Hot Mix Asphalt Facilities: New Source Performance Standards (NSPS)
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On June 11, 1973 (38 FR 15406), pursuant to section 111 of the Clean Air Act, as amended, the Administrator proposed standards of performance for new and modified stationary sources within seven categories of stationary sources:
- Asphalt concrete plants,
- petroleum refineries,
- storage vessels for petroleum liquids,
- secondary lead smelters,
- secondary brass and bronze ingot production plants,
- iron and steel plants, and
- sewage treatment plants.
In the same publication, the Administrator also proposed amendments to subpart A, General Provisions, and to the Appendix, Test Methods, of 40 CFR Part 60.
A Hot Mix Asphalt (HMA) plant can be constructed as a permanent plant, a skid-mounted (easily relocated) plant, or a portable plant. All plants can have Reclaimed Asphalt Pavement (RAP) processing capabilities. Virtually all plants being manufactured today have RAP processing capability. Most plants have the capability to use either gaseous fuels (natural gas) or fuel oil.
However, based upon Department of Energy and limited State inventory information, between 70 and 90 percent of the HMA is produced using natural gas as the fuel to dry and heat the aggregate. HMA paving materials are a mixture of size-graded, high quality aggregate which can include RAP and liquid asphalt cement, which is heated and mixed in measured quantities to produce HMA. Aggregate and RAP (if used) constitute over 92 percent by weight of the total mixture.
Aside from the amount and grade of asphalt cement used, mix characteristics are determined by the relative amounts and types of aggregate and RAP used. A certain percentage of fine aggregate (less than 74 micrometers [μm] in physical diameter) is required for the production of good quality HMA. Hot mix asphalt paving materials can be manufactured by:
- batch mix plants,
- continuous mix (mix outside dryer drum) plants,
- parallel flow drum mix plants, and
- counterflow drum mix plants.
This order of listing generally reflects the chronological order of development and use within the HMA industry.
04/10/1986 – Final Rule; correction
07/25/1977 - Final Rule
10/06/1975 – Final Rule; Revisions to Performance Testing Methods
03/08/1974 – Final Rule
06/11/1973 – Proposed Standards
5 Source Categories - Hot Mix Asphalt Plants (Proposed Rule) - This page includes a calculation spreadsheet for emissions
Applicability Determination Index (ADI). The ADI is maintained by EPA's Office of Enforcement and Compliance Assurance (OECA) and provides a data base of memoranda dealing with applicability issues. The database is searchable by Subpart.