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  <xs:element id="shc_DepreciationExpenseAssetRetirementObligation" abstract="false" name="DepreciationExpenseAssetRetirementObligation" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="shc_DecommissioningObligationLettersOfCreditAndSuretyBondsOutstanding" abstract="false" name="DecommissioningObligationLettersOfCreditAndSuretyBondsOutstanding" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="shc_TriggeringEventAxis" abstract="true" name="TriggeringEventAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="shc_TriggeringEventDomain" abstract="true" name="TriggeringEventDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="shc_SelectedAsTheFirstPlaintiffGroupMember" abstract="true" name="SelectedAsTheFirstPlaintiffGroupMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="shc_ConsolidatedForPretrialPurposesMember" abstract="true" name="ConsolidatedForPretrialPurposesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="shc_ExcludeCertainExpertWitnessesMember" abstract="true" name="ExcludeCertainExpertWitnessesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="shc_OtherClaimsMember" abstract="true" name="OtherClaimsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="shc_PersonalInjuryAndWrongfulDeathMember" abstract="true" name="PersonalInjuryAndWrongfulDeathMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="shc_PersonalInjuryMember" abstract="true" name="PersonalInjuryMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="shc_PropertyDevaluationMember" abstract="true" name="PropertyDevaluationMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="shc_AssetTransferCaseMember" abstract="true" name="AssetTransferCaseMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="shc_WillowbrookCasesMember" abstract="true" name="WillowbrookCasesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="shc_NumberOfCasesThatWillProceedToJudicialDetermination" abstract="false" name="NumberOfCasesThatWillProceedToJudicialDetermination" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="shc_NumberOfCasesIncludingPersonalInjuryAndPropertyClaims" abstract="false" name="NumberOfCasesIncludingPersonalInjuryAndPropertyClaims" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="shc_LossContingencyUndiscountedAmountOfInsuranceRelatedAssessmentLiabilityPerOccurrence" abstract="false" name="LossContingencyUndiscountedAmountOfInsuranceRelatedAssessmentLiabilityPerOccurrence" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="shc_GrossSettlementAndDefenseCostsIncurred" abstract="false" name="GrossSettlementAndDefenseCostsIncurred" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="shc_FinanceLeaseLiabilityMember" abstract="true" name="FinanceLeaseLiabilityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="shc_LongTermDebtCurrentMaturitiesFairValue" abstract="false" name="LongTermDebtCurrentMaturitiesFairValue" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="shc_CustomerOneMember" abstract="true" name="CustomerOneMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="shc_CustomerTwoMember" abstract="true" name="CustomerTwoMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="shc_DepreciationAmortizationAndAdditions" abstract="false" name="DepreciationAmortizationAndAdditions" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="shc_ForeignCurrencyGainLossAndGainLossOnEmbeddedDerivative" abstract="false" name="ForeignCurrencyGainLossAndGainLossOnEmbeddedDerivative" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="shc_OtherGeographicalAreasMember" abstract="true" name="OtherGeographicalAreasMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="shc_PercentOfRevenueFromContractWithCustomerExcludingAssessedTax" abstract="false" name="PercentOfRevenueFromContractWithCustomerExcludingAssessedTax" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="shc_PercentOfPropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization" abstract="false" name="PercentOfPropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
</xs:schema>
