Asphalt Millings Guidance Document

A. ASPHALT MILLINGS GENERAL INFORMATION

This guidance document outlines the New Jersey Department of Environmental Protection's (DEP or Department) guidance for use of asphalt millings (bituminous concrete). The guidance document is intended only as a guide to help the reader understand the need for controlled use of millings in some forms of use and does not replace any regulations in any context. Asphalt millings may be: recycled pursuant to existing regulations at N.J.A.C. 7:26A-1.4(a)1 for recycling directly into new asphalt without Department approval; reused directly for road construction in some situations without Department approval; and, used for beneficial uses pursuant to N.J.A.C. 7:26-1.7(g) with site specific Department approval as discussed below.

B. ASPHALT MILLINGS DEFINITION

The definition most commonly used for asphalt millings is the fine particles (generally from dust to less than an inch or so) of bitumen and inorganic material that are produced by the mechanical grinding of bituminous concrete surfaces.

C. WHAT ARE ASPHALT MILLINGS?

Asphalt millings contain approximately five to seven percent asphalt, which is used as a binder for the quarry materials (stone, rock, sand, silt) that make up the load-bearing portion of a bituminous concrete surface. The asphalt millings are produced by grinding a bituminous concrete-paved surface which results in the generation of fine particles of bitumen and inorganic material that made up the road surface.

D. SOURCES AND QUANTITIES OF ASPHALT MILLINGS

Sources of asphalt millings include highway departments and local contractors hired to conduct road improvements. Quantities of millings from a particular operation can vary greatly from a few tons to hundreds of thousands of tons and quality will vary dependant on the original asphalt character, age, weather and other site-specific conditions.

E. ENVIRONMENTAL AND PUBLIC HAZARDS

The bitumen binder used in asphalt paving applications contains a relatively large concentration of a family of carcinogenic compounds which can pose serious human health and environmental concerns in certain circumstances such as when asphalt material is ground into very small particles that easily blow off of or wash from the surface. These compounds, known as polycyclic aromatic hydrocarbons (PAHs) are specified as targeted pollutants by the U.S. Environmental Protection Agency (USEPA), and are present in asphalt at much higher levels than the criteria established by the DEP for general use in a loose fashion on land. Asphalt millings used alone without a paved top surface have the potential to significantly migrate from the roadway through the actions of water, wind, and physical displacement and possibly contaminate surrounding soils and/or surface water sediments. Traffic traveling on the unpaved asphalt millings would generate dust containing the compounds referenced above and the dust would be a major migration route of the millings to the surrounding environment.

F. BENEFICIAL USE OF ASPHALT MILLINGS

Several uses in of asphalt millings are fully appropriate in accordance with regulations for recycling and beneficial use and, therefore, millings may be used as follows below. The use of loose unbound asphalt millings on land and roadway surfaces without the placement of a paved top surface is not generally appropriate. Millings should not be used where runoff to surface water features would be possible in order to prevent sediment contamination. In addition, asphalt millings are not considered clean fill.

1. Millings may be taken directly to and used by road asphalt manufacturing plants for direct incorporation into asphalt (bituminous concrete), pursuant to the recycling exemption for such use at N.J.A.C. 7:26A-1.4(a)1.

2. As sub-base material directly beneath, and fully contained by, a paved road surface of either bituminous asphalt or Portland cement concrete. The use of asphalt millings as a sub-base is required to be in strict accordance with the New Jersey Department of Transportation (DOT) requirements mentioned below and other site-specific criteria as determined and approved by the DEP for use of asphalt in road construction, and shall not involve any filling of wetlands or wetland encroachment or used as general fill, and is in accordance with all local construction code/permits. Using millings by following the DOT 1996 Standard Specification for Road and Bridge Construction Subsection 202.12 concerning roadway sub-base construction and depth requirements for roadway embankments is prudent guidance for appropriate use of millings that was not recycled back into asphalt. Per Subsection 202.12, the use of excavated bituminous concrete, in accordance with that subsection, may be placed in the lower portion of Zone 3 embankments and not placed within 600 millimeters of the final sub-grade or less than one meter above the highest seasonal high groundwater table. Such use should adequately prevent the millings from entering the surface water and groundwater features in most instances.

a. This use is considered direct recycling pursuant to N.J.A.C. 7:26-1.1(a)1 and does not require authorization as a Beneficial Use Project from the Department pursuant to N.J.A.C. 7:26-1.7(g) if performed to construct or repair a needed vehicle surface that meets DOT and/or local construction requirements.

3. Asphalt millings may be used as surfacing materials if an appropriate binder is applied to keep the millings in place. Liquid asphalt (tack) may be used to bind the asphalt millings in surficial applications. This may be less expensive than applying finished asphalt or concrete to meet the sub-base requirements described above and meets the need to fully contain and bind the particles to prevent wind and water erosion.

a. This use is considered direct recycling pursuant to N.J.A.C. 7:26-1.1(a)1 and does not require authorization as a Beneficial Use Project from the Department pursuant to N.J.A.C. 7:26-1.7(g) if performed to construct or repair a needed vehicle surface that meets DOT and/or local construction requirements.

4. Asphalt millings may be used to construct, or repave, needed roadway or vehicle use areas such as parking lots if such application is performed when the material is sufficiently hot to make the asphalt pliable and adhesive, that is, if the millings contain sufficient viable asphalt (or additional asphalt "tack") to bind the millings particles on application. This application of the hot millings must be followed by immediate hot rolling to complete the integration of the milling pieces and particles into a bound surface that is similar in consistency and performance to an integral asphalt-paved surface such as a road. Rolling the surface will not only serve to permanently rebind the milling particles into the hot asphalt matrix to prevent erosion but also will ensure a flat paved surface suitable for vehicular use.

a. This use is considered direct recycling pursuant to N.J.A.C. 7:26-1.1(a)1 and does not require authorization as a Beneficial Use Project from the Department pursuant to N.J.A.C. 7:26-1.7(g) if performed to construct or repair a needed vehicle surface that meets DOT and/or local construction requirements.

5. Other uses of asphalt millings may be authorized pursuant to regulations at N.J.A.C. 7:26-1.7(g) for beneficial use of materials. Contact the Beneficial Use section of the Bureau of Resource Recovery and Technical Programs, Division of Solid and Hazardous Waste at (609) 984-6985 for more information on the authorization process for a Certificate of Authority to Operate a Beneficial Use Project for millings beneficial use applications. An application form for a Certificate of Authority to Operate a Beneficial Use Project, along with other information concerning the regulation of beneficial use of materials in New Jersey, can be found within the internet web page for beneficial use at: http://www.state.nj.us/dep/dshw/rrtp/bud.htm .

G. VEHICLE REQUIREMENTS

Note that DEP solid waste vehicle registration pursuant to N.J.A.C. 7:26-1 et seq. for trucks hauling asphalt millings is not required for the transport of millings for uses meeting the conditions of Section F 1 through 4 above or DEP-approved recycling or beneficial uses. However, DEP solid waste vehicle registration is required for vehicles if millings are being disposed of as solid waste pursuant to N.J.A.C. 7:26-1 et seq. in or out of State.

H. COMPLIANCE WITH OTHER LAWS AND REQUIREMENTS

Any selected use of asphalt millings must be consistent with other applicable or relevant Federal, State or local laws or regulations. If a proposed use does not comply with other applicable laws, the use would not be approved by the Department and thus would be considered to be landfilling with illegal materials and creating an illegal landfill. Those responsible for implementing any proposed use for asphalt millings must identify all applicable and relevant laws and regulations and may seek assistance from the Department.

This guidance does not represent an authorization to use millings without obtaining site or project specific authorization as a Certificate of Authority to Operate a Beneficial Use Project pursuant to N.J.A.C. 7:26-1.7(g) except for the uses indicated above. Failure to obtain beneficial use approval prior to using asphalt millings except as indicated above shall subject the responsible party to enforcement action, including, but not limited to the assessment of substantial penalties and remediation of the inappropriately used millings. This guidance is offered without prejudice and shall not affect any ongoing or future enforcement actions the Department may take in response to past, present or future activities conducted by any person.

Revised: 04/02/01