4 The record articles

Final Commercial and Industrial Solid Waste Incineration (CISWI) Rule: Do You Know Your A, B, CCCCs, and DDDDs?

Posted: February 1st, 2013

Author: All4 Staff 

4 Rules Friday is a series of four blog posts highlighting key aspects of the final 4 Rules (i.e., Major and Area Source Boiler MACT, Nonhazardous Secondary Materials, and Commercial and Industrial Solid Waste Incineration).  Please refer to the graphic for each blog’s posting date.


In a rulemaking combined with amendments to the Non-hazardous Secondary Materials (NHSM) rule, the U.S. EPA Administrator signed final amendments to the March 21, 2011 Commercial and Industrial Solid Waste Incineration (CISWI) rule on December 20, 2012.  Unlike the Major and Area Source Boiler MACT rules (the remaining two of the infamous 4 Rules), which are promulgated pursuant to section 112 of the Clean Air Act (CAA), the CISWI rule is promulgated pursuant to sections 111 and 129 of the CAA and includes 40 CFR Part 60, Subparts CCCC (Standards of Performance for New Stationary Sources) and DDDD (Emission Guidelines and Compliance Times for Existing Sources).  Both standards (i.e., the New Source Performance Standards (NSPS) and Emission Guidelines (EG)) regulate emissions of the following nine pollutants pursuant to CAA section 129(a)(4): particulate matter (PM), sulfur dioxide (SO2), hydrochloric acid (HCl), nitrogen oxides (NOX), carbon monoxide (CO), lead (Pb), cadmium (Cd), mercury (Hg), and dioxins/furans (D/F).

The March 2011 version of the CISWI rule established four subcategories of CISWI units, including incinerators, small remote incinerators, solid and liquid/gas energy recovery units (ERUs) (i.e., boilers or process heaters that combust solid waste), and waste-burning kilns (i.e., cement kilns that combust solid waste).  The solid ERU subcategory was further subcategorized in the March 2011 version of the rule into coal- and biomass-fired units for CO, NOX, and SO2.  In the final rule, U.S. EPA has retained and expanded the solid ERU subcategorization to additionally apply to the emission limits for the remaining regulated pollutants.  This change is slightly different than what U.S. EPA had proposed in December 2011, in that the solid ERU subcategorization was not proposed to apply to the emission limits for HCl or Hg.  U.S. EPA has also further subcategorized the waste-burning kiln subcategory, although only for the CO emission limit, into long kilns and kilns with pre-heaters or pre-calciners, which is consistent with the December 2011 proposal.

Compared to the December 2011 proposed rule, the majority of the emission limits for existing sources have changed, and for the most part the final emission limits for existing sources are less stringent.  However, there are a few emission limits that are significantly different.  In particular, the proposed CO emission limit for existing biomass-fired ERUs was nearly cut in half from 490 to 260 ppmv, but was more than doubled for existing coal-fired units from 46 to 95 ppmv.  The proposed filterable PM emission limit for existing coal-fired ERUs nearly doubled from 86 to 160 mg/dscm.  The proposed CO emission limit for existing waste-burning kilns with pre-heaters/pre-calciners nearly doubled from 410 to 790 ppmv, but the proposed filterable PM and total D/F emission limits for existing waste-burning kilns were reduced from 9.2 to 4.6 mg/dscm and from 3.6 to 1.3 ng/dscm, respectively.

As proposed, the final rule allows for the use of uncorrected CO CEMS data (i.e., data that is not corrected to 7% O2) during startup and shutdown periods in calculating the CO 30-day rolling average.  Without this provision, correcting data during times when the O2 concentration nears ambient air (i.e., during startup and shutdown) could result in highly elevated CO levels that could potentially raise the 30-day rolling average emission rate above the applicable limit.  Since proposal, U.S. EPA has extended the specific startup and shutdown durations during which uncorrected CO CEMS data may be used.  For ERUs, incinerators, and small remote incinerators, the startup period has been extended from four hours to 48 hours, and the shutdown period has been extended from one hour to 24 hours.  For waste-burning kilns, the startup period now ends when continuous feed is introduced into the kiln, and the shutdown period now begins when feed to the kiln is ceased.  Additionally, U.S. EPA has extended this provision to any other regulated pollutants that are measured by a CEMS and corrected to 7% O2.

In an effort to eliminate uncertainty around the exemption for “qualifying small power production facilities” and “qualifying cogeneration facilities” burning homogeneous waste, U.S. EPA has removed the definition of homogeneous waste that was included in December 2011 proposed amendments from the final rule.  Instead, U.S. EPA has added examples of homogenous waste to the exemption language.

The final rule defines dry sorbent injection (i.e., dry scrubbers) as an additional type of control device that may be commonly utilized by CISWI units to comply with the rule, as well as its associated monitoring parameters.  U.S. EPA has also clarified that a source need not monitor activated carbon injection (ACI) rates or selective non-catalytic reduction (SNCR) parameters if CEMS are utilized to measure emission rates of NOX, Hg, or D/F, as applicable, and vice versa.  U.S. EPA has removed the requirement for large ERUs (i.e., greater than 250 MMBtu/hr) and waste-burning kilns to utilize PM CEMS for the purposes of directly complying with the PM emission limit, but rather is requiring the use of PM continuous parametric monitoring.

Although it was not clear during the final rule development whether the extended compliance date for existing CISWI units (except for small remote incinerators) proposed in December 2011 would remain in the final rule, the compliance date for existing sources, even including small remote incinerators, has in fact been extended to no later than five years following publication of the final rule in the Federal Register (likely in February 2017).  However, recall that individual enforcement agencies may require compliance earlier than that.  The Emission Guidelines and Compliance Times are intended to be implemented and enforced by state, local, and tribal agencies, which may establish their own rules that can be no less stringent (but may be more so) for existing sources within their jurisdiction.  Therefore, the compliance date for existing sources could be no later than three years after U.S. EPA approves the State Plan of the jurisdiction in which the source is located, or even earlier if the enforcing agency requires it.  The compliance date for new sources (those that commenced construction on or after June 4, 2010) has been extended to six months following publication of the final rule in the Federal Register or upon startup, whichever is later.

U.S. EPA notes that the CISWI rule is expected to affect 106 existing sources at 76 facilities, and six new sources within the next five years.  Compared to the Major and Area Source Boiler MACT rules, which, combined, are expected to affect nearly 200,000 existing sources and more than 8,500 new sources within the next three years, the CISWI rule may not appear to be a major concern for most facilities.  However, depending on the fuels or materials your boiler currently fires, or may fire in the future, your boiler may be classified as an ERU under the CISWI rule.  If you are considering the possibility of combusting, or continuing to combust, materials that could be classified as solid waste, it would be wise to become familiar with the CISWI rule and its requirements.

The pre-publication version of the final rule can be found here.


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