<XBRL>
<?xml version="1.0" encoding="us-ascii" standalone="no"?>
<!--XBRL document created with Bowne Tagger XBRL Enabler by Bowne Software version 10.0.0.34-->
<!--Based on XBRL 2.1-->
<!--Created on: 5/2/2009 3:39:39 AM-->
<!--Modified on: 4/29/2010 6:15:08 AM-->
<linkbase xmlns="http://www.xbrl.org/2003/linkbase" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xlink="http://www.w3.org/1999/xlink" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <roleRef xlink:type="simple" xlink:href="wm-20100331.xsd#LandfillAndEnvironmentalRemediationLiabilities" roleURI="http://wm.com/role/LandfillAndEnvironmentalRemediationLiabilities" />
  <roleRef xlink:type="simple" xlink:href="wm-20100331.xsd#IncomeTaxes" roleURI="http://wm.com/role/IncomeTaxes" />
  <roleRef xlink:type="simple" xlink:href="wm-20100331.xsd#CommitmentsAndContingencies" roleURI="http://wm.com/role/CommitmentsAndContingencies" />
  <roleRef xlink:type="simple" xlink:href="wm-20100331.xsd#Restructuring" roleURI="http://wm.com/role/Restructuring" />
  <roleRef xlink:type="simple" xlink:href="wm-20100331.xsd#SegmentAndRelatedInformation" roleURI="http://wm.com/role/SegmentAndRelatedInformation" />
  <roleRef xlink:type="simple" xlink:href="wm-20100331.xsd#IncomeExpenseFromDivestituresAssetImpairmentsAndUnusualItems" roleURI="http://wm.com/role/IncomeExpenseFromDivestituresAssetImpairmentsAndUnusualItems" />
  <roleRef xlink:type="simple" xlink:href="wm-20100331.xsd#FairValueMeasurements" roleURI="http://wm.com/role/FairValueMeasurements" />
  <roleRef xlink:type="simple" xlink:href="wm-20100331.xsd#CondensedConsolidatingFinancialStatements" roleURI="http://wm.com/role/CondensedConsolidatingFinancialStatements" />
  <roleRef xlink:type="simple" xlink:href="wm-20100331.xsd#BalanceSheets" roleURI="http://wm.com/role/BalanceSheets" />
  <roleRef xlink:type="simple" xlink:href="wm-20100331.xsd#StatementsOfOperations" roleURI="http://wm.com/role/StatementsOfOperations" />
  <roleRef xlink:type="simple" xlink:href="wm-20100331.xsd#StatementsOfCashFlows" roleURI="http://wm.com/role/StatementsOfCashFlows" />
  <roleRef xlink:type="simple" xlink:href="wm-20100331.xsd#BalanceSheetsParenthetical" roleURI="http://wm.com/role/BalanceSheetsParenthetical" />
  <roleRef xlink:type="simple" xlink:href="wm-20100331.xsd#StatementsOfChangesInEquity" roleURI="http://wm.com/role/StatementsOfChangesInEquity" />
  <roleRef xlink:type="simple" xlink:href="wm-20100331.xsd#StatementsOfChangesInEquityParenthetical" roleURI="http://wm.com/role/StatementsOfChangesInEquityParenthetical" />
  <roleRef xlink:type="simple" xlink:href="wm-20100331.xsd#Debt" roleURI="http://wm.com/role/Debt" />
  <roleRef xlink:type="simple" xlink:href="wm-20100331.xsd#NewAccountingStandardsPendingAdoption" roleURI="http://wm.com/role/NewAccountingStandardsPendingAdoption" />
  <roleRef xlink:type="simple" xlink:href="wm-20100331.xsd#EarningPerShare" roleURI="http://wm.com/role/EarningPerShare" />
  <roleRef xlink:type="simple" xlink:href="wm-20100331.xsd#ComprehensiveIncome" roleURI="http://wm.com/role/ComprehensiveIncome" />
  <roleRef xlink:type="simple" xlink:href="wm-20100331.xsd#BasisOfPresentation" roleURI="http://wm.com/role/BasisOfPresentation" />
  <roleRef xlink:type="simple" xlink:href="wm-20100331.xsd#DerivativeInstrumentsAndHedgingActivities" roleURI="http://wm.com/role/DerivativeInstrumentsAndHedgingActivities" />
  <roleRef xlink:type="simple" xlink:href="wm-20100331.xsd#DocumentAndEntityInformation" roleURI="http://wm.com/role/DocumentAndEntityInformation" />
  <calculationLink xlink:type="extended" xlink:role="http://wm.com/role/LandfillAndEnvironmentalRemediationLiabilities" xlink:title="0202 - Disclosure - Landfill and Environmental Remediation Liabilities" />
  <calculationLink xlink:type="extended" xlink:role="http://wm.com/role/IncomeTaxes" xlink:title="0205 - Disclosure - Income Taxes" />
  <calculationLink xlink:type="extended" xlink:role="http://wm.com/role/CommitmentsAndContingencies" xlink:title="0208 - Disclosure - Commitments and Contingencies" />
  <calculationLink xlink:type="extended" xlink:role="http://wm.com/role/Restructuring" xlink:title="0209 - Disclosure - Restructuring" />
  <calculationLink xlink:type="extended" xlink:role="http://wm.com/role/SegmentAndRelatedInformation" xlink:title="0210 - Disclosure - Segment and Related Information" />
  <calculationLink xlink:type="extended" xlink:role="http://wm.com/role/IncomeExpenseFromDivestituresAssetImpairmentsAndUnusualItems" xlink:title="0211 - Disclosure - (Income) Expense from Divestitures, Asset Impairments and Unusual Items" />
  <calculationLink xlink:type="extended" xlink:role="http://wm.com/role/FairValueMeasurements" xlink:title="0212 - Disclosure - Fair Value Measurements" />
  <calculationLink xlink:type="extended" xlink:role="http://wm.com/role/CondensedConsolidatingFinancialStatements" xlink:title="0213 - Disclosure - Condensed Consolidating Financial Statements" />
  <calculationLink xlink:type="extended" xlink:role="http://wm.com/role/BalanceSheets" xlink:title="0110 - Statement - Condensed Consolidated Balance Sheets">
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="loc_LiabilitiesAndStockholdersEquity" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_Liabilities" xlink:label="loc_Liabilities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_LiabilitiesAndStockholdersEquity" xlink:to="loc_Liabilities" order="40" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_DeferredTaxLiabilitiesNoncurrent" xlink:label="loc_DeferredTaxLiabilitiesNoncurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_Liabilities" xlink:to="loc_DeferredTaxLiabilitiesNoncurrent" order="40" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="loc_LiabilitiesCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_Liabilities" xlink:to="loc_LiabilitiesCurrent" order="20" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_Assets" xlink:label="loc_Assets" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="loc_OtherAssetsNoncurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_Assets" xlink:to="loc_OtherAssetsNoncurrent" order="100" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="loc_IntangibleAssetsNetExcludingGoodwill" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_Assets" xlink:to="loc_IntangibleAssetsNetExcludingGoodwill" order="80" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_Goodwill" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_Assets" xlink:to="loc_Goodwill" order="60" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_PropertyPlantAndEquipmentNet" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_Assets" xlink:to="loc_PropertyPlantAndEquipmentNet" order="40" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="loc_AssetsCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_Assets" xlink:to="loc_AssetsCurrent" order="20" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_OtherAssetsCurrent" xlink:label="loc_OtherAssetsCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_AssetsCurrent" xlink:to="loc_OtherAssetsCurrent" order="120" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_DeferredTaxAssetsNetCurrent" xlink:label="loc_DeferredTaxAssetsNetCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_AssetsCurrent" xlink:to="loc_DeferredTaxAssetsNetCurrent" order="100" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_Supplies" xlink:label="loc_Supplies" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_AssetsCurrent" xlink:to="loc_Supplies" order="80" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="loc_AccountsReceivableNetCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_AssetsCurrent" xlink:to="loc_AccountsReceivableNetCurrent" order="60" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="loc_CashAndCashEquivalentsAtCarryingValue" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_AssetsCurrent" xlink:to="loc_CashAndCashEquivalentsAtCarryingValue" order="40" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_OtherReceivables" xlink:label="loc_OtherReceivables" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_AssetsCurrent" xlink:to="loc_OtherReceivables" order="20" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:label="loc_OtherLiabilitiesNoncurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_Liabilities" xlink:to="loc_OtherLiabilitiesNoncurrent" order="60" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:label="loc_AccountsPayableCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_LiabilitiesCurrent" xlink:to="loc_AccountsPayableCurrent" order="40" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="loc_AccruedLiabilitiesCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_LiabilitiesCurrent" xlink:to="loc_AccruedLiabilitiesCurrent" order="20" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="loc_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_LiabilitiesAndStockholdersEquity" xlink:to="loc_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_StockholdersEquity" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:to="loc_StockholdersEquity" order="40" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_AccumulatedOtherComprehensiveIncomeLossNetOfTax" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_StockholdersEquity" xlink:to="loc_AccumulatedOtherComprehensiveIncomeLossNetOfTax" order="80" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="loc_RetainedEarningsAccumulatedDeficit" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_StockholdersEquity" xlink:to="loc_RetainedEarningsAccumulatedDeficit" order="60" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_AdditionalPaidInCapitalCommonStock" xlink:label="loc_AdditionalPaidInCapitalCommonStock" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_StockholdersEquity" xlink:to="loc_AdditionalPaidInCapitalCommonStock" order="40" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_CommonStockValue" xlink:label="loc_CommonStockValue" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_StockholdersEquity" xlink:to="loc_CommonStockValue" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_MinorityInterest" xlink:label="loc_MinorityInterest" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:to="loc_MinorityInterest" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_DeferredRevenueAndCreditsCurrent" xlink:label="loc_DeferredRevenueAndCreditsCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_LiabilitiesCurrent" xlink:to="loc_DeferredRevenueAndCreditsCurrent" order="80" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_DebtCurrent" xlink:label="loc_DebtCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_LiabilitiesCurrent" xlink:to="loc_DebtCurrent" order="60" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligations" xlink:label="loc_LongTermDebtAndCapitalLeaseObligations" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_Liabilities" xlink:to="loc_LongTermDebtAndCapitalLeaseObligations" order="100" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="wm-20100331.xsd#wmi_AccruedCappingClosureAndPostClosureCostsAndEnvironmentalLossContingencies" xlink:label="wmi_AccruedCappingClosureAndPostClosureCostsAndEnvironmentalLossContingencies" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_Liabilities" xlink:to="wmi_AccruedCappingClosureAndPostClosureCostsAndEnvironmentalLossContingencies" order="80" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_TreasuryStockValue" xlink:label="loc_TreasuryStockValue" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_StockholdersEquity" xlink:to="loc_TreasuryStockValue" order="100" use="optional" weight="-1" priority="1" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://wm.com/role/StatementsOfOperations" xlink:title="0120 - Statement - Condensed Consolidated Statements of Operations (Unaudited)">
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_NetIncomeLoss" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" xlink:label="loc_NetIncomeLossAttributableToNoncontrollingInterest" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetIncomeLoss" xlink:to="loc_NetIncomeLossAttributableToNoncontrollingInterest" order="40" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_ProfitLoss" xlink:label="loc_ProfitLoss" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetIncomeLoss" xlink:to="loc_ProfitLoss" order="20" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_IncomeTaxExpenseBenefit" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_ProfitLoss" xlink:to="loc_IncomeTaxExpenseBenefit" order="40" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="wm-20100331.xsd#wmi_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsCumulativeEffectsOfChangesInAccountingPrinciplesAndNoncontlingInterest" xlink:label="wmi_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsCumulativeEffectsOfChangesInAccountingPrinciplesAndNoncontlingInterest" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_ProfitLoss" xlink:to="wmi_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsCumulativeEffectsOfChangesInAccountingPrinciplesAndNoncontlingInterest" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="wm-20100331.xsd#wmi_InterestAndOtherIncomeExpenseTotal" xlink:label="wmi_InterestAndOtherIncomeExpenseTotal" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="wmi_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsCumulativeEffectsOfChangesInAccountingPrinciplesAndNoncontlingInterest" xlink:to="wmi_InterestAndOtherIncomeExpenseTotal" order="40" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="loc_OtherNonoperatingIncomeExpense" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="wmi_InterestAndOtherIncomeExpenseTotal" xlink:to="loc_OtherNonoperatingIncomeExpense" order="80" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="wm-20100331.xsd#wmi_InterestIncome" xlink:label="wmi_InterestIncome" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="wmi_InterestAndOtherIncomeExpenseTotal" xlink:to="wmi_InterestIncome" order="60" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="loc_OperatingIncomeLoss" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="wmi_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsCumulativeEffectsOfChangesInAccountingPrinciplesAndNoncontlingInterest" xlink:to="loc_OperatingIncomeLoss" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_CostsAndExpenses" xlink:label="loc_CostsAndExpenses" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_OperatingIncomeLoss" xlink:to="loc_CostsAndExpenses" order="40" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="wm-20100331.xsd#wmi_IncomeExpenseFromDivestituresAssetImpairmentsAndUnusualItems" xlink:label="wmi_IncomeExpenseFromDivestituresAssetImpairmentsAndUnusualItems_2" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_CostsAndExpenses" xlink:to="wmi_IncomeExpenseFromDivestituresAssetImpairmentsAndUnusualItems_2" order="100" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_RestructuringCharges" xlink:label="loc_RestructuringCharges" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_CostsAndExpenses" xlink:to="loc_RestructuringCharges" order="80" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="wm-20100331.xsd#wmi_DepreciationDepletionAndAmortizationAssociatedWithPropertyPlantAndEquipmentAndIntangibleAssets" xlink:label="wmi_DepreciationDepletionAndAmortizationAssociatedWithPropertyPlantAndEquipmentAndIntangibleAssets" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_CostsAndExpenses" xlink:to="wmi_DepreciationDepletionAndAmortizationAssociatedWithPropertyPlantAndEquipmentAndIntangibleAssets" order="60" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpense" xlink:label="loc_SellingGeneralAndAdministrativeExpense" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_CostsAndExpenses" xlink:to="loc_SellingGeneralAndAdministrativeExpense" order="40" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_InterestAndDebtExpense" xlink:label="loc_InterestAndDebtExpense" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="wmi_InterestAndOtherIncomeExpenseTotal" xlink:to="loc_InterestAndDebtExpense" order="40" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_Revenues" xlink:label="loc_Revenues" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_OperatingIncomeLoss" xlink:to="loc_Revenues" order="20" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="wm-20100331.xsd#wmi_Operating" xlink:label="wmi_Operating" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_CostsAndExpenses" xlink:to="wmi_Operating" order="20" use="optional" weight="1" priority="1" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://wm.com/role/StatementsOfCashFlows" xlink:title="0130 - Statement - Condensed Consolidated Statements of Cash Flows (Unaudited)">
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:label="loc_CashAndCashEquivalentsPeriodIncreaseDecrease" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents" xlink:label="loc_EffectOfExchangeRateOnCashAndCashEquivalents" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:to="loc_EffectOfExchangeRateOnCashAndCashEquivalents" order="80" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="loc_NetCashProvidedByUsedInFinancingActivities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:to="loc_NetCashProvidedByUsedInFinancingActivities" order="60" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:label="loc_ProceedsFromPaymentsForOtherFinancingActivities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInFinancingActivities" xlink:to="loc_ProceedsFromPaymentsForOtherFinancingActivities" order="160" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities" xlink:label="loc_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInFinancingActivities" xlink:to="loc_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities" order="140" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:label="loc_PaymentsForRepurchaseOfCommonStock" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInFinancingActivities" xlink:to="loc_PaymentsForRepurchaseOfCommonStock" order="120" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="loc_NetCashProvidedByUsedInInvestingActivities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:to="loc_NetCashProvidedByUsedInInvestingActivities" order="40" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_PaymentsForProceedsFromOtherInvestingActivities" xlink:label="loc_PaymentsForProceedsFromOtherInvestingActivities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInInvestingActivities" xlink:to="loc_PaymentsForProceedsFromOtherInvestingActivities" order="140" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_IncreaseDecreaseInRestrictedCash" xlink:label="loc_IncreaseDecreaseInRestrictedCash" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInInvestingActivities" xlink:to="loc_IncreaseDecreaseInRestrictedCash" order="120" use="optional" weight="-1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="loc_NetCashProvidedByUsedInOperatingActivities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:to="loc_NetCashProvidedByUsedInOperatingActivities" order="20" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:label="loc_ShareBasedCompensation" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInOperatingActivities" xlink:to="loc_ShareBasedCompensation" order="220" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_ProvisionForDoubtfulAccounts" xlink:label="loc_ProvisionForDoubtfulAccounts" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInOperatingActivities" xlink:to="loc_ProvisionForDoubtfulAccounts" order="200" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:label="loc_DeferredIncomeTaxExpenseBenefit" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInOperatingActivities" xlink:to="loc_DeferredIncomeTaxExpenseBenefit" order="180" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:label="loc_PaymentsToAcquireBusinessesNetOfCashAcquired" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInInvestingActivities" xlink:to="loc_PaymentsToAcquireBusinessesNetOfCashAcquired" order="100" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="wm-20100331.xsd#wmi_InterestAccretionOnLandfillLiabilities" xlink:label="wmi_InterestAccretionOnLandfillLiabilities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInOperatingActivities" xlink:to="wmi_InterestAccretionOnLandfillLiabilities" order="160" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" xlink:label="loc_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInOperatingActivities" xlink:to="loc_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" order="140" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_ProceedsFromIssuanceOfLongTermDebtAndCapitalSecuritiesNet" xlink:label="loc_ProceedsFromIssuanceOfLongTermDebtAndCapitalSecuritiesNet" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInFinancingActivities" xlink:to="loc_ProceedsFromIssuanceOfLongTermDebtAndCapitalSecuritiesNet" order="100" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_RepaymentsOfLongTermDebtAndCapitalSecurities" xlink:label="loc_RepaymentsOfLongTermDebtAndCapitalSecurities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInFinancingActivities" xlink:to="loc_RepaymentsOfLongTermDebtAndCapitalSecurities" order="80" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_PaymentsOfDividendsCommonStock" xlink:label="loc_PaymentsOfDividendsCommonStock" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInFinancingActivities" xlink:to="loc_PaymentsOfDividendsCommonStock" order="60" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_ProfitLoss" xlink:label="loc_ProfitLoss" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInOperatingActivities" xlink:to="loc_ProfitLoss" order="120" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="wm-20100331.xsd#wmi_InterestAccretionOnAndDiscountRateAdjustmentsToEnvironmentalRemediationLiabilitiesAndRecoveryAssets" xlink:label="wmi_InterestAccretionOnAndDiscountRateAdjustmentsToEnvironmentalRemediationLiabilitiesAndRecoveryAssets" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInOperatingActivities" xlink:to="wmi_InterestAccretionOnAndDiscountRateAdjustmentsToEnvironmentalRemediationLiabilitiesAndRecoveryAssets" order="300" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_ExcessTaxBenefitFromShareBasedCompensationOperatingActivities" xlink:label="loc_ExcessTaxBenefitFromShareBasedCompensationOperatingActivities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInOperatingActivities" xlink:to="loc_ExcessTaxBenefitFromShareBasedCompensationOperatingActivities" order="260" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsAndOtherReceivables" xlink:label="loc_IncreaseDecreaseInAccountsAndOtherReceivables" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInOperatingActivities" xlink:to="loc_IncreaseDecreaseInAccountsAndOtherReceivables" order="280" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="wm-20100331.xsd#wmi_IncreaseDecreaseInOtherAssetsCurrent" xlink:label="wmi_IncreaseDecreaseInOtherAssetsCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInOperatingActivities" xlink:to="wmi_IncreaseDecreaseInOtherAssetsCurrent" order="100" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="wm-20100331.xsd#wmi_IncreaseDecreaseInOtherAssetsNonCurrent" xlink:label="wmi_IncreaseDecreaseInOtherAssetsNonCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInOperatingActivities" xlink:to="wmi_IncreaseDecreaseInOtherAssetsNonCurrent" order="80" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" xlink:label="loc_IncreaseDecreaseInOtherOperatingLiabilities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInOperatingActivities" xlink:to="loc_IncreaseDecreaseInOtherOperatingLiabilities" order="60" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="wm-20100331.xsd#wmi_ProceedsFromDivestituresOfBusinessesAndOtherSalesOfAssets" xlink:label="wmi_ProceedsFromDivestituresOfBusinessesAndOtherSalesOfAssets" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInInvestingActivities" xlink:to="wmi_ProceedsFromDivestituresOfBusinessesAndOtherSalesOfAssets" order="40" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_ProceedsFromPaymentsToMinorityShareholders" xlink:label="loc_ProceedsFromPaymentsToMinorityShareholders" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInFinancingActivities" xlink:to="loc_ProceedsFromPaymentsToMinorityShareholders" order="40" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_PaymentsToAcquireProductiveAssets" xlink:label="loc_PaymentsToAcquireProductiveAssets" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInInvestingActivities" xlink:to="loc_PaymentsToAcquireProductiveAssets" order="20" use="optional" weight="-1" priority="1" />
    <loc xlink:type="locator" xlink:href="wm-20100331.xsd#wmi_DepreciationDepletionAndAmortizationAssociatedWithPropertyPlantAndEquipmentAndIntangibleAssets" xlink:label="wmi_DepreciationDepletionAndAmortizationAssociatedWithPropertyPlantAndEquipmentAndIntangibleAssets" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInOperatingActivities" xlink:to="wmi_DepreciationDepletionAndAmortizationAssociatedWithPropertyPlantAndEquipmentAndIntangibleAssets" order="40" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="wm-20100331.xsd#wmi_IncomeExpenseFromDivestituresAssetImpairmentsAndUnusualItems" xlink:label="wmi_IncomeExpenseFromDivestituresAssetImpairmentsAndUnusualItems_2" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInOperatingActivities" xlink:to="wmi_IncomeExpenseFromDivestituresAssetImpairmentsAndUnusualItems_2" order="20" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="loc_ProceedsFromStockOptionsExercised" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInFinancingActivities" xlink:to="loc_ProceedsFromStockOptionsExercised" order="20" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_GainLossOnSaleOfPropertyPlantEquipment" xlink:label="loc_GainLossOnSaleOfPropertyPlantEquipment" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInOperatingActivities" xlink:to="loc_GainLossOnSaleOfPropertyPlantEquipment" order="10" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_PaymentsToAcquireEquityMethodInvestments" xlink:label="loc_PaymentsToAcquireEquityMethodInvestments" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_NetCashProvidedByUsedInInvestingActivities" xlink:to="loc_PaymentsToAcquireEquityMethodInvestments" order="130" use="optional" weight="-1" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://wm.com/role/BalanceSheetsParenthetical" xlink:title="0111 - Statement - Condensed Consolidated Balance Sheets (Parenthetical)" />
  <calculationLink xlink:type="extended" xlink:role="http://wm.com/role/StatementsOfChangesInEquity" xlink:title="0140 - Statement - Condensed Consolidated Statements of Changes in Equity (Unaudited)">
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" xlink:label="loc_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecrease" xlink:label="loc_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecrease" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" xlink:to="loc_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecrease" order="40" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_OtherComprehensiveIncomeReclassificationAdjustmentOnDerivativesIncludedInNetIncomeNetOfTax" xlink:label="loc_OtherComprehensiveIncomeReclassificationAdjustmentOnDerivativesIncludedInNetIncomeNetOfTax" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecrease" xlink:to="loc_OtherComprehensiveIncomeReclassificationAdjustmentOnDerivativesIncludedInNetIncomeNetOfTax" order="100" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" xlink:label="loc_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecrease" xlink:to="loc_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" order="80" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_ProfitLoss" xlink:label="loc_ProfitLoss" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" xlink:to="loc_ProfitLoss" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_DividendsCommonStockCash" xlink:label="loc_DividendsCommonStockCash" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_OtherComprehensiveIncomeAvailableForSaleSecuritiesAdjustmentNetOfTaxPeriodIncreaseDecrease" xlink:label="loc_OtherComprehensiveIncomeAvailableForSaleSecuritiesAdjustmentNetOfTaxPeriodIncreaseDecrease" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecrease" xlink:to="loc_OtherComprehensiveIncomeAvailableForSaleSecuritiesAdjustmentNetOfTaxPeriodIncreaseDecrease" order="60" use="optional" weight="1" />
    <loc xlink:type="locator" xlink:href="wm-20100331.xsd#wmi_EquityBasedCompensationTransactionsIncludingDividendEquivalentsNetOfTaxes" xlink:label="wmi_EquityBasedCompensationTransactionsIncludingDividendEquivalentsNetOfTaxes" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod" xlink:label="loc_TreasuryStockValueAcquiredCostMethod" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders" xlink:label="loc_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders" />
    <loc xlink:type="locator" xlink:href="http://taxonomies.xbrl.us/us-gaap/2009/elts/us-gaap-2009-01-31.xsd#us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPeriodIncreaseDecrease" xlink:label="loc_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPeriodIncreaseDecrease" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecrease" xlink:to="loc_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPeriodIncreaseDecrease" order="20" use="optional" weight="1" priority="1" />
    <loc xlink:type="locator" xlink:href="wm-20100331.xsd#wmi_NoncontrollingInterestsInAcquiredBusinesses" xlink:label="wmi_NoncontrollingInterestsInAcquiredBusinesses" />
    <loc xlink:type="locator" xlink:href="wm-20100331.xsd#wmi_DeconsolidationOfVariableInterestsEntities" xlink:label="wmi_DeconsolidationOfVariableInterestsEntities" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://wm.com/role/StatementsOfChangesInEquityParenthetical" xlink:title="0141 - Statement - Condensed Consolidated Statements of Changes in Equity (Unaudited) (Parenthetical)" />
  <calculationLink xlink:type="extended" xlink:role="http://wm.com/role/Debt" xlink:title="0203 - Disclosure - Debt" />
  <calculationLink xlink:type="extended" xlink:role="http://wm.com/role/NewAccountingStandardsPendingAdoption" xlink:title="0214 - Disclosure - New Accounting Standards Pending Adoption" />
  <calculationLink xlink:type="extended" xlink:role="http://wm.com/role/EarningPerShare" xlink:title="0207 - Disclosure - Earnings Per Share" />
  <calculationLink xlink:type="extended" xlink:role="http://wm.com/role/ComprehensiveIncome" xlink:title="0206 - Disclosure - Comprehensive Income" />
  <calculationLink xlink:type="extended" xlink:role="http://wm.com/role/BasisOfPresentation" xlink:title="0201 - Disclosure - Basis of Presentation" />
  <calculationLink xlink:type="extended" xlink:role="http://wm.com/role/DerivativeInstrumentsAndHedgingActivities" xlink:title="0204 - Disclosure - Derivative Instruments and Hedging Activities" />
  <calculationLink xlink:type="extended" xlink:role="http://wm.com/role/DocumentAndEntityInformation" xlink:title="00 - Document - Document and Entity Information" />
</linkbase>
</XBRL>
