<?xml version="1.0" encoding="US-ASCII"?>
<!--XBRL Document Created with Wdesk from Workiva-->
<!-- -->
<xsd:schema attributeFormDefault="unqualified" elementFormDefault="qualified" targetNamespace="http://www.nacg.ca/20151231" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:noa="http://www.nacg.ca/20151231" xmlns:nonnum="http://www.xbrl.org/dtr/type/non-numeric" xmlns:num="http://www.xbrl.org/dtr/type/numeric" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <xsd:import namespace="http://fasb.org/us-gaap/2015-01-31" schemaLocation="http://xbrl.fasb.org/us-gaap/2015/elts/us-gaap-2015-01-31.xsd" />
  <xsd:import namespace="http://fasb.org/us-roles/2015-01-31" schemaLocation="http://xbrl.fasb.org/us-gaap/2015/elts/us-roles-2015-01-31.xsd" />
  <xsd:import namespace="http://fasb.org/us-types/2015-01-31" schemaLocation="http://xbrl.fasb.org/us-gaap/2015/elts/us-types-2015-01-31.xsd" />
  <xsd:import namespace="http://www.xbrl.org/2003/instance" schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd" />
  <xsd:import namespace="http://www.xbrl.org/2003/linkbase" schemaLocation="http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" />
  <xsd:import namespace="http://www.xbrl.org/2009/arcrole/fact-explanatoryFact" schemaLocation="http://www.xbrl.org/lrr/arcrole/factExplanatory-2009-12-16.xsd" />
  <xsd:import namespace="http://www.xbrl.org/2009/role/negated" schemaLocation="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd" />
  <xsd:import namespace="http://www.xbrl.org/2009/role/net" schemaLocation="http://www.xbrl.org/lrr/role/net-2009-12-16.xsd" />
  <xsd:import namespace="http://www.xbrl.org/dtr/type/non-numeric" schemaLocation="http://www.xbrl.org/dtr/type/nonNumeric-2009-12-16.xsd" />
  <xsd:import namespace="http://www.xbrl.org/dtr/type/numeric" schemaLocation="http://www.xbrl.org/dtr/type/numeric-2009-12-16.xsd" />
  <xsd:import namespace="http://xbrl.org/2005/xbrldt" schemaLocation="http://www.xbrl.org/2005/xbrldt-2005.xsd" />
  <xsd:import namespace="http://xbrl.sec.gov/country/2013-01-31" schemaLocation="http://xbrl.sec.gov/country/2013/country-2013-01-31.xsd" />
  <xsd:import namespace="http://xbrl.sec.gov/currency/2014-01-31" schemaLocation="http://xbrl.sec.gov/currency/2014/currency-2014-01-31.xsd" />
  <xsd:import namespace="http://xbrl.sec.gov/dei/2014-01-31" schemaLocation="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd" />
  <xsd:import namespace="http://xbrl.sec.gov/exch/2015-01-31" schemaLocation="http://xbrl.sec.gov/exch/2015/exch-2015-01-31.xsd" />
  <xsd:import namespace="http://xbrl.sec.gov/invest/2013-01-31" schemaLocation="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd" />
  <xsd:import namespace="http://xbrl.sec.gov/naics/2011-01-31" schemaLocation="http://xbrl.sec.gov/naics/2011/naics-2011-01-31.xsd" />
  <xsd:import namespace="http://xbrl.sec.gov/sic/2011-01-31" schemaLocation="http://xbrl.sec.gov/sic/2011/sic-2011-01-31.xsd" />
  <xsd:import namespace="http://xbrl.sec.gov/stpr/2011-01-31" schemaLocation="http://xbrl.sec.gov/stpr/2011/stpr-2011-01-31.xsd" />
  <xsd:annotation>
    <xsd:appinfo>
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="noa-20151231_cal.xml" xlink:role="http://www.xbrl.org/2003/role/calculationLinkbaseRef" xlink:type="simple" />
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="noa-20151231_def.xml" xlink:role="http://www.xbrl.org/2003/role/definitionLinkbaseRef" xlink:type="simple" />
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="noa-20151231_lab.xml" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:type="simple" />
      <link:linkbaseRef xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="noa-20151231_pre.xml" xlink:role="http://www.xbrl.org/2003/role/presentationLinkbaseRef" xlink:type="simple" />
      <link:roleType id="AccountingPronouncementsRecentlyAdopted" roleURI="http://www.nacg.ca/role/AccountingPronouncementsRecentlyAdopted">
        <link:definition>2103100 - Disclosure - Accounting pronouncements recently adopted</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="AccountingPronouncementsRecentlyAdoptedAccountingPronouncementsRecentlyAdoptedDetails" roleURI="http://www.nacg.ca/role/AccountingPronouncementsRecentlyAdoptedAccountingPronouncementsRecentlyAdoptedDetails">
        <link:definition>2403401 - Disclosure - Accounting pronouncements recently adopted Accounting pronouncements recently adopted (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="AccountsReceivable" roleURI="http://www.nacg.ca/role/AccountsReceivable">
        <link:definition>2105100 - Disclosure - Accounts receivable</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="AccountsReceivableDetails" roleURI="http://www.nacg.ca/role/AccountsReceivableDetails">
        <link:definition>2405402 - Disclosure - Accounts receivable (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="AccountsReceivableTables" roleURI="http://www.nacg.ca/role/AccountsReceivableTables">
        <link:definition>2305301 - Disclosure - Accounts receivable (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="AccruedLiabilities" roleURI="http://www.nacg.ca/role/AccruedLiabilities">
        <link:definition>2116100 - Disclosure - Accrued liabilities</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="AccruedLiabilitiesDetails" roleURI="http://www.nacg.ca/role/AccruedLiabilitiesDetails">
        <link:definition>2416402 - Disclosure - Accrued liabilities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="AccruedLiabilitiesTables" roleURI="http://www.nacg.ca/role/AccruedLiabilitiesTables">
        <link:definition>2316301 - Disclosure - Accrued liabilities (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="AssetsHeldForSale" roleURI="http://www.nacg.ca/role/AssetsHeldForSale">
        <link:definition>2111100 - Disclosure - Assets held for sale</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="AssetsHeldForSaleDetails" roleURI="http://www.nacg.ca/role/AssetsHeldForSaleDetails">
        <link:definition>2411402 - Disclosure - Assets held for sale (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="AssetsHeldForSaleTables" roleURI="http://www.nacg.ca/role/AssetsHeldForSaleTables">
        <link:definition>2311301 - Disclosure - Assets held for sale (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CapitalLeaseObligations" roleURI="http://www.nacg.ca/role/CapitalLeaseObligations">
        <link:definition>2118100 - Disclosure - Capital lease obligations</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CapitalLeaseObligationsDetails" roleURI="http://www.nacg.ca/role/CapitalLeaseObligationsDetails">
        <link:definition>2418402 - Disclosure - Capital lease obligations (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CapitalLeaseObligationsTables" roleURI="http://www.nacg.ca/role/CapitalLeaseObligationsTables">
        <link:definition>2318301 - Disclosure - Capital lease obligations (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ClaimsRevenue" roleURI="http://www.nacg.ca/role/ClaimsRevenue">
        <link:definition>2128100 - Disclosure - Claims revenue</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ClaimsRevenueDetails" roleURI="http://www.nacg.ca/role/ClaimsRevenueDetails">
        <link:definition>2428402 - Disclosure - Claims revenue (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ClaimsRevenueTables" roleURI="http://www.nacg.ca/role/ClaimsRevenueTables">
        <link:definition>2328301 - Disclosure - Claims revenue (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="Commitments" roleURI="http://www.nacg.ca/role/Commitments">
        <link:definition>2122100 - Disclosure - Commitments</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CommitmentsDetails" roleURI="http://www.nacg.ca/role/CommitmentsDetails">
        <link:definition>2422402 - Disclosure - Commitments (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CommitmentsTables" roleURI="http://www.nacg.ca/role/CommitmentsTables">
        <link:definition>2322301 - Disclosure - Commitments (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ComparativeFigures" roleURI="http://www.nacg.ca/role/ComparativeFigures">
        <link:definition>2131100 - Disclosure - Comparative figures</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ConsolidatedBalanceSheets" roleURI="http://www.nacg.ca/role/ConsolidatedBalanceSheets">
        <link:definition>1001000 - Statement - Consolidated Balance Sheets</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ConsolidatedBalanceSheetsParenthetical" roleURI="http://www.nacg.ca/role/ConsolidatedBalanceSheetsParenthetical">
        <link:definition>1001501 - Statement - Consolidated Balance Sheets (Parenthetical)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ConsolidatedStatementsOfCashFlows" roleURI="http://www.nacg.ca/role/ConsolidatedStatementsOfCashFlows">
        <link:definition>1004000 - Statement - Consolidated Statements of Cash Flows</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ConsolidatedStatementsOfChangesInShareholdersEquity" roleURI="http://www.nacg.ca/role/ConsolidatedStatementsOfChangesInShareholdersEquity">
        <link:definition>1003000 - Statement - Consolidated Statements of Changes in Shareholders' Equity</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ConsolidatedStatementsOfOperationsAndComprehensiveLossIncome" roleURI="http://www.nacg.ca/role/ConsolidatedStatementsOfOperationsAndComprehensiveLossIncome">
        <link:definition>1002000 - Statement - Consolidated Statements of Operations and Comprehensive Loss (Income)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="Contingencies" roleURI="http://www.nacg.ca/role/Contingencies">
        <link:definition>2123100 - Disclosure - Contingencies</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CostsIncurredAndEstimatedEarningsNetOfBillingsOnUncompletedContracts" roleURI="http://www.nacg.ca/role/CostsIncurredAndEstimatedEarningsNetOfBillingsOnUncompletedContracts">
        <link:definition>2106100 - Disclosure - Costs incurred and estimated earnings net of billings on uncompleted contracts</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CostsIncurredAndEstimatedEarningsNetOfBillingsOnUncompletedContractsDetails" roleURI="http://www.nacg.ca/role/CostsIncurredAndEstimatedEarningsNetOfBillingsOnUncompletedContractsDetails">
        <link:definition>2406402 - Disclosure - Costs incurred and estimated earnings net of billings on uncompleted contracts (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CostsIncurredAndEstimatedEarningsNetOfBillingsOnUncompletedContractsTables" roleURI="http://www.nacg.ca/role/CostsIncurredAndEstimatedEarningsNetOfBillingsOnUncompletedContractsTables">
        <link:definition>2306301 - Disclosure - Costs incurred and estimated earnings net of billings on uncompleted contracts (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DiscontinuedOperations" roleURI="http://www.nacg.ca/role/DiscontinuedOperations">
        <link:definition>2125100 - Disclosure - Discontinued operations</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DiscontinuedOperationsDetails" roleURI="http://www.nacg.ca/role/DiscontinuedOperationsDetails">
        <link:definition>2425402 - Disclosure - Discontinued operations (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DiscontinuedOperationsDiscontinuedOperationsTables" roleURI="http://www.nacg.ca/role/DiscontinuedOperationsDiscontinuedOperationsTables">
        <link:definition>2325301 - Disclosure - Discontinued operations Discontinued operations (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DocumentAndEntityInformation" roleURI="http://www.nacg.ca/role/DocumentAndEntityInformation">
        <link:definition>0001000 - Document - Document and Entity Information</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EmployeeBenefitPlans" roleURI="http://www.nacg.ca/role/EmployeeBenefitPlans">
        <link:definition>2130100 - Disclosure - Employee benefit plans</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EmployeeBenefitPlansDetails" roleURI="http://www.nacg.ca/role/EmployeeBenefitPlansDetails">
        <link:definition>2430401 - Disclosure - Employee benefit plans (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="FinancialInstrumentsAndRiskManagement" roleURI="http://www.nacg.ca/role/FinancialInstrumentsAndRiskManagement">
        <link:definition>2119100 - Disclosure - Financial instruments and risk management</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="FinancialInstrumentsAndRiskManagementAssetsHeldForSaleDetails" roleURI="http://www.nacg.ca/role/FinancialInstrumentsAndRiskManagementAssetsHeldForSaleDetails">
        <link:definition>2419403 - Disclosure - Financial instruments and risk management - Assets held-for-sale (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="FinancialInstrumentsAndRiskManagementFinancialInstrumentsDetails" roleURI="http://www.nacg.ca/role/FinancialInstrumentsAndRiskManagementFinancialInstrumentsDetails">
        <link:definition>2419402 - Disclosure - Financial instruments and risk management - Financial instruments (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="FinancialInstrumentsAndRiskManagementMaximumCreditExposureDetails" roleURI="http://www.nacg.ca/role/FinancialInstrumentsAndRiskManagementMaximumCreditExposureDetails">
        <link:definition>2419405 - Disclosure - Financial instruments and risk management - Maximum credit exposure (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="FinancialInstrumentsAndRiskManagementRiskManagementDetails" roleURI="http://www.nacg.ca/role/FinancialInstrumentsAndRiskManagementRiskManagementDetails">
        <link:definition>2419404 - Disclosure - Financial instruments and risk management - Risk management (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="FinancialInstrumentsAndRiskManagementTables" roleURI="http://www.nacg.ca/role/FinancialInstrumentsAndRiskManagementTables">
        <link:definition>2319301 - Disclosure - Financial instruments and risk management (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="FinancialInstrumentsAndRiskManagementTradeReceivablesDetails" roleURI="http://www.nacg.ca/role/FinancialInstrumentsAndRiskManagementTradeReceivablesDetails">
        <link:definition>2419406 - Disclosure - Financial instruments and risk management - Trade receivables (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IncomeTaxes" roleURI="http://www.nacg.ca/role/IncomeTaxes">
        <link:definition>2112100 - Disclosure - Income taxes</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IncomeTaxesIncomeTaxesDeferredTaxAssetsAndLiabilitiesDetails" roleURI="http://www.nacg.ca/role/IncomeTaxesIncomeTaxesDeferredTaxAssetsAndLiabilitiesDetails">
        <link:definition>2412403 - Disclosure - Income taxes Income Taxes - Deferred Tax Assets and Liabilities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IncomeTaxesIncomeTaxesExpenseBenefitDetails" roleURI="http://www.nacg.ca/role/IncomeTaxesIncomeTaxesExpenseBenefitDetails">
        <link:definition>2412402 - Disclosure - Income taxes Income Taxes - Expense (Benefit) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IncomeTaxesIncomeTaxesExpirationOfNonCapitalLossesForIncomeTaxPurposesDetails" roleURI="http://www.nacg.ca/role/IncomeTaxesIncomeTaxesExpirationOfNonCapitalLossesForIncomeTaxPurposesDetails">
        <link:definition>2412405 - Disclosure - Income taxes Income Taxes - Expiration of Non-Capital Losses for Income Tax Purposes (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IncomeTaxesNarrativedetails" roleURI="http://www.nacg.ca/role/IncomeTaxesNarrativedetails">
        <link:definition>2412404 - Disclosure - Income taxes Narrative(Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IncomeTaxesTables" roleURI="http://www.nacg.ca/role/IncomeTaxesTables">
        <link:definition>2312301 - Disclosure - Income taxes (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="InterestExpense" roleURI="http://www.nacg.ca/role/InterestExpense">
        <link:definition>2124100 - Disclosure - Interest expense</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="InterestExpenseDetails" roleURI="http://www.nacg.ca/role/InterestExpenseDetails">
        <link:definition>2424402 - Disclosure - Interest expense (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="InterestExpenseTables" roleURI="http://www.nacg.ca/role/InterestExpenseTables">
        <link:definition>2324301 - Disclosure - Interest expense (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="LongTermDebt" roleURI="http://www.nacg.ca/role/LongTermDebt">
        <link:definition>2117100 - Disclosure - Long term debt</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="LongTermDebtCreditFacilitiesDetails" roleURI="http://www.nacg.ca/role/LongTermDebtCreditFacilitiesDetails">
        <link:definition>2417403 - Disclosure - Long term debt - Credit facilities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="LongTermDebtDetails" roleURI="http://www.nacg.ca/role/LongTermDebtDetails">
        <link:definition>2417402 - Disclosure - Long term debt (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="LongTermDebtSeries1DebenturesDetails" roleURI="http://www.nacg.ca/role/LongTermDebtSeries1DebenturesDetails">
        <link:definition>2417404 - Disclosure - Long term debt - Series 1 Debentures (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="LongTermDebtTables" roleURI="http://www.nacg.ca/role/LongTermDebtTables">
        <link:definition>2317301 - Disclosure - Long term debt (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="NatureOfOperations" roleURI="http://www.nacg.ca/role/NatureOfOperations">
        <link:definition>2101100 - Disclosure - Nature of operations</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="OtherAssets" roleURI="http://www.nacg.ca/role/OtherAssets">
        <link:definition>2115100 - Disclosure - Other assets</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="OtherAssetsDeferredFinancingCostsDetails" roleURI="http://www.nacg.ca/role/OtherAssetsDeferredFinancingCostsDetails">
        <link:definition>2415404 - Disclosure - Other assets - Deferred financing costs (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="OtherAssetsDeferredLeaseInducementsAssetDetails" roleURI="http://www.nacg.ca/role/OtherAssetsDeferredLeaseInducementsAssetDetails">
        <link:definition>2415405 - Disclosure - Other assets - Deferred lease inducements asset (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="OtherAssetsDetails" roleURI="http://www.nacg.ca/role/OtherAssetsDetails">
        <link:definition>2415402 - Disclosure - Other assets (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="OtherAssetsIntangibleAssetsDetails" roleURI="http://www.nacg.ca/role/OtherAssetsIntangibleAssetsDetails">
        <link:definition>2415403 - Disclosure - Other assets - Intangible assets (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="OtherAssetsIntangibleAssetsDetailsCalc2" roleURI="http://www.nacg.ca/role/OtherAssetsIntangibleAssetsDetailsCalc2">
        <link:definition>2415403 - Disclosure - Other assets - Intangible assets (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="OtherAssetsTables" roleURI="http://www.nacg.ca/role/OtherAssetsTables">
        <link:definition>2315301 - Disclosure - Other assets (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="OtherInformation" roleURI="http://www.nacg.ca/role/OtherInformation">
        <link:definition>2127100 - Disclosure - Other information</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="OtherInformationNonCashDetails" roleURI="http://www.nacg.ca/role/OtherInformationNonCashDetails">
        <link:definition>2427403 - Disclosure - Other information - Non-cash (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="OtherInformationOtherInformationSupplementalCashFlowInformationDetails" roleURI="http://www.nacg.ca/role/OtherInformationOtherInformationSupplementalCashFlowInformationDetails">
        <link:definition>2427402 - Disclosure - Other information Other information - Supplemental cash flow information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="OtherInformationTables" roleURI="http://www.nacg.ca/role/OtherInformationTables">
        <link:definition>2327301 - Disclosure - Other information (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="OtherLongTermObligations" roleURI="http://www.nacg.ca/role/OtherLongTermObligations">
        <link:definition>2120100 - Disclosure - Other long term obligations</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="OtherLongTermObligationsDetails" roleURI="http://www.nacg.ca/role/OtherLongTermObligationsDetails">
        <link:definition>2420402 - Disclosure - Other long term obligations (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="OtherLongTermObligationsOtherLongTermObligationsAdditionalDisclosuresDetails" roleURI="http://www.nacg.ca/role/OtherLongTermObligationsOtherLongTermObligationsAdditionalDisclosuresDetails">
        <link:definition>2420403 - Disclosure - Other long term obligations Other long term obligations - Additional disclosures (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="OtherLongTermObligationsTables" roleURI="http://www.nacg.ca/role/OtherLongTermObligationsTables">
        <link:definition>2320301 - Disclosure - Other long term obligations (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PlantAndEquipment" roleURI="http://www.nacg.ca/role/PlantAndEquipment">
        <link:definition>2113100 - Disclosure - Plant and equipment</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PlantAndEquipmentDetails" roleURI="http://www.nacg.ca/role/PlantAndEquipmentDetails">
        <link:definition>2413402 - Disclosure - Plant and equipment (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PlantAndEquipmentTables" roleURI="http://www.nacg.ca/role/PlantAndEquipmentTables">
        <link:definition>2313301 - Disclosure - Plant and equipment (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PrepaidExpensesAndDeposits" roleURI="http://www.nacg.ca/role/PrepaidExpensesAndDeposits">
        <link:definition>2108100 - Disclosure - Prepaid expenses and deposits</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PrepaidExpensesAndDepositsDetails" roleURI="http://www.nacg.ca/role/PrepaidExpensesAndDepositsDetails">
        <link:definition>2408402 - Disclosure - Prepaid expenses and deposits (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PrepaidExpensesAndDepositsTables" roleURI="http://www.nacg.ca/role/PrepaidExpensesAndDepositsTables">
        <link:definition>2308301 - Disclosure - Prepaid expenses and deposits (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="RecentAccountingPronouncementsNotYetAdopted" roleURI="http://www.nacg.ca/role/RecentAccountingPronouncementsNotYetAdopted">
        <link:definition>2104100 - Disclosure - Recent accounting pronouncements not yet adopted</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="Shares" roleURI="http://www.nacg.ca/role/Shares">
        <link:definition>2121100 - Disclosure - Shares</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SharesAntidilutiveSecuritiesDetails" roleURI="http://www.nacg.ca/role/SharesAntidilutiveSecuritiesDetails">
        <link:definition>2421403 - Disclosure - Shares - Antidilutive securities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SharesDividendsDetails" roleURI="http://www.nacg.ca/role/SharesDividendsDetails">
        <link:definition>2421405 - Disclosure - Shares - Dividends (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SharesSharePurchaseProgramDetails" roleURI="http://www.nacg.ca/role/SharesSharePurchaseProgramDetails">
        <link:definition>2421404 - Disclosure - Shares - Share Purchase Program (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SharesTables" roleURI="http://www.nacg.ca/role/SharesTables">
        <link:definition>2321301 - Disclosure - Shares (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SharesVotingCommonSharesDetails" roleURI="http://www.nacg.ca/role/SharesVotingCommonSharesDetails">
        <link:definition>2421402 - Disclosure - Shares - Voting common shares (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SignificantAccountingPolicies" roleURI="http://www.nacg.ca/role/SignificantAccountingPolicies">
        <link:definition>2102100 - Disclosure - Significant accounting policies</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SignificantAccountingPoliciesIntangibleAssetsDetails" roleURI="http://www.nacg.ca/role/SignificantAccountingPoliciesIntangibleAssetsDetails">
        <link:definition>2402405 - Disclosure - Significant accounting policies - Intangible Assets (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SignificantAccountingPoliciesPolicies" roleURI="http://www.nacg.ca/role/SignificantAccountingPoliciesPolicies">
        <link:definition>2202201 - Disclosure - Significant accounting policies (Policies)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SignificantAccountingPoliciesPropertyPlantAndEquipmentDetails" roleURI="http://www.nacg.ca/role/SignificantAccountingPoliciesPropertyPlantAndEquipmentDetails">
        <link:definition>2402404 - Disclosure - Significant accounting policies - Property, Plant and Equipment (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SignificantAccountingPoliciesRevenueRecognitionDetails" roleURI="http://www.nacg.ca/role/SignificantAccountingPoliciesRevenueRecognitionDetails">
        <link:definition>2402403 - Disclosure - Significant accounting policies - Revenue Recognition (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SignificantAccountingPoliciesStockBasedCompensationDetails" roleURI="http://www.nacg.ca/role/SignificantAccountingPoliciesStockBasedCompensationDetails">
        <link:definition>2402406 - Disclosure - Significant accounting policies - Stock-based Compensation (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SignificantAccountingPoliciesTables" roleURI="http://www.nacg.ca/role/SignificantAccountingPoliciesTables">
        <link:definition>2302302 - Disclosure - Significant accounting policies (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="StockBasedCompensation" roleURI="http://www.nacg.ca/role/StockBasedCompensation">
        <link:definition>2126100 - Disclosure - Stock-based compensation</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="StockBasedCompensationOptionsByExercisePriceRangeDetails" roleURI="http://www.nacg.ca/role/StockBasedCompensationOptionsByExercisePriceRangeDetails">
        <link:definition>2426404 - Disclosure - Stock-based compensation - Options by exercise price range (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="StockBasedCompensationShareOptionsPlanDetails" roleURI="http://www.nacg.ca/role/StockBasedCompensationShareOptionsPlanDetails">
        <link:definition>2426403 - Disclosure - Stock-based compensation - Share options plan (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="StockBasedCompensationStockBasedCompensationDeferredStockUnitPlanDetails" roleURI="http://www.nacg.ca/role/StockBasedCompensationStockBasedCompensationDeferredStockUnitPlanDetails">
        <link:definition>2426408 - Disclosure - Stock-based compensation Stock-based compensation - Deferred stock unit plan (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="StockBasedCompensationStockBasedCompensationExpensesDetails" roleURI="http://www.nacg.ca/role/StockBasedCompensationStockBasedCompensationExpensesDetails">
        <link:definition>2426402 - Disclosure - Stock-based compensation - Stock-based compensation expenses (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="StockBasedCompensationStockBasedCompensationPerformanceRestrictedShareUnitsDetails" roleURI="http://www.nacg.ca/role/StockBasedCompensationStockBasedCompensationPerformanceRestrictedShareUnitsDetails">
        <link:definition>2426407 - Disclosure - Stock-based compensation Stock-based compensation - Performance restricted share units (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="StockBasedCompensationStockBasedCompensationRestrictedShareUnitPlanDetails" roleURI="http://www.nacg.ca/role/StockBasedCompensationStockBasedCompensationRestrictedShareUnitPlanDetails">
        <link:definition>2426406 - Disclosure - Stock-based compensation Stock-based compensation - Restricted share unit plan (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="StockBasedCompensationStockBasedCompensationSeniorExecutiveStockOptionPlanDetails" roleURI="http://www.nacg.ca/role/StockBasedCompensationStockBasedCompensationSeniorExecutiveStockOptionPlanDetails">
        <link:definition>2426405 - Disclosure - Stock-based compensation Stock-based compensation - Senior executive stock option plan (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="StockBasedCompensationTables" roleURI="http://www.nacg.ca/role/StockBasedCompensationTables">
        <link:definition>2326301 - Disclosure - Stock-based compensation (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="StockBasedCompensationTextualsDetails" roleURI="http://www.nacg.ca/role/StockBasedCompensationTextualsDetails">
        <link:definition>2426409 - Disclosure - Stock-based compensation - Textuals (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SubsequentEvents" roleURI="http://www.nacg.ca/role/SubsequentEvents">
        <link:definition>2132100 - Disclosure - Subsequent events</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SubsequentEventsDetails" roleURI="http://www.nacg.ca/role/SubsequentEventsDetails">
        <link:definition>2432401 - Disclosure - Subsequent events (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
    </xsd:appinfo>
  </xsd:annotation>
  <xsd:element id="noa_AccountsReceivable1To30DaysPastDue" name="AccountsReceivable1To30DaysPastDue" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="noa_AccountsReceivable31To60DaysPastDue" name="AccountsReceivable31To60DaysPastDue" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="noa_AccountsReceivableAndUnbilledRevenueMember" name="AccountsReceivableAndUnbilledRevenueMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_AccountsReceivableCurrent" name="AccountsReceivableCurrent" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="noa_AccountsReceivableGeneralPaymentTerms" name="AccountsReceivableGeneralPaymentTerms" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_AccountsReceivableGreaterThan60DaysPastDue" name="AccountsReceivableGreaterThan60DaysPastDue" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="noa_AccountsReceivableHoldbacksGrossCurrent" name="AccountsReceivableHoldbacksGrossCurrent" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="noa_AccountsReceivableMaximumHoldbackPercentage" name="AccountsReceivableMaximumHoldbackPercentage" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_AcquisitionOfPropertyPlantAndEquipmentMember" name="AcquisitionOfPropertyPlantAndEquipmentMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_AdditionsToAssetsHeldForSale" name="AdditionsToAssetsHeldForSale" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="noa_AdjustmentsToAdditionalPaidInCapitalRepurchaseOfSharesToSettleStockAwardPlan" name="AdjustmentsToAdditionalPaidInCapitalRepurchaseOfSharesToSettleStockAwardPlan" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="noa_AllowanceForDoubtfulAccountsRollforwardTableTextBlock" name="AllowanceForDoubtfulAccountsRollforwardTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_AmortizationonLeaseIncentiveReceivable" name="AmortizationonLeaseIncentiveReceivable" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="noa_AssetRetirementObligationEstimatedUndiscountedFutureCashFlowToSettle" name="AssetRetirementObligationEstimatedUndiscountedFutureCashFlowToSettle" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="noa_AssetRetirementObligationRiskFreeRateUsedToMeasure" name="AssetRetirementObligationRiskFreeRateUsedToMeasure" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_BalanceSheetClassificationPolicyPolicyTextBlock" name="BalanceSheetClassificationPolicyPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_BillingsOnUncompletedContractsOrPrograms" name="BillingsOnUncompletedContractsOrPrograms" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="noa_CapitalLeaseObligationsFairValueDisclosure" name="CapitalLeaseObligationsFairValueDisclosure" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="noa_CashFlowNonCashTransactionsAbstract" name="CashFlowNonCashTransactionsAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_CashFlowsNonCashTransactionsRelatedToDiscontinuedOperationsAbstract" name="CashFlowsNonCashTransactionsRelatedToDiscontinuedOperationsAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_CashPaidDuringYearAbstract" name="CashPaidDuringYearAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_CashReceivedDuringYearAbstract" name="CashReceivedDuringYearAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_CashSettlementOfRestrictedShareUnitPlan" name="CashSettlementOfRestrictedShareUnitPlan" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="noa_ClaimsRevenueDisclosureTextBlock" name="ClaimsRevenueDisclosureTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_Commitments" name="Commitments" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="noa_CommitmentsDisclosureAbstract" name="CommitmentsDisclosureAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_CommonStockShareAuthorized" name="CommonStockShareAuthorized" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_CommonStockSharesOutstandingNetofTreasuryShares" name="CommonStockSharesOutstandingNetofTreasuryShares" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="noa_ComparativeFiguresAbstract" name="ComparativeFiguresAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_ComparativeFiguresDisclosureTextBlock" name="ComparativeFiguresDisclosureTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_Contingencies" name="Contingencies" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="noa_ContingenciesDisclosureAbstract" name="ContingenciesDisclosureAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_ContractbasedequipmentMember" name="ContractbasedequipmentMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_CostsIncurredOnUncompletedContractsOrPrograms" name="CostsIncurredOnUncompletedContractsOrPrograms" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="noa_CustomerBMember" name="CustomerBMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_CustomerCMember" name="CustomerCMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_CustomerDMember" name="CustomerDMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_CustomerEMember" name="CustomerEMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_CustomerFMember" name="CustomerFMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_CustomerGMember" name="CustomerGMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_CustomerHMember" name="CustomerHMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_CustomerIMember" name="CustomerIMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_CustomerJMember" name="CustomerJMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_CustomerMember" name="CustomerMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_DebtInstrumentBasisSpreadonVariableRateAdjustment" name="DebtInstrumentBasisSpreadonVariableRateAdjustment" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_DebtInstrumentCovenantTermsMaximumFaceValueOutstanding" name="DebtInstrumentCovenantTermsMaximumFaceValueOutstanding" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="noa_DebtInstrumentCovenantTermsMinimumFixedChargeRatio" name="DebtInstrumentCovenantTermsMinimumFixedChargeRatio" nillable="true" substitutionGroup="xbrli:item" type="xbrli:pureItemType" xbrli:periodType="instant" />
  <xsd:element id="noa_DebtInstrumentRedemptionAuthorizedAmount" name="DebtInstrumentRedemptionAuthorizedAmount" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="noa_DebtInstrumentRedemptionPremiumUponChangeofControlPercentage" name="DebtInstrumentRedemptionPremiumUponChangeofControlPercentage" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="instant" />
  <xsd:element id="noa_DebtModificationCosts" name="DebtModificationCosts" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="noa_DebtinstrumentRepaymentPercentofExcessCashFlow" name="DebtinstrumentRepaymentPercentofExcessCashFlow" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_DeferredGainonSaleLeasebackCurrent" name="DeferredGainonSaleLeasebackCurrent" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="noa_DeferredGainonSaleLeasebackRollForward" name="DeferredGainonSaleLeasebackRollForward" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_DeferredLeaseInducementsAssetRollForward" name="DeferredLeaseInducementsAssetRollForward" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_DeferredShareUnitPlanMember" name="DeferredShareUnitPlanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_DeferredStockUnitsDSUsMember" name="DeferredStockUnitsDSUsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_DeferredStockUnitsDividendEquivalentRightsMember" name="DeferredStockUnitsDividendEquivalentRightsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_DeferredTaxAssetsBillingsInExcessOfCosts" name="DeferredTaxAssetsBillingsInExcessOfCosts" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="noa_DeferredTaxAssetsCapitalLeaseObligations" name="DeferredTaxAssetsCapitalLeaseObligations" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="noa_DeferredTaxAssetsDeferredFinancingCosts" name="DeferredTaxAssetsDeferredFinancingCosts" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="noa_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsDeferredLeaseIncentives" name="DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsDeferredLeaseIncentives" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="noa_DeferredTaxLiabilitiesAccountsReceivableHoldbacks" name="DeferredTaxLiabilitiesAccountsReceivableHoldbacks" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="noa_DeferredTaxLiabilitiesAssetsHeldForSale" name="DeferredTaxLiabilitiesAssetsHeldForSale" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="noa_DeferredTaxLiabilitiesUnbilledRevenueAndUncertifiedRevenueIncludedInAccountsReceivable" name="DeferredTaxLiabilitiesUnbilledRevenueAndUncertifiedRevenueIncludedInAccountsReceivable" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="noa_DepreciationExpenseMember" name="DepreciationExpenseMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_DirectorsDeferredShareUnitPlanMember" name="DirectorsDeferredShareUnitPlanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_DiscontinuedOperationTaxEffectofDiscontinuedOperationCurrent" name="DiscontinuedOperationTaxEffectofDiscontinuedOperationCurrent" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="noa_DiscontinuedOperationTaxEffectofDiscontinuedOperationDeferred" name="DiscontinuedOperationTaxEffectofDiscontinuedOperationDeferred" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="noa_DisposalGroupIncludingDiscontinuedOperationAmortizationOfIntangibleAssets" name="DisposalGroupIncludingDiscontinuedOperationAmortizationOfIntangibleAssets" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="noa_DisposalGroupIncludingDiscontinuedOperationContingentConsiderationProceeds" name="DisposalGroupIncludingDiscontinuedOperationContingentConsiderationProceeds" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="noa_DisposalGroupIncludingDiscontinuedOperationContingentConsiderationProceedsPeriod" name="DisposalGroupIncludingDiscontinuedOperationContingentConsiderationProceedsPeriod" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_DisposalGroupIncludingDiscontinuedOperationGainLossOnSaleOfInventory" name="DisposalGroupIncludingDiscontinuedOperationGainLossOnSaleOfInventory" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="noa_DisposalGroupIncludingDiscontinuedOperationsDepreciation" name="DisposalGroupIncludingDiscontinuedOperationsDepreciation" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="noa_DisposalGroupIncludingDiscontinuedOperationsEquipmentCosts" name="DisposalGroupIncludingDiscontinuedOperationsEquipmentCosts" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="noa_DisposalGroupIncludingDiscontinuedOperationsGainLossonDisposalofAssetsandLiabilities" name="DisposalGroupIncludingDiscontinuedOperationsGainLossonDisposalofAssetsandLiabilities" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="noa_DividendsPayableAnnualAggregateDividend" name="DividendsPayableAnnualAggregateDividend" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="noa_DocumentAndEntityInformationAbstract" name="DocumentAndEntityInformationAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseNondeductiblePortionofCapitalLossesAmount" name="EffectiveIncomeTaxRateReconciliationNondeductibleExpenseNondeductiblePortionofCapitalLossesAmount" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_EightPointFiftyEightMember" name="EightPointFiftyEightMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_EightPointTwentyEightMember" name="EightPointTwentyEightMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_EquityClassifiedDeferredStockUnitPlanMember" name="EquityClassifiedDeferredStockUnitPlanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_EquityClassifiedRestrictedShareUnitPlanMember" name="EquityClassifiedRestrictedShareUnitPlanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_FairValueConcentrationOfRiskOtherReceivables" name="FairValueConcentrationOfRiskOtherReceivables" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="noa_FairValueConcentrationOfRiskTradeAccountsReceivable" name="FairValueConcentrationOfRiskTradeAccountsReceivable" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="noa_FinancialInstrumentsAndRiskManagementTextBlock" name="FinancialInstrumentsAndRiskManagementTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_FivePointNinetyOneMember" name="FivePointNinetyOneMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_FivePointZeroMember" name="FivePointZeroMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_FourPointNinetyMember" name="FourPointNinetyMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_IncomeTaxReconciliationIncomeTaxAdjustmentsAndReassessments" name="IncomeTaxReconciliationIncomeTaxAdjustmentsAndReassessments" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="noa_IncreaseDecreaseInAccruedRentExpense" name="IncreaseDecreaseInAccruedRentExpense" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="noa_IncreaseDecreaseInAccruedShareBasedCompensationLiabilities" name="IncreaseDecreaseInAccruedShareBasedCompensationLiabilities" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="noa_InterestExpenseAdjustmentduetoInterestRateChange" name="InterestExpenseAdjustmentduetoInterestRateChange" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="noa_InterestExpenseDisclosureTextBlock" name="InterestExpenseDisclosureTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_July2014GrantMember" name="July2014GrantMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_July2015GrantMember" name="July2015GrantMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_LeaseIncentivePayableNoncurrent" name="LeaseIncentivePayableNoncurrent" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="noa_LeaseIncentivePayableRollForward" name="LeaseIncentivePayableRollForward" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_LeaseIncentiveReceivableAdditions" name="LeaseIncentiveReceivableAdditions" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_LiabilityClassifiedDeferredStockUnitPlanMember" name="LiabilityClassifiedDeferredStockUnitPlanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_LiabilityClassifiedRestrictedShareUnitPlanMember" name="LiabilityClassifiedRestrictedShareUnitPlanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_LongLivedAssetsHeldForSaleDisclosureTextBlock" name="LongLivedAssetsHeldForSaleDisclosureTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_LongLivedAssetsHeldForSalePolicyPolicyTextBlock" name="LongLivedAssetsHeldForSalePolicyPolicyTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_MajorComponentPartsInUseMember" name="MajorComponentPartsInUseMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_NCIBStockPurchaseProgramMember" name="NCIBStockPurchaseProgramMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_NinePointThrirtyThreeMember" name="NinePointThrirtyThreeMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_NoncashTransactionIncreaseDecreaseinAccountsPayableChangetoLeaseInducementPayable" name="NoncashTransactionIncreaseDecreaseinAccountsPayableChangetoLeaseInducementPayable" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="noa_NoncashTransactionIncreaseDecreaseinAccountsPayablePurchaseofIntangibles" name="NoncashTransactionIncreaseDecreaseinAccountsPayablePurchaseofIntangibles" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="noa_NoncashTransactionIncreaseDecreaseinAccruedLiabilitiesDividendsPayable" name="NoncashTransactionIncreaseDecreaseinAccruedLiabilitiesDividendsPayable" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="noa_NoncashTransactionIncreaseDecreaseinAccruedLiabilitiesSaleLeasebackCurrent" name="NoncashTransactionIncreaseDecreaseinAccruedLiabilitiesSaleLeasebackCurrent" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="noa_NoncashTransactionIncreaseDecreaseinEquipmentLeaseLiabilitiesCurrent" name="NoncashTransactionIncreaseDecreaseinEquipmentLeaseLiabilitiesCurrent" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="noa_NoncashTransactionIncreaseDecreaseinEquipmentLeaseLiabilitiesNoncurrent" name="NoncashTransactionIncreaseDecreaseinEquipmentLeaseLiabilitiesNoncurrent" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="noa_NumberOfProvincialIncomeTaxingJurisdictions" name="NumberOfProvincialIncomeTaxingJurisdictions" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_NumberofAdditionalProvincialIncomeTaxingJurisdictionsPriortoDisposal" name="NumberofAdditionalProvincialIncomeTaxingJurisdictionsPriortoDisposal" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_OfficeAndComputerEquipmentMember" name="OfficeAndComputerEquipmentMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_OperatingLeasesFutureMinimumPaymentsDueInFiveYearsAndThereafter" name="OperatingLeasesFutureMinimumPaymentsDueInFiveYearsAndThereafter" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="noa_OtherLongTermLiabilitiesLineItems" name="OtherLongTermLiabilitiesLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_PaymentsforRepurchaseofCommonStockUnitSettlement" name="PaymentsforRepurchaseofCommonStockUnitSettlement" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="noa_PaymentsofLeaseInducements" name="PaymentsofLeaseInducements" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="noa_PaymentstoSettleSharebasedPaymentAward" name="PaymentstoSettleSharebasedPaymentAward" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_PerformanceRestrictedShareUnitPlanMember" name="PerformanceRestrictedShareUnitPlanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_PerformanceRestrictedShareUnitsMember" name="PerformanceRestrictedShareUnitsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_PilingMember" name="PilingMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_PrepaidExpensesAndDepositsDisclosureTextBlock" name="PrepaidExpensesAndDepositsDisclosureTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_PrepaidInsuranceandDeposits" name="PrepaidInsuranceandDeposits" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="noa_PrepaidRentNoncurrent" name="PrepaidRentNoncurrent" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="noa_ProceedsFromDisposalOfPropertyHeldForSale" name="ProceedsFromDisposalOfPropertyHeldForSale" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="noa_ProjectCost" name="ProjectCost" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="noa_ReclassificationfromInventorytoPlantandEquipment" name="ReclassificationfromInventorytoPlantandEquipment" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_RestrictedShareUnitPlanMember" name="RestrictedShareUnitPlanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_RevenueRecognitionContractsTable" name="RevenueRecognitionContractsTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_RevenuesContractClaims" name="RevenuesContractClaims" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="noa_SaleLeasebackTransactionDeferredGainAdditions" name="SaleLeasebackTransactionDeferredGainAdditions" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="noa_SaleLeasebackTransactionDeferredGainCurrent" name="SaleLeasebackTransactionDeferredGainCurrent" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="noa_ScheduleOfContractClaimsRevenueTableTextBlock" name="ScheduleOfContractClaimsRevenueTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_ScheduleOfDeferredFinanceCostsTableTextBlock" name="ScheduleOfDeferredFinanceCostsTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_ScheduleOfInterestExpenseLineItems" name="ScheduleOfInterestExpenseLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_ScheduleOfInterestExpenseTable" name="ScheduleOfInterestExpenseTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_ScheduleOfInterestExpenseTableTextBlock" name="ScheduleOfInterestExpenseTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_ScheduleOfLeaseIncentivesTableTextBlock" name="ScheduleOfLeaseIncentivesTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_ScheduleOfOtherLiabilitiesTableTextBlock" name="ScheduleOfOtherLiabilitiesTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_ScheduleOfOtherLongTermLiabilitiesTable" name="ScheduleOfOtherLongTermLiabilitiesTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_ScheduleOfSubsidiariesTableTextBlock" name="ScheduleOfSubsidiariesTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_ScheduleOfTradeReceivablesAgingTableTextBlock" name="ScheduleOfTradeReceivablesAgingTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_ScheduleofDeferredLeaseInducementsAssetsRollforwardTableTextBlock" name="ScheduleofDeferredLeaseInducementsAssetsRollforwardTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_SeniorExecutiveStockOptionPlanMember" name="SeniorExecutiveStockOptionPlanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_Series1DebenturesMember" name="Series1DebenturesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriodSubsequentToYearOfGrant" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriodSubsequentToYearOfGrant" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingFairValuePerShare" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingFairValuePerShare" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="instant" />
  <xsd:element id="noa_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsPercentageOfNonOfficerDirectorCompensationPaidInFormOfDeferredStockUnits" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsPercentageOfNonOfficerDirectorCompensationPaidInFormOfDeferredStockUnits" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfTradingDaysUsedToCalculateWeightedAverageTradingPriceOfCommonStock" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfTradingDaysUsedToCalculateWeightedAverageTradingPriceOfCommonStock" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAnnualVestingPercentage" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAnnualVestingPercentage" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsNumberOfCommonSharesAwardedPerEachOptionExercised" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsNumberOfCommonSharesAwardedPerEachOptionExercised" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_ShareBasedCompensationArrangementByShareBasedPaymentAwardPeriodForRecognition" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardPeriodForRecognition" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePrice" name="ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePrice" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_ShareOptionPlanMember" name="ShareOptionPlanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsDividendEquivalentsGranted" name="SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsDividendEquivalentsGranted" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsDividendEquivalentsGrantedWeightedAverageGrantDateFairValue" name="SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsDividendEquivalentsGrantedWeightedAverageGrantDateFairValue" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsModifiedinPeriod" name="SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsModifiedinPeriod" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsModifiedinPeriodWeightedAverageGrantDateFairValue" name="SharebasedCompensationArrangementbySharebasedPaymentAwardEquityInstrumentsOtherthanOptionsModifiedinPeriodWeightedAverageGrantDateFairValue" nillable="true" substitutionGroup="xbrli:item" type="num:perShareItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_SharebasedCompensationArrangementbySharebasedPaymentAwardPlanModificationNumberofShares" name="SharebasedCompensationArrangementbySharebasedPaymentAwardPlanModificationNumberofShares" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_SixPointFiveSixMember" name="SixPointFiveSixMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_SixteenPointFortySixMember" name="SixteenPointFortySixMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_StockIssuedDuringPeriodSharesTreasuryStockReissuedtoSatisfySharedbasedCompensationObligations" name="StockIssuedDuringPeriodSharesTreasuryStockReissuedtoSatisfySharedbasedCompensationObligations" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_StockPurchaseProgramMember" name="StockPurchaseProgramMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_StockRepurchaseProgramCommonVotingSharesPurchasedPercentage" name="StockRepurchaseProgramCommonVotingSharesPurchasedPercentage" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_StockRepurchaseProgramNumberofSharestobePurchasedandRetired" name="StockRepurchaseProgramNumberofSharestobePurchasedandRetired" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_TenPointTwentyOneMember" name="TenPointTwentyOneMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_TermAndRevolvingCreditFacilitiesMember" name="TermAndRevolvingCreditFacilitiesMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_TermOfContract" name="TermOfContract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_ThirteenPointFiftyMember" name="ThirteenPointFiftyMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_ThreePointSixtyNineMember" name="ThreePointSixtyNineMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="noa_TradeAndOtherAccountsReceivableAllowanceForDoubtfulAccountsPolicyTableTextBlock" name="TradeAndOtherAccountsReceivableAllowanceForDoubtfulAccountsPolicyTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_TrancheAMember" name="TrancheAMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_TrancheBMember" name="TrancheBMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_TwoPointSeventyFiveMember" name="TwoPointSeventyFiveMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_TwoPointSeventyNineMember" name="TwoPointSeventyNineMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_TwoThousandThirtyFiveMember" name="TwoThousandThirtyFiveMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_TwoThousandThirtyFourMember" name="TwoThousandThirtyFourMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_TwoThousandThirtyMember" name="TwoThousandThirtyMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_TwoThousandThirtyOneMember" name="TwoThousandThirtyOneMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_TwoThousandThirtyThreeMember" name="TwoThousandThirtyThreeMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_TwoThousandThirtyTwoMember" name="TwoThousandThirtyTwoMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_TwoThousandTwentyEightMember" name="TwoThousandTwentyEightMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_TwoThousandTwentyNineMember" name="TwoThousandTwentyNineMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_TwoThousandTwentySevenMember" name="TwoThousandTwentySevenMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_TwoThousandTwentySixMember" name="TwoThousandTwentySixMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_YearOfExpirationAxis" name="YearOfExpirationAxis" nillable="true" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="noa_YearOfExpirationDomain" name="YearOfExpirationDomain" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
</xsd:schema>
