Environmental Engineering Reference
In-Depth Information
types of wastes remain after the treatment is complete are exempt from
regulation.
Dredge materials exclusions. Dredge materials subject to the permitting
requirements of Section 404 of the Federal Water Pollution Control Act
(FWPCA) of section 103 of the Marine Protection, Research, and Sanc-
tuaries Act (MPRSA) of 1972 will not be considered as hazardous wastes.
3.2.3.2
Special Regulatory Conventions for Hazardous Waste
Under certain circumstances, the hazardous waste may be mixed with other non-
hazardous waste; generate residues during treatment, storage, and disposal processes;
and be spilled on soils or constructions. The Special Regulatory Conventions, includ-
ing mixture rule, derived-from rule, and contained-in policy are proposed by RCRA
to deal with such situations.
(a) Mixture Rule
Hazardous wastes sometimes become mixed with other nonhazardous wastes when
generated. The mixture rule is intended to ensure these mixtures are regulated in a
manner that minimizes threats to human health and the environment. Regardless of
what percentage of the waste mixture is composed of listed hazardous wastes, the
mixture bears the same waste code and regulatory status as the original listed
component of the mixture, unless the generator obtains a delisting. This is intended
to prevent any generators from evading RCRA requirements simply by mixing or
diluting the listed wastes with nonhazardous solid waste. Characteristic wastes are
hazardous because they possess one of four unique and measurable properties.
According to the mixture rule, a mixture involving characteristic waste will no longer
be regulated as hazardous if the characteristic waste does not exhibit one of the four
dangerous properties.
The mixture rule also contains some exceptions, or exclusions, such as a com-
paratively small quantity of listed hazardous waste routed to large-volume waste-
water treatment systems.
(b) Derived-From Rule
The derived-from rule is applied to residues generated from hazardous waste treat-
ment, storage, and disposal processes that may contain high concentrations of both
listed and characteristic hazardous waste. The rule states that any material derived
from a listed waste or characteristic waste (only if it exhibits a hazardous charac-
teristic) will also be considered as corresponding hazardous waste. Thus, even if a
hazardous waste is burned out, the ash will still bear the same regulations as the
original hazardous waste.
(c) Contained-In Policy
The contained-in policy is created to handle the condition when some listed or charac-
teristic wastes spill onto the environmental media such as soil and groundwater, and
debris such as dismantled construction materials and discarded personal protective
equipment. According to this policy, the environmental media and debris will be regu-
lated as hazardous waste when contaminated by a RCRA listed or characteristic waste.
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