ARCADIS G&M, Inc. 

4915 Prospectus Drive 

Suite F 

Durham 

North Carolina 27713 

Tel 919 544 4535 

Fax 919 544 5690

MEMO 

To: 

Ms. Elizabeth Scheehle, EPA

Copies: 

Ms. Diana Pape, ICF 

Ms. Shannon Prendergast, Tetratech 

From:

Michiel Doorn 

 

Date: ARCADIS Project No.: 

21 June 2010 RN009201.0001 

Subject:

New Meat & Poultry Estimates 

ARCADIS obtained from Tetratech and EPA/OW a spreadsheet with data for 41 meat or poultry 

plants. Typically, three distinct processes could be distinguished: slaughtering, further processing 

and rendering. Wastewater from these three processes is treated in an anaerobic lagoon. Two 

plants used different treatment technologies; an anaerobic digester and an anaerobic rotating 

biological contactor. These plants were not excluded, because both processes are likely to produce 

methane. One plant that appeared to be only for rendering was excluded. There are three meat 

plants that receive some poultry products for processing. However, the poultry share is negligible 

(<1.6%) compared to the meat share, so it was ignored. Pertinent data include: 

 Separate flows from slaughtering, further processing and rendering going into the 

anaerobic lagoon. (gal/year). These were added together. 

 Average BOD concentration of the influent into the anaerobic lagoon (mg/liter) 

 Quantity of meat or poultry slaughtered (live weight killed, lbs/year). 

Production data (lbs/year) for further processing and rendering were also available, however these 

were not used, because adding them to the slaughter production, would constitute double 

counting. Several plants did receive external product for further processing and rendering in 

addition to their own contributions, however, it could not be determined to what degree and now 

adjustments were made. The reasoning is as follows. It was assumed that the 40 plants are a 

representative sample of US packing plants. If the plant exports further processing and or 

rendering products, the wastewater associated with these activities would be processed at a 

receiving plant. The original plant would have less wastewater loading, while the receiving plant 

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would have more wastewater loading. However, the average wastewater loading for the two 

plants would not be affected. 

The plants in the EPA/OW sheet are separated in poultry and meat plants. Activity data available 

from the Census also allow for this segregation, so this constitutes an improvement in the quality 

of the activity data. 

The existing GPG methodology to estimate CH4 emissions from meat and poultry wastewater 

requires the following input: 

 emission factor ( 0.25 g CH4/g COD); 

 production (tons/year, carcass weight) from Census; 

 outflow (13 m3

/ton with a range of 8 – 18); 

 average organics loading (4.1 COD/m3

 with a range of 2 – 7); and 

 a factor (TA) to express which part of BOD is treated anaerobically (0.77). 

The spreadsheet from EPA/OW includes somewhat different data that may lead to more accurate 

factors. The organics loading is presented in BOD instead of COD. Thus the emission factor will 

have to be expressed accordingly (i.e., 0.6 g CH4/g BOD versus 0.25 g CH4/g COD). Another 

difference is that both BOD concentration and (out)flow are determined for the actual lagoon 

influent and not the wastewater outflow. This eliminates having to account for the influences of 

upstream wastewater treatment technologies. The TA factor used in the GPG methodology was 

0.77. Because the measuring point is now at the actual lagoon inlet, this factor becomes 1.00. 

Production data submitted by Tetratech and EPA/OW are expressed in live weight killed (LWK), 

while the Inventory uses USDA/Census data in “carcass weight.” Carcass weight does not include 

head, hide and internal organs and thus would be lower than LWK. Conversion factors to convert 

LWK to “dressed weight” were provided by Tetratech. (Savell and Smith, 2000; Mead, 1989.1

) It 

was judged by Tetratech2

 that “dressed weight” is similar to “carcass weight”. Conversion factors 

to convert LWK to carcass weight are: 

Beef: 62.5 % 

Pork: 73 % 

Turkeys: 75 % (assumed the same for chickens) 

In 2001 production of beef and pork was 26,212 and 19,160 (poultry, 36,839) million pounds 

(carcass weight) respectively. Thus, the weighted conversion factor for beef and pork is 67 %. 

 1

 G. C. Mead. 1989. Processing of Poultry by, AFRC Institute of Food Research, Bristol Laboratory, 

Langford, Bristol, UK. 

Jeffrey W. Savell and Gary C. Smith. 2000. Meat Science, Laboratory Manual. Seventh 

Edition. 

2

 Teleconference. 

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The flow into the lagoon in gal/year was divided by the slaughter quantity (tons/year) yielding 

inflow into the anaerobic lagoon per production unit (m3

/ton). 

Statistical data on BOD concentrations and lagoon inflows are summarized in Table 1. 

 Table 1. New Factors based on EPA/OW data 

BOD concentration 

lagoon influent 

Flow into 

lagoon 

Units (g/m3) (m3/ton) 

Number of data points 4 21 

Average 1,508 16.6 

Lowest 680 2.6 

Highest 2,347 27.8 

Poultry 

Standard Deviation 721 6.7 

Number of data 14 8 

Average 2,822 7.9 

Lowest 957 3.8 

Highest 7,236 30.9 

Meat 

Standard Deviation 1,624 5.9 

New methane emissions estimates were computed using the data from Table 1 and are included in 

Table 2. Once the data have been reviewed, ARCADIS will redo the complete time-series. The 

new estimates for total meat & poultry wastewater are 0.540 Tg, compared to 0.396 Tg for the old 

estimates. This is a factor 1.36 higher. 

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TABLE 2. NEW METHANE EMISSION ESTIMATES

OLD DATA Methane GWP: 21

RED MEAT AND POULTRY 1990 2001 2002

Output (million lbs, carcass) 62,255 82,643 

Output (metric tons x 1000) 28,239 37,487 38,550 

WW Outflow (m3/ton) 13 13 13

COD (g/l) 4.1 4.1 4.1

COD produced (Gg/yr) 1,998 1,505 2,055 

TA (%) 77 77 77

Emission factor (Mg CH4/Mg COD) 0.25 0.25 0.25

Total Emissions (Tg or MMT) 0.290 0.385 0.396

Total Emissions (MMT CO2) 6.084 8.077 8.306

Total Emissions (Gg CO2) 6,084 8,077 8,306 

NEW DATA Methane GWP: 21

RED MEAT 1990 2001 2002

Output (million lbs, carcass) 62,255 45,804 

Output (metric tons x 1000) 28,239 20,777 21,358 

WW Outflow (m3/ton) 5.3 7.9 7.9

BOD (g/l) 4.1 2.8 2.8

BOD produced (Gg/yr) 460 614 472 

TA (%) 77 100 100

Emission factor (Mg CH4/Mg COD) 0.25 0.6 0.6

Total Emissions (Tg or MMT) 0.118 0.276 0.283

Total Emissions (MMT CO2) 2.481 5.791 5.953

Total Emissions (Gg CO2) 2,481 5,791 5,953 

Methane GWP: 21

POULTRY 1990 2001 2002

Output (million lbs, carcass) 62,255 36,839 

Output (metric tons x 1000) 28,239 16,710 17,178 

WW Outflow (m3/ton) 13 16.6 16.6

BOD (g/l) 4.1 1.5 1.5

BOD produced (Gg/yr) 416 1,505 428 

TA (%) 77 100 100

Emission factor (Mg CH4/Mg COD) 0.25 0.6 0.6

Total Emissions (Tg or MMT) 0.290 0.250 0.257

Total Emissions (MMT CO2) 6.084 5.243 5.389

Total Emissions (Gg CO2) 6,084 5,243 5,389 

TOTAL

Total Emissions (Tg or MMT) 0.525 0.540

Total Emissions (MMT CO2) 11.0 11.3

Total Emissions (Gg CO2) 11,033 11,342 

Note: 2002 data were not yet available and were extrapolated from 2001.