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October 3, 2006October 3, 2006 11
Arsenic and Landfills: Protecting Water Quality
Session VI. Old Landfills and Waste Sites
Rudi Hon Boston College,
Chestnut Hill, MA
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Session VI. Old Landfills and Waste SitesGeneral Questions
What do we know?
What do we not know?
Who knows – and needs to know – what?
Where do we go from here?
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Session VI. Old Landfills and Waste SitesSpecific and synthesis questions
1. How prevalent is arsenic contamination in the groundwaterdown-gradient of old, unlined landfills?
2. How arsenic contaminations at waste sites compare toarsenic contaminations down-gradient of old landfills? Dothey share any field and/or chemical characteristics?
3. Is there any evidence that might suggest that some arseniccontamination at old landfills may originate from within thelandfills?
4. What is the arsenic content of iron floc deposits commonlyobserved down-gradient of unlined landfills and what risksdo iron flocs pose?
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Session VI. Old Landfills and Waste SitesSpecific and synthesis questions (cont’d)
5. By comparing analytical data from sampling of leachatecollection systems to data from leachate-impacted groundwater what can we deduce about relative impacts oflandfilled arsenic wastes vs naturally occurring arsenicmobilized by leachate?
6. What experience do we have with respect to arsenic as a contaminant of concern at C&D debris landfills or in C&Ddebris that is proposed for beneficial uses?
7. Laboratory forward experiments/tests vs inverse problemsolutions of data from old landfills.
Chemical Composition of Human Body70-kg person
55
Element MassOxygen 43 kgCarbon 16 kgHydrogen 7 kgNitrogen 1.8 kgCalcium 1.0 kgPhosphorus 780 gPotassium 140 gSulfur 140 gSodium 100 gChlorine 95 gMagnesium 19 gIron 4.2 gFluorine 2.6 gZinc 2.3 gSilicon 1.0 g
Element MassRubidium 0.68 gStrontium 0.32 gBromine 0.26 gLead 0.12 gCopper 72 mgAluminum 60 mgCadmium 50 mgCerium 40 mgBarium 22 mgIodine 20 mgTin 20 mgTitanium 20 mgBoron 18 mgNickel 15 mgSelenium 15 mg
Chemical Composition of Human Body
6
70-kg personElement MassChromium 14 mgManganese 12 mgArsenic 7 mgLithium 7 mgCesium 6 mgMercury 6 mgGermanium 5 mgMolybdenum 5 mgCobalt 3 mgAntimony 2 mgSilver 2 mgNiobium 1.5 mgZirconium 1 mgLanthanium 0.8 mgGallium 0.7 mg
Element Mass Tellurium 0.7 mg Yttrium 0.6 mg Bismuth 0.5 mg Thallium 0.5 mg Indium 0.4 mg Gold 0.2 mg Scandium 0.2 mg Tantalum 0.2 mg Vanadium 0.11 mg Thorium 0.1 mg Uranium 0.1 mg Samarium 50 µg Beryllium 36 µgTungsten 20 µg
6
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Spot Analysis - Grain 12/1
* ***
* 20
16
1718
19
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Background diagram:cobaltite - white circlesgersdorrfite - trianglesarsenopyrite - white blocks
Cobaltite Background diagram reference:Melekestseva, Zaykov, Belogub, and Tesalina, (2004): Sulpharsenides and Arsenides in Massive Sulphide Deposits Connected with Ultramafites, South Urals; Applied Mineralogy, Pecchio et al. (eds) 2004 ICAM-BR, São Paulo.
Cobaltite - GersdorrfiteSolid Solution Range – Bedrock,Central Massacusetts
Gersd
orrfi
te
Arsenopyrite
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Nickel vs Arsenic in Soils -- Devens
Soil Background -- Devens
y = 1.0215xR2 = 0.666
01020304050607080
0 20 40 60 80As ppm
Ni p
pm
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Central Mass Bottom SedimentsNickel in Grove Pond Bottom Sediments
y = 0.6965x - 7.9309R2 = 0.8074
0102030405060708090
100
0 20 40 60 80 100 120 140 160As ppm
Ni p
pm
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Figure 13: Map showing the extent of the Merrimack Belt, position of the Clinton-Newbury Fault System, and the location of the towns where elevated arsenic in groundwater has been observed near landfills.
