Page 58 - Wastewater Solids Incineration Systems

Permitting and Emissions Regulations 27

combination of these that process WWTP residuals shall not exceed 3.2 kg (7.1 lb)
of mercury per 24-hour period.
In addition to the criteria pollutants regulated by the NAAQS, there is another
set of federally regulated air pollutants known as hazardous air pollutants (HAPs).
Hazardous air pollutants are a set of 188 chemicals specifically regulated by the U.S.
EPA that are known or believed to cause human health effects in excess of levels spec-
ified by the agency.
Sources that emit more that 9 Mg/a (10 ton/yr) of an individual HAP or more
than 23 Mg/a (25 ton/yr) of multiple HAPs are considered a significant source of
HAPs. Significant sources of HAPs may be subject to the maximum achievable con-
trol technology (MACT) regulations (40 CFR 63). Subpart VVV defines MACT stan-
dards for WWTPs. However, the standards in this subpart not address solids-pro-
cessing or thermal treatment systems.
If a WWTP treats industrial wastes and is considered a part of a miscellaneous
organic chemical manufacturing process unit (MCPU), then emission control require-
ments may apply. These additional requirements are defined in 40 CFR 63 Subpart
FFFF National Emission Standards for Hazardous Air Pollutants: Miscellaneous
Organic Chemical Manufacturing.

3.3 State and Local Regulatory Requirements
Even if a thermal treatment facility is relatively small, state pre-construction permit-
ting requirements may apply. Although the review requirements may not be as strin-
gent, the same emission limits may apply. Most states require a BACT analysis to
determine the appropriate air pollution control equipment and emission limits.
Many states also have special regulations governing toxic air pollutant emis-
sions. Some state rules define a control technology assessment for toxic air emissions
(T-BACT). Other states require a dispersion modeling assessment to show toxic air
pollutant emissions are in compliance with allowable ambient levels. State air toxics
programs also may establish emission limits of some hazardous air pollutants.
Additional regulations may also apply with respect to noise and odors. Special
compliance demonstrations or pre-construction assessments of potential noise and
odor effects may be required. Applicable standards may be developed on a case-by-
case basis and include communication with the public and involvement of other
interested parties.
Visual plume emissions are regulated by opacity limits as defined in many state
regulations. Meeting these opacity limits may not prevent the formation of a yellow