Volume 6, Number 4
A Gossman Consulting, Inc. Publication
November 2001

HWC MACT Changes by Court Ruling


David Constans

As everyone knows, the US Court of Appeals for the DC Circuit issued a final ruling on July 24, 2001 regarding the HWC MACT regulation.  Many are familiar with the gist of the ruling; that an interim standard will be put in place and that a new final rule will be written and promulgated by June 14, 2005.  This Tech Notes will present the changes applicable for cement kilns from this court ruling.   Warning – The Interim Standards Rule and Final Standards Rule proposed by the EPA and submitted to the Court have not been released for publication. They could be rejected completely or be changed.

Interim Standards Rule

The EPA will promulgate on or before February 14, 2002 a set of interim standards.  These standards will be the existing HWC MACT rule with certain court-mandated changes.   These changes Fall into three areas: 1.  Changes to emissions limits that must be met; 2.  Revisions to requirements for performance testing compliance, applicable only to this interim emissions standards period;  3.  Changes to monitoring and compliance provisions.

In brief, the emissions limitation changes in the proposed interim standards for cement kilns are only applicable for mercury and the semi volatile metals (lead plus cadmium).  It also appears that the standard allowing the use of a hazardous waste mercury MTEC feed rate limit is to be a substitute to the requirement of 63.1204(a)(3) (Emission limits for existing kilns) and 63.1204(b)(2) (Emissions limits for new kilns) as opposed to a change in values in 63.1206(b)(10) (Alternative standards for existing or new cement kilns).  This is important because there are requirements in 63.1206(b)(10) which could be quite onerous, such as petitioning for this alternative standard and providing extensive justification and data.

Emissions Limits Changes

The table below presents the current existing HWC MACT emissions limits and the proposed interim standards limits.

Compliance Testing and Testing Interval Changes

Section 63.1207, Performance Testing Requirements, is amended for the “Interim Standards Rules” period to; 1) allow data-in-lieu of, regardless of the age of the collected data, to serve as documentation of compliance with the interim standards provided the data meets QA requirements and is sufficient to establish operating parameter limits.  Previously data-in-lieu of could be not be taken from a test sequence initiated before March 30, 1998; 2) no performance tests after the initial performance test is required.  The HWC MACT regulation required a 61 month or less interval between comprehensive performance tests; 3) the confirmatory test is eliminated for the interim standards rules period.  The HWC MACT regulation had called for a 31 month or less interval between a comprehensive performance test and a confirmatory performance test.

Changes to Monitoring or Compliance Provisions

A totally revised Start-up, Shutdown and Malfunction Plan requirement is being proposed as a part of the interim standards rule. 

It is also proposed to delete the minimum power requirements for ”ionic wet scrubbers” (these are not the ESP’s commonly in use at cement kilns)

and to delete the carbon bed age confirmatory emissions test.  Since there are no carbon beds being utilized at cement kilns this will be of no interest to cement manufacturing facilities.

Final Amendments Rule

The EPA has proposed a list of amendments to the HWC MACT rule in conformance to the court ruling.  These are to be promulgated on or before February 14, 2002.  Unlike the interim standards above these rules actually amend the HWC MACT rule.  Eleven of the 13 proposed amendments were revisions made to the 1999 HWC MACT rule in the direct final rule published on July 3, 2001.  These revisions are the result of petitions and data provided by the regulated community requesting clarification or modif-ication of specific implementation, monitoring or reporting requirements.  None of these proposed amendments affect the emission standards.  The remaining 2 proposed amendments are in the same vein, modifications of implementation or monitoring provisions.

Virtually all of these proposed amendments are old news.  Their inclusion in the Final Amendments Rule is a way for the EPA to incorporate these modifications into the HWC MACT regulation.   If you wish to have additional information about these proposed amendments call GCI at 847-683-4188 and one of our consultants will be happy to discuss your concerns.







Dioxin Emission

 <0.2 TEQ ng/dscm @7%O2

or >0.2 but < 0.4 TEQ ng/dscm @7%O2 with APCD < 400°F

Dioxin Emissions

No Change


Mercury Emissions Limits

Existing Kilns     120 ųg/dscm @7%O2

New Kilns           56 ųg/dscm @7% O2

(Use of MTEC feedrate limits required petition and extensive data support.)

Mercury Emissions Limits

Existing Kiln    No Change

New Kilns        120 ųg/dscm @ 7% O2

Allows use of a MTEC feedrate limit calculated not to exceed 120 mg/dscm @ 7% O2 without petition or data support.

Semi Volatile Metals (Pb & Cd)

Existing Kiln     240 ųg/dscm @ 7% O2

New Kiln          180 ųug/dscm @ 7% O2

Semi Volatile Metals (Pb & Cd)

Existing Kiln     330 ųg/dscm @ 7% O2

New Kiln          No Change


Low Volatile Metals (As, Be & Cr)

Existing Kiln      56 ųg/dscm @ 7% O2

New Kiln           54 ųg/dscm @ 7% O2


Low Volatile Metals (As, Be & Cr)

Existing Kiln      No Change

New Kiln           No Change

Particulate Emissions

< 0.15 kg/Mg dry feed and > 20% Opacity

Particulate Emissions

No Change

THC and CO

Facility selects appropriate requirements from options offered in regulation

THC and CO

No Change


HCL and Chlorine

130 ppmv dry @ 7% O2


HCL and Chlorine

No Change