SOIL ATTENUATIVE CAPACITY AND TRANSPORT POTENTIAL
OF SOLID WASTE LEACHATES
Aaron A. Jennings, Research Assistant
Franklin S. Tirsch, Research Assistant
Donald Dean Adrian, Professor
Department of Civil Engineering
University of Massachusetts
Amherst, Massachusetts 01003
INTRODUCTION
The Resource Conservation and Recovery Act of 1976 (PL 94-580) was enacted to
"promote the protection of health and the environment and to conserve valuable materials and energy resources".   This legislation directed the Environmental Protection
Agency to prepare criteria for the classification of solid waste disposal facilities.   These
criteria are destined to have a profound impact on the solid waste disposal industry.
Under the criteria, disposal facilities will be classified as acceptable (posing no reasonable
probability of adverse effects on health or the environment) or as unacceptable.    New
facilities not meeting these criteria will be prohibited, and existing facilities not in compliance must be upgraded or closed.    Details of the criteria of classification have been
the object of much deliberation and have not yet been finalized.    They will, however,
probably not diverge substantially from the "proposed criteria for classification" published in the Federal Register [ 1 ].
If the criteria are promulgated using the proposed language and intent, then prevention of groundwater contamination will become a priority challenge facing the solid
waste disposal industry.    The proposed criteria utilize the concept of "endangerment"
for the protection of groundwater.    "Endangerment" is defined as the introduction of
any physical, chemical, biological, or radiological substance into groundwater in such a
concentration that (a) makes it necessary for an existing groundwater user to increase
treatment of the water, (b) makes it necessary for a future user of the groundwater to
use more extensive treatment of the water than would otherwise have been necessary,
or (c) otherwise makes the water unfit for human consumption.
Solid waste leachates will not be allowed to endanger groundwater quality.    For
aquifers containing groundwater which is currently used or is designated for future use
as a drinking water supply, or for aquifers containing less than 10,000 mg/1 total dissolved solids, a facility will have two options.    All leachate produced must either be
collected through the  use of landfill liners and be treated, recirculated, or removed, or
else leachate migration must be controlled by utilizing the site's natural hydrogeologic
conditions and soil attenuation mechanisms.   In addition, comprehensive groundwater
monitoring, a prediction of leachate migration, and an acceptable contingency plan for
corrective action will be required for as long as leachates enter the groundwater.
Prior to the release of these proposed criteria many states have attempted to protect
groundwaters by prescribing certain practices in the sanitary codes.   Massachusetts and
Rhode Island have required a minimum 4 foot depth of separation between the refuse
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