The NAEMS Project

The National Air Emissions Monitoring Study (NAEMS)

Livestock air emissions are subject to permitting requirements under the Clean Air Act as well as reporting requirements under the Emergency Planning and Community Right-to-Know Act (EPCRA) and the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) if their emissions reach specified thresholds. In order to ensure compliance with these requirements and create a national methodology for estimating livestock air emissions, EPA developed the NAEMS under the Air Compliance Agreement with 2,600 participating AFOs. The NAEMS began in June 2007 to measure air emissions at 24 sites (including all major types of swine, dairy and laying hen facilities) in nine states over a two-year period. Measurements of air emissions included: PM, NH3, H2S and VOC. Within 18 months of the study’s completion, EPA was to develop and publish air emission estimating methodologies for types of facilities included in this study.

Results of the 2-yr period NAEMS emission data (from animal houses, g/d-head)
Species
NH3
H2S
PM10
VOC
Sow gestation
6.5-29.4
0.3-8.5
0.28-0.48
1.8-7.2
Farrow
1.9-10.0
3.8-7.6
1.17-1.67
10.4-12.1
Finishing swine
6.7-8.4
0.23-0.85
0.18-0.29
0.6-5.5
Dairy
5.0-56.5
0.9-4.9
0-10.3
12-197
Hens - High rise
0.63-1.12
0.001
0.016-0.038
0.03-0.34
Hens - Manure belt
0.28
0.002
0.008-0.025
0.03-0.04
Broilers
0.47-0.54
0.003
0.044-0.045
0.10-0.13

 

Implications

The raw data collected in the NAEMS, along with data from published scientific journals suggest that there is considerable variation among types of farms (swine, dairy, laying hen, and broiler chickens) and even within a specific type of farm. The EPCRA and the CERCLA required reporting of NH3 and H2S emissions exceeding 100 lb/day. Based on currently available data (house emissions only), the farm sizes that may trigger the need for a farm to report under EPCRA were estimated as following.

  • Sows: 1500-7000 head
  • Finishing swine: 5400-6800 head
  • Dairy: 800-9100 head
  • Beef: 200-600 head
  • Layers: 41000-160000 head
  • Broilers: 85000-96000 head
  • Turkeys: around 46000 head