Waste Management 2011 Annual Report Download - page 133

The number of landfills we own or operate as of December 31, 2011, segregated by their estimated
operating lives (in years), based on remaining permitted and expansion airspace and projected annual disposal
volume, was as follows:
0to5 6to10 11 to 20 21 to 40 41+ Total
Owned ................................. 11 9 32 69 90 211
Operated through lease(a) .................. 5 4 4 5 7 25
Operating contracts(b) ..................... 10 6 8 5 6 35
Total landfills ............................ 26 19 44 79 103 271
(a) From an operating perspective, landfills we operate through lease agreements are similar to landfills we own
because we own the landfill’s operating permit and will operate the landfill for the entire lease term, which
in many cases is the life of the landfill. We are usually responsible for the final capping, closure and post-
closure obligations of the landfills we lease.
(b) For operating contracts, the property owner owns the permit and we operate the landfill for a contracted
term, which may be the life of the landfill. However, we are generally responsible for final capping, closure
and post-closure obligations under the operating contracts.
The following table reflects landfill capacity and airspace changes, as measured in tons of waste, for
landfills owned or operated by us during the years ended December 31, 2011 and 2010 (in millions):
December 31, 2011 December 31, 2010
Remaining
Permitted
Capacity
Expansion
Capacity
Total
Capacity
Remaining
Permitted
Capacity
Expansion
Capacity
Total
Capacity
Balance, beginning of year . . . 4,391 603 4,994 4,075 726 4,801
Acquisitions, divestitures,
newly permitted landfills
and closures ............ — — — 14 — 14
Changes in expansions
pursued(a) .............. — 101 101 — 120 120
Expansion permits
granted(b) .............. 84 (84) — 238 (238) —
Airspace consumed ........ (90) — (90) (91) — (91)
Changes in engineering
estimates and other(c) .... 100 1 101 155 (5) 150
Balance, end of year ........ 4,485 621 5,106 4,391 603 4,994
(a) Amounts reflected here relate to the combined impacts of (i) new expansions pursued; (ii) increases or
decreases in the airspace being pursued for ongoing expansion efforts; (iii) adjustments for differences
between the airspace being pursued and airspace granted and (iv) decreases due to decisions to no longer
pursue expansion permits.
(b) We received expansion permits at eight of our landfills during 2011 and 13 of our landfills during 2010,
demonstrating our continued success in working with municipalities and regulatory agencies to expand the
disposal capacity of our existing landfills.
(c) Changes in engineering estimates can result in changes to the estimated available remaining capacity of a
landfill or changes in the utilization of such landfill capacity, affecting the number of tons that can be placed
in the future. Estimates of the amount of waste that can be placed in the future are reviewed annually by our
engineers and are based on a number of factors, including standard engineering techniques and site-specific
factors such as current and projected mix of waste type; initial and projected waste density; estimated
number of years of life remaining; depth of underlying waste; anticipated access to moisture through
precipitation or recirculation of landfill leachate; and operating practices. We continually focus on
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