Emissions of Montreal Protocol gases from one US landfill:

1
Emissions of Montreal Protocol gases from one US
landfill CFC, 1,1,1 trichloroethane, and
methane emissions from a 1.5 year landfill study
in Southern Massachusetts Elke Hodson1, Damien
Martin2, and Ron Prinn1 1Dept. of Earth,
Atmospheric, and Planetary Sciences MIT
Building 54-1326, Cambridge, MA
02139 2Atmospheric Chemistry Research Group,
School of Chemistry, University of Bristol,
Bristol, UK elkeh_at_mit.edu
Abstract No. EGU2007-A-07271

• Left to Right
• Landfill location
• (2) uncapped section
• (3) leachate tank engine plant
• (4) flare system
• (5) sample port with landfill pump system in
  background
• (6) gas wells in uncapped section
• (7) sampling equipment
• (8) aerial photograph of New Bedford landfill
  (taken by Tom Yeransian)

What We Found
What it Means
Goals of this Study
To determine the major processes governing
emissions from landfills of four halocarbons
restricted by the Montreal Protocol CFC 12
(CCl2F2), CFC 11 (CCl3F), CFC 113 (C2Cl3F3), and
1,1,1 trichloroethane (methyl chloroform,
CH3CCl3) and CH4. This is Part I. in a
two-part study to do the first known bottom-up
estimate of emissions of select Montreal Protocol
gases from landfills in the United States.
Note on Time Series The landfill gas was burned
using a high temperature flare until October
2005. This data is shown in orange. From
October 2005 until the end of the time series in
December 2006, the landfill gas was piped to four
engines which burned the gas to produce
electricity. The blue data depicts this data
set. All gas samples were collected before the
gas was burned. Emissions are calculated
assuming the sampled gas represents the gas which
is emitted to the atmosphere. Data sets with R2
gt 0.7 are indicated with a trend line.

• Concentrations and emissions of CFC 12, CFC 11,
  and to some degree methyl chloroform are
  controlled by the same processes in the engine
  system.
• CFC 113 is most likely not affected by
  engineering factors (flow rate, vacuum pressure,
  etc.), while methyl chloroform and CFC 11 seem
  strongly affected.
• Most of variability in halocarbon emissions is
  due to variability in concentrations.
• No correlation between any species and
  precipitation (5, 10 or 30 day average) was
  found. This Indicates that soil moisture is not
  important in explaining the variability in the
  concentrations. Correlations with other climate
  parameters will be further explored in future
  work.
• We will not be able to use CH4 as a way to
  extrapolate halocarbon measurements to calculate
  total US landfill emissions of CFC 12, 11, 113,
  and methyl chloroform.
• High correlation was found between methane
  emissions and flow rate. This indicates that CH4
  is highly dependent on engineering factors.
• The high correlation between methyl chloroform
  and CFC 11 in the less engineering controlled
  flare system (before November 2005) may be
  related to their high rates of biodegradation
  under anaerobic conditions9. This will be
  further explored in future work.

Why Landfills?
Several recent observational and inverse modeling
studies indicate ongoing emissions in the United
States and Europe of the four compounds indicated
above1-5. Besides the impact halocarbons have on
the ozone hole, the 2000 combined emissions of
CFCs, HFCs, and HCFCs had an equivalent global
warming potential of 2.5 billion metric tons of
CO26. Little research has gone into determining
exactly where these emissions are coming from.
One hypothesis is that banks, the halocarbons
currently in used and discarded equipment and
foams such as landfills, are the source of these
emissions. Part I. of the MIT study is a monthly
measurement campaign from August 2005-December
2006 at one landfill in Southern Massachusetts to
try to quantify seasonal variability. These
measurements will be combined with Part II.,
measurements taken in 2004 and 2006 at 11 US and
British landfills, to do the bottom-up estimation.
What We Did
Green dots outliers labeled on time series plots
no Jan 06
no Jan 06

• See also photos along top
• Landfill contains active gas collection system
  which pumps out gas through an underground piping
  system
• Capture efficiency of all landfill gas is gt 95
• Monthly samples from August 2005-December 2006
• Samples collected in pairs or triplicate in
  stainless steel electropolished flasks
• Each data point is the average of at least two
  consistent flask samples
• Each flask was analyzed in triplicate on an
  Agilent 6890N GC-ECD/FID and bracketed by
  standard runs.
• Error on precision is lt 2 for all compounds

1 Hurst, D. F., et al., Journal Of Geophysical
Research-Atmospheres Art No. D15302 Aug 4 2006,
111, (D15). 2 Barnes, D. H., et al., Journal of
Geophysical Research-Atmospheres Mar 26 2003,
108, (D6). 3 Li, J. L., et al., Journal Of
Geophysical Research-Atmospheres Art. No. D14308
Jul 30 2005, 110, (D14). 4 Gros, V., et al.,
Atmospheric Chemistry and Physics 2003, 3,
1223-1235. 5 Reimann, S., et al., Nature 2005,
433, (7025), 506-508. 6 Hileman, B., CEN May 2,
2005, pp 28-29. 7 Simmonds, P., et al., BioCycle
2006, 47, (4), 26-43. 8 Landfill Methane Outreach
Program http//www.epa.gov/lmop/proj/index.htm 9
Scheutz, C. Kjeldsen, P., Environmental Science
Technology 2003, 37, (22), 5143-5149.
HOW REPRESENTATIVE IS NEW BEDFORD LANDFILL? 64
municipal solid waste (MSW) is landfilled in
US7 25 US MSW landfills convert landfill
methane to electricity7,8 many more have active
gas collection systems combined with flares