Environmental Health News

What's Working

  • Garden Mosaics projects promote science education while connecting young and old people as they work together in local gardens.
  • Hope Meadows is a planned inter-generational community containing foster and adoptive parents, children, and senior citizens
  • In August 2002, the Los Angeles Unified School District (LAUSD) Board voted to ban soft drinks from all of the district’s schools

#71 - Decade-Old Study Revealed The Polluting Effects Of Landfills, 03-Apr-1988

A careful study of 50 landfills in 1977 concluded that 43 out of 50
(86%) had contaminated underground water supplies beyond the boundaries
of the landfill. At the other 7 sites, off-site contamination was
measured but could not be attributed to the landfills by the strict
criteria used in the study. In other words, the study of 50 landfills
found groundwater pollution at all 50 sites, but the contamination
could be definitely traced to the landfills in only 43 cases (86%).

The study was conducted by Geraghty & Miller of Port Washington, NY,
one of the nation's leading hydrology consulting firms, under contract
to EPA (U.S. Environmental Protection Agency). They looked at 122 sites
in 15 states and finally selected 50 sites in 11 states for careful
evaluation. They studied 7 in Wisconsin, 6 in Illinois, 5 in Indiana, 5
in Michigan, 2 in Pennsylvania, 5 in New York, 9 in New Jersey, 3 in
Connecticut, 5 in Massachusetts, 2 in New Hampshire, and 1 in Florida.

Criteria for selecting sites were strict: no site was selected if it
was already known to be contaminated or if there were reports of bad
taste or bad odors from drinking water near the site already; sites
were selected to include various geologic settings (various rock and
soil types) and various climatic conditions; sites were selected to
include different kinds of dumping (landfills and lagoons), and
different kinds of wastes. Some of the wastes would be termed
"hazardous" today, but many of the wastes involved were not "hazardous"
by today's legal definitions and are still allowed in municipal
landfills today. Sites had to be at least 3 years old.

The criteria for determining whether a site was contaminating
groundwater were strict. (1) Contaminants had to be measured in
groundwater beyond the perimeter of the site; (2) the concentration of
contaminants downstream of the site had to be greater than the
concentration of the same contaminants measured in an uncontaminated
background well; (3) all wells used had to be tapping the same aquifer;
(4) geologic interpretation of the data by hydrologists had to convince
them that the landfills was the source of the contamination.

In 43 out of 50 cases, the landfill was confirmed as the source of
contamination. In four other cases, contamination was confirmed, but
the area of contamination was so great that sources besides the
landfill were also suspected; at three more sites, contamination was
found but data could not be gathered from uncontaminated background
wells. So contamination was confirmed at all 50 sites, but in 7 cases,
the project's criteria could not be met for deciding that the landfill
was the culprit.

The term "landfill" was used to mean a dumping ground that accepted
garbage, demolition debris, municipal and industrial solid wastes,
sludges or liquids. The investigation "concentrated on those landfills
with a major component of industrial waste."

Some of the landfills had liners, others did not. Since publishing this
study, the EPA has published its opinion several times, that all
landfill liners will eventually leak. (See HWN #37.) Thus this study
provides important evidence that all landfills, lined or not, all
eventually contaminate groundwater. Lined landfills will contaminate
groundwater more slowly than unlined landfills, but the long-term
effects will be the same: someone's groundwater will become
contaminated whenever municipal solid waste or industrial waste or
legally hazardous wastes are placed in the ground.

The study makes some interesting points worth remembering about
landfills: "The intermixing of inorganic and organic wastes, wastes of
high and low pH, and wastes having different physical properties in a
common disposal area, may lead to influences on the environment not
anticipated from any single waste material." (pg. 7) This is important
because landfill liners are selected to be compatible with the wastes
that will be placed in a landfill. However, as this statement says, the
mixing of wastes in a landfill will produced unanticipated chemical
combinations with unpredictable results. A landfill liner selected to
withstand attack from chemicals X, Y and Z may not withstand attack
from chemicals X and Z in combination, or Y and Z in combination. The
more chemicals involved, the greater the number of possible
combinations, the more complex the interactions will be, and the less
predictable the results become.

The study makes another valuable point: "The wastes that are deposited
continue to weather and leach for years." (pg. 8) The chemical
interactions within a landfill do not cease when the dumping stops. In
the case of inorganic materials (arsenic, lead, chromium and so forth)
the duration of the hazard is essentially infinite--toxic metals will
never change into anything besides toxic metals. (The Geraghty & Miller
study found toxic heavy metals at 49 of the 50 sites and found they
contaminated groundwater off-site at 40 of the 50 sites.)

When anyone proposes a new landfill and says that liners are being
selected to prevent contamination of the environment, you should ask,
(a) How can they possibly predict all the possible combinations of
chemicals that will be created inside the landfill, producing new
combinations of chemicals that will attack the liners?; and (b) What is
the expected duration of the hazard inside the landfill vs. the
expected duration of the liners that have been selected?

If the proponents of a landfill project are honest, these questions
will force them to admit that they are not able to predict the
chemicals that will come in contact with the liner (especially since
the chemicals used by industry change from year to year, and an average
of 1000 new chemicals go into commercial use each year); and they will
be forced to admit that the duration of the hazard (in the case of
metals at least) is very great (thousands of years or longer) whereas
the expected lifetime of any human-created material (including packed
clay liners and all FMLs [flexible membrane liners]) is much shorter
than the expected hazard. Leakage is inevitable.

Common sense and available data combine to force a single conclusion:
all landfills will eventually leak. Landfill liners may SLOW the
release of contaminants into groundwater but they cannot PREVENT it.
There is no such thing as a secure landfill.

DISPOSAL SITES [EPA/530-SW-634] first published by EPA in 1977; sill
available from National Technical Information Service [NTIS],
Springfield, VA 22161; phone (703) 487-4650; order No. PB 275103;
$44.95 plus $3.00 handling.

--Peter Montague


Descriptor terms: landfilling; studies; findings; leaks; leachate;
water; groundwater; water pollution; ny; geraghty & miller; epa; wi;
il; in; mi; pa; ny; nj; ct; ma; nh; fl; criteria; hazardous waste
industry; msw; monitoring; investigations; landfill liners; toxicity;
heavy metals; siting;

Error. Page cannot be displayed. Please contact your service provider for more details. (17)