United States Solid Waste and EPA530-R-99-020a
Environmental Protection Emergency Response NTIS: PB99-155 822
Agency (5305W) April 1998
Response to Comments
Document: Land Disposal
Restrictions-Phase IV Final
Rule Promulgating Treatment
Standards for Metal Wastes;
Mineral Processing Secondary
Materials and Bevill Exclusion
Issues; Treatment Standards
for Hazardous Soils; and
Exclusion of Recycled Wood
Preserving Wastewaters;
Volume 1: Comments Related to Phase
III Proposed Rule (March 2, 1995)
Printed on paper that contains at least 30 percent postconsumer fiber
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List of Phase IV Land Disposal Restriction Codes,
Description, and Location by Page Number
Code
FOUN1
Description
Comments on Foundry Sand Issues
Page Number
1
Index of Commenters and Location of Comment, By Issue
UNITED STEEL WORKERS OF AMERICA
Foundry Sands 13
AMERICAN FOUNDRYMEN'S SOCIETY, INC
Foundry Sands 38
BEVERIDGE & DIAMOND, P.C.
Foundry Sands 63
CHESAPEAK SPECIALTY PRODUCTS
Foundry Sands 71
CYANOKEM
Foundry Sands 18
ENVIRONMENTAL TECHNOLOGY COUNCIL
Foundry Sands 61
GMD ENV SYSTEMS, INC
Foundry Sands 69
NIBCO, INC
Foundry Sands 20
RMT, INC
Foundry Sands 50
STEEL STRUCTURES PAINTING COUNCIL
Foundry Sands 46
TANOAK ENTERPRISES, INC
Foundry Sands 1
THE TDJ GROUP, INC
Foundry Sands 32
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Page Intentionally Blank
11
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Phase III LDR Rule: Comments and Responses
or Issues Related to Foundry Wastes
Issue: FOUN1-004 Respondent: ITS
Den: PH3P004 Extension: CBI: N
Commenter: TANOAK ENTERPRISES, INC
Comment Number: 00001
//COMM1
//RESPTTS
//SUB JFOUN1-004
THE FEDERAL REGISTER STATES ON PAGE 11731:
THE AGENCY IS AWARE OF A PRACTICE WITHIN THE FOUNDRY INDUSTRY THAT
RECYCLES FOUNDRY SAND BY THERMALLY OXIDIZING IMPURITIES. IT IS EPA'S
VIEW THAT THIS PROCESS WOULD VIOLATE THE POLICY AGAINST COMBUSTION
OF INORGANICS,....'.
IT IS RECOGNIZED THAT THE AGENCY'S CONCERN IS DIRECTED TOWARDS AN
UNCONTROLLED (AND IMPERMISSIBLE) RELEASE OF LEAD INTO THE
ENVIRONMENT. THE AGENCY ALSO RAISES CONCERN WITH RESPECT TO THE
TREATMENT OF LEAD CONTAINING SAND BY ADDITION OF IRON DUST AND
FINALLY REQUESTS ON PAGE 11732:
'COMMENTS AND DATA ARE ALSO SOLICITED ON WHETHER A TEST METHOD
OTHER THAN THE TCLP IS MORE APPROPRIATE FOR MEASURING COMPLIANCE
OF THIS WASTE.'
THIS COMMENT ADDRESSES SPECIFICALLY THE SITUATION OF FOUNDRY SAND
FROM BRASS AND BRONZE FOUNDRIES WHICH SHOWS TOXICITY
CHARACTERISTICS FOR LEAD. IT OFFERS THE FOLLOWING CONSIDERATIONS:
1 TREATMENT OF SAND IN 'HIGH TEMPERATURE' THERMAL DEVICES
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2 TREATMENT OF SAND IN AN ALTERNATIVE METHOD, USING 'LOW
TEMPERATURE' 3 CONSIDERATION OF AN ALTERNATE TESTING METHOD
1 TREATMENT OF SAND IN 'HIGH TEMPERATURE' THERMAL DEVICES
THIS AGENCY'S PROPOSAL STATS ON PAGE 11731:
'IS EPA'S VIEW THAT THIS PROCESS WOULD VIOLATE THE POLICY AGAINST
COMBUSTION OF INORGANICS,....'.
MUCH OF THE WORK CARRIED ON WITH RESPECT TO 'HIGH TEMPERATURE
PROCESSING' IS BASED ON US PATENT 4408985 OF OCT. 11, 1983 WHERE LEAD
BEARING FOUNDRY SAND WAS THERMALLY PROCESSED AND WHERE THE
FOLLOWING CLAIMS ARE MADE:
i
'(2) THE METHOD OF CLAIM 1, AND FURTHER WHEREIN THE ROASTING IS
CARRIED OUT IN AN OXYGEN ATMOSPHERE'
'(4) THE METHOD OF CLAIM 3, AND FURTHER WHEREIN THE ROASTING IS
CONDUCTED AT A TEMPERATURE OF AT LEAST 710°C
'(5) THE METHOD OF CLAIM 4, AND FURTHER WHEREIN THE ROASTING IS
CONDUCTED AT A TEMPERATURE OF APPROXIMATELY 800°C FOR A PERIOD OF
APPROXIMATELY 45 MINUTES' '(7) A SAND COMPOSITION HAVING LEAD
COMPOUNDS THEREIN, THE TOTAL LEAD COMPOUNDS BEING PRESENT IN
EXCESS OF 5 PPM BUT THE ACETIC ACID SOLUBLE LEAD COMPOUNDS BEING
PRESENT IN NO GREATER THAN 5 PPM'.
WHILE THIS PATENT REQUIRES AN OXIDIZING ATMOSPHERE AND PRESCRIBES A
MINIMUM TEMPERATURE OF 710°C, IT DOES NOT PROVIDE A MATERIAL
BALANCE WHICH LEAVES THE POSSIBILITY OF LEAD EMISSIONS VIA THE
EXHAUST GAS STREAM.
"LANGE'S HANDBOOK OF CHEMISTRY", 14TH EDITION [MCGRAW-HILL]
PROVIDES ON PAGES 3.36 AND 3.37 BOILING POINTS FOR CERTAIN LEAD OXIDES
OF 595 °C AND ALSO SUGGESTS THAT SUCH OXIDES WOULD DISSOCIATE. SINCE
THE PREVIOUSLY SUGGESTED MINIMUM TEMPERATURE, COMBINED WITH THE
REQUIREMENT FOR AN OXIDIZING ATMOSPHERE, IS SUBSTANTIALLY ABOVE
THE BOILING POINT FOR THOSE LEAD OXIDES, THIS WOULD SUGGEST STRONG
POSSIBILITY FOR THE GENERATION OF A LEAD COMPOUND VAPOR PHASE.
RESEARCH PUBLISHED IN SEPTEMBER 1992 ['DEVELOPMENT OF A STEEL-
FOUNDRY WASTE SAND RECLAMATION PROCESS', MICHIGAN TECHNOLOGICAL
UNIVERSITY, INSTITUTE OF MATERIALS PROCESSING], REPORTS ABOUT LEAD
ACCUMULATION ON THE SAND FROM A LEAD CONTAINING BINDER IN MULTI-
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CYCLE PROCESSING. HOWEVER, THE CONDITIONS IN THIS CASE WERE
DIFFERENT FROM THOSE REQUESTED IN THE BEFORE MENTIONED PATENT,
NAMELY
* THERMAL RECLAMATION WAS IN THE LABORATORY IN A LINDBERG BOX
FURNACE (PAGE 61 OF REPORT). NO INFORMATION IS PROVIDED WITH RESPECT
TO THE PROCESSING ATMOSPHERE OR EXHAUST GAS FLOW RATES.
* ALL CYCLING TESTS WERE PERFORMED AT A RECLAMATION TEMPERATURE
OF 600°C (PAGE 69 OF REPORT)
* LEACHATE VALUES IN THE RECLAIMED SAND AS HIGH AS 700 PPM WERE
DETERMINED (TABLE 80 OF REPORT). HOWEVER, IT MUST ALSO BE STATED
THAT THE PB LEACHATE VALUES FROM PROCESSING A LEAD FREE BINDER
WERE DETERMINED TO BE AS HIGH AS 39 PPM!
IF WE DISREGARD THE INCONSISTENCY JUST STATED, IT IS QUITE POSSIBLE
THAT AN ACCUMULATION OF LEAD WAS OBSERVED, KEEPING IN MIND THE
UNCERTAINTY WITH RESPECT TO THE EXISTING FURNACE ATMOSPHERE AS
WELL AS THE FACT THAT THE PROCESSING TEMPERATURE WAS VERY CLOSE TO
(AND POSSIBLY BELOW) THE BOILING TEMPERATURE OF THE LOWEST BOILING
LEAD OXIDES.
IF WE ASSUME THAT THE GENERALLY APPLIED THERMAL PROCESSING
CONDITIONS WOULD BE AMENABLE TO VAPOR GENERATION, WE MUST NOW
CONSIDER WHAT THE CONSEQUENCES OF SUCH VAPOR GENERATION MIGHT BE.
FIRST, THERMAL 'RECLAIMERS' ARE SUBJECT TO THE EMISSION LIMITATIONS
SPECIFIED BY THE CLEAN AIR ACT 1990 (CAA 1990). TITLE III DOES LIST 'LEAD
COMPOUNDS'. THUS, ANY VAPORS WHICH MAY BE GENERATED BY THE HIGH
TEMPERATURE PROCESSING MUST BE CONTROLLED AND CANNOT BE LEGALLY
RELEASED TO THE ENVIRONMENT.
LEAD EMISSIONS FROM THERMAL PROCESSES ARE NOTHING NEW AND WE
FIND FOR EXAMPLE IN "STANDARD HANDBOOK OF HAZARDOUS WASTE
TREATMENT AND DISPOSAL" [MCGRAW-HILL] ON PAGE 8.63 THE FOLLOWING
STATEMENTS:
'AT CEMENT-KILN TEMPERATURES, MATERIALS WHICH ARE ORDINARILY
CONSIDERED NONVOLATILE NOT ONLY MELT, BUT BOIL'.
BUT THIS SAME ARTICLE WHICH REPORTS ABOUT THE COMBUSTION OF LEAD
CONTAINING MATERIALS IN A CEMENT KILN THEN CONTINUES TO EXPLAIN:
'EXHAUST GASES EXITING THE KILN STACK ARE TYPICALLY AT TEMPERATURES
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BETWEEN 150°C (300°F) AND 250°C (480°F). CONSEQUENTLY, POTASSIUM
CHLORIDE, LEAD OXIDE, OR OTHER MATERIALS VOLATILIZED IN THE BURNING
ZONE WILL CONDENSE ONTO PARTICLE SURFACES RATHER THAN BEING
EMITTED WITH THE STACK GASES'.
THIS SITUATION IS COMPARABLE TO THE SITUATION IN THERMAL
RECLAIMERS' IN THE FOUNDRY INDUSTRY AND SUGGESTS THAT, EVEN IF LEAD
COMPOUND VAPORS WOULD BE EMITTED FROM THE HIGH TEMPERATURE ZONE,
SUCH LEAD COMPOUNDS WOULD NOT BE RELEASED TO THE ENVIRONMENT AS
VAPORS BUT WILL LIKELY CONDENSE ONTO OTHER PARTICULATE SURFACES
(OR MAY CONDENSE INTO LEAD OXIDE PARTICLES). HOWEVER, THE CAA 1990
CLEARLY IMPOSES LIMITS WITH RESPECT TO MAXIMUM PERMISSIBLE LEAD
COMPOUND EMISSIONS.
BEYOND THESE REGULATIONS, WE ALREADY HAVE THE REGULATION UNDER
40 CFR PART 60, SUBPART UUU WHICH APPLIES TO ALL 'CALCINERS' PROCESSING
'INDUSTRIAL SAND1 (I.E. THERMAL RECLAIMERS AS USED IN FOUNDRIES). THIS
REGULATION APPLIES TO ALL INSTALLATIONS AFTER APRIL 23, 1986. THE
OPERATION OF A CONTINUOUS OPACITY MONITORING SYSTEM (COM) AS
MANDATED UNDER THIS RULE WILL CONTROL THE EMISSION LIMITS FOR
PARTICULATE MATTER - AND IT IS IN THIS FORM THAT THE LEAD WOULD BE
EMITTED AFTER THE POLLUTION ABATEMENT SYSTEM IF NOT RETAINED BY
SUCH SYSTEM. THUS, WE HAVE TWO PIECES OF LEGISLATION WHICH GOVERN
AND CONTROL THE OPERATION OF THERMAL RECLAIMERS AND WE CAN
THEREFORE ASSUME THAT UNCONTROLLED RELEASE OF LEAD IN ANY FORM TO
THE ENVIRONMENT IS POSITIVELY AVOIDED (PREDICATED UPON COMPLIANCE
WITH EXISTING LEGISLATION).
HOWEVER, THERE IS ALSO ANOTHER TECHNICALLY POSSIBLE FORM FOR
'LEAD CONTROL' WHICH IS PRODUCTION PROVEN AND WHICH SHALL BE
DESCRIBED IN THE FOLLOWING CHAPTER 2.
2 TREATMENT OF SAND IN AN ALTERNATIVE METHOD, USING 'LOW
TEMPERATURE'
THE DEVICE USED IN THIS PROCESS IS COVERED IN US PATENT 4,681,267 OF
JULY 21, 1987 AND US PATENT 4,709,862 OF DECEMBER 1,1987. IN CONTRAST TO
THE AFOREMENTIONED 'HIGH TEMPERATURE1 APPROACH, THIS SYSTEM USES
THERMAL ENERGY ONLY TO ESSENTIALLY DRY THE FOUNDRY SAND AND
EMBRITTLE ANY RESIDUAL BINDER SO THAT IT CAN BE PROPERLY REMOVED BY
MEANS OF ATTRITION. THERMAL PROCESSING AND ATTRITION OCCUR
SIMULTANEOUSLY IN THE SAME PROCESSING VESSEL. THE ATTRITION
PRODUCT, WHICH NOW CONTAINS THE CONTAMINANT IN CONCENTRATED
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FORM IS COLLECTED IN AN APPROPRIATE DEVICE (CLOTH FILTER OR SIMILAR).
THE FACT THAT THE CONTAMINANT, FOR EXAMPLE LEAD, IS NOW
CONCENTRATED IN A MUCH SMALLER VOLUME PERMITS TO CONSIDER METAL
EXTRACTION FROM THIS PROCESS STREAM OR, IF STILL JUDGED
UNECONOMICAL, PERMITS TO TREAT A MUCH SMALLER STREAM TO ACHIEVE
COMPLIANCE WITH ENVIRONMENTAL REGULATIONS.
GIVEN THE FACT THAT ALREADY TODAY SUBSTANTIAL QUANTITIES OF
PROCESS BY-PRODUCTS FROM BRASS AND BRONZE FOUNDRIES ARE BEING
CHANNELED TOWARDS METAL RECOVERY SUCH AS GRINDINGS, TRIMMINGS,
AND DROSS, MAKES METAL RECOVERY ALSO FROM THIS SMALL STREAM FROM
SAND PROCESSING A REALISTIC POSSIBILITY.
PERFORMANCE OF 'LOW TEMPERATURE1 SYSTEM (ENCL. A)
ENCL. Al SHOWS HOW LEACHABLE LEAD CAN BE REDUCED IN SPENT SAND
FROM A BRASS FOUNDRY FROM 24 PPM TO 3.1 PPM BY LEAD REMOVAL, USING
COMBINED THERMAL (DRYING) PLUS ATTRITION AS PER US PATENTS 4,681,267
AND 4,709,862. LEAD REDUCTION TO EVEN LOWER RESIDUAL LEVELS IS
POSSIBLY BY SIMPLE EXTENSION OF THE PROCESSING TIME. THE PROCESSING
TEMPERATURE APPLIED IN DRYING IS CLEARLY BELOW THE BOILING POINT OF
VARIOUS LEAD OXIDES. IT IS ALSO BELOW THEIR MELTING POINTS AND THE
GENERATION OF LEAD COMPOUND VAPORS IS THEREFORE ELIMINATED.
HOWEVER, WITH THE MUCH LOWER PROCESSING TEMPERATURES, THE
POTENTIAL EMISSION OF HYDROCARBONS MUST BE CONSIDERED.
CONTRARY TO FLUID BEDS OR ROTARY KILNS, THIS PROCESS IS A BATCH
PROCESS. A UNIT WITH CAPACITY 1 T/H IS SHOWN IN ENCL. A2. TESTING WAS
PERFORMED BY MEASURING EXHAUST GAS TEMPERATURE AT POINT "A", I.E.
IMMEDIATELY AT THE EXIT FROM THE PROCESS VESSEL AND WITHOUT ANY
DILUTION. SAMPLES OF THE "PRODUCT OF COMBUSTION" [POC] WERE TAKEN
AT POINT "B", THAT IS FROM THE EXHAUST GAS DUCT LEADING FROM THE
PROCESSING VESSEL AND BEFORE THE GAS STREAM ENTERS EITHER CYCLONE
OR CLOTH FILTER. THUS, THE TESTED STREAM REPRESENTS AN UNDILUTED
POC SAMPLE.
THE GRAPH AS PER ENCL. A3 SHOWS THE TEMPERATURE RANGES FOR BOTH,
SAND AND POC, FROM A TEST WHICH WAS PERFORMED OVER TEN (10)
OPERATING HOURS, REPRESENTING 120 BATCHES.
THE POC TEMPERATURE IS LOW ENOUGH THAT NO FURTHER DILUTION IS
REQUIRED PRIOR TO ENTERING A CLOTH FILTER. ENCL. A4 PROVIDES AN
EVALUATION FROM THIS TEST AND DOCUMENTS THAT TOTAL EXHAUST GAS
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FLOW IN THIS SYSTEM IS ON THE ORDER OF 15 LBS PER MINUTE OR, BASED ON
THE PROCESSING CAPACITY OF 1 T/H, ON THE ORDER OF APPROX. 1,000 LBS/H
POC FOR EACH TON OF SAND PROCESSED. THUS, THE POC TO SAND RATIO IS ON
THE ORDER OF 0.5 VS. 5 (AND MORE) FOR FLUID BED OR ROTARY KILN SYSTEMS.
THIS MEANS THAT POLLUTION ABATEMENT EQUIPMENT CAN BE HELD TO VERY
SMALL SIZES. IT ALSO DOCUMENTS THAT, IF HYDROCARBON EMISSIONS FROM
INCOMPLETE COMBUSTION (DUE TO THE LOW PROCESSING TEMPERATURE)
WOULD BE A PROBLEM, THE GAS FLOW RATE SUBJECT TO 'POST TREATMENT' IN
THE FORM OF AN AFTER BURNER WOULD BE VERY SMALL AND THE ENERGY
REQUIRED FOR SUCH PROCESS WOULD BE ON THE ORDER OF 340,000 BTU PER
TON OF SAND PROCESSED.
THUS, IF WE COMBINE ENERGY REQUIREMENT FOR SAND DRYING AND AFTER
BURNER, WE WOULD HAVE A TOTAL ENERGY CONSUMPTION OF 700,000 BTU PER
TON OF SAND PROCESSED. THIS IS, AT A MINIMUM, 30% LOWER THAN HIGH
TEMPERATURE PROCESSING AND IN ALL LIKELIHOOD 50% OR MORE LOWER! A
PROPER EVALUATION ABOUT ENERGY CONSUMPTION CAN ONLY BE
ESTABLISHED IF WE DOCUMENT ALL ENERGY STREAMS AS PER ENCL. A5.
THERE ARE NO KNOWN PUBLICATIONS WHERE THIS HAS BEEN DONE.
HOWEVER, FROM NUMEROUS PAPERS IT CAN BE GLEANED THAT WHILE ENERGY
CONSUMPTION RATES OF 106 BTU PER TON OF SAND ARE FREQUENTLY QUOTED,
ACTUAL CONSUMPTION RATES IN OPERATING SYSTEMS ARE SIGNIFICANTLY
HIGHER. THE AUTHOR OF THE REPORT 'SAND RECLAMATION CONCEPT
DEFINITION STUDY' (GAS RESEARCH INSTITUTE, OCTOBER 1990) STATES ON
PAGE 51:
'4. HEAT BALANCES ON MANY UNITS DO NOT APPEAR TO BE REALISTIC '
THE QUESTION STILL REMAINS: DO WE NEED POST TREATMENT OF POC? IN A
SECOND TEST, THE FOLLOWING DATA WAS ESTABLISHED:
POC COMPOSITION: 4.1% CO2; 14.1% O2; 0% CO [USING AN ORSAT APPARATUS].
THIS INDICATES A REASONABLE COMBUSTION EFFICIENCY. O2 LEVELS ARE
ACTUALLY LOWER THAN THOSE REPORTED FROM FLUID BED SYSTEMS WITH
THEIR HIGH PROCESSING TEMPERATURE. THIS DOES NOT SURPRISE BECAUSE
TURBULENCE IN THIS EQUIPMENT IS MUCH HIGHER AND THE TEMPERATURE
GRADIENT DUE TO DIRECT FLAME IMPINGEMENT AT VERY LOW EXCESS AIR
RATES MUCH HIGHER. THUS, THE GOOD EMISSION VALUES REPORTED FROM
FLUID BED SYSTEMS WHICH ARE GENERALLY MEASURED AT THE CLEAN AIR
EXIT ARE THE RESULT OF DILUTION. IF THE CONTAMINANT LEVEL WOULD BE
EXPRESSED AT A CONSTANT O2 DILUENT RATE, FLUID BEDS AND ROTARY KILNS
WOULD HAVE CLEARLY HIGHER EMISSION RATES.
THE POC ANALYSIS PERFORMED IN ONE SPECIFIC TEST WHEN SAMPLING AT
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POINT "B" AS SHOWN IN ENCL. A2 RESULTED IN A HYDROCARBON EMISSION OF
34 MG/M3, EXPRESSED AS METHANE EQUIVALENT. THIS WAS EQUIVALENT TO
6.6 LBS METHANE PER 106 LBS PROCESSED SAND. AS WAS SHOWN IN ENCL. A4,
106 LBS SAND CORRESPONDED TO 500,000 LBS POC OR, IN OTHER WORDS,
HYDROCARBON EMISSIONS (EXPRESSED AS METHANE EQUIVALENT)
AMOUNTED TO 13 LBS PER 106 LBS POC.
IT MUST BE RECALLED THAT THIS CONTAMINANT LEVEL WAS MEASURED IN
THE UNDILUTED POC STREAM PRIOR TO DUST FILTER. IT IS SAFE TO ASSUME
THAT A PORTION OF THIS CONTAMINANT WOULD BE ADSORBED ONTO THE
DUST PARTICLES COLLECTED IN A CLOTH FILTER AND CONSEQUENTLY,
HYDROCARBON CONTAMINANTS DISCHARGED TO THE ENVIRONMENT CAN BE
ESTIMATED TO BE LESS THAN 6 LBS METHANE EQUIVALENT PER 1,000,000 LBS
POC.
(
WE MUST NOW CONSIDER WHAT THE EFFECT WOULD BE IF AN EFFORT
WOULD BE MADE TO FURTHER REDUCE THOSE CONTAMINANTS BY WAY OF
AFTER BURNER. THE ENERGY REQUIRED FOR POST TREATMENT OF POC IS
GIVEN IN ENCL. A4 AS 340,000 BTU PER TON OF SAND PROCESSED. IF WE
EMPLOYED A THERMAL OXIDIZER FOR THIS APPLICATION, WE WOULD
GENERATE FROM THE USE OF PROPANE AN ADDITIONAL LEVEL OF APPROX. 51
LBS CO2 PER TON OF SAND OR FROM THE USE OF NATURAL GAS 47.5 LBS CO2
PER TON OF SAND. THUS, POC POST TREATMENT WOULD GENERATE ON THE
ORDER OF 25,000 LBS CO2 IN AN EFFORT TO ELIMINATE 6 TO 10 LBS
HYDROCARBON CONTAMINANT (AS METHANE EQUIVALENT). THE
JUSTIFICATION FOR THIS WOULD HAVE TO BE QUESTIONED.
HOWEVER, IT MUST BE STRESSED THAT THE BEFORE STATED NUMBERS NEED
TO BE CONSIDERED WITH SOME CAUTION. THE POC TO SAND RATIO OF UNDER 1
FOR THIS TYPE SYSTEM VS. 5 AND MORE FOR FLUID BEDS AND ROTARY KILNS
CAN BE TAKEN FOR GRANTED FOR ALL APPLICATIONS. HOWEVER, THE 'WASTE
STREAMS', BOTH SOLIDS AND GASES, WILL VARY WITH APPLICATION.
SOLIDS MAY BE AS LOW AS 3-4% IN SOME CASES (HIGH QUALITY SANDS IN
'CHEMICALLY BONDED' APPLICATIONS) BUT COULD EASILY REACH 15% AND
MORE IF THE PROCESSED SAND WOULD HAVE HIGH CLAY LEVELS (OR OTHER
FINES WHICH MAY BE ADDED FOR SPECIFIC TECHNOLOGICAL REASONS).
THE GENERATION OF HYDROCARBON CONTAMINANTS DEPENDS ON THE
CHEMICAL COMPOSITION OF THE BINDER USED. SOME (SUCH A SHELL RESIN)
WILL GENERATE VERY LITTLE CONTAMINANT SINCE THE COMPOUNDS ARE
QUITE HEAT RESISTANT. OTHERS, WITH HIGHER LEVELS OF SOLVENTS, MAY
GENERATE MORE. AT ANY RATE: THE PROCESSING AT TEMPERATURES OF
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APPROX. 400 °F WILL ALWAYS GUARANTEE THAT THE MAJORITY OF THE
CONTAMINANT IS REMOVED AS SOLID WASTE AND NOT AS POC. IF POST
TREATMENT OF POC WOULD BE REQUIRED, THIS COULD BE ACCOMPLISHED AT
LOWER COST THAN IN ANY OTHER PROCESSING SYSTEM DUE TO THE INHERENT
LOW POC TO SAND RATIO.
REFERENCE WAS MADE EARLIER TO A REPORT FROM MICHIGAN
TECHNOLOGICAL UNIVERSITY WHERE A LEAD CONTAINING BINDER RESULTED
IN LEAD BUILD-UP AND ULTIMATELY LEACHATE TOXIC SAND DUE TO AN
ACCUMULATION OF LEAD. IN ANOTHER MICHIGAN FOUNDRY, USING THIS SAME
TYPE OF BINDER, THE TECHNOLOGY DESCRIBED IN THIS SECTION WAS
IMPLEMENTED AND THE SAND NEVER EXCEEDED A LEAD LEACHATE VALUE OF
1 PPM. THE MICHIGAN DEPARTMENT OF NATURAL RESOURCES REPORTED
ABOUT THIS INSTALLATION WITH THEIR CASE STUDY #9303 OF NOVEMBER 1993
(AVAILABLE FROM OFFICE OF WASTE REDUCTION SERVICES, ENVIRONMENTAL
SERVICES DIVISION, DEPARTMENTS OF COMMERCE AND NATURAL RESOURCES,
PHONE (517)335-1178.
3 CONSIDERATION OF AN ALTERNATE TESTING METHOD
THE "STANDARD HANDBOOK OF HAZARDOUS WASTE TREATMENT AND
DISPOSAL" [MCGRAW-HILL] PRESENTS IN FIG. 8.5.2 ON PAGE 8.69 THE LEACHING
CHARACTERISTICS OF LEAD AS A FUNCTION OF PH. IT DOCUMENTS THAT
SOLUBILITY OF LEAD INCREASES WITH BOTH HIGH AND LOW PH VALUES. THIS
CERTAINLY MUST CAUSE US TO QUESTION THE PRESENT TCLP TEST WITH ONLY
ONE TESTING POINT AT PH 5. ALSO, THIS FIGURE PRESENTS DATA FROM
SAMPLES WITH DIFFERENT LEAD MASS CONTENTS AND INDICATES THAT THE
LEAD LEACHATE VALUES DO INCREASE WITH INCREASING LEAD MASS
CONTENTS. THIS LATTER STATEMENT IS IN CONTRAST TO FINDINGS IN THE US
FOUNDRY INDUSTRY.
IN 1980 A STUDY WAS CONDUCTED BY EPA AND DATA WAS SHARED WITH THE
UNIVERSITY OF WISCONSIN IN MADISON WHICH INVESTIGATED LEACHATE
BEHAVIOR FROM LEAD BEARING FOUNDRY WASTES. THE FULL INVESTIGATION
IS CONTAINED IN THE 1981 TRANSACTIONS OF THE AMERICAN FOUNDRYMEN'S
SOCIETY, PAGES 767 TO 786. ONE OF THE IMPORTANT FINDINGS WAS (ITEM 5 OF
CONCLUSIONS):
THERE WAS BASICALLY NO RELATIONSHIP BETWEEN THE PERCENTAGE OF
CADMIUM OR LEAD RELEASED IN THE EP TEST AND THE CONCENTRATION OF
THAT METAL IN THE WASTE'.
THUS, A MASS DETERMINATION OF LEAD IN THE FOUNDRY WASTE WOULD
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NOT SERVE AS A SIMPLER METHOD TO DETERMINE POTENTIAL
ENVIRONMENTAL RELEASES OF THIS SUBSTANCE.
THE FACT THAT THE INTERRELATIONS WITH RESPECT TO MIGRATION OF
LEAD (OR OTHER METALS) VIA LEACHATE ARE QUITE COMPLICATED ARE ALSO
CONFIRMED IN THE 1993 ANNUAL REPORT OF THE GERMAN ENVIRONMENTAL
AUTHORITY ['UMWELT BUNDESAMT1]. THIS REPORT COMMENTS ON PAGES
280/281 EXTENSIVELY ON THIS TEST. IT IS CLEARLY STATED THAT THE 'DANGER
POTENTIAL1 IS NOT PRIMARILY A FUNCTION OF THE MASS CONTENT OF THE
CONTAMINANT IN A WASTE STREAM BUT IS SIGNIFICANTLY INFLUENCED BY ITS
'MOBILITY1. A NUMBER OF DIFFERENT (PROPOSED) TEST APPROACHES ARE
DESCRIBED WHICH, AMONGST OTHERS, AIM AT BETTER PREDICTING LONG
TERM STABILITY OF POTENTIALLY DANGEROUS WASTE CONSTITUENTS. ONE
ASPECT OF GREAT IMPORTANCE IS THAT THE LEACHATE TEST ACCORDING TO
DIN 38414-S4 IS PERFORMED WITH DISTILLED WATER AND NOT WITH ACETIC
ACID. THIS DIFFERENT LEACH MEDIA WOULD GREATLY CHANGE THE RESULTS
OF THE LEACHATE TEST.
REFERRING BACK TO THE BEFORE MENTIONED 1981 STUDY PUBLISHED IN THE
AFS TRANSACTIONS, WE FIND UNDER CONCLUSIONS:
'3. THE EXTRACTION OF CADMIUM AND LEAD WAS HIGHLY DEPENDENT ON THE
PH OF THE SOLUTION. USING THE EP TEST PROCEDURE, BUT USING DISTILLED
WATER AS THE EXTRACTION MEDIA INSTEAD OF ACETIC ACID, THE CUPOLA
DUSTS OR SLUDGES FROM ONE FOUNDRY WERE FOUND TO BE EP TOXIC WITH
RESPECT TO CADMIUM. NO SAMPLES WERE TOXIC WITH RESPECT TO
CHROMIUM OR LEAD '.
THESE REMARKS ARE NOT MEANT TO SUGGEST THAT WE SHOULD FOLLOW
THE APPROACH PRACTICED IN GERMANY WITHOUT CAREFUL CONSIDERATION
OF ALL RAMIFICATIONS. HOWEVER, IT SHOULD BE HIGHLIGHTED THAT A
COUNTRY SUCH AS GERMANY THAT IS CERTAINLY CONCERNED ABOUT
ENVIRONMENTAL SAFETY IS APPLYING A STANDARD WHICH PLACES A MUCH
LESS ONEROUS BURDEN ON ITS INDUSTRY WHICH COMPETES HEAD ON WITH
NORTH AMERICAN COMPANIES - AND OBVIOUSLY WITHOUT SACRIFICING
ENVIRONMENTAL SAFETY.
CERTAINLY, IN THE ABSENCE OF SUBSTANTIATING DATA, NO DECISIONS CAN
(OR SHOULD) BE MADE. HOWEVER, VALUABLE DOCUMENTATION ALREADY
EXISTS.
THE UNIVERSITY OF MICHIGAN-DEARBORN CONDUCTED EXTENSIVE STUDIES
WITH RESPECT TO THE LEACHATE BEHAVIOR OF SANDS FROM BRASS AND
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BRONZE FOUNDRIES. A NUMBER OF PAPERS WERE PUBLISHED ON THIS SUBJECT
IN THE EARLY EIGHTIES AND ONE PAPER, PUBLISHED IN THE 1987
TRANSACTIONS OF THE AMERICAN FOUNDRYMEN'S SOCIETY, IS APPENDED AS
ENCL. B TO THIS COMMENT.
THE AUTHORS POINT OUT THAT THE LOGIC FOR SUGGESTING ACETIC ACID
LEACHING IS PREDICATED UPON THE ASSUMPTION THAT THE SAND WOULD BE
MIXED WITH TRASH AND GARBAGE IN A MUNICIPAL LANDFILL AND THAT
ACETIC ACID MIGHT BE GENERATED AS A DECOMPOSITION PRODUCT OF THE
COMMINGLED ORGANIC WASTE (PAGE 712). THE AUTHORS ALSO STATE (PAGE
712):
THAT IS TO SAY, THE LEACHABILITY IS NOT ONLY A FUNCTION OF THE PH BUT
IS ALSO RELATED TO THE AMOUNT OF ACETATE ION SINCE ITS PRESENCE IS
SOLELY DEPENDENT UPON THE ACID ADDITION'.'
THE AUTHORS THEN PROCEED TO SUGGEST (PAGE 715) THAT A MORE LIKELY
SCENARIO MIGHT BE THE EXPOSURE OF DEPOSITED WASTE TO SULFURIC AND
NITRIC ACID FROM ACID RAIN. A TEST WAS THEREFORE CONDUCTED WITH 'AN
ARTIFICIAL ACID RAIN'. CONCLUSIONS REACHED FROM THIS TEST WERE:
'IN ALL CASES THE ACID RAIN LEACHES LESS LEAD THAN THAT FOUND FROM
THE EP TOXICITY TEST. THE MOST SENSITIVE LEAD FORM TO SYNTHETIC ACID
RAIN LEACHING WAS PBO. HOWEVER, ONLY 16.4% OF THE LEAD WAS
EXTRACTED BY THE ACID RAIN WHEN COMPARED TO THE EP TOXICITY TEST'.
'SINCE THE PH OF ACID RAIN VARIES IN DIFFERENT PARTS OF THE COUNTRY, A
TEST AT PH OF 3.0 HAS ALSO BEEN CONDUCTED FOR THE CDA 83600 ALLOY. THE
SAME VALUE OF 6 PPM LEAD HAS BEEN OBTAINED AT BOTH 3.0 AND 5.0 PH
LEVELS'.
THESE DATA SUGGEST THAT A MONOFILL CONTAINING ONLY FOUNDRY WASTE
STREAMS MAY NOT LEACH SIGNIFICANT LEAD EVEN WHEN EXPOSED TO ACID
RAIN'.
FIG. 8 (PAGE 716) OF THIS PAPER SHOWS COMPARISONS OF 'ACID RAIN' VS.
'STANDARD' LEACHING AND SUGGESTS THAT SANDS MIGHT INDEED BE
CLASSIFIED AS NON-HAZARDOUS UNDER THIS TESTING PROCEDURE, USING
'ARTIFICIAL ACID RAIN' IN STEAD OF THE ACIDS NOW USED.
BASED ON THESE FACTS IT IS SUGGESTED THAT FOUNDRY WASTES BEING
DEPOSITED IN MONOFILLS SHOULD BE EVALUATED USING A LEACHING MEDIA
SUCH AS THE 'ACID RAIN' GENERATED IN THIS STUDY SINCE THE PRESENCE OF
10
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ACETIC ACID CAN VIRTUALLY BE RULED OUT. THIS WOULD BE AN
INTERMEDIATE SOLUTION.
IN THE LONGER TERM, A MORE CAREFUL INVESTIGATION MIGHT BE CARRIED
ON TO EVALUATE THE LEACHATE PROCEDURES NOW APPLIED (AND UNDER
INVESTIGATION) IN OTHER INDUSTRIALIZED COUNTRIES WHICH OBVIOUSLY
RENDER QUITE DIFFERENT RESULTS FROM THE APPROACH TAKEN IN THE US
AND PLACE A MUCH LESS COSTLY BURDEN ON INDUSTRY. THIS APPEARS TO BE
THE CASE WITHOUT JEOPARDIZING THE SAFETY OF THE PUBLIC. IT WOULD
CERTAINLY BE SUBJECT TO SOME SERIOUS DEBATE WHETHER WE CAN ASSUME
THAT A HIGHLY INDUSTRIALIZED COUNTRY (AND DENSELY POPULATED) SUCH
AS GERMANY WOULD DELIBERATELY PERMIT 'LAX STANDARDS' SUCH AS USE
OF DISTILLED WATER AS A LEACHING MEDIA IF IT WOULD NOT GUARANTEE
PROPER SAFEGUARDS FOR THE HEALTH OF ITS CITIZENS.
//ENDC1
RESPONSE
[The commenter expressed the following opinions concerning EPA's position with
respect to treatment of foundry sand:
1. The commenter questioned EPA's concern regarding uncontrolled and impermissible
releases of lead into the atmosphere as a result of treatment of foundry sands in high
temperature thermal devices. The commenter stated that the Clean Air Act (CAA) 1990
emission limitations for thermal reclaimers, and 40 CFR Part 60, Subpart UUU
(requirement for continuous opacity monitoring for particulates) "govern and control the
operation of thermal reclaimers" and therefore, the commenter assumes that uncontrolled
releases of lead will be avoided.
2. The commenter asserted that low temperature thermal processing is viable for treatment
of foundry sand and presented various technical points to illustrate that hydrocarbon
emissions could be readily controlled.
3. The commenter suggested that EPA use an alternative testing method to demonstrate
leaching potential of metals such as a leach test using sulfuric or nitric acid to
demonstrate the acid rain scenario, rather than the simulation of acetic acid generation via
the EP toxicity test using acetic acid.
With respect to the uncontrolled release of lead into the atmosphere, the Agency remains
concerned about the volatilization of lead and the potential for releases of lead to the atmosphere
during thermal treatment or reclamation of foundry sand. In the Phase III LDR rule the Agency
11
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stated that combustion of inorganics violates EPA's policy unless the combusted waste contains
toxic organics or has significant organic composition.
Regarding the commenter's assertion that low temperature thermal processing is viable
for treatment of foundry sand, the Agency notes that the treatment standards finalized in today's
rulemaking are concentration-based and not technology-based. Therefore, any type of treatment
technology can be used to meet the treatment standards provided the treatment unit, if required,
is properly permitted. EPA also notes that to the extent the process involves solely the recovery
of metals (as defined in 266.100), metal recovery devices are not presently subject to RCRA
regulation. This assumes that the device involved is an industrial furnace.
Regarding the comment on test methods, EPA disagrees with the commenter's assertion
that an alternative testing method in lieu of the TCLP should be allowed for assessing the
potential leaching of iron-treated foundry sand. The Agency has established the TCLP as the
required method for determining whether a waste will be considered toxicity characteristic
hazardous (40 CFR 261.24(a)). EPA's determination of the use of the TCLP was finalized on
March 29,1990 (55 FR 11798). This issue is not being reopened in this rulemaking. However,
EPA reviewed the suitability for testing the leachability of lead in foundry sand and continues to
believe that TCLP testing is appropriate for determining whether the waste meets the treatment
standards. This issue is discussed in the Technical Memorandum entitled "Iron Dust Treatment
of Lead-Bearing Foundry Sand," dated September 15, 1995, and can be found in the
Administrative Record for this rulemaking.
12
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Issue: FOUN1-005 Respondent: ITS
Den: PH3P005 Extension: CBI: N
Commenter: UNITED STEELWORKERS OF AMERICA
Comment Number: 00001
//COMM1
//RESPTTS
//SUB JFOUN1-005
PROBLEMS WITH TCLP TEST
ADDITION OF IRON TO D008 WASTE SAND MAY MASK THE PRESENCE OF
LEAD IN TWO WAYS. FIRST, IRON IS MORE EASILY OXIDIZED THAN LEAD.
UNDER THE CONDITIONS OF THE TCLP TEST, IRON MAY BE PREFERENTIALLY
LEACHED OUT INTO SOLUTION, LEAVING THE LEAD IN AN INSOLUBLE, AND
THEREFORE UNDETECTABLE, STATE. THE GIBBS FREE ENERGIES FOR THE
RELEVANT REACTIONS AT T=298K ARE:
PB + 1/2 O2 PBO "G = -28.9 KCAL
2 FE + 3/2 O2 FE2O3 "G = -353.9 KCAL
WHILE THE NEGATIVE FREE ENERGIES INDICATE THAT BOTH REACTION ARE
THERMODYNAMICALLY FAVORABLE, IN FACT ONLY THE OXIDATION OF IRON
PROCEEDS AT A MEASURABLE RATE AT ROOM TEMPERATURE. (THIS IS WHY
IRON OBJECT RUST WITHIN DAYS IF LEFT OUTSIDE, BUT LEAD PIPES IN ROMAN
BATHS ARE STILL IN SERVICE). UNDER THE MILDLY ACIDIC CONDITIONS AND
SHORT DURATION OF THE TCLP TEST, WE EXPECT THAT THE IRON OXIDATION
WILL PROCEED MUCH MORE QUICKLY THAN THE LEAD OXIDATION, WITH THE
RESULT THAT LESS LEAD WILL BE LEACHED OUT OF THE SAMPLE THAN IF
EXCESS IRON WERE NOT PRESENT.
A SECOND PROBLEM WITH THE PRESENCE OF IRON IN THE TCLP TEST IS
SPECTRAL INTERFERENCE WITH THE ANALYSIS OF LEAD. THE INSTRUMENTAL
TECHNIQUES MOST LIKELY TO BE USED TO ANALYZE LEAD ARE GRAPHITE
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FURNACE ATOMIC ABSORPTION (GFAA) AND INDUCTIVELY COUPLED PLASMA
(ICP). THE WAVELENGTHS RECOMMENDED FOR LEAD IN EPA METHOD 239.1
(LEAD BY GFAA) ARE 283.3 NM, 217.0 MM, AND 261.4 NM. THE CONTRACT
LABORATORY PROGRAM ICP METHOD FOR LEAD (BASED ON EPA METHOD 200.7)
RECOMMENDS A WAVELENGTH OF 220.353. IRON HAS A LARGE NUMBER OF
SPECTRAL LINES THAT MIGHT OVERLAP THE RECOMMENDED WAVELENGTHS
FOR LEAD (SEE CRC HANDBOOK OF CHEMISTRY AND PHYSICS, 75TH EDITION, PP.
10-44 THROUGH 10-48). A LARGE AMOUNT OF IRON IN A SAMPLE BEING
ANALYZED FOR LEAD COULD RESULT IN A POSITIVE INTERFERENCE, AND A
RAISED DETECTION LIMIT FOR LEAD.
HAZARDS OF INADEQUATELY TREATED D008 WASTE SAND
WHEN D008 WATER IS "TREATED" BY ADDITION OF IRON, THE CHEMICAL
AND PHYSICAL FORM OF THE WASTE IS NOT CHANGED. AT MOST, THE
PROPENSITY OF THE LEAD TO LEACH INTO GROUND WATER IS REDUCED. BUT
GROUND WATER IS NOT THE MOST IMPORTANT POTENTIAL ROUTE OF
EXPOSURE TO LEAD IN SOLID WASTE. AS EPA HAS RECOGNIZED, "GENERALLY,"
THE GROUND WATER PATHWAY WILL NOT POSE A SIGNIFICANT RISK..." FROM
LEAD IN SURFICIAL SOILS. [REVISED INTERIM SOIL LEAD GUIDANCE FOR
CERCLA SITES AND RCRA CORRECTIVE ACTION FACILITIES, JULY 14, 1994].
INHALATION OF DUST AND DIRECT INGESTION OF SOIL, ESPECIALLY BY
CHILDREN, ARE FAR MORE IMPORTANT ROUTES OF EXPOSURE TO LEAD IN THE
GROUND. TREATED D008 WASTES, ESPECIALLY CONTAMINATED SOILS, COULD
BE USED AS FILL, ROAD BASE, ETC., MAKING SUCH EXPOSURE ROUTES HIGHLY
PLAUSIBLE.
THE TCLP DOES NOT MEASURE THE RISKS POSED BY DIRECT INGESTION OR
DUST INHALATION, BUT ONLY THE PROPENSITY TO CONTAMINATE
GROUND WATER. CONSEQUENTLY, TREATMENT METHODS THAT SPECIFICALLY
ALTER TCLP RESULTS WITHOUT REDUCING THE INGESTION AND INHALATION
HAZARDS ARE NOT PROTECTIVE OF PUBLIC HEALTH /I. TREATMENT METHODS
FOR D008, AND OTHER LEAD-BEARING WASTES SUCH AS K061 AND K069, SHOULD
BE ACCEPTED ONLY IF THEY CHANGE THE CHEMICAL OR PHYSICAL FORM OF
THE WASTE IN A WAY THAT SUBSTANTIALLY REDUCES THE HAZARD FROM
DUST INHALATION AND DIRECT INGESTION.
PHOSPHATE TREATMENTS FOR D008
THE USE OF PHOSPHATE-BASED ADDITIVES AS TREATMENT FOR D008
WASTES RAISES THE SAME QUESTIONS AS THE IRON ADDITIVES AND SHOULD BE
ADDRESSED IN THE SAME RULE. SUCH TREATMENT HAS BEEN PROPOSED FOR
LEAD-CONTAMINATED SOILS THAT ARE CLASSIFIED AS D008 WASTES AT THE
14
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REVERE SMELTING AND REFINING SITE IN WALKILL, NEW YORK, WHICH IS
SUBJECT TO REMEDIATION UNDER RCRA CORRECTIVE ACTION. THE SAME
TREATMENT METHOD HAS BEEN PROPOSED FOR SIMILAR MATERIALS AT THE
AVANTI SITE IN INDIANAPOLIS, INDIANA, WHICH IS UNDERGOING A CERCLA
REMOVAL ACTION. THE COMPANIES UNDERTAKING BOTH OF THESE CLEAN-UPS
ARE SUBSIDIARIES OF RSR CORPORATION. OUR UNION REPRESENTS EMPLOYEES
AT RSR'S INDIANAPOLIS PLANT AND IS ON STRIKE AGAINST A RELATED
COMPANY, BAYOU STEEL CORPORATION, IN LAPLACE, LOUISIANA.
A COPY OF THE PROPOSED CORRECTIVE MEASURES PLAN FOR THE WALKILL,
NEW YORK SITE IS ENCLOSED. THE TREATMENT INVOLVES THE ADDITION OF A
PHOSPHATE FIXATION AGENT AND BUFFER, IN A POWDER FORM, TO LEAD-
CONTAMINATE SOIL, FOLLOWED BY THOROUGH MIXING. ORDINARILY, WATER
WOULD BE ADDED TO FACILITATE THIS REACTION, BUT THE WALKILL
PROPOSAL NOTES ONLY THAT "MOISTURE WILL BE ADDED AS NEEDED FOR
DUST SUPPRESSION." THE FIXATION AGENT/BUFFER AND CONTAMINATED SOIL
ARE APPARENTLY MIXED IN A RELATIVELY DRY STATE.
CURRENT RESEARCH ON THE USE OF PHOSPHATE ROCK TO REMEDIATE
LEAD CONTAMINATED SOIL/2 INDICATES THAT THIS TREATMENT IS NOT YET A
MATURE TECHNOLOGY. COLUMN LEACHING STUDIES IN THE LABORATORY
INDICATE THAT SOLUBLE LEAD IS REDUCED IN CONTAMINATED SOILS TREATED
WITH PHOSPHATE. HOWEVER, THE REDUCTION IN SOLUBLE LEAD CAN BE AS
SMALL AS 38%. THE IMPORTANT FACTORS THAT GOVERN THE FORMULATION OF
INSOLUBLE LEAD MINERALS IN SUCH LABORATORY STUDIES (SUCH AS THE
PHOSPHATE ROCK-TO-CONTAMINATED SOIL RATIO), ARE AS YET IMPERFECTLY
UNDERSTOOD. THE BEHAVIOR OF LEAD IN CONTAMINATED SOIL TREATED IN
SITU WITH PHOSPHATES CANNOT YET BE PREDICTED WITH CONFIDENCE.
CONTROL SAMPLES (LEAD CONTAMINATED SOIL WITH NO PHOSPHATE ADDED)
IN THE CITED STUDIES ALSO SHOWED DECREASES IN SOLUBLE LEAD OVER
TIME. THIS RAISES QUESTIONS ABOUT THE ABILITY OF THE LABORATORY
STUDIES TO REPRESENT REAL ENVIRONMENTAL CONDITIONS, AND WHETHER
THE DECREASE IN LEAD CONCENTRATION IS COMPLETELY ATTRIBUTABLE TO
THE PHOSPHATE TREATMENT.
OF COURSE, THE WHOLE DISCUSSION OF REDUCING LEAD LEACHING INTO
THE GROUND OR SURFACE WATERS FROM CONTAMINATED SOILS DOES NOT
ADDRESS THE MOST LIKELY EXPOSURE SCENARIOS. THE DUST INHALATION
AND DIRECT INGESTION HAZARDS WOULD REMAIN EVEN AFTER PHOSPHATE
TREATMENT. EVEN IF PHOSPHATE TREATMENT EFFECTIVELY REDUCES LEAD
LEACHING UNDER REAL ENVIRONMENTAL CONDITIONS (WHICH HAS NOT BEEN
ADEQUATELY DEMONSTRATED), THERE IS NO EVIDENCE OF LONG-TERM
EFFECTIVENESS. IT MUST BE DEMONSTRATED THAT THE TREATED SOILS POSE
15
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NO HAZARD FROM INHALATION OR INGESTION.
//ENDC1
RESPONSE
[The commenter made the following comments:
1. asserted that the addition of iron dust to D008 waste foundry sand may mask the presence
of lead, and thus the D008 waste may be inadequately treated;
2. asserted that the TCLP analysis does not measure the risks posed by dust inhalation or
ingestion; and
3. expressed skepticism about the effectiveness of phosphate treatment for D008 waste and
had similar concerns with respect to phosphate treatment as with the addition of iron to
D008 wastes.
The Agency agrees with the commenter that the addition of iron dust to D008 waste sand may
mask the presence of leachable lead. The Agency reviewed several comments and research
studies for and against the "impermissible dilution" designation for iron treatment of
characteristic metal wastes, and has concluded that addition of iron metal, in the form of fines,
filings, or dust fails to provide long-term treatment for lead characteristic metal wastes,
regardless of their origin, and constitutes a form of "impermissible dilution." EPA notes that
RCRA requires that the TCLP analysis for determination of TC hazardousness be determined at
the point of waste generation (55 FR 11830 March 29, 1990). Further, EPA notes that the TCLP
testing by the foundry industry to demonstrate whether the waste is in fact TC hazardous (and
hence, require treatment) is typically performed after the addition of the iron dust. The argument
that the addition of iron dust is part of the process generating the waste is not valid.
As shown by the field studies conducted by Dr. Drexler and Dr. Kendall, the addition of
iron filing results in no modification of the physical, chemical, or biological character of the
waste. The addition of irons filing facilitates the adsorption of soluble lead on to the iron surface.
However, once the iron surfaces oxidize, the ability of the additive to scavenge soluble metals is
diminished,which is a dilution effect - See Drexler Report, pp. 14, 16, 18. Therefore, this is a
reversible reaction and is not permanent. In addition, adsorption alone is not a reliable method of
permanently immobilizing lead. Therefore, in the long-term, the migration of hazardous
constituents is not retarded and thus, the requirements of RCRA 3004(m) are not fulfilled.
The type of treatment that only masks the test but does not actually reduce hazardous
constituent mobility to any meaningful extent is not a type of waste management that can be said
to minimize threats to human health and the environment. Therefore, the Agency, in today's
final Phase IV rule, is promulgating regulatory language that confirms that the practice of iron
addition as the sole form of treatment for lead in characteristic metal wastes is a type of
impermissible dilution.
16
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The Agency is also codifying this determination by amending 40 CFR 268.3 to read as
follows:
40 CFR 268
§ 268.3 Dilution prohibited as a substitute for treatment
* * *
(d) It is a form of impermissible dilution, and therefore prohibited, to add iron filings or other
metallic forms of iron to lead-containing hazardous wastes in order to achieve any land disposal
restriction treatment standard for lead. Lead-containing wastes include D008 wastes (wastes
exhibiting a characteristic due to the presence of lead), all characteristic wastes containing lead as
an underlying hazardous constituent, listed wastes containing lead as a regulated constituent, and
hazardous media containing any of the aforementioned lead-containing wastes.
* * *
!
In response to the commenter's remark about the TCLP test, EPA has established the
TCLP as the required method for determining whether a waste is a toxicity characteristic
hazardous waste (40 CFR 261.24 (a)). The TCLP test is designed to reflect the potential for the
waste to leach at levels that pose a threat to human health and the environment. EPA's
determination of the appropriateness of the use of TCLP was finalized on March 29, 1990 (55 FR
11798). This issue is not being reopened in this rulemaking. However, EPA reviewed the
suitability for testing the leachability of lead in foundry sand and continues to believe that TCLP
testing is appropriate for determining the characteristic of hazardousness for metal-bearing
wastes. This issue is discussed in the Technical Memorandum entitled "Iron Dust Treatment of
Lead-Bearing Foundry Sand," dated September 15, 1995, and can be found in the Administrative
Record for this rulemaking. The Agency agrees with the commenter that the TCLP test does not
measure the risks posed by direct ingestion. However, TCLP test is appropriate for testing
materials placed in a landfill, since the principal threat to the environment is the leaching of toxic
materials.
The Agency acknowledges the commenter's points relating to the phosphate treatment of
foundry sands. However, because the Agency has inadequate data with respect to phosphate
treatment, the Agency is not addressing the issue of phosphate-based additives as treatment for
D008 wastes in this rulemaking. However, the Agency notes that any type of treatment
including phosphate treatment of foundry sands, that temporarily masks the test methods and
does not result in long-term treatment would be considered impermissible dilution.
17
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Issue: FOUN1-009 Respondent: TTS
Den: PH3P009 Extension: CBI: N
Commenter. CYANOKEM
Comment Number: 00003
//COMM3
//RESPTTS
//SUBJFOUN1-009
CLASSIFICATION OF ADDITION OF IRON DUST AS IMPERMISSIBLE DILUTION
CYANOKEM SUPPORTS EPA'S PROPOSAL TO CLASSIFY AS IMPERMISSIBLE
DILUTION THE USE OF IRON DUST OR FILINGS AS STABILIZING AGENTS FOR
CERTAIN CHARACTERISTIC WASTES. CYANOKEM AGREES FULLY WITH EPA'S
DISCUSSION IN THE PREAMBLE AT PAGE 11731 AND ADDS FURTHER THAT NO
CHEMICAL REACTION OR POZZOLANIC REACTION IS POSSIBLE FROM IRON DUST
OR FILINGS. THEREFORE MICROENCAPSULATION OR STABILIZATION IS NOT
TAKING PLACE, ONLY DILUTION. THERE IS NO CHEMISTRY THAT CAN BE
CONTRIVED TO JUSTIFY THAT METALS SUCH AS LEAD ARE BEING
PERMANENTLY BOUND IN A NON-LEACHABLE MATRIX, WHEN USING IRON DUST
OR FILINGS AS A STABILIZING AGENT.
CYANOKEM HAS ENCOUNTERED MANY CASES WHERE GENERATORS HAVE
AVOIDED TREATMENT COSTS BY ADDING IRON TO THEIR METAL AND CYANIDE
BEARING WASTE STREAMS. THIS PROVIDES THE SHORT TERM ABILITY TO FOOL
THE TESTS FOR BOTH AMENABLE CYANIDE AND LEACHABLE METALS. EPA'S
ADOPTION OF A TOTAL CYANIDE TREATMENT STANDARD HAS ESSENTIALLY
SOLVED THE ISSUE OF MASKING EFFECTIVE TREATMENT OF CYANIDE USING
IRON, BUT THE ISSUE OF METALS STILL REMAINS. CYANOKEM WELCOMES THIS
PROHIBITION ON USE OF IRON DUST AND FILINGS, AND AGREES WITH EPA THAT
IT WOULD PROMOTE MORE TREATMENT OF TOXIC METAL BEARING WASTES.
//ENDC3
RESPONSE
f
18
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The Agency thanks the commenter for supporting EPA's position on the issue of
designating the addition of iron dust to D008 waste sand as impermissible dilution. The Agency
reviewed several comments (from Phase III and Phase IV NOD A) and research studies for and
against the "impermeable dilution" designation for iron treatment of characteristic lead wastes,
and has concluded that addition of iron metal, in the form of fines, filings, or dust fails to
provide long-term treatment for D008 characteristic metal waste, regardless of their origin, and
constitutes a form of "impermissible dilution." Therefore, the Agency, in today's final Phase
IV rule, is promulgating regulatory language that designates addition of iron filings to
characteristic lead wastes as "impermissible dilution."
19
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Issue: FOUN1-010 Respondent: TTS
Den: PH3P010 Extension: CBI: N
Commenter: NIBCO, INC
Comment Number: 00001
//COMM1
//RESPTTS
//SUBJFOUN1-010
i
LONG TERM TREATMENT
TO VERIFY LONG TERM TREATMENT. TWO OPTIONS WERE AVAILABLE. THE
FIRST WAS THE LABORATORY APPROACH OF PERFORMING THE TCLP OR THE
PREVIOUS EP-TOXICITY TEST, EACH INTENDED TO PREDICT THE WORST CASE
SCENARIO FOR 100 YEARS OF STORAGE IN AN IMPROPERLY DESIGNED AND OR
MANAGED MUNICIPAL LANDFILL. MATERIALS STABILIZED WITH METALLIC
IRON HAVE CONSISTENTLY PASSED THESE TESTS.
TO FURTHER THIS WORST CASE APPROACH, MULTIPLE LEACHING PROCEDURES
HAVE BEEN PERFORMED UNDER SEVERAL PROTOCOLS. ONE PROCEDURE WAS
PERFORMED ON EXTRACTS USING SW-846 METHOD 1390 IN WHICH THE WASTE
SAMPLES WERE EXTRACTED ACCORDING TO THE EXTRACTION PROCEDURE
TOXICITY TEST, FOLLOWED BY 4 ADDITIONAL SYNTHETIC RAIN EXTRACTIONS.
THE RESULTS OF THESE TESTS CAN BE FOUND IN APPENDIX A SECOND
PROCEDURE SERIALLY SUBJECTED A SAMPLE OF WASTE SAND TO 5 SUCCESSIVE
TCLP TESTS. THE CONCLUSION REACHED ON PAGE TWO (2) OF THE REPORT
WHICH IS ATTACHED IN APPENDIX F STATES THAT " THE SAND WAS STILL NON-
HAZARDOUS AFTER FIVE SUCCESSIVE TOXICITY TESTS, USING THE MORE
RIGOROUS TEST PROCEDURE."
AN ADDITIONAL STUDY WAS PERFORMED BY TURPIN, P. D., AND B. E. DUDZIK.
1987 "CASE STUDIES IN SUCCESSFUL FOUNDRY WASTE TREATMENT." --
AMERICAN FOUNDRYMEN'S SOCIETY (AFS) TRANSACTIONS, 95:695-698. THE AFS
STUDY WAS REFERENCED ON PAGE 38 OF THE BATTELLE REPORT OF FEBRUARY
22, 1994. WHILE THE BATTELLE REPORT APPEARS TO BE MUCH OF THE BASIS
FOR THE PUBLICATION IN THE FEDERAL REGISTER OF MARCH 2, 1995, THE
RESULTS OF THE AFS STUDY DO NOT SUPPORT THE CONCLUSIONS REACHED BY
20
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THE AGENCY. IN THE CITED AFS STUDY, "THE LEAD LEACHING FROM THE
WASTE WAS CONTROLLED OVER NINE ACIDIC LEACHING STEPS IN THE EP
MULTIPLE EXTRACTION PROCEDURE."
THE SECOND OPTION THAT CAN BE USED IS EXISTING FIELD STUDIES THAT
HAVE BEEN CONDUCTED ON FOUNDRY SAND LANDFILLS THAT HAVE BEEN
STABILIZED WITH IRON DUST; LANDFILLS THAT HAVE BEEN IN EXISTENCE
SINCE THE MID 80'S (THE INCEPTION OF METALLIC IRON STABILIZATION). ONE
SUCH CHARACTERIZATION WAS PERFORMED ON FOUNDRY WASTE DISPOSED AT
THE NACOGDOCHES MUNICIPAL LANDFILL. THE CHARACTERIZATION WAS
PREPARED BY RMT INC. - MADISON, WISCONSIN FORNIBCO INC.,
NACOGDOCHES TEXAS IN DECEMBER OF 1993. THE CONCLUSION REACHED IN
THIS CHARACTERIZATION WAS THAT THE WASTE DISPOSED OF IN THIS
LANDFILL IS NOT A HAZARDOUS WASTE. A COPY OF THE BODY OF THIS REPORT
IS ENCLOSED IN APPENDIX G. THIS REPORT WAS'SUBMITTED TO THE USEPA
REGION VL IN DECEMBER OF 1993.
MASKING OF THE TCLP RESULTS
IT HAS BEEN SUGGESTED BY THE EPA THAT THE LEAD IN THE TCLP TEST IS
BEING MASKED BY THE PRESENCE OF IRON OR OTHER TREATMENT
CHEMISTRIES IT APPEARS THAT THE SUPPORTING DOCUMENTATION IS A
LETTER WRITTEN TO MR. JOHN GAUTHIER OF US EPA, REGION 17 OFFICE OF
SOLID WASTE DATED SEPTEMBER 8, 1992 FROM DATANET ENGINEERING, INC. OF
BALTIMORE, MD. THE LETTER STATES THAT "ACCORDING TO GAIL HANSEN OF
EPA OFFICE OF SOLID WASTE, THE PRESENCE OF IRON MAKES THE TCLP QUITE
IMPRACTICAL AS ESTABLISHED BY SPIKED SAMPLES HAVING EXCEEDINGLY
POOR RECOVERY RATES." A COPY OF THIS LETTER IS INCLUDED IN APPENDIX K.
THIS STATEMENT BY MS. HANSEN HAS NOT BEEN SUBSTANTIATED AND NO TEST
RESULTS WERE USED TO CONFIRM THE SUPPOSED STATEMENT. THE
JUSTIFICATION FOR THE CLAIM THAT THE IRON DUST IS MASKING THE TCLP
TEST IS THE IMPLICATION THAT WHEN THE SAMPLE IS SPIKED WITH A KNOWN
AMOUNT OF DISSOLVED LEAD,(MATRIX SPIKE) THE RECOVERY RATE IS
EXTREMELY LOW. ENCLOSED IN APPENDIX J ARE SAMPLES OF TCLP TEST
RESULTS PERFORMED ON FOUNDRY SAND WITH IRON PRESENT. ALL OF THESE
TESTS WERE RUN WITH MATRIX SPIKE ADDITIONS. THE RECOVERY RATES ON
THE MATRIX SPIKE RANGED FROM 90°~O TO 105%. THESE EXCELLENT
RECOVERY RATES CONTRADICT THE SUGGESTION THAT THE IRON MASKS THE
ANALYTICAL DATA. AT NO TIME DURING NLBCO'S 10 YEARS OF EXPERIENCE
WITH EP-TOXICITY OR TCLP TESTING WAS THERE ANY EVIDENCE OF POOR
RECOVERY RATES ON MATRIX SPIKE ADDITIONS. THE ONLY APPARENT
POTENTIAL FOR POOR RECOVERY WOULD OCCUR IF THE LAB SPIKED THE
SAMPLE PREMATURELY (BEFORE FILTRATION) IN WHICH CASE THE TREATMENT
21
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CHEMISTRY WOULD LIKELY CAUSE THE LEAD TO BE PRECIPITATED.
THE AGENCY STATED THAT "... THE ADDITION OF IRON HAS BEEN
DEMONSTRATED TO RESULT IN FALSE NEGATIVES FOR LEAD..." WHILE THE
SUGGESTION OF FALSE NEGATIVES APPEARS IN THE AFOREMENTIONED LETTER
OF SEPTEMBER 8, 1992, NO SUPPORTING LAB DATA ACCOMPANIED THE LETTER.
IN ADDITION, NOWHERE IN THE BATTELLE REPORT, OR ANY OTHER SUPPORT
DOCUMENTATION HAS THIS DEMONSTRATION BEEN CONFIRMED. A PROPERLY
PERFORMED TCLP TEST BY A COMPETENT LAB WILL YIELD ACCURATE DATA.
ENCLOSED IN APPENDIX L ARE COPIES OF TEST RESULTS PERFORMED BY THE US
EPA HOUSTON BRANCH. MOST OF THESE TESTS WERE PERFORMED ON FOUNDRY
WASTE STREAMS THAT HAD BEEN STABILIZED USING METALLIC IRON. THESE
LAB REPORTS DO NOT SPECIFY ANY QA/QC DATA, WHICH WOULD SUGGEST
THAT QA/QC PROCEDURES WERE PERFORMED WITH NO QUESTIONABLE
RESULTS. ANY OTHER CONCLUSION WOULD SUGGEST THAT THESE TESTS WERE
IMPROPERLY CONDUCTED AND ARE THUS NOT ACCEPTABLE TESTS.
IT APPEARS THAT THE ORIGINAL PURPOSE OF THE TCLP TEST, IE. TO PREDICT
POTENTIAL WORST CASE SCENARIO OF LEACHABILITY IN A MISMANAGED
MUNICIPAL SOLID WASTE LANDFILL DURING THE NEXT 100 YEARS, HAS BEEN
FORGOTTEN. THE ACETIC ACID IN THE TEST SIMULATES LANDFILL CONDITIONS
TO WHICH THE WASTE FOUNDRY SAND WOULD BE SUBJECTED IN A MUNICIPAL
WASTE LANDFILL. THE ADDITION OF IRON DUST (OR ANY OTHER APPROPRIATE
CHEMISTRY) EFFECTIVELY PREVENTS THE LEAD IN THE LANDFILL FROM
LEACHING EVEN IN THE PRESENCE OF ACETIC ACID, AS IS EVIDENCED BY THE
RESULTS OF THE EXISTING TCLP TEST.
WEAK BONDS NOT LIKELY TO BE PERMANENT
PAGE 11731 STATES THAT "..THE AGENCY BELIEVES THAT THIS 'STABILIZATION'
IS TEMPORARY, BASED UPON THE NATURE OF THE COMPLEXING. IN FACT, A
REPORT PREPARED BY EPA ON IRON CHEMISTRY IN LEAD CONTAMINATED
MATERIALS (FEB. 22, 1994), WHICH SPECIFICALLY ADDRESSED THIS ISSUE,
FOUND THAT IRON LEAD BONDS ARE WEAK, ADSORPTIVE SURFACE BONDS, AND
THEREFORE NOT LIKELY TO BE PERMANENT." THE REPORT IN QUESTION IS THE
BATTELLE REPORT OF JANUARY 1994 WHICH WAS SUBMITTED IN AN
INTERAGENCY MEMO ON FEBRUARY 22, 1994. A COPY OF THIS REPORT IS
INCLUDED IN APPENDIX M.
IN ADDITION TO STABILIZATION THROUGH THE DEVELOPMENT OF SURFACE
BONDS, IRON REACTS IN A LANDFILL SITUATION IN MUCH THE SAME WAY THAT
ZINC ACTS IN GALVANIZED STEEL. THE PRESENCE OF METALLIC IRON PREVENTS
22
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LEAD FROM LEACHING THROUGH A REDOX REACTION. NO CHEMICAL REACTION
NEEDS TO TAKE PLACE UNTIL THE LEACHING CONDITIONS ARISE AT WHICH
TIME THE PRESENCE OF IRON WILL EFFECTIVELY PREVENT LEAD FROM
LEACHING.
THE CONCLUSION REACHED BY THE AGENCY DISREGARDED THE CONCLUSIONS
REACHED IN THE BATTELLC REPORT. THE FOLLOWING ARE DIRECT
QUOTATIONS FROM THE REPORT WHICH CONTRADICT THE AGENCY'S BELIEFS.
"THE ATTRACTIVE FORCE OPERATING BETWEEN THE ADSORBED SPECIES ON
THE ADSORBENT IS RELATIVELY WEAK, BEING ON THE SAME ORDER AS VAN
DER WALLS FORCES."... "HOWEVER, LONG-TERM STABILITY OF THIS SITUATION
IS UNKNOWN." ALTHOUGH THE BATTELLE REPORT STATES THAT THE
ADSORPTIVE FORCES ARE RELATIVELY WEAK THE REPORT DID NOT REACH THE
SAME CONCLUSION AS THE AGENCY THAT THE BONDS ARE "THEREFORE NOT
LIKELY TO BE PERMANENT." THE AGENCY'S CONCLUSION ALSO NEGLECTED TO
CONSIDER THE ADDITIONAL SURFACE PROCESS DISCUSSED ON PAGE 18 OF THE
BATTELLE REPORT "IMMOBILIZATION OCCURS BY TWO SURFACE PROCESSES,
ADSORPTION AND LATTICE SUBSTITUTION (HEM, 1977)."
BESIDES THE SURFACE PROCESSES, THE BATTELLE REPORT ALSO DISCUSSES
THE EFFECTIVENESS OF THE FE-PB REDOX COUPLE (PAGE 92). "TABLE 7 SHOWS
THE STANDARD STATE ELECTRICAL AND GIBBS FREE ENERGY CHANGES FOR
THE REACTIONS WHICH DESCRIBE THE REDUCTION OF PB(II) TO PB(O) IN PURE
WATER AND WHEN ACETATE IS PRESENT. IN THE ABSENCE OF ACETATE,
REDUCTION OF PB(II) BY IRON METAL IS STRONGLY FAVORED..." THIS WOULD
BE THE SITUATION IN A MONOFILL OR NEARLY ANY LAND DISPOSAL WITH THE
EXCEPTION OF A MUNICIPAL LANDFILL WHERE THE ACETATE IS MORE LIKELY
TO BE PRESENT. THE BATTELLE REPORT GOES ON TO SAY THAT "IN GENERAL,
REDUCTION OF PB(II) IS LESS STRONGLY FAVORED WHEN ACETATE IS PRESENT,
BUT THE REACTION WILL STILL PROCEED IN THE DIRECTION OF LEAD
REDUCTION." THE BATTELLE REPORT CONFIRMS THAT LEAD REDUCTION IS
LIKELY TO OCCUR, CONTRARY TO THE "BELIEFS" OF THE AGENCY. THE
BATTELLE REPORT CONTINUES ON PAGE 99 TO CONCLUDE THAT "THE
EQUILIBRIUM PHASES SHOWN IN FIGURES 5 THROUGH 8 ARE CONSISTENT WITH
LEAD SOLUBILITY REDUCTION BY EITHER A REDOX COUPLE MECHANISM OR
SORPTION ON FE(OH)3." THE BATTELLE REPORT REACHED NO CONCLUSIONS AS
TO THE LONG TERM STABILITY OF THE IRON STABILIZATION, BUT DID SUGGEST
AN ADDITIONAL STUDY TO ELIMINATE DATA GAPS. THESE SUGGESTIONS WERE
APPARENTLY OVERLOOKED BY THE AGENCY IN AN ATTEMPT TO REACH A
CONCLUSION WITHOUT THE BENEFIT OF THE FACTS OR SCIENTIFIC EVIDENCE.
IMPERMISSIBLE DILUTION
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IN ITS PUBLICATION IN THE FEDERAL REGISTER OF MARCH 9. 1995, THE AGENCY
PROPOSED TO CLARIFY THAT THE ADDITION OF IRON DUST IS 'IMPERMISSIBLE
DILUTION'. THIS INTERPRETATION OF THE WORD DILUTION IS TOTALLY
CONTRARY TO SCIENCE AND THE ENGLISH LANGUAGE. THE DEFINITION OF
DILUTION AS FOUND IN 'CHAMBERS DICTIONARY OF SCIENCE AND
TECHNOLOGY' IS AS FOLLOWS: "DILUTION (1) DECREASE IN CONCENTRATION" IF
THE TREATMENT WERE TO BE BASED ON DILUTION A TEN PERCENT ADDITION
OF IRON DUST SHOULD YIELD A TEN PERCENT REDUCTION OF THE TOXICITY
CHARACTERISTIC. IN PRACTICE, TESTING HAS PROVEN THAT MATERIALS WITH
A TCLP CHARACTERISTIC FOR LEAD AS HIGH AS 1000 MG/L BEFORE IRON
ADDITION, YIELDS A TCLP FOR LEAD OF LESS THAN I MG/L WITH AS LITTLE AS L
0% IRON DUST ADDITION IT SHOULD BE OBVIOUS, TO EVEN THE MOST CASUAL
OBSERVER, THAT SOME CHEMICAL MECHANISM OTHER THAN SIMPLE DILUTION
IS OCCURRING.
i
IN DEFINING THE ADDITION OF 10% IRON DUST AS DILUTION. THE AGENCY IS
REACTING CONTRARY TO IT'S ACCEPTED TREATMENT TECHNOLOGY USING
LIME OR CEMENT KILN DUST (CKD). THESE TECHNOLOGIES REQUIRE AS MUCH
AS 30°/O ADDITIONS TO BE EFFECTIVE AND WOULD MORE LIKELY BE
CANDIDATES FOR THE DESIGNATION AS DILUTION. OF THE TWO
TECHNOLOGIES, IRON DUST STABILIZATION NOT ONLY PROVIDES ACCEPTABLE
TREATMENT, BUT MINIMIZES THE RESULTANT VOLUME OF THE WASTE
DISPOSED.
INTERSTITIAL WATER WOULD LIKELY ACIDIFY
THE FOLLOWING PARAGRAPH IS ANOTHER EXAMPLE OF AN ASSUMPTION BEING
MADE WITHOUT SCIENTIFIC BASIS. THE ASSUMPTION WAS SUBSEQUENTLY
USED TO JUMP TO THE WRONG CONCLUSION. THE FOLLOWING PARAGRAPH IS
CITED FROM THE MARCH 2,1995 FEDERAL REGISTER. "FURTHERMORE, AS THIS
IRON-RICH MIXTURE IS EXPOSED TO MOISTURE AND OXIDATIVE CONDITIONS
OVER TIME, INTERSTITIAL WATER WOULD LIKELY ACIDIFY, WHICH WOULD
POTENTIALLY REVERSE ANY TEMPORARY STABILIZATION, AS WELL AS
INCREASE THE LECHABILITY OF THE LEAD FROM THE FOUNDRY SAND."
NOWHERE IS THE ISSUE OF ACID FORMATION, CAUSED BY THE PRESENCE OF
IRON IN LANDFILLS, MENTIONED IN THE BACKGROUND DOCUMENTATION AND
IS CONTRARY TO ACTUAL EXPERIENCE. ACID FORMATION ASSOCIATED WITH
IRON COMES FROM HYDROLYSIS OF THE FERRIC IRON OR FROM THE OXIDATION
OF FERROUS TO FERRIC IRON. AS EVIDENCED IN THE BATTELLE REPORT,
STABILIZATION WITH METALLIC IRON CREATES REDUCING CONDITIONS IN
WHICH IRON WOULD NOT BE OXIDIZED TO THE FERROUS TO FERRIC IRON. IN
ADDITION, EXPERIENCE WITH THE TCLP TEST SHOWS THAT IRON NEUTRALIZES
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THE ACETIC ACID (AS MAY BE EXPECTED TO BE FOUND IN A MUNICIPAL
LANDFILL) AND RAISES THE PH RATHER THAN LOWERING IT AS SUGGESTED IN
THE AGENCY'S CONCLUSION.
IN PRACTICE THE NATURAL BUFFERING CAPABILITIES OF FOUNDRY SAND,
CAUSED BY THE CLAYS AND NATURAL BINDERS, HAS A TENDENCY TO
STABILIZE THE PH IN THE NEUTRAL TO SLIGHTLY BASIC RANGE.
ALTERNATIVE TESTING PROCEDURES
BASED ON SUPPORTING DATA THAT THE RECOVERY RATES FOR SPIKED
SAMPLES ARE WELL WITHIN ACCEPTABLE RANGES THERE IS NO EVIDENCE
THAT THE TCLP TEST RESULTS ARE MASKED. IN FACT IT CONFIRMS THAT THE
IRON IS DOING AN ACCEPTABLE JOB OF PREVENTING THE LEAD FROM
LEACHING. THE TCLP WAS DESIGNED TO PREDICT WORST CASE SCENARIO OF
MISMANAGED MUNICIPAL LANDFILL DISPOSAL AND ALTHOUGH IT IS
EXTREMELY AGGRESSIVE IT APPEARS TO BE AN ACCEPTABLE TEST METHOD
FOR DISPOSAL IN A MUNICIPAL SOLID WASTE LANDFILL.
WASTE FOUNDRY SAND IS COMMONLY DISPOSED OF IN A MONOFILL WHERE
ACETIC ACID IS NOT LIKELY TO BE PRESENT. PERHAPS EITHER A DISTILLED
WATER LEACHING PROCEDURE OR A SYNTHETIC ACID RAIN LEACHING
PROCEDURE, WHICH MORE CLOSELY SIMULATES IN-SITU CONDITIONS. WOULD
BE MORE APPROPRIATE. TO HELP SUBSTANTIATE THIS RECOMMENDATION,
TEST RESULTS PERFORMED ON A LEAD BEARING, SLUDGE FROM A STORM
WATER RETENTION BASIN ARE ENCLOSED. THE TEST RESULTS SHOW TCLP LEAD
TO BE 4L.9 MG/L, WHILE ALTERNATIVE LEACHING METHODS SUCH AS THE
STATE OF INDIANA LEACHING METHOD USING DE-LONIZED LEACHATE FLUID
YIELDED <0.01 MG/L, THE SULFURIC ACID LEACHING PROCEDURE YIELDED <0.1
MG/L AND THE LEACHATE PROCEDURE USING RAINWATER YIELDED
LEACHABLE LEAD AT 0.918 MG/L. I HOSE TESTS WERE ALL PERFORMED ON A
SAMPLE THAT CONTAINED 1880 MG/L OF TOTAL LEAD. A COPY OF THESE LAB
RESULTS IS INCLUDED IN APPENDIX N. THE ABOVE DATA SUPPORT THE CLAIM
THAT THE TCLP IS NOT APPROPRIATE FAR ANY DISPOSAL METHOD OTHER THAN
A MUNICIPAL SOLID WASTE LANDFILL. EXPERIENCE HAS SHOWN THAT IT IS
ONLY THE AGGRESSIVE NATURE OF ACETIC ACID WHICH CAUSES THE LEAD TO
LEACH. IN ANY OTHER DISPOSAL SCENARIO, A DISTILLED WATER OR SYNTHETIC
RAINWATER LEACHATE TEST WOULD BE MORE APPROPRIATE.
AS FURTHER PROOF OF THE IMMOBILITY OF LEAD IN FOUNDRY SAND,
ESPECIALLY IN MONOFILLS, MONITORING WELL DATA FROM A GWQAP AT THE
NIBCO NACOGDOCHES SITE IS PROVIDED IN APPENDIX H. PRIOR TO THE
HAZARDOUS WASTE REGULATIONS, WASTE FOUNDRY SAND WAS
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ACCUMULATED IN ON-SITE SURFACE IMPOUNDMENTS AND LATER DRIED AND
DISPOSED OF IN AN ON-SITE LANDFILL. THESE PONDS WERE ACTIVE FOR A
TWENTY-FIVE TO THIRTY YEAR PERIOD, INITIALLY WITHOUT TREATMENT WITH
IRON DUST. SUBSEQUENT TO THE HAZARDOUS WASTE REGULATIONS, PROCESS
MODIFICATIONS WERE INSTALLED TO INTRODUCE IRON DUST INTO THE
MATERIAL PRIOR TO GENERATION AS A WASTE. AS PART OF CLOSURE OF THESE
SURFACE IMPOUNDMENTS AND LANDFILL A GROUND WATER QUALITY
ASSESSMENT PROGRAM WAS IMPLEMENTED. THE RESULTS OF THIS PROGRAM
CONFIRMED THAT NO LEACHING OF LEAD HAD OCCURRED AT THE SITE.
DISSOLVED LEAD LEVELS, WERE EXTREMELY LOW IN ALL OF THE MONITORING
WELL SAMPLES. IN FACT, MOST OF THE WATER SAMPLES TAKEN FROM THE
ACTUAL POND WATER WERE ABLE TO MEET DRINKING WATER CRITERIA FOR
LEAD. THIS REPORT WAS SUBMITTED TO THE TEXAS WATER COMMISSION (TWC)
ON AUGUST 3,1988. THE TWC CONCLUDED FROM THIS REPORT THAT
"...COMPARISONS BETWEEN BACKGROUND AND DOWNGRADIENT WELLS
INDICATE NO STATISTICALLY SIGNIFICANT DIFFERENCES FOR THE METALS
CONCENTRATION." A COPY OF THE CONFIRMATION LETTER FROM SAMUEL B.
POLE, CHIEF; HAZARDOUS AND SOLID WASTE ENFORCEMENT SECTION,
HAZARDOUS AND SOLID WASTE DIVISION OF THE TWC IS ALSO ENCLOSED IN
APPENDIX H.
OTHER AGENCY CONCERNS
OTHER CONCERNS RAISED BY THE AGENCY INCLUDE MIXING, SEPARATION,
CONSISTENCY AND THE ABILITY TO CONTROL THE PROCESS. THESE CONCERNS
APPEAR TO COME FROM COMPARISONS MADE BETWEEN FOUNDRY SAND AND
LEAD PAINT REMOVAL WASTE. THE ISSUE RAISED ON PAGE 21 OF THE BATTELLE
REPORT COMPARES FOUNDRY SAND AND LEAD PAINT REMOVAL WASTE AS
BEING SIMILAR. CONCLUSIONS REACHED IN THE ASSESSMENT OF PAINT
REMOVAL WASTE WOULD NOT BE APPROPRIATE IN ASSESSING THE
EFFECTIVENESS OF FOUNDRY SAND STABILIZATION. THE PAINT REMOVAL
WASTE WOULD BE EXPECTED TO BE VERY DISSIMILAR IN SIZE AND HULK
DENSITY TO THE STEEL SHOT, AND WOULD LIKELY SEPARATE DURING THE
BLASTING OPERATION AS WELL AS DURING TRANSPORTATION AND DISPOSAL.
THE STABILIZATION OF FOUNDRY SAND IS PERFORMED UNDER CONTROLLED
CONDITIONS. THE SAND AND IRON ARE SIMILAR IN SIZE AND BULK DENSITY,
AND ARE THOROUGHLY BLENDED IN AN ENGINEERED SYSTEM. FOLLOWING ARE
TYPICAL FOUNDRY PRACTICES WHICH ASSURE A HETEROGENEOUS MIXTURE OF
FOUNDRY SAND AND IRON DUST.
TECHNIQUE FOR ADDITION AND TESTING OF IRON
THE MATERIAL DISPOSED OF IN THE ABOVE MENTIONED CITY OF
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NACOGDOCHES LANDFILL CAME FROM VARIOUS PROCESSES WITHIN NLBCO'S
OPERATIONS. THE MAJORITY OF THE MATERIAL WAS GENERATED IRON THE
CLOSURE OF THE LONG TERM ON-SITE SURFACE IMPOUNDMENTS AND
LANDFILL. THE MATERIAL WAS MIXED WITH IRON UTILIZING SEVERAL
ACCEPTED FOUNDRY PRACTICES FOR MATERIAL ADDITIONS AND MIXING
INCLUDING SCREW FEEDERS, BELT CONVEYORS, MULLOR MIXERS, AND
VOLUMETRIC ROTARY FEEDERS. RANDOM SAMPLES WERE GATHERED ON A
REGULAR BASIS TO TEST FOR THE PRESENCE OF AN ACCEPTABLE AMOUNT OF
IRON DUST. THE SAMPLES WERE WEIGHED AND DRIED. THE IRON WAS THEN
REMOVED FROM THE SAMPLES USING A MAGNET ALLOWING FOR A RELIABLE
FIELD DETERMINATION OF IRON DUST PERCENTAGE. NORMAL PROCEDURE WAS
TO TEST FOR IRON DUST PERCENTAGE ON AN HOURLY BASIS FOR CONTINUOUS
OPERATIONS AND ON EACH BATCH FOR BATCH PROCESSES.
QUALITY CONTROL
INITIAL QUALITY CONTROL PROCEDURES FOR THE ADDITION OF IRON DUST
WERE NOT FORMALIZED. IT WAS DETERMINED THAT 2.5% TO 5% IRON WAS
NEEDED TO ADEQUATELY TREAT MOST OF THE MATERIAL TO BELOW
REGULATORY LIMITS. BECAUSE OF THE POTENTIAL IMPLICATIONS OF
HAZARDOUS WASTE REGULATIONS, A GOAL OF 10% IRON WAS PLACED ON THE
ADDITION SYSTEM TO PROVIDE A SUFFICIENT LEVEL OF SAFETY AND ALLOW
FOR POTENTIAL UNCERTAINTIES IN THE MATERIAL MIX. WHILE UNTREATED
FOUNDRY SAND WILL TYPICALLY YIELD A TCLP TEST OF LESS THAN L 00 MG/L
FOR LEAD, CONCENTRATED WASTE STREAMS WITH AN INITIAL TCLP OF NEARLY
1000 MG/L WERE ABLE TO BE TREATED TO WITHIN REGULATORY LIMITS WITH
THE 10% IRON ADDITION. AS THE PROCESS PROGRESSED, QUALITY CONTROL
PROCEDURES WERE INITIATED TO FURTHER ASSURE PROPER ADDITIONS OF
IRON DUST. ATTACHED IN APPENDIX I ARE COPIES OF AVERAGE AND RANGE
CHARTS THAT WERE UTILIZED IN THE PROCESS FROM THREE SEPARATE WASTE
STREAM INPUTS. THE CHARTS ARE A SAMPLE OF THE CHARTS USED DURING THE
ACTIVE OPERATION OF THIS PROCESS.
TCLP TESTING
IN ADDITION TO IRON DUST PERCENTAGE TESTING, COMPOSITE SAMPLES WERE
REGULARLY SENT TO A LAB TO PERFORM THE APPROPRIATE EP-TOXICITY OR
TCLP TEST. THESE TESTS WERE PERFORMED APPROXIMATELY TWICE A MONTH.
ATTACHED IN APPENDIX J ARE COPIES OF THE COVER PAGE OF THESE TESTS FOR
1995 UNTIL SUSPENSION OF OPERATION OF THE LANDFILL FOR DISPOSAL. THE
TCLP FOR THESE SAMPLES RANGED FROM BELOW DETECTION TO 0.2 MG/L. THE
PERCENT IRON IN THE SAMPLES AS REPORTED BY NIBCO BASED ON
SEPARATION TESTS RANGED FROM 14.2% TO 22.6%. THESE RESULTS ARE WELL
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ABOVE THE REQUIRED 10%, BECAUSE IT WAS DETERMINED THAT THE COST OF
ADDITIONAL IRON WAS MINIMAL COMPARED WITH THE ADDED ASSURANCE OF
SUFFICIENT TREATMENT.
//ENDC1
RESPONSE
NIBCO does not agree with EPA's classification of iron dust treatment of foundry sands
as impermissible dilution, and made the following points:
1. Iron dust treatment provides long-term treatment of foundry sands and is not impermissible
dilution as EPA asserts; J
2. Data does not support EPA's position that lead is masked by the addition of iron;
t
3. EPA's conclusion about iron-lead bonds are not the same as the conclusion reached in the
Battelle report, which, acknowledges weak iron-lead bonds, however, concludes that long-
term stability is unknown;
4. NIBCO disagrees with EPA's assertion that over time when exposed to moisture and
oxidative conditions, interstitial water would likely acidify and thus, reverse stabilization and
increase leachability of the lead from the foundry sand;
5. Because waste foundry sand is commonly disposed of in a monofill, acetic acid is not likely
to be present and therefore, an alternative testing procedure should be used;
6. NIBCO also disagrees with the agency's concern with regards to controlling the process such
as blending and mixing. The commenter believed that foundry sand waste and wastes from
lead paint removal operations are dissimilar and that comparisons of these wastes should not
be used to characterize the foundry sand operations.
EPA disagrees with the commenter's position that iron dust treatment provides long-term
treatment. The Agency believes that it is unlikely that a chemical reaction occurs when iron dust is
added to foundry sands. Because the waste foundry sand would likely contain only lead, silica,
microscopic pieces of castings, and binders (clays, phenols, and tars) from the molds, EPA is not
convinced that the simple addition of iron would provide treatment for the lead or the organics (i.e.,
phenol and tar). While it may be argued that iron could form temporary and weak, ionic complexes
with silica and/or phenol, so that when analyzed by the TCLP test the lead appears to have been
stabilized; however, EPA believes that this "stabilization" is temporary, based upon the nature of the
complexing. In a report by EPA on Iron Chemistry in Lead Contaminated Materials (Feb. 22, 1994),
which specifically addressed this issue, EPA found that iron-lead bonds are weak, adsorptive, surface
bonds. EPA believes that these iron-lead bonds are not likely to be permanent. Studies conducted
by Dr. Drexler and Dr. Kendall also concluded that adding iron filings to spent foundry sand is not a
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permanent treatment for hazardous constituents, and indeed that "the lead is in mmo way altered or
immobilized." Kendall Report p. 2. EPA continues to believe that if this iron-rich mixture is
exposed to moisture and oxidative conditions over time, interstitial water would likely acidify, which
could potentially reverse any temporary stabilization, as well as increase the teachability of the lead
from the foundry sand.
Further, EPA continues to believe that the conditions exist that will allow such chemical
reactions to proceed to the extent whereby the stability of the treated lead-bearing waste deteriorates
which could result in lead leaching. The Battelle report's equilibrium diagrams indicate that
dissolved species predominate at pH levels below 6, and lead would likely remain as lead metal at
pH of 6 or greater. Further, the scientific literature has shown that under waterlogged conditions,
naturally occurring lead becomes reduced and mobile (Hazardous Waste Treatment, 1983. Brown,
Kirk, G. Evans and B. Frentrup, eds). In consideration of the above, EPA continues to believe that
the addition of iron dust or filings to D008 waste foundry sand does not appear to provide, long-term
treatment\stabilization.
The Agency has concluded that this form of stabilization is only a short-term solution, and
that it is inadequate to minimize the threats posed by land disposal of metal-containing hazardous
wastes. Because the short-term effect is a dilution phenomenon (Drexler Report, pp. 14, 16, 18),
EPA, therefore considers this technology "impermissible dilution" in accordance with 40 CFR 268.3.
Although the addition of iron dust or filings is considered treatment under 260.10, the Agency does
not believe it is adequate treatment; but merely the addition of material as a substitute for adequate
treatment and therefore constitutes impermissible dilution. See 40 CFR 268.3 (B), 54 FR at 48494
(November 1989), and 55 FR at 22532 (June 1, 1990). As discussed above, the Agency does not
believe any reaction occurs, and that the simple addition of iron does not provide adequate or long-
term, treatment.
The available data indicates that analytical masking (i.e., analytical interference) may not be
a problem, as evidenced by the available matrix spike recovery data. EPA has studied the chemistry
relative to this iron treatment process which indicates that when the mixture is dry there is no
reaction at all. e.g., See Kendall Report, p.2. However, once acetic acid is added (during TCLP
analysis) some oxidation reduction type chemistry may occur that may mask the lead from getting
into solution and hence, not be revealed in analytical analysis. However, the Agency points out that
the analytical method for lead is sufficient and it is during the extraction process that masking
occurs. EPA believes that iron treatment masks the TCLP results in that it passes the TCLP test
initially but may fail over the long-term. EPA also notes that RCRA requires that the TCLP analysis
for determination of TC hazardousness be determined at the point of waste generation (55 FR 11830
March 29, 1990). EPA notes that the TCLP testing by the foundry industry to demonstrate whether
the waste is in fact TC hazardous (and hence, require treatment) is typically performed after the
addition of the iron dust. The argument that the addition of iron dust is part of the process is not
valid and believes that the addition of iron dust or filings masks the presence of lead.
The commenter is correct in that the Battelle report did not state that the bonds are not
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permanent, but concluded that the long-term stability is unknown. However, the Agency remains
unconvinced about the long-term stability of this technology. The Agency realizes that this
technology has been in use only since the early 1980's and thus, there is little data available on long-
term effectiveness. The Agency compiled information on two different studies conducted on this
issue, one by Dr. John Drexler of the University of Colorado and the other by Dr. Douglas Kendall
of the National Enforcement Investigation Center (NEIC). These studies found that even after
treatment, high concentrations of lead remained available to the environment and also leached in the
units receiving the spent foundry wastes (measured by TCLP testing). Therefore, these studies
concluded that the addition of iron filings or iron dust to lead-contaminated spent foundry sands did
not constitute adequate treatment of the waste. See the March 5,1997 NODA (62 FR 10004) for a
full discussion of these studies. The conclusions reached by these studies were peer reviewed by an
expert panel. The peer reviewers agreed that adding iron filings to spent foundry sand is not
treatment of hazardous constituents in the ssense of actually impeding lead mobility. The peer
reviewers also found that the scientific data presented in the studies support the conclusions reached
and the studies are based on sound scientific research and fact. Therefore, the Agency reaffirms its
conclusion that the addition of iron filing constitutes impermissible dilution
The Agency is also codifying this determination by amending 40 CFR 268.3 to read as
follows:
40 CFR 268
§ 268.3 Dilution prohibited as a substitute for treatment
(d) It is a form of impermissible dilution, and therefore prohibited, to add iron filings or other
metallic forms of iron to lead-containing hazardous wastes in order to achieve any land disposal
restriction treatment standard for lead. Lead-containing wastes include D008 wastes (wastes
exhibiting a characteristic due to the presence of lead), all characteristic wastes containing lead as an
underlying hazardous constituent, listed wastes containing lead as a regulated constituent, and
hazardous media containing any of the aforementioned lead-containing wastes.
The Agency does not agree with the commenter's suggestion that an alternative analytical
testing procedure be used since the waste is disposed of in a monofill. EPA has established the
TCLP as the official required method for determining whether a waste is toxicity characteristic
hazardous. EPA's determination of the use of the TCLP was finalized on March 29, 1990 (55 FR
11798). This issue is not being reopened in this rulemaking. However, EPA reviewed the suitability
for testing the leachability of lead in foundry sand and continues to believe that TCLP testing is
appropriate for determining the characteristic of hazardousness for metal-bearing waste streams.
This issue is further discussed in the Technical Memorandum entitled "Iron Dust Treatment of Lead-
Bearing Foundry Sand," dated September 15, 1995, and can be found in the Administrative Record
for this rulemaking. With regard to the comment on the MELP, the Agency agrees that both TCLP
and MELP are acceptable analytical procedures. However, the Agency notes that the MELP is
designed to test the leachability of constituents on a longer term and therefore, a sample that passes
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the MELP is very unlikely to fail the TCLP. In addition, the Agency notes that the RCRA
regulations, as stated in 40 CFR 261.4(a), require TCLP, test method 1311 to determine wether the
leachate exhibits a hazardous characteristic.
With respect to the comment on the absence of current groundwater contamination, the
Agency notes that studies have shown leachate testing to be an ineffective measure of long-term
metal mobility and future monitoring may show contamination, should any landfill liner fail or
contamination reach the monitoring well.
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Issue: FOUN1-017 Respondent: TTS
Dcn:PH3P017 Extension: CBI:N
Commenter: THE TDJ GROUP, INC
Comment Number: 00001
//COMM1
//RESPTTS
//SUBJFOUN1-017
1) CRITICISM OF EPA WASTE CHARACTERIZATION PROCEDURES
AS YOU ARE AWARE, A PERFECT CHARACTERIZATION TEST FOR TOXICITY DOES
NOT EXIST. IN AN EFFORT TO PROVIDE A REASONABLE CONSERVATIVE TEST THAT
SIMULATES CONDITIONS IN AN ACIDIC LANDFILL, THE EPA IMPLEMENTED THE
CURRENT TCLP TEST NOW USED TO CHARACTERIZE D008 WASTES. ALTHOUGH THE
TCLP TEST REPLACED A PROCEDURE WHICH SIMULATED APPROXIMATELY 100
YEAR IN AN ACIDIC LANDFILL, THE SHORT-TERM NATURE OF THE TCLP TEST DOES
NOT TAKE INTO ACCOUNT THE POSSIBILITY FOR SHORT AND MEDIUM TERM
CHEMICAL CHANGE IN THE WASTE WHICH COULD LEAD TO AN UNACCEPTABLE
RELEASE OF LEAD OR OTHER INORGANICS. IN ADDITION, THE ACIDIC NATURE OF
THE TEST DOES NOT ALLOW CONSIDERATION OF THE PERFORMANCE OF THE
WASTE IN A MORE ALKALINE ENVIRONMENT. THIS IS OF SOME CONCERN, SINCE
THE D--9 BOAT RECOMMENDED BY TEN AGENCY INVOLVES THE USE OF BASIC
SILICATE STABILIZATION TECHNOLOGIES, SUCH AS PORTLAND CEMENT, AND LEAD
IS AMPHOTERIC. EXCESSIVE ELEVATION OF PH WITH NO OTHER CHANGES MAY
CREATED CONDITIONS OF ELEVATED LEAD MOBILITY IN BASIC ENVIRONMENTS.
IT IS THE EXPERIENCE OF THE AUTHORS OF THIS LETTER THAT TESTING
PROCEDURES CAN BE USED TO MAKE A SERIES OF POINTS FOR AND AGAINST
CURRENT AGENCY TESTING METHODS, BUT MORE THOUGHTFUL AND CAREFUL
APPLICATION OF VARIOUS AGENCY TEST METHODS SEEMS TO SUPPORT THE
CONCENTRATION THAT THE TCLP OFFERS A REASONABLY CONSERVATIVE (BUT
INCOMPLETE) VIEW OF WASTE STABILITY. FOR EXAMPLE, IN A RECENT FHWA
REPORT (REVIEWED BY EPA STAFF), SAMPLES OF SILICATE AND IRON TREATED
D008 WASTES WERE SUBJECTED TO SINGLE AND MULTIPLE TCLP TESTING AND MEP
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TESTING.
SILICATE ADDITIONS TO ABRASIVE USED ON LEAD BASED PAINT CREATES A WASTE
WHICH EXHIBITS LONG TERM STABILITY. THIS IS EVIDENT BY THE WASTE'S
ABILITY TO WITHSTAND CYCLED ACIDIC ENVIRONMENTS IN FIVE SEQUENTIAL
TCLP TESTS AND THE MEP TEST. IN BOTH CASES THE WASTE SHOWED NO TRENDS
TOWARDS INCREASING LEAD LEACHABILITY.
IN THE SAME SET OF TESTS, IRON TREATED ABRASIVE WAS UNABLE TO SURVIVE
THE MEP TEST, APPARENTLY DUE TO THE PROGRESSIVE CORROSION OF THE IRON
FILLING USED IN THE WASTE DURING THE TEST. THIS SAME WASTE PASSED THE
TCLP TEST, AND WAS CAPABLE OF PASSING MULTIPLE TCLP TESTS AS LONG AS THE
TESTS WERE PERFORMED OVER A SHORT SPAN OF TIME.
THERE APPEARS TO BE SUFFICIENT INFORMATION AVAILABLE TO THE AGENCY IN
PUBLISHED FORM THAT SUGGESTS THAT IRON TREATED WASTES WILL NOT
REMAIN STABLE IN ACIDIC ENVIRONMENTS. IT ALSO SEEMS CLEAR THAT WE DO
NOT HAVE CORRESPONDING TESTING DATA TO ADDRESS THE SAME ISSUE IN A PH
NEUTRAL OR ALKALINE DISPOSAL ENVIRONMENT.
FROM THE STANDPOINT OF TESTING PROCEDURES, THE AUTHORS OF THIS LETTER
SUGGEST THAT THE TCLP TEST IS NECESSARY BUT NOT SUFFICIENT FOR TESTING
IRON TREATED D008 WASTES. THIS WASTE MATERIAL IS SOMEWHAT EXCEPTIONAL
IN THAT WE CAN CLEARLY SEE THE PROCESS THAT WILL ALLOW THE MATERIAL TO
FAIL (RUSTING OF THE IRON), AND WE NOTE THE INABILITY OF THE TEST TO
SIMULATE THE SAME. RATHER THAN DAMNING THE EXISTING TESTING
PROCEDURE, WE WOULD ADVISE THE AGENCY TO CONSIDER THESE WASTES AS A
SEPARATE MATERIAL UNDER THE REGULATIONS, AND TO USE THAT STATUS TO
MODIFY THE TESTING AND TREATMENT REQUIRED FOR LAND DISPOSAL.
2) ARGUMENTS SUGGESTING THAT THE PROPOSED RULING DOES NOT OR SHOULD
NOT APPLY TO PARTICULAR CONDITIONS OF DISPOSAL
PRELIMINARY DATA FORM THE FOUNDRY INDUSTRY (OUTLINED IN THE AMERICAN
FOUNDRYMANS SOCIETY RESPONSE) SUGGESTS THAT MONOFILLING OF THESE
WASTES SHOWS NO EVIDENCE OF LEAD MOBILITY IN SOIL TESTS AND IN
GROUND WATER MONITORING. THESE DATA NEED TO BE UNDERSTOOD WITHIN
THE CONTEXT OF THE LARGER PROBLEM THE AGENCY FACES. LIMITED DATA ON
GROUND WATER MONITORING FROM THE FOUNDRY INDUSTRY (BOTH HARD AND
ANECDOTAL DATA) APPEAR TO SHOW LITTLE EVIDENCE THAT THE MOST COMMON
LEADED ALLOYS IN USE BY THE INDUSTRY HAVE MIGRATED WHEN DISPOSED TO
MONOFILLS. THESE DATA COULD INCLUDE EVIDENCE OF A LACK OF MOBILITY
OVER PERIODS OF TIME THAT EXTEND BEFORE RCRA AND THE ADOPTION OF IRON
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TREATMENT PRACTICES (PRE-1978). NO CONCLUSIVE DATA ARE AVAILABLE TO
REFLECT THE PERFORMANCE OF IRON TREATMENT OVER DECADES, SINCE THE
PRACTICE WAS FIRST INTRODUCED IN THE FOUNDRY INDUSTRY IN 1985. NO
CONCLUSIVE DATA ARE AVAILABLE TO CLEARLY MODEL THE MOBILITY OR LACK
OF MOBILITY OF COMMON FOUNDRY LEAD ALLOYS IN LESS ACIDIC LAND
DISPOSAL ENVIRONMENTS. IT WOULD SEEM CLEAR, HOWEVER, THAT DISPOSAL OF
IRON-TREATED BRASS CONTAMINATED FOUNDRY WASTES IN ALKALINE
MONOFILLS SHOULD BE ANALYZED DIFFERENTLY THAN DISPOSAL OF SPENT LEAD-
CONTAMINATED ABRASIVE IN ACIDIC LANDFILLS.
3) ARGUMENTS SURROUNDING POINT OF GENERATION ISSUES
POINT OF GENERATION ISSUES HAVE ALREADY SURFACED AS A MATERIAL
PORTION OF THIS RULEMAKING.
IT SHOULD BE NOTED THAT PROCESS CHANGE FOR THE PURPOSES OF WASTE
REDUCTION OR MOTIVATION IS ALREADY AN AREA OF SUBSTANTIVE ACTIVITY IN
BOTH THE FOUNDRY AND STEEL MAINTENANCE INDUSTRIES. IN THE SUBJECT
AREAS OF OPERATION (RECYCLING OF MOLDING SANDS, APPLICATION OF STEEL
GRIT, APPLICATION OF SILICA BASED ABRASIVE WITH IRON ADDITIONS), IRON
DUST AND/OR STEEL GRIT CAN SURVIVE THE ENTIRE USE ENVIRONMENT. IN
SHORT, THIS MEANS THAT NO MATTER WHERE THE "POINT OF GENERATION" IS
DEFINED BY THE AGENCY, IT WILL BE POSSIBLE TO ADD IRON DUST UPSTREAM OF
THAT POINT, THEREBY AVOIDING SUBTITLE C REGULATION OF THE WASTE. IF THE
AGENCY FEELS THAT THIS PROCESS OF WASTE CHANGE OR TREATMENT IS NOT AN
ACCEPTABLE PRACTICE, USE OF POINT OF GENERATION ISSUES MAY NOT BE
EFFECTIVE IN RESTRICTING THESE ACTIVITIES.
4) SUGGESTIONS THAT THE PROPOSED RULE DOES NOT PROMOTE WASTE
MINIMIZATION
IF THE AGENCY ACTS TO DISCOURAGE THE USE OF IRON MATERIALS AS
TREATMENT AGENTS, THIS MAY HAVE AN IMPACT ON THE SALE AND USE OF
RECYCLABLE STEEL ABRASIVE IN STEEL MAINTENANCE AND DELEADING
APPLICATIONS. ONE OF THE ARGUMENTS OFFERED IN THIS AREA IS THE
SUGGESTION THAT RECYCLABLE STEEL GRIT REPRESENTS AN OPPORTUNITY TO
MINIMIZE WASTES GENERATED THROUGH THE USE OF "NON-RECYCLABLE"
ABRASIVE. IN TRUTH, ALL OF THE SLAG "NON-RECYCLABLE" ABRASIVE IS IN FACT,
A RECYCLED WASTE MATERIAL IN ITS OWN RIGHT. THESE MATERIALS INCLUDE
RECYCLED COAL SLAGS, COPPER SLAGS, STEEL SLAGS, AND NICKEL SLAGS. NO
MATTER WHICH WAY THE AGENCY FINALLY RULES ON THIS MATTER, IT WILL BE
PROVIDING SUPPORT FOR ONE OR MORE OF A SERIES OF RECYCLING EFFORTS.
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WE WOULD MAKE A SERIES OF OBSERVATIONS AND CONCLUSIONS BASED ON THE
ABOVE INFORMATION:
THE TCLP TEST IS A CONSERVATIVE, BUT IMPERFECT MEASURE OF HEAVY
METALS MOBILITY POTENTIAL IN LANDFILLS;
THE TCLP TEST MAY NOT ACCURATELY REFLECT THE POTENTIAL MOBILITY OF
HEAVYMETALS IN MONOFILLS AND NON-LANDFILL ENVIRONMENTS;
IRON TREATED WASTES FROM BOTH THE FOUNDRY INDUSTRY AND THE LEAD
PAINT ABATEMENT OF STEEL STRUCTURES (SPENT ABRASIVE WASTE) ARE BEING
DISPOSED IN SANITARY LANDFILLS WITH ACID LEACHATES PRESENT;
IN ACIDIC ENVIRONMENTS WITH SUFFICIENT MOISTURE AND OXYGEN, IRON
WILL RUST AND THE TREATMENT REACTIONS WtLL BE REVERSED;
IF THE LEAD COMPOUNDS ARE MOBILE WITHOUT TREATMENT, THEY WILL
LEACH AFTER THE IRON IS OXIDIZED;
GOVERNMENT EFFORTS TO STOP THE PROCESS OF IRON DUST TREATMENT
THROUGH AGGRESSIVE DEFINITION OF POINTS OF WASTE GENERATION WILL
PROBABLY NOT BE EFFECTIVE;
STOPPING THIS TREATMENT PROCESS FOR LEADED WASTES WILL PROBABLY
HAVE NOT IMPACT ON WASTE MINIMIZATION ACTIVITIES.
//COMM2
//RESPRIA
//SUBJREGR1
WHAT CAN THE AGENCY DO TO RESTRICT THESE IRON TREATMENT ACTIVITIES? IF
THE OBSERVATION THAT POINT OF GENERATION IS NOT AN EFFECTIVE MEANS OF
REGULATING THIS PRACTICE, THEN WE WOULD SUGGEST THAT THE GOVERNMENT
CONSIDER LISTING IRON AND LEAD RICH WASTE STREAMS (FROM BRASS FOUNDRY
CASTING SANDS, BRASS FOUNDRY STEEL GRIT CLEANING SYSTEMS, IRON TREATED
SPENT ABRASIVE AND THE RESIDUE FROM MOBILE STEEL GRIT SYSTEMS USED IN
LEAD PAINT ABATEMENT) AS HAZARDOUS, WITH A CLEARLY DEFINED PATH FOR
DELISTING. OUR DATA SUGGEST THAT THERE ARE THREE POTENTIAL TYPES OF
WASTE GENERATORS THAT WOULD BE IMPACTED BY SUCH A DECISION: LARGE
FOUNDRIES WITH THEIR OWN MONOFILLS, SMALLER FOUNDRIES USING OFFSITE
COMMERCIAL DISPOSAL FACILITIES, AND SAND BLASTING CONTRACTORS THAT
MOVE FROM JOB SITE TO JOB SITE. LARGER FOUNDRIES WITH MONOFILLS ARE
DISPOSING OF THE MATERIAL IN A POTENTIALLY LESS ACIDIC ENVIRONMENT AND
35
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HAVE THE RESOURCES TO GO THROUGH A DELISTING PROCESS. SMALLER
FOUNDRIES DO NOT HAVE THE ABILITY TO DELIST, BUT THE AGENCY COULD
PRESCRIBE A METHOD OF TREATMENT (SILICATE STABILIZATION) NECESSARY TO
DISPOSE OF THE MATERIAL. ABRASIVE APPLICATORS WORK MULTIPLE SITES IN A
GIVEN YEAR, SO DESLISTING WOULD NOT BE AN OPTION. SINCE THIS IS THE AREA
OF GREATEST USE OF IRON DUST TREATED WASTES, THIS WOULD DISCOURAGE THE
PRACTICE.
BASED ON THE SPEED OF NEW TECHNOLOGY DEVELOPMENT IN THIS AREA, AS
WELL AS THE AVAILABILITY OF EXISTING TECHNOLOGIES, THIS ACTION BY THE
GOVERNMENT WOULD PROBABLY HAVE LITTLE ECONOMIC IMPACT ON THE
REGULATED COMMUNITY. CURRENTLY METHODS NOT UTILIZING IRON
TREATMENT IN THE ABRASIVE INDUSTRY NOW COST ABOUT THE SAME PER
SQUARE FOOT OF PAINT REMOVAL AS METHODS UTILIZING THE PRACTICE OF IRON
ADDITION. FOR EXAMPLE, THE DIFFERENCE IN COST OF PAINT REMOVAL BETWEEN
IRON AND NON-IRON ADDITION IS ABOUT $0.15 TO $0.25 PER SQUARE FOOT (IRON
ADDITION IS SLIGHTLY CHEAPER). ON A PROJECT WHERE THE AVERAGE COST OF
PAINT REMOVAL TYPICALLY RUNS FROM $6.00 TO $15.00 PER SQUARE FOOT, A
SMALL CHANGE IN THE COST OF DISPOSAL WILL NOT MATERIALLY AFFECT THE
USE OF TECHNOLOGY.
//ENDC1
RESPONSE
The TDJ Group submitted comments making the following observations and conclusions:
1. The TCLP test is an imperfect measure of heavy metals mobility potential at landfills,
monofills, and non-landfill environments;
2. Iron-treated foundry sands disposed of in alkaline monofills should be analyzed differently
than spent lead-contaminated abrasives disposed of in acidic landfills;
3. Defining the point of generation will not be effective in stopping the use of the process to
avoid Subtitle C jurisdiction; and
4. The proposed rule may not have an impact on waste minimization.
The Agency has determined that the TCLP test is the approved analytical procedure for
determining whether a waste exhibits the toxicity characteristic for metal-bearing wastes. EPA's
determination of the use of the TCLP was finalized on March 29, 1990 (55 FR 11798). This issue is
not being reopened in this ralemaking. However, EPA reviewed the suitability for testing the
teachability of lead in foundry sand and continues to believe that TCLP testing is appropriate for
determining the characteristic of hazardousness for metal-bearing waste streams. This issue is
further discussed in the Technical Memorandum entitled "Iron Dust Treatment of Lead-Bearing
Foundry Sand," dated September 15, 1995, and can be found in the Administrative Record for this
36
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rulemaking.
In any case, the Agency is not reopening the issue of the proper test for determining toxicity.
Rather, the issue is whether a particular method of treatment minimizes threats posed by land
disposal of a hazardous waste. The ultimate conclusion in this proceeding is that addition of iron
filings is an inadequate method for treating D008 wastes since lead is not immobilized. Rather, the
analytic compliance method is blinded. This is a form of dilution. See also Drexler Report at pp. 14,
16, 18 (addition of iron filings results in a dilution effect, not actual immobilization).
As stated above the Agency has determined that the TCLP test is the approved analytical
procedure for determining whether a waste exhibits the toxicity characteristic for metal-bearing
wastes. Again, the issue in this proceeding is entirely different: evaluation of the adequacy of a type
of treatment process. The Agency is not reopening the question of a method for identifying which
wastes are hazardous, and comment responses are included only in the event a response to these
unsolicited points is considered to be necessary. Regarding the point of generation issues, EPA
notes that RCRA requires that the TCLP analysis for determination of TC hazardousness be
performed at the point of waste generation (55 FR 11830 March 29, 1990).
EPA acknowledges the comment that curtailing treatment of lead-containing foundry sand by
addition of iron dust process may not impact waste minimization activities.
37
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Issue: FOUN1-040 Respondent: TTS
Den: PH3P040 Extension: CBI: N
Commenter: AMERICAN FOUNDRYMEN'S SOCIETY, INC
Comment Number: 00001
//COMM1
//RESPTTS
//SUBJFOUN1-040
IRON ADDITION TO FOUNDRY WASTE IS NOT DILUTION
EPA'S REFERENCE TO IRON FILINGS TREATMENT USED BY THE FOUNDRY INDUSTRY
AS BEING IMPERMISSIBLE DILUTION IS NOT VALID. NO SUPPORTING
DOCUMENTATION CITED IN THE FEDERAL REGISTER NOTICE JUSTIFIES THE EPA'S
POSITION. THE REPORT, CITED BY EPA AS SUPPORTING IT'S POSITION IS BATTELLE'S
"IRON CHEMISTRY IN LEAD CONTAMINATED MATERIALS" (DATED FEBRUARY 22,
1994, PREPARED FOR EPA S RISK REDUCTION ENGINEERING LABORATORY,
CINCINNATI, OHIO AND REFERRED TO IN THIS LETTER AS THE BATTELLE REPORT).
THIS REPORT SPECIFICALLY INDICATES DOSAGE RATES USED BY FOUNDRIES OF 1
TO 10% AS EFFECTIVELY LOWERING THE LEAD LEACHABILITY FROM THE ORIGINAL
LEVEL OF WELL OVER 100 PPM TO LESS THAN 5 PPM IN THE WASTE TESTED. IF THE
TWENTY-FOLD REDUCTION IN LEAD CONCENTRATIONS WAS SOLELY DUE TO
DILUTION, AN 800% TO 5000% ADDITION WOULD BE REQUIRED, 10% WOULD NOT BE
SUFFICIENT. IT IS A CHEMICAL REACTION, NOT SIMPLE DILUTION, THAT IS
STABILIZING THE LEAD IN THE FOUNDRY WASTES. THE SCIENTIFIC AND
TECHNICAL DISCUSSION OF THE CHEMICAL REACTIONS INVOLVED ARE
CONTAINED IN COMMENTS SUBMITTED BY RMT, INC. REGARDING THE MARCH 2ND
FEDERAL REGISTER.
IRON IS NOT MASKING TCLP RESULTS
IT IS OUR UNDERSTANDING THAT SINCE THE PUBLICATION OF THE MARCH 2ND
FEDERAL REGISTER, EPA HAS ESTABLISHED THAT THE CONCLUSIONS IN THE
DATANET REPORT ARE INCORRECTJ.E IRON DOES NOT INTERFERE WITH THE TCLP
ANALYSIS FOR LEAD (SEE PHONE MEMOS ON DISCUSSIONS BETWEEN EPA STAFF
38
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AND RMT IN APPENDIX E). BASED ON THIS DETERMINATION, THE ARGUMENT THAT
IRON IS MASKING THE TCLP TEST IS UNFOUNDED AND SHOULD 'BE REMOVED FROM
DISCUSSION.
BATTELLE REPORT
THE JANUARY, 1994 BATTELLE REPORT RECOGNIZES THAT THERE ARE DATA GAPS
AND ISSUES AND PROPOSES SIX EXPERIMENTS TO ANSWER QUESTIONS ON TOPICS
INCLUDING: IRON SEGREGATION IN WASTES, ECONOMIC FEASIBILITY, EMPLOYEE
SAFETY AND HEALTH, OPTIMAL PROPERTIES OF THE IRON, AND STABILITY OVER
TIME. ANOTHER ISSUE IS RAISED BY THE COMMENT ON PAGE 21 OF THE BATTELLE
REPORT. "WASTE GENERATED BY REMOVAL OF LEAD PAINT FROM STRUCTURES
HAS SOME SIMILARITIES TO SPENT CASTING SAND. BOTH THE CASTING SAND AND
ABRASIVE BLASTING MEDIA WASTE ARE A SILICATE MATRIX CONTAINING
LEACHABLE LEAD CONTAMINATION. HOWEVER,THE LEAD SPECIES PRESENT AND
THE TYPE AND CONDITION OF THE SAND ARE DIFFERENT."
THE ABOVE PROCESSES ARE QUITE DIFFERENT IN CHARACTER. FOUNDRY SAND
STABILIZATION IS PERFORMED UNDER CONTROLLED CONDITIONS WITH DISPOSAL
PLACEMENT CAREFULLY CONTROLLED. THE ADDED SAND GRAINS AND IRON
PARTICLES ARE APPROXIMATELY THE SAME SIZE AND DENSITY, ARE THOROUGHLY
BLENDED IN AN ENGINEERED SYSTEM, AND WILL NOT SEPARATE AFTER
STABILIZATION. THE PAINT, ON THE OTHER HAND, IS NOT TREATED BUT TAKES
ADVANTAGE OF IRON PRESENT DUE TO THE USE OF IRON OR STEEL SHOT TO
REMOVE THE PAINT. THIS BLASTING PROCESS IS MUCH LESS CONTROLLED THAN
THE FOUNDRY SAND STABILIZATION PROCESS. PAINT FLAKES AND IRON
PARTICLES ARE NOT OF THE SAME SIZE AND DENSITY SO MIXING IS LESS
EFFECTIVE. THE DIFFERENCES IN LEAD SPECIES IN PAINT AND FOUNDRY PRODUCTS
EXPLAIN WHY IRON STABILIZES LEAD BEARING FOUNDRY WASTES, BUT DOES NOT
IMMOBILIZE LEAD IN PAINT FLAKES.
IN LIGHT OF THE RECOMMENDATIONS MADE IN THE BATTELLE REPORT AND WITH
NO DOCUMENTATION REFERENCED IN THE FEDERAL REGISTER NOTICE THAT
SUBSTANTIATES ENVIRONMENTAL HARM DUE TO FOUNDRIES USING THIS
STABILIZATION TECHNIQUE, WE QUESTION THE EPA'S DECISION TO MAKE A
DETERMINATION THAT IRON ADDITIONS TO FOUNDRY WASTE IS IMPERMISSIBLE
DILUTION.
IF EPA FEELS THAT 10% IRON ADDITIONS TO FOUNDRY WASTES IS DILUTION, THEN
THEY SHOULD ALSO CONSIDER REEVALUATING OTHER COMMONLY USED
TREATMENT TECHNOLOGIES, SUCH AS LIME ADDITIONS, TO DETERMINE IF THE
STABILIZATION OBTAINED MIGHT ALSO BE MASKING THE TCLP TEST OR BE
DILUTION.
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EPA HAS MORE FOUNDRY INFORMATION THAN IS REFERENCED IN MARCH 2, 1995
FEDERAL REGISTER
DURING THE LAST THREE YEARS, EPA HAS REQUESTED AND RECEIVED THOUSANDS
OF PAGES OF INFORMATION FROM BRASS FOUNDRIES IN BOTH REGIONS V AND VI
REGARDING THEIR USE OF IRON TO STABILIZE LEAD IN FOUNDRY WASTES. THIS
INFORMATION INCLUDES LABORATORY ANALYSIS, TREATMENT METHODS AND
PROCESSES, QUALITY ASSURANCE PROGRAMS, DAILY RECORDS OF QUANTITIES OF
MATERIAL STABILIZED, LANDFILL DATA, GROUND WATER MONITORING DATA AND
OPERATIONAL HISTORY. NONE OF THIS INFORMATION IS CITED BY EPA IN THE
MARCH 2, 1995 FEDERAL REGISTER.
WE CAN ONLY ASSUME THAT EPA IN WASHINGTON IS EITHER NOT AWARE OF THIS
DATA, OR HAS CHOSEN TO IGNORE IT IN THE PROPOSED RULE MAKING. MANY OF
THE CRITICAL QUESTIONS RAISED BY BATTELLE'lN THEIR JANUARY, 1994 REPORT
TO EPA MIGHT HAVE BEEN ANSWERED HAD EPA CHOSEN TO INCLUDE THIS
INFORMATION AS PART OF A COMPLETE AND THOROUGH INVESTIGATION ON THE
USE OF IRON TO IMMOBILIZE LEAD IN FOUNDRY WASTES.
CASE STUDIES FROM FROUNDRIES PRACTICING IRON TREATMENT OPERATIONS
IN AN ATTEMPT TO ALLEVIATE THIS SITUATION, AFS IS SUBMITTING ACTUAL DATA
FROM FOUR FOUNDRIES AS CASE STUDIES. THIS DATA IS INCLUDED IN APPENDICES
A-D AND WILL SHOW THE FOLLOWING:
1. IRON ADDED TO LEAD BEARING WASTE FOUNDRY SAND EFFECTIVELY
IMMOBILIZES THE LEAD AND YIELDS A PRODUCT THAT CONSISTENTLY PASSES
TCLP.
2. THE PROCESS OF MIXING WASTE FOUNDRY SAND WITH IRON IN THE
FOUNDRY ENVIRONMENT IS A CONTROLLED PROCESS COMPARABLE TO THE
MULLING AND MIXING OF THE SAND IN THE PRODUCTION PROCESS.
3. RECENT TCLP TESTS, RUN ON FOUNDRY SAND THAT WAS TREATED WITH
IRON AND LANDFILLED 8-10 YEARS AGO, YIELD LEAD RESULTS BELOW THE 5 PPM
LEVEL.
4. GROUNDWATER DATA FROM MONITORING WELLS AT ON-SITE PERMITTED
DISPOSAL FACILITIES CONFIRM THAT LEAD LEVELS ARE WELL BELOW FEDERAL
DRINKING WATER STANDARDS.
5. MONITORING WELL DATA ALSO SUGGESTS GROUNDWATER IS NOT IMPACTED
BY PAST SURFACE IMPOUNDMENTS THAT CONTAINED LEAD BEARING WASTE
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FOUNDRY SAND WHICH HAD NOT BEEN TREATED WITH IRON.
6. ANALYSIS FOR TOTAL IRON FROM LANDFILL SAMPLES PROVIDE RESULTS
THAT CLEARLY SHOW THE IRON HAS NOT OXIDIZED AFTER SEVERAL YEARS.
THE MATERIAL CONTAINED IN APPENDICES A-D IS BEING SUBMITTED TO CLARIFY
ISSUES AND PROVIDE THE DATA SUPPORTING AFS1 POSITION FOR EPA REVIEW.
IRON TREATMENT HAS LONG TERM STABILITY
EPA HAS EMPHASIZED THAT IRON TREATMENT IS NOT EFFECTIVE DUE TO THE
POTENTIAL FOR OXIDATION OF IRON IN A LANDFILL. THIS WOULD ALLOW THE
LEAD TO LEACH OUT OVER TIME. ON PAGE 11731 EPA'S POSITION IS THAT THE
STABILIZATION IS TEMPORARY. AFS HAS NOT BEEN ABLE TO FIND
DOCUMENTATION TO SUPPORT THE AGENCY'S P6siTION. AFS DOES NOT KNOW OF
ANY TECHNICAL EVIDENCE SUPPORTING THE EPA'S POSITION AND BELIEVES THAT
LONG-TERM STABILITY HAS BEEN DEMONSTRATED. THE FOUNDRY INDUSTRY HAS
A DEMONSTRATION OF LONG-TERM EFFECTIVENESS IN THE LANDFILL BASED ON
ACTUAL BORINGS AND ANALYSES CONDUCTED UNDER EPA APPROVAL. APPENDIX
C CONTAINS A REPORT ENTITLED CHARACTERIZATION OF FOUNDRY WASTE
DISPOSED AT THE NACOGDOCHES MUNICIPAL LANDFILL." THE RESULTS
DOCUMENT THAT THE IRON TREATED FOUNDRY WASTES PLACED IN THE LANDFILL
ARE STILL PROVIDING EFFECTIVE LEAD STABILIZATION AND THE IRON HAS NOT
OXIDIZED. THE REPORT CLEARLY INDICATES THAT EFFECTIVE TREATMENT IS IN
PLACE AND THAT THE TCLP RESULTS CORRELATE DIRECTLY WITH THE LEVEL OF
TOTAL IRON.
TO DATE AFS CONTINUES TO REVIEW DATA RELATIVE TO IRON FILINGS
TREATMENT AND HAS ALSO REVIEWED RMT'S RESULTS FROM MULTIPLE
EXTRACTION PROCEDURE (MEP). MEP IS THE ONLY MODEL AVAILABLE AND
INDICATES EFFECTIVE TREATMENT FOR 1000 YEARS. FIELD STUDIES SUPPORT THE
MODEL. WE SIMPLY DO NOT SEE THE JUSTIFICATION FOR THIS RULING. ON WHAT
TECHNICAL BASIS IS EPA PROMOTING THIS RULEMAKING AND WHERE ARE THE
FACTS?
DISCUSSIONS NEEDED ON THERMAL SAND RECLAMATION
IN THE MARCH 2, 1995 FEDERAL REGISTER, EPA REFERENCES THE FOUNDRY
INDUSTRY'S PRACTICE OF RECYCLING FOUNDRY SAND BY THERMALLY OXIDIZING
IMPURITIES (PAGE 11731). THIS TECHNOLOGY HAS BEEN FOUND TO BE AN
EFFECTIVE POLLUTION PREVENTION MEASURE THAT REDUCES WASTES BY 80%
WHILE RETURNING RAW MATERIALS TO THE CASTING PROCESS. LETTERS FROM
THE STATES OF CALIFORNIA AND NORTH CAROLINA SPECIFICALLY COMMENDING
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FOUNDRIES IN THEIR STATES FOR IMPLEMENTATION OF THIS TECHNOLOGY AND
ARE FOUND IN APPENDIX E. OTHER FOUNDRIES ARE PRESENTLY'CONSIDERING
INSTALLATION OF THIS TECHNOLOGY AS AN INTEGRAL PART OF THEIR SAND
SYSTEMS TO REDUCE SOLID WASTES. THERMAL TREATMENT OF FOUNDRY SAND IS
A CALCINING OPERATION AND NOT INCINERATION. AS EXPRESSED IN THE GMD
COMMENTS, SUBMITTED IN RESPONSE TO THIS PROPOSAL, "THE CALCINING
PROCESS DOES NOT CHANGE THE CHEMICAL, BIOLOGICAL, OR PHYSICAL
CHARACTER OR COMPOSITION OF THE SAND, I.E. SILICA, SILICON DIOXIDE (SIO2)."
GMD'S COMMENTS CLARIFY THE DIFFERENCES BETWEEN THERMAL RECLAMATION
OF FOUNDRY SANDS AND HAZARDOUS WASTE INCINERATION AS PRACTICED BY
OTHER INDUSTRIES.
//ENDC1
RESPONSE
AFS submitted comments objecting to EPA's position against addition of iron dust to foundry
sand. The main points of contention are:
Iron addition to foundry sand is not dilution as EPA categorizes the process, and, the Battelle
report recognizes that there are data gaps on issues, and therefore, AFS questions how EPA was able
to make the determination that iron dust treatment of foundry sand is impermissible dilution; The
commenter pointed out that many data were not cited in the March 2, 1995 Federal Register, and
submitted some data of their own;
1. Iron is not masking lead analysis in TCLP results;
2. Lead species are different in the foundry product from that of spent abrasive blasting media,
and this difference explains why iron dust treatment works for stabilizing foundry sands;
3. Iron dust treatment of foundry sands provides long-term stability; and
4. Thermal reclamation of foundry sand is an effective pollution prevention measure.
EPA continues to believe that iron dust should be classified as impermissible dilution, as well
as a method of treatment that in fact fails to minimize the threats posed by land disposal of D008
wastes. It is unlikely that a chemical reaction occurs when iron dust is added to foundry sands. See,
e.g. Kendall Report p. 2. Because the waste foundry sand would likely contain only lead, silica,
microscopic pieces of castings, and binders (clays, phenols, and tars) from the molds, EPA is not
convinced that the simple addition of iron would provide treatment of the lead or the organics (i.e.,
phenol and tar). Although it is arguable that iron could form temporary and weak, ionic complexes
with silica and/or phenol, so that when analyzed by the TCLP test the lead appears to have been
stabilized, EPA believes that this "stabilization" is temporary, based upon the nature of the
complexing. In fact, a report by EPA on Iron Chemistry in Lead Contaminated Materials (Feb. 22,
1994), which specifically addressed this issue, found that iron-lead bonds are weak, adsorptive
42
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surface bonds. Furthermore, as this iron-rich mixture is exposed to moisture and oxidative
conditions over time, interstitial water would likely acidify, which could potentially reverse any
temporary stabilization, as well as increase the leachability of the lead from the foundry sand.
EPA, therefore believes that the iron-lead bonds are not likely to be permanent.
With respect to the masking issue, the available data indicate that analytical masking (i.e.,
analytical interference) may not be a problem, as evidenced by the available matrix spike recovery
data. EPA has studied the chemistry relative to iron dust treatment which indicates that when the
mixture is dry there is no reaction at all. However, once acetic acid is added (during TCLP analysis)
some oxidation reduction type chemistry may occur that may mask the lead from getting into
solution and hence, not be revealed in analytical analysis. EPA believes that iron treatment masks
the TCLP results in that it passes the TCLP test initially but may fail in a longer term. EPA also
notes that RCRA requires that the TCLP analysis for determination of TC hazardousness be
determined at the point of waste generation.
The Agency acknowledges that there are data gaps with respect to iron dust treatment of
foundry sands. To EPA's knowledge, this technology has been in use only since the early 1980's
and, thus, there is little data available on long-term effectiveness. The Agency reviewed available
data for promulgating this rule including data submitted by commenters that included data from
Regions V and VI. The Agency also compiled information on two different studies conducted on
this issue, one by Dr. John Drexler of the University of Colorado and the other by Dr. Douglas
Kendall of the National Enforcement Investigation Center (NEIC). These studies found that even
after treatment, high concentrations of lead remained available to the environment and also leached
in fact from spent foundry wastes in actual disposal units. Therefore, these studies concluded that
the addition of iron filings or iron dust to lead-contaminated spent foundry sands did not constitute
adequate treatment of the waste; there is palpable failure to minimize threats posed by land disposal
due to inability to immobilize lead. See the March 5, 1997 NODA (62 FR 10004) for a full
discussion of these studies.
The Agency strongly believes that this form of stabilization is only a short-term measure at
best, and that it is inadequate to minimize the threats posed by land disposal of metal-containing
hazardous wastes. EPA, therefore considers this technology "impermissible dilution" in accordance
with 40 CFR 268.3, given the dilutive nature of the phenomenon. Drexler pp. 14, 16, 18. Although
the addition of iron dust filings is considered treatment under 260.10, the Agency does not believe it
is adequate treatment under section 3004 (m); but merely the addition of material as a substitute for
adequate treatment, and therefore constitutes impermissible dilution. See 40 CFR 268.3 (b), 54 FR
at 48494 (November 1989), and 55 FR at 22532 (June 1, 1990).
The Agency is also codifying this determination by amending 40 CFR 268.3 to read as
follows:
40 CFR 268
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§ 268.3 Dilution prohibited as a substitute for treatment
* * *
(d) It is a form of impermissible dilution, and therefore prohibited, to add iron filings or other
metallic forms of iron to lead-containing hazardous wastes in order to achieve any land disposal
restriction treatment standard for lead. Lead-containing wastes include D008 wastes (wastes
exhibiting a characteristic due to the presence of lead), all characteristic wastes containing lead as an
underlying hazardous constituent, listed wastes containing lead as a regulated constituent, and
hazardous media containing any of the aforementioned lead-containing wastes.
* * *
With respect to the comment on lead species, EPA acknowledges the commenter's point that
lead species are different in the foundry product from that"of the lead in spent abrasive blasting
media. However, EPA does not believe that iron dust treatment of foundry sands is effective for
reasons described below. Because the waste foundry sand would likely contain only lead, silica,
microscopic pieces of castings, and binders (clays, phenols^ and tars) from the molds, EPA is not
convinced that the simple addition of iron would provide treatment for the lead or the organics (i.e.,
phenol and tar). While it may be argued that iron could form temporary and weak, ionic complexes
with silica and/or phenol, so that when analyzed by the TCLP test the lead appears to have been
stabilized; however, EPA believes that this "stabilization" is temporary, based upon the nature of the
complexing. In a report by EPA on Iron Chemistry in Lead Contaminated Materials (Feb. 22, 1994),
which specifically addressed this issue, EPA found that iron-lead bonds are weak, adsorptive, surface
bonds. EPA believes that these iron-lead bonds are not likely to be permanent. EPA continues to
believe that if this iron-rich mixture is exposed to moisture and oxidative conditions over time,
interstitial water would likely acidify, which could potentially reverse any temporary stabilization, as
well as increase the leachability of the lead from the foundry sand.
The commenter is correct in that the Battelle report did not state that the bonds are not
permanent, but concluded that the long-term stability is unknown. However, the Agency remains
unconvinced about the long-term stability of this technology. The Agency realizes that this
technology has been in use only since the early 1980's and thus, there is little data available on long-
term effectiveness. The Agency compiled information on two different studies conducted on this
issue, one by Dr. John Drexler of the University of Colorado and the other by Dr. Douglas Kendall
of the National Enforcement Investigation Center (NEIC). These studies found that even after
treatment, high concentrations of lead remained available to the environment and also leached in the
units receiving the spent foundry wastes. Therefore, these studies concluded that the addition of iron
filings or iron dust to lead-contaminated spent foundry sands did not constitute adequate treatment of
the waste. See the March 5, 1997 NODA (62 FR 10004) for a full discussion of these studies. The
conclusions reached by these studies were peer reviewed by an expert panel. The peer reviewers
agreed that adding iron filings to spent foundry sand is not treatment of hazardous constituents. The
peer reviewers also found that the scientific data presented in the studies support the conclusions
reached and the studies are based on sound scientific research and fact. Therefore, the Agency
reaffirms its conclusion that the addition of iron filing constitutes impermissible dilution
44
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Regarding the comment on foundry industry's practice of reclaiming foundry sand by thermal
oxidization of impurities, the Agency notes that this issue is outside the scope of this rulemaking.
This rulemaking only addresses the issues related to the addition of iron filings to spent foundry
waste as a method of treatment.
45
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Issue: FOUN1-050 Respondent: TTS
Den: PH3P050 Extension: CBI: N
Commenter: STEEL STRUCTURES PAINTING COUNCIL
Comment Number: 00001
//COMM1
//RESPTTS
//SUBJFOUN1-050
BACKGROUND
SSPC HAS IDENTIFIED LEAD PAINT REMOVAL AS A MAJOR ISSUE FOR OUR
MEMBERS. OUR ORGANIZATION HAS STRIVED TO IDENTIFY AND ESTABLISH COST
EFFECTIVE AND COMPLIANT TECHNIQUES AND STRATEGIES TO REMOVE LEAD
PAINT FROM INDUSTRIAL STRUCTURES. IN PARTICULAR, SSPC HAS UNDERTAKEN
MAJOR EFFORTS TO EDUCATE OUR MEMBERSHIP ON THE REQUIREMENTS FOR
PROPERLY HANDLING AND DISPOSING LEAD BEARING WASTE.
USE OF STEEL GRIT
THE TRADITIONAL MEANS OF REMOVING LEAD PAINT FROM INDUSTRIAL
STRUCTURES (E.G. BRIDGES, WATER TOWERS) INCLUDE USE OF NON-METALLIC,
EXPENDABLE ABRASIVES SUCH AS SILICA SAND, COAL SLAG AND COPPER SLAG.
THE ABRASIVE BLASTING OPERATION CREATES LARGE AMOUNTS OF DUST AND
DEBRIS. EVEN WITH ENVIRONMENTAL AND WORKER HEALTH AND SAFETY
CONTROLS AS MANDATED BY EPA AND OSHA, IT REMAINS THE MOST PRODUCTIVE
AND EFFECTIVE MEANS FOR REMOVING LEAD PAINT. ABRASIVE BLASTING
TYPICALLY USES 2-10 POUNDS OF ABRASIVES PER SQUARE FOOT OF SURFACE.
WITH SURFACES SPANNING HUNDREDS AND THOUSANDS OF SQUARE FEET, THE
AMOUNT OF WASTE IS OFTEN QUITE LARGE. IF THE WASTE IS HAZARDOUS, IT
MUST BE TREATED AND DISPOSED, THE COST POTENTIAL OF WHICH IS OFTEN VERY
HIGH.
USE OF RECYCLABLE STEEL GRIT
DURING THE PAST 5 TO 10 YEARS MANY OF THE PAINT REMOVAL FIRMS HAVE
CONVERTED TO USING RECYCLABLE STEEL ABRASIVES IN PLACE OF EXPENDABLE
ABRASIVES. STEEL GRIT AND STEEL SHOT CAN BE RECYCLED 50 OR MORE TIMES,
46
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RESULTING IN A 90%+ REDUCTION OF THE AMOUNT OF WASTE GENERATED. THIS
MEETS A KEY RCRA OBJECTIVE OF REDUCING THE AMOUNT OF WASTE PRODUCED.
THE MAJOR CHALLENGE IN THE USE OF RECYCLABLE STEEL ABRASIVE IS THE
COLLECTION OF THE ABRASIVE AFTER BLASTING AND REMOVING THE PAINT CHIPS
AND ABRASIVE FINES FROM THE AFFECTED ABRASIVE. THE INDUSTRY HAS
EXPENDED MAJOR RESOURCES IN DEVELOPING IMPROVED TECHNIQUES FOR THESE
OPERATIONS. MANY SSPC MEMBERS USE RECYCLABLE STEEL GRIT FOR REMOVING
LEAD PAINT FROM INDUSTRIAL STRUCTURES. WE BELIEVE THAT THIS PROCESS IS
CONSISTENT WITH THE INTENT AND SPIRIT OF RCRA. NOTE: STEEL ABRASIVE IS, BY
NO MEANS, A NEW MATERIAL FOR ABRASIVE BLAST CLEANING. RECYCLABLE
STEEL IS COMMONLY USED IN FABRICATING SHOPS TO REMOVE MILL SCALE FROM
HOT ROLLED STEEL PRIOR TO APPLYING THE COATING.
SSPC RECOMMENDATIONS
SSPC SUGGEST THE FOLLOWING LANGUAGE FOR A RULE:
WASTE, DEFINED AS SPENT ABRASIVE THAT IS NOT INTENDED FOR RECYCLING,
AND MEETING ALL THREE OF THE FOLLOWING REQUIREMENTS, SHALL REQUIRE
SPECIAL TREATMENT AS DEFINED BELOW:
l.THE WASTE IS GENERATED DURING BLAST CLEANING REMOVAL OF PAINT USING
ABRASIVES WITH 1% BY WEIGHT OR GREATER IRON OR STEEL GRIT OR SHOT;
2.THE WASTE GENERATED WHEN REMOVING PAINT CONTAINING 0.5% BY WEIGHT
OR MORE LEAD; AND
3.THE GENERATED WASTE CONTAINS 2% BY WEIGHT OR MORE IRON AS
DETERMINED BY AA OR ICP.
WASTE, AS DEFINED ABOVE AND MEETING THE THREE REQUIREMENTS LISTED
ABOVE, SHALL REQUIRE A PERMANENT STABILIZATION PROCESS BY AN EPA
APPROVED METHOD, SUCH AS TREATMENT WITH PORTLAND CEMENT.
NOTES:
A MINIMUM LEVEL OF 1% IRON OR STEEL GRIT HAS BEEN SELECTED FOR
CONDITION 1 FOR THE FOLLOWING REASON: AT TWO PERCENT (2%) ADDITION OF
IRON FILINGS TO LEAD WASTE, A NONHAZARDOUS WASTE WAS GENERATED (PRIOR
TO THE ADDITION OF THE IRON FILINGS THE WASTE HAD BEEN DETERMINED TO BE
HAZARDOUS BY THE TCLP TEST.). HOWEVER, AT 1% ADDITION OF IRON FILINGS,
THE WASTE CHARACTERISTIC WAS NOT CHANGED FROM HAZARDOUS TO
NONHAZARDOUS. THIS IS BASED ON DATA FROM A FHWA REPORT (FHWA-
RD-94-100).
A LEVEL OF 0.5% LEAD-IN-PAINT THRESHOLD HAS BEEN SELECTED BECAUSE THAT
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IS THE DEFINITION OF LEAD PAINT BEING USED BY EPA IN THE TITLE X
REGULATION (40 CFR 745, PROPOSED 9/2/94).
A LEVEL OF 2% HAS BEEN SELECTED FOR THE LEVEL OF IRON IN PAINT TO ALLOW
FOR THE PRESENCE OF IRON OXIDE (E.G. FROM RUST OR IRON OXIDE PIGMENTS IN
PAINT). THIS FORM OF IRON WOULD BE PRESENT IN ADDITION TO ANY RESIDUE
FROM THE METALLIC ABRASIVE USED FOR BLAST CLEANING.
PROPOSED MODIFICATION TO TCLP
AN ALTERNATIVE SUGGESTED BY SEVERAL OF OUR MEMBERS IS TO MODIFY THE
TCLP TEST AS FOLLOWS: MAGNETICALLY REMOVE THE METALLIC IRON PRIOR TO
RUNNING THE TCLP TEST. THIS WOULD PREVENT A "MASKING" OF THE TCLP TEST
BY THE REACTION BETWEEN METALLIC IRON AND LEAD. IF EPA CONSIDERS THIS A
REASONABLE APPROACH, SSPC WOULD MAKE AN EFFORT TO INITIATE A PROTOCOL
AND EVALUATION OF SUCH A TREATMENT. NOTE: SSPC LABORATORY
PERSONNEL HAVE PERFORMED SOME RELATED WORK WHICH INVOLVED USING
MAGNETS TO SEPARATE NON-MAGNETIC IMPURITIES FROM METALLIC ABRASIVES
AS PART OF A STANDARD ACCEPTANCE CRITERION.
SSPC BELIEVES THAT A RULE BASED ON THE ABOVE CRITERIA WILL BE
PROTECTIVE OF HUMAN HEALTH AND THE ENVIRONMENT AND CONSISTENT WITH
EPA"S GOALS. IN ADDITION, IT WILL ENABLE THE PROTECTIVE COATINGS
INDUSTRY TO CONTINUE TO USE A PROVEN PROCESS WHICH HAS RESULTED IN
SIGNIFICANT REDUCTION IN THE QUANTITY OF LEAD CONTAINING HAZARDOUS
WASTE GENERATED. THIS RULE WILL PERMIT THE INDUSTRY TO MEET THE GOALS
OF EPA WITHOUT SACRIFICING THE QUALITY, PRODUCTIVITY AND COST
EFFECTIVENESS OF THIS METHOD OF LEAD PAINT REMOVAL.
//ENDC1
RESPONSE
The Steel Structures Painting Council suggested the Agency propose specific language
(supplied by the commenter) as a rule for spent abrasive waste generated from lead paint removal
operations.
The Agency disagrees with the commenter's suggestion to specify compositions and criteria
of the as generated waste. EPA maintains that if the waste meets the definition of a toxiciry
characteristic hazardous waste, then it will be subject to the land disposal restrictions for the
particular characteristic waste (e.g., lead-D008). The commenter's suggestion would be tantamount
to "listing" a waste, and as such is beyond the scope of this land disposal restrictions rule. Further,
the suggestion to require a specific disposal method such as a permanent stabilization technology for
these spent abrasive wastes will preclude the use of other applicable and demonstrated technologies,
and hence, not provide treaters with maximum flexibility for selection of treatment./disposal options.
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EPA wishes to note that, should the commenter believe that their waste is unique to the extent that
the current treatment standards for characteristic waste is in appropriate, then they may petition the
Agency for a treatability variance as per 40 CFR 268.44 on a case-by-case basis.
EPA disagrees with the commenter's suggestion that EPA modify the TCLP analysis with
respect to these wastes whereby metallic iron could be magnetically removed prior to running the
TCLP test. The Agency notes that RCRA requires that the TCLP analysis for determination of TC
hazardousness be performed at the point of waste generation (55 FR 11830, March 29, 1990). The
modification the commenter suggests would result in treatment prior to analysis for TC
hazardousness.
49
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Issue: FOUN1-051 Respondent: TTS
Dcn:PH3P051 Extension: CBI:N
Commenter: RMT, INC
Comment Number: 00001
//COMM1
//RESPTTS
//SUB JFOUN1-051
RMT"S RESPONSE
FIRST, TREATMENT OF BRASS FOUNDRY SAND WITH IRON TO IMMOBILIZE LEAD IS
NOT DILUTION IN THE STANDARD USE OF THE TERM. TREATMENT TYPICALLY
INVOLVES THE ADDITION OF BETWEEN 1 AND 10 PERCENT METALLIC IRON. LEAD
CONCENTRATIONS IN THE TCLP TEST ARE REDUCED FROM HUNDREDS OF
MILLIGRAMS PER LITER (MG/L) TO LESS THAN 1 MG/L. THERE IS A CHEMICAL
REACTION OCCURRING WITH THE ADDITION OF THE IRON OTHERWISE THE
ADDITION OF 10% OF AN ADDITIVE COULD NOT REDUCE THE LEAD
CONCENTRATION BY A FACTOR OF OVER 100 DUE TO DILUTION ALONE. THE IRON
CLEARLY REACTS VERY STRONGLY WITH THE LEAD FOR SUCH A SMALL DOSAGE
TO REDUCE THE CONCENTRATION BY SUCH A LARGE FACTOR. METALLIC IRON IS
MORE EFFECTIVE AT STABILIZING LEAD THAN MOST OTHER TREATMENT
ADDITIVES INCLUDING THE ADDITIVES MOST COMMONLY USED AS
STABILIZATION/SOLIDIFICATION AGENTS, SUCH AS LIME OR CEMENT.
UNDERSTANDING THE CHEMISTRY OF THE REACTION BETWEEN THE LEAD AND
IRON BECOMES KEY TO DISCUSSING WHETHER THE TREATMENT PROCESS IS A
VIABLE STABILIZATION OR IS SIMPLY "MASKING" THE LEAD IN THE TCLP TEST. IF
IT IS SIMPLY MASKING THE LEAD WITHOUT A REAL STABILIZATION OCCURRING,
WHICH WOULD PROTECT LEAD FROM LEACHING IN THE REAL WORLD, IT WOULD
BE CONSIDERED AN "IMPERMISSIBLE DILUTION" UNDER THE EPA"S DEFINITION.
A. METALLIC IRON DOES NOT REACT WITH LEAD; THEREFORE, IT IS AN
IMPERMISSIBLE DILUTION.
THE EPA"S POSITION STATED IN THE FEDERAL REGISTER IS THAT "IRON COULD
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FORM TEMPORARY, WEAK, IONIC COMPLEXES WITH SILICA AND/OR PHENATE, SO
THAT WHEN ANALYZED BY THE TCLP TEST THE LEAD APPEARS TO HAVE BEEN
STABILIZED, THE AGENCY BELIEVES THIS "STABILIZATION" IS TEMPORARY, BASED
UPON THE NATURE OF THE COMPLEXING. IN FACT, A REPORT PREPARED BY THE
EPA IN IRON CHEMISTRY OF LEAD CONTAMINATED MATERIALS (FEE 22, 1994),
WHICH SPECIFICALLY ADDRESSED THIS ISSUE, FOUND THAT IRON-LEAD BONDS
ARE WEAK, ADSORPTIVE SURFACE BONDS, AND THEREFORE NOT LIKELY TO BE
PERMANENT."
FIRST, THE EPA"S STATEMENT QUOTED ABOVE MAKES NO TECHNICAL SENSE
WITHOUT FURTHER EXPLANATION. EVEN ASSUMING THAT IRON DOES FORM WEAK
COMPLEXES WITH SILICA OR PHENOL, WHAT INFLUENCE DOES SUCH A REACTION
HAVE ON THE LEACHING BEHAVIOR OF LEAD IN A TCLP TEST? IS LEAD
SUPPOSEDLY TRAPPED IN THE COMPLEX? IF SO, HOW CAN SO WEAK A COMPLEX SO
STRONGLY IMMOBILIZE LEAD IN A TCLP TEST? THE RELATIONSHIP OF THE WEAK
COMPLEX BETWEEN IRON AND SILICA OR PHENOL AND LEAD LEACHING IS NOT
EXPLAINED.
MOREOVER, THE EPA"S POSITION IS NOT SUPPORTED BY THE BACKGROUND
REPORT CITED IN THE FEDERAL REGISTER. THE REPORT MENTIONED IS A COVER
MEMO ON A REPORT BY THE COLUMBUS, OHIO, OFFICE OF BATTELLE INC. TITLED
"SUMMARY OF DATA ANALYSIS AND EXPERIMENTAL DESIGN FOR INVESTIGATION
OF IRON CHEMISTRY IN LEAD CONTAMINATED MATERIALS (JANUARY, 1994)."
THERE IS NO MENTION OF A REACTION BETWEEN IRON AND SILICA OR PHENOL IN
THE BATTELLE REPORT. THE BATTELLE STUDY INCLUDES A LITERATURE REVIEW
AND THERMODYNAMIC MODELING OF THE REACTION BETWEEN IRON AND LEAD IN
BRASS FOUNDRY SAND TREATMENT. THERE ARE NO NEW DATA PRESENTED IN THE
BATTELLE REPORT. THE STUDY FINDS THAT THERE ARE TWO REACTION
MECHANISMS THAT MAY IMMOBILIZE LEAD: AN OXIDATION-REDUCTION
REACTION BETWEEN METALLIC IRON AND DISSOLVED LEAD, AND AN ADSORPTION
REACTION BETWEEN FERRIC HYDROXIDE (OR MORE TECHNICALLY HYDROUS
FERRIC OXIDE) AND DISSOLVED LEAD. SINCE METALLIC IRON IS ADDED DURING
THE TREATMENT PROCESS, IT IS CLEARLY THE REDOX REACTION THAT IS
IMMOBILIZING LEAD DURING THE TCLP TEST. THIS SAME CONCLUSION HAS BEEN
FOUND BY ALL OF THE OTHERS WHO HAVE INVESTIGATED THE REACTION (NAGEL,
ET AL., 1983; STEPHENS, ET AL., 1984; OSTROM AND TROJAN, 1988; SMITH, ET AL.,
1991). THE REACTION BETWEEN HYDROUS FERRIC OXIDES AND LEAD HAS BEEN
FOUND TO BE EFFECTIVE IN SOME CASES (OSTROM AND TROJAN, 1988) BUT NOT IN
OTHERS (OSTROM ET AL., 1985). THE REACTION MECHANISM FOR THE
STABILIZATION REACTION IS THEREFORE A REDOX REACTION, IN WHICH THE
METALLIC IRON REDUCES DIVALENT LEAD TO THE METALLIC FORM AND IS ITSELF
OXIDIZED, I.E.
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FEO + PB2+ =FE2+ + PBO
THE REACTION BETWEEN METALLIC IRON AND DISSOLVED METALS IS WELL
KNOWN. THERE IS A WASTEWATER TREATMENT PROCESS, IRON CEMENTATION,
THAT USES METALLIC IRON TO REMOVE HEAVY METALS (E.G. COPPER, LEAD) FROM
A WASTEWATER (AGELIDIS, ET AL., 1988; KU AND CHEN, 1992). IN ADDITION,
STANDARD INTRODUCTORY CHEMICAL TEXTBOOKS DISCUSS THE OXIDATION-
REDUCTION (REDOX) REACTION BETWEEN IRON AND OTHER METALS (E.G., SIENKO
AND PLANE, 1966). THIS REDOX REACTION WOULD OCCUR IN A LANDFILL IN THE
PRESENCE OF IRON IF LEAD WERE SOLUBILIZED FROM THE WASTE MATERIAL, AND
IT OCCURS IN THE TCLP TEST.
THE EPA"S SUGGESTION THAT IRON FORMS "TEMPORARY, WEAK, IONIC
COMPLEXES WITH SILICA AND/OR PHENATE" INDICATES THAT THEY DO NOT
UNDERSTAND THE REACTION CHEMISTRY THAT HAS BEEN PRESENTED IN THE
DOCUMENT THAT THEY CITE AS SUPPORTING THEIR POSITION. THE EPA"S POSITION
THAT THERE IS NO REACTION BETWEEN IRON AND LEAD IS CONTRADICTED BY
THEIR OWN REFERENCE, AS WELL AS BY THE OTHER RESEARCHERS ON THE
SUBJECT. A SEPARATE QUESTION IS APPROPRIATE AS TO THE LONG-TERM
EFFECTIVENESS OF IRON TREATMENT, BUT TO CLAIM THE REACTION DOES NOT
OCCUR IS SIMPLY INCORRECT.
B. ACID FORMATION IN LANDFILLS
THE EPA"S SECOND REASON FOR PROPOSING TO BAN THE USE OF METALLIC IRON IS
THAT THE IRON MAY GENERATE ACID CONDITIONS IN A LANDFILL. HOWEVER, THE
EPA GIVES NO SUPPORTING DOCUMENTATION FOR THIS ASSERTION. THERE IS NO
OBVIOUS BASIS FOR THE ASSERTION, AND IT IS CONTRARY TO EXPERIENCE THAT
METALLIC IRON WILL GENERATE ACID CONDITIONS.
ACIDIC CONDITIONS CAN BE GENERATED FROM SOME FORMS OF IRON,
PARTICULARLY FROM THE OXIDATION OF FERROUS SULFIDE (PYRITE) AS OCCURS
IN ACID MINE DRAINAGE, OR FROM THE HYDROLYSIS OF FERRIC IRON TO FORM
FERRIC HYDROXIDE AS OCCURS DURING WASTEWATER TREATMENT WITH FERRIC
SALTS. NEITHER OF THESE SITUATIONS OCCURS IN THE SCENARIO WHEN
METALLIC IRON IS USED FOR TREATING BRASS FOUNDRY WASTES. METALLIC
IRON, IN FACT, WILL REACT WITH ACIDS TO GENERATE HYDROGEN GAS, AND IN
THE PROCESS, WILL NEUTRALIZE THE ACID, I.E.
FEO + 2 H+ = FE2+ + H2
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THE EVOLUTION OF HYDROGEN GAS WHEN METALS ARE ADDED TO AN ACIDIC
SOLUTION IS A WELL-KNOWN PHENOMENON. AS AN EXAMPLE, IRON USED TO
TREAT FOUNDRY WASTES WILL FREQUENTLY NEUTRALIZE THE ACETIC ACID USED
IN THE TCLP TEST AND RAISE THE PH ABOVE 5. FOR THE EPA TO SUGGEST THAT
METALLIC IRON WILL GENERATE ACIDS IS SIMPLY CONTRARY TO EXPERIENCE AND
BASIC CHEMISTRY.
FURTHERMORE, IF METALLIC IRON IN THE ENVIRONMENT GENERATED ACIDS,
THEN ONE WOULD EXPECT TO FIND ACIDIC LEACHATES ARISING FROM SITUATIONS
WHERE METALLIC IRON OCCURRED OR WAS DISPOSED IN THE ENVIRONMENT. IRON
FOUNDRY LANDFILLS OFTEN CONTAIN SIGNIFICANT AMOUNTS OF METALLIC IRON,
EITHER IN THE FORM OF METAL GRINDING WASTES OR AS WASTE FROM THE
MELTING AND CASTING PROCESS. THESE LANDFILLS DO NOT BECOME ACIDIC
OVER TIME, NOR DO THE WASTES APPEAR TO CONTRIBUTE HYDROGEN ION TO THE
GROUND WATER (HAM, ET AL., 1985). IF METALLIC IRON IN LANDFILLS GENERATED
ACIDIC CONDITIONS, THEN ONE WOULD EXPECT THAT THE MANY IRON FOUNDRY
LANDFILLS THROUGHOUT THE COUNTRY WOULD BE EXPERIENCING
ENVIRONMENTAL PROBLEMS DUE TO ACID GENERATION. THIS IS SIMPLY NOT THE
CASE.
ONE OF THE MORE INTERESTING APPLICATIONS OF METALLIC IRON FOR
ADDRESSING ENVIRONMENTAL PROBLEMS IS IN THE USE OF REACTION WALLS
BUILT INTO THE SOIL FOR THE DEHALOGENATION OF CHLORINATED SOLVENTS IN
GROUND WATER. AT A SYMPOSIUM ENTITLED "CONTAMINANT REMEDIATION WITH
ZERO-VALENT METALS" HELD AT THE 209TH AMERICAN CHEMICAL SOCIETY'S
NATIONAL MEETING IN ANAHEIM, CALIFORNIA (APRIL 2-7, 1995), THIRTY-THREE
PAPERS WERE PRESENTED ON THE USE OF METALLIC IRON FOR THE DESTRUCTION
OF ORGANIC COMPOUNDS. IF METALLIC IRON GENERATED ACID IN SUBSURFACE
CONDITIONS, THEN SURELY THE ISSUE WOULD BE OF MAJOR CONCERN IN THESE
PAPERS. IF THE ACID GENERATION POTENTIAL FROM METALLIC IRON USED TO
TREAT FOUNDRY WASTES IS OF SUFFICIENT CONCERN TO BAN THE PROCESS, THEN
THE POSSIBILITY OF ACID GENERATION FROM THE METALLIC IRON REACTION
WALLS WOULD BE EXPECTED TO BE OF SUFFICIENT CONCERN FOR THIS PROCESS.
HOWEVER, THE POSSIBILITY OF ACID FORMATION FROM THE USE OF IRON WAS NOT
MENTIONED IN THE ABSTRACTS.
AGAIN, THE EPA IN THEIR PRESENTATION IN THE FEDERAL REGISTER DOES NOT
UNDERSTAND THE CHEMISTRY OF IRON IN FOUNDRY WASTES, AND
MISREPRESENTS THE ACTUAL REACTIONS.
C. IRON INTERFERES WITH LEAD ANALYSIS IN TCLP TEST LEACHATES, THEREBY
GENERATING FALSE NEGATIVES
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THE EPA ASSERTS THAT METALLIC IRON INTERFERES WITH THE ANALYSIS OF IRON
IN TCLP TEST LEACHATES. THE CITATION IN THE FEDERAL REGISTER IS A LETTER
FROM JOHN CIGNATTA, OF DATANET, TO JOHN GAUTHIER OF REGION I, EPA. THE
LETTER CITES MS. GAIL HANSEN, OF THE EPA OFFICE OF SOLID WASTE, FOR THE
ASSERTION THAT METALLIC IRON INTERFERES WITH THE ANALYSIS OF LEAD IN
TCLP TEST LEACHATES. MR. CIGNATTA STATES THAT "ACCORDING TO MS. GAIL
HANSEN OF EPA OFFICE OF SOLID WASTE, THE PRESENCE OF IRON MAKES THE TCLP
TEST QUITE IMPRACTICAL AS ESTABLISHED BY SPIKED SAMPLES HAVING
EXCEEDINGLY POOR RECOVERY RATES." WHEN FIRST ASKED ABOUT MR.
CIGNATTA"S STATEMENT, MS. HANSEN SAID THAT SHE DID NOT RECALL MAKING
THIS STATEMENT. UPON SEVERAL DAYS REFLECTION, HOWEVER, MS. HANSEN
VAGUELY RECALLED A REPORT BY AN OUTSIDE LABORATORY THAT MAY HAVE
INDICATED AN ANALYTICAL INTERFERENCE BETWEEN IRON AND LEAD. SHE
COULD NOT LOCATE THE REPORT, AND DOES NOT RECALL SPECIFICALLY WHAT
LABORATORY WROTE THE REPORT, OR THE DETAILS OF THE INTEREFERENCE.
SINCE THE REPORT IS NOT AVAILABLE FOR REVIEW, IT IS DIFFICULT TO DETERMINE
ON WHAT BASIS THE CLAIM WAS MADE AS TO THE INTEREFERENCE. OLLIE
FORDHAM, NATIONAL PROGRAM MANAGER FOR INORGANIC SW846 ANALYSIS,
STATED THAT THERE IS NO ANALYTICAL INTEREFERENCE IN THE AA OR ICP
ANALYSIS BETWEEN IRON AND LEAD AFTER THE TCLP TEST LEACHATE IS
FILTERED UNLESS THE IRON IS PRESENT IN HIGH CONCENTRATIONS (ABOVE A
THOUSANDS MG/L). AS A PRACTICAL MATTER, IF IRON DID INTEREFERE WITH THE
ANALYSIS OF LEAD IN TCLP TEST LEACHATES, THEN EVERY LABORATORY IN THE
COUNTRY THAT RUNS IRON-TREATED MATERIALS SHOULD BE REPORTING THE
FACT, SINCE SPIKING TCLP TEST LEACHATES IS PART OF THE STANDARD QC
PROTOCOL FOR TCLP TEST. AS ONE EXAMPLE, THE RMT LABORATORY DOES NOT
HAVE ANY DIFFICULTY IN OBTAINING EXCELLENT SPIKE RECOVERIES FROM TCLP
TEST LEACHATES OF IRON TREATED WASTES. SINCE THERE IS NO
DOCUMENTATION OF A PROBLEM IN THE ANALYSIS OF LEAD IN TCLP LEACHATES
FROM IRON TREATED WASTES, AND SINCE THE RMT LABORATORY HAS NEVER
ENCOUNTERED ANY DIFFICULTIES, OUR CONCLUSION IS THAT THERE IS NO
PROBLEM WITH THE ANALYSIS.
IN SUMMARY, ALL OF THE TECHNICAL ARGUMENTS THAT THE EPA PRESENTS FOR
JUSTIFYING BANNING THE USE OF METALLIC IRON ARE NOT TRUE AND ARE NOT
SUPPORTED BY THE BACKGROUND DOCUMENTATION PRESENTED BY THE EPA.
OTHER CONCERNS ABOUT IRON TREATMENT
THERE ARE CONCERNS THAT ARE IMPLIED BUT NOT DIRECTLY STATED BY THE EPA
ABOUT THE USE OF METALLIC IRON FOR TREATING WASTES. THESE ISSUES HAVE
BEEN RAISED AT LEAST IN PART BY SOME OF THE AUTHORS WHO DISCUSS IRON
TREATMENT, PARTICULARLY SMITH ET AL.(1991). THE CONCERNS ABOUT IRON
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TREATMENT ARE TWOFOLD, AS FOLLOWS:
NO REACTION OCCURS WHEN IRON IS ADDED TO WASTE, AND THE TREATMENT IS
THUS "MASKING" LEAD IN THE TCLP TEST. FURTHERMORE, THE ADDITIVE AND
WASTE COULD SEPARATE DURING TRANSPORT.
FIRST, THERE IS NO REACTION BETWEEN LEAD AND ANY DRY ADDITIVE, BE IT
LIME, CKD, PORTLAND CEMENT, OR METALLIC IRON. THE REACTIONS DO NOT
OCCUR UNTIL THE SAMPLE GETS WET. THE ARGUMENT THAT IRON IS NOT
EFFECTIVE COULD EQUALLY WELL BE APPLIED TO ANY DRY ADDITIVE. LEAD WILL
NOT LEACH FROM THE WASTE UNTIL THE WASTE GETS WET, SO THAT THE
CONCERN ABOUT NO REACTION OCCURRING UNTIL THE SAMPLE IS WETTED IS
IRRELEVANT, PROVIDED THAT THE WASTE AND ADDITIVE DO NOT SEPARATE
PRIOR TO WETTING.
<
IT IS UP TO THE GENERATOR TO ENSURE GOOD MIXING BETWEEN THE WASTE AND
ADDITIVE, NO MATTER WHAT TYPE OF ADDITIVE IS USED. THE EPA SHOULD NOT
BAN A PROCESS BECAUSE THEY ARE CONCERNED ABOUT MIXING EFFECTIVENESS.
IRON MAY OXIDIZE IN A LANDFILL AND THUS NOT PROVIDE REAL
LONG-TERM TREATMENT
THE CONCERN THAT IRON USED FOR TREATMENT WILL OXIDIZE AFTER DISPOSAL
AND THEREFORE NOT PROVIDE LONG-TERM TREATMENT FOR THE WASTE, WILL
NOT OCCUR FOR A BRASS FOUNDRY WASTE. IN ORDER TO OXIDIZE THE IRON, AN
OXIDIZING AGENT IS REQUIRED. SINCE THE IRON CONSTITUTES ABOUT 10 PERCENT
OF THE WASTE, THE OXIDIZING AGENT HAS TO BE PRESENT AT A SUFFICIENT
CONCENTRATION TO OXIDIZE THE LARGE AMOUNT OF IRON. THE MOST COMMON
OXIDIZING AGENT IS, OF COURSE, ATMOSPHERIC OXYGEN. HOWEVER, THE WASTE
IS EFFECTIVELY ISOLATED FROM THE AIR WHEN IT IS PLACED IN A LANDFILL. IN
ORDER TO MOVE SUFFICIENT OXYGEN INTO THE LANDFILL TO OXIDIZE THE IRON,
SEVERAL HUNDRED PORE VOLUMES OF AIR WOULD BE REQUIRED TO PASS
THROUGH THE WASTE. SINCE THERE IS NO MAJOR DRIVING FORCE FOR THE AIR TO
MOVE IN OR OUT OF THE LANDFILL, THE LARGE VOLUMES OF AIR REQUIRED TO
OXIDIZE THE IRON WILL NOT PASS THROUGH THE LANDFILL. THE METALLIC IRON
ESTABLISHES AND MAINTAINS ANOXIC CONDITIONS IN THE LANDFILL.
MODELING LONG-TERM LEACHING
THE EPA HAS ESTABLISHED THE MULTIPLE EXTRACTION PROCEDURE (MEP) (SW846
METHOD 131) TO MODEL THE LONG-TERM LEACHING POTENTIAL OF WASTES. IF
IRON-TREATED WASTES WERE NOT STABLE, THEN THE TREATED WASTES SHOULD
NOT BE STABLE IN AN MEP TEST. HOWEVER, SUCH IS NOT THE CASE. THE RESULTS
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OF AN MEP TEST CONDUCTED ON AN IRON-TREATED BRASS FOUNDRY SAND ARE
PRESENTED IN TABLE 1. THE TEST WAS CONDUCTED AS PART OF A SUBMITTAL TO
REGION V OF THE EPA, AND WAS ACCOMPANIED BY THE FULL QC PACKAGE. AS
CAN BE SEEN, THE IRON-TREATED WASTE DID NOT LEACH LEAD ABOVE THE
DETECTION LIMIT IN ANY OF THE TEN ELUTIONS. IF IRON WERE EASILY OXIDIZED,
THEN ONE WOULD EXPECT IT TO BE OXIDIZED IN THE MEP TEST, AND ONE WOULD
LIKEWISE EXPECT THE TEST RESULTS TO DEMONSTRATE THE FAILURE OF THE
TREATMENT.
FURTHERMORE, CASE STUDIES ON BRASS FOUNDRY LANDFILLS IN WHICH IRON
TREATMENT HAS BEEN EMPLOYED HAVE NOT SHOWN PROBLEMS DUE TO
OXIDATION OF THE IRON. THESE CASE STUDIES ARE PRESENTED IN THE
SUBMITTAL FROM THE AMERICAN FOUNDRYMENS SOCIETY ON THE SAME ISSUE.
THUS, THERE IS NO EVIDENCE, EITHER FROM LEACHING TESTS OR FROM REAL-
WORLD EXPERIENCE, THAT IRON TREATMENT IS NOT A SUCCESSFUL LONG-TERM
TREATMENT FOR BRASS FOUNDRY SAND, WHEN THE TREATMENT IS CONDUCTED
IN AN APPROPRIATE MANNER.
IRON VS. LIME TREATMENT
TREATMENT WITH METALLIC IRON PARALLELS IN MANY ASPECTS TREATMENT
WITH A LIME-BASED ADDITIVE, SUCH AS LIME ITSELF OR CEMENT KILN DUST (CKD)
BOTH COMMONLY USED TREATMENT ADDITIVES. WHILE IRON REACTS WITH LEAD
TO FORM LEAD METAL, LIME SIMPLY MAINTAINS THE PH OF THE LEACHING TESTS
IN A REGION WHERE LEAD OXIDE/HYDROXIDE IS NOT SOLUBLE. LIME OR A LIME-
BASED ADDITIVE DOES NOT REACT DIRECTLY WITH THE LEAD IN THE WASTE TO
FORM AN INSOLUBLE PRECIPITATE. (THE ARGUMENT THAT LIME CONVERTS THE
LEAD TO A LEAD OXIDE OR HYDROXIDE IS NOT RELEVANT, SINCE BOTH
COMPOUNDS ARE QUITE SOLUBLE AT PH 5, THE NOMINAL PH OF THE TCLP TEST
AND SO IF THE PH OF THE TCLP TEST WERE NOT RAISED BY THE LIME TO A RANGE
WHERE LEAD IS NOT SOLUBLE, THE WASTE WOULD STILL BE HAZARDOUS. IN
ADDITION, LEAD IN THE ENVIRONMENT WILL CONVERT TO AN OXIDE OR
HYDROXIDE IF IT EXISTS IN A MORE SOLUBLE FORM TO START WITH. THEREFORE
TO STATE THAT LIME "CONVERTS" THE LEAD TO AN OXIDE FORM IS NOT
TECHNICALLY CORRECT.) IN THE SAME MANNER THAT CONCERNS CAN BE RAISED
ABOUT IRON OXIDIZING, LIME MAY BE LEACHED OUT A WASTE, LEAVING BEHIND
AN "UNTREATED" WASTE THAT WOULD FAIL A TCLP TEST IF THE WASTE WERE
RETESTED.
ACTUALLY, IRON TREATMENT MAY BE SUPERIOR TO LIME TREATMENT. LIME IS A
VERY CAUSTIC MATERIAL, AND DURING TREATMENT WILL RAISE THE PH OF THE
TREATED MATERIAL TO ROUND 12.5 THE TCLP TEST USES A STRONGLY BUFFERED
56
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ACID SOLUTION (0.1M ACETATE). SUCH HIGH BUFFERING CAPACITY IS NOT
NORMALLY ENCOUNTERED IN FOUNDRY WASTE LANDFILLS, SINCE THERE IS NO
DEGRADING ORGANIC MATTER TO GENERATE THE VOLATILE ORGANIC ACIDS.
RATHER THE LEACHING SOLUTION IN FOUNDRY WASTE LANDFILLS IS LIKELY TO
BE SIMILAR TO THE SYNTHETIC ACID RAIN USED IN THE SYNTHETIC PRECIPITATION
LEACHING PROCEDURE (SPLP - SW 846 METHOD 1312). IF SUFFICIENT LIME IS ADDED
TO A WASTE TO NEUTRALIZE THE ACID IN THE TCLP TEST AND BRING THE PH TO
THE RANGE WHERE LEAD IS NOT SOLUBLE IN THE TCLP TEST LEACHATE, THEN THE
LIME WILL RAISE THE PH OF AN SPLP TEST LEACHATE TO AROUND 12.5 (THE PH OF
A LIME-SATURATED SOLUTION). LEAD IS AN AMPHOTERIC METAL, AND IS SOLUBLE
UNDER BOTH ACIDIC AND BASIC PH CONDITIONS. AT A PH OF 12.5, DISSOLVED
LEAD CONCENTRATION IN SOLUTION CAN REACH TENS OF MG/L. THE USE OF LIME
TO REDUCE LEACHING IN A TCLP TEST MAY RESULT IN THE TREATED WASTE
LEACHING HIGH CONCENTRATIONS OF LEAD IN AN SPLP TEST, OR IN THE NATURAL
ENVIRONMENT. IRON TREATMENT, ON THE OTHER HAND, HAS NO SUCH
CONCERNS. LEAD IS NOT "AMPHOTERIC" ON A REDOX SCALE-IT DOES NOT GO
BACK INTO SOLUTION AS THE REDOX POTENTIAL IS LOWERED PAST A CERTAIN
POINT.
A DEMONSTRATION OF THIS DIFFERENCE IS GIVEN IN TABLE 2. SPLP TESTS WERE
RUN ON A SAMPLE OF BRASS FOUNDRY SAND TREATED WITH BOTH METALLIC
IRON (60%) AND LIME (6%). THE UNTREATED FOUNDRY SAND LEACHED LEAD AT
400 MG/L IN A TCLP TEST. IN AN SPLP TEST ON THE TREATED WASTE SAMPLES, THE
IRON-TREATED WASTE GAVE A LEAD CONCENTRATION IN THE SPLP LEACHATE OF
< 0.003 MG/L, WHILE THE LIME-TREATED WASTE GENERATED A LEAD
CONCENTRATION OF 23 MG/L. THE LIME HAS RAISED THE PH OF THE SPLP TEST
LEACHATE TO THE POINT WHERE LEAD IS RESOLUBILIZED, WHILE THE IRON
EFFECTIVELY STABILIZES THE LEAD IN THE WASTE TO VERY LOW LEVELS DURING
THE TEST. IRON TREATMENT IS CLEARLY SUPERIOR TO LIME TREATMENT FOR THIS
WASTE (A TYPICAL BRASS FOUNDRY SAND).
TO FURTHER DEMONSTRATE THE COMPARISON BETWEEN LIME AND IRON, MEP
LEACHING TESTS WERE CONDUCTED ON THE SAMPLE OF BRASS FOUNDRY SAND
TREATED WITH BOTH IRON (10% DOSE) AND LIME (6% DOSE). THIS TESTING IS STILL
UNDERWAY, AND THE COMPLETE RESULTS WILL BE PROVIDED TO EPA.
APPROPRIATE LEACHING TEST FOR FOUNDRY WASTES GOING TO A
MONOFILL IS THE SPLP TEST
THE EPA REQUESTED THAT SUBMITTERS RECOMMEND A MORE APPROPRIATE
LEACHING TEST FOR BRASS FOUNDRY SAND THAN THE TCLP TEST. WE
RECOMMEND THAT THE SPLP TEST BE USED FOR EVALUATING THE LEACHING
POTENTIAL OF FOUNDRY WASTES GOING TO NON-MUNICIPAL ONLY LANDFILLS,
57
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INCLUDING FOUNDRY WASTE"ONLY LANDFILLS. THE ACETIC ACID USED IN THE
TCLP TEST MODELS THE ACID GENERATED DURING THE FACULTATIVE
DECOMPOSITION STAGE OF A MUNICIPAL LANDFILL. LEACHATES FROM THIS STAGE
OF THE LANDFILL DECOMPOSITION MAY CONTAIN HIGH CONCENTRATIONS OF
VOLATILE ORGANIC ACIDS, SUCH AS ACETIC ACID, FROM THE DECOMPOSITION OF
ORGANIC MATERIALS PLACED IN THE LANDFILL. HOWEVER, FOUNDRY
WASTE"ONLY LANDFILLS DO NOT CONTAIN LARGE AMOUNTS OF PUTRESCIBLE
ORGANIC MATTER, AND THEREFORE DO NOT GENERATE LEACHATES WITH HIGH
CONCENTRATIONS OF VOLATILE ORGANIC ACIDS. FOUNDRY WASTE LANDFILLS
TEND TO HAVE BASIC RATHER THAN ACIDIC PH VALUES (HAM, ET AL.).
THEREFORE, A TEST THAT USES A HIGHLY ORGANIC ACID LEACHING SOLUTION
DOES NOT PROVIDE A REALISTIC EVALUATION OF THE LEACHING ENVIRONMENT
OF A FOUNDRY WASTE LANDFILL, OR OF MANY OTHER WASTE DISPOSAL
CONDITIONS EITHER. THE SPLP TEST USES A SYNTHETIC ACID RAIN AS A LEACHING
MEDIUM, AND PROVIDES A LEACHING SOLUTION'THAT IS FAR MORE REALISTIC
THAN THE ACETIC ACID USED IN THE TCLP TEST. AS DISCUSSED ABOVE FOR THE
COMPARISON BETWEEN LIME AND IRON TREATMENT, THERE MAY BE SITUATIONS
WHERE A WASTE TREATMENT PROCESS EFFECTIVELY IMMOBILIZES LEAD IN THE
TCLP TEST, BUT INCREASES THE LEACHING POTENTIAL OF LEAD IN THE MORE
REALISTIC SPLP TEST (E.G., LIME TREATMENT). SUCH A TREATMENT PROCESS
SOLVES A REGULATORY PROBLEM, BUT MAY CREATE A REAL ENVIRONMENTAL
PROBLEM. USE OF THE SPLP TEST FOR EVALUATING THE LEACHING POTENTIAL OF
WASTES IN FOUNDRY WASTE-ONLY LANDFILLS WOULD PROVIDE A MUCH MORE
REALISTIC VIEW OF THE LEACHING POTENTIAL OF THE WASTE. USE OF THE SPLP
TEST, OR A SIMILAR WATER LEACHING TEST HAS BEEN PROPOSED BY OTHERS
(HAM, ET AL., 1979). WE WOULD STRONGLY SUPPORT THE USE OF THE SPLP TEST AS
AN ALTERNATIVE OR A COMPLEMENT TO THE TCLP TEST FOR EVALUATING THE
LEACHING POTENTIAL OF FOUNDRY WASTES.
//ENDC1
RESPONSE
RMT, Inc., submitted comments objecting to EPA's position against addition of iron dust to
foundry sand. The main points raised by RMT, Inc. were:
1. Iron addition to foundry sand is not dilution as EPA categorizes the process;
2. Iron addition to foundry sand will not create acidic conditions in landfills;
3. Iron addition to foundry sand will not mask lead analysis in TCLP testing;
4. The iron added to the foundry sand will not separate out during transport;
5. Landfill conditions will not allow the iron to oxidize to the extent that long-term stability will
be adversely impacted;
58
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6. Iron treatment is more effective at treating the foundry sands than pozzolonic treatment; and
7. The SPLP leach test is a more appropriate test than TCLP for foundry wastes going into a
monofill.
The Agency's determination that the addition of iron filing constitutes impermissible dilution
is predicated on the fact that the adsorption of soluble lead on to the iron surface is a reversible
reaction and once the iron surfaces oxidize, the ability of the additive to scavenge soluble metals is
diminished. Therefore, the treatment is not permanent. In addition, adsorption alone is not a reliable
method of permanently immobilizing lead. The longevity of treatment cannot be measured by the
TCLP test, which provides only a snapshot of the leachable constituents under the test condition at
the time of analysis.
The commenter is correct in that the Battelle report did not state that the bonds are not
permanent, but concluded that the long-term stability is unknown. However, the Agency remains
unconvinced about the long-term stability of this technology. The Agency realizes that this
technology has been in use only since the early 1980's and thus, there is little data available on long-
term effectiveness. Recent studies conducted by Dr. Drexler, concluded that the addition of iron
filings changes the leaching fluids characteristics by increasing the pH and lowering Eh and DO to
levels that are unlike most natural environments wherre the wastes would be disposed (e.g., an
environment where iron is constantly added to the landfill). The study found that the increase in pH
(lowering of hydrogen ion activity) alone will lower the solubility of Pb in the test and insure a
greater frequency of "passes." The Agency infers from this that the immediate test conditions would
not be representative of the long-term landfill conditions. In the actual landfill, oxygen would defuse
in to oxidize the metal filings increasing Eh and DO, decreasing pH. This would act to remove the
initial adsorption of lead on the iron filings and results in leaching toxic levels of lead into the
environment. This is evident from the TCLP tests done on waste sand from the Nacogdoches
landfill that showed lead concentrations in the extracts ranging from 2.81 mg/1 to 11.6 mg/1.
Therefore, the addition of filings gives but a temporary effect unlike the long lasting effects obtained
through microencapsulation or other true treatment technologies which substantially reduce metal
mobility.
The Agency continues to believe that this treatment should be classified as impermissible
dilution. The Agency has concluded that this form of stabilization is inadequate to minimize the
threats posed by land disposal of metal-containing hazardous wastes. EPA, therefore considers this
technology "impermissible dilution" in accordance with 40 CFR 268.3. Although the addition of
iron dust filings is considered treatment under 260. 1 0, the Agency does not believe it is adequate
treatment; but merely the addition of material as a substitute for adequate treatment and therefore
constitutes impermissible dilution. See 40 CFR 268.3 (b), 54 FR at 48494 (November 1989), and 55
FR at 22532 (June 1,1990).
The Agency is codifying this determination by amending 40 CFR 268.3 to read as follows:
59
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40 CFR 268
§ 268.3 Dilution prohibited as a substitute for treatment
* * *
(d) It is a form of impermissible dilution, and therefore prohibited, to add iron filings or other
metallic forms of iron to lead-containing hazardous wastes in order to achieve any land disposal
restriction treatment standard for lead. Lead-containing wastes include D008 wastes (wastes
exhibiting a characteristic due to the presence of lead), all characteristic wastes containing lead as an
underlying hazardous constituent, listed wastes containing lead as a regulated constituent, and
hazardous media containing any of the aforementioned lead-containing wastes.
* *
The Agency does not agree with the commenter's suggestion that an alternative analytical
testing procedure be used since the waste is disposed of in" a monofill. EPA has established the
TCLP as the official required method for determining whether a waste is toxicity characteristic
hazardous. EPA's determination of the use of the TCLP was finalized on March 29, 1990 (55 FR
11798). This issue is not being reopened in this rulemaking. However, should this comment be
deemed to require a response, EPA reviewed the suitability for testing the leachability of lead in
foundry sand and continues to believe that TCLP testing is appropriate for determining the
characteristic of hazardousness for metal-bearing waste streams. This issue is further discussed in
the Technical Memorandum entitled "Iron Dust Treatment of Lead-Bearing Foundry Sand," dated
September 15, 1995, and can be found in the Administrative Record for this rulemaking.
60
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Issue: FOUN1-069 Respondent: ITS
Den: PH3P069 Extension: CBI: N
Commenter: ENVIRONMENTAL TECHNOLOGY COUNCIL
Comment Number: 00021
//COMM21
//RESPTTS
//SUB JFOUN1-069
THE ETC SUPPORTS EPA"S PROPOSAL TO CLASSIFY AS IMPERMISSIBLE DILUTION
THE USE OF IRON DUST OR FILINGS AS STABILIZING AGENTS FOR CERTAIN
CHARACTERISTIC WASTES. ETC AGREES FULLY WITH EPA"S DISCUSSION IN THE
PREAMBLE, 60 FR 11731, AND ADDS FURTHER THAT NO CHEMICAL REACTION OR
POZZOLANIC REACTION IS POSSIBLE FROM IRON DUST OR FILINGS. THEREFORE
MICROENCAPSULATION OR STABILIZATION IS NOT TAKING PLACE, ONLY DILUTION.
THERE IS NO CHEMISTRY THAT CAN BE CONTRIVED TO JUSTIFY THAT METALS
SUCH AS LEAD ARE BEING PERMANENTLY BOUND IN A NON-LEACHABLE MATRIX,
WHEN USING IRON DUST OR FILINGS AS A STABILIZING AGENT.
//ENDC21
RESPONSE
[The Agency thanks the commenter for their support.]
61
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Issue: FOUN1-086 Respondent: ITS
Den: PH3P086 Extension: CBI: N
Commenter: HERITAGE ENV SERVICES, INC
Comment Number: 00007
//COMM7
//RESPTTS
//SUBJFOUN1-086
REGULATING SPECIFIC PRACTICES BY RULE, RATHER THAN RIGOROUSLY
ENFORCING EXISTING ADEQUATE STATUTORY AND REGULATORY PROVISIONS,
WILL ADD REDUNDANT REGULATIONS THAT WILL ONLY SERVE TO COMPLICATE
THE LDR PROGRAM. EPA HAS PROPOSED TO PROHIBIT THE SPECIFIC PRACTICE OF
ADDING IRON AS A STABILIZATION REAGENT. EPA MADE A CONVINCING
ARGUMENT (60 FR 11731) THAT THIS PRACTICE CONSTITUTES IMPERMISSIBLE
DILUTION. IF THIS IS THE CASE, EPA, OR THE APPROPRIATE STATE REGULATORY
AGENCY, SHOULD TAKE ENFORCEMENT ACTION AGAINST FACILITIES EMPLOYING
THIS METHOD USING THE EXISTING DILUTION PROHIBITION AND THE TECHNICAL
ARGUMENT PRESENTED IN THE PROPOSED RULE. CURRENT REGULATORY
PROVISIONS AND THE TCLP TEST METHOD ARE SUFFICIENT TO DETERMINE
COMPLIANCE WITH LDR.
//ENDC7
RESPONSE
The Agency thanks the commenter for their support on this issue. The Agency is codifying
the determination that the addition of iron to a characteristically hazardous lead waste is
impermissible dilution (i.e. confirming that the practice already is prohibited under existing dilution
prohibition rules).
62
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Issue: FOUN1-100 Respondent: ITS
Dcn:PH3P100 Extension: CBI:N
Commenter: BEVERIDGE & DIAMOND, P.C.
Comment Number: 00001
//COMM1
//RESPTTS
//SUBJFOUN1-100
OUR CLIENT IS PARTICULARLY CONCERNED ABOUT ONE ASPECT OF EPA"S
PHASE III PROPOSED RULE, RELATING TO THE PROPOSED CODIFICATION OF THE
PRINCIPLES SET FORTH IN ITS MAY 23, 1994 "RCRA POLICY STATEMENT:
CLARIFICATION OF THE LAND DISPOSAL RESTRICTIONS" ["LDR"] DILUTION
PROHIBITION AND COMBUSTION OF INORGANIC METAL-BEARING HAZARDOUS
WASTES." IN THE COURSE OF ITS PREAMBLE DISCUSSION OF THE LDR DILUTION
PROHIBITION AS IT RELATES TO THE COMBUSTION OF INORGANIC METAL-BEARING
HAZARDOUS WASTES, EPA STATES THAT:
[T]HE AGENCY IS AWARE OF A PRACTICE WITHIN THE FOUNDRY INDUSTRY THAT
RECYCLES FOUNDRY SAND BY THERMALLY OXIDIZING IMPURITIES. IT IS EPA"S
VIEW THAT THIS PROCESS WOULD VIOLATE THE POLICY AGAINST COMBUSTION OF
INORGANICS, UNLESS THE FOUNDRY SAND BEING OXIDIZED CONTAINS TOXIC
ORGANIC CONSTITUENTS OR HAS A SIGNIFICANT ORGANIC COMPONENT.
60 FED. REG. AT 11,731.
EPA IN THE PREAMBLE DOES NOT ELABORATE ON THE BASIS FOR ITS IMPLICIT
DETERMINATION - REFLECTED IN THE FOREGOING STATEMENT - THAT RECYCLED
FOUNDRY SAND IS A SOLID AND HAZARDOUS WASTE SUBJECT TO RCRA SUBTITLE
C REGULATION, INCLUDING THE REQUIREMENTS OF THE LDR PROGRAM.
NEVERTHELESS, IT APPEARS THAT THE AGENCY"S INCLUSION OF THAT STATEMENT
IN THE PROPOSED PHASE III RULE IS AN OUTGROWTH OF ITS ONGOING
DISCUSSIONS WITH THE FOUNDRY INDUSTRY CONCERNING THE REGULATORY
STATUS OF RECYCLED FOUNDRY SAND, REUSED IN CASTING AND MOLDING
OPERATIONS. OUR CLIENT IS CONCERNED THAT, BY INTERJECTING ISSUES INTO
THE PHASE III SAND, EPA IS SHORT-CIRCUITING THOSE ONGOING DISCUSSIONS IN A
63
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MANNER THAT COULD UNDULY HINDER THE AGENCY"S AND INDUSTRY"S ISSUES
THAT HAVE BEEN RAISED TO DATA BY EPA CONCERNING FOUNDRY JUDGEMENTS
IN THE PHASE III RULE CONCERNING ISSUES RELATING TO THE THERMAL
RECONDITIONING OF FOUNDRY SAND, INCLUDING WHETHER SUCH PROCESSING
IMPLICATES THE "DILUTION PROHIBITION" AS IT RELATES TO THE "COMBUSTION"
OF INORGANIC METAL-BEARING "WASTES", EPA SHOULD ADDRESS SUCH ISSUES
COMPREHENSIVELY IN THE CONTEXT OF ITS ONGOING DISCUSSIONS WITH THE
FOUNDRY INDUSTRY CONCERNING RCRA ISSUES PERTAINING TO RECYCLED
FOUNDRY SAND.
//ENDC1
RESPONSE
(
The commenter requested clarification of its policy regarding the recycling of foundry sand
by thermal oxidation. The commenter points out that there have been ongoing discussions with the
Foundry industry with respect to the regulatory status of recycled foundry sand that is reused in
casting and molding operations.
The Agency acknowledges that there have been ongoing discussions between foundry
industry representatives and the Agency regarding the regulatory status of the practice of recycling
foundry sand by thermal oxidization of the impurities. However, the Agency notes that this issue is
outside the scope of this rulemaking. This rulemaking only addresses the issues related to the
addition of iron filings to spent foundry waste as a method of treatment.
64
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Issue: FOUN1-105 Respondent: ITS
Dcn:PH3P105 Extension: CBI:N
Commenter: NON-FERROUS FOUNDERS" SOCIETY
Comment Number: 00001
//COMM1
//RESPTTS
//SUBJFOUN1-105
THE FOUNDRY INDUSTRY AS-A WHOLE IS ONE OF THE NATION" S LEADING
RECYCLERS. THE BASIC FEEDSTOCK FOR MOST CASTINGS IS SCRAP METAL, WHICH
IN THE ABSENCE OF A VIABLE METALCASTING INDUSTRY, WOULD OTHERWISE BE
DESTINED FOR DISPOSAL IN LANDFILLS. IN ADDITION, THE OVERWHELMING
MAJORITY OF FOUNDRIES EMPLOY A SEND MOLDING PROCESS WHEREIN MOLTEN
METAL IS POURED INTO A SAND MOLD AND SOLIDIFIES INTO A DESIRED SHAPE.
THE SAND USED IN THIS PROCESS IS TYPICALLY RECYCLED AND REUSED BY THE
FOUNDRY UP TO AS MANY AS 100 TIMES. FEW OTHER INDUSTRIES CAN BOAST AS
HIGH AS RECYCLING RATE IN THEIR MANUFACTURING PROCESSES.
METALCASTING OPERATIONS ARE SUBJECT TO A HOST OF ENVIRONMENTAL AND
SAFETY AND HEALTH STANDARDS, REFLECTING TO SOME DEGREE THE EXTREME
CONDITIONS AND COMPLEX MATERIALS INHERENT IN THE INDUSTRY'S CORE
ACTIVITIES. THE FACT THAT SUCH STANDARDS ARE NEITHER UNIFORMLY
IMPOSED NOR AS STRINGENTLY ENFORCED ON FOUNDRIES IN OTHER COUNTRIES
AROUND THE WORLD PLACES U.S. FOUNDRIES AT A SEVERE COMPETITIVE
DISADVANTAGE IN INTERNATIONAL TRADE. THAT THE INDUSTRY PERSISTS AT ALL
IN SPITE OF THESE PRESSURES IS SIMPLY BECAUSE FOUNDRIES PROVIDE GOODS
WHICH HAVE NO ECONOMIC SUBSTITUTES.
DESPITE THE BURDEN THEY IMPOSE, FOUNDRIES MAKE CONCERTED EFFORTS TO
BE GOOD NEIGHBORS AND TO COMPLY WITH ALL ENVIRONMENTAL REGULATIONS.
HOWEVER, THE INDUSTRY IS CONCERNED THAT PROPOSED NEW REGULATIONS BE
BASED ON SOUND SCIENCE AND VALID COST/BENEFIT ANALYSES. REGRETTABLY,
THIS DOES NOT APPEAR TO BE THIS CASE WITH REGARD TO THE AGENCY"S
PROPOSED RULE "LAND DISPOSAL RESTRICTIONS - PHASE III: DECHARACTERIZED
WASTEWATERS, CARBAMATE AND ORGANOBROMINE WASTES AND SPENT
65
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POTLINERS" AS PUBLISHED IN THE MARCH 2, 1995 FEDERAL REGISTER (VOLUME 60,
NUMBER 41), PAGES 11702-11766.
THE NON-FERROUS FOUNDERS" SOCIETY FULLY SUPPORTS THE POSITIONS AND
ARGUMENTS PUT FORTH BY THE AMERICAN FOUNDRYMEN"S SOCIETY IN
RESPONSE TO THIS PROPOSED RULE, AS WELL AS THE SCIENTIFIC AND TECHNICAL
DISCUSSION OF THE CHEMICAL REACTIONS OF THE USE OF IRON FILINGS TO LEAD
BEARING WASTE A SUBMITTED BY RMT, INC. WE ARE CONFIDENT THAT A
THOROUGH REVIEW OF THE DOCKET WILL CLEARLY DEMONSTRATE THAT THE
AGENCY"S PROPOSAL TO DISALLOW THIS PRACTICE AS IMPERMISSIBLE DILUTION
UNDER 40 CFR 268.3 IS NEITHER SUPPORTED NOR JUSTIFIED. RATHER, RECORDS
CLEARLY SHOW THAT THE ADDITION OF SMALL ^AMOUNTS OF IRON FILINGS IS AN
EFFECTIVE TREATMENT FOR LEAD-BEARING WASTES, AND TCLP RESULTS
REGULARLY AND ROUTINELY SUPPORT THIS FACT.
(
WE ALSO BELIEVE THAT THE AGENCY"S COMMENTS ON THE INDUSTRY"S PRACTICE
OF RECYCLING FOUNDRY SAND BY THERMALLY OXIDIZING IMPURITIES ARE
SIMILARLY UNFOUNDED. MOREOVER, IT IS SOMEWHAT IRONIC THAT THE
DEVELOPMENT OF THIS TECHNOLOGY, WHICH EFFECTIVELY REDUCES WASTE BY
MORE THAN 80% WHILE RETURNING RAW MATERIALS TO THE CASTING PROCESS,
HAS BEEN BOTH LAUDED AND, IN FACT, PARTIALLY FUNDED BY OTHER
GOVERNMENT AGENCIES IN RECENT YEARS. ONCE AGAIN, NFFS DRAWS SPECIFIC
ATTENTION AND FULLY CONCURS WITH THE AFT COMMENT IN THIS REGARD.
THE NON-FERROUS FOUNDERS" SOCIETY REMAINS CONVINCED THAT THE AGENCY
CAN SHOW NO EVIDENCE OF ENVIRONMENTAL HARM CAUSED BY THE THERMAL
RECLAMATION OF FOUNDRY SAND, NOR CAN IT JUSTIFY THE DISALLOWANCE OF
THE PROVEN TREATMENT METHOD OF ADDING IRON FILINGS TO FOUNDRY WASTE
PRIOR TO THEIR DISPOSAL. WE ARE CONFIDENT THAT UPON PROPER
CONSIDERATION OF THE FACTS IN THE DOCKET, THE AGENCY WILL COME TO
REALIZE THAT NEITHER SOUND SCIENCE NOR VALID COST/BENEFIT ANALYSES
HAVE BEEN APPLIED IN THIS REGARD, AND THAT THIS PROPOSED RULE IS BOTH
UNNECESSARY AND UNJUSTIFIED.
//ENDC1
RESPONSE
The NFFS objected to EPA's position against addition of iron dust to foundry sand and
requested clarification of its policy regarding the recycling of foundry sand by thermal oxidation.
The main points raised by NFFS are:
1. supports the positions and arguments put forth by the American Foundrymen's Society (AFS)
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response, which objected to EPA's position against addition of iron dust to foundry sand;
2. A valid cost/benefit analysis has not been applied in this proposed rule.
The Agency's determination that the addition of iron filing constitutes impermissible dilution
is predicated on the fact that the adsorption of soluble lead on to the iron surface is a reversible
reaction and once the iron surfaces oxidize, the ability of the additive to scavenge soluble metals is
diminished. Therefore, the treatment is not permanent. In addition, adsorption alone is not a reliable
method of permanently immobilizing lead. The longevity of treatment cannot be measured by the
TCLP test, which provides only a snapshot of the leachable constituents under the test condition at
the time of analysis.
Studies conducted by Dr. Drexler, concluded that the addition of iron filings changes the
leaching fluids characteristics by increasing the pH and lowering Eh and DO to levels that are unlike
most natural environments. The study found that the increase in pH (lowering of hydrogen ion
activity) alone will lower the solubility of Pb in the test and insure a greater frequency of "passes."
The Agency infers from this that the immediate test conditions would not be representative of the
long-term landfill conditions. In the actual landfill, oxygen would defuse in to oxidize the metal
filings increasing Eh and DO, decreasing pH. This would act to remove the initial adsorption of lead
on the iron filings and results in leaching toxic levels of lead into the environment. This is evident
from the TCLP tests done on waste sand from the Nacogdoches landfill that showed lead
concentrations in the extracts ranging from 2.81 mg/1 to 11.6 mg/1. Therefore, the addition of filings
gives but a temporary effect unlike the long lasting effects obtained through microencapsulation or
other true treatment technologies which substantially reduce metal mobility.
The Agency continues to believe that this treatment should be classified as impermissible
dilution. The Agency has concluded that this form of stabilization is inadequate to minimize the
threats posed by land disposal of metal-containing hazardous wastes. EPA, therefore considers this
technology "impermissible dilution" in accordance with 40 CFR 268.3. Although the addition of
iron dust filings is considered treatment under 260. 1 0, the Agency does not believe it is adequate
treatment; but merely the addition of material as a substitute for adequate treatment and therefore
constitutes impermissible dilution. See 40 CFR 268.3 (b), 54 FR at 48494 (November 1989), and 55
FR at 22532 (June 1,1990).
The Agency is codifying this determination by amending 40 CFR 268.3 to read as follows:
40 CFR 268
§ 268.3 Dilution prohibited as a substitute for treatment
* * *
(d) It is a form of impermissible dilution, and therefore prohibited, to add iron filings or other
metallic forms of iron to lead-containing hazardous wastes in order to achieve any land disposal
restriction treatment standard for lead. Lead-containing wastes include D008 wastes (wastes
exhibiting a characteristic due to the presence of lead), all characteristic wastes containing lead as an
underlying hazardous constituent, listed wastes containing lead as a regulated constituent, and
67
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hazardous media containing any of the aforementioned lead-containing wastes.
* *
Regarding the comment on foundry industry's practice of reclaiming foundry sand by thermal
oxidization of impurities, the Agency notes that this issue is outside the scope of this rulemaking.
This rulemaking only addresses the issues related to the addition of iron filings to spent foundry
waste as a method of treatment.
With respect to the comment on cost/benefit analysis, the Agency disagrees that a valid
cost/benefit analysis was not performed. The reader is refered to the Regulatory Impact Analysis
(RIA) published as part of the proposed rule, which also includes a cost/benefit analysis.
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Issue: FOUN1-108 Respondent: TTS
Dcn:PH3P108 Extension: CBI:N
Commenter: GMD ENV SYSTEMS, INC
Comment Number: 00001
//COMM1
//RESPPGS
//SUBJFOUN1-108
IN THAT MARCH 2, 1995 PROPOSED, ON PAGE 11731, THE AGENCY MAKES THE
FOLLOWING STATEMENT.
"THE AGENCY IS AWARE OF A PRACTICE WITHIN THE FOUNDRY INDUSTRY
THAT RECYCLES FOUNDRY SAND BY THERMALLY OXIDIZING IMPURITIES. IT IS
EPA"S VIEW THAT THIS PROCESS WOULD VIOLATE THE POLICY AGAINST
COMBUSTION OF INORGANICS, UNLESS THE FOUNDRY SAND BEING OXIDIZED
CONTAINS TOXIC ORGANIC CONSTITUENTS OR HAS A SIGNIFICANT ORGANIC
COMPONENT (AS DESCRIBED ABOVE).
THE FIRST SENTENCE IS A CORRECT STATEMENT. THERE ARE FOUNDRIES WITHIN
THE FOUNDRY INDUSTRY WHO RECYCLE (REUSE) FOUNDRY SAND BY CALCINING A
PORTION OF THE RETURN SAND. HOWEVER, THE REMAINDER OF THAT STATEMENT
IS NOT CORRECT. RECYCLING RETURN SAND IN A FOUNDRY PROCESS IS NOT A
"TREATMENT" OF WASTE, THEREFORE, A FOUNDRY UTILIZING THIS RECYCLING
EQUIPMENT IS NOT IN VIOLATION OF THE POLICY AGAINST COMBUSTION OF
INORGANIC.
THE PROCESS OF CALCINING A RETURN SAND WITHIN THE FOUNDRY PROCESS
IS NOT TREATMENT OF A WASTE, I.E. RETURN SAND IS NOT A WASTE.
THE PROCESS REFERRED TO IS A PART OF THE FOUNDRY PROCESS. IT MERELY
DIRECTS A CERTAIN PORTION OF THE RETURN SAND TO THE RECYCLING
EQUIPMENT WHICH CALCINES THE FEED MATERIAL. AFTER THE SAND IS
PROCESSED THROUGH THE CALCINER, IT IS RETURNED TO THE FOUNDRY PROCESS
FOR REUSE IN IT"S ORIGINAL STATE.
69
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FURTHERMORE, THE RECYCLING PROCESS DOES NOT OXIDIZE THE
INORGANIC, IN THIS CASE SILICA, I.E. SILICON DIOXIDE (SIO2).
WE WISH TO DIRECT YOUR ATTENTION TO THE AGENCY" S DEFINITION OF THERMAL
TREATMENT
"THERMAL TREATMENT IS ANY METHOD, TECHNIQUE, OR PROCESS,
INCLUDING NEUTRALIZATION, DESIGNED TO CHANGE THE PHYSICAL, CHEMICAL,
OR BIOLOGICAL CHARACTER OF COMPOSITION OF THE WASTE".
ALSO PLEASE NOTE THE DEFINITION OF CALCINING,
"TO HEAT TO A TEMPERATURE BUT WITHOUT FUSING IN ORDER TO DRIVE OFF
VOLATILE MATTER".
(
IT SHOULD BE NOTED THAT THE CALCINING PROCESS DOES NOT CHANGE THE
CHEMICAL , PHYSICAL OR BIOLOGICAL CHARACTER OR COMPOSITION OF THE
SAND, I.E. SILICA, I.E. SILICON DIOXIDE (SIO2).
BASED ON THAT DEFINITION, THE FOUNDRY PROCESS OF USING EQUIPMENT
DESIGNED FOR THE EXPRESS PURPOSE OF RECOVERING AND REUSING A MATERIAL
PRODUCT, IN THIS CASE A NATURAL RESOURCE, DOES NOT CONSTITUTE
TREATMENT.
//ENDC1
RESPONSE
The commenter requested clarification of EPA's policy regarding the recycling of foundry
sand by thermal oxidation. The commenter asserts that thermal treatment of foundry sand is a
calcining operation and not incineration. The calcination process takes place at a lower temperature
than glassification. There is no melting of the solid materials but a volatilization of some waste
components. The Agency notes that this issue is outside the scope of this rulemaking. This
rulemaking only addresses the issues related to the addition of iron filings to spent foundry waste as
a method of treatment.
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Issue: FOUN1-123 Respondent: ITS
Den: PH3P123 Extension: CBI: N
Commenter: CHESAPEAK SPECIALTY PRODUCTS
Comment Number: 00001
//COMM1
//RESPTTS
//SUBJFOUN1-123
SSPC RECOMMENDATIONS
SSPC SUGGESTS THE FOLLOWING LANGUAGE FOR A RULE:
ALL WASTE GENERATED DURING BLAST CLEANING OF LEAD PAINTED STEEL
STRUCTURES SHALL BE DISPOSED OF A HAZARDOUS WASTE REGARDLESS OF THE
TYPE; STEEL, MINERAL, SLAG, ETC. ABRASIVE USED FOR BLAST CLEANING. WASTE
IS DEFINED AS SPENT ABRASIVE, PAINT CHIPS, RUST, MILL SCALE, DUST, AND
OTHER DEBRIS NOT INTENDED FOR RECYCLING.
//ENDC1
RESPONSE
The Agency recognizes that the waste residues resulting from blast cleaning could contain a
mixture of lead paint and metallic iron fines and therefore, could exhibit toxicity characteristic for
lead. However, the Agency notes that the use of iron abrasives for removing lead paint from steel is
part of the blast cleaning process and therefore, the presence of iron fines in the residues would not
result in impermissible dilution. The current rulemaking only addresses dilution prohibition as it
applies to processes that treat hazardous wastes and not for processes that generate a waste. The
Agency also notes that it is beyond the scope of this rulemaking to list all lead abatement waste as
hazardous.
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50272-101
REPORT DOCUMENTATION
PAGE
11. Report No.
12.
EPA530-R-99-020a
13. Recipient's Accession No.
I
| PB99-155822
4. Title and Subtitle | 5. Report Date
Response to Comments Document: Land Disposal Restrictions-Phase IV: Final Rule Promulgating Treatment | April 1998
Standards for Metal Wastes and Mineral Processing Wastes; Mineral Processing Secondary Materials and Bevill
Exclusion Issues; Treatment Standards for Hazardous Soils, and Exclusion of Recycled Wood Preserving Wastes;
Volume 1: Comments Related to Phase III Proposed Rule, March 2,1997
6.
7. Authors)
8. Performing Organization Rept. No.
9. Performing Organization Name and Address
U.S. EPA
OFFICE OF SOLID WASTE
401 M STREET, SW
WASHINGTON, DC 20460
10. Project/Task/Work Unit No.
11. Contract © or Grant (G) No.
(G)
12. Sponsoring Organization Name and Address
13. Type of Report & Period Covered
Response to Public Comment
14.
15. Supplementary Notes
16. Abstract (Limit: 200 words)
Responds to public comments relevant to foundry sand issues.
17. Document Analysis a. Descriptors
b. Identifiers/Open-Ended Terms
C.COSATI Field Group
18. Availability Statement
RELEASE UNLIMITED
119. Security Class (This Report) 121. No. of Pages
| UNCLASSIFIED | OQ
I I
| 20. Security Class (This Page) 122. Price
| UNCLASSIFIED
(SeeANSI-Z39.18)
OPTIONAL FORM 272 (4-77)
(Formerly NTIS-35)
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