osmosis Separation of solutes from solvent using a highpressure differential across a membrane. Limited 

application due to the high pressure requirement to 

overcome the significant osmotic pressure from the 

feed solution. Limited application to nickel plating 

rinsewater because the water returned is at too low a 

concentration to be completely recycled. 

High total dissolved solids 

wastewater, nickel plating 

rinsewater (limited)

Electrodialysis Configuration of stacked ion exchange membranes 

with two electrodes at both ends of the stacks to 

separate desirable compounds across a concentration 

(voltage) gradient with minimal energy consumption. 

Requires careful maintenance and periodic membrane 

regeneration.

Gold, silver, nickel, tincontaining solutions; nickel 

electroplating bath (slow 

circulation process)

Membrane electrolysis Single-membrane process driven by electrolytic 

potential across an ion exchange membrane or 

diaphragm to remove metallic impurities.

Plating, anodizing, etching, 

stripping, and other metalfinishing process solutions, 

chromium plating baths, chrome 

conversion coating solutions

Diffusion dialysis Multi-membrane technology to recover clean acid 

from spent acid solutions using a concentration 

gradient between deionized water and the process 

acid. Also generates an acidic waste stream that 

requires treatment.

Spent acid solutions, 

hydrofluoric/nitric acids, 

sulfuric/nitric and 

sulfuric/hydrochloric acids, 

battery acids

Ion exchange Separation process for removing low concentrations 

of ionic compounds from dilute wastewater. 

Noble metal recovery (including 

gold), chromate baths, rinse 

water
Section 5—Continued Review of Select Industrial Categories

5-25 

Table 5-11. Summary of Waste Minimization Technologies for Reuse

Technology Technology Description Types of Wastewater Treated

Electrowinning Consists of three main components to recover metals 

from electroplating rinse water: an electrolytic cell, a 

rectifier, and a pump. The electrolytic cell is a tank in 

which cathodes and anodes are typically arranged in 

alternating order, attached to their respective bus bars, 

which supply the electrical potential to the unit. 

Electroplating rinse water 

containing gold, silver, copper, 

cadmium, and zinc

Electrodeposition/

electrocoagulation

Metals recovery though cathodic deposition. Types of 

reactors include tank cells, plate and frame cells, 

rotating cells, fluidized beds, packed bed cells, and 

porous carbon packing cells. 

Manganese-phosphate coating 

wastewater; cadmium-, copper-, 

zinc, and hexavalent chromiumcontaining water

Electroflotation A process that floats pollutants to the surface of a 

water body by tiny bubbles of hydrogen and oxygen 

gases generated from water electrolysis. 

Heavy-metal-containing 

wastewaters, gold and silver 

recovered from cyanide solutions

Sources: (Adhoum, 2004; Bloch, 2000; Chen, 2004; Firouzi, 2009a; Ince, 2013; Mahvi, 2007; McLay, 2013; U.S. 

EPA, 2000). 

In addition, EPA identified six articles in a query of the IWTT database that presented 

performance data for the treatment of metal finishing wastewater for reuse. Table 5-12

summarizes the treatment effectiveness of these systems. A majority of the articles document the 

performance of pilot-scale systems that facilities are implementing to evaluate treatment 

performance and the quality of reuse water. As the results show, a variety of technologies (or 

combinations of technologies) have been tested to treat metal finishing wastewater for reuse, 

targeting a range of regulated pollutants such as chromium and nickel, as well as non-regulated 

pollutants such as calcium, magnesium, and sodium. The treatment technologies discussed in 

Table 5-12 do not always result in zero discharge: in some cases, they produce a concentrated 

waste stream that is handled as a hazardous waste.
Section 5—Continued Review of Select Industrial Categories

5-26 

Table 5-12. Summary of Wastewater Treatment Technologies for Reuse of Metal Finishing Wastewater

Wastewater Treatment 

(Order of Unit 

Processes)

Type of Wastewater

Treated

Treatment 

Scale

(Pilot- or 

Full-Scale) Metals Treated

Effluent 

Concentration 

(mg/L)

Percent 

Removal

Metal Finishing Monthly 

Average ELG Limit

(40 CFR Part 433)

NSPS/PSNS BAT/PSES Article Source

Biological activated 

filtersa 

Chromium plating 

process wastewater

Pilot Chromium, 

hexavalent

30,000 45.75 NA NA (Colica, 2012)

Clarification, granularmedia filtration, 

membrane filtration, bag 

and cartridge filtration, 

ultraviolet, reverse 

osmosis

Electroless nickelplating process 

wastewater

Pilot Calcium 0.02 99.90 NA NA (Qin, 2004)

Nickel <0.003 >99.90 2.38 2.38

Sodium 1.45 98.70 NA NA

Flow equalization, ion 

exchange, chemical 

precipitation, membrane 

filtration, reverse 

osmosis, evaporation

Automotive 

components 

manufacturing 

process wastewater

Full Calcium <1 >99.67 NA NA (Chan, 2011)

Magnesium <0.5 >99.8 NA NA

Sodium, total 

(as Na)

<60 >95.00 NA NA

Granular-media filtration, 

bag and cartridge 

filtration, ultraviolet, 

granular activated carbon 

unit, membrane filtration, 

nanofiltration, ion 

exchange

Final rinse process 

wastewater from 

electroless plating 

operations

Pilot Not provided Not provided Not 

provided

NA NA (Wong, 2002)

Liquid extractiona Metal plating 

wastewater

Pilot Chromium, 

hexavalent

0.06 99.50 NA NA (Usinowicz, 

2005) 

Chromium, total 0.72 96.57 1.71 1.71

Membrane filtration Solvent cleaning 

rinse water from 

nickel-plating 

operations

Pilot Not provided Not provided Not 

provided

NA NA (Qin, 2006)

NA: Not applicable.

a The article discusses wastewater treatment technology as applicable for end-of-pipe discharge and zero discharge.

b The article presents treatment information for pollutants such as chemical oxygen demand and oil and grease, but provides no treatment information for 

metals. 
Section 5—Continued Review of Select Industrial Categories

5-27 

EPA regional pretreatment coordinators noted they have observed that smaller facilities, 

with smaller volumes of wastewater, can achieve zero discharge by implementing cost-effective 

alternatives. These alternatives include technologies such as evaporation tanks, which combined 

with storage and reuse, eliminate wastewater discharges. A 2008 study observed an increasing 

trend towards wastewater minimization practices during metal finishing operations at both small 

and large facilities throughout the industry (Chalmer, 2008). Larger facilities may use some of 

these practices, but because of the larger volumes of water used, they may not completely 

eliminate discharges. The extent of the use of the technologies identified in Table 5-11 is 

unknown. 

5.1.3 Potential ELG Applicability Issues and Other Considerations 

As part of the 2014 Annual Review, EPA discussed with regional EPA pretreatment 

coordinators any noticeable changes to the metal finishing industry over time and whether those 

changes may be impacting the POTW treatability of metal finishing wastewater. The regional 

pretreatment coordinators indicated that they have not encountered recent issues with POTW 

treatability of metal finishing wastewater; this includes issues involving nickel, chromium, and 

zinc, which were identified as pollutants of concern in the 2012 Annual Review (U.S. EPA, 

2014a). 

However, the regional pretreatment coordinators provided observations on issues arising 

from the implementation of the Metal Finishing ELGs. They noted some key topic areas for 

EPA’s consideration: 

• Misapplication of the limits in permit applications. Unlike other metal-related 

industries (e.g., aluminum forming, iron and steel), the Metal Finishing ELGs are 

concentration-based and are easier to apply in wastewater permits than the 

production-based standards. As a result, the regional pretreatment coordinators 

have observed the application of the Metal Finishing ELGs for wastewater 

generated from operations that should be regulated by other ELGs. Additionally, 

the pretreatment coordinators noted that POTWs may still be implementing 40 

CFR Part 413 pretreatment standards for metal finishing wastewater. Most metal 

finishing facilities should be covered by 40 CFR Part 433 pretreatment standards, 

not 40 CFR Part 413 standards. The scope of facilities still regulated under 40 

CFR Part 413 should be limited to job shops and IPCB manufacturers that were 

considered existing at the time of the 1983 promulgation of the Metal Finishing 

ELGs. 

• Applicability of the 46 metal finishing unit operations. The regional pretreatment 

coordinators also noted that there is uncertainty about the applicability of the 

existing ELGs and how to determine which of the 46 metal finishing operations 

listed in the 1983 Metal Finishing ELGs would apply to current industry 

practices, including: 

• Whether using acid for cleaning and preparing metal surfaces prior to metal 

finishing would constitute “acid cleaning” or “acid etching”;
Section 5—Continued Review of Select Industrial Categories

5-28 

• When the use of phosphoric acid or chromic acid constitutes “cleaning” and when 

it is “conversion coating”; 

• Whether the use of brighteners during cleaning would be considered “acid 

cleaning” or “bright dipping,” which is identified in the Metal Finishing ELGs as 

a form of etching; and 

• How the rule applies to new processes and process chemistries. 

• New source criteria development. The Metal Finishing ELGs identify new 

sources as new sites that are discharging wastewater. Pretreatment coordinators 

suggested that additional guidance is needed to specify the criteria for identifying 

new sources. Existing facilities that develop new or revise existing processes 

question whether certain process changes classify them as new sources. Similarly, 

ACWA commented that a facility covered under the PSES for the Electroplating 

Category (40 CFR Part 413) may upgrade its plant incrementally, which makes it 

difficult to determine when the plant is a new source and subject to the Metal 

Finishing ELGs (40 CFR Part 433) (ACWA, 2013). Additionally, metal finishing 

operations have expanded to product markets that did not exist during the 

development of the ELGs. Pretreatment coordinators noted products such as solar 

panels and cell phone screens as newer metal finishing applications that require 

interpretation as to their applicability under the Metal Finishing ELGs. 

5.1.4 Summary of Findings from EPA’s Continued Review of the Metal Finishing Category 

Based on EPA’s continued preliminary category review, the Metal Finishing Category 

has not experienced significant growth in the last 30 years. However, an industry source suggests 

that the industry is consolidating into larger companies that tend to compete better with the 

expanding global market; this consolidation may have slightly reduced the size of the U.S. metal 

finishing industry (Chalmer, 2008). 

Discussions with regional EPA pretreatment coordinators and a review of literature on 

existing process technologies and advances in wastewater treatment show that a portion of the 

industry is employing new technologies. These new technologies include improved technologies 

for reusing baths and other metal finishing chemicals that reduce the quantities of pollutants 

discharged. The new technologies also include improved wastewater treatment technologies that 

reduce the concentration of pollutants in treated metal finishing wastewater. Implementation of 

these new technologies results in effluent concentrations that are well below the limits 

established in the Metal Finishing ELGs. However, the regional pretreatment coordinators 

reported that despite the emergence of these new technologies, a majority of the industry seems 

to be continuing to meet the ELGs using common treatment technologies (described in Section 

5.1.2.5). Further, they have not observed any notable issues with pass-through or interference at 

POTWs receiving metal finishing wastewater, which would indicate that the industry can 

achieve pretreatment standards for the nine pollutants currently regulated in the Metal Finishing 

ELGs even with the change in surface finishing chemistries over the past three decades.
Section 5—Continued Review of Select Industrial Categories

5-29 

At the time the existing ELGs were developed, metal finishers used base metals such as 

aluminum, magnesium, iron, and tin. In addition to those metals, they are now using metals such 

as titanium, zirconium, vanadium, and also nanocomposites. Metal finishers are also employing 

alternative metal finishing processes and chemicals. These changes may introduce additional 

pollutants into metal finishing wastewater that EPA did not consider in the development of the 

1983 Metal Finishing ELGs. 

EPA’s continued review of the Metal Finishing Category identified several topics that 

require further review: 

• Potential new pollutants of concern not currently regulated, including transition 

metal coatings and nanoscale particles that are becoming more common in metal 

finishing operations. 

• The characteristics of current metal finishing wastewater discharges, including: 

— The need for hexavalent chromium limits in addition to total chromium 

limits to explicitly limit the discharge of the more toxic form of 

chromium. 

— Treatment technologies available for metal finishing wastewater and the 

more stringent discharge concentrations these technologies can achieve. 

• The prevalence of and the potential pollutants of concern associated with 

wastewater generated from the use of wet air pollution control devices, which 

may contribute additional pollutants to metal finishing wastewater.

• The need for clarifying descriptions of metal finishing operations listed in the

ELGs to help permit writers properly apply the Metal Finishing ELGs, 

specifically:

— Providing guidance to help distinguish between metal finishing operations, 

such as etching and chemical milling, acid cleaning, chemical conversion 

coating, and similar cases in which the same acid is used for different 

functions. 

— Clarifying how the Metal Finishing ELGs apply to current industry 

practices (i.e., practices that evolved after the promulgation of the Metal 

Finishing ELGs) that may use chemical alternatives (e.g., alternatives to 

hexavalent chromium, phosphate-free formulations) and are not 

specifically identified in the ELGs.

— Clarifying applicability of the Metal Finishing ELGs to newer 

manufacturing operations that use metal finishing, such as solar panel 

manufacturing and cell phone manufacturing. 

• How advanced wastewater treatment technologies are used and the prevalence of 

zero discharge practices in the industry.
Section 5—Continued Review of Select Industrial Categories

5-30 

5.1.5 References for the Continued Review of the Metal Finishing Category

1. ACWA, 2013. Association of Clean Water Administrators. Public Comment Submitted 

by the Association of Clean Water Administrators on the Preliminary 2012 Effluent 

Guidelines Program Plan. Re: Docket ID No. EPA-HQ-OW-2010-0824/Preliminary 2012 

Effluent Guidelines Program Plan and 2011 Annual Effluent Guidelines Review Report. 

(October 7). EPA-HQ-OW-2010-0824-0218-A2. 

2. Adhoum, N. L. Monser, N. Belakal, and J-E Belgaied. 2004. Treatment of electroplating 

wastewater containing Cu2+, Zn2+ and Cr(vi) by electrocoagulation. Journal of 

Hazardous Materials. B112: 207-213. EPA-HQ-OW-2014-0170. DCN 08004. 

3. Ahmad, W.A. Z.A. Zakaria, A.R. Khasim, M.A. Alias, and S.M.H.S. Ismail. 2010. Pilotscale removal of chromium from industrial wastewater using the chromebac system. 

Bioresource Technology. 101 (12): 4371-4378. (June). EPA-HQ-OW-2014-0170. DCN 

08005. 

4. Bloch, L. 2000. Metal recovery and wastewater reduction using electrowinning. Products 

Finishing. (January 1). Available online at: http://www.pfonline.com/articles/metalrecovery-and-wastewater-reduction-using-electrowinning. EPA-HQ-OW-2014-0170. 

DCN 08007. 

5. Buckles, J. A. Kuljian, K. Olmstead, and J. Merritt. 2003. Treatment of oily wastes by 

membrane biological reactor. Water Environment Federation's 2003 Technical Exibition 

and Conference. Los Angeles, CA. (October 11-15). EPA-HQ-OW-2014-0170. DCN 

08008. 

6. Candiloro, S. 2012. Close loop for zero waste water discharge, Epner Technology Inc. 

(May 17). EPA-HQ-OW-2014-0170. DCN 08009. 

7. Chalmer, P. 2008. The future of finishing. National Center for Manufacturing Services.

(January 1). EPA-HQ-OW-2014-0170. DCN 08010. 

8. Chan, M. 2011. Recovery and recycling of industrial side-stream wastewater. 

International Water Conference. Orlando, FL. (November 13-17). EPA-HQ-OW-2014-

0170. DCN 08011. 

9. Chen, G. 2004. Electrochemical technologies in wastewater treatment. Separation and 

Purification Technology. 38: 11-41. (January 1). EPA-HQ-OW-2014-0170. DCN 08012. 

10. Colica, G. P.C. Mecarozzi, and R. DePhilippis. 2012. Biosorption and recovery of 

chromium from industrial wastewaters by using saccharomyces cerevisiae in a flowthrough system. Industrial & Engineering Chemistry Research. 51 (11): 4452-4457. 

(March 8). EPA-HQ-OW-2014-0170. DCN 08013. 

11. Dennis, R. L.T. Viyannalage, A.V. Gaikwad, T.K. Rout, and S. Banerjee. 2014. 

Graphene nanocomposite coatings for protecting low-alloy steels from corrosion. 
Section 5—Continued Review of Select Industrial Categories

5-31 

American Ceramic Society Bulletin. 92 (5): 18-24. EPA-HQ-OW-2014-0170. DCN 

08014. 

12. Dunham, B. D. Chalk. 2013. Non-phosphate transition metal coatings, 81st universal 

metal finishing guidebook. Metal Finishing Magazine. 111 (7): 116-122. (Fall). 

(September 1). EPA-HQ-OW-2014-0170. DCN 08015. 

13. Firouzi, F. M.A. Ross, G. Champneys and M.J. McFarland. 2009a. Treatment of metal 

finishing wastewater from aircraft maintenance operations using an electrocoagulation 

treatment process. Microconstituents and Industrial Water Quality. 8: 473-480. EPAHQ-OW-2014-0170. DCN 08017. 

14. Firouzi, F. M.A. Ross, G. Champneys and M.J. McFarland. 2009b. Treatment of metal 

finishing wastewaters in the presence of chelating substances. Water Environment 

Federation's 2009 Technical Exibition and Conference. Orlando, FL. (October 10-14). 

EPA-HQ-OW-2014-0170. DCN 08018. 

15. Firouzi, F. M.A. Ross, G. Champneys and M.J. McFarland. 2010. Needs more work. 

Industrial Wastewater. 10-12. (April/May). EPA-HQ-OW-2014-0170. DCN 08019. 

16. Hopwood, D. 2012. Zirconium pretreatments: Not just for early adopters anymore. Metal 

Finishing: The Plating and Coating Industries’ Technology Magazine. 110 (6): 18-21. 

(July/August). EPA-HQ-OW-2014-0170. DCN 08021. 

17. Ince, M. 2013. Treatment of manganese-phosphate coating wastewater by 

electrocoagulation. Separation Science and Technology. 48: 515-522. (January 18). EPAHQ-OW-2014-0170. DCN 08023. 

18. LaFlamme, D. 2009. Going low-temp. Products Finishing. (January 1). Available online 

at: http://www.pfonline.com/articles/going-low-temp. EPA-HQ-OW-2014-0170. DCN 

08025. 

19. Legg, K. n.d. Rowan Technology Group. Chrome replacements for internals and small 

parts. Available online at: http://www.asetsdefense.org/documents/DoDReports/Cr_Plating_Alts/Cr_Rplcmnt-IDs&Sm_Parts.PDF. EPA-HQ-OW-2014-0170. 

DCN 08026. 

20. Lv, X. Z. Chen, Y. Wang, F. Huang, and Z. Lin. 2013. Use of high-pressure CO2 for 

concentrating CrVI from electroplating wastewater by Mg-Al layered double hydroxide. 

Applied Materials & Interfaces. 5 (21): 11271-11275. (October 1). EPA-HQ-OW-2014-

0170. DCN 08027. 

21. Mahvi, A.H. E. Bazrafshan. 2007. Removal of cadmium from industrial effluents by 

electrocoagulation process using aluminum electrodes. World Applied Sciences Journal.

2 (1): 34-39. EPA-HQ-OW-2014-0170. DCN 08028. 

22. Manavbasi, A. 2012. Non-chromated conversion coating for magnesium alloys and zincnickel plated steel. Products Finishing. (November 13). Available online at: 
Section 5—Continued Review of Select Industrial Categories

5-32 

http://www.pfonline.com/articles/non-chromated-conversion-coating-for-magnesiumalloys-and-zinc-nickel-plated-steel. EPA-HQ-OW-2014-0170. DCN 08029. 

23. McLay, W.J. 2013. Waste minimization and recovery technologies, 81st universal metal 

finishing guidebook. Metal Finishing Magazine. 111 (7): 595-619. (Fall). (September 1). 

EPA-HQ-OW-2014-0170. DCN 08030. 

24. Ogundiran, O. 2011. A Study of Zinc-Nickel as an Alternate Coating to Cadmium for 

Electrical Connector Shells Used in Aerospace Applications. A Thesis Submitted to the 

Graduate Faculty of Rensselaer Polytechnic Institute. (April). EPA-HQ-OW-2014-0170. 

DCN 08032. 

25. Qin, J-J. M.N. Wai, M.H. Oo, and H. Lee. 2004. A pilot study for reclamation of a 

combined rinse from a nickel-plating operation using a dual-membrane UF/RO process. 

Desalination. 161 (2): 155-167. (February 20). EPA-HQ-OW-2014-0170. DCN 08033. 

26. Qin, J-J. M.H. Oo and F.S. Wong. 2006. Pilot study on the treatment of spent solvent 

cleaning rinse in metal plating. Desalination. 191: 359-364. (May 10). EPA-HQ-OW2014-0170. DCN 08034. 

27. Schuch, R. R. Gensicke, K. Merkel, and J. Winter. 2000. Nitrogen and DOC removal 

from wastewater streams of the metal-working industry. Water Research. 34 (1): 295-

303. (January). EPA-HQ-OW-2014-0170. DCN 08037. 

28. Sutton, P.M. P. Mishra, J. Roberts, L. Abreu, and P. Gignac. 2001. Optimization of oily 

wastewater membrane bioreactor treatment: Pilot to full scale results. Water 

Environment Federation's 2001 Technical Exposition and Conference. Atlanta, GA. 

(October 13-17). EPA-HQ-OW-2014-0170. DCN 08038. 

29. U.S. EPA. 1979. Development Document for Existing Source Pretreatment Standards for 

the Electroplating Point Source Category. Washington, D.C. (August). EPA-HQ-OW2014-0170-0007. 

30. U.S. EPA. 1981. Federal Register Notice: Effluent Guidelines and Standards; 

Electroplating Point Source Category Pretreatment Standards for Existing Sources. 

Washington, D.C. (January). EPA-HQ-OW-2014-0170. DCN 08039. 

31. U.S. EPA. 1983. Development Document for Effluent Limitations Guidelines and New 

Source Performance Standards for the Metal Finishing Point Source Category. 

Washington, D.C. (June). EPA-HQ-OW-2004-0032-0110. 

32. U.S. EPA. 1984. Guidance Manual for Electroplating and Metal Finishing Pretreatment 

Standards. Washington, D.C. (February). EPA-HQ-OW-2014-0170. DCN 08040. 

33. U.S. EPA. 2000. Development Document for the Proposed Effluent Limitations 

Guidelines and Standards for the Metal Products & Machinery Point Source Category. 

Washington, D.C. (December). EPA-HQ-OW-2014-0170-0005. 
Section 5—Continued Review of Select Industrial Categories

5-33 

34. U.S. EPA. 2009. Technical Support Document for the Annual Review of Existing Effluent 

Guidelines and Identification of Potential New Point Source Categories. Washington, 

D.C. (October). EPA-821-R-09-007. EPA-HQ-OW-2008-0517-0515. 

35. U.S. EPA. 2012. The 2011 Annual Effluent Guidelines Review Report. Washington, D.C. 

(December). EPA-821-R-12-001. EPA-HQ-OW-2010-0824-0195. 

36. U.S. EPA. 2013. EPA Small Business Innovation Research (SBIR) Program. 2013 

Presidential Green Chemistry Award Winner – Faraday Technology, Inc. Functional 

Trivalent Chromium Plating Process to Replace Hexavalent Chromium Plating. 

Available online at: http://www.epa.gov/ncer/sbir/success/pdf/faraday_success.pdf. EPAHQ-OW-2014-0170. DCN 08041. 

37. U.S. EPA. 2014a. The 2012 Annual Effluent Guidelines Review Report. Washington, 

D.C. (September). EPA-821-R-14-004. EPA-HQ-OW-2010-0824-0320. 

38. U.S. EPA. 2014b. The 2013 Annual Effluent Guidelines Review Report. Washington, 

D.C. (September). EPA-821-R-14-003. EPA-HQ-OW-2014-0170-0077. 

39. Usinowicz, P.J. B.F. Monzyk, H.N. Conkle, J.K. Rose, and S.P. Chauhan. 2005. The use 

of liquid-liquid extraction for heavy metals recovery and reuse from plating wastewaters. 

Water Environment Federation's 2005 Technical Exposition and Conference. Washington 

D.C. (October 30 - November 2). EPA-HQ-OW-2014-0170. DCN 08042. 

40. Weber, T. 2013. Wastewater treatment, 81st universal metal finishing guidebook. Metal 

Finishing Magazine. 111 (7): 582-594. (Fall). (September 1). EPA-HQ-OW-2014-0170. 

DCN 08043. 

41. Wolterbeek, M. 2012. New coating for aluminum developed to replace cancer-causing 

product. Nevada Today. University of Nevada, Reno. EPA-HQ-OW-2014-0170. DCN 

08044. 

42. Wong, F.S. J.-J. Qin, M.N. Wai, A.L. Lim, and M. Adiga. 2002. A pilot study on a 

membrane process for the treatment and recycling of spent final rinse water from 

electroless plating. Separation and Purification Technology. 29 (1): 41-51. (October). 

EPA-HQ-OW-2014-0170. DCN 08045.
Section 5—Continued Review of Select Industrial Categories

5-34 

5.2 Targeted Review of Pesticide Active Ingredients Without Pesticide Chemical 

Manufacturing Effluent Limits (40 CFR Part 455) 

As part of the 2012 Annual Review, EPA reviewed analytical methods it had recently 

developed or revised to facilitate its identification of unregulated pollutants in industrial 

wastewater discharges. This review included the EPA Office of Water’s 2012 updates to the test 

procedures for analysis of pollutants under the Clean Water Act (CWA) (2012 Method Update 

Rule) (77 FR 29758). Under the authority of the CWA, EPA publishes laboratory methods at 40 

CFR Part 136 (U.S. EPA, 2012a). Industries and municipalities use these methods to analyze the 

chemical, physical, and biological properties of wastewater and other environmental samples that 

require measurement by regulation. As part of the 2012 Method Update Rule, EPA added some 

of the methods for pesticide active ingredients (PAIs) from Table IG in Part 136 to applicable 

parameters listed in Table ID for general use. EPA reviewed these methods and identified 30 

PAIs (listed below in Table 5-13) that are measured by existing analytical methods listed in 40 

CFR Part 136, but discharges of which from manufacturers are not currently regulated under the 

Pesticide Chemicals effluent limitation guidelines and standards (ELGs) (40 CFR Part 455) (U.S. 

EPA, 2014a). 

The Pesticide Chemicals ELGs regulate wastewater discharges from four subcategories:

1. Subpart A: Organic Pesticide Chemicals Manufacturing;

2. Subpart B: Metallo-Organic Pesticide Chemicals Manufacturing;

3. Subpart C: Pesticide Chemicals Formulating and Packaging; and

4. Subpart E: Repackaging of Agricultural Pesticides Performed at Refilling 

Establishments.

EPA established specific limitations for the discharge of PAIs from pesticide chemicals 

manufacturing under Subparts A and B in Tables 2 and 3 of 40 CFR Part 455. EPA also 

established specific limitations for discharge of PAIs from pesticide formulating, packaging, and 

repackaging (PFPR) under Subparts C and E. The PAIs with limitations under Subparts C and E 

are limited to zero discharge unless the facility decides to incorporate certain pollution 

prevention alternative practices (see Table 10 in 40 CFR Part 455). For the purposes of this 

review, EPA is focusing on the list of 30 PAIs of interest (listed below in Table 5-13) as they 

relate to Subparts A and B. 

The Pesticide Chemicals ELGs regulate PAIs, but several other terms can refer to 

pesticides. The ELG defines these terms as:

1. Pesticide: any substance or mixture of substances intended for preventing, 

destroying, repelling, or mitigating any pest.

2. Active ingredient: an ingredient of a pesticide that is intended to prevent, destroy, 

repel, or mitigate any pest.

3. Pesticide chemicals: the sum of all active ingredients manufactured at each 

facility covered by 40 CFR Part 455. 
Section 5—Continued Review of Select Industrial Categories

5-35 

4. Formulation of pesticide products: the process of mixing, blending, or diluting 

one or more PAIs with one or more active or inert ingredients, without an 

intended chemical reaction to obtain a manufacturing use product or an end use 

product. 

For the 2014 Annual Review, EPA began investigating whether U.S. manufacturers 

produced the 30 PAIs of interest, listed in Table 5-13, and whether these ingredients may be 

present in industrial wastewater discharges from pesticide chemical manufacturing. For 

reference, Table 5-13 also indicates whether each PAI is regulated under Subparts C and E in the 

Pesticide Chemicals ELGs (discharges are prohibited under Subparts C and E unless certain 

pollution prevention alternatives are employed). As previously stated, EPA is focusing these 30 

PAIs as they relate to Subparts A and B.

Table 5-13. PAIs Measured by EPA-Approved Methods Without Limits in Subparts A 

and B of the Pesticide Chemicals ELGs (40 CFR Part 455)

EPA 

Method Chemical CAS Number

Limitations Under 

Subparts A and B in 40 

CFR Part 455?

Limitations Under 

Subparts C and E in 40 

CFR Part 455?a 

608.1 Chlorobenzilate 510-15-6 No Yes

Chloropropylate 5836-10-2 No No

Dibromochloropropane 96-12-8 No No

Etridiazole 2593-15-9 No Yes

614.1 EPN 2104-64-5 No Yes

615 Dalapon 75-99-0 No Yes

617 Carbophenothion 786-19-6 No Yes

Endosulfan sulfate 1031-07-8 No No

Endrin aldehyde 7421-93-4 No No

Heptachlor epoxide 1024-57-3 No No

Isodrin 465-73-6 No No

Strobane 8001-50-1 No No

619 Atraton 1610-17-9 No No

Secbumeton 26259-45-0 No No

Simetryn 1014-70-6 No No

622 Chlorpyrifos methyl 5598-13-0 No Yes

Coumaphos 56-72-4 No Yes

Ethoprop 13194-48-4 No Yes

Ronnel 299-84-3 No Yes

Tokuthion 34643-46-4 No No

Trichloronate 327-98-0 No No

622.1 Aspon 3244-90-4 No Yes

Dichlofenthion 97-17-6 No No

Famphur 52-85-7 No Yes

Fenitrothion 122-14-5 No Yes
Section 5—Continued Review of Select Industrial Categories

5-36 

Table 5-13. PAIs Measured by EPA-Approved Methods Without Limits in Subparts A 

and B of the Pesticide Chemicals ELGs (40 CFR Part 455)

EPA 

Method Chemical CAS Number

Limitations Under 

Subparts A and B in 40 

CFR Part 455?

Limitations Under 

Subparts C and E in 40 

CFR Part 455?a 

Fonophos 944-22-9 No No

Thionazin 297-97-2 No No

632 Fluometuron 2164-17-2 No Yes

Neburon 555-37-3 No Yes

Oxamyl 23135-22-0 No Yes

Source: 40 CFR Part 455, 2012 Method Update Rule (77 FR 29758). a Limits under Subparts C and E are zero discharge unless the facility decides to incorporate pollution prevention 

alternative practices (see Table 10 in 40 CFR Part 455). 

5.2.1 Targeted Review of Pesticide Active Ingredients Without Pesticide Chemical 

Manufacturing Effluent Limits 

To determine if U.S. manufacturers are producing the 30 PAIs of interest and identify if 

they are present in industrial wastewater discharges from pesticide chemicals manufacturing, 

EPA’s Office of Water contacted EPA’s Office of Pesticide Programs (OPP) to review the 

registration status for each active ingredient. Section 3 of the Federal Insecticide, Fungicide, and 

Rodenticide Act (FIFRA) governs pesticide registration and provides the authority to regulate the 

content and labeling of pesticide products (U.S. EPA, 2012b). Registration is required when a 

pesticide product is produced in the U.S. for distribution, sale, or use within the U.S. (Keigwin, 

R., 2014). The pesticide product may contain PAIs (U.S. EPA, 2014b). 

FIFRA Section 4 requires that pesticide product registrations be reviewed every 15 years 

and requires EPA to reregister all pesticide products that were registered before 1984 in order to 

update labeling and use requirements. EPA may cancel a registration if it determines that the 

pesticide product does not comply with any of the FIFRA requirements. After cancellation, any 

production of the pesticide product for distribution, sale, or use within the U.S. is prohibited 

(U.S. EPA, 2012b). OPP provided the registration status for each of the 30 PAIs of interest, 

shown in Table 5-14 (Keigwin, R., 2014). 

Table 5-14. Registration Status for the 30 PAIs of Interest

EPA Method Chemical CAS Number Registration Status

608.1 Chlorobenzilate 510-15-6 All U.S. registrations have been canceled.

Chloropropylate 5836-10-2 All U.S. registrations have been canceled.

Dibromochloropropane 96-12-8 Never registered in the U.S.

Etridiazole 2593-15-9 First registered in 1962; under registration review.

614.1 EPN 2104-64-5 All U.S. registrations have been canceled. 

615 Dalapon 75-99-0 All U.S. registrations have been canceled.

617 Carbophenothion 786-19-6 All U.S. registrations have been canceled.

Endosulfan sulfate 1031-07-8 Never registered in the U.S.
Section 5—Continued Review of Select Industrial Categories

5-37

Table 5-14. Registration Status for the 30 PAIs of Interest

EPA Method Chemical CAS Number Registration Status

Endrin aldehydea 7421-93-4 Never registered in the U.S. All U.S. registrations of 

the parent compound, endrin, have been canceled.

Heptachlor epoxideb 1024-57-3 Never registered in the U.S. All U.S. registrations of 

the parent compound, heptachlor, have been canceled.

Isodrin 465-73-6 Never registered in the U.S.

Strobane 8001-50-1 All U.S. registrations have been canceled.

619 Atraton 1610-17-9 Never registered in the U.S.

Secbumeton 26259-45-0 Never registered in the U.S.

Simetryn 1014-70-6 Never registered in the U.S.

622 Chlorpyrifos methyl 5598-13-0 First registered in 1985; under registration review.

Coumaphos 56-72-4 First registered in 1958; under registration review.

Ethoprop 13194-48-4 First registered in 1967; under registration review.

Ronnel 299-84-3 All U.S. registrations have been canceled.

Tokuthion 34643-46-4 Never registered in the U.S.

Trichloronate 327-98-0 Never registered in the U.S.

622.1 Aspon 3244-90-4 All U.S. registrations have been canceled.

Dichlofenthion 97-17-6 All U.S. registrations have been canceled.

Famphur 52-85-7 All U.S. registrations have been canceled.

Fenitrothion 122-14-5

First registered in 1975; under registration review. Only 

product registered in the U.S. is for formulating other 

insecticides. No end-use products registered in the U.S.

Fonofos 944-22-9 All U.S. registrations have been canceled.

Thionazin 297-97-2 All U.S. registrations have been canceled.

632 Fluometuron 2164-17-2 First registered in 1974; under registration review.

Neburon 555-37-3 All U.S. registrations have been canceled.

Oxamyl 23135-22-0 First registered in 1974; under registration review. 

Source: (Keigwin, R., 2014). a Endrin aldehyde has never been a registered pesticide, but is an impurity and breakdown product of a previously 

registered pesticide, endrin. Endrin is also a regulated PAI under the Pesticide Chemicals ELGs (40 CFR Part 

455).

b Heptachlor epoxide has never been a registered pesticide, but is a metabolite of a previously registered 

pesticide, heptachlor. Heptachlor is also a regulated PAI under the Pesticide Chemicals ELGs (40 CFR 

Part 455). 

Although FIFRA Section 3 provides authority to regulate the content and labeling of 

pesticide products through registration, it does not provide the authority to regulate pesticide 

production or production facilities. Manufacturers can only produce pesticide products in the 

U.S. for distribution within the U.S. or for export. As stated above, pesticide products 

manufactured for distribution within the U.S. require registration. However, pesticide products 

manufactured solely for export do not require U.S. registration. Therefore, the registration status 

of a particular PAI (e.g., canceled, never registered) may not indicate which pesticide products 

are produced in the U.S., especially if produced only for export (Keigwin, R., 2014). 
Section 5—Continued Review of Select Industrial Categories

5-38 

Under FIFRA Section 7, establishments producing pesticides, PAIs, or devices must 

register with the appropriate EPA Regional office and report the types and amounts of pesticide 

products they produce. This includes facilities manufacturing pesticide products solely for export 

(Keigwin, R., 2014; U.S. EPA, 2012b). The FIFRA Section 7 data are compiled in the Pesticide 

Registration Information System (PRISM), Section Seven Tracking System (SSTS). The SSTS 

database contains the following information, which may be useful for determining whether any 

of the 30 PAIs of interest are produced in the U.S. (U.S. EPA, 2013): 

1. General establishment and company information (name, contact information); 

2. Product registration status and information; 

3. Product name (common brand names, alternate brand names); 

4. Product classification (e.g., insect repellant, herbicide, rodenticide); 

5. Product type (technical formulation or active ingredient, end-use product, 

repackaged or relabeled, device);

6. Market status in the U.S. (marketed in the U.S., marketed in the U.S. and 

exported, solely exported); 

7. “Restricted Use” pesticide status;

8. Amount produced; 

9. Amount sold or distributed in the U.S.; 

10. Amount sold or distributed to foreign markets; and 

11. Amount estimated to be produced in the following year. 

5.2.2 Summary of Findings from EPA’s Targeted Review of Pesticide Active Ingredients 

Without Pesticide Chemical Manufacturing Effluent Limits 

EPA’s review identified that only seven of the 30 PAIs of interest are currently registered 

or are under registration review in accordance with FIFRA Section 3. The remaining 23 have 

either never been registered or had their registrations canceled. However, discussions with OPP 

suggest that registration status may not be an indicator of whether the PAI is produced in the 

U.S. (and potentially present in industrial wastewater discharge), as unregistered pesticides may 

still be produced in the U.S. for export. Therefore, EPA was not at this time able to prioritize for 

further review a subset of the PAIs of interest that are produced in the U.S. However, EPA did 

identify follow up questions and types of information that will indicate which of the 30 PAIs of 

interest are produced in the U.S. and are thus potentially present in industrial wastewater 

discharges. These sources of information include examining the SSTS production data in 

conjunction with reviews of permit applications, fact sheets, and permits for the facilities that 

produce the PAIs of interest. The information will help EPA answer the following questions and 

determine whether revisions to the Pesticide Chemicals ELGs are warranted: 

• Are any of the 30 PAIs of interest produced in the U.S.? If so, which facilities 

produce the PAIs? 

• What is the manufacturing process of the PAIs at a particular facility?

• Does the manufacturing process of the PAIs produce a wastewater discharge?
Section 5—Continued Review of Select Industrial Categories

5-39 

• Are the PAIs at treatable concentrations in the wastewater discharge?

• Are discharge data available for the PAIs?

• Does the permit have any limitations for the PAIs?

• Is permitting support necessary for plants identified as likely discharging the 

PAIs? 

5.2.3 References for EPA’s Targeted Review of Pesticide Active Ingredients Without 

Pesticide Chemical Manufacturing Effluent Limits

1. Keigwin, R. 2014. Email Communication Between Richard Keigwin, U.S. EPA Office of 

Pesticide Programs, and William Swietlik, U.S. EPA Office of Water. Re: Questions for 

OPP About Pesticides. (April 30). EPA-HQ-OW-2014-0170. DCN 07996. 

2. U.S. EPA. 2012a. Clean Water Act Analytical Methods. Available online at: 

http://water.epa.gov/scitech/methods/cwa/index.cfm. EPA-HQ-OW-2010-0824. DCN 

07746. 

3. U.S. EPA. 2012b. Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). 

Washington, D.C. . (March 30). Available online at: 

http://www.epa.gov/agriculture/lfra.html. EPA-HQ-OW-2014-0170. DCN 07997. 

4. U.S. EPA. 2013. Instructions for Completing EPA Form 3540-16 Pesticide Report for 

Pesticide-Producing and Device-Producing Establishments, Reporting Year 2013. 

Available online at: 

http://www.epa.gov/compliance/resources/publications/monitoring/fifra/estabreportinst.p

df. EPA-HQ-OW-2014-0170. DCN 07998. 

5. U.S. EPA. 2014a. The 2012 Annual Effluent Guidelines Review Report. Washington, 

D.C. (September). EPA-821-R-14-004. EPA-HQ-OW-2010-0824-0320. 

6. U.S. EPA. 2014b. Pesticide Registration Manual: Chapter 1: Overview of Requirements 

for Pesticide Registration and Registrant Obligations. (June 26). Available online at: 

http://www2.epa.gov/pesticide-registration/pesticide-registration-manual-chapter-1-

overview-requirements-pesticide. EPA-HQ-OW-2014-0170. DCN 07999. 
Section 5—Continued Review of Select Industrial Categories

5-40 

5.3 Continued Review of Brick and Structural Clay Products Manufacturing

As part of the 2012 Annual Review, EPA reviewed air quality regulations, including New 

Source Performance Standards (NSPS) and National Emission Standards for Hazardous Air 

Pollutants (NESHAP), to determine if they result in the generation of unregulated wastewater 

discharges or changes to currently regulated wastewater streams (containing new pollutants of 

concern) (U.S. EPA, 2014). From that review, EPA identified brick and structural clay products 

manufacturing as an industry that is not currently regulated by effluent limitations guidelines 

(ELGs) and that may have industrial wastewater discharges resulting from air pollution control 

requirements. 

The brick and structural clay products production process consists of preparing the raw 

materials (primarily clay and shale), forming the processed materials into bricks or other shapes, 

and drying and frying the bricks and shapes (U.S. EPA, 2005). During its review of this industry 

sector in 2012 (U.S. EPA, 2014), EPA identified 93 facilities associated with brick and structural 

clay products manufacturing Standard Industrial Classification (SIC) codes15 reporting discharge 

monitoring report (DMR) data in 2009. Only 37 of the facilities had reported pollutant 

discharges greater than zero. However, none of the facilities holds an individual National 

Pollutant Discharge Elimination System (NPDES) permit; all reported discharges were 

associated with general stormwater permits. 

Because a majority of the brick and structural clay manufacturers reporting DMR data in 

2009 were in Alabama, EPA contacted the Alabama Department of Environmental Management 

(ADEM). The ADEM contact stated that the brick manufacturing facilities have general permits 

for stone, glass, and clay that cover stormwater discharges; they do not have individual NPDES 

permits (Warren, L., 2012). The 2012 review suggested that brick and structural clay products 

manufacturers may have only stormwater discharges, and may not have wastewater discharges 

associated with manufacturing or wet air pollution control systems. However, EPA continued its 

review of the brick and structural clay products manufacturing industry because the evaluation of 

2009 data may not have fully captured the potential impacts of the NESHAP. This possibility 

arises due to the time allowed for implementation of the NESHAP requirements (through 2006) 

and the timing of the NPDES permit renewal schedule (every five years). 

5.3.1 Air Regulations for Brick and Structural Clay Products Manufacturing 

On May 16, 2003, EPA promulgated the NESHAP for brick and structural clay products 

manufacturing, as well as the NESHAP for clay ceramics manufacturing (68 FR 26689). The 

NESHAP for brick and structural clay products manufacturing requires affected manufacturers to 

control the following substances, beginning in 2006: hydrogen fluoride, hydrogen chloride, 

sulfur dioxide, and some metal emissions, including antimony, arsenic, beryllium, cadmium, 

chromium, cobalt, mercury, manganese, nickel, lead, and selenium (68 FR 26692). The 

 

15 SIC codes associated with the Brick and Structural Clay Products Manufacturing industry include: SIC 1455, 

Kaolin & Ball Clay (NAICS 212324); SIC 1459, Clay, Ceramic & Refractory Minerals (NAICS 212325); 3251, 

Brick and Structural Clay Tile (NAICS 327121); SIC 3255, Clay Refractories (NAICS 327120); SIC 3259, 

Structural Clay Products (NAICS 327123); SIC 3271, Concrete Block and Brick (NAICS 327331); and SIC 5032, 

Brick, Stone, and Related Materials (NAICS 423320).
Section 5—Continued Review of Select Industrial Categories

5-41 

NESHAP states that entities potentially affected are those industrial facilities that manufacture 

brick and structural clay products, specifically those classified under the following SIC codes: 

• 3251 (NAICS 327121): Brick and structural clay tile manufacturing facilities; 

• 3253 (NAICS 327122): Extruded tile manufacturing facilities; and 

• 3259 (NAICS 327123): Other structural clay products manufacturing facilities.

The NESHAP for brick and structural clay products manufacturing mentions wet air 

pollution control devices, such as wet scrubbers, as one of three methods to comply with the 

standard. The other two potential methods are dry lime injection fabric filters (DIFF) and dry 

lime scrubbers/fabric filters (DLS/FF) (68 FR 26694). Wet scrubbers have the potential to 

generate new wastewater discharges not regulated by ELGs.

The Clay Ceramics Manufacturing NESHAP states that potentially affected facilities are 

manufacturers of ceramic wall and floor tile or vitreous plumbing fixtures, specifically those 

classified under the following SIC codes: 

• 3253 (NAICS 327122): Ceramic wall and floor tile manufacturing facilities; and16

• 3261 (NAICS 327111): Vitreous plumbing fixtures (sanitaryware) manufacturing 

facilities.

However, EPA did not review the Clay Ceramics Manufacturing NESHAP as part of its 

initial review of air quality regulations in 2012 because the preamble states that no water or solid 

waste impacts are projected for existing or new sources (68 FR 26717). 

Brick and structural clay products manufacturing facilities were required to comply with 

the 2003 NESHAP by May 2006. However, in 2007, in response to a complaint filed by the 

Sierra Club, the U.S. District Court for the District of Columbia vacated the rule. The lawsuit 

claimed EPA failed to meet its obligations under the Clean Air Act by not including all 

technologies in developing the standards, including technologies that were not necessarily 

achievable by all sources (Sierra Club vs. EPA, 2007). Currently, EPA is planning to propose a 

revised rule in August 2014 and issue final regulations by June 2015 (OMB, 2014). 

5.3.2 2014 Annual Review of Brick and Structural Clay Products Manufacturing 

EPA’s review of the brick and structural clay products manufacturing industry, as part of 

the 2012 Annual Review, suggested that the majority of brick and structural clay manufacturing 

facilities only have stormwater discharges, not process discharges, associated with 

manufacturing or wet air pollution control. However, because of the timing allowed for 

implementation of the NESHAP requirements (through 2006) and the NPDES permit renewal 

schedule (every five years), EPA’s evaluation of 2009 DMR data may not have fully captured 

 

16 Facilities in SIC Code 3253 (ceramic wall and floor tile manufacturing facilities and extruded tile manufacturing 

facilities) are subject to both the Clay Ceramics Manufacturing NESHAP and the Brick and Structural Clay Products 

Manufacturing NESHAP (68 FR 26690). 
Section 5—Continued Review of Select Industrial Categories

5-42 

the potential impact of the NESHAP. Therefore, EPA continued its investigation of brick and 

structural clay manufacturing facilities during the 2014 Annual Review. 

As part of this 2014 Annual Review, EPA’s Office of Water contacted EPA’s Office of 

Air and Radiation (OAR) and the Brick Industry Association (BIA) to learn more about the 

NESHAP and the potential impacts on the industry, specifically regarding the installation of wet 

air pollution controls. Both contacts stated that wet scrubbers are not a common air pollution 

control method within the industry and that only a small number of brick and structural clay 

manufacturing facilities have them installed (Miller, S., 2014; Telander, J., 2014). OAR also 

provided information on the number of brick manufacturing facilities and clay ceramics facilities 

that have installed wet scrubbers, as discussed in the sections below. 

5.3.2.1 Review of Brick Manufacturing Facilities

As of 2014, only two of the 345 brick manufacturing facilities in the U.S. (as identified 

by SIC Codes 3251, 3253, and 3259) have wet scrubbers (Telander, J., 2014; U.S. Census, 

2011). Table 5-15 presents these facilities. However, both facilities are synthetic minor sources 

and would not be subject to the brick and structural clay products manufacturing NESHAP 

(Telander, J., 2014). Synthetic minor sources are those facilities using some emission control 

device (or devices) required by a Federally Enforceable State Operating Permit (FESOP) and 

which thereby emit fewer than 10 tons per year of any hazardous air pollutants (HAP) and fewer 

than 25 tons per year of any combination of HAP. In the absence of such controls, these sources 

would be major17 (68 FR 26697). 

The first facility, Interstate Brick, in West Jordan, UT, has two wet scrubbers, the first 

installed in 1996, and the second in 2000 (Telander, J., 2014). Interstate Brick manufactures a 

full line of standard brick products used in residential and commercial construction (Interstate 

Brick, 2014). The facility is included in the DMR Loading Tool, but it has no reported 

wastewater discharges between 2007 and 2011. 

The second facility, Glen-Gery Corporation’s Hanley Plant in Summerville, PA, has one 

wet scrubber, installed in 2003 (Telander, J., 2014). Glen-Gery produces high quality 

architectural brick at the Hanley Plant, which the company has owned since 1986 (Glen-Gery 

Brick, 2014). The facility is not included in the DMR Loading Tool and has no reported 

wastewater discharges between 2007 and 2011. 

Table 5-15. Brick Manufacturing Facilities in the U.S.

Company Name

Facility 

Name

Facility 

Location

Type of 

Source

DMR 

Discharges Facility SIC Codes

Pacific Coast 

Building Products

Interstate 

Brick

West Jordan, 

UT

Kiln None 3271 – Concrete Block and Brick

3251 – Brick and Structural Clay 

Tile 

 

17 A major source is any stationary source or group of stationary sources that emits or has the potential to emit 10 

tons per year or more of any hazardous air pollutant, or 25 tons per year or more of any combination of hazardous 

air pollutants.
Section 5—Continued Review of Select Industrial Categories

5-43 

Table 5-15. Brick Manufacturing Facilities in the U.S.

Company Name

Facility 

Name

Facility 

Location

Type of 

Source

DMR 

Discharges Facility SIC Codes

Glen-Gery 

Corporation

Hanley Plant Summerville, 

PA

Kiln None 3251 – Brick and Structural Clay 

Tile

Source: (EPA Envirofacts; Telander, J., 2014).

5.3.2.2 Review of Clay Ceramics Facilities

EPA did not review the Clay Ceramics Manufacturing NESHAP as part of the initial 

review of air quality regulations in 2012 because the preamble of the rule stated that no water or 

solid waste impacts were projected for existing or new sources (68 FR 26717). However, OAR 

indicated and provided information regarding several clay ceramics facilities in the U.S. that 

have installed wet scrubbers. Table 5-16 presents these facilities. 

As of 2014, two out of 24 facilities in the clay ceramics industry, SIC code 3261, have 

wet scrubbers, both of which are at major sources. Kohler, Co. owns both facilities and each 

facility has one wet scrubber (Telander, J., 2014). Neither facility has reported DMR discharge 

data for years 2007 to 2011 (DMR Loading Tool). 

Three out of 127 facilities in the ceramic tile category, SIC code 3253, have wet 

scrubbers. Dal Italia and the Dal-Tile Dallas Plant each have two wet scrubbers to control air 

emissions from kilns. Florim USA has three wet scrubbers and the Dal-Tile Dallas Plant has two 

wet scrubbers to control air emissions from glaze lines (Telander, J., 2014). None of the facilities 

has reported DMR discharge data for years 2007 to 2011 (DMR Loading Tool). In addition, all 

three of the facilities are synthetic area sources and are therefore not subject to the clay ceramics 

manufacturing NESHAP (Telander, J., 2014). 
Section 5—Continued Review of Select Industrial Categories

5-44 

Table 5-16. Clay Ceramics Facilities in the U.S.

Category

Company 

Name

Facility 

Name

Facility 

Location

Type of 

Source

DMR 

Discharges Facility SIC Codes

Clay 

Ceramics

Kohler Co. Spartanburg 

Plant

Spartanburg, 

SC

Kiln None 3088 – Plastics Plumbing Fixtures

3261 – Vitreous China Plumbing Fixtures and China and 

Earthenware Fittings and Bathroom Accessories

Clay 

Ceramics

Kohler Co. Wisconsin 

Plant

Kohler, WI Glaze spray 

booth

None 3261 – Vitreous China Plumbing Fixtures and China and 

Earthenware Fittings and Bathroom Accessoriesa

3431 – Enameled Iron and Metal Sanitary Ware

3432 – Plumbing Fixtures and Trim 

3519 – Internal Combustion Engines, not elsewhere classified 

3541 – Machine Tools, Metal Cutting Types 

3471 – Electroplating, Plating, Polishing, Anodizing, and 

Coloring

Ceramic Tile Dal-Tile 

Corporation

Dal Italia Muskogee, OK Kiln None 3253 – Ceramic Wall and Floor Tile

Ceramic Tile Mohawk 

Industries

Dal-Tile 

Dallas Plant

Dallas, TX Kiln & Glaze 

spray booth

None 3253 – Ceramic Wall and Floor Tile 

3251 – Brick and Structural Clay Tile

Ceramic Tile Florim 

Ceramiche 

S.p.A.

Florim USA Clarksville, TN Glaze Spray 

Booth

None 3253 – Ceramic Wall and Floor Tile

Source: (EPA Envirofacts; Telander, J., 2014). a Kohler Co. is major plant with many operations. This analysis focused on operations related to SIC 3261 – Vitreous China Plumbing Fixtures and China and 

Earthenware Fittings and Bathroom Accessories, which corresponds to the SIC code covered by the Clay Ceramics Manufacturing NESHAP. 
Section 5—Continued Review of Select Industrial Categories

5-45

5.3.3 Summary of Findings from EPA’s Review of Brick and Structural Clay Products 

Manufacturing

EPA’s investigation of the brick and structural clay products manufacturing industry, 

outlined above, determined that only seven out of approximately 496 facilities producing brick, 

structural clay, and clay ceramics currently have wet scrubbers installed. Some of these were 

installed prior to the 2003 NESHAPs. EPA also found that the seven facilities with wet scrubbers 

did not report any DMR discharges for reporting years 2007 through 2011. These findings 

suggest that wet scrubbers are not a common air pollution control method within the industry and 

not expected to increase; therefore, they are not a potential new source of industrial wastewater 

discharge warranting regulation. 

5.3.4 References for the Continued Review of Brick and Structural Clay Manufacturing

1. Glen-Gery Brick. 2014. History of Glen-Gery Brick. Available online at:

http://www.glengery.com/about-us/history. Accessed: June 20, 2014. EPA-HQ-OW2014-0170. DCN 07988.

2. Interstate Brick. 2014. Interstate Brick History. Available online at:

http://www.interstatebrick.com/history.html. Accessed: June 20, 2014. EPA-HQ-OW2014-0170. DCN 07989.

3. Miller, S. 2014. Telephone Communication Between Susan Miller, Brick Industry

Assocoation, and Amie Aguiar, Eastern Research Group, Inc. Re: Brick Manufacturing

Process. (April 17). EPA-HQ-OW-2014-0170. DCN 07990.

4. OMB. 2014. Office of Management and Budget. RIN data for National Emission

Standards for Hazardous Air Pollutants (NESHAP): Brick and Structural Clay Products

Manufacturing and Clay Ceramics Manufacturing. Available online at:

http://www.reginfo.gov/public/do/eAgendaViewRule?pubId=201404&RIN=2060-AP69.

EPA-HQ-OW-2014-0170. DCN 07991.

5. Sierra Club vs. EPA, 2007. U.S. Court of Appeals for the District of Columbia Circuit,

No. 03-1202. March 13, 2007. Available online at:

http://www.cadc.uscourts.gov/internet/opinions.nsf/3DE6EA395F4B40A6852574400045

37C7/$file/03-1202a.pdf. EPA-HQ-OW-2014-0170. DCN 07992.

6. Telander, J. 2014. Email Communication Between Jeff Telander, U.S. EPA Office of Air

and Radiation, and William Swietlik, U.S. EPA Office of Water. Re: Brick and Clay

Follow-up. (May 21). EPA-HQ-OW-2014-0170. DCN 07993.

7. U.S. Census. 2011. U.S. Economic Census: 2011 County Business Patterns. Available

online at: http://factfinder2.census.gov/faces/nav/jsf/pages/searchresults.xhtml?refresh=t.

Accessed: March 26, 2014. EPA-HQ-OW-2014-0170. DCN 07994.

8. U.S. EPA. 2005. Fact Sheet for National Emission Standards for Hazardous Air

Pollutants for Brick and Structural Clay Products Manufacturing: Reconsideration.

Washington, D.C. (April 22). EPA-HQ-OW-2014-0170. DCN 07995.
Section 5—Continued Review of Select Industrial Categories

5-46 

9. U.S. EPA. 2014. The 2012 Annual Effluent Guidelines Review Report. Washington, D.C. 

(September). EPA-821-R-14-004. EPA-HQ-OW-2010-0824-0320. 

10. Warren, L. 2012. Telephone Communication Between Lee Warren, Alabama Department 

of Environmental Management, and Kimberly Landick, Eastern Research Group, Inc. Re: 

Brick Manufacturing Process. (March 21). EPA-HQ-OW-2010-0824. DCN 07737. 
Section 6—New Data Sources and Additional Supporting Analyses

6-1 

6. NEW DATA SOURCES AND ADDITIONAL SUPPORTING ANALYSES

For the 2014 Annual Review, EPA initiated a review of engineered nanomaterials, which 

are an emerging pollutant group of concern, and continued its review of industrial wastewater 

treatment technology performance data and population of the Industrial Wastewater Treatment 

Technology (IWTT) Database. EPA’s goals in conducting these reviews were to identify new 

wastewater discharges or pollutants not previously regulated and to identify wastewater 

discharges that can be eliminated or treated more effectively.

EPA documented the usability and quality of the data supporting these reviews, analyzed 

how the data could be used to improve the characterization of industrial wastewater discharges 

(detection or monitoring of pollutants, wastewater treatment available for new 

industries/concentrations), and prioritized the findings for further review. See Appendix B of this 

report for more information on data usability and quality of the data supporting these reviews. 

Sections 6.1 and 6.2 of this report provide details of each of these reviews.

6.1 Review of Engineered Nanomaterials in Industrial Wastewater

As part of the 2014 Annual Review, EPA began evaluating engineered nanomaterials 

(ENMs) as a potential emerging industrial wastewater pollutant category. Nanotechnology is a 

rapidly advancing field of research and commerce and offers potential benefits for health, 

consumer products, and electronics applications. According to the Woodrow Wilson 

International Center for Scholars’ Project on Emerging Nanotechnology’s Nanotechnology 

Consumer Product Inventory, ENMs are currently used in over 800 consumer products in the 

U.S. (Project on Emerging Nanotechnologies, 2014). 

In its Final 2010 Effluent Guidelines Program Plan, EPA solicited data and information 

for future annual reviews on the manufacture, use, and environmental release of silver materials, 

including nanosilver, due to their anti-microbial activity and potential to create a source of silver 

in associated industrial wastewater discharges (U.S. EPA, 2011a). Several commenters indicated 

that EPA should investigate the impact of nanosilver; a few in particular indicated that EPA 

should investigate all nanomaterials (U.S. EPA, 2013c). In addition, recent research presented at 

the Society of Environmental Toxicology and Chemistry (SETAC) North America 33rd Annual 

Meeting in November 2012 indicates that ENMs may impact human health and the environment. 

Although researchers have conducted little direct sampling and analysis of industrial wastewater 

discharges, they have identified industrial discharges as a possible route for ENMs to enter the 

environment (Gottschalk and Nowack, 2011; Hendren et al., 2011; Musee, 2011). 

As part of the 2014 Annual Review, EPA responded to the recent interest, research, and 

concerns raised in comments by reviewing current literature about the fate, transport, and effects 

of nanomaterials on the environment and human health and about the presence and discharge of 

nanomaterials in industrial wastewater. This review summarizes EPA’s current knowledge of, 

and outstanding data gaps related to, characterizing and quantifying the presence and impact of 

ENMs in industrial wastewater discharges.
Section 6—New Data Sources and Additional Supporting Analyses

6-2 

6.1.1 Literature Review and Research Methodology

EPA assessed available information to support the evaluation of potential industrial 

wastewater discharges and associated risks of discharged ENMs. EPA’s review focused on: 

• Production methods and potential aqueous waste streams from manufacturing and 

processing ENMs; 

• Fate, transport, and potential effects of nanomaterials on human health and the 

environment; 

• Analytical techniques available to detect nanomaterials in industrial wastewater;

• Presence of nanomaterials in industrial wastewater; and

• Treatment technologies to remove nanomaterials from wastewater.

SETAC’s 2012 conference proceedings included over 125 presentations and posters 

about nanomaterial-related research, which primarily focused on fate and transport, toxicity, and 

analytical techniques (SETAC, 2012). EPA reviewed this nanomaterial-related research and 

catalogued relevant abstracts as a starting point for further research.

Next, EPA identified (partly through the SETAC abstracts) principal government and 

university researchers and organizations that focus on studying the environmental impacts of 

ENMs. Several EPA offices are currently assessing the potential effects of ENMs on human 

health and the environment through research into chemical safety, characterization techniques, 

life cycle assessment, and risk assessment of these nanomaterials in air, water, and soil (U.S. 

EPA, 2013a). EPA identified additional stakeholders based on nanomaterials-related research 

conducted by these EPA offices, including the Office of Pollution Prevention and Toxics (OPPT) 

and the Office of Research and Development’s (ORD’s) National Exposure Research Laboratory 

(NERL).

EPA communicated with the following researchers and government stakeholders between 

March and June 2013: 

• Mark Wiesner, James L. Meriam Professor, Department of Civil and 

Environmental Engineering, Duke University; Director of the Center for the 

Environmental Implications of Nanotechnology (CEINT).

• Michael Hochella Jr., University Distinguished Professor, Department of 

Geosciences, Virginia Tech; member of CEINT.

• Paul Westerhoff, Professor, School of Sustainable Engineering and the Built 

Environment, Associate Dean for Research and Graduate Affairs, Ira A. Fulton 

Schools of Engineering, Arizona State University. 

• David Meyer, Chemical Engineer, EPA ORD National Risk Management 

Research Laboratory (NRMRL), Sustainable Technologies Division. 

• Thabet Tolaymat, Environmental Engineer, EPA ORD NRMRL.
Section 6—New Data Sources and Additional Supporting Analyses

6-3 

• Katrina Varner, Research Chemist, EPA ORD NERL–Las Vegas/Environmental 

Sciences Division/Environmental Chemistry Branch.

• Steve Diamond, EPA National Health and Environmental Effects Research 

Laboratory, Mid-Continent Ecology Division–Duluth. 

• Jeff Morris, Deputy Director for Programs, EPA OPPT.

• Phil Sayre, EPA Deputy National Program Director for the Chemical Safety for 

Sustainability Research Program.

• Jim Alwood, Program Manager and Toxic Substances Control Act 

Nanotechnology Coordinator, EPA OPPT, Chemical Control Division. 

• Barbara Karn, Program Director, National Science Foundation; Vice President, 

Sustainable Nanotechnology Organization. 

• Suzanne Davis, Hazardous Substances Engineer, California Department of Toxic 

Substances Control. 

EPA reviewed literature and research identified using the following search engines:

• American Chemical Society Publications (http://pubs.acs.org), a comprehensive 

collection of the most-cited peer-reviewed journals in chemistry and related 

sciences; 

• ScienceDirect (http://www.sciencedirect.com/), a full-text scientific database 

offering over 2,500 peer-reviewed journals; and

• Google Scholar (http://scholar.google.com), which provides a broad search of 

scholarly literature across disciplines, publishers, and online databases.

In addition, EPA searched for articles written by SETAC 2012 conference participants 

and scanned titles and abstracts to identify relevant articles, using various keyword combinations 

to further focus the literature search. From the articles identified, EPA performed additional 

searches to find other relevant articles from co-authors and references.

EPA created a comprehensive EndNote® reference library to store and organize 

references (ERG, 2014). Because nanotechnology is an emerging field of study, EPA strived to 

collect the most recent research, gathering material published from 2006 to December 2013. All 

articles are government publications, peer-reviewed, or conference proceedings and meet the 

data quality objectives outlined in the Environmental Engineering Support for Clean Water 

Regulations Programmatic Quality Assurance Project Plan (ERG, 2013). 

EPA’s literature review and research methodology are further documented in the 

memorandum Engineered Nanomaterials in Industrial Wastewater: Literature Review and 

Implications for 304m (ERG, 2015). 
Section 6—New Data Sources and Additional Supporting Analyses

6-4 

6.1.2 Overview of Nanomaterials

Nanomaterials are generally defined as engineered or naturally occurring materials 

composed of primary particles, with sizes on the order of 1 to 100 nanometers (nm) in at least 

one dimension, that show physical, chemical, and biological properties not found in bulk samples 

of the same material (U.S. EPA, 2011b). These primary particles, termed nanoparticles, may 

exhibit novel, size-dependent characteristics such as increased strength, chemical reactivity, and 

conductivity due to their high surface area-to-volume ratio. This proportionally large surface area 

makes nanoparticles more reactive and responsive to their surroundings and influences mobility, 

aggregation, and stability in soil and water (Gavankar et al., 2012). 

Naturally occurring nanomaterials are ubiquitous in the environment, but have only 

recently been discovered due to advances in microscopy (Hochella et al., 2008). Their

background levels and mass distribution are largely unknown. In some cases, nanomaterials may 

also be incidental, meaning that they are unintentionally produced through industrial activities, 

notably through emissions from fossil fuel combustion and manufacturing (Wiesner et al., 2009). 

Engineered nanomaterials are produced to serve a particular purpose and represent a 

new or additional input to the environment. The most common ENMs are classified into two 

categories: carbon-based and inorganic or metal-containing ENMs. Table 6-1 lists common types 

of ENMs.

Table 6-1. Common Types of Engineered Nanomaterials

Category Engineered Nanomaterial

Carbon-based ENMs

Carbon nanotubes

Fullerenes

Graphene

Inorganic `or metal-containing ENMs

Silver

Titanium dioxide

Quantum Dots

Cerium Oxide

Zinc Oxide

Iron

Copper

Silicon

Gold

Bi- and tri-metallic alloys

Source: SETAC (2012) and U.S. EPA (2013a). 

Some ENMs, such as cadmium selenide quantum dots and some complex carbon-based 

nanomaterials, are completely novel and do not occur in nature. Any of these materials detected 

in the environment can be assumed to be anthropogenic (ERG, 2008; Hochella, 2013). However, 

many types of nanomaterials that can be engineered also occur naturally in the environment, 

particularly silver and metal oxides. Silver ENMs are used extensively as an antimicrobial agent 

in consumer products, but silver particles on the nanoscale are also found in nature. In addition, 

titanium dioxide (TiO2) nanoparticles that are identical to engineered nanoparticles have been 

found in rivers that do not receive wastewater discharges and are remote from industrial 

activities (Hochella, 2013). 
Section 6—New Data Sources and Additional Supporting Analyses

6-5 

Based on the recommendation of several leading researchers, EPA’s review of current 

research focused on three classes of ENMs: silver, TiO2, and carbon-based nanomaterials 

(Hochella, 2013; Wiesner, 2013). Researchers estimate that these three classes are produced in 

the largest volumes and are commonly used in commercial and consumer products. In addition, 

research has more fully classified their impact on human health and the environment relative to 

the impacts of other types of ENMs (for which there is little information). 

6.1.3 Engineered Nanomaterial Production Methods, Volumes, and Potential Sources of 

Industrial Discharge

To understand the potential sources and magnitude of ENMs in industrial wastewater 

discharges, EPA gathered available information on both ENM manufacturing and ENM

processing into nano-enabled products (products containing nanomaterials). Manufacturing is the 

synthesis of ENMs; processing (or formulating) includes any industrial transformation or 

processing of ENMs into a form that could be used to make nano-enabled products, as well as 

manufacturing of nano-enabled products. EPA also collected information about the generation 

and handling of aqueous waste streams produced during manufacturing and processing. 

ENM manufacturing occurs by both wet (chemical) and dry (gas) phase processes. Wetphase chemical synthesis, including chemical reduction, sulfate, sol-gel, and hydrothermal 

methods (Fabrega et al., 2011; Liu et al., 2013; Mulfinger et al., 2007; Robichaud et al., 2009), 

may generate aqueous waste streams (Eckelman et al., 2012; Musee, 2011). Wet-phase processes 

are more common in the manufacture of silver and nano-TiO2, though research suggests that 

about 60 percent of the world’s manufactured nano-TiO2 is synthesized through a gas-phase 

chloride process (Liu et al., 2013). Carbon nanotubes (CNTs) are most commonly manufactured 

using dry-phase processes, including chemical vapor deposition, arc ablation, or high-pressure 

carbon monoxide (Eckelman et al., 2012; Healy et al., 2008). Although dry-phase processes do 

not generate an aqueous waste stream, common procedures following both wet- and dry-phase 

synthesis, such as purification and washing, may also generate aqueous waste. 

ENMs are formulated into industrial and domestic products, chemicals, and other 

materials to create nano-enabled products for many industrial sectors. Nano-TiO2 is used as a 

catalyst and incorporated into paints, coatings, plastics, paper, and cosmetics. Nano-TiO2 is also 

used as a semiconductor and in water treatment and remediation applications. Silver ENMs are 

widely used in consumer products, textiles, and biomedical applications for their antimicrobial 

properties (U.S. EPA, 2013a). CNTs are used in the electronics, polymer, and biomedical 

industries, with ongoing research into their applications for the energy and consumer goods 

sectors (Mueller and Nowack, 2008). 

Researchers indicate that processing ENMs into nano-enabled products may be more 

likely to produce an aqueous waste stream than manufacturing ENMs because many of the nanoenabled products may be formulated with the ENMs in solution (Wiesner, 2013). The extent of 

processing, however, is likely proprietary and could be highly variable, depending on the 

intended use. As a result, EPA could not identify adequate information to characterize and 

quantify the waste streams generated from ENM processing.
Section 6—New Data Sources and Additional Supporting Analyses

6-6 

Although available literature suggests that aqueous waste streams are likely generated 

through manufacturing and processing of ENMs, it is unclear how these waste streams are 

managed and ultimately disposed, particularly from industrial manufacturing and processing. In 

laboratory synthesis of ENMs, unused reagents and chemical wastes are strictly managed, and 

are likely to be handled as hazardous waste and not released as wastewater (Eckelman et al., 

2012). In addition, researchers suggest that laboratory-generated waste streams are probably 

recovered or reused due to the high cost of producing ENMs (Wiesner, 2013). 

To understand the magnitude of potential industrial wastewater discharges, EPA searched 

for information on the number of facilities manufacturing and processing ENMs and the 

production quantities and waste volumes generated. Commercial ENM manufacturing methods, 

processing methods, and production volumes are often proprietary in nature. The EPA Nanoscale 

Materials Stewardship Program solicited voluntary reports from U.S. companies producing 

ENMs in 2008 (U.S. EPA, 2013b). The program estimated that about 600 companies 

manufactured, processed, or used nanotechnology in 2005; although the program expected 

reports from 240 entities, it received only 31. Of the companies that responded, only two 

publicly reported any production data. These two companies reported manufacturing capacity, 

but not the actual quantities of nanomaterials manufactured (Hendren et al., 2011). In a separate 

effort, Duke University researchers, using data from patents, company websites, and requests, 

identified 30 companies producing either silver, nano-TiO2, or CNTs (provided in Appendix D) 

(Hendren et al., 2011). 

EPA’s OPPT recently promulgated Significant New Use Rules (SNURs) for CNTs under 

the authority of the Toxic Substances Control Act, which became effective in August and 

October 2013 (U.S. EPA, 2013d, 2013e). These SNURs require entities that intend to 

manufacture, process, or use certain CNTs to notify EPA at least 90 days before engaging in a 

significant new use. Any Significant New Use notices made under these SNURs will give EPA 

the opportunity to evaluate the intended new uses of the CNTs and, if necessary, to limit or 

prohibit activity to mitigate any unreasonable risks to human health and the environment. 

In general, EPA found that manufacturing and processing ENMs, particularly silver 

nanoparticles, is likely to generate aqueous waste streams; however, very little publically 

available information exists to characterize the waste streams or describe how the aqueous 

wastes are managed and disposed. Further, the universe of facilities manufacturing and 

processing ENMs and the associated production volumes are not well understood. 

6.1.4 Fate, Wastewater Treatment, and Toxicity 

ENMs are likely to be transformed and exist in different forms in the environment than 

the original form in which they were created. ENMs undergo complex and dynamic 

transformations in aqueous media, the extent of which are not fully understood (Lowry et al., 

2012b). The different forms in which a nanomaterial may exist will influence its fate, reactivity, 

and toxicity in the environment. 
Section 6—New Data Sources and Additional Supporting Analyses

6-7 

6.1.4.1 Fate and Environmental Transformations 

Particle size and surface area influence the degree of interaction ENMs will have with 

substances and organisms in the environment. A larger surface area (smaller particle) allows for 

greater reaction rates (Healy et al., 2008). Surface coatings that are either engineered onto the 

nanomaterial or attached through transformations can strongly influence the solubility and 

reactivity of the ENM. Nanoparticles may be transformed in water through any of the following 

mechanisms (Lowry et al., 2012b; Wiesner et al., 2011): 

• Nanoparticle aggregation;

• Formation of complexes with other molecules in water, soil, or biological 

systems;

• Sorption processes; 

• Degradation; and

• Dissolution of coatings or the core particle. 

The interactions and transformations that occur are also dependent on the chemistry of 

the environment, which will affect the mobility and bioavailability of the nanomaterial. In 

addition, most nanomaterials in the environment tend to aggregate and do not exist as single, 

dispersed nanoparticles in water (Zhang et al., 2008). The fate and common interactions of silver, 

CNTs, and nano-TiO2 with the aqueous environment are discussed below. 

Silver nanoparticles readily form complexes with sulfur in various aqueous media, 

which can transform the nanoparticle into many different forms. The nanoparticle can be 

oxidized into silver ions or remain a nanoparticle and form complexes with other chemicals in 

the environment, such as sulfur (Dale et al., 2013). Silver nanoparticle sulfidation has been 

demonstrated in many environmental media, notably during activated sludge treatment in 

wastewater treatment plants (WWTPs) (Doolette et al., 2013; Kim et al., 2010), in the laboratory 

(Levard et al., 2011), and in the natural environment (Levard et al., 2012; Lowry et al., 2012a). 

Researchers at CEINT constructed wetland mesocosms to study the long-term behavior of silver 

nanoparticles. A study of polyvinylpyrrolidone-coated silver nanoparticles indicated that a 

majority of the silver nanoparticles were transformed to silver-sulfide compounds and primarily 

partitioned to soils and sediments (70 percent by weight) (Lowry et al., 2012a). Researchers at 

Carnegie Mellon University reported that silver nanoparticles are transformed to similar 

chemical forms as bulk silver in a pilot WWTP (Ma et al., 2013). 

TiO2 nanoparticles are highly reactive with sunlight and can act as catalysts. This 

behavior can vary depending on the form and surface coatings of nano-TiO2, which has certain 

implications for toxicity (U.S. EPA, 2010b). Nano-TiO2 is fairly soluble in water and solubility 

increases when organic material is present. Studies on environmental transformations of nanoTiO2 are limited (Liu et al., 2013). The nanoparticles have a strong tendency to form aggregates 

at neutral pH, but aggregation strongly depends on the chemistry of the medium (Liu et al., 

2013). 

Carbon nanotubes have a high affinity to partition to solid phases. However, CNTs may 

stay suspended in water in aqueous environments with high concentrations of dissolved organic 
Section 6—New Data Sources and Additional Supporting Analyses

6-8 

matter. The environmental transformations CNTs undergo are not well understood, and may vary 

depending on the structure of the CNTs (Petersen et al., 2011). The chemistry of the environment 

can also change the physiochemical properties of CNTs, which can affect their behavior. For 

example, high-salinity environments increase CNT aggregation (Eckelman et al., 2012). 

6.1.4.2 Wastewater Treatment

The transformation, fate and behavior, and treatment of nanomaterials in industrial 

wastewaters have not been studied. However, their presence and fate has been studied in 

municipal wastewater, in part to determine how well current municipal treatment systems 

remove ENMs from wastewater. Common treatment technologies employed in municipal 

WWTPs, such as activated sludge, settling, and filtration, are effective at removing 

nanomaterials from the wastewater, although nanoparticles likely partition to the sewage sludge 

(biosolids generated as a byproduct of wastewater treatment). More than 90 percent of 

nanomaterials may leave wastewater by sorption to biomass and subsequent settling or filtration 

during wastewater treatment; however, removal efficiency strongly depends on the size of the 

nanomaterials (Westerhoff et al., 2011). 

In addition, nanomaterials tend to aggregate in water, so conventional sedimentation 

processes can be effective in removing nanomaterials from wastewater. Conventional 

coagulation and sedimentation can remove 20 to 60 percent of total nanoparticles, as measured 

by mass (Zhang et al., 2008). After conventional treatment, tertiary filtration processes can

further remove nanomaterials from the water. For example, WWTPs using microfiltration 

removed TiO2 nanoparticles more effectively than those using conventional settling methods 

(Westerhoff et al., 2011). 

The applicability of municipal wastewater research to industrial wastewater is unknown. 

Nanomaterial reactions and transformations may vary depending on the aqueous environments, 

and industrial wastewater tends to have higher concentrations and varieties of constituents than 

either municipal wastewater or the ambient environment. In addition, industrial wastewater 

quality varies greatly between point source categories and industrial processes. For these reasons, 

the behavior of nanomaterials in industrial wastewater treatment systems warrants further study.

6.1.4.3 Toxicity and Exposure 

Though toxicity studies have been conducted, research has focused on ENM toxicity in 

controlled laboratory environments using ENMs in the form in which they were created. To date, 

EPA has not identified any studies on toxicity from exposures to ENMs in industrial wastewater.

Research on ENM toxicity, described below, largely has not considered relevant forms and 

concentrations of nanomaterials that may be present in complex media, such as industrial 

wastewater (Gottschalk and Nowack, 2011; Lowry et al., 2012b). In addition, few toxicity 

studies have been conducted within complex media and ecosystems, where exposures will likely 

be at lower concentrations and where a diversity of organisms is present (Colman et al., 2013). 

The complex interactions and interdependencies within an ecosystem, especially at the microbial 

level, will influence the hazardous effects of ENMs. Some researchers recommend that fate and 

toxicity measurements should be made in complex, natural systems in order to accurately assess 

hazards (Lowry et al., 2012b; Wiesner et al., 2009). 
Section 6—New Data Sources and Additional Supporting Analyses

6-9 

ENM toxicity testing has shown adverse effects on aquatic organisms and the 

environment. The primary toxicity mechanism for silver nanomaterials is their dissolution into 

silver ions (Arnaout and Gunsch, 2012; Nowack et al., 2011). Silver ions cause oxidative stress 

in microorganisms and aquatic organisms (Yang et al., 2012), but toxic impacts in humans are 

only observed at very high concentrations (Nowack et al., 2011). However, it is unclear whether 

silver nanoparticles exhibit novel toxicity mechanisms, outside of generating silver ions. 

Therefore, the observed toxicity effects in silver nanoparticles may not differ from those of bulk 

or colloidal silver (Nowack et al., 2011). 

Titanium dioxide nanomaterials may exhibit ecotoxicity impacts because of their 

catalytic surfaces (Hochella, 2013). Nano-TiO2 can be activated by sunlight to produce reactive 

oxygen species, which cause cellular damage. Nano-TiO2 has been shown to suppress the growth 

of freshwater green algae, which is a concern for freshwater habitats (Cardinale et al., 2012). 

Researchers have observed photo-dependent mortality effects in model organisms exposed to 

nano-TiO2 in the part per billion range (Alloy and Roberts, 2012; Heideman et al., 2012). This 

implies that exposure to sunlight in ecosystems with nano-TiO2 may threaten organisms in 

shallow surface waters and soils. However, more research is needed to determine nano-TiO2

impacts on aquatic ecosystems and microorganisms in particular.

A main mechanism for carbon nanotubes toxicity is the production of reactive oxygen 

species, which is strongly affected by nanotube structure, as the ability to generate reactive 

oxygen species may increase as the size of the nanotubes decrease (Chae et al., 2011). Various 

studies have shown that exposure to CNTs can cause growth inhibition, hatching delays, and 

mortality in some aquatic organisms (Petersen et al., 2011). 

Though the majority of toxicity studies to date were conducted using untransformed 

nanoparticles in laboratory environments, toxicity studies conducted in simulated natural 

environments (mesocosms) and natural environments have reported fewer toxic effects. This 

suggests that ENM impacts are affected and potentially dampened by environmental 

transformations, microbial activity, and the physical and chemical properties of the environment 

(Colman et al., 2012; Unrine et al., 2012). For example, researchers at CEINT have shown that 

the short-term impacts of silver nanoparticles on microbes are attenuated by stream water and 

sediment (Colman et al., 2012). However, even low doses of silver nanoparticles may have 

appreciable effects on an environment, such as shifting wetland microorganism populations 

(Colman et al., 2013). 

Currently, human health effects of nanomaterials in any environmental medium are not 

fully understood, but risks are presumed to be rather low. However, there have been recent 

efforts to minimize airborne exposure to nanomaterials in the workplace due to concern for 

inhalation hazards. In 2013, the National Institute for Occupational Safety and Health (NIOSH) 

published guidelines to minimize workplace exposure to nanomaterials (NIOSH, 2013). In 

addition, the Occupational Safety and Health Administration (OSHA) published recommended 

best practices and exposure limits for airborne CNTs and nano-TiO2 (OSHA, 2013). While 

airborne exposure is not a direct concern for the Effluent Guidelines Program, concerns about 

airborne ENM concentrations may increase future use of wet scrubbers for air pollution control, 

with possible generation of an ENM-containing wastewater. 
Section 6—New Data Sources and Additional Supporting Analyses

6-10 

Biosolids generated from wastewater treatment are often used as fertilizers, and land 

application of biosolids is considered a potential major source of environmental exposure to 

ENMs (Lowry et al., 2012b; Westerhoff et al., 2013). Researchers have identified and 

characterized silver and TiO2 nanoparticles in U.S. municipal wastewater sludge samples, which 

raises concerns about this potential exposure pathway (Kim et al., 2010; Kim et al., 2012). 

To estimate the potential exposure and risk to aquatic organisms, researchers have 

developed models that predict the ENM concentrations in the environment. Researchers at the 

Swiss Federal Laboratories for Materials Testing and Research (Empa) calculated predicted 

environmental concentrations (PECs) of several ENMs in WWTP effluent (from a combination 

of industrial and domestic sources) and surface waters in the U.S. based on probabilistic material 

flow analysis of current production volumes (Gottschalk et al., 2009). As shown in Table 6-2, the 

PECs of ENMs in WWTP effluent are orders of magnitude larger than what is predicted for 

surface waters. The researchers then compared the PECs to predicted no effect concentrations 

(PNEC) from ecotoxicological studies and concluded that silver and TiO2 ENMs in WWTP 

effluent may pose a risk to aquatic organisms based on their risk quotients (Table 6-2). A risk 

quotient greater than one indicates a need to further evaluate the risks posed to aquatic 

organisms. 

Table 6-2. Calculated Model Values for Predicted Environmental Concentrations of 

Engineered Nanomaterials in the U.S.

Engineered 

Nanomaterial

Predicted Environmental 

Concentration (PEC) (ng/L)

WWTP Effluent Risk Quotient 

(PEC/PNEC)

WWTP Effluent Surface Water WWTP Effluent Surface Water

Silver 21.0 0.116 30.1 0.17

Nano-TiO2 1,750 2.0 1.8 0.002

CNTs 8.6 0.001 <0.0005 <0.0005

Fullerenes 4.6 0.003 0.023 <0.0005

Source: Gottschalk et al. (2009)

Risk quotients greater than one are indicated in bold.

The Empa model was based on estimated worldwide production volumes, which are 

incomplete and uncertain. Therefore, the significance of the Empa study’s results to the U.S. is 

uncertain. The results do suggest, however, that aquatic ecosystems may be at risk from exposure 

to silver and TiO2 ENMs released into the environment, though the study did not clearly 

distinguish between the impact of potential inputs from manufacturing, processing, and 

dissolution or degradation of ENMs from end-use products. In the absence of discharge data, 

quantifying production and waste volumes for industrial ENM manufacturing and processing is 

critical for developing models that accurately assess the risk associated with environmental 

releases.

6.1.5 Analytical Methods 

Methods for detecting, quantifying, and characterizing nanomaterials in complex 

environmental media, like industrial wastewater, are not fully developed; many of the analytical 

methods developed to date characterize pure nanomaterials in simple media. With additional 

research, some of these methods may be refined and adapted to characterize ENMs in complex 
Section 6—New Data Sources and Additional Supporting Analyses

6-11 

environmental media. Table 6-3 lists some of the current efforts to develop analytical methods 

for ENMs. The organizations listed (among others) are currently researching and developing 

analytical methods to characterize ENMs in both simple and complex media. There is also 

significant effort under way to develop new tools to characterize nanomaterials in the 

environment. Currently, more research characterizing analytical method development for metalcontaining nanomaterials in complex media has been published than for carbon-based 

nanomaterials.

Table 6-3. Research Organizations Developing Analytical Methods for ENMs 

Organization Analytical Method Nanomaterial

EPA Office of Research and Development, 

National Exposure Research Laboratory 

Environmental Sciences Division 

(EPA ORD/NERL/ESD)

Screening and characterization 

methods

Metal-containing 

nanomaterials

Swiss Federal Institute of Aquatic Science 

and Technology (Eawag)

Electron microscopy, mobile laserinduced breakdown detection Not specified

Center for the Environmental Implications of 

Nanotechnology (CEINT)

Testing protocols; hyperspectral 

imagery with enhanced darkfield 

microscopy

Silver, TiO2 and other 

metal-oxides

University of California's Center for 

Environmental Implications of 

Nanotechnology (UC-CEIN)

Testing protocols; microscopic and 

spectroscopic methods

Metal oxides, CNTs, 

and others not 

specified

Arizona State University (ASU) Detection and characterization of 

ENMs during water treatment and 

monitoring in complex media

Silver, TiO2, CNTs

Trent University (Ontario, Canada) Monitoring in complex media Silver

Binghamton University, State University of 

New York

Membrane sensor to detect and 

quantify ENMs

Silver, TiO2, and 

quantum dots

Many U.S. and international organizations are working to develop guidance and 

standards for ENM characterization. These organizations include, but are not limited to, 

standard-setting groups such as the International Standardization Organization, ASTM 

International, and the American National Standards Institute; U.S. federal research led by the 

National Institute of Standards and Technology (NIST) is also relevant (NNI, 2013b). The 

Organization for Economic Co-operation and Development has published guidance for safety 

testing and characterization of toxicological properties of ENMs. It is recognized as a living 

document, subject to refinement as research into the development of nanomaterial test methods 

progresses (OECD, 2012). 

Because method development is in its infancy, EPA has not approved standardized 

methods for sampling, detecting, monitoring, quantifying, or characterizing nanomaterials in 

aqueous media. This is a critical area of research because the ability to detect and characterize 

nanomaterials is essential to understanding the implications of their release into the environment 

(U.S. EPA, 2010a). The National Nanotechnology Initiative (NNI) identified the development of 

devices to detect and identify ENMs across their life cycles as a priority; through its initiatives, 

NNI aims to accelerate research. The NNI strategic plan and research priorities are further 

described in Section 6.1.6. Standard method development will also support research into the 

environmental implications of nanomaterials and especially aid in fate and transport research 
Section 6—New Data Sources and Additional Supporting Analyses

6-12 

needed for more accurate exposure and risk assessments. EPA-approved methods are also 

needed before EPA can consider regulating discharges of ENMs in industrial wastewater. 

Once standardized methods are developed to detect, characterize, and quantify ENMs 

discharges to, and concentrations in, the environment, strategies will be needed to distinguish 

between engineered and naturally occurring nanomaterials to fully inform monitoring. 

Engineered and naturally occurring nanoparticles are often indistinguishable under a microscope 

(Hochella, 2013; Wiesner et al., 2011). For example, TiO2 nanoparticles that are identical to 

engineered nanoparticles have been found in rivers that do not receive wastewater discharges and 

are remote from industrial activities (Hochella, 2013). In addition, background levels of naturally 

occurring nanomaterials, as well as nanomaterials incidentally generated during nanomaterial 

processing as a result of chemical transformations, may need to be considered as part of any 

future potential regulatory structure for industrial discharges of ENMs. 

6.1.6 Federal Research and the National Nanotechnology Initiative 

The NNI is a collaborative, interagency U.S. government research and development 

initiative. The NNI provides a framework for individual and cooperative nanotechnology-related 

activities for 20 federal department and agency units, including EPA, with a range of research 

and regulatory roles and responsibilities. The NNI expedites the discovery, development, and 

deployment of nanoscale science and technology to serve the public good; this is accomplished

through a program of coordinated research and development aligned with the missions of the 

participating agencies (NNI, 2013a). NNI agencies and academic research centers coordinate 

research that may facilitate EPA’s understanding of the potential for wastewater discharges from 

ENM manufacture and processing and potential impacts on the environment. 

The 2014 NNI Strategic Plan describes the high-level goals, priorities, and specific 

objectives, for at least the next three years, related to nanotechnology research but does not 

provide performance measures or timeframes for meeting the objectives (NSET, 2014). The NNI 

Strategic Plan describes several areas of research focused on the environmental, health, and 

safety implications of nanotechnology (NSET, 2014). A subset of these research areas, listed 

below, may inform EPA’s understanding of the presence and impact of nanomaterials in 

industrial wastewater discharge:

• Nanomaterial measurement infrastructure; 

• Predictive modeling and informatics; 

• Human exposure and health; 

• Environmental health; and

• Risk assessment and risk management. 

The NNI Strategic Plan also establishes Nanotechnology Signature Initiatives to spotlight 

topical areas that exhibit particular promise, existing effort, and significant opportunity, and to

accelerate their development (NSET, 2014). One initiative in particular applies to the needs of 

the Effluent Guidelines program: Nanotechnology for Sensors and Sensors for Nanotechnology. 

This initiative aims, in part, to support research and development methods and devices to detect 
Section 6—New Data Sources and Additional Supporting Analyses

6-13 

and identify ENMs across their life cycles; this will allow researchers to assess the potential 

human health and environment impacts of ENMs.

NNI member agencies also fund much of the ongoing research discussed in this section

(e.g., research by the National Science Foundation, NIST, NIOSH, OSHA, and others). In 

particular, EPA supports research on environmental exposure, impacts, risk assessment, and 

analytical method development through the National Center for Environmental Research and 

extramural grant, fellowship, and research contract programs (NNI, 2013c). 

6.1.7 Summary of Findings 

Nanotechnology is a rapidly progressing field, expected to continue to grow as the 

number of products and technological applications increases. Some manufacturing and 

processing methods likely generate wastewater, potentially for each of the ENMs of interest 

(silver, nano-TiO2, and CNTs), but the quantity generated and waste management practices are 

not documented. ENM manufacturing and processing span multiple industrial categories, but 

little progress has been made to date to quantify production volumes. 

While some exposure hazards have been demonstrated, the environmental and human 

health risks associated with these materials are largely unknown. Fate and toxicity assessments 

for ENMs, in the forms and relevant concentrations to which organisms will be exposed, are 

needed to accurately determine risk. Industrial wastewater releases of ENMs to the environment 

have not been studied. 

The growth in ENM manufacturing has been accompanied by some research into ENMs’

presence and fate in wastewater. Methods for detecting and characterizing nanomaterials in 

complex media, including industrial wastewater, are under development. Research has also 

shown that common treatment technologies employed in municipal WWTPs are effective at 

removing nanomaterials from the wastewater, and some nanomaterials (e.g., silver, nano-TiO2) 

have been detected in U.S. WWTP biosolids. 

Despite the body of current research, ENMs present a challenge for environmental 

monitoring, risk assessment, and regulation due to their small size, unique properties, and 

complexity. EPA has not approved any standardized methods for sampling, detection, or 

quantification of nanomaterials in aqueous media. New methods and means of quantification 

need to be developed to understand the environmental implications of ENMs and inform future 

regulatory decisions. 

From its review of current literature and research, EPA has identified the following data 

gaps and research appropriate to better assess the potential presence and impact of ENMs in 

industrial wastewater: 

• Development of standard methods and sampling techniques to detect and 

characterize nanomaterials in industrial wastewater; 

• Development of methods to distinguish between naturally occurring and 

engineered nanomaterials in aqueous media;
Section 6—New Data Sources and Additional Supporting Analyses

6-14 

• Evaluation of ENM toxicity impacts and potential occurrence in industrial 

wastewater, taking into consideration relevant forms and concentrations of ENMs; 

• Identification of the universe of facilities, production volumes, and waste 

generated and disposed of from ENM manufacturing and processing; and 

• Evaluation and characterization of the fate, transformation, and treatment of 

ENMs in industrial wastewaters.

While EPA, academic institutions and research centers, and international organizations 

are currently researching many of these areas, more focused research is needed to understand the 

hazards and implications from the environmental release of nanomaterials via industrial 

wastewater discharges.

6.1.8 References for the Review of Engineered Nanomaterials in Industrial Wastewater 

1. Alloy, M., and A. Roberts. 2012. Photo-enhanced toxicity of nano-titanium dioxide 

(anatase) on freshwater zooplankton. Proceedings from the SETAC 33rd Annual 

Meeting. Long Beach, California. (November 15). EPA-HQ-OW-2014-0170. DCN 

08046. 

2. Arnaout, C. L., and C.K. Gunsch. 2012. Impacts of silver nanoparticle coating on the 

nitrification potential of nitrosomonas europaea. Environmental Science & Technology. 

46(10): 5387-5395. www.dx.doi.org/10.1021/es204540z. EPA-HQ-OW-2014-0170. 

DCN 08047. 

3. Cardinale, B. J., R. Bier, and C. Kwan. 2012. Effects of TiO2 nanoparticles on the growth 

and metabolism of three species of freshwater algae. Journal of Nanoparticle Research. 

14(8): 1-8. www.dx.doi.org/10.1007/s11051-012-0913-6. EPA-HQ-OW-2014-0170. 

DCN 08048. 

4. Chae, S. R., M. Therezien, J.F. Budarz, L. Wessel, S.H. Lin, Y. Xiao, and M.R. Wiesner. 

2011. Comparison of the photosensitivity and bacterial toxicity of spherical and tubular 

fullerenes of variable aggregate size. Journal of Nanoparticle Research. 13: 5121-5127. 

EPA-HQ-OW-2014-0170. DCN 08049. 

5. Colman, B. P., C.L. Arnaout, S. Anciaux, C.K. Gunsch, M.F. Hochella, B. Kim, G.V.

Lowry, B. M. McGill, B.C. Reinsch, C.J. Richardson, J.M. Unrine, J.P. Wright, L. Yin, 

and E.S. Bernhardt. 2013. Low concentrations of silver nanoparticles in biosolids cause 

adverse ecosystem responses under realistic field scenario. PLoS ONE. 8(2): e57189. 

Available online at: 

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0057189. EPA-HQ-OW2014-0170. DCN 08050. 

6. Colman, B. P., S.Y. Wang, M. Auffan, M.R. Wiesner, and E.S., Bernhardt. 2012. 

Antimicrobial effects of commercial silver nanoparticles are attenuated in natural 

streamwater and sediment. Ecotoxicology. 21(7): 1867-1877. 

www.dx.doi.org/10.1007/s10646-012-0920-5. EPA-HQ-OW-2014-0170. DCN 08051. 
Section 6—New Data Sources and Additional Supporting Analyses

6-15 

7. Dale, A. L., G.V. Lowry, and E.A. Casman. 2013. Modeling nanosilver transformations 

in freshwater sediments. Environmental Science & Technology. 47(22): 12920-12928. 

www.dx.doi.org/10.1021/es402341t. EPA-HQ-OW-2014-0170. DCN 08052. 

8. Doolette, C. L., M.J. McLaughlin, J.K. Kirby, D.J. Batstone, H. H. Harris, H. Ge, and G. 

Cornelis. 2013. Transformation of PVP coated silver nanoparticles in a simulated 

wastewater treatment process and the effect on microbial communities. Chemistry 

Central Journal. 7(1): 46. (March 4). EPA-HQ-OW-2014-0170. DCN 08053. 

9. Eckelman, M. J., M.S. Mauter, J.A. Isaacs, and M. Elimelech. 2012. New perspectives on 

nanomaterial aquatic ecotoxicity: Production impacts exceed direct exposure impacts for 

carbon nanotoubes. Environmental Science & Technology. 46(5): 2902-2910. 

www.dx.doi.org/10.1021/es203409a. EPA-HQ-OW-2014-0170. DCN 08054. 

10. ERG. 2008. Eastern Research Group, Inc. Sampling and Analysis of Nanomaterials in the 

Environment: A State-Of-The-Science Review [Final Report]. (August). EPA-HQ-OW2014-0170. DCN 08055. 

11. ERG. 2013. Eastern Research Group, Inc. Environmental Engineering Support for Clean 

Water Regulations Programmatic Quality Assurance Project Plan (PQAPP, Rev. 1, 

Approved October 20, 2013). EPA-HQ-OW-2010-0824. DCN 07754. 

12. ERG. 2014. Eastern Research Group, Inc. Engineered Nanomaterials EndNote Reference 

Library. (August). EPA-HQ-OW-2014-0170. DCN 08056. 

13. ERG. 2015. Eastern Research Group, Inc. Engineered Nanomaterials in Industrial 

Wastewater: Literature Review and Implications for 304m. (January). EPA-HQ-OW2014-0170. DCN 08108. 

14. Fabrega, J., S.N. Luoma, C.R. Tyler, T.S. Galloway, and J.R. Lead. 2011. Silver 

nanoparticles: Behaviour and effects in the aquatic environment. Environment 

International. 37(2): 517-531. www.dx.doi.org/10.1016/j.envint.2010.10.012. EPA-HQOW-2014-0170. DCN 08058. 

15. Gavankar, S., S. Suh, and A. Keller. 2012. Life cycle assessment at nanoscale: Review 

and recommendations. The International Journal of Life Cycle Assessment. 17(3): 295-

303. www.dx.doi.org/10.1007/s11367-011-0368-5. EPA-HQ-OW-2014-0170. DCN 

08059. 

16. Gottschalk, F., and B. Nowack. 2011. The release of engineered nanomaterials to the 

environment. Journal of Environmental Monitoring. 13(5): 1145-1155. EPA-HQ-OW2014-0170. DCN 08060. 

17. Gottschalk, F., T. Sonderer, R.W. Scholz, and B. Nowack. 2009. Modeled environmental 

concentrations of engineered nanomaterials (TiO2, ZnO, Ag, CNT, fullerenes) for 

different regions. Environmental Science & Technology. 43(24): 9216-9222. 

www.dx.doi.org/10.1021/es9015553. EPA-HQ-OW-2014-0170. DCN 08061. 
Section 6—New Data Sources and Additional Supporting Analyses

6-16

18. Healy, M. L., L.J. Dahlben, and J.A. Isaacs. 2008. Environmental assessment of singlewalled carbon nanotube processes. Journal of Industrial Ecology. 12(3): 376-393.

www.dx.doi.org/10.1111/j.1530-9290.2008.00058.x. EPA-HQ-OW-2014-0170. DCN

08062.

19. Heideman, W., O. Bar-Ilan, R. Peterson, J. Pedersen, and H. Robert. 2012. TiO2

nanoparticle exposure and illumination during zebrafish development: Mortality at parts

per billion concentrations. Proceedings from the SETAC 33rd Annual Meeting. Long

Beach, California. Available online at:

http://longbeach.setac.org/sites/default/files/SETAC-abstract-book-2012.pdf

EPA-HQ-OW-2014-0170. DCN 08063.

20. Hendren, C. O., X. Mesnard, J. Droge, and M.R. Wiesner. 2011. Estimating production

data for five engineered nanomaterials as a basis for exposure assessment. Environmental

Science & Technology. 45: 2562-2569. EPA-HQ-OW-2014-0170. DCN 08064.

21. Hochella, M. F. 2013. Telephone Communication between Michael Hochella, Virginia

Tech, and Eva Knoth and Kim Wagoner, Eastern Research Group, Inc. Re: Request for

Information on Nanomaterials Research.(March 15). EPA-HQ-OW-2014-0170. DCN

08065.

22. Hochella, M. F., S.K. Lower, P.A. Maurice, R.L. Penn, N. Sahai, D. Sparks, and B.S.

Twining. 2008. Nanominerals, mineral nanoparticles, and earth systems. Science.

319(5870): 1631-1635. www.dx.doi.org/10.1126/science.1141134. EPA-HQOW-2014-0170. DCN 08066.

23. Kim, B., M. Murayama, B.P. Colman, and M.F. Hochella. 2012. Characterization and

environmental implications of nano- and larger TiO2 particles in sewage sludge, and soils

amended with sewage sludge. Journal of Environmental Monitoring. 14(4): 1128-1136.

www.dx.doi.org/10.1039/C2EM10809G. EPA-HQ-OW-2014-0170. DCN 08067.

24. Kim, B., C.S. Park, M. Murayama, and M.F. Hochella. 2010. Discovery and

characterization of silver sulfide nanoparticles in final sewage sludge products.

Environmental Science & Technology. 44(19). www.dx.doi.org/10.1021/es101565j. EPAHQ-OW-2014-0170. DCN 08068.

25. Levard, C., E.M. Hotze, G.V. Lowry, and G.E. Brown. 2012. Environmental

transformations of silver nanoparticles: Impact on stability and toxicity. Environmental

Science & Technology. www.dx.doi.org/10.1021/es2037405. EPA-HQ-OW-2014-0170.

DCN 08069.

26. Levard, C., B.C. Reinsch, F.M. Michel, C. Oumahi, G.V. Lowry, and G.E. Brown. 2011.

Sulfidation processes of PVP-coated silver nanoparticles in aqueous solution: Impact on

dissolution rate. Environmental Science & Technology. 45(12): 5260-5266.

www.dx.doi.org/10.1021/es2007758. EPA-HQ-OW-2014-0170. DCN 08070.

27. Liu, X., G. Chen, A.A. Keller, and C. Su. 2013. Effects of dominant material properties

on the stability and transport of TiO2 nanoparticles and carbon nanotubes in aquatic
Section 6—New Data Sources and Additional Supporting Analyses

6-17 

environments: from synthesis to fate. Environmental Science: Processes & Impacts. 

15(1): 169-189. EPA-HQ-OW-2014-0170. DCN 08071. 

28. Lowry, G. V., B.P. Espinasse, A.R. Badireddy, C.J. Richardson, B.C. Reinsch, L.D.

Bryant, A.J. Bone, A. Deonarine, S. Chae, M. Therezien, B.P. Colman, H. Hsu-Kim, E.S. 

Bernhardt, C.W., Matson, and M.R. Wiesner. 2012a. Long-term transformation and fate 

of manufactured Ag nanoparticles in a simulated large scale freshwater emergent 

wetland. Environmental Science & Technology. 46(13): 7027-7036. 

www.dx.doi.org/10.1021/es204608d. EPA-HQ-OW-2014-0170. DCN 08072. 

29. Lowry, G. V., K.B. Gregory, S.C. Apte, and J.R. Lead. 2012b. Transformations of 

nanomaterials in the environment. Environmental Science & Technology. 46(13): 6893-

6899. www.dx.doi.org/10.1021/es300839e. EPA-HQ-OW-2014-0170. DCN 08073. 

30. Ma, R., C. Levard, J.D. Judy, J.M. Unrine, M. Durenkamp, B. Martin, B. Jefferson, and

G.V. Lowry. 2013. Fate of zinc oxide and silver nanoparticles in a pilot wastewater 

treatment plant and in processed biosolids. Environmental Science & Technology. 

www.dx.doi.org/10.1021/es403646x. EPA-HQ-OW-2014-0170. DCN 08074. 

31. Mueller, N. C., and B. Nowack. 2008. Exposure modeling of engineered nanoparticles in 

the environment. Environmental Science & Technology. 42(12): 4447-4453. 

www.dx.doi.org/10.1021/es7029637. EPA-HQ-OW-2014-0170. DCN 08075. 

32. Mulfinger, L., S.D. Solomon, M. Bahadory, A.V. Jeyarajasingam, S.A. Rutkowsky, and 

C. Boritz. 2007. Synthesis and study of silver nanoparticles. Journal of Chemical 

Education. 84(2): 322. EPA-HQ-OW-2014-0170. DCN 08076. 

33. Musee, N. 2011. Nanowastes and the environment: Potential new waste management 

paradigm. Environment International. 37(1): 112-128. 

www.dx.doi.org/10.1016/j.envint.2010.08.005. EPA-HQ-OW-2014-0170. DCN 08077. 

34. NIOSH. 2013. National Institute for Occupational Safety and Health. Current Strategies 

for Engineering Controls in Nanomaterial Production and Downstream Handling 

Processes. Cincinnati, OH. (November). DHHS (NIOSH) Publication No. 2014–102. 

EPA-HQ-OW-2014-0170. DCN 08078. 

35. NNI. 2013a. National Nanotechnology Initiative. About the NNI. Available online at:

http://nano.gov/about-nni. EPA-HQ-OW-2014-0170. DCN 08079. 

36. NNI. 2013b. National Nanotechnology Initiative. Standards for nanotechnology. 

Available online at: http://nano.gov/you/standards. EPA-HQ-OW-2014-0170. DCN 

08080. 

37. NNI. 2013c. NSI: Nanotechnology for sensors and sensors for nanotechnology: 

Improving and protecting health, safety, and the environment. Available online at:

http://www.nano.gov/NSISensors. EPA-HQ-OW-2014-0170. DCN 08081. 
Section 6—New Data Sources and Additional Supporting Analyses

6-18

38. Nowack, B., H.F. Krug, and M. Height. 2011. 120 years of nanosilver history:

Implications for policy makers. Environmental Science & Technology. 45(4): 1177-1183.

www.dx.doi.org/10.1021/es103316q. EPA-HQ-OW-2014-0170. DCN 08082.

39. NSET. 2014. National Science and Technology Council, Committee on Technology,

Subcommittee on Nanoscale Science, Engineering, and Technology. National

Nanotechnology Initiative Strategic Plan. Washington, D.C. (February). Available online

at: http://www.nano.gov/sites/default/files/pub_resource/2014_nni_strategic_plan.pdf.

EPA-HQ-OW-2014-0170. DCN 08083.

40. OECD. 2012. Organisation for Economic Co-operation and Development. Guidance on

Sample Preparation and Dosimetry for the Safety Testing of Manufactured

Nanomaterials Series on the Safety of Manufactured Nanomaterials. (December 18).

Available online at:

http://search.oecd.org/officialdocuments/displaydocumentpdf/?cote=env/jm/mono(2012)

40&doclanguage=en. EPA-HQ-OW-2014-0170. DCN 08084.

41. OSHA. 2013. Occupational Saftey and Health Administration. OSHA Fact Sheet:

Working Safely with Nanomaterials. Available online at:

https://www.osha.gov/Publications/OSHA_FS-3634.pdf. EPA-HQ-OW-2014-0170. DCN

08085.

42. Petersen, E. J., L. Zhang, N.T. Mattison, D.M. O’Carroll, A.J. Whelton, N. Uddin, T.

Nguyen, Q. Huang, T.B. Henry, R.D. Holbrook, and K.L. Chen. 2011. Potential release

pathways, environmental fate, and ecological risks of carbon nanotubes. Environmental

Science & Technology. 45(23): 9837-9856. www.dx.doi.org/10.1021/es201579y. EPAHQ-OW-2014-0170. DCN 08086.

43. Project on Emerging Nanotechnologies. 2014. Consumer Products Inventory. Available

online at: http://www.nanotechproject.org/cpi. EPA-HQ-OW-2014-0170. DCN 08087.

44. Robichaud, C. O., A.E. Uyar, M.R. Darby, L.G. Zucker, and M.R., Wiesner. 2009.

Estimates of upper bounds and trends in nano-TiO2 production as a basis for exposure

assessment. Environmental Science & Technology. 43: 4227-4233. EPA-HQ-OW-2014-

0170. DCN 08088.

45. SETAC. 2012. Society of Environmental Toxicology and Chemistry. SETAC North

America 33rd Annual Meeting Abstract Book. Long Beach, California. (November 15).

Available online at: http://longbeach.setac.org/sites/default/files/SETAC-abstract-book2012.pdf. EPA-HQ-OW-2014-0170. DCN 08089.

46. U.S. EPA. 2010a. Characterizing Concentrations and Size Distributions of MetalContaining Nanoparticles in Waste Water. Washington, D.C. EPA/600/R-10/117. EPAHQ-OW-2014-0170. DCN 08090.

47. U.S. EPA. 2010b. Nanomaterial Case Studies: Nanoscale Titanium Dioxide in Water

Treatment and in Topical Sunscreen. Washington, D.C. EPA/600/R-09/057F. EPA-HQOW-2014-0170. DCN 08091.
Section 6—New Data Sources and Additional Supporting Analyses

6-19

48. U.S. EPA. 2011a. Final 2010 Effluent Guidelines Program Plan. Washington, D.C.

(October). EPA-HQ-OW-2008-0517-0575.

49. U.S. EPA. 2011b. Nanotechnology basic information. Available online at:

http://epa.gov/ncer/nano/questions/. EPA-HQ-OW-2014-0170. DCN 08092.

50. U.S. EPA. 2013a. Nanomaterials EPA is assessing. (February 12). Available online at:

http://www.epa.gov/nanoscience/quickfinder/nanomaterials.htm#carnan. EPA-HQ-OW2014-0170. DCN 08093.

51. U.S. EPA. 2013b. Nanoscale Materials Stewardship Program. Available online at:

http://epa.gov/oppt/nano/stewardship.htm. EPA-HQ-OW-2014-0170. DCN 08094.

52. U.S. EPA. 2013c. Response to Comments for the Final 2010 Effluent Guidelines

Program Plan. Washington, D.C. (May) EPA-HQ-OW-2010-0824-0196.

53. U.S. EPA. 2013d. Significant New Use Rules on Certain Chemical Substances.

Washington, D.C. (August 7). EPA-HQ-OPPT-2013-0399-0001.

54. U.S. EPA. 2013e. Significant New Use Rules on Certain Chemical Substances.

Washington, D.C. (June 26). EPA-HQ-OPPT-2010-0279-0134.

55. Unrine, J. M., P. Bertsch, O. Tsyusko, W.A. Shoults-Wilson, G.V. Lowry, B.P. Colman,

and E.S. Bernhardt. 2012. Fate and effects of silver nanoparticles in terrestrial

environments. Proceedings from the SETAC 33rd Annual Meeting, Long Beach,

California. (November 15). EPA-HQ-OW-2014-0170. DCN 08095.

56. Westerhoff, P., G. Song, K. Hristovski, and M.A. Kiser. 2011. Occurrence and removal

of titanium at full scale wastewater treatment plants: implications for TiO2 nanomaterials.

Journal of Environmental Monitoring. 13(5): 1195-1203.

www.dx.doi.org/10.1039/c1em10017c. EPA-HQ-OW-2014-0170. DCN 08096.

57. Westerhoff, P. K., M.A. Kiser, and K. Hristovski. 2013. Nanomaterial removal and

transformation during biological wastewater treatment. Environmental Engineering

Science. 30(3): 109-117. www.dx.doi.org/10.1089/ees.2012.0340. EPA-HQ-OW-2014-

0170. DCN 08097.

58. Wiesner, M. 2013. Telephone Communication between Mark Wiesner, Duke University,

and Eva Knoth and Kim Wagoner, Eastern Research Group, Inc. Re: Request for

Information on Nanomaterials Research.(March 13). EPA-HQ-OW-2014-0170. DCN

08098.

59. Wiesner, M. R., G.V. Lowry, E. Casman, P.M. Bertsch, C.W. Matson, R.T. Di Giulio, J.

Liu, and M.F. Hochella. 2011. Meditations on the ubiquity and mutability of nano-sized

materials in the environment. ACS Nano. 5(11): 8466-8470.

www.dx.doi.org/10.1021/nn204118p. EPA-HQ-OW-2014-0170. DCN 08099.
Section 6—New Data Sources and Additional Supporting Analyses

6-20 

60. Wiesner, M. R., G.V. Lowry, K.L. Jones, M.F. Hochella, R.T. Di Giulio, E. Casman, and 

E.S. Bernhardt. 2009. Decreasing uncertainties in assessing environmental exposure, risk, 

and ecological implications of nanomaterials. Environmental Science & Technology. 

43(17): 6458-6462. www.dx.doi.org/10.1021/es803621k. EPA-HQ-OW-2014-0170. 

DCN 08100. 

61. Yang, X., A.P. Gondikas, S.M. Marinakos, M. Auffan, J. Liu, H. Hsu-Kim, and J.N. 

Meyer. 2012. Mechanism of silver nanoparticle toxicity is dependent on dissolved silver 

and surface coating in Caenorhabditis elegans. Environmental Science & Technology. 

46(2): 1119-1127. www.dx.doi.org/10.1021/es202417t. EPA-HQ-OW-2014-0170. DCN 

08101. 

62. Zhang, Y., Y. Chen, P. Westerhoff, K. Hristovski, and J.C. Crittenden. 2008. Stability of 

commercial metal oxide nanoparticles in water. Water Research. 42(8–9): 2204-2212. 

EPA-HQ-OW-2014-0170. DCN 08102. 
Section 6—New Data Sources and Additional Supporting Analyses

6-21 

6.2 Review of Industrial Wastewater Treatment Technologies

The Clean Water Act (CWA) directs EPA to establish Effluent Limitations Guidelines 

and Standards (ELGs) based on the performance of particular treatment technologies, application 

of best management practices, or implementation of process changes. As described in EPA’s 

2002 Draft National Strategy (67 FR 71165), EPA considers several factors when developing its 

Effluent Guidelines Program Plans, including the availability of wastewater treatment 

technologies. EPA may choose to revise existing ELGs for a point source category if it identifies 

an applicable and demonstrated technology, process change, or pollution prevention approach 

that would reduce the concentrations of pollutants in the discharged wastewater and, 

consequently, reduce the hazard to human health or the environment associated with the 

pollutant discharges. 

Traditionally, EPA has reviewed the use and availability of improved treatment 

technologies when conducting specific facility, industry, and/or pollutant evaluations. In 2012, 

the Government Accountability Office (GAO) examined the Effluent Guidelines Program, 

including 1) the process EPA follows to screen and review industrial categories potentially 

needing new or revised guidelines, 2) any limitations to the process that could hinder EPA’s 

effectiveness in advancing CWA goals, and 3) EPA’s actions to address any such limitations 

(U.S. GAO, 2012). GAO’s review determined that EPA focused its screening phase on the 

hazards associated with industrial categories without considering the availability of treatment 

technologies or process changes that could reduce those hazards. As a result, GAO concluded 

that the screening phase of the process might exclude some industrial categories for which 

treatment technologies or production changes may be available to serve as the basis for new or 

revised effluent guidelines. 

EPA recognizes the need for a more coordinated approach to considering advances in 

treatment technologies across all industries as part of its initial screening of effluent guidelines. 

Furthermore, EPA believes it is important to consider technology advances when evaluating the 

effectiveness of older ELGs, some of which date back to the late 1970s or early 1980s. In some 

cases, more advanced treatment may be available that would allow EPA to establish ELGs for 

new pollutants or to strengthen existing requirements for regulated pollutants. As a result, in its 

Final 2012 and Preliminary 2014 Effluent Guidelines Program Plans (79 FR 55472), EPA 

announced that it had initiated a review of relevant literature to document the performance of 

new and improved industrial wastewater treatment technologies. This included plans to capture 

these performance data in a searchable Industrial Wastewater Treatment Technology (IWTT) 

Database. EPA intends to use IWTT as part of its annual reviews to quantify the effectiveness of 

technologies for removing pollutants of concern from specific industrial wastewater discharges. 

EPA will use the database, in part, to answer the following questions: 

• What new technologies or changes to existing technologies are specific industries

using to treat their waste streams?

• Are there technologies that can reduce or eliminate wastewater pollutants not 

currently regulated by ELGs, or remove pollutants to a greater degree than

industries currently achieve?
Section 6—New Data Sources and Additional Supporting Analyses

6-22 

The IWTT Database, which is responsive to GAO’s recommendation for the Effluent 

Guidelines Program, will be a critical tool for enhancing EPA’s ability to identify industrial 

categories or pollutants that warrant further review for new or revised ELGs, particularly based 

on improvements in treatment technologies. 

This section summarizes the literature EPA has evaluated to date for inclusion in IWTT, 

describes the database structure and data elements captured, and provides an overview and 

detailed output of the data collected thus far. The data collection methodology, data sources, data 

quality assurance and control criteria, and the proposed plan for data storage are described in 

detail in EPA’s 2012 Annual Effluent Guidelines Review Report (2012 Annual Review Report) 

(U.S. EPA, 2014a). 

6.2.1 Industrial Wastewater Treatment Technologies Data Collection Results

To date, EPA’s efforts to build and populate IWTT have included two literature reviews 

to collect information on wastewater treatment performance (U.S. EPA, 2014a). EPA first 

conducted a brief and general literature search for studies that documented pilot- or full-scale 

performance data for industrial wastewater treatment technologies in 2011. This initial literature 

search assessed the availability and quality of industrial treatment technology performance data. 

In addition, EPA evaluated the feasibility of developing a searchable database that it could use as 

a tool to screen industrial wastewater discharges based on advances in treatment.

As described in EPA’s 2012 Annual Review Report, a follow-on literature search in 2012 

and 2013 yielded more comprehensive wastewater treatment performance data related to a few 

key industries of interest (U.S. EPA, 2014a). These industries included petroleum refining (40 

CFR Part 419), metal finishing (40 CFR Part 433), and electroplating (40 CFR Part 413), as well 

as metals removal in general. Using the key words indicated in Appendix E, EPA reviewed data 

on new or improved treatment technology performance related to these industries from the 

following technical literature sources:

• Conference proceedings. EPA reviewed references from three key technical 

conferences on wastewater that included presentations across a broad range of 

industries: the Water Environment Federation’s Technical Exhibit and Conference 

(2000–2013), the International Water Conference (2011), and the Water 

Environment Federation’s Industrial Wastewater Seminar (2011). 

• Water-related journals. EPA reviewed peer-reviewed journal articles from waterrelated societies that may provide information on new, more effective industrial 

wastewater treatment technologies.

• Industry-specific organizations. EPA reviewed industry trade organization 

publications, such as treatment publications from the American Petroleum 

Institute and the American Chemical Society.

EPA screened all identified literature and data sources against the established data quality 

criteria described in Section 6.6.1.3 of the 2012 Annual Review Report (U.S. EPA, 2014a) and 

the Supplemental Quality Assurance and Control Plan for Development and Population of the 

Industrial Wastewater Treatment Database (ERG, 2013). 
Section 6—New Data Sources and Additional Supporting Analyses

6-23 

To date, EPA has identified and screened 283 articles. Of those, 163 met the quality 

criteria and were entered into IWTT (See Appendix F for a bibliography of the articles currently 

included in the database). Table 6-4 provides an overview of the number of industries 

represented in IWTT as well as the degree to which EPA has collected relevant literature 

describing new or improved treatment technologies. 

Table 6-4. Frequency of Industries Represented in IWTT 

Industry PSC Number of Articlesa

Petroleum refining 419 31

Metal finishing 433 21

Nonclassifiable establishments (industry not provided) -- 14

Coal mining 434 13

Oil and gas extraction 435 13

Steam electric power generating 423 11

Ore mining and dressing 440 9

Miscellaneous foods and beverages -- 9

Meat and poultry products 432 5

Pharmaceutical manufacturing 439 5

Pulp, paper and paperboard 430 4

Organic chemicals, plastics and synthetic fibers 414 4

Electrical and electronic components 469 3

Iron and steel manufacturing 420 3

Textile mills 410 3

Nonferrous metals manufacturing 421 3

Aluminum forming 467 2

Canned and preserved fruits and vegetables processing 407 2

Centralized waste treatment 437 2

Dairy products processing 405 2

Inorganic chemicals manufacturing 415 2

Grain mills 406 1

Fertilizer manufacturing 418 1

Mineral mining and processing 436 1

Hospital 460 1

Leather tanning and finishing 425 1

Transportation equipment cleaning 442 1

Agricultural services -- 1

CAFO 412 1

Wholesale trade - durable goods -- 1
Section 6—New Data Sources and Additional Supporting Analyses

6-24 

Table 6-4. Frequency of Industries Represented in IWTT 

Industry PSC Number of Articlesa

Airport deicing 449 1

Ferroalloy manufacturing 424 1

a Some articles may describe wastewater treatment technologies for more than one industry.

6.2.2 Industrial Wastewater Treatment Technologies Database Structure and Data Elements

IWTT captures wastewater treatment technology data identified from the reviewed data 

sources. This section describes the structure of the database and data elements in detail. EPA 

structured IWTT in Microsoft AccessTM to collect data on the following: 

• Treatment systems (i.e., treatment units included in the system, unit order, 

chemical additions, system operating conditions and costs, and process diagrams); 

• Industries implementing the technologies or industries for which the technology 

has been tested;

• Pollutants removed, including influent and effluent quality, and percent removals 

achieved; and

• Specific industry motivations for evaluating and employing new technologies. 

6.2.3 Database Structure 

EPA created several data tables in IWTT to organize article information and minimize 

redundancy and dependency within the database (ERG, 2013). Table 6-5 provides a brief 

description of the primary data input tables. EPA also established several lookup tables, which 

provide guidance or selection options for populating specific data input fields. Appendix H 

contains each of the key lookup tables. 

Table 6-5. List of Data Input Tables 

Table Name Table Description Where to Find More 

Information

Input Data (Data Obtained from the Articles)

1_INPUT_Reference_Information Contains article bibliographical information.

Export of IWTT Database 

Tables (ERG, 2014) 

2_INPUT_Treatment_Technology Contains information on treatment design, 

operations, and costs.

2_INPUT_Treatment_Technology

_Codes

Crosswalk between treatment technology 

operations codes and each treatment system 

reported.

3_INPUT_Detection_Limits Contains information on pollutant sample 

detection limits.

4_INPUT_Performance_Data Contains influent and effluent pollutant 

concentration data and percent removal.
Section 6—New Data Sources and Additional Supporting Analyses

6-25 

Table 6-5. List of Data Input Tables 

Table Name Table Description Where to Find More 

Information

Lookup

KEY_Document_Types Identifies the list of document types. Table H-2

KEY_Lab_Scale Identifies the scale in which the measurements 

were conducted.

Table H-3

KEY_Motivation Identifies the motivation categories for the 

implementation of the treatment system.

Table H-4

KEY_NAICS Identifies the NAICS code in which the 

treatment technology is used.

2012 NAICS Index File 

(U.S. Census, 2012)

KEY_PerformStat Identifies the value type reported (e.g., average,

minimum, maximum).

Table H-5

KEY_Parameter_Code Identifies the parameter names and Chemical 

Abstract Service (CAS) numbers. 

EPA DMR Pollutant 

Loading Tool (U.S. EPA, 

2014c)

KEY_PSCSIC_Crosswalk Identifies the PSCs and respective SIC codes. 2013 Annual Review Report 

Table B-1 (U.S. EPA, 

2014b)

KEY_TreatmentTechCode Identifies the treatment technology codes. Table H-6

EPA developed four data entry forms to facilitate data entry, promote standardization of 

data fields, and improve data security. The forms populate the corresponding fields in each of the 

input tables with relevant information. The purpose of each form is described below: 

• Form 0, “Main Menu.” Contains a listing of the existing articles entered into the 

database and allows data entry staff to edit an existing article entry or create a 

new article entry. Form 0 provides access to Form 1. 

• Form 1, “Reference Information.” Contains all of the data fields that identify and 

summarize the article reference, including bibliographical information, abstract, 

and key findings. Form 1 provides access to Form 2.

• Form 2, “Treatment Technology.” Contains all of the data fields that capture the 

treatment system design, unit order, operating conditions, and cost information. If 

an article discusses more than one treatment system, an additional Form 2 is 

populated for each system. Form 2 provides access to Form 3. 

• Form 3, “Removal Performance.” Contains all of the data fields that capture 

performance data for each parameter removed by each treatment system. If an 

article discusses the removal of more than one parameter, an additional Form 3 is 

populated for each parameter.

Figure 6-1 illustrates the overall database structure and navigation between the forms. 
Section 6—New Data Sources and Additional Supporting Analyses

6-26 

Figure 6-1. IWTT Structure

6.2.4 Data Elements Captured 

Table 6-6 below provides an overview of the type of specific information captured in 

IWTT. For a complete list and description of the captured data elements, see Table H-1. 

Table 6-6. Overview of Information Captured in IWTT

Form 1 Form 2 Form 3

Reference Information

Treatment Technology 

Information

Parameter Performance

• Title

• Publication year

• Number of pages

• Authors/affiliation

• Country

• Source (journal, publisher,

conference)

• Document type (e.g., conference 

proceedings, peer-reviewed

journal, government report)

• Abstract

• Key findings

• Motivation (e.g., effluent limits,

cost savings, water reuse, capacity

increase, environmental

impairment, resource recovery)

• Key parameters treated

• Relevant point source category,

SIC, and NAICS codes

• Scale (pilot or full)

• Treatment system units

comprising the system (in order of

the treatment train)

• Operating parameters (e.g., pH,

media)

• Narrative description of the

system

• Chemical additions required

• Notes on other relevant

parameters

• Process diagrams

• Wastewater discharge type (direct

or indirect, if identified)

• Pollutant parameter (each system

may have performance data for

multiple parameters)

• Analytical method (if identified)

• Influent and effluent detection

limits (if identified)

• Influent and effluent

concentrations and qualifier flags

(if identified)

• Reported percent removal (if

identified)

• Information about what the data

represent (e.g., average,

maximum, median)

• Effluent limits required for

discharge (if identified)
Section 6—New Data Sources and Additional Supporting Analyses

6-27 

Table 6-6. Overview of Information Captured in IWTT 

Form 1 Form 2 Form 3

Reference Information Treatment Technology 

Information Parameter Performance

• Type of wastestream (e.g., process 

wastewater, commingled 

stormwater and process water)

• Scale (lab, full, pilot)

• System manufacturer (if 

identified)

• Capital costs (if identified)

• Operation and maintenance costs 

(if identified)

6.2.5 Summary of Data Captured in IWTT 

EPA began populating IWTT in 2012 and continues to collect literature and populate the 

database. As of September 2014, there were 163 captured articles. While EPA focuses on 

capturing data about pilot- and full-scale treatment systems, it also documents limited 

information about lab-scale systems. Of the 163 articles, 98 have both treatment system 

information and pollutant removal information. Table 6-7 through Table 6-9 summarize the 

treatment technologies, industries, and parameters captured in the database. The spreadsheet 

IWTT_Export.xls provides a detailed output of the data captured in the IWTT Database (ERG, 

2014). 

EPA conducted specific quality assurance and control measures to validate the quality of 

the data as they were entered into IWTT. For more information on the quality assurance and 

control measures, see the methodology documented in the Supplemental Quality Assurance and 

Control Plan for the Development and Population of the Industrial Wastewater Treatment 

Database (ERG, 2013). 

There are currently 53 pilot- or full-scale treatment technologies captured in IWTT. Table 

6-7 lists the number of articles and treatment systems that include each technology. Twenty-eight 

treatment technologies, or 53 percent of those included in the database, are described in five or 

more articles. Appendix H provides additional reference tables on the treatment technologies. 

Table H-6 provides descriptions of each treatment technology. Table H-7 provides definitions of 

the treatment categories.

Table 6-7. Pilot- or Full- Scale Treatment Technologies Captured in IWTT

Treatment Technology Categorya Code Article Count Treatment

Systems Count

Chemical Precipitation Chemical ChemPre 32 42

Clarification Physical, NEC CLAR 25 29

Membrane Bioreactor Biological MBR 24 33

Flow Equalization Physical, NEC EQ 24 26

Membrane Filtration Membrane MF 19 25

Dissolved Air Flotation Physical, NEC DAF 19 25

Reverse Osmosis Membrane RO 18 20

Ion Exchange Chemical ION 16 20
Section 6—New Data Sources and Additional Supporting Analyses

6-28 

Table 6-7. Pilot- or Full- Scale Treatment Technologies Captured in IWTT

Treatment Technology Categorya Code Article Count Treatment 

Systems Count

Granular-Media Filtration Filtration FI 16 18

Mechanical Pre-Treatment Physical, NEC MPT 15 21

Aerobic Suspended Growth Biological ASG 13 13

Aeration Physical, NEC AIR 12 13

Bag and Cartridge Filtration Filtration BCF 9 10

Oil/Water Separation Physical, NEC OW 8 8

Anaerobic Fixed Film Biological 

Treatment Biological ANFF 7 11

Aerobic Fixed Film Biological Treatment Biological AFF 7 9

Electrocoagulation Physical, NEC EC 6 9

Anaerobic Biological Treatment Biological AND 6 8

Granular Activated Carbon Unit Sorption GAC 6 7

Liquid Extraction Chemical LE 6 7

UV Chemical UV 6 7

Adsorptive Media Sorption ADSM 6 6

Biologically Active Filters Biological BAC 6 6

Moving Bed Bioreactor Biological MBBR 6 6

Evaporation Physical, NEC EVAP 5 10

Constructed Wetlands Biological WET 5 8

Aerobic Biological Treatment Biological AD 5 6

Biological Nutrient Removal Biological BNR 5 5

Advanced Oxidation Processes, NEC Chemical AOP 4 4

Chemical Oxidation Chemical CO 3 4

Stripping Physical, NEC ST 3 4

Chemical Disinfection Chemical CD 3 3

Ballasted Clarification Physical, NEC BCLAR 3 3

Degasification Physical, NEC DGS 3 3

Nanofiltration Membrane NANO 3 3

Crystallization Physical, NEC CYS 2 7

Centrifugal Separator Physical, NEC CS 2 3

Anaerobic Suspended Growth Biological ANSG 2 2

Biological Treatment Biological BIO 2 2

Controlled Hydrodynamic Cavitation Physical, NEC CHC 2 2

Denitrification Filters Biological FDN 2 2

Ozonation Chemical OZ 2 2

Powdered Activated Carbon Sorption PAC 2 2

Dechlorination Chemical DCL 2 2

Hydrolysis, Acid or Alkaline Chemical AKH 1 2

Cloth Filtration Filtration CF 1 1

Biofilm Airlift Suspension Reactor Biological BASR 1 1
Section 6—New Data Sources and Additional Supporting Analyses

6-29 

Table 6-7. Pilot- or Full- Scale Treatment Technologies Captured in IWTT

Treatment Technology Categorya Code Article Count Treatment 

Systems Count

Zero Valent Iron Chemical ZVI 1 1

Anaerobic Membrane Bioreactor Biological AnMBR 1 1

Dissolved Gas Flotation Physical, NEC DGF 1 1

Distillation Physical, NEC DST 1 1

Granular Sludge Sequencing Batch 

Reactor Biological GSBR 1 1 

Integrated Fixed-Film Activated Sludge Biological IFAS 1 1

a See Table H-7 for descriptions of each category.

Table 6-8 presents the number of full- and pilot-scale systems that have performance data 

for the industries captured in IWTT. Of the 163 articles entered in the database, 98 have 

wastewater treatment system and performance data for end-of-pipe treatment (i.e., parameter 

influent concentration, effluent concentration, and/or percent removal). IWTT captured removal 

performance of 142 parameters for these wastewater treatment systems. Table 6-9 lists the 

parameters with the greatest number of systems for which EPA documented treatment 

performance. Table G-1, in Appendix G presents the complete list of parameters with 

documented treatment performance. 

Table 6-8. Industries with Performance data in IWTT

Industry PSC Scale of Treatment 

System

Number of Treatment 

Systems

Dairy products processing 405 Full 1

Canned and preserved fruits and vegetables processing 407 Full 1

Textile mills 410 Pilot 2

CAFO 412 Full 2

Petroleum refining 419

Full 6

Pilot 12

Iron and steel manufacturing 420 Pilot 1

Nonferrous metals manufacturing 421 Pilot 3

Steam electric power generating 423

Full 1

Pilot 3

Ferroalloy manufacturing 424 Pilot 1

Leather tanning and finishing 425 Full 4

Pulp, paper and paperboard 430 Pilot 1

Meat and poultry products 432

Full 4

Pilot 2

Metal finishing 433

Full 2

Pilot 18

Coal mining 434

Full 2

Pilot 7
Section 6—New Data Sources and Additional Supporting Analyses

6-30 

Table 6-8. Industries with Performance data in IWTT

Industry PSC Scale of Treatment 

System

Number of Treatment 

Systems

Oil and gas extraction 435

Full 2

Pilot 8

Centralized waste treatment 437 Full 1

Pharmaceutical manufacturing 439

Full 1

Pilot 1

Ore mining and dressing 440

Full 1

Pilot 2

Transportation equipment cleaning 442 Full 1

Hospital 460 Pilot 1

Aluminum forming 467 Full 1

Electrical and electronic components 469 Pilot 2

Agricultural services -- Pilot 1

Miscellaneous foods and beverages -- Full 3

Pilot 6

Nonclassifiable establishments -- Full 1

Pilot 5

Table 6-9. Top Parameters with Performance Data in IWTT 

Parametera Frequency

Chemical oxygen demand 43

Total suspended solids 38

BOD 21

Solids, total dissolved (TDS) 17

Carbon, total organic (TOC) 13

Chemical oxygen demand, total 12

Nickel 12

Phosphorus, total 12

Conductivity 11

Chloride 11

Oil and grease 10

Selenium, total 10

Ammonia (as NH3) 10

Nitrogen, total 10

Cadmium 10

Chromium 9

Ammonia (as N) 9

Copper 9
Section 6—New Data Sources and Additional Supporting Analyses

6-31 

Table 6-9. Top Parameters with Performance Data in IWTT 

Parametera Frequency

Zinc 9

Sulfate 9

BOD5 9

Nitrogen, Kjeldahl total (TKN) 9

Calcium 8

Turbidity 8

Iron 7

Fats, oils and grease (FOG) 7

Ammonia, total 6

Nitrate (as N) 6

Arsenic 6

Dissolved oxygen (DO) 6

Naphthenic acid 5

Phenol 5

Nitrate 5

Magnesium 5

Ammonia-nitrogen 5

Phosphorus 5

Solids, volatile suspended 5

Chromium, hexavalent 5

Chemical oxygen demand, soluble 5

Selenium 5

Sodium 5

a Parameter names are only as specific as the names stated in each article.

6.2.6 References for the Review of Industrial Wastewater Treatment Technologies

1. ERG. 2013. Eastern Research Group, Inc. Supplemental Quality Assurance and Control 

Plan for the Development and Population of the Industrial Wastewater Treatment 

Technology Database. Chantilly, VA. (November 22). EPA-HQ-OW-2010-0824-0263. 

2. ERG. 2014. Eastern Research Group, Inc. Export of Industrial Wastewater Treatment 

Technology (IWTT) Database Tables. Chantilly, VA. (September). EPA-HQ-OW-2014-

0170. DCN 08000. 

3. U.S. Census. 2012. 2012 NAICS Index File. Available online at: 

http://www.census.gov/cgi-bin/sssd/naics/naicsrch?chart=2012. EPA-HQ-OW-2014-

0170. DCN 08001. 

4. U.S. EPA. 2014a. The 2012 Annual Effluent Guidelines Review Report. Washington, 

D.C. (September). EPA-821-R-14-004. EPA-HQ-OW-2010-0824-0320. 
Section 6—New Data Sources and Additional Supporting Analyses

6-32 

5. U.S. EPA. 2014b. The 2013 Annual Effluent Guidelines Review Report. Washington, 

D.C. (September). EPA-821-R-14-003. EPA-HQ-OW-2014-0170-0077. 

6. U.S. EPA. 2014c. DMR Pollutant Loading Tool. DMR Pollutant Parameters Used and 

Not Used by the Loading Tool (CSV). Available online at: 

http://cfpub.epa.gov/dmr/technical-support-documents.cfm. Accessed: June 24, 2014. 

EPA-HQ-OW-2014-0170. DCN 08002. 

7. U.S. GAO. 2012. United States Government Accountability Office. Water Pollution: 

EPA Has Improved Its Review of Effluent Guidelines but Could Benefit from More 

Information on Treatment Technologies. (September). EPA-HQ-OW-2010-0824 -0264. 
III

PART III: RESULTS OF EPA’S 2014 ANNUAL REVIEW
Section 7—Results of the 2014 Annual Review

7-1 

7. RESULTS OF THE 2014 ANNUAL REVIEW

For the 2014 Annual Review, EPA evaluated public comments and stakeholder input 

received on the Preliminary 2014 Effluent Guidelines Program Plan, and initiated its review of 

industrial categories identified as warranting further investigation during the previous annual 

reviews (U.S. EPA, 2014). Additionally, EPA initiated a review of an emerging pollutant group 

of concern and continued its review of industrial wastewater treatment technology performance 

data. This section presents a summary of the findings from the 2014 Annual Review. 

7.1 Continued Review of Select Industrial Categories

During previous annual reviews, EPA identified several industrial categories warranting 

further review: Metal Finishing (40 CFR Part 433), Pesticide Chemicals (40 CFR Part 455), and 

brick and structural clay products manufacturing (not currently regulated). EPA continued its 

review of these categories as part of the 2014 Annual Review. Below are the findings from the 

2014 continued category reviews. 

• Continued Review of the Metal Finishing Category (40 CFR Part 433). EPA’s 

continued review of the Metal Finishing Category in 2014 indicates that the 

industry has not experienced significant growth in the last 30 years. However, 

research suggests that the industry is consolidating into larger companies that tend 

to compete better with the expanding global market. This consolidation may have 

slightly reduced the size of the U.S. metal finishing industry. Further, the industry 

is exploring the use of new chemicals that improve surface finishing quality 

and/or eliminate the need for toxic chemicals that generate wastewater requiring 

further treatment to meet discharge requirements. These alternatives may be 

changing the characteristics of metal finishing wastewater over time. In addition, 

at least some portion of the industry is employing more advanced wastewater 

treatment technologies, including reuse, although a majority of the industry 

continues to meet the effluent limitations guidelines and standards (ELGs) using 

the more common treatment technologies, based on best available technology 

economically achievable as defined in the ELGs. 

EPA’s continued preliminary review of the Metal Finishing Category identified several 

topics that warrant further review, including: 

• Potential new pollutants of concern not currently regulated that are increasingly 

used in metal finishing processes. 

• Prevalence of potential pollutants of concern associated with wastewater 

generated from the use of wet air pollution control devices to control air 

emissions from metal finishing operations.

• The application of advanced wastewater treatment technologies and the 

prevalence of zero discharge practices in the industry. 
Section 7—Results of the 2014 Annual Review

7-2 

• In addition there are several questions that are often raised regarding the 

applicability of the metal finishing requirements, such as the distinction between 

cleaning and etching of the base material. 

• Targeted Review of Pesticide Active Ingredients (PAIs) without Pesticide 

Chemical Manufacturing Effluent Limits (40 CFR Part 455). EPA’s 2014 review 

identified that only seven of the 30 PAIs of interest for which discharges from 

manufacturing are not currently regulated under 40 CFR Part 455 are currently 

registered or are under registration review in accordance with Section 3 of 

FIFRA. The remaining 23 PAIs of interest have either never been registered or 

have had their registrations canceled. However, discussions with EPA’s Office of 

Pesticide Programs suggested that registration status may not be an indicator of 

whether the PAI is manufactured in the U.S. (and hence potentially present in 

industrial wastewater discharge), as unregistered pesticides may still be 

manufactured in the U.S. for export. Therefore, based on the information 

reviewed in 2014, EPA was not able to prioritize for further review a subset of the 

PAIs of interest that are produced in the U.S. However, EPA did identify several 

follow-up questions and sources of information that will indicate whether any of 

the PAIs of interest are produced in the U.S. and are thus potentially present in 

industrial wastewater discharge. These sources of information include the 

Pesticide Registration Information System (PRISM), Section Seven Tracking 

System (SSTS) production data, and permit applications, fact sheets, and facility 

permits for producers of the PAIs in the U.S. 

• Continued Review of Brick and Structural Clay Products Manufacturing. EPA’s 

review of the current National Emission Standards for Hazardous Air Pollutants 

(NESHAP) for the brick and structural clay products manufacturing industry, and 

discussions with EPA’s Office of Air and Radiation and the Brick Industry 

Association, identified only two of the 345 brick manufacturing facilities, two of 

the 24 clay ceramics facilities, and three of 127 ceramic tile facilities in the U.S. 

as currently having wet scrubbers installed. The findings suggest that the use of 

wet scrubbers to control air pollution is limited in this industry; therefore, the 

brick and structural clay products manufacturing industry is not generating a 

potential new source of industrial wastewater discharge that warrants regulation. 

7.2 New Data Sources and Additional Supporting Analyses 

EPA initiated a review of emerging pollutants of concern and continued its review of 

industrial wastewater treatment technology performance data as part of the 2014 Annual Review. 

Below are the findings from these analyses.

• Review of Engineered Nanomaterials (ENMs) in Industrial Wastewater. EPA 

identified outstanding data gaps related to characterizing and quantifying the 

presence and impact of ENMs in industrial wastewater discharges. EPA focused 

its review on three classes on ENMs: silver, titanium dioxide, and carbon-based 

nanomaterials. These are estimated to be produced in the largest volumes, and 

research has more fully classified their impacts on human health and the 
Section 7—Results of the 2014 Annual Review

7-3 

environment relative to the impacts of other types of ENMs (for which there is 

little information). EPA’s review determined the following:

— Some ENM manufacturing and processing methods likely generate 

wastewater, but the quantity generated and waste management practices 

are not documented. 

— Toxicity hazards from ENMs have been demonstrated, but the 

environmental and human health risks are largely unknown. 

— Fate and exposure to industrial wastewater releases of ENMs to the 

environment have not been studied. 

— The small size, unique properties, and complexity of ENMs present a 

challenge for environmental monitoring, risk assessment, and regulation. 

— Methods for detecting and characterizing nanomaterials in complex media 

like industrial wastewater are under development.

— EPA has not approved any standardized methods for sampling, detecting, 

or quantifying nanomaterials in aqueous media.

— Research has shown that common treatment technologies employed at 

municipal wastewater treatment plants are effective at removing 

nanomaterials from the wastewater.

• From its review of the current body of research, EPA has identified several areas 

of further research appropriate to better assess the potential presence and impact 

of ENMs in industrial wastewater. Much of this research may be addressed by 

ongoing academic and government research, including research coordinated 

through the National Nanotechnology Initiative. 

• Review of Industrial Wastewater Treatment Technologies. From its review of 

literature regarding the performance of industrial wastewater treatment 

technologies, EPA has identified and captured treatment information from 163 

articles in its IWTT Database, as of September 2014. Of the 163 articles, 98 

provide both treatment system information and performance data (i.e., pollutant 

removal efficiencies). The 98 articles with performance data represent 35

industrial categories; however most of the literature reviews conducted to date 

have focused on collecting treatment technology information for the petroleum 

refining and metal finishing industries. IWTT documents the removal efficiencies 

relating to 142 parameters, including many metals, chemical oxygen demand, 

total suspended solids, and total dissolved solids. Though performance data are 

captured for pilot- and full-scale treatment systems as a whole, 53 individual 

treatment technologies (which constitute the various treatment systems) are 

currently included in IWTT, with chemical precipitation, membrane bioreactors, 

and clarification described in the greatest number of articles.
Section 7—Results of the 2014 Annual Review

7-4

7.3 References for Results of the 2014 Annual Review

1. U.S. EPA. 2014. Final 2012 and Preliminary 2014 Effluent Guidelines Program Plans.

Washington, D.C. (September). EPA-820-R-14-001. EPA-HQ-OW-2014-0170-0002.