MEMORANDUM 

TO: Melissa Weitz, EPA 

FROM: Amie Aguiar and Deb Bartram, ERG 

 DATE: 10 August 2008 

 SUBJECT: Planned Revisions of the Industrial Wastewater Inventory Emission 

Estimates for the 1990-2007 Inventory

As directed by EPA, ERG will be incorporating a number of previously proposed revisions to the 

industrial wastewater inventory emission estimates. This memorandum presents a summary of 

the planned improvements. 

I ESTIMATING PETROLEUM REFINING WASTEWATER TREATMENT EMISSIONS

As outlined in the memorandum from 30 July 2008 on petroleum refining coverage in the 

Inventory, ERG recommends including the petroleum refining industry in the wastewater sector. 

The previous memorandum explicitly outlines the methods and calculations for estimating CH4

and CO2 emissions from wastewater treatment systems. 

II REFINING CALCULATION METHOD TO INCLUDE BOD/COD REMOVAL PRIOR TO 

ANAEROBIC TREATMENT

With the exception of pulp and paper wastewater treatment, the inventory method currently does 

not explicitly account for BOD or COD removals that may occur prior to the anaerobic treatment 

of the wastewater. The 2006 IPCC Guidelines suggests that the removal of organics as sludge be 

addressed as shown in the following equation: 

CH4 Emissions =   i

REFSTOW iiii [( )

Where: 

CH4 Emissions = CH4 emissions in inventory year, kg CH4/yr 

TOWi = total organically degradable material in wastewater from industry i 

 in inventory year, kg COD/yr

i = industrial sector 

Si = organic component removed as sludge in inventory year, kg 

 COD/yr 

EFi = emission factor for industry i, kg CH4/kg COD for 

 treatment/discharge pathway or system(s) used in inventory year 

Ri = amount of CH4 recovered in inventory year, kg CH4/yr 
Memorandum 

10 August 2008 

Page 2 

Therefore, ERG investigated the appropriateness of including a factor for the Inventory’s 

industry categories to account for BOD/COD that is removed through primary treatment and 

therefore does not contribute to methane emissions. Table 1 presents a summary of the 

suggested actions for the 1990-2007 U.S. Inventory. 

Pulp and Paper

As described in ERG’s memorandum entitled “Recommended Improvements to EPA’s 

Wastewater Inventory for Industrial Wastewater,” dated July 2, 2007, ERG previously estimated 

the percent of BOD that would be removed in primary treatment at a pulp mill. In the United 

States, primary treatment is focused on solids removal, equalization, neutralization, and color 

reduction (EPA, 1993). The vast majority of pulp and paper mills with on-site treatment systems 

use mechanical clarifiers to remove suspended solids from the wastewater. ERG estimated that 

approximately 42 percent of the BOD in pulp and paper wastewater passes on to secondary 

treatment, which consists of activated sludge, aerated stabilization basins, or non-aerated 

stabilization basins. 

Meat and Poultry

For meat and poultry plants, primary wastewater treatment is commonly used prior to the onsite 

anaerobic lagoon. Raw wastewater from slaughterhouses can include suspended matter that is 

insoluble, is slowly biodegradable, and accounts for 40 to 50 percent of the raw wastewater 

COD. Most facilities use screening, oil and grease removal, dissolved air flotation, and flow 

equalization. However, the BOD/COD value used in the Inventory represents the amount of 

BOD/COD entering the anaerobic lagoon following primary treatment. Therefore, it is not 

necessary to add a specific factor for this industry to account for BOD/COD removals during 

primary treatment. 

Fruits and Vegetables

For fruits and vegetables processing plants, screening is used at almost all canning plants, while 

gravity sedimentation is used at all types of plants. Gravity sedimentation is a primary treatment 

operation to reduce suspended solids and BOD, with the sludge being pumped to sludge handling 

or digestion facilities. The efficiency of the primary settling step to reduce BOD is dependent on 

the specific type of waste (e.g., tomato and tree fruit lye peel wastewater vs. root crop vegetable 

wastewater). Based on data collected by EPA (EPA, October 1975), BOD is typically reduced by 

17 to 30 percent. Therefore, ERG suggests including a BOD removal rate of 23 percent. 

Ethanol Production

As described in ERG’s memorandum entitled “Assessment of Greenhouse Gas Emissions from 

Wastewater Treatment of U.S. Ethanol Production Wastewaters,” dated October 19, 2006, the 

COD loading used in the inventory represents the amount of BOD/COD expected to enter the 
Memorandum 

10 August 2008 

Page 3 

anaerobic treatment systems. Therefore, it is not necessary to add a specific factor for this 

industry to account for BOD/COD removals during primary treatment. 

Petroleum Refining

Petroleum refineries utilize oil/water separators as a primary treatment operation. ERG was 

unable at this time to determine specific removal rates for BOD/COD by these primary treatment 

operations. However, we believe there is no significant removal. 

Table 1. Primary Treatment and Percent BOD Removal by Industry 

Industry Primary Treatment 

Presence % BOD Removal in Primary Treatment 

Pulp and Paper Yes 58% 

Meat and Poultry Yes No Factor Needed (BOD represents what is entering 

anaerobic lagoon) 

Fruits and Vegetables Yes 23% 

Ethanol Production No No Factor Needed (BOD represents what is entering 

anaerobic treatment) 

Petroleum Refining Yes No significant BOD removal expected 

III ESTIMATING PERCENT INDUSTRIAL WASTEWATER TREATED ON SITE AND NUMBER OF 

TREATMENT SYSTEMS

In ERG’s memorandum entitled “Estimation of Onsite Treatment at Industrial Facilities and 

Review of Wastewater Characterization Data,” dated 15 April 2008, ERG reviewed the number 

of treatment systems and the percent of wastewater treated onsite. Using this industry-specific 

information, ERG will revise the inventory calculations to present the estimation of percent 

wastewater treated anaerobically (%TA) for each industry. We will present a general calculation 

for each industry that defines the percent of plants in the industry that treat wastewater on site, 

the percent of plants that have a primary treatment step prior to biological treatment, and the 

percent of plants that treat wastewater anaerobically. ERG will estimate the %TA for both 

primary treatment and secondary treatment. For plants that have primary treatment in place, 

ERG will incorporate an estimate of COD that is removed prior to wastewater treatment in the 

anaerobic treatment units. 

In general, ERG recommends the industry equations be revised to show the following 

calculations for the percent of wastewater treated anaerobically (%TA): 

%TAp = %Plantso * %WWa,p * %CODp 

%TAs = [%Plantsa * %WWa,s * %CODs] + [%Plantst * %WWa,t * %CODs] 
Memorandum 

10 August 2008 

Page 4 

Where: 

%TAp = percent of industry wastewater treated anaerobically in primary treatment 

%Plantso = percent of plants with onsite treatment 

%WWa,p = percent of wastewater treated anaerobically in primary treatment 

%CODp = percent of COD entering primary treatment 

%TAs = percent of industry wastewater treated anaerobically in secondary 

 treatment 

%Plantsa = percent of plants with anaerobic secondary treatment 

%Plantst = percent of plants with other secondary treatment 

%WWa,s = percent of wastewater treated anaerobically in anaerobic secondary 

 treatment 

%WWa,t = percent of wastewater treated anaerobically in other secondary treatment 

%CODs = percent of COD entering secondary treatment 

Pulp and Paper

Based on information from the 2002 U.S. Economic Census, there are 561 pulp and paper mills 

in the United States. According to EPA’s data from 1993, there were a total of 565 pulp and 

paper mills. Of these, 338 mills (60%) have onsite treatment with primary treatment and 166 

mills (approximately 30%) have basins for secondary wastewater treatment (either aerated or 

nonaerated). About 85% of these basins are anaerobic (or 25% of plants have anaerobic basins 

on site). 

Meat and Poultry

According to the 2002 U.S. Economic Census there are 3,973 meat and poultry processing 

facilities in the United States, of which 3,437 are red meat facilities and 536 are poultry plants. 

EPA conducted a survey in 2001 to collect information on the industry based on calendar year 

2000. From that information, EPA estimates that 71% of facilities discharge wastewater, of 

which 94% are indirect dischargers (facilities that discharge to a publicly owned treatment works 

(POTW)) and 6% are direct dischargers. Overall, EPA estimates that 67% of meat processing 

facilities discharge indirectly and 75% of poultry operations discharge indirectly. Although it is 

likely that most of the indirect dischargers employ some pretreatment such as screening and 

dissolved air floatation, anaerobic pretreatment would be unusual. 

The remaining facilities either do not discharge (“zero discharger”) or they discharge their 

wastewater directly. All direct dischargers utilize anaerobic treatment; however, there is limited 

information on zero dischargers. Although it is likely that some small zero discharge facilities 

use contract haulers for wastewater disposal, it seems reasonable to assume that zero discharge 

generally means disposal by land application preceded by anaerobic pretreatment given the lack 

of available information. 
Memorandum 

10 August 2008 

Page 5 

Therefore, we estimate all meat and poultry processing facilities conduct some sort of treatment 

on site. Approximately 33% of meat wastewater and 25% of poultry wastewater is treated 

anaerobically on site. 

Fruits and Vegetables

According to the 2002 U.S. Economic Census for Manufacturing, there are 1,746 fruit and 

vegetable preserving and specialty plants. Of all fruit facilities, 52% discharge to POTWs, 11.6% 

directly discharge to surface waters, and 36.6% land apply their wastewater. At vegetable 

facilities, 48% of wastewater is discharged to POTWs, 11% is directly discharged to surface 

waters, and 41% is land applied. So for fruit and vegetable facilities together, roughly 50% is 

discharged to POTWs (873 facilities), 11% is directly discharged (192 facilities), and 39% is 

land applied (681 facilities; Martin 2006). 

It is reasonable to assume that, depending on the product, approximately 50% of all direct 

discharge is pretreated in anaerobic lagoons. Facilities discharging to POTWs or land applying 

their wastewater are unlikely to have any anaerobic pretreatment, so it is likely that 

approximately 96 facilities treat their wastewater anaerobically on site (Martin 2006). The 

current Inventory states that 5% of wastewater is treated anaerobically on site, which translates 

to about 87 facilities, which is close to the values calculated above. 

Ethanol Production

In the United States, there are currently 139 ethanol biorefineries with 61 under construction 

(RFA, 2008). From the Inventory, 23% of these refineries are wet milling facilities and 77% are 

dry milling facilities (about 32 and 107, respectively). As described in ERG’s memorandum 

entitled “Assessment of Greenhouse Gas Emissions from Wastewater Treatment of U.S. Ethanol 

Production Wastewaters,” dated October 19, 2006, 33.3% of wastewater is treated anaerobically 

at wet milling facilities. This can be translated to about 11 facilities that treat wastewater 

anaerobically on site. At dry milling facilities, 75% of wastewater is treated anaerobically on site 

(in either biomethanators or other anaerobic systems). Biomethanators account for 50%, and 

other anaerobic treatment counts for 25%.1

 In total, roughly 80 dry milling facilities treat 

wastewater anaerobically, with 53 treating their wastewater with biomethanators. 

Summary of Industry Values

Based on the previous discussions, ERG recommends using the values presented in Table 2 in 

the revised Inventory calculations. 

 

1

 These percentages for dry milling operations have been updated since the October 19, 2006 memorandum to 

account for additional industry contacts made in January 2007. 
Memorandum 

10 August 2008 

Page 6 

Table 2. Variables Needed to Calculate Percent Treated Anaerobically by Industry 

Industry 

Variable Pulp and 

Paper 

Meat 

Processing 

Poultry 

Processing 

Fruit/ 

Vegetable 

Processing 

Ethanol 

Production 

– Wet Mill 

Ethanol 

Production 

– Dry Mill 

Petroleum 

Refining 

%TAp 0 0 0 0 0 0 0 

%TAs 10.5 33 25 5.5 33.3 75 100 

%Plantso 60 100 100 11 100 100 100 

%Plantsa 25 33 25 5.5 33.3 75 100 

%Plantst 35 67 75 5.5 66.7 25 0 

%WWa,p 0 0 0 0 0 0 0 

%WWa,s 100 100 100 100 100 100 100 

%WWa,t 0 0 0 0 0 0 0 

%CODp 100 100 100 100 100 100 100 

%CODs 42 100 100 100 100 100 100 

IV UPDATING ETHANOL PRODUCTION WASTEWATER EMISSIONS CALCULATIONS

ERG will be confirming ethanol calculations using EPA ethanol plant site visit data from KarrieJo Robinson-Shell from EPA Region 4. ERG is currently awaiting receipt of these data and plans 

to confirm or improve the following variables: the volume of water generated per unit of ethanol 

production, types of treatment units used and data on BOD or COD in wastewater prior to 

treatment. 

V INCLUSION OF OTHER INDUSTRIAL WASTEWATER SOURCES

The methodology to estimate emissions for industrial wastewater currently accounts for pulp and 

paper, meat and poultry processing, fruits and vegetables processing, and ethanol production 

wastewater treatment. Based on direction from the EPA TOPO for the 1990-2007 Inventory, 

ERG will also add petroleum refining wastewater treatment. To support EPA in determining 

whether other industrial sources should be included in the wastewater inventory, ERG used 

available data sets from EPA’s Permit Compliance System (PCS) to investigate/rank other 

industries based on the amount of BOD, COD, and total nitrogen reported to be discharged. 

For industries that report discharging large quantities of BOD and COD, ERG then investigated 

whether these facilities are likely to treat their wastewater on site with anaerobic biological 

treatment, indicating a likelihood of methane generation from treatment. For industries that 

report discharging large quantities of total nitrogen, ERG investigated whether these facilities are 

likely to treat their wastewater on site with nitrification/denitrification biological systems, 

indicating a likelihood of nitrous oxide generation from treatment. These facilities are likely to 

also produce nitrous oxide from their discharged effluent. 
Memorandum 

10 August 2008 

Page 7 

Background Information on EPA’s Permit Compliance System

PCS is a computerized information management system maintained by EPA’s Office of 

Enforcement and Compliance Assurance (OECA). It was created to track permit, compliance, 

and enforcement status of facilities regulated by the NPDES program under the CWA. Among 

other things, PCS houses discharge data for these facilities. More than 65,000 industrial facilities 

and wastewater treatment plants have permits for wastewater discharges to waters of the United 

States. 

To provide an initial framework for setting permitting priorities, EPA developed a major/minor 

classification system for industrial and municipal wastewater discharges. Major discharges 

almost always have the capability to impact receiving waters if not controlled and, therefore, 

have received more regulatory attention than minor discharges. There are approximately 6,400 

facilities (including POTWs) with major discharges for which PCS has extensive records. 

Permitting authorities classify discharges as major based on an assessment of six characteristics: 

1. Toxic pollutant potential; 

2. Discharge flow: stream flow ratio; 

3. Conventional pollutant loading; 

4. Public health impact; 

5. Water quality factors; and 

6. Proximity to coastal waters. 

Facilities with major discharges must report compliance with NPDES permit limits via monthly 

Discharge Monitoring Reports (DMRs) submitted to the permitting authority. The permitting 

authority enters the reported DMR data into PCS, including pollutant concentration and quantity 

values and identification of any types of permit violations. Minor discharges may, or may not, 

adversely impact receiving water if not controlled. Therefore, EPA does not require DMRs for 

facilities with minor discharges. For this reason, the PCS database includes data only for a 

limited set of minor dischargers when the states choose to include these data. 

Parameters in PCS include water quality parameters (such as pH and temperature), specific 

chemicals, conventional parameters (such as BOD5 and total suspended solids [TSS]), and flow 

rates. Although other pollutants may be discharged, PCS contains only data for the parameters 

identified in the facility’s NPDES permit. Facilities typically report monthly average pounds per 

day discharged, but also report daily maxima and average pollutant concentrations. 

The PCS database contains approximately 50 different parameters that may be reported for 

nitrogen compounds. Total nitrogen is the sum of organic nitrogen, ammonia, nitrite, and nitrate. 

Total inorganic nitrogen is the sum of ammonia, nitrite, and nitrate. Total Kjeldahl Nitrogen 

(TKN) is the sum of organic nitrogen and ammonia. Unionized ammonia is a subset of total 

ammonia. Because different nitrogen compounds reported by one facility may overlap with each 

other, ERG developed the following hierarchy for calculating the total nitrogen load to avoid 

double counting nitrogen: 
Memorandum 

10 August 2008 

Page 8 

1. Use PCS PRAM 00600 (“Nitrogen, Total (as N)), if reported, to represent total nitrogen. 

2. If PCS PRAM 00600 is not reported, use the sum of TKN, nitrite, and nitrate. 

3. If neither of the first two rules apply, use the sum of organic nitrogen, ammonia, nitrite, 

nitrate. 

4. Where applicable, use TRI data to fill in for missing PCS parameters in the total nitrogen 

calculation. 

5. If no nitrogen compounds are reported to PCS, use the sum of ammonia, sodium nitrite, 

and nitrate compounds reported to TRI. 

Loads of compounds that are not reported as nitrogen, such as sodium nitrite, nitrate compounds, 

or ammonia, were converted to pounds of nitrogen using the following equation: 

Lbs Nitrogen = Lbs Compound * (Molecular Weight (MW) Nitrogen / MW Compound) 

ERG, in support of EPA Office of Water’s Effluent Guidelines Program Plan, used the PCS data 

for reporting year 2004 to estimate annual pollutant loads by industry category. ERG used a 

calculation tool called the PCSLoadCalculator to calculate these annual loads. The output from 

this tool is housed in a database called PCSLoads2004. More details on the methodology and 

development PCSLoads2004 can be found in EPA’s 2008 Preliminary Plan TSD (EPA, 2007). 

Industry Rankings

ERG used the industry rankings of BOD, COD, and total nitrogen discharges from 

PCSLoads2004 to determine the top five industries for each pollutant parameter. The full lists of 

industry rankings can be found in Attachments 1 through 3. Table 3 presents a summary of the 

industries with the highest loads for each of these parameters. It’s important to note that a 

majority of plants are required to monitor and report BOD discharges; a smaller percentage are 

required to report COD and/or nitrogen loadings. However, the organic chemicals, plastics, and 

synthetic fibers (OCPSF) industry is listed as one of the top five industries discharging all three 

pollutant parameters for 2004. Therefore, ERG further investigated this industry for possible 

inclusion in the U.S. Greenhouse Gas Inventory. 
Memorandum 

10 August 2008 

Page 9 

Table 3. Top Industries Reporting Discharges of BOD, COD, and Total Nitrogen in 2004 

Reported BOD Discharges Reported COD Discharges Reported Nitrogen Discharges 

Industry Total Annual 

Load Industry Total Annual Load Industry Total Annual Load 

Organic 

chemicals, 

plastics and 

synthetic fibers 

1,415,153,620 Pulp, paper and 

paperboard 147,340,464 

Organic 

chemicals, 

plastics and 

synthetic fibers 

14,709,505 

Chlorine and 

chlorinated 

hydrocarbons 

662,227,060 Petroleum 

refining 134,104,025 Steam electric power generation 12,517,688 

Pulp, paper and 

paperboard 242,941,593 Textile mills 30,591,292 Meat and Poultry Products 9,175,593 

Canned and 

preserved 

seafood 

processing 

51,815,923 

Organic 

chemicals, 

plastics and 

synthetic fibers 

25,678,477 Pulp, paper and 

paperboard 9,124,065 

Steam electric 

power 

generating 

51,520,861 

Miscellaneous 

Foods and 

Beverages 

16,984,927 Fertilizer 

manufacturing 6,166,094 

Preliminary Investigation of the OCPSF Industry

The OCPSF category includes many chemical industries producing hundreds of end products, 

such as polypropylene, vinyl chloride and PVC, chlorinated solvents, rubber precursors, 

styrofoam additives, and polyester (to name a few). Some OCPSF facilities are extremely 

complex and produce hundreds of chemicals, where others are simpler, producing only one or 

two. This category includes facilities in the following SIC codes: 

• 2821: Plastic Materials, Synthetic Resins, and Nonvulcanizable Elastomers; 

• 2823: Cellulosic and Other Man-Made Fibers; 

• 2824: Synthetic Organic Fibers, Except Cellulose; 

• 2865: Cyclic Crudes and Intermediates, and Organic Dyes and Pigments; 

• 2869: Industrial Organic Chemicals, Not Elsewhere Classified (NEC); 

• 2842: Specialty Cleaning, Polishing, and Sanitation Preparations; 

• 2844: Perfumes, Cosmetics, and Other Toilet Preparations; 

• 2891: Adhesives and Sealants; 

• 2899: Chemicals and Chemical Preparations, NEC; and 

• 5169: Chemicals and Allied Products. 

Based on 2002 Economic Census data, there are more than 60,000 facilities within this industry, 

of which approximately 500 facilities with NPDES permits to discharge wastewater, and 

classified as either major or minor dischargers, report to PCS. (EPA, 2007) 

EPA’s Office of Water conducted a detailed survey of the industry in 1987, and received facilityspecific data from 940 OCPSF plants. Based on 1987 data, the average flow rate for direct 
Memorandum 

10 August 2008 

Page 10 

dischargers was 1.31 million gallons per day (MGD), and for indirect dischargers was 0.25 

MGD. Table 4 illustrates the typical raw (prior to treatment) BOD and COD concentrations of 

wastewater at direct and indirect dischargers. In addition, EPA collected information on the type 

of onsite treatment conducted at OCPSF facilities. Table 5 summarizes the treatment 

information gathered. From this, it is clear that a very small percentage (1.3%) of facilities 

operated anaerobic treatment systems. In addition, no plants were identified at that time as 

operating nitrification/denitrification systems. 

Table 4. Raw Pollutant Concentrations in Wastewater Generated by OCPSF Facilities 

 Source: EPA, 1987 

Raw Pollutant Concentrations (1987)

Pollutant Direct Dischargers (mg/L) Indirect Dischargers (mg/L)

BOD5 1,088 1,784 

COD 2,908 4,571 

Table 5. Secondary Treatment Systems Reported by OCPSF Facilities 

Secondary Treatment Technology Percent of Facilities 

Reporting1

Activated Sludge Treatment (e.g., activated sludge, oxidation ditch, pure oxygen 

activated sludge) 

16.3 

Aerated Lagoon 9.5 

Aerobic Lagoon 2.6 

Anaerobic Lagoon 1.3 

Trickling Filters 1.3 

Rotating Biological Contactors 0.8 

Other 21.4 

Source: EPA, 1987 (Table VII-16) 1

Percent of operations does not add to 100% because some facilities did not report having secondary treatment, and 

some facilities reported having more than one type of secondary treatment.

Because the information collected by the Office of Water was dated, ERG accessed more recent 

data on treatment technologies reported in EPA’s Toxic Release Inventory (TRI) by OCPSF 

facilities. Table 6 presents the number of facilities that reported using particular wastewater 

treatment processes in 2000. Unfortunately, facilities only reported a general category of 

biological treatment, and not the specific type of treatment in place. However, it would be very 

unusual for a facility to move from aerobic biological treatment to anaerobic biological 

treatment. Therefore, ERG believes the 1987 data represents a maximum percent of operations 

with anaerobic treatment, and therefore is not a likely industry category for significant methane 

emissions. On the other hand, it is unclear whether this industry would have significant nitrous 

oxide emissions. Although virtually no facilities reported using nitrification/denitrification 

systems in 1987, there has been increasing interest in nitrogen discharges in the U.S. since that 

time. It is likely there has been an increase in the use of technologies to control such discharges 

from this industry. More research is needed to determine what type of nitrogen reduction 
Memorandum 

10 August 2008 

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technologies are in place, and to determine what level of nitrous oxide emissions may be likely 

from such systems. 

Table 6. Type of Wastewater Treatment Processes Reported to TRI by OCPSF Facilities 

Number of Facilities Reporting Use

Wastewater Treatment Process Direct1

 (213 facilities) Indirect1 (176 facilities)

Biological Treatment 207 60 

Settling/Clarification 136 59 

Equalization 120 65 

Neutralization 101 90 

Filtration 75 34 

Stripping (air and steam) 50 54 

Chemical precipitation 42 31 

Adsorption 32 33 

Source: TRI, 2000 

Other Preliminary Industry Investigations

ERG conducted a cursory review of industrial treatment data for other industries discharging 

significant loads of BOD, COD, and total nitrogen. 

Chlorine and Chlorinated Hydrocarbon Manufacturing. The chlorine and chlorinated 

hydrocarbon manufacturing industry was recently identified by EPA’s Office of Water, and 

includes manufacturers of ethylene dichloride (EDC), vinyl chloride monomer (VCM), and 

polyvinyl chloride (PVC), as well as chlor-alkali operations. EPA is evaluating whether chlorine 

produced by operations other than chlor-alkali will also be included. EPA’s Office of Water is 

currently collecting wastewater treatment data from these facilities; therefore, ERG recommends 

holding on any decision to include this industry until these data are available for review 

(expected Summer 2009). 

Steam Electric Power Generation. The steam electric industry includes electric utilities that 

combust coal, natural gas, and/or oil to generate electricity for distribution in commerce. Steam 

electric operations are classified in the following SIC codes: 

• 4911 Electrical Services: Establishments engaged in the generation, transmission and/or 

distribution of electric energy for sale; and 

• 4931 Electric and Other Services Combined: Establishments primarily engaged in 

providing electric services in combination with other services, with electric services as 

the major part though less than 95 percent of the total. 

While the steam electric industry was identified as a top nitrogen and BOD discharger, it is 

unlikely that their wastewater treatment processes would emit significant amounts of CH4 and 
Memorandum 

10 August 2008 

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NOx. Steam electric facilities primarily use settling ponds for treatment. Although these ponds 

are not aerated, they contain large quantities of lime and ash, and also receive large volume 

contributions from cooling water systems. It is unlikely these ponds would emit any significant 

quantities of methane or nitrous oxide. 

Textile Mills. The textiles industry includes facilities that manufacture and process textile 

materials, such as carpets, broad woven fabrics, and knitwear. It also includes facilities using wet 

processes, such as scouring, dyeing, finishing, printing, and coating, which discharge contact 

wastewater. These facilities are classified under SIC major group 22: Textile Mill Products. 

The textiles industry generates wastewater with a wide range of flow and pollutant 

characteristics. Table 7 presents median historical values of BOD and COD in wastewater from 

different subcategories within the textiles industry. 

Table 7. Historical COD and BOD Median Values in Untreated Textile Wastewater 

Subcategory BOD 

(mg/L) 

COD 

(mg/L) 

Wool Scouring 1830 6900 

Wool Finishing 150 650 

Low Water Use Processing 120-380 180-1060 

Woven Fabric Finishing 300-405 900-1240 

Knit Fabric Finishing 205-325 765-1300 

Carpet Finishing 440 1190 

Stock & Yam Finishing 190 685 

Nonwoven Manufacturing 175 2360 

Felted Fabric Processing 205 555 

Based on data from the EPA Office of Water’s 1982 Development Document for Effluent 

Limitation Guidelines and Standards for Textile Mills, 18% of direct dischargers provide no 

wastewater treatment, 19% provide only preliminary treatment (e.g., screening, sedimentation); 

56% provide biological treatment by lagoons, biological filtration, or activated sludge; and only 

7% provide advanced treatment like membrane processes and chemical 

coagulation/precipitation. 

Facilities that indirectly discharge their wastewater to POTWs may also treat wastewater on site. 

From the 1982 data, 58% of indirect dischargers discharge without treatment, 35% have only 

preliminary treatment, 7% have biological treatment, and 0.2% have advanced treatment. The 

majority of zero discharge mills have no treatment. 

ERG recommends that this industry be reviewed further to determine the potential extent of 

methane emissions. 

Fertilizer Manufacturing. The fertilizer manufacturing industry includes facilities that produce 

phosphorus- and nitrogen-based fertilizers. Facilities subject to this category typically report 
Memorandum 

10 August 2008 

Page 13 

under SIC codes 2873: Nitrogenous Fertilizers, 2874: Phosphatic Fertilizers, and 2875: 

Fertilizers, Mixing Only. Based on 2002 Economic Census data, there are 143 facilities in the 

nitrogenous fertilizers SIC code. There are another 542 facilities in the fertilizers mixing SIC 

code. (U.S. EPA, 2006) 

The fertilizer manufacturing industry was one of the top nitrogen discharging industries. There 

are a number of subcategories that may release various forms of nitrogen in their wastewater, 

including ammonia, urea, ammonium nitrate, nitric acid, and ammonium sulfate. 

Fertilizer manufacturing plants generate from 2 to 5 gallons of wastewater per ton of product. 

Ammonia plants utilize more water compared to other fertilizer plants. Effluent wastewater from 

nitrogenous fertilizer treatment commonly contains ammonia nitrogen, nitrate and organic 

nitrogen. Common waste water treatment systems include raw water filtration and clarification, 

water softening and water deionization (EPA 1974, EPA 1975). 

Although virtually no facilities reported using biological treatment systems in the 1970s, there 

has been increasing interest in nitrogen discharges in the U.S. since that time. It is likely there 

has been an increase in the use of technologies to control such discharges from this industry. 

More research is needed to determine what type of nitrogen reduction technologies are in place, 

and to determine what level of nitrous oxide emissions may be likely from such systems. 

ERG recommends that this industry be reviewed further to determine the potential extent of 

nitrous oxide emissions. 

Canned and Preserved Seafood Processing. ERG was only able to perform a very cursory 

review of this category. Within the canned and preserved seafood processing category 

wastewater characteristics vary widely. Even within one section of the category, salmon canning, 

production varies from <1 ton to 5 tons per hour, BOD5 ranges from 500 to 4,300 mg/L, COD 

ranges from 1,000 to 7,500 mg/L, and wastewater flow ranges from <1 to 22 liters per second. 

Frequently, wastewater from seafood processing plants is returned to the ocean, and sometimes 

screens are used to remove solids that are then landfilled. Other plants may discharge their 

wastewater to POTWs for treatment. Anywhere from 20-100% of plants directly discharge their 

wastewater (EPA 1975). ERG is still researching the types of treatment systems that may be in 

use by this industry. 

VI REFERENCES

U.S. Census, 2002. U.S. Economic Census. Available online at: 

http://www.census.gov/econ/census02. 

U.S. EPA. 2007. Technical Support Document for the Preliminary 2008 Effluent Guidelines 

Program Plan. EPA-821-R-07-007. United States Environmental Protection Agency, Office of 

Water, Washington, D.C., October. 
Memorandum 

10 August 2008 

Page 14 

U.S. EPA. 2006. Technical Support Document for the 2006 Effluent Guidelines Program Plan. 

EPA-821-R-06-018. United States Environmental Protection Agency, Office of Water, 

Washington, D.C. December. 

U.S. EPA. 1993. Development Document for the Proposed Effluent Limitations Guidelines and 

Standards for the Pulp, Paper and Paperboard Point Source Category. EPA-821-R-93-019. 

United States Environmental Protection Agency, Office of Water, Washington, D.C., October. 

U.S. EPA. 1987. Development Document for Effluent Limitations Guidelines and Standards for 

the Organic Chemicals, Plastics, and Synthetic Fibers Point Source Category. EPA-440-1-87-

009. United States Environmental Protection Agency, Office of Water, Washington, D.C. 

October. 

U.S. EPA. 1975. Economic Analysis of Interim Final Effluent Guidelines Seafood Processing 

Industry. United States Environmental Protection Agency, Office of Planning and Evaluation, 

Washington, D.C., February. 

U.S. EPA. 1975. Development Document for Interim Final Effluent Guidelines and Proposed 

New Source Performance Standards for the Fish Meal, Salmon, Bottom Fish, Sardine, Herring, 

Clam, Oyster, Scallop and Abalone Segment of the Canned and Preserved Seafood Processing 

Point Source Category. United States Environmental Protection Agency, Office of Water and 

Hazardous Materials, Washington, D.C., January. 

U.S. EPA. 1975. Development Document for Effluent Limitations Guidelines and New Source 

Performance Standards for the Formulated Fertilizer Chemicals Section of the Fertilizer 

Manufacturing Point Source Category. United States Environmental Protection Agency, Office 

of Water and Hazardous Materials, Washington, D.C., January. 

U.S. EPA. 1975. Development Document for Interim Final and Proposed Effluent Limitations 

Guidelines and New Source Performance Standards for the Fruits, Vegetables, and Specialties 

Segment of the Canned and Preserved Fruits and Vegetables Point Source Category. United 

States Environmental Protection Agency, Office of Water. EPA-440/1-75-046, Washington, 

D.C., October. 

U.S. EPA. 1974. Development Document for Effluent Limitations Guidelines and New Source 

Performance Standards for the Basic Fertilizer Chemicals Section of the Fertilizer 

Manufacturing Point Source Category. United States Environmental Protection Agency, Office 

of Air and Water Programs, Washington, D.C., March. 
Memorandum 

10 August 2008 

Page 15 

Attachment 1 

Ranking of BOD Discharges by Industry (2004) 

Industrial Point Source Category 

Number of Major 

Dischargers 

Reporting for BOD5 

Total Category 

Load % Total 

Organic chemicals, plastics and synthetic fibers 193 1,415,153,620 56.67 

Chlorine and chlorinated hydrocarbons 27 662,227,060 26.52 

Pulp, paper and paperboard 208 242,941,593 9.73 

Canned and preserved seafood processing 5 51,815,923 2.08 

Steam electric power generating 142 51,520,861 2.06 

Dairy products processing 4 19,443,232 0.78 

Miscellaneous Foods and Beverages 9 14,991,126 0.60 

Lumber & Wood Products 1 7,014,048 0.28 

Petroleum refining 97 6,659,440 0.27 

Sugar processing 18 4,067,733 0.16 

Meat and Poultry Products 41 3,133,954 0.13 

Grain mills 11 2,411,731 0.097 

Textile mills 62 2,163,290 0.087 

Iron and steel manufacturing 30 1,912,757 0.077 

Timber products processing 8 1,539,141 0.062 

National Security & International Affairs 29 1,444,580 0.058 

Pharmaceutical manufacturing 21 1,420,910 0.057 

Inorganic chemicals manufacturing 34 1,114,484 0.045 

Metal Products and Machinery 34 984,578 0.039 

Drinking Water Treatment 10 575,678 0.023 

Waste combustors 13 516,549 0.021 

Landfills 13 516,549 0.021 

Nonferrous metals manufacturing 12 429,958 0.017 

Centralized Waste Treatment 4 389,943 0.016 

Canned and preserved fruits and vegetables 

processing 11 343,293 0.014 

Rubber Manufacturing 15 340,134 0.014 

Pesticide chemicals 12 277,477 0.011 

Fertilizer manufacturing 11 241,874 0.0097 

Gum and wood chemicals manufacturing 2 219,132 0.0088 

Plastics molding and forming 6 134,295 0.0054 

Copper forming 3 112,082 0.0045 

Electroplating 8 106,763 0.0043 

Educational Services 4 98,785 0.0040 

Justice, Public Order, & Safety 8 78,311 0.0031 

Aluminum forming 3 76,579 0.0031 
Memorandum 

10 August 2008 

Page 16 

Industrial Point Source Category 

Number of Major 

Dischargers 

Reporting for BOD5 

Total Category 

Load % Total 

Electrical and electronic components 3 74,848 0.0030 

Printing & Publishing 1 69,552 0.0028 

Paving and roofing materials (tars and asphalt) 3 62,550 0.0025 

Phosphate manufacturing 1 59,281 0.0024 

Leather tanning and finishing 4 51,018 0.0020 

Metal Finishing 11 49,365 0.0020 

Explosives manufacturing 3 45,091 0.0018 

Airport Deicing 3 42,972 0.0017 

Heavy Construction, Except Building 1 21,752 0.0009 

Cement manufacturing 3 20,818 0.0008 

Tobacco Products 1 14,996 0.0006 

Ore mining and dressing 5 14,623 0.0006 

Soap and detergent manufacturing 3 14,276 0.0006 

Glass manufacturing 2 13,980 0.0006 

Metal molding and casting (foundries) 3 9,148 0.0004 

Nonferrous metals forming and metal powders 2 6,258 0.0003 

Executive, Legislative, & General 2 6,133 0.0002 

Trucking & Warehousing 4 5,158 0.0002 

Real Estate 1 4,554 0.0002 

Environmental Quality & Housing 2 4,533 0.0002 

Construction and Development 1 2,882 0.0001 

Independent and Stand Alone Labs 5 2,865 0.0001 

Food & Kindred Products 1 1,887 0.0001 

Mineral Mining and Processing 2 672 0.0000 

Hospital 2 477 0.0000 

Photographic 1 239 0.0000 

Photo Processing 1 239 0.0000 

Coal mining 2 117 0.0000 

Oil & Gas Extraction 1 21 0.0000 

Sanitary Services 1 - 0.0000 

Total 1,184 

 

2,497,017,771 

Source: EPA 2007. 
Memorandum 

10 August 2008 

Page 17 

Attachment 2 

Ranking of COD Discharges by Industry (2004) 

Industrial Point Source Category 

Number of Major 

Dischargers 

Reporting for COD 

 Total Category 

Load % Total 

Pulp, paper and paperboard 21 147,340,464 36.55 

Petroleum refining 72 134,104,025 33.26 

Textile mills 54 30,591,292 7.59 

Organic chemicals, plastics and synthetic fibers 66 25,678,477 6.37 

Miscellaneous Foods and Beverages 2 16,984,927 4.21 

Pharmaceutical manufacturing 19 10,967,257 2.72 

Waste combustors 7 5,199,026 1.29 

Landfills 7 5,199,026 1.29 

Timber products processing 2 3,501,512 0.87 

Rubber Manufacturing 13 2,907,437 0.72 

Centralized Waste Treatment 1 2,457,270 0.61 

Metal Finishing 16 2,138,798 0.53 

Sugar processing 3 2,098,166 0.52 

Chlorine and chlorinated hydrocarbons 6 1,926,622 0.48 

Fertilizer manufacturing 4 1,680,869 0.42 

National Security & International Affairs 7 1,525,098 0.38 

Inorganic chemicals manufacturing 9 1,478,835 0.37 

Steam electric power generating 21 1,435,618 0.36 

Iron and steel manufacturing 19 1,327,076 0.33 

Pesticide chemicals 7 1,028,601 0.26 

Electrical and electronic components 2 778,629 0.19 

Metal molding and casting (foundries) 3 721,490 0.18 

Explosives manufacturing 2 528,840 0.13 

Gum and wood chemicals manufacturing 1 405,105 0.10 

Printing & Publishing 1 348,919 0.09 

Plastics molding and forming 2 249,406 0.06 

Meat and Poultry Products 2 145,237 0.04 

Aluminum forming 1 123,685 0.03 

Nonferrous metals manufacturing 2 96,711 0.02 

Wholesale Trade- Durable Goods 1 74,880 0.02 

Battery manufacturing 1 61,471 0.02 

Construction and Development 1 16,860 0.00 

Wholesale Trade- Nondurable Goods 1 15,268 0.00 

Ore mining and dressing 2 13,835 0.00 

Trucking & Warehousing 3 6,730 0.00 
Memorandum 

10 August 2008 

Page 18 

Industrial Point Source Category 

Number of Major 

Dischargers 

Reporting for COD 

 Total Category 

Load % Total 

Nonferrous metals forming and metal powders 2 2,957 0.00 

Grain mills 1 1,489 0.00 

Mineral Mining and Processing 1 1,322 0.00 

Independent and Stand Alone Labs 1 960 0.00 

Copper forming 1 - - 

Airport Deicing 1 - - 

Total 388 

 

403,164,193 

Source: EPA 2007. 
Memorandum 

10 August 2008 

Page 19 

Attachment 3 

Ranking of Total Nitrogen Discharges by Industry (2004) 

Industrial Point Source Category 

# Major 

Dischargers 

 Total Nitrogen 

Load 

% of 

Total 

Organic chemicals, plastics and synthetic fibers 126 14,709,505 19.0% 

Steam electric power generation 83 12,517,688 16.2% 

Meat and Poultry Products 41 9,175,593 11.9% 

Pulp, paper and paperboard 72 9,124,065 11.8% 

Fertilizer manufacturing 19 6,166,094 8.0% 

Iron and steel manufacturing 38 4,309,891 5.6% 

Mineral Mining and Processing 15 3,150,156 4.1% 

Petroleum refining 90 3,111,534 4.0% 

Phosphate manufacturing 14 2,367,978 3.1% 

Pharmaceutical manufacturing 13 1,723,253 2.2% 

Inorganic chemicals 34 1,707,683 2.2% 

Miscellaneous Foods and Beverages 5 1,666,878 2.2% 

Nonferrous metals manufacturing 16 1,202,297 1.6% 

Metal Finishing 40 1,017,733 1.3% 

Explosives 4 879,369 1.1% 

Ferroalloy manufacturing 1 794,187 1.0% 

National Security & International Affairs 22 565,390 0.7% 

Sugar processing 11 434,486 0.6% 

Textile mills 38 377,188 0.5% 

Pesticide chemicals manufacturing 12 232,486 0.3% 

Plastic molding and forming 5 197,834 0.3% 

Nonferrous metals forming and metal powders 6 189,260 0.2% 

Drinking Water Treatment 7 158,653 0.2% 

Ore mining and dressing 10 140,918 0.2% 

Grain mills manufacturing 7 137,515 0.2% 

Fruits and vegetable processing 9 131,016 0.2% 

Vinyl Chloride and Chlor-Alkali 13 110,645 0.1% 

Timber products processing 5 108,060 0.1% 

Canned and preserved seafood 2 91,040 0.1% 

Rubber Manufacturing 9 87,898 0.1% 

Landfills 11 68,828 0.1% 

Waste combustors (commercial incinerators 

combusting hazardous waste) 11 68,828 0.1% 

Airport Deicing 2 57,547 0.1% 

Heavy Construction, Except Building 1 56,055 0.1% 

Electrical and electronic components 3 54,741 0.1% 

Electroplating 11 49,334 0.1% 

Educational Services 4 43,964 0.1% 

Tobacco Products 1 41,668 0.1% 

Centralized Waste Treaters 3 39,950 0.1% 
Memorandum 

10 August 2008 

Page 20 

Industrial Point Source Category 

# Major 

Dischargers 

 Total Nitrogen 

Load 

% of 

Total 

Justice, Public Order, & Safety 7 37,460 0.0% 

Lumber & Wood Products 1 36,187 0.0% 

Paving and roofing materials (tars and asphalt) 2 33,980 0.0% 

Metal molding and casting (foundries) 3 25,328 0.0% 

Independent and Stand Alone Labs 5 21,529 0.0% 

Executive, Legislative, & General 2 16,621 0.0% 

Dairy products processing 2 15,945 0.0% 

Gum and wood chemicals 1 13,842 0.0% 

Leather tanning and finishing 3 11,628 0.0% 

Aluminum forming 4 9,483 0.0% 

Glass manufacturing 1 7,772 0.0% 

Battery manufacturing 1 2,972 0.0% 

Hospital 2 2,593 0.0% 

Environmental Quality & Housing 1 2,099 0.0% 

Food & Kindred Products 1 1,507 0.0% 

Real Estate 1 768 0.0% 

Engineering & Management Services 1 435 0.0% 

Administration of Economic Programs 1 411 0.0% 

Trucking & Warehousing 2 318 0.0% 

Amusement & Recreation Services 1 274 0.0% 

Copper forming 1 147 0.0% 

Cement manufacturing 1 82 0.0% 

Coal mining 1 4 0.0% 

Photographic 1 3 0.0% 

Photo Processing 1 3 0.0% 

Total 77,308,597 

Source: EPA 2007.