Page 49 - Wastewater Solids Incineration Systems

18 Wastewater Solids Incineration Systems

1.0 PERMITTING AND EMISSIONS REGULATIONS

Since the early 1970s, the Clean Water Act (CWA) and the Clean Air Act (CAA) have
served as the foundation of the U.S. Environmental Protection Agency’s (U.S. EPA’s)
regulatory authority. Both programs have been amended over the years to continue
to improve the environment and define the nation’s regulatory agenda.
The CWA has resulted in tremendous improvements in the quality of the waste-
water effluent from treatment plants and in the quality of the water in receiving
waterways. The CWA Amendments of 1987 required the U.S. EPA to establish stan-
dards for use or disposal of “sewage sludge,” including incineration, and were incor-
porated into Title 40 Part 503 of the Code of Federal Regulations (40 CFR 503). The
CAA includes requirements for the combustion of wastewater treatment plant
(WWTP) residuals, which is recognized in the Part 503 regulations. Wastewater treat-
ment plants that are thermally treating residuals must meet the requirements of both
the CWA and CAA.
The CAA has greatly reduced emissions to the atmosphere and improved air
quality in urban areas. The CAA not only established emission limits for individual
emission units, it also considered other sources at the facility and the attainment
status of the ambient air in the region in which the facility is located. Construction of
a new facility cannot commence until all of these considerations have been
addressed. With the passage of the CAA Amendments of 1990, many new programs
were implemented, including emission limits for hazardous air pollutants from spe-
cific source groups and the Title V Operating Permit program to document and track
emissions on a continuing basis for the entire plant.
Thermal treatment processes for WWTP residuals must be reviewed before con-
struction of the facility or completion of planned modifications. The CAA requires
that a facility undergo a two-step air permit review process and receive approval
from the reviewing agency (U.S. EPA regional office or delegated state or local regu-
lated authority) before construction can begin. The attainment status of the facility
site, local meteorology or terrain features, and state regulatory requirements will
affect the specific emission limits that may apply to a facility. Once the facility is com-
pleted, a performance test is conducted to demonstrate that the pre-construction
limits have been met. An operating permit application then needs to be submitted
and approval issued for the facility to continue operating. Careful consideration to
the air permitting requirements for a thermal treatment system must be made at the
early planning and design phases of a project.