Criteria for the Safe and Environmentally Protective Use of Granular Mine Tailings Known as “Chat”, 39325 [E7-13544]

Download as PDF cprice-sewell on PROD1PC71 with RULES Federal Register / Vol. 72, No. 137 / Wednesday, July 18, 2007 / Rules and Regulations ‘‘concerning aggregate exposure levels of consumers.’’ Further, Congress expressly recognized in the FQPA that this type of information is relevant and appropriate to a FQPA safety analysis. The statute, as amended by the FQPA, contains special provisions placing certain requirements upon EPA when it relies upon percent crop treated data in chronic risk assessments or anticipated residue data. (21 U.S.C. 346a(b)(2)(E) and (F)). Anticipated residue data is a term of art encompassing, among other things, data on the effect food processing has on pesticide residue levels. (70 FR at 46731–46732; Ref. 9) This term was in use by EPA well before such language was adopted in the FQPA. (Ref. 10; see, e.g., 54 FR 33044, 33045, August 11, 1989). Given this clear legal authority, the States’ vague allegations that the use of percent crop treated data or processing factors runs counter to the intent of the FQPA are meritless. 3. Use of percent crop treated data and individual exposure. The States’ claim that EPA’s use of percent crop treated data is not protective of individuals appears to be based on a lack of understanding of (1) the differences between acute and chronic risks and (2) the different techniques EPA uses for incorporating percent crop treated information into risk assessments. At times, EPA uses percent crop treated data in estimating exposure for both chronic and acute risk assessments. Such data, however, is used in a different manner in these assessments due to the differences in how acute and chronic exposures may result in harm. Moreover, as to both acute and chronic risk, EPA is concerned with the risk to an individual within major, identifiable population subgroups and incorporates percent crop treated data in a manner consistent with that concern. Further explanation of this approach is provided below. With a chronic risk, EPA is concerned with adverse effects that occur from the cumulative effect of repeated exposures over an extended time period (i.e., generally a period of 1 year or more for dietary exposure). The focus for a chronic exposure assessment is not on the level of any one exposure or even the variation in exposure from day-today so much as the general level of the continuing exposure. Thus, in estimating chronic pesticide exposure, EPA uses average daily pesticide exposure over the appropriate time period. In estimating average daily pesticide exposure, EPA takes into account that, given the national distribution of food in the United States, over a chronic timeframe a person will VerDate Aug<31>2005 10:08 Jul 18, 2007 Jkt 211001 consume food from a mixture of sources—regional, national, and international—as well as food grown at different times of the growing season. It is likely, therefore, that to the extent a food commodity is not uniformly treated with a given pesticide, the consumer will over time be exposed to a fairly representative sample of treated and untreated commodities. Accordingly, in refined exposure estimates for chronic pesticide exposures, EPA generally averages dietary pesticide exposure from a food based on the percentage of that food that has been treated with the pesticide. For example, if the estimated residue value for a pesticide on treated blueberries is 1 part per million (ppm) and half of the blueberry crop is treated, EPA would estimate the chronic pesticide exposure level from blueberries using the assumption that all blueberries contain 0.5 ppm of the pesticide (i.e., treated blueberries bear 1 ppm pesticide residues and over time a person gets an equal mixture of treated and untreated blueberries). EPA has long used percent crop treated data in this manner in chronic risk assessments and Congress explicitly recognized the appropriateness of this method of estimating pesticide exposure in the FQPA. (21 U.S.C. 346a(b)(2)(F)). With acute hazards, EPA is concerned with an adverse effect that can result from a single pesticide exposure or pesticide exposure over a single day to an individual. Thus, acute pesticide exposure assessments are designed to measure or estimate the maximum amount of residue that may be present in a single commodity serving or meal. EPA’s traditional method of using percent crop treated data in chronic risk assessments is problematic for acute risk assessments because it masks the highest levels of pesticide residues expected in food by averaging residue values from treated and untreated commodities in estimating pesticide exposure. For this reason, EPA, up until the mid–1990’s, did not use percent crop treated data in acute risk assessments. Instead, for acute risk assessments, EPA assumed that all commodities for which a pesticide had a tolerance contain residues at the tolerance level. That changed, however, with the introduction in the last decade of probabilistic risk assessment analysis. Probabilistic analysis, when used in pesticide exposure/risk assessment, is ‘‘a statistical method where the range of exposures to pesticide residues and the probability of exposure to any particular level is quantified.’’ (Ref. 3 at 22). Probabilistic exposure assessments are particularly helpful in realistically PO 00000 Frm 00025 Fmt 4700 Sfmt 4700 39325 estimating pesticide exposure levels from short-term exposures (e.g., a single meal) where there are multiple variables affecting pesticide exposure levels. For pesticide exposures from food these variables can include: i. Several different foods may be consumed in differing amounts; ii. The consumed foods may or may not have been treated with the pesticide in question; and iii. Foods that are treated may have a wide range of residue levels. Integral to probabilistic analysis of pesticide exposure is information on differing consumption patterns among individuals, the range of the levels of pesticide residue in treated food, and the percent of food that has been treated with a pesticide. Importantly, information on percent crop treated is not used in a probabilistic analysis to average residue levels between treated and untreated crops but rather solely to determine ‘‘the probability of [an individual] encountering a treated commodity.’’ (Ref. 11 at 14). Thus, percent crop treated information is used in a fundamentally different fashion in probabilistic acute risk assessments than in non-probabilistic chronic risk assessments. (The Agency currently does not use probabilistic techniques for chronic risk assessment due to limitations in its food consumption database.) The States’ challenge to EPA’s use of percent crop treated data for metribuzin is flawed because the States attack the appropriateness of the exposure estimate for a chronic risk assessment based on concerns more applicable to acute risk. The States argue that the adjustment of residue values by the percentage of the treated crop understates exposure of individual children because ‘‘if a child is eating treated carrots, he or she is consuming carrots that all contain pesticide residues . . . .’’ (Ref. 2 at 5). EPA generally agrees that if the concern is acute risk, it would be inappropriate to estimate acute exposure for non-blended commodities by multiplying the expected residue value in a food (e.g., carrots) by an estimate of the percent of carrots treated with the pesticide. Acute exposure assessments should be designed to identify actual exposures that can occur to an individual at a single meal or in a single day. For metribuzin (and alachlor and chlorothalonil as well), however, EPA used percent crop treated data only for estimating chronic pesticide exposure and risk. For chronic dietary risk, it is generally exposure over a period of at least 1 year that matters and over such a time period a person is likely to E:\FR\FM\18JYR1.SGM 18JYR1

Agencies

[Federal Register Volume 72, Number 137 (Wednesday, July 18, 2007)]
[Rules and Regulations]
[Page 39325]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E7-13544]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 260 and 278

[EPA-HQ-RCRA-2006-0097; FRL-8326-1]
RIN 2050-AG27


Criteria for the Safe and Environmentally Protective Use of 
Granular Mine Tailings Known as ``Chat''

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: The Environmental Protection Agency (EPA or the Agency) is 
promulgating mandatory criteria for the environmentally protective use 
of chat in transportation projects carried out, in whole or in part, 
with Federal funds. Specifically, chat used in such transportation 
projects will be safe and environmentally protective if it is used in 
asphalt concrete, in slurry seals, microsurfacing, or in epoxy seals 
for anti-skid on bridge decking. Chat used in such transportation 
projects will also meet EPA's criteria if it is used in Portland cement 
concrete, flowable fill, stabilized base, chip seals, or as road base 
providing, on a case-by-case basis, either: Synthetic Precipitation 
Leaching Procedure (SPLP, EPA SW-846 Method 1312) tests are conducted 
on the proposed material and the leachate testing results show that 
concentrations in the leachate do not exceed the Drinking Water 
Standards for lead and cadmium and the fresh water chronic National 
Recommended Water Quality Criterion for zinc of 120 ug/l; or EPA (or a 
State environmental Agency, if it chooses to do so) has determined, 
based on a site-specific risk assessment and after notice and 
opportunity for public comment, that the releases from the chat mixture 
in its proposed use will not cause an exceedance of the National 
Primary Drinking Water Standards for lead and cadmium in potential 
drinking water sources and the fresh water chronic National Recommended 
Water Quality Criterion for zinc of 120 ug/l in surface water. 
Furthermore, this rule also establishes a criterion that other uses of 
chat will be safe and environmentally protective and are acceptable if 
they are part of, and otherwise authorized by, a State or Federal 
response action undertaken in accordance with Federal or State 
environmental laws, with consideration of a site-specific risk 
assessment. This rule does not require that chat be sized (dry or wet) 
prior to its use, as long as this rule's criteria are complied with. 
EPA is also establishing recommended criteria as guidance on the 
environmentally protective use of chat for non-transportation cement 
and concrete projects. Finally, the Agency is establishing 
certification and recordkeeping requirements for all chat, except that 
under the jurisdiction of the U.S. Department of Interior, Bureau of 
Indian Affairs (BIA). The chat covered by this rule is from the lead 
and zinc mining areas of Oklahoma, Kansas and Missouri, known as the 
Tri-State Mining District.

DATES: This final rule is effective on September 17, 2007.
    The incorporation by reference of certain publications listed in 
this rule is approved by the Director of the Federal Register as of 
September 17, 2007.

ADDRESSES: The public docket for this final rule, Docket ID No EPA-HQ-
RCRA-2006-0097, contains the information related to this rulemaking, 
including the response to comment document. All documents in the docket 
are listed in the https://www.regulations.gov index. Although listed in 
the index, some information may not be publicly available, e.g., 
Confidential Business Information or other information the disclosure 
of which is restricted by statute. Certain other material, such as 
copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in https://www.regulations.gov or in hard copy at the EPA Docket, EPA/
DC, EPA West, Room 3334, 1301 Constitution Ave., NW., Washington, DC. 
The Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday 
through Friday, excluding legal holidays. The telephone number of the 
Public Reading Room is 202-566-1744, and the telephone number to make 
an appointment to view the docket is 202-566-0276.

FOR FURTHER INFORMATION CONTACT: Stephen Hoffman, U.S. Environmental 
Protection Agency, 1200 Pennsylvania Avenue, NW, Washington, DC, 20460-
0002, Mail Code 5306P; telephone number: 703-308-8413; fax number: 703-
308-8686; e-mail address: hoffman.stephen@epa.gov. Additional 
information on this rulemaking is also available on the internet at 
https://www.epa.gov/epaoswer/other/mining/chat/.
    The contents of this final rule are listed in the following outline

Contents of the Final Rule

I. General Information
    A. Does This Rule Apply to Me?
    B. What Are the Statutory Authorities for This Final Rule?

[[Page 39332]]

    C. Definitions and Acronyms Used in the Rule
II. Summary of This Rule
III. Background Information
IV. Rationale for This Rule and Response to Comments
    A. What Was the Process EPA Used to Develop This Action?
    B. What Criteria Are EPA Establishing for the Use of Chat?
    C. Relationship of This Rule to Other Federal Regulations and 
Guidance
    D. How Does This Rule Affect Chat Sales From Land Administered 
by BIA or Directly From Tribal Lands?
    E. How Does This Rule Affect CERCLA Liability, Records of 
Decision and Response Actions?
    F. How Does This Rule Affect the Use of Federal Funds 
Administered by the U.S. Department of Transportation for 
Transportation Construction Projects?
V. Impacts of the Final Rule
    A. What are the Potential Environmental and Public Health 
Impacts From the Use of Chat in Transportation Construction 
Projects?
    B. What are the Economic Impacts?
VI. State Authority
VII. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination With 
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children From 
Environmental Health and Safety Risks
    H. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use
    I. National Technology Transfer and Advancement Act
    J. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations
    K. Congressional Review Act

I. General Information

A. Does This Rule Apply to Me?

    These criteria affect the following entities: aggregate, asphalt, 
cement, and concrete facilities, likely limited to the Tri-State Mining 
District. However, other types of entities not identified could also be 
affected--that is, the list is not intended to be exhaustive, but to 
provide a guide for readers regarding those entities that potentially 
could be affected by this action. To determine whether your facility, 
company, business, organization, etc., is affected by this action, you 
should examine the applicability criteria of this preamble. If you have 
any questions regarding the applicability of this action to a 
particular entity, consult the person listed in the preceding FOR 
FURTHER INFORMATION CONTACT section.

B. What Are the Statutory Authorities for This Final Rule?

    Through Title VI, Section 6018 of the Safe, Accountable, Flexible, 
and Efficient Transportation Equity Act of 2005 (HR 3 or ``the Act''), 
Congress amended Subtitle F of the Solid Waste Disposal Act (42 U.S.C. 
6961 et seq.) by adding Sec. 6006. This provision requires the Agency 
to establish safe and environmentally protective criteria (including an 
evaluation of whether to establish a numerical standard for 
concentrations of lead and other hazardous substances) for the use of 
granular mine tailings from the Tar Creek, Oklahoma Mining District, 
known as `chat,' in cement and concrete projects and in transportation 
construction projects that are carried out, in whole or in part, using 
Federal funds. Section 6006(a)(4) requires that any use of the granular 
mine tailings in a transportation project that is carried out, in whole 
or in part, using Federal funds, meet EPA's established criteria.
    In establishing such criteria, EPA is required to consider ``the 
current and previous uses of granular mine tailings as an aggregate for 
asphalt, and any environmental and public health risks and benefits 
derived from the removal, transportation and use in transportation 
projects of granular mine tailings'' carried out, in whole or in part, 
using Federal funds. EPA is also required to consult with the Secretary 
of Transportation, and other Federal agencies in developing these 
criteria. RCRA section 2002(a) grants the Agency broad rulemaking 
authority, providing that the Administrator is authorized to prescribe 
``such regulations as are necessary to carry out his functions under 
this chapter.''
    While this is a regulation promulgated under RCRA, the rule sets 
the criteria that must be complied with at transportation construction 
projects funded, in whole or in part, with Federal funds. The U.S. 
Department of Transportation (DOT) has statutory responsibility over 
the dispersement of federal funds for transportation projects. 
Therefore, USDOT will make reference to this rule as one of the 
regulatory requirements it requires all states to adhere to as a 
condition of receiving Federal funds for transportation projects using 
chat.

C. Definitions and Acronyms Used in the Rule

     Asphalt--also known as asphalt cement, is liquid bitumen 
(heavy petroleum) used as the binder in cold, warm, and hot mix 
asphalt, chip seals, slurry seals, and microsurfacing. The term 
`asphalt' is sometimes used generically in place of cold, warm, or hot 
mix asphalt.
     Asphalt concrete--a layer, or combination of layers, 
composed of a compacted mixture of an asphalt binder and mineral 
aggregate.
     Pozzolanic--a siliceous material which when combined with 
calcium hydroxide in the presence of moisture exhibits cementitious 
properties.
     State or Federal response action--State or Federal 
response action undertaken pursuant to applicable Federal or State 
environmental laws and with consideration of site-specific risk 
assessments.
     Raw chat--unmodified lead-zinc ore milling waste that 
comes from the Tri-State Mining District.
     Washed chat--lead-zinc ore milling waste that has been 
wet-screened to remove the fine-grained fraction and which is sized so 
as not to pass through a number 40 sieve (0.425 mm opening size) or 
smaller.
     Sized chat--lead-zinc ore milling waste that has been wet-
screened (washed) or dry sieved to remove the fine-grained fraction 
smaller than a number 40 sieve (0.425 mm opening size).
    Non-transportation cement and concrete projects uses are:

--Construction uses of cement and concrete for non-residential 
structural uses limited to weight bearing purposes such as foundations, 
slabs, and concrete wall panels. Other uses include commercial/
industrial parking and sidewalk areas. Uses do not include any 
residential use of cement or concrete (e.g., residential parking areas, 
residential construction, concrete counter tops).

    Transportation construction uses are:

--Hot mix asphalt--a hot mixture of asphalt binder and size-graded 
aggregate, which can be compacted into a uniform dense mass. Hot mix 
asphalt also includes hot mix asphalt sub bases and hot mix asphalt 
bases.
--Portland cement concrete (PCC)--pavements consisting of a PCC slab 
that is usually supported by a granular (made of compacted aggregate) 
or stabilized base and a sub base. In some cases, the PCC slab may be 
overlaid with a layer of hot mix asphalt. PCC uses also include bridge 
supports, bridge decking, abutments, highway sound barriers, jersey 
walls, and non-residential side walks adjacent to highways.
--Flowable fill--a cementitious slurry consisting of a mixture of fine

[[Page 39333]]

aggregate or filler, water, and cementitious materials which is used 
primarily as a backfill in lieu of compacted earth. This mixture is 
capable of filling all voids in irregular excavations, is self 
leveling, and hardens in a matter of a few hours without the need of 
compaction in layers. Most applications for flowable fill involve 
unconfined compressive strengths of 2.1 MPa (300 lb/in2) or less.
--Stabilized base--a class of paving materials that are mixtures of one 
or more sources of aggregate and cementitious materials blended with a 
sufficient amount of water that result in the mixture having a moist 
nonplastic consistency that can be compacted to form a dense mass and 
gain strength. This class of base and sub base materials excludes 
stabilization of soils or aggregates using asphalt concrete or 
emulsified asphalt.
--Granular bases--road base typically constructed by spreading 
aggregates in thin layers of 150 mm (6 inches) to 200 mm (8 inches) and 
compacting each layer by rolling over it with heavy compaction 
equipment. The aggregate base layers serve a variety of purposes, 
including reducing the stress applied to the sub grade layer and 
providing drainage for the pavement structure. The granular sub base 
forms the lowest (bottom) layer of the pavement structure and acts as 
the principal foundation for the subsequent road profile.
--Embankment--a volume of earthen material that is placed and compacted 
for the purpose of raising the grade of a roadway above the level of 
the existing surrounding ground surface.
--Slurry seals--a material composed of emulsified asphalt, aggregate, 
and mineral fillers, such as Portland cement or lime which is applied 
as a thin coating on top of asphalt or PCC road surfaces.
--Micosurfacing--polymer-modified slurry seal.
--Cold mix asphalt--an asphalt/aggregate mixture composed of binders, 
soaps, or other chemicals which allow its use when cold or warm.
--Epoxy seals--the mixture of aggregate in epoxy binders. Epoxy seals 
are typically used as an anti-skid surface on bridge decking.
--Chip seals--a material composed of aggregate placed on top of a layer 
of an asphalt or asphaltic liquid binder. The aggregate may be rolled 
into the binder.

Abbreviations and Acronyms Used in This Document

ANSI American National Standards Institute
AASHTO American Association of State Highway and Transportation 
Officials
ASR Alkali-Silica Reaction
ASTM American Society for Testing and Materials
ATSDR Agency for Toxic Substances and Disease Registry
BDAT Best Demonstrated Available Technology
BIA Bureau of Indian Affairs
CAA Clean Air Act (42 USCA 7401)
CERCLA Comprehensive Environmental Response Compensation and Liability 
Act (42 USCA 9601)
CFR Code of Federal Regulations
CWA Clean Water Act (33 USCA 1251)
DOT Department of Transportation
EO Executive Order
EPA Environmental Protection Agency
FHWA Federal Highway Administration
FR Federal Register
ICR Information Collection Request
IEUBK Integrated Exposure Uptake Biokinetic (Model)
MCL Maximum Contaminant Level (Safe Drinking Water Act)
NIOSH National Institute for Occupational Safety and Health
NPL National Priorities List
ODEQ Oklahoma Department of Environmental Quality
OMB Office of Management and Budget
OSHA Occupational Safety and Health Administration
OU University of Oklahoma
OUs Operable Units
PCC Portland cement concrete
PEL Permissible Exposure Level
ppmv parts per million by volume
ppmw parts per million by weight
Pub. L. Public Law
RCRA Resource Conservation and Recovery Act (42 USCA 6901)
ROD Record of Decision
SMCL Secondary Maximum Contaminant Level (Safe Drinking Water Act)
SPLP Synthetic Precipitation Leaching Procedure (EPA SW 846 Method 
1312)
SSL (Superfund) Soil Screening Level
TCLP Toxicity Characteristic Leaching Procedure (EPA SW 846 Method 
1311)
TWA Time-Weighted Average
USACE U.S. Army Corp of Engineers
U.S.C. United States Code

II. Summary of This Rule

    On April 4, 2006, EPA published a Federal Register notice (64 FR 
16729) seeking comment on a proposed rule that would establish criteria 
for the safe and environmentally protective use of chat in 
transportation projects funded, in whole or in part, with Federal 
funds, as well as proposed guidance on the use of chat in non-
transportation cement and concrete projects. Based on a request to 
extend the comment period, the Agency again sought comment on this 
proposal on May 19, 2006 (71 FR 29117). The purpose of the proposed 
rule was to establish criteria that would identify environmentally 
protective uses of chat in federally funded transportation projects.
    The Agency received many comments in response to its April 4 and 
May 19, 2006 notices. Numerous commenters generally supported the 
proposed rule, while other commenters suggested changes to the 
proposal. After considering all comments, we are finalizing the 
proposed rule with several significant modifications. The final rule, 
similar to the proposed rule, establishes criteria allowing the use of 
chat in federally funded transportation projects when used in asphalt 
concrete for roadway surfaces and in asphalt for road bases and sub 
bases. Upon consideration of the comments, the Agency is expanding its 
criteria for chat in federally funded transportation projects to 
include chat used in slurry seals, microsurfacing, epoxy seals, and 
cold and warm mix asphalt. However, a significant modification to the 
proposal is that before chat can be used in Portland cement concrete 
(PCC) federally funded transportation projects, a person must show, on 
a case by case basis that: (1) Synthetic Precipitation Leaching 
Procedure (SPLP, EPA SW-846 Method 1312) tests are conducted on the 
proposed material and the leachate testing results show that 
concentrations in the leachate do not exceed the National Primary 
Drinking Water Standards for lead and cadmium and the fresh water 
chronic National Recommended Water Quality Criterion for zinc of 120 
ug/l; or (2) EPA (or a State environmental Agency, if it chooses to do 
so) has determined, based on a site-specific risk assessment and after 
notice and opportunity for public comment, that the releases from the 
chat mixture in its proposed use will not cause an exceedance of the 
National Primary Drinking Water Standards for lead and cadmium in 
potential drinking water sources and the fresh water chronic National 
Recommended Water Quality Criterion for zinc of 120 ug/l in surface 
water.
    The Agency is making these changes in response to comments received 
on the proposed rule, including comments

[[Page 39334]]

from the Peer Review Panel, which argued that there were insufficient 
data for the Agency to determine the range of risk from the use of chat 
in PCC. In addition, based on comment, the Agency also concluded that 
the use of chat in flowable fill, stabilized based, chip seals and as 
road base may only be allowed if a case-by-case demonstration is made, 
as described above. This rule's approach will generate the data needed 
to determine if such uses are safe and environmentally protective. Such 
an approach is also similar to that already used by a number of states 
when they make beneficial use determinations.
    The Agency wishes to emphasize that the use of chat in 
transportation projects, funded in whole or in part using Federal 
funds, does not affect a person's obligation to comply with existing 
state or Federal materials specifications. Further discussion of this 
matter is noted in the sections entitled, Physical and Chemical 
Characteristics of Chat and Relationship of this Rule to other Federal 
Regulations and Guidance.
    The Agency has retained its proposal that chat authorized by a 
State or Federal response action undertaken in accordance with Federal 
or State environmental laws need not comply with the criteria in 
sections 278.3 (a) or (b). Such response actions are undertaken with 
consideration of site-specific risk assessments. For example, 
unencapsulated uses of chat may be authorized in a State or Federal 
remediation action. This rule also retains the certification 
requirement, since the Agency believes that such notice is important 
for states and the public to know how and where chat is used in 
transportation.
    EPA believes that this rule will encourage the environmentally 
sound use of chat in transportation projects funded, in whole or in 
part, with Federal funds.

III. Background Information

1. What Is Chat?

    Chat is the waste material that was generated from the extraction 
and beneficiation of lead/zinc minerals to produce lead/zinc 
concentrate in the Tri-State Mining District of Southwest Missouri, 
Southeast Kansas and Northeast Oklahoma. Chat is primarily composed of 
chert, a very hard rock. The primary properties that make chat useful 
in asphalt-based road materials, Portland cement concrete, and epoxies 
are grain size distribution, durability, non-polishing, and low 
moisture absorption.
    In 1980, Congress enacted the Solid Waste Disposal Act Amendments 
(Pub. L. 96-482) which added section 3001(b)(3)(A)(ii) (the Bevill 
Amendment) to RCRA. This section required the Agency to study 
extraction/beneficiation wastes and in 1989 the Agency promulgated a 
rule (54 FR 36592) which exempts extraction/beneficiation wastes from 
regulation under the RCRA Subtitle C hazardous waste regulations (see 
(40 CFR 261.4(b)(7)). Therefore, chat is a ``Bevill exempt'' waste and 
is not subject to regulation under RCRA Subtitle C. This exemption does 
not, however, affect CERCLA jurisdiction over chat, since chat contains 
hazardous substances, nor does it affect the jurisdiction of RCRA 
section 7003, as long as the chat is a solid waste.

2. What Is the Areal Scope for This Action?

    The Act directed EPA to develop criteria for chat from the Tar 
Creek, Oklahoma Mining District. However, there is no definition of the 
term ``Tar Creek Oklahoma Mining District.'' Available literature 
references the ``Tar Creek Superfund site,'' which is in Oklahoma, but 
the term ``mining district'' is only used in reference to the ``Tri-
State Mining District.'' For purposes of this final rule, the areal 
scope includes chat originating from the Tri-State Mining District of 
Ottawa County, Oklahoma, Cherokee County of southeast Kansas, and 
Jasper, Newton, Lawrence and Barry Counties of southwest Missouri, 
regardless of where it is used.
    In 1979, the U.S. Bureau of Mines completed a study to identify all 
mined areas and mine-related hazards which confirmed that lead-zinc 
mining covers a portion of each of the States of Kansas, Missouri, and 
Oklahoma. This area is the same area known as the Tri-State Mining 
District.
    Chat located in this historical mining district is a product of 
similar mineralization processes that sets it aside from related lead-
zinc mineralization districts elsewhere in the United States. The Tri-
State mineralization is specifically associated with wall rock 
alteration into dolomite and microcrystalline silica (chert). The term 
chat is derived from the word ``chert,'' referring to the cherty 
wallrock found in this mining district. The lead/zinc ore and its 
related waste, chat, in this district also have a well defined lead to 
zinc ratio.
    For over one hundred years of activity ending in 1970, the Tri-
State Mining District has been the source of a major share of all the 
lead and zinc mined in the United States. Surface piles of chat, as 
well as underground mining areas, extend uninterrupted across the 
Oklahoma-Kansas State line. In the proposal, the Agency did not include 
Lawrence and Barry counties in southwest Missouri as part of the areal 
extent of the rule, but requested comment on whether it would be 
reasonable to include them (see 71 FR 16732). Commenters requested that 
the Agency expand the scope of the rule to include these two counties 
in southwest Missouri. Based on communication with state regulatory 
officials in Kansas, Missouri, and Oklahoma and review of mineral 
geology studies, EPA concludes that there is no real factual 
distinction between chat derived from these three states, and believes 
that it is reasonable to apply this rule to the areal extent of all 
chat generated and currently located in the following counties: Ottawa 
county, Oklahoma, Cherokee county, Kansas, and Newton, Jasper, Lawrence 
and Barry counties in Missouri.

3. Are There Any Current Regulations of Asphalt, Portland Cement 
Concrete or Chat Washing Facilities?

    Based on the Agency's review of existing state and federal 
regulations, the Agency did not propose to apply any additional 
regulations on chat washing or hot mix asphalt and Portland cement 
concrete plants, although the Agency solicited comment on whether it 
would be prudent for this rule to apply additional controls, over those 
that currently exist, to address environmental releases from these 
types of facilities.\1\ Specifically, at proposal, the Agency assessed 
existing regulations in Oklahoma, Kansas, and Missouri for hot mix 
asphalt plants and Portland cement concrete plants to determine whether 
those operations are appropriately regulated to address environmental 
releases for such facilities. (See memorandum entitled: Evaluation of 
State Regulations in the docket.) Those regulations set standards for 
point and fugitive air emission sources (see Kansas: K.A.R. 28-19-500, 
Missouri: 10 CSR 10-6.170, and Oklahoma: OAC 252:100-7/8/29) and also 
set requirements for water discharges from point source discharges (see 
Kansas: K.A.R. 28-16, Missouri: 10

[[Page 39335]]

CSR 20-6.200, and Oklahoma: OAC 252:606-5-5). In addition, Oklahoma, 
Missouri and Kansas all require that trucks transporting aggregate must 
be covered to reduce fugitive emissions and reduce damage to other 
vehicles from windblown debris. The Bureau of Indian Affairs (BIA) also 
requires that trucks transporting chat from Tribal lands be covered to 
prevent blowing dust from transport.
---------------------------------------------------------------------------

    \1\ It should be noted that the statute does not require the 
Agency to set criteria for facilities that prepare chat prior to its 
use, but restricts the activities for which the Agency is to 
establish criteria for the use of chat in transportation projects 
funded, wholly or in part, with Federal funds. Nevertheless, the 
Agency evaluated the potential for environmental releases from these 
types of facilities--chat washing, hot mix asphalt and Portland 
cement concrete plants as part of the rulemaking.
---------------------------------------------------------------------------

    The Agency also assessed existing regulations in Oklahoma, Kansas, 
and Missouri for chat washing facilities to determine whether chat 
``washing'' operations are adequately managed.\2\ There are two 
commercial chat washing facilities in the Tri-State area and both are 
located within the Tar Creek Superfund site. While the States do not 
have specific regulations applicable to chat washing facilities, these 
facilities are subject to State general fugitive air emissions and 
general storm water discharge regulations. These general State permits 
require that fugitive dusts and runoff be controlled in a fashion so 
that dusts and other pollutants do not leave the property line or the 
boundary of the construction activity. In addition, because the two 
chat washing facilities are located within the Tar Creek Superfund 
site, the Agency may rely on CERCLA authority to establish any 
additional conditions that are considered necessary to be safe and 
environmentally protective.
---------------------------------------------------------------------------

    \2\ While EPA recognizes that some chat is washed or sized prior 
to being used, today's final rule does not require that chat be 
washed prior to its use. Therefore, imposing additional requirements 
for chat washing facilities would seem inappropriate.
---------------------------------------------------------------------------

    The BIA is also establishing air and water standards for chat 
washing facilities located on Tribal lands and lands administered by 
BIA. BIA's requirements include that the chat washing facility manage 
waste water discharges so that they do not exceed State standards, that 
fugitive dusts be controlled, and that fines are handled and disposed 
of so that they do not contaminate ground water. In addition, BIA 
requires all purchasers of chat from Tribal lands, or lands 
administered by BIA, to certify that the chat will be used in 
accordance with authorized uses set forth in EPA fact sheets and other 
guidance. (See report titled, Chat Sales Treatability Study Workplan 
for the Sale of Indian-Owned Chat within the Tar Creek Superfund Site, 
Ottawa County, Oklahoma, June 23, 2005.).
    A number of commenters noted their concern that existing 
regulations do not adequately control releases from these types of 
facilities. As noted above, the Agency reviewed existing state and 
Federal regulations of these facilities, and determined that they are 
in fact subject to regulation of their releases and that the existing 
regulations assure safe and environmentally protective conditions at 
these facilities--that is, hot mix asphalt plants, PCC plants and chat 
washing facilities. Therefore, the Agency is not promulgating 
additional controls for these facilities.

4. Are There Existing Criteria for the Use of Chat?

    As noted in a 2005 University of Oklahoma (OU) report, the Oklahoma 
Department of Environmental Quality (ODEQ) has determined that the 
following transportation uses of raw chat are inappropriate: Use in 
residential driveways and as gravel or unencapsulated surface material 
in parking lots, alleyways, or roadways (See A Laboratory Study to 
Optimize the Use of Raw Chat in Hot Mix Asphalt for Pavement 
Application: Final Report). ODEQ also identified the following non-
transportation uses of raw chat that are deemed inappropriate for 
residential use:
--Fill material in yards, playgrounds, parks, and ball fields
--Playground sand or surface material in play areas
--Vegetable gardening in locations with contaminated chat
--Surface material for vehicular traffic (e.g., roadways, alleyways, 
driveways, or parking lots)
--Sanding of icy roads
--Sandblasting with sand from tailings ponds or other chat sources
--Bedding material under a slab in a building that has underfloor air 
conditioning or heating ducts
--Development of land for residential use (e.g., for houses or for 
children's play areas, such as parks or playgrounds) where visible chat 
is present or where the lead concentration in the soil is equal to or 
greater than 500 mg/kg unless the direct human contact health threat is 
eliminated by engineering controls (e.g., removing the contaminated 
soil or capping the contaminated soil with at least 18 inches of clean 
soil)

    EPA Region 6 also issued a Tar Creek Mining Waste Fact Sheet on 
June 28, 2002 that identified the following as acceptable uses of chat: 
(1) Applications that bind (encapsulate) the chat into a durable 
product (e.g., concrete and asphalt), (2) applications that use the 
chat as a material for manufacturing a safe product where all waste 
byproducts are properly disposed, and (3) applications that use the 
chat as sub-grade or base material for highways (concrete and asphalt) 
designed and constructed to sustain heavy vehicular traffic. This fact 
sheet also incorporated the ODEQ list of unacceptable residential uses 
of chat.
    In addition, EPA Region 7 issued a Mine Waste Fact Sheet in 2003 
that identified the uses of chat that are not likely to present a 
threat to human health or the environment. Those uses are: (1) 
Applications that bind material into a durable product; these would 
include its use as an aggregate in batch plants preparing asphalt and 
concrete, (2) applications below paving on asphalt or concrete roads 
and parking lots, (3) applications that cover the material with clean 
material, particularly in areas that are not likely to ever be used for 
residential or public area development, and (4) applications that use 
the material as a raw product for manufacturing a safe product. The 
fact sheet also lists mine waste (chat) uses that may not be safe and 
environmentally protective and are similar to those listed by ODEQ and 
the Region 6 fact sheet. However, the Region 7 fact sheet also lists 
use as an agricultural soil amendment to adjust soil alkalinity as a 
use that may not be safe and environmentally protective.
    This rule is more restrictive than the 2002/2003 Region 6 and 7 
fact sheets. Therefore, the Agency is issuing new fact sheets on the 
use of chat from the Tri State Mining District in transportation 
construction projects funded, in whole or in part, with Federal funds 
and in non-transportation non-residential uses of chat. The new fact 
sheets are consistent with this rule. The fact sheets are available at 
https://www.epa.gov/epaoswer/other/mining/chat/.

5. Physical and Chemical Characteristics of Chat

    This section provides information on the physical characteristics, 
such as hardness, soundness (durability), gradation, shape and surface 
texture, and chemical characteristics, such as the leaching potential 
of chat.
Physical Characteristics
    In an OU study (A Laboratory Study to Optimize the Use of Raw Chat 
in Hot Mix Asphalt for Pavement Application: Final Report (August 
2005)), the specific gravity of the raw chat was found to be 2.67, 
which is similar to some commonly used aggregates, such as limestone 
and sandstone.
    According to an ODEQ study (Summary of Washed and Unwashed Mining 
Tailings (Chat) from Two Piles at the Tar Creek Superfund Site, Ottawa 
County Oklahoma, Revised June 2003), chat consists of materials ranging 
in diameter from 15.875 mm (\5/8\ inch) to

[[Page 39336]]

less than 0.075 mm (the size fraction that passes the No. 200 sieve).
    Since raw chat is a crushed material from mining operations, raw 
chat particles have fractured faces. Raw chat also has numerous inter-
granular voids in the loose aggregate form. The more angular the 
aggregate the higher the amount of voids. The uncompacted void content 
or the fine aggregate angularity of raw chat was found to be 46%. This 
value exceeds the higher fine aggregate angularity required by most 
State DOTs.
    Raw chat is harder than some other aggregates, such as limestone. 
The L.A. abrasion value (determined by the Test for Resistance to 
Degradation of Aggregate by Abrasion and Impact in the Los Angeles 
Abrasion Machine) of raw chat was found to be 18% which is lower than 
that of limestone (23%) used in the OU study. This makes chat a good 
material in road surfaces since it does not wear down as fast as other 
aggregates.
    Cubical shape is another desirable property of a good aggregate. 
The coarse aggregate in raw chat (particles retained on a 4.75 mm 
(4) sieve) has less than 5% flat or elongated particles. 
Therefore, chat is viewed as a desirable aggregate material.
    State DOTs specify minimum aggregate durability indices depending 
on the type of road surface. In the OU study, the aggregate durability 
index of raw chat was found to be 78%. The insoluble residue of raw 
chat was found to be 98%. Oklahoma DOT has established a 40% insoluble 
requirement for combined aggregates used in a surface layer of hot mix 
asphalt, for the purpose of skid resistance. Surface treatments, like 
microsurfacing, have higher insoluble residue requirements. Thus, the 
use of insoluble aggregates like chat in hot mix asphalt surface mixes 
and other surface treatments can improve the skid resistance and safety 
of pavements.
    State DOTs also specify aggregate requirements for hot mix asphalt 
and PCC. Most State DOTs, including Kansas, Oklahoma and Missouri, have 
adopted aggregate standards developed by the American Association of 
State Highway and Transportation Officials (AASHTO). According to 
AASHTO, the 0.075 mm (200) sieve size is the dividing line 
between sand-size particles and the finer sized particles defined as 
silts and clays. These finer particles often adhere to larger sand and 
gravel particles and can adversely affect the quality of hot mix 
asphalt and Portland cement concrete. The AASHTO standards for Fine 
Aggregate for Bituminous Paving Mixtures (M 29-03) and Fine Aggregate 
for PCC (M 6-03) specify limits for the amount of aggregate, on a 
percent mass basis, in hot mix asphalt and Portland cement concrete 
according to aggregate size and gradation. The aggregate sizes included 
in the AASHTO standards range from .075 mm to 9.5 mm which is within 
the range of particles found in raw chat. The AASHTO standards do not 
preclude the use of fine chat particles in hot mix asphalt or PCC. 
Depending on the designated grading, however, AASHTO limits particles 
finer than sieve size 50 in the range of 7% to 60% for 
aggregate in asphalt. Fine aggregate for use in concrete is limited by 
the States of Oklahoma and Missouri to between 5% and 30% for particles 
less than sieve size 50, while the corresponding values in 
Kansas are 7% to 30%. Therefore, chat used in asphalt or PCC must meet 
sizing specifications. This can be accomplished either by the raw chat 
meeting these specifications as is, or mixing the raw chat with other 
aggregates, by dry sizing, or by washing (wet sizing) the chat.
    Current law requires that the chat used as an aggregate in 
transportation projects meet existing State Department of 
Transportation or Federal Highway Administration material 
specifications, which assure that the road surface, composed of hot, 
warm or cold mix asphalt, concrete or epoxy, is durable and will not 
degrade prematurely. As discussed below, in light of these existing 
requirements, EPA concluded that it was not necessary to establish any 
additional material specifications for the use of chat as an aggregate 
in federally funded transportation projects to ensure that when chat is 
used, it will be safe and environmentally protective.
Chemical Characteristics
    Dames and Moore, 1993 and 1995; Sampling and Metal Analysis of Chat 
Piles in the Tar Creek Superfund sites for the Oklahoma Department of 
Environmental Quality, 2002, and Datin and Cates; Summary of Washed and 
Unwashed Mining Tailings (Chat) from Two Piles at the Tar Creek 
Superfund Site, Ottawa County Oklahoma, Revised June 2003, provide data 
on metals concentrations in washed and unwashed (or raw) chat. The 
Dames and Moore study indicated that total lead concentrations in the 
raw chat ranged from 100 mg/kg to 1,660 mg/kg, while the Datin and 
Cates study noted that mean total lead concentrations from the raw chat 
piles located throughout the Tri-State area ranged between 476 to 971 
mg/kg. The AATA International, Inc. December 2005; Draft: Remedial 
Investigation Report for Tar Creek OU4 RI/FS Program found that the 
concentration of lead in the raw chat ranged from 210 mg/kg to 4,980 
mg/kg, with an average of 1,461 mg/kg; cadmium ranged from 43.1 mg/kg 
to 199.0 mg/kg, with an average of 94.0 mg/kg; and zinc ranged from 
10,200 mg/kg to 40,300 mg/kg, with an average of 23,790 mg/kg.
    These studies show that as chat sizes become smaller, their metals 
content increases. The cited Datin and Cates report, Summary of Washed 
and Unwashed Mining Tailings (Chat) from Two Piles at the Tar Creek 
Superfund Site, Ottawa County Oklahoma, Revised June 2003, shows that 
total metals testing of wet screened material (larger fractions) 
resulting from chat washing have lead concentrations which range from 
116 to 642 mg/kg, a range much lower than raw chat. Therefore, the data 
show that chat washing generates chat aggregate (greater than sieve 
size 40) with considerably lower metals concentrations than 
raw chat.\3\
---------------------------------------------------------------------------

    \3\ The Datin and Cates report also provides TCLP testing data 
that indicates the dry sieve sizes greater than 40 would 
not exceed 5 mg/l, as well as data on wet screened material (larger 
fractions) that also shows that the leaching potential of this 
material is below 5 mg/l (1.028 to 3.938 mg/l). 5 mg/l is the level 
of lead that defines whether a waste is hazardous under RCRA 
subtitle C. Thus, this is another indication that the larger sizes 
of chat have lower lead concentrations than do smaller sized chat 
particles. (Note: As indicated earlier, chat is considered a Bevill 
mining waste and is thus, exempt from regulation under RCRA Subtitle 
C. However, we are using the TCLP leachate value for lead simply as 
a comparative measure to evaluate the leaching characteristics of 
chat.)
---------------------------------------------------------------------------

6. What Are the Environmental and Health Effects Associated With 
Pollutants Released From Raw Chat?

    The Tri-State Mining District includes four National Priorities 
List (NPL) Superfund sites that became contaminated from the mining, 
milling, smelting, and transportation of ore and the management 
practices for chat. These sites are located in Tar Creek in Ottawa 
County, Oklahoma, Cherokee County in southeast Kansas, and in Jasper 
and Newton Counties in southwest Missouri. Superfund cleanup activities 
related to the millions of tons of mining waste that were deposited on 
the surface of the ground at these sites have been designated as 
Operable Units (OUs). OUs are groupings of individual waste units at 
NPL sites based primarily on geographic areas and common waste sources.
    Certain uses of raw chat have caused threats to human health and 
the environment as a result of the concentrations of lead, cadmium and 
zinc present in the chat.\4\ Evaluation of

[[Page 39337]]

raw chat also indicates that this waste in most unencapsulated uses has 
the potential to leach lead into the environment at levels which may 
cause threats to humans (i.e. elevated blood lead concentrations in 
area children). Such threats have been fully documented in Records of 
Decision (RODs) for the OUs at these NPL sites (See Tri-State Mining 
District RODs in the docket to this action). Copies of Site Profiles 
and RODs can be searched at: https://www.epa.gov/superfund/sites/rods/
index.htm.
---------------------------------------------------------------------------

    \4\ Information regarding the specific threats to human health 
from lead, cadmium and zinc can be found in the Agency for Toxic 
Substances and Disease Registry (ATSDR) Fact Sheet for Lead, 
September 2005, the ASTDR Fact Sheet for Cadmium, June 1999 and the 
ATSDR Fact Sheet for Zinc, September 1995, all of which are 
available in the Docket to today's final rule.
---------------------------------------------------------------------------

IV. Rationale for This Rule and Response to Comments

A. What Was the Process EPA Used to Develop This Action?

    In developing the proposed rule, the Agency initially reviewed 
information concerning the environmental effects of the improper 
placement and disposal of chat found in the RODs cited above for the 
four NPL sites located in the Tri-State Mining District (Tar Creek, 
Jasper County, Cherokee County, Newton County). The Agency then 
reviewed reports which identified current or past uses of chat, 
primarily studies prepared to support Oklahoma Governor Keating's 
Taskforce (Governor Frank Keating's Tar Creek Superfund Task Force, 
Chat Usage Subcommittee Final Report, September 2000) and research on 
chat uses conducted by OU (A Laboratory Study to Optimize the Use of 
Raw Chat in Hot Mix Asphalt for Pavement Application: Final Report 
August 2005), as well as interviewed the principal authors of the OU 
studies to further evaluate their findings. Additionally, the Agency 
interviewed representatives from the Departments of Transportation in 
Oklahoma, Kansas, and Missouri and met with the U.S. Department of 
Transportation, Federal Highway Administration to discuss the use of 
aggregate substitutes in road surfaces and relied on the joint EPA/FHWA 
document of the use of wastes in highway construction [User Guidelines 
for Waste and Byproduct Material in Pavement Construction, FHWA, 1997 
(https://www.rmrc.unh.edu/Partners/UserGuide/begin.htm)]. Furthermore, 
EPA met with the BIA to discuss BIA requirements for the sale of chat 
on Tribal lands. The Agency also conducted a series of interviews with 
the environmental regulatory agencies in the three involved States to 
further identify acceptable versus unacceptable uses of chat. Moreover, 
the Agency conducted interviews with companies which either used chat 
at that time or had used chat previously. As part of this effort, EPA 
representatives visited the Tri-State area to observe the condition of 
chat piles and confirm the location of chat washing and asphalt 
companies in the area. Finally, the Agency has communicated with the 
tribal members in the Tri-State area to inform them about this action 
and seek information about current uses.
    Based on our review of the reports and interviews noted above, the 
Agency published a Proposed Rule on April 4, 2006, in which we 
specifically solicited comment on a number of issues (see 64 FR 16729). 
The Agency received approximately 20 comments on the proposal. The 
Agency's response to the comments received can be found in the docket 
for this rule (see Response to Comments Document). In addition, the 
Agency conducted an external Peer Review of the risk screen conducted 
for the proposal. The Peer Review Panel submitted comments to the 
Agency and based on those comments, the Agency conducted an additional 
risk screen of chat dusts from milling of road surfaces containing chat 
to determine if such an activity presented a risk to human health and 
the environment. Both the original risk screen and subsequent risk 
evaluations are noted in the risk section of the preamble to this final 
rule, and are also in the Docket to this final rule. The Agency also 
met with representatives from the Department of Transportation to seek 
their input on a number of issues raised by commenters. Finally, the 
Agency consulted with the Tribal interests to assure that their 
comments were fully understood by the Agency. Based on the additional 
work noted above, as well as responding to comments, the Agency is 
today finalizing the chat rule.

B. What Criteria Are EPA Establishing for the Use of Chat?

1. Transportation Construction Uses
    Transportation construction uses of chat addressed in this final 
rule are those construction activities that occur as part of 
transportation construction projects that are funded, wholly or in 
part, with Federal funds. The Agency has evaluated all the 
transportation construction uses and has concluded that chat used in 
hot, warm, or cold mix asphalt, slurry seals, microsurfacing and in 
epoxy seals, or other uses of chat that are evaluated on a case-by-case 
basis will be safe and environmentally protective.
a. What Is the Final Action?
    This final rule establishes criteria that chat used in 
transportation construction projects that are funded, wholly or in 
part, with Federal funds, must meet as a condition of receiving Federal 
transportation funding. Specifically, those criteria define the 
following uses to meet the statutory standards: chat that is used in 
asphalt concrete, slurry seals, microsurfacing, or epoxy seals. The use 
of chat also meets EPA's criteria if it is used in PCC, stabilized road 
base, granular road base, flowable fill, and in chip seals, provided 
that on a case-by-case basis: (1) Synthetic Precipitation Leaching 
Procedure (SPLP, EPA SW-846 Method 1312) tests are conducted on the 
proposed material and the leachate testing results show that 
concentrations in the leachate do not exceed the National Primary 
Drinking Water Standards for lead and cadmium and the fresh water 
chronic National Recommended Water Quality Criterion for zinc of 120 
ug/l; or (2) EPA (or a State environmental Agency, if it chooses to do 
so) has determined, based on a site-specific risk assessment and after 
notice and opportunity for public comment, that the releases from the 
chat mixture in its proposed use will not cause an exceedance of the 
National Primary Drinking Water Standards for lead and cadmium in 
potential drinking water sources and the fresh water chronic National 
Recommended Water Quality Criterion for zinc of 120 ug/l in surface 
water.
    EPA has also established a criterion that other chat uses will be 
safe and environmentally protective if they are part of, and otherwise 
authorized by a State or Federal response action undertaken in 
accordance with Federal or State environmental laws. Such response 
actions are undertaken with consideration of site specific risk 
assessments.
    In addition, for all chat used in transportation construction 
projects that are funded, in whole or in part, using Federal funds that 
is not subject to the BIA Chat Use Certification requirements described 
in Section IV.B1, the Agency is establishing a certification 
requirement similar to that required by BIA. Specifically, any acquirer 
of the chat must submit a signed, written certification that the chat 
will be used in accordance with EPA's criteria. The certification will 
also include the location of origin of the chat and the amount of chat 
acquired.
    The certification must be provided to the environmental regulatory 
agency in the State where the chat is used, except for chat acquired on 
lands administered

[[Page 39338]]

by the BIA which is subject to the BIA certification requirements. The 
Agency is also requiring that if the acquirer sells or otherwise 
transfers the chat, the new owner of the chat must also submit a 
signed, written certification as described in this section. Most 
commenters did not support the certification requirement, because they 
believe that it would increase the cost of using chat. As noted 
earlier, BIA has established a chat sales program affecting chat sales 
from tribal lands. That program includes a certification requirement 
similar to that found in this rule. The Agency believes that 
certification is necessary to assure that chat users comply with 
today's criteria, as well as serving as a means to inform State 
environmental agencies about the use of chat in their state. The Agency 
has reviewed the burden on industry to fill out and maintain the 
certification records and does not find that such a requirement is 
burdensome. Moreover, the Agency believes that the certification 
requirement will provide important information to state environmental 
agencies to ensure that the chat is used as required under this rule.
    This rule also requires that chat users maintain records. The 
Agency is requiring that the acquirer, or any other person that 
receives a copy of the certification, maintain a copy of the 
certification in its files for three years following transmittal to the 
State environmental regulatory agency. If the use is based on a case-
by-case basis, the acquirer must maintain copies of any SPLP leachate 
testing results or any site-specific risk assessment for three years.
b. What is the rationale for the Rule?
    The Agency is basing this action on our review of various studies 
and data that show that certain uses of chat are safe and 
environmentally protective.
i. Hot Mix Asphalt
    There are a number of factors which lead us to conclude that chat 
used in hot mix asphalt is safe and environmentally protective:
    Several studies have been conducted on the use of chat in hot mix 
asphalt. The most comprehensive study was conducted by the OU School of 
Civil Engineering and Environmental Science. OU published their 
findings in a report titled, A Laboratory Study to Optimize the Use of 
Raw Chat in Hot Mix Asphalt for Pavement Application: Final Report 
(August 2005). OU tested the durability and leaching potential of a 
variety of mixtures of hot mix asphalt with raw chat for road surfaces 
and for road bases. In addition, OU milled (sawed) samples to simulate 
weathering. The Agency relied on these findings as one of the principal 
sources of data supporting the use of chat in hot mix asphalt road 
surfaces and asphalt road bases. The OU study also confirms the 
findings of an earlier study conducted by the U.S. Army Corp of 
Engineers (Tar Creek Superfund Site, Ottawa County, Oklahoma, Final 
Summary Report: Chat--Asphalt Paved Road Study USACE--Tulsa District, 
February 2000). Specifically:
     Comparison of the Synthetic Precipitation Leaching 
Procedure (SPLP) results of milled (weathered) chat asphalt samples in 
the OU study with the National Primary and Secondary Drinking Water 
Standards (www.epa.gov/safewater/mcl.html), without dilution and 
attenuation, show that milled surface and road base mixtures did not 
exceed the primary drinking water standard for lead \5\ (0.015 mg/l) or 
cadmium (0.005 mg/l). The OU results also show that milled asphalt road 
bases and surfaces did not exceed the secondary drinking water standard 
for zinc (5 mg/l).\6\
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    \5\ The National Primary Drinking Water Regulations set a 
Maximum Contaminant Level Goal of zero and a Treatment Technique 
action level of 0.015mg/l for lead.
    \6\ Several hot mix asphalt samples were also tested in the OU 
study using the Toxicity Characteristic Leaching Procedure (TCLP). 
For surface samples, TCLP average concentrations for lead ranged 
from <0.005 mg/l to a high of 0.46 mg/l. TCLP average concentrations 
for cadmium ranged from <0.010 mg/l to 0.223 mg/l and zinc 
concentration averages ranged from 11.3 mg/l to 28.53 mg/l. Road 
base samples usually have higher metals concentrations than do 
surface samples. For road base samples, average TCLP lead 
concentrations ranged from 0.069 mg/l to 2.008 mg/l, while average 
TCLP cadmium concentrations ranged from 0.011 mg/l to 0.087 mg/l and 
average TCLP zinc concentrations ranged from 19.9 mg/l to 41.33 mg/
l.
---------------------------------------------------------------------------

     The TCLP test was designed as a screening test to simulate 
leaching of materials in a municipal solid waste landfill. The SPLP 
test is also a screening test to simulate leaching of materials when 
exposed to acid rain. It is highly unlikely that road surfaces would be 
exposed to leaching conditions found in municipal solid waste 
landfills. Therefore, the Agency believes that of these two tests, the 
SPLP tests are likely to better mimic the leaching potential of such 
mixtures when they are to be used in road construction.
     The OU study tested unweathered and milled samples. The 
Agency believes milled samples represent worst case scenarios because 
milling exposes more surface area to leaching.
     In a dissertation submitted to the University of New 
Hampshire titled, Contributions to Predicting Contaminant Leaching from 
Secondary Material Used in Roads, Defne S. Apul, September 2004, the 
author noted that if pavement is built on highly adsorbing soils, the 
concentrations of leached contaminants reaching groundwater are more 
than several orders of magnitude lower than the MCLs.
    The ODEQ report entitled, Summary of Washed and Unwashed Mining 
Tailings (Chat) from Two Piles at the Tar Creek Superfund Site, Ottawa 
County Oklahoma, Revised June 2003, also evaluated leachate from 
asphalt containing chat removed from the Will Rogers Turnpike located 
near Quapaw, Oklahoma. This evaluation was conducted to determine if 
asphalt concrete containing chat that is removed at the end of its 
useful life poses contamination threats from metals leaching into the 
environment. TCLP results for lead ranged from less than 0.050 mg/l to 
0.221 mg/l. There are no SPLP test data in this report. However, based 
on best professional judgment and review of TCLP versus SPLP results, 
EPA believes that if SPLP tests were conducted, there would be a 
reduction in lead concentrations of approximately one order of 
magnitude as compared to the results of TCLP tests. Therefore, we 
believe that SPLP results would not exceed the MCL for lead. Based on 
these results, EPA does not believe the disposal of chat asphalt should 
present risks to the environment. The Agency sought comment on whether 
data was available which would further clarify whether the leachate 
potential from end of life use of chat in asphalt presented any 
threats. The Agency did not receive any comments or information that 
disproves the Agency's contention that it is unlikely that end of life 
chat asphalt will adversely affect the environment.
    Finally, the Peer Review Panel that reviewed and commented on the 
risk screen for the proposed rule concluded that the use of chat in hot 
mix asphalt road surfaces and in asphalt road bases are safe and 
environmentally protective. The Agency, therefore, concludes that the 
use of chat in hot mix asphalt for pavement (which accounts for about 
95% of the current chat usage), asphalt base, and asphalt sub base are 
safe and environmentally protective. EPA does not believe that it is 
necessary to establish specifications of what constitutes ``hot mix 
asphalt'' because transportation construction uses are required to 
comply with Federal and State Department of Transportation material 
specifications. These specifications delineate requirements which 
ensure that when chat is used in hot mix asphalt, the resulting product 
will be structurally stable. It is

[[Page 39339]]

recommended that chat users first determine if the proposed use meets 
State or Federal DOT materials specifications, since adherence to them 
is separately required under current law.
ii. Slurry Seal, Microsurfacing, Warm Mix Asphalt, Cold Mix Asphalt, 
and Epoxy Seal
    While the proposal limited the use of chat as a direct ingredient 
in hot mix asphalt (including use as road pavement, asphalt base and 
asphalt sub base), many commenters requested that the Agency expand the 
scope of the criterion to include other road surface uses associated 
with asphalt that they believed retard the leaching of metals in chat 
in the same manner as does hot mix asphalt, including slurry seals, 
microsurfacing, cold mix asphalt, epoxy seals and chip seals. 
Commenters did not provide data to support their assertions. The Agency 
reviewed published information regarding the binding and durability 
characteristics of these uses and found that, except for chip seals, 
they would retard the leaching of metals in the same manner as hot mix 
asphalt. To further confirm this information, we met with Department of 
Transportation officials to determine which of these applications, if 
any, do in fact encapsulate chat similarly to hot mix asphalt. Based on 
those discussions and our review of published information, the Agency's 
criteria includes the use of chat in slurry seals, microsurfacing, warm 
mix asphalt, cold mix asphalt, and epoxy seals as safe and 
environmentally protective in transportation construction projects that 
are carried out in whole, or in part, using Federal funds, but does not 
include the use of chat in chip seals. Specifically:
     Slurry seals and microsurfacing involve the application of 
a mixture of asphalt, chemical binders, petroleum liquids and aggregate 
on the top surface of roads. This ``resurfacing'' meets a number of 
needs, including repairing fine fractures in the road surface, 
extending the life of the road, and improving skid resistance. EPA 
reviewed literature on these uses and found that these uses have the 
same engineering characteristics as hot mix asphalt. EPA also met with 
the FHWA, U.S. DOT to determine if microsurfacing and slurry seals 
retard the leaching of metals in the same manner as hot mix asphalt. 
FHWA indicated that slurry seals and microsurfacing would bind metals 
in the same manner as hot mix asphalt and would result in similar 
leaching results. Based on this conclusion and our review of the 
literature, the Agency today views the use of chat in slurry seals and 
microsurfacing as safe and environmentally protective.
     As part of EPA's discussions with FHWA, we also discussed 
the ability of warm mix asphalt and cold mix asphalt to encapsulate and 
bind chat. Warm mix asphalt is a combination of asphalt, asphalt 
emulsions, paraffin or esterfied wax, and mineral additives that allow 
the materials to be worked at temperatures much lower than hot mix 
asphalt. Cold mix asphalt is a combination of asphalt, petroleum 
liquids, soaps, and other chemicals which allow the materials to be 
worked with when cold. FHWA confirmed that warm and cold mix asphalt 
would encapsulate chat in the same manner as hot mix asphalt, and thus, 
would likely result in similar leaching results. Based on Agency 
conversations with FHWA and our review of the literature, the Agency 
also views the use of chat in warm and cold mix asphalt as safe and 
environmentally protective.
     EPA also discussed the use of epoxy binders on bridge 
decks with FHWA. Commenters and one of the chat washing companies noted 
that some chat is sold to companies which mix chat with epoxy binders 
for use as an anti-skid coating for highway bridges. EPA evaluated the 
engineering durability of these epoxies and found that they are equal 
to or are more durable than asphalt. FHWA also confirmed that the use 
of epoxies would encapsulate chat equally to the binding found with 
asphalt, and thus, would result in similar leach results. Based on this 
conclusion, the Agency today views the use of chat in epoxy binders for 
anti-skid purposes as safe and environmentally protective.
    In conclusion, the use of chat in hot mix asphalt, slurry seals, 
microsurfacing, warm mix asphalt, cold mix asphalt, or epoxy seals in 
transportation construction projects funded, in whole or in part, with 
Federal funds is safe and environmentally protective. Such uses do not 
require approval from EPA prior to their use, as long as certification 
and recordkeeping requirements are met.
iii. Concrete, Flowable Fill, Granular Road Base, Stabilized Road Base 
and Chip Seals and Conditions for Use
    This rule regarding the use of chat in concrete pavement has 
changed from that presented in the April 2006 proposal and this rule 
sets additional requirements on chat used in PCC. In particular, the 
proposed rule allowed chat used as an aggregate in PCC without any 
testing or other requirements. The Agency proposed the use of chat in 
PCC based on the following data and information:
     An undated OU Surbec-Art Environmental study \7\ and a 
2000 OU study \8\ conducted the only known assessments of total metals 
content and TCLP testing of concrete matrices mixed with raw chat. The 
2000 OU results are also presented in the 2005 OU study. The results 
from those two studies are presented in the following Table:
---------------------------------------------------------------------------

    \7\ Preliminary Report on the Findings of Environmental and 
Engineering Tests Performed on Mine Residual Materials from Ottawa 
County, Oklahoma.
    \8\ Development of Holistic Remediation Alternatives for the 
Catholic 40 and Beaver Creek.

----------------------------------------------------------------------------------------------------------------
                                                         S1                    S2                    C40
                                               -----------------------------------------------------------------
                                                Total (mg/ TCLP (mg/  Total (mg/ TCLP (mg/  Total (mg/ TCLP (mg/
                                                   kg)         l)        kg)         l)        kg)         l)
----------------------------------------------------------------------------------------------------------------
Lead..........................................        178       0.92        379       0.17        150          1
Cadmium................................
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