xvEPA
United States
Environmental Protection
Agency
June 2007
EPA530-F-07-016B
www.epa.gov/osw
Tri-State Mining District - Chat
Mining Waste
Introduction
On June 5, 2007, the Environmental Protection Agency (EPA) established
mandatory criteria for the environmentally protective use of chat in transportation
projects carried out, in whole or in part, with Federal funds. To supplement this rule,
EPA Regions 6 and 7 are jointly issuing this guidance on the uses of chat that would
be consistent with that rule. In addition, EPA is offering further recommendations
on uses of chat in other contexts. The rule establishes criteria for chat that is from
the Tri-State Mining District of Ottawa County, Oklahoma, Cherokee County,
Kansas, and Jasper, Newton, Lawrence and Barry Counties in Missouri. This fact
sheet supersedes fact sheets issued by EPA Regions 6 and Region 7 in June 2002 and
February 2003, respectively.
This fact sheet serves as guidance for chat washers, vendors who use chat (chat
use), and for anyone selling chat. This guidance provides recommendations on
the use of chat that EPA believes will generally be protective. If used properly,
the environment and human health can be protected. However, improper use of
chat may increase the threat to human health and the environment. Therefore, EPA
recommends that chat be treated in accordance with the national rule and generally,
with this fact sheet. To ensure that human health and the environment will be
protected, EPA believes that the ultimate use of the material generally should not
allow people, and in particular young children, to come into direct contact with any
raw chat. In addition, EPA generally recommends that prior to use of all other mining
wastes, regardless of its lead concentration, that assessments of risk (i.e. site specific
risk assessments or the use of SPLP), similar to those in the national rule for chat, be
conducted.
Background
Historic lead and zinc mining in the Midwest was centered in two major areas:
the Tri-State area covering more than 2,500 square miles in southwestern Missouri,
southeastern Kansas, and northeastern Oklahoma and the Old Lead Belt covering
about 110 square miles in southeastern Missouri. The first recorded mining occurred
in the Old Lead Belt in about 1742. The production increased significantly in both
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the Tri-state area and the Old Lead Belt during the mid-1800s and lasted up to 1970.
Currently production still occurs in a third area, the Viburnum Trend, in southeastern
Missouri. Mining and milling of ore produced more than 500 million tons of wastes
in the Tri-State area and about 250 million tons of wastes in the Old Lead Belt. More
than 75 percent of this waste has been removed, with some portion of it used over
the years. Today, approximately 100 million tons of chat remain in the Tri-State
area. The EPA, the states of Oklahoma, Kansas and Missouri, local communities,
and private companies continue to work together in implementing and monitoring
response actions that reduce or remove potential adverse impacts posed by remaining
mine wastes contaminated with lead, zinc, cadmium, and other metals.
Chat and Tailings
Ore production consisted of crushing and grinding the rock to standard sizes and
separating the ore. Ore processing was accomplished in either a dry gravity separation
or through a wet washing or flotation separation. Dry processes produced a fine gravel
waste commonly called "chat." The wet processes resulted in the creation of tailings
ponds used to dispose of waste material after ore separation. The wastes from wet
separation are typically sand and silt size and are called "tailings." Milling produces
large chat waste piles and flat areas with tailings deposited in impoundments. Tailings
generally contain higher concentrations of heavy metals and therefore present a
higher risk to human health and the environment through direct contact. Chat
typically ranges in diameter from 1/4 to 5/8 inch. Intermingled material such as sands
measure 0.033-0.008 inches in diameter and fine tailings are less than 0.008 inches in
diameter.
Another lesser occurring type of mine waste is called development rock.
Development rock is the waste rock generated in drilling shafts to the deep mines and
therefore did not come from the major ore producing rocks. Typically, development
rock consists of large boulders and is locally known as "bullrock." Smelters also
operated historically in Kansas, Missouri, and Oklahoma; however, this fact sheet
does not address smelter related wastes.
Health Risk from Lead
When playing in lead-contaminated chat or in a home that has chat dust tracked
in from the outside, children may ingest lead when they put their hands or other dirt-
covered objects in their mouths. Children are more sensitive to the health effects of
lead than adults. Fetuses exposed to lead in the womb, because their mothers have
a lot of lead in their bodies, may be born prematurely and have lower weights at
birth. Exposure in the womb, in infancy, or in early childhood also may slow mental
development and cause lower intelligence later in childhood.
Large chat piles contaminated with lead also pose a risk to adolescents who
climb or recreate on them. Female adolescents may absorb lead from this exposure
which can be transferred to their fetuses during pregnancies later in their lives. Lead
exposure can also cause other problems in adults, such as increases in blood pressure,
anemia, and impaired nervous system or kidney function.
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By eliminating the unrestricted use of loose chat (i.e., chat that has not been
bound in concrete, asphalt, or a safe product), we can effectively reduce human
exposure to lead.
Legal Considerations
If waste material is used in a way that creates a threat to human health or the
environment, the owner of the property and the party responsible for creating the
hazardous situation could be liable for a cleanup under the CERCLA law. Because
these mine wastes often contain lead, cadmium, zinc or other metal contaminants
at levels that present a risk to both human health and the environment, using them
in situations that would allow people or ecological receptors (animals, plants, fish,
etc.) to regularly come into contact with the material could cause sufficient risks that
warrant remediation action under CERCLA. To avoid potential CERCLA liability,
EPA generally recommends that property owners, haulers, operators, and individuals
or businesses that sell, buy, or use mine waste materials which contain hazardous
constituents, use the materials in a manner that prevents exposure to humans and
other receptors, and is otherwise not detrimental to the environment.
Chat Usage Regulations and Guidlines
The following is a list of typical uses of chat that EPA regulations and RODs have
determined to be acceptable and unacceptable.
Acceptable Uses of Chat in Transportation Construction Projects
EPA has determined the following uses of chat in transportation construction
projects funded, in whole or in part, with Federal funds are not likely to present a
threat to human health and the environment:
(1) Chat used as an aggregate in: hot mix, warm mix and cold mix asphalt road
surfaces, asphalt road base, asphalt slurry seals/microsurfacing, and epoxy bridge
anti-skid surfacing.
(2) Chat used as an aggregate in: Portland cement concrete (PCC), granular road
base, stabilized road base, chip seals, and flowable fill if:
(a) the product is tested using the Synthetic Precipitation Leaching Procedure
(SPLP, EPA SW 846 Test Method 1312) and the resulting metals in the
leachate do not exceed the National Primary Drinking Water Standards
Maximum Contaminant Level (MCL) for lead of 0.015 mg/1 and cadmium of
0.005 mg/1 and the leachate also does not exceed the National Recommended
Water Quality Criteria chronic standard for zinc of 120 ug/1: or
ITitle VI of Section 6018 of the Safe, Accountable, Flexible, and Efficient Transportation Equity
Act of 2005 (HR 3 or "the Act"), amended Subtitle F of the Solid Waste Disposal Act (42 U.S.C.
6961 et seq) by adding Sec. 6006 which requires EPA to develop rules governing the use of chat in
transportation construction projects funded, in whole or in part, with Federal funds. In June 2007 U.S.
Environmental Protection Agency (EPA) issued regulations governing these uses (see XX FR XXXX).
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(b) 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 leachate will not cause an exceedance
of the National Primary Drinking Water Standards Maximum Contaminant
Level (MCL) for lead of 0.015 mg/1 and cadmium of 0.005 mg/1 in potential
drinking water sources, and the fresh water National Recommended Water
Quality Criteria for zinc of 120 ug/1 in surface waters, or
(3) The use of chat has been authorized pursuant to a state or federal response
action. State or Federal response actions are undertaken pursuant to applicable
Federal or State environmental laws and with consideration of site-specific risk
assessments.
Acceptable Non-Transportation Uses of Chat in Cement and Concrete
The Agency recommends that the non-transportation uses of chat in cement and
concrete be limited to non-residential construction projects that, on a case-by-case
basis, either:
(1) Synthetic Precipitation Leaching Procedure (SPLP, EPA SW-846 Method
1312) tests conducted on the proposed material show that concentrations in the
leachate do not exceed the National Primary Drinking Water Standards for lead
of 0.015 mg/1 and cadmium of 0.005 mg/1 and the fresh water chronic National
Recommended Water Quality Criterion for zinc of 120 ug/1; 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 leachate will not cause an exceedance of the National Primary
Drinking Water Standards Maximum Contaminant Level (MCL) for lead of 0.015
mg/1 and cadmium of 0.005 mg/1 in drinking water sources, and the National
Recommended Water Quality Criteria for zinc of 120 ug/1 in surface waters.
Other Uses of Chat that EPA Believes Will Not Generally Harm
Human Health or the Environment:
- Applications that encapsulate chat as a material for manufacturing a safe
product or as part of an industrial process (e.g., glass, glass recycling) where all
waste byproducts are properly disposed.
Chat Uses that Have Caused or Have the Potential to Cause Damage
to Human Health or the Environment:
- Use as unencapsulated surface material.
- Fill material in yards, playgrounds, parks, and ball fields, schools or daycare
centers.
2 Title VI of Section 6018 of the Safe, Accountable, Flexible, and Efficient Transportation Equity
Act of 2005 (HR 3 or "the Act"), amended Subtitle F of the Solid Waste Disposal Act (42 U.S.C. 6961
et seq) by adding Sec. 6006 which requires EPA to develop guidance on the safe use of chat in non-
transportation cement and concrete projects.
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- Playground sand.
- Vegetable gardening in locations with contaminated chat.
- 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 and environmental risk is eliminated
by engineering controls (e.g., removing the contaminated soil or capping the
contaminated soil with at least 12 inches of clean soil).
- Use of remilled asphalt roads containing chat on residential properties as fill
material or placed on residential property for the homeowner's future use.
- Use as an agricultural amendment.
- Use of chat piles for recreation (e.g., ATVs, bicycling, hiking, climbing,
sliding).
To the extent users have questions about any specific uses of chat that are not
listed above, users are encouraged to consult with EPA or the States of Oklahoma,
Kansas, and Missouri, as appropriate.
Recommended Precautions during Construction Projects
General Construction Practices: Please note that even when chat is put to
use as described above as generally acceptable, EPA recommends that care be used
to prevent a release. It is especially important to use chat in construction without
spreading it beyond the area where it is intended to be used. For example, there could
be a situation in which chat was stockpiled prior to being mixed into concrete, but
it is inadvertently spread to surrounding areas before it is added to the cement. Chat
can be spread by construction traffic, wind or rainfall runoff. Consequently, adequate
controls and monitoring are recommended to prevent spreading of contamination
during construction to include dust suppression, air monitoring to check air quality, as
needed, erosion controls, tracking of trucks spilling contaminated material off the site,
and stormwater management.
Remilled Asphalt Roads Containing Chat: EPA generally recommends that
remilled asphalt follow the process requirements developed by the National Asphalt
Pavement Association and standards established by each state's Department of
Transportation. As noted previously, asphaltic material made of remilled roads used
on residential or public use properties as fill material or placed on residential property
for the homeowner's future use raises potential health and environmental concerns.
Accordingly, such use could result in the property owner being held liable for
removal and clean up of the property.
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Utility Excavations: EPA recommends that particular care be exercised
when excavating for utilities in contaminated areas in order to avoid spreading
contamination to clean areas. When stockpiling or temporarily staging excavated
materials, EPA recommends that adequate controls (e.g., containment of excavated
soil, dust suppression, and runoff and erosion controls) are in place to prevent the
spread of contaminated soils and leachate to clean areas. Excavated contaminated
materials can generally be placed back into the excavations without posing significant
human health or environmental risks as long as a minimum clean cover is used. A
cover of six inches of clean material is normally adequate in utility right-of-ways.
In residential areas, at least 12 inches of clean fill would generally be protective.
Alternatively, excavated contaminated material could be disposed of in accordance
with applicable laws and regulations. EPA generally recommends against leaving
contaminated excavated material exposed at the surface after construction is
complete.
Best Management Practices for Chat Processing
Two methods of chat processing are in use in the Tri-State District: they are dry
screening or washing. In some instances, a combination of these two methods are
used. EPA generally believes that the Best Management Practices (BMPs) for the
management and processing of chat described below will effectively reduce the
environmental concerns. In general, BMP components include:
• Proper disposal of process water to include injection into underground mine
caverns to eliminate surface impoundments and generation of fine tailings.
Controlling process water to avoid discharge to surface water during and up to
a 25-year storm event.
Constucting berms around mill ponds or surface impoundments capable of
retaining water without seepage.
• Developing contingency measures and response plans to address releases from
source water, process water, sediment and storm water.
• Containment of stockpiles of chat to prevent spread of contaminated material.
• Controlling storm water runoff within the process areas.
Dust mitigation to minimize dust generated from the processing of chat and
on-site haul roads to include wetting, mist curtains, and foam blankets.
• Air monitoring during chat processing, as needed, to confirm air quality and
effectiveness of dust mitigation.
• Controlling releases from trucks hauling raw and/or processed chat off-site to
prevent fugitive dust and off-site tracking of contaminated soil to include covering
truck loads of chat with tarps and washing trucks prior to leaving the site and
entering public roads to prevent tracking.
• Decontamination of personnel and equipment.
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• Access controls like fences and gates.
• Developing contingency measures and response plans to address unintended
releases from source water, process water, sediment and storm water.
It is further recommended that storage and transportation of the reclaimed asphalt
pavement generally follow the BMPs for chat processing.
Owners and operators are encouraged to notify and coordinate with their state
agencies to establish and implement the BMPs for their chat processing operations.
Off-site Rule
Because multiple entities are involved with the tracking of where chat is used, the
sale of chat, and the disposal of mine waste, it is important for the public and involved
parties dealing with chat to know how EPA and other federal agencies handle wastes
from CERCLA response actions. During the Federal response action, waste that is
disposed off-site, must be sent to a facility that complies with the Off-site Rule. The
purpose of the Off-site Rule is to avoid having CERCLA wastes contribute to present
or future environmental problems by directing such wastes to management units
determined to be environmentally sound. To accomplish this objective, each region
has an Off-site Rule Coordinator who determines whether facilities are acceptable
for the receipt of CERCLA waste. EPA makes every attempt to ensure the proper
treatment and disposal of CERCLA wastes removed from a CERCLA site. As a
result, facilities that meet the criteria to receive the designated waste are used.
Certification
With the exception of chat under the jurisdiction of the U.S. Department of
Interior, Bureau of Indian Affairs (BIA), which has its own certification criteria, all
other parties involved with the sale and use of chat in transportation construction
projects funded, in whole or in part, with Federal funds shall:
(1) Submit a signed, written certification to the environmental regulatory agency
in the State where the chat is to be used within 30 days of the date of acquisition.
The certification shall contain the following:
(i) Location of origin of the chat
(ii) Amount of chat acquired; and
(iii) Certification Statement: I certify under penalty of law that the chat used in
this project will meet EPA criteria found in 40 CFR §278.3.
(2) Transfer. If the chat is sold or otherwise transferred to another party, the
acquirer shall provide a copy of the certification to the new owner of the chat.
The new owner shall submit a certification according to 40 CFR §278.4(a) (1).
The new certification supersedes all previous certifications.
(3) Recordkeeping. The acquirer of chat, and any other person that receives the
chat, will maintain a copy of the certification for three years following transmittal
to the State department(s) of the environment.
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For More Information Contact
If you would like additional information about this fact sheet or Superfund mining
sites in Kansas or Missouri, please contact EPA Region 7's toll-free number 1-800-
223-0425.
If you would like additional information about this fact sheet or Superfund mining
sites in Oklahoma, please contact EPA Region 6's toll-free number 1-800-533-3508.
For information about the final rule entitled, Criteria for the Safe and
Environmentally Protective Use of Granular Mine Tailings known as "Chat", please
contact Stephen Hoffman at 703-308-8413 or hoffman.stephen@epa.gov.
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