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for treatability studies if performed in accordance with requirements provided in 40 CFR
Comprehensive Environmental Response, Compensation, and Liability
Act of 1980 (CERCLA) as Amended by the Superfund Amendments and Reau-
thorization Act of 1986 (SARA). The primary purpose of CERCLA/SARA is to address
past disposal of hazardous wastes. Portions of the law that address past disposal of
hazardous wastes are not applicable to the operation of a plate and frame filter press.
Title III of SARA established a program that requires facilities, including wastewater
treatment plants, to notify state and local officials if the facility has hazardous sub-
stances in excess of specified threshold amounts (40 CFR 355 and 40 CFR 370).
Hazardous substances and hazardous chemicals that could be used in the operation of
the filter press include acids, caustics, and possibly sludge conditioners, depending
upon the chemicals selected.
State Regulations. State and local regulations and ordinances will also im-
pact the design and operation of the filter press. The EPA frequently delegates authority
to the individual states to implement portions of the CWA and RCRA. When the state
has received authority to implement an EPA program, it must promulgate regulations
that are at least as restrictive as the Federal regulations. States may also promulgate
regulations that are more restrictive than the Federal regulations.
States and local government agencies may also adopt regulations and ordi-
nances addressing building codes and safety features that must be incorporated into
the design of the filter press. These regulations may address such issues as handrails
and guards, first aid equipment, lighting, and ventilation. State and local regulatory re-
quirements will vary among the states and should be addressed during the design of the
plate and frame filter press.
TREATABILITY STUDIES. Treatability testing evaluates design parameters
and the potential effectiveness of the filter press. This testing may begin at the bench-
scale level and proceed to pilot-scale or full-scale testing. However, if pilot-scale testing
is not feasible, the design can be developed from the bench-scale data.
Types of Treatability Testing. The types of tests that can be conducted
include basic filterability tests and tests to optimize chemical conditioning.
2-6.1.1 Basic Filterability Testing. Basic filterability testing evaluates the filtering
properties of the sludge and determines the ease of separating the water phase from
the solid phase (EPA 1987, WEF 1992). Two basic parameters that can be used to
provide design information on final solids concentration are specific resistance and
capillary suction time (CST). The specific resistance testing can be used as a basic
guide in estimating the solids yield and cake solids. CST tests can also be used to
evaluate whether the sludge can be easily dewatered; however, they are primarily used
to evaluate the effectiveness of sludge conditioning.