<?xml version="1.0" encoding="us-ascii"?><InstanceReport xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"><Version>2.2.0.25</Version><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios><ReportLongName>0216 - Disclosure - Commitments and Contingencies</ReportLongName><DisplayLabelColumn>true</DisplayLabelColumn><ShowElementNames>false</ShowElementNames><RoundingOption /><HasEmbeddedReports>false</HasEmbeddedReports><Columns><Column><Id>1</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><LabelColumn>false</LabelColumn><CurrencyCode>USD</CurrencyCode><FootnoteIndexer /><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios><MCU><KeyName>1/1/2010 - 12/31/2010
USD ($)

USD ($) / shares
</KeyName><CurrencySymbol>$</CurrencySymbol><contextRef><ContextID>Jan-01-2010_Dec-31-2010</ContextID><EntitySchema>http://www.sec.gov/CIK</EntitySchema><EntityValue>0000105634</EntityValue><PeriodDisplayName /><PeriodType>duration</PeriodType><PeriodStartDate>2010-01-01T00:00:00</PeriodStartDate><PeriodEndDate>2010-12-31T00:00:00</PeriodEndDate><Segments /><Scenarios /></contextRef><UPS><UnitProperty><UnitID>USD</UnitID><UnitType>Standard</UnitType><StandardMeasure><MeasureSchema>http://www.xbrl.org/2003/iso4217</MeasureSchema><MeasureValue>USD</MeasureValue><MeasureNamespace>iso4217</MeasureNamespace></StandardMeasure><Scale>0</Scale></UnitProperty><UnitProperty><UnitID>USDEPS</UnitID><UnitType>Divide</UnitType><NumeratorMeasure><MeasureSchema>http://www.xbrl.org/2003/iso4217</MeasureSchema><MeasureValue>USD</MeasureValue><MeasureNamespace>iso4217</MeasureNamespace></NumeratorMeasure><DenominatorMeasure><MeasureSchema>http://www.xbrl.org/2003/instance</MeasureSchema><MeasureValue>shares</MeasureValue><MeasureNamespace>xbrli</MeasureNamespace></DenominatorMeasure><Scale>0</Scale></UnitProperty></UPS><CurrencyCode>USD</CurrencyCode><OriginalCurrencyCode>USD</OriginalCurrencyCode></MCU><CurrencySymbol>$</CurrencySymbol><Labels><Label Id="1" Label="12 Months Ended" /><Label Id="2" Label="Dec. 31, 2010" /></Labels></Column></Columns><Rows><Row><Id>2</Id><IsAbstractGroupTitle>true</IsAbstractGroupTitle><Level>0</Level><ElementName>eme_CommitmentsAndContingenciesAbstract</ElementName><ElementPrefix>eme</ElementPrefix><IsBaseElement>false</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><ShortDefinition>Commitments And Contingencies.</ShortDefinition><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsSubReportEnd>false</IsSubReportEnd><IsCalendarTitle>false</IsCalendarTitle><IsTuple>false</IsTuple><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><PreferredLabelRole /><FootnoteIndexer /><Cells><Cell><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText /><NonNumericTextHeader /><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios></Cell></Cells><OriginalInstanceReportColumns /><Unit>Other</Unit><ElementDataType>xbrli:stringItemType</ElementDataType><SimpleDataType>string</SimpleDataType><ElementDefenition>Commitments And Contingencies.</ElementDefenition><IsTotalLabel>false</IsTotalLabel><IsEPS>false</IsEPS><Label>Commitments and Contingencies [Abstract]</Label></Row><Row><Id>3</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><Level>0</Level><ElementName>us-gaap_CommitmentsAndContingenciesDisclosureTextBlock</ElementName><ElementPrefix>us-gaap</ElementPrefix><IsBaseElement>true</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><ShortDefinition>No definition available.</ShortDefinition><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsSubReportEnd>false</IsSubReportEnd><IsCalendarTitle>false</IsCalendarTitle><IsTuple>false</IsTuple><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><PreferredLabelRole>verboselabel</PreferredLabelRole><FootnoteIndexer /><Cells><Cell><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText>&lt;!--DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd" --&gt;
   &lt;!-- Begin Block Tagged Note 16 - us-gaap:CommitmentsAndContingenciesDisclosureTextBlock--&gt;
   &lt;div style="margin-left: 0%"&gt;
   &lt;div style="margin-top: 18pt; font-size: 1pt"&gt;&amp;#160;
   &lt;/div&gt;
   &lt;table width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: transparent; text-align: left"&gt;
   &lt;tr&gt;
       &lt;td width="9%"&gt;&lt;/td&gt;
       &lt;td width="91%"&gt;&lt;/td&gt;
   &lt;/tr&gt;
   &lt;tr valign="top"&gt;
       &lt;td&gt;
       &lt;b&gt;&lt;font style="font-family: 'Times New Roman', Times"&gt;NOTE&amp;#160;16&amp;#8212;&lt;/font&gt;&lt;/b&gt;
   &lt;/td&gt;
       &lt;td&gt;
       &lt;b&gt;&lt;font style="font-family: 'Times New Roman', Times"&gt;COMMITMENTS
       AND CONTINGENCIES&lt;/font&gt;&lt;/b&gt;
   &lt;/td&gt;
   &lt;/tr&gt;
   &lt;/table&gt;
   &lt;div style="margin-top: 18pt; font-size: 1pt"&gt;&amp;#160;
   &lt;/div&gt;
   &lt;div align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: transparent"&gt;
       &lt;i&gt;&lt;font style="font-family: 'Times New Roman', Times"&gt;Commitments&lt;/font&gt;&lt;/i&gt;
   &lt;/div&gt;
   &lt;div style="margin-top: 6pt; font-size: 1pt"&gt;&amp;#160;
   &lt;/div&gt;
   &lt;div align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 3%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: transparent"&gt;
       We lease land, buildings and equipment under various leases. The
       leases frequently include renewal options and escalation clauses
       and require us to pay for utilities, taxes, insurance and
       maintenance expenses.
   &lt;/div&gt;
   &lt;div style="margin-top: 6pt; font-size: 1pt"&gt;&amp;#160;
   &lt;/div&gt;
   &lt;div align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 3%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: transparent"&gt;
       Future minimum payments, by year and in the aggregate, under
       capital leases, non-cancelable operating leases and related
       subleases with initial or remaining terms of one or more years
       at December&amp;#160;31, 2010, were as follows (in thousands):
   &lt;/div&gt;
   &lt;div style="margin-top: 6pt; font-size: 1pt"&gt;&amp;#160;
   &lt;/div&gt;
   &lt;table border="0" width="100%" align="center" cellpadding="0" cellspacing="0" style="font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: transparent; text-align: left"&gt;
   &lt;!-- Table Width Row BEGIN --&gt;
   &lt;tr style="font-size: 1pt" valign="bottom"&gt;
       &lt;td width="74%"&gt;&amp;#160;&lt;/td&gt;&lt;!-- colindex=01 type=maindata --&gt;
       &lt;td width="2%"&gt;&amp;#160;&lt;/td&gt;&lt;!-- colindex=02 type=gutter --&gt;
       &lt;td width="1%" align="right"&gt;&amp;#160;&lt;/td&gt;&lt;!-- colindex=02 type=lead --&gt;
       &lt;td width="3%" align="right"&gt;&amp;#160;&lt;/td&gt;&lt;!-- colindex=02 type=body --&gt;
       &lt;td width="1%" align="left"&gt;&amp;#160;&lt;/td&gt;&lt;!-- colindex=02 type=hang1 --&gt;
       &lt;td width="3%"&gt;&amp;#160;&lt;/td&gt;&lt;!-- colindex=03 type=gutter --&gt;
       &lt;td width="1%" align="right"&gt;&amp;#160;&lt;/td&gt;&lt;!-- colindex=03 type=lead --&gt;
       &lt;td width="5%" align="right"&gt;&amp;#160;&lt;/td&gt;&lt;!-- colindex=03 type=body --&gt;
       &lt;td width="1%" align="left"&gt;&amp;#160;&lt;/td&gt;&lt;!-- colindex=03 type=hang1 --&gt;
       &lt;td width="3%"&gt;&amp;#160;&lt;/td&gt;&lt;!-- colindex=04 type=gutter --&gt;
       &lt;td width="1%" align="right"&gt;&amp;#160;&lt;/td&gt;&lt;!-- colindex=04 type=lead --&gt;
       &lt;td width="4%" align="right"&gt;&amp;#160;&lt;/td&gt;&lt;!-- colindex=04 type=body --&gt;
       &lt;td width="1%" align="left"&gt;&amp;#160;&lt;/td&gt;&lt;!-- colindex=04 type=hang1 --&gt;
   &lt;/tr&gt;
   &lt;!-- Table Width Row END --&gt;
   &lt;!-- TableOutputHead --&gt;
   &lt;tr style="font-size: 8pt" valign="bottom" align="center"&gt;
   &lt;td nowrap="nowrap" align="center" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td colspan="2" nowrap="nowrap" align="center" valign="bottom"&gt;
       &lt;b&gt;Capital&lt;br /&gt;
       &lt;/b&gt;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td colspan="2" nowrap="nowrap" align="center" valign="bottom"&gt;
       &lt;b&gt;Operating&lt;br /&gt;
       &lt;/b&gt;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td colspan="2" nowrap="nowrap" align="center" valign="bottom"&gt;
       &lt;b&gt;Sublease&lt;br /&gt;
       &lt;/b&gt;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;/tr&gt;
   &lt;tr style="font-size: 8pt" valign="bottom" align="center"&gt;
   &lt;td nowrap="nowrap" align="center" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td colspan="2" nowrap="nowrap" align="center" valign="bottom" style="border-bottom: 1px solid #000000"&gt;
       &lt;b&gt;Leases&lt;/b&gt;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td colspan="2" nowrap="nowrap" align="center" valign="bottom" style="border-bottom: 1px solid #000000"&gt;
       &lt;b&gt;Leases&lt;/b&gt;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td colspan="2" nowrap="nowrap" align="center" valign="bottom" style="border-bottom: 1px solid #000000"&gt;
       &lt;b&gt;Income&lt;/b&gt;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;/tr&gt;
   &lt;tr style="line-height: 3pt; font-size: 1pt"&gt;
   &lt;td&gt;&amp;#160;
   &lt;/td&gt;
   &lt;/tr&gt;
   &lt;!-- TableOutputBody --&gt;
   &lt;tr valign="bottom" style="background: #cceeff"&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &lt;div style="text-indent: -10pt; margin-left: 10pt"&gt;
       2011
   &lt;/div&gt;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
       $
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
       597
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
       $
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
       51,560
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
       $
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
       1,007
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;/tr&gt;
   &lt;tr valign="bottom"&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &lt;div style="text-indent: -10pt; margin-left: 10pt"&gt;
       2012
   &lt;/div&gt;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
       453
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
       38,729
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
       1,011
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;/tr&gt;
   &lt;tr valign="bottom" style="background: #cceeff"&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &lt;div style="text-indent: -10pt; margin-left: 10pt"&gt;
       2013
   &lt;/div&gt;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
       443
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
       29,079
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
       963
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;/tr&gt;
   &lt;tr valign="bottom"&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &lt;div style="text-indent: -10pt; margin-left: 10pt"&gt;
       2014
   &lt;/div&gt;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
       433
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
       22,816
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
       676
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;/tr&gt;
   &lt;tr valign="bottom" style="background: #cceeff"&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &lt;div style="text-indent: -10pt; margin-left: 10pt"&gt;
       2015
   &lt;/div&gt;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
       &amp;#8212;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
       18,881
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
       553
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;/tr&gt;
   &lt;tr valign="bottom"&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &lt;div style="text-indent: -10pt; margin-left: 10pt"&gt;
       Thereafter
   &lt;/div&gt;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
       &amp;#8212;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
       30,832
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
       43
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;/tr&gt;
   &lt;tr valign="bottom" style="font-size: 1pt"&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td style="border-top: 1px solid #000000"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td style="border-top: 1px solid #000000"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td style="border-top: 1px solid #000000"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td style="border-top: 1px solid #000000"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td style="border-top: 1px solid #000000"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td style="border-top: 1px solid #000000"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;/tr&gt;
   &lt;tr valign="bottom" style="background: #cceeff"&gt;
   &lt;td align="left" valign="bottom"&gt;
   &lt;div style="text-indent: -10pt; margin-left: 10pt"&gt;
       Total minimum lease payment
   &lt;/div&gt;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
       1,926
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
       $
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
       191,897
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
       $
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
       4,253
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;/tr&gt;
   &lt;tr valign="bottom" style="font-size: 1pt"&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td style="border-top: 3px double #000000"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td style="border-top: 3px double #000000"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td style="border-top: 3px double #000000"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td style="border-top: 3px double #000000"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;/tr&gt;
   &lt;tr valign="bottom"&gt;
   &lt;td align="left" valign="bottom"&gt;
   &lt;div style="text-indent: -10pt; margin-left: 10pt"&gt;
       Amounts representing interest
   &lt;/div&gt;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
       (277
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
       )
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;/tr&gt;
   &lt;tr valign="bottom" style="font-size: 1pt"&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td style="border-top: 1px solid #000000"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td style="border-top: 1px solid #000000"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;/tr&gt;
   &lt;tr valign="bottom" style="background: #cceeff"&gt;
   &lt;td align="left" valign="bottom"&gt;
   &lt;div style="text-indent: -10pt; margin-left: 10pt"&gt;
       Present value of net minimum lease payments
   &lt;/div&gt;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
       $
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
       1,649
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="right" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td nowrap="nowrap" align="left" valign="bottom"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;/tr&gt;
   &lt;tr valign="bottom" style="font-size: 1pt"&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td style="border-top: 3px double #000000"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td style="border-top: 3px double #000000"&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;td&gt;
   &amp;#160;
   &lt;/td&gt;
   &lt;/tr&gt;
   &lt;/table&gt;
   &lt;div align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 0%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: transparent"&gt;
   &lt;/div&gt;
   &lt;div style="margin-top: 6pt; font-size: 1pt"&gt;&amp;#160;
   &lt;/div&gt;
   &lt;div align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 3%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: transparent"&gt;
       Rent expense for operating leases and other rental items,
       including short-term equipment rentals charged to cost of sales
       for our construction contracts, for the years ended
       December&amp;#160;31, 2010, 2009 and 2008 was $90.0&amp;#160;million,
       $97.4&amp;#160;million and $108.2&amp;#160;million, respectively. Rent
       expense for the years ended December&amp;#160;31, 2010, 2009 and
       2008 was reported net of sublease rental income of
       $0.9&amp;#160;million, $0.7&amp;#160;million and $0.6&amp;#160;million,
       respectively.
   &lt;/div&gt;
   &lt;div style="margin-top: 18pt; font-size: 1pt"&gt;&amp;#160;
   &lt;/div&gt;
   &lt;div align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: transparent"&gt;
       &lt;i&gt;&lt;font style="font-family: 'Times New Roman', Times"&gt;Contractual
       Guarantees&lt;/font&gt;&lt;/i&gt;
   &lt;/div&gt;
   &lt;div style="margin-top: 6pt; font-size: 1pt"&gt;&amp;#160;
   &lt;/div&gt;
   &lt;div align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 3%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: transparent"&gt;
       We have agreements with our executive officers and certain other
       key management personnel providing for severance benefits for
       such employees upon termination of their employment under
       certain circumstances.
   &lt;/div&gt;
   &lt;div style="margin-top: 6pt; font-size: 1pt"&gt;&amp;#160;
   &lt;/div&gt;
   &lt;div align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 3%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: transparent"&gt;
       We are contingently liable to sureties in respect of performance
       and payment bonds issued by sureties, usually at the request of
       customers in connection with construction projects, which secure
       our payment and performance obligations under contracts for such
       projects. In addition, at the request of labor unions
       representing certain of our employees, bonds are sometimes
       provided to secure obligations for wages and benefits payable to
       or for such employees. Our bonding requirements typically
       increase as the amount of public sector work increases. As of
       December&amp;#160;31, 2010, based on our
       &lt;font style="white-space: nowrap"&gt;percentage-of-completion&lt;/font&gt;
       of our projects covered by surety bonds, our aggregate estimated
       exposure, had there been defaults on all our then existing
       contractual obligations, was approximately $1.4&amp;#160;billion.
       The surety bonds are issued by surety companies in return for
       premiums, which vary depending on the size and type of bond. We
       have agreed to indemnify the sureties for amounts, if any, paid
       by them in respect of bonds issued on our behalf.
   &lt;/div&gt;
   &lt;div style="margin-top: 6pt; font-size: 1pt"&gt;&amp;#160;
   &lt;/div&gt;
   &lt;div align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 3%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: transparent"&gt;
       We are subject to regulation with respect to the handling of
       certain materials used in construction, which are classified as
       hazardous or toxic by federal, state and local agencies. Our
       practice is to avoid participation in projects principally
       involving the remediation or removal of such materials. However,
       when remediation is required as part of our contract
       performance, we believe we comply with all applicable
       regulations governing the discharge of material into the
       environment or otherwise relating to the protection of the
       environment.
   &lt;/div&gt;
   &lt;div style="margin-top: 6pt; font-size: 1pt"&gt;&amp;#160;
   &lt;/div&gt;
   &lt;div align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 3%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: transparent"&gt;
       At December&amp;#160;31, 2010, we employed over 24,000&amp;#160;people,
       approximately 65% of whom are represented by various unions
       pursuant to more than 400 collective bargaining agreements
       between our individual subsidiaries and local unions. We believe
       that our employee relations are generally good. Only two of
       these collective bargaining agreements are national or regional
       in scope.
   &lt;/div&gt;
   &lt;!-- XBRL Pagebreak Begin --&gt;
   &lt;/div&gt;
   &lt;!-- END PAGE WIDTH --&gt;
   &lt;!-- PAGEBREAK --&gt;
   &lt;div style="margin-left: 0%"&gt;
   &lt;!-- BEGIN PAGE WIDTH --&gt;
   &lt;div align="center" style="margin-left: 0%; margin-right: 0%; font-size: 12pt; font-family: Arial, Helvetica; color: #000000; background: transparent"&gt;
   &lt;b&gt;
   &lt;font style="font-family: 'Times New Roman', Times"&gt;
   &lt;font style="font-size: 10pt"&gt;
   &lt;/font&gt;
   &lt;/font&gt;
   &lt;/b&gt;
   &lt;/div&gt;
   &lt;div style="margin-top: 0pt; font-size: 1pt"&gt;
   &lt;/div&gt;
   &lt;div style="margin-top: 0pt; font-size: 1pt"&gt;
   &lt;/div&gt;
   &lt;div align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: transparent"&gt;
   &lt;/div&gt;
   &lt;table width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: transparent"&gt;
   &lt;tr&gt;
   &lt;td width="10%"&gt;&lt;/td&gt;
   &lt;td width="90%"&gt;&lt;/td&gt;
   &lt;/tr&gt;
   &lt;tr valign="top"&gt;
   &lt;td&gt;
   &lt;b&gt;
   &lt;font style="font-family: 'Times New Roman', Times"&gt;
   &lt;/font&gt;
   &lt;/b&gt;
   &lt;/td&gt;
   &lt;td&gt;
   &lt;b&gt;
   &lt;font style="font-family: 'Times New Roman', Times"&gt;
   &lt;/font&gt;
   &lt;/b&gt;
   &lt;/td&gt;
   &lt;/tr&gt;
   &lt;/table&gt;
   &lt;!-- XBRL Pagebreak End --&gt;
   &lt;div style="margin-top: 6pt; font-size: 1pt"&gt;&amp;#160;
   &lt;/div&gt;
   &lt;div align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 3%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: transparent"&gt;
       Restructuring expenses, primarily relating to employee severance
       obligations and leased facilities, were $4.3&amp;#160;million,
       $6.0&amp;#160;million and $1.8&amp;#160;million for 2010, 2009 and 2008,
       respectively. The 2010 restructuring expenses were primarily
       attributable to our Canadian operations and our United States
       electrical construction and facilities services segment. The
       2009 restructuring expenses were primarily related to our
       Canadian and UK operations, while the 2008 restructuring
       expenses were primarily related to our UK operations. As of
       December&amp;#160;31, 2010, 2009 and 2008, the balance of our
       severance obligations was $1.0&amp;#160;million, $1.7&amp;#160;million
       and $0.5&amp;#160;million, respectively. The severance obligations
       outstanding as of December&amp;#160;31, 2009 and 2008 were paid
       during 2010 and 2009, respectively. The severance obligations
       outstanding as of December&amp;#160;31, 2010 will be paid in 2011.
   &lt;/div&gt;
   &lt;div style="margin-top: 18pt; font-size: 1pt"&gt;&amp;#160;
   &lt;/div&gt;
   &lt;div align="left" style="margin-left: 0%; margin-right: 0%; font-size: 10pt; font-family: Arial, Helvetica; color: #000000; background: transparent"&gt;
       &lt;i&gt;&lt;font style="font-family: 'Times New Roman', Times"&gt;Legal
       Matters&lt;/font&gt;&lt;/i&gt;
   &lt;/div&gt;
   &lt;div style="margin-top: 6pt; font-size: 1pt"&gt;&amp;#160;
   &lt;/div&gt;
   &lt;div align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 3%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: transparent"&gt;
       On March&amp;#160;14, 2003, John Mowlem Construction plc
       (&amp;#8220;Mowlem&amp;#8221;) presented a claim in arbitration against
       our United Kingdom subsidiary, EMCOR Group (UK) plc (formerly
       named EMCOR Drake&amp;#160;&amp;#038; Scull Group plc)
       (&amp;#8220;D&amp;#038;S&amp;#8221;), in connection with a subcontract
       D&amp;#038;S entered into with Mowlem with respect to a project for
       the United&amp;#160;Kingdom Ministry of Defence at Abbey Wood in
       Bristol, U.K. Mowlem seeks damages arising out of alleged
       defects in the D&amp;#038;S design and construction of the
       electrical and mechanical engineering services for the project.
       Mowlem&amp;#8217;s claim is for 38.5&amp;#160;million British pounds
       sterling (approximately $60.0&amp;#160;million), which includes
       costs allegedly incurred by Mowlem in connection with
       rectification of the alleged defects, overhead, legal fees,
       delay and disruption costs related to such defects, and interest
       on such amounts. The claim also includes amounts in respect of
       liabilities that Mowlem accepted in connection with a settlement
       agreement it entered into with the Ministry of Defence and which
       it claims are attributable to D&amp;#038;S. D&amp;#038;S believes it has
       good and meritorious defenses to the Mowlem claim. D&amp;#038;S has
       denied liability and has asserted a counterclaim for
       approximately 11.6&amp;#160;million British pounds sterling
       (approximately $18.1&amp;#160;million) for certain design, labor and
       delay and disruption costs incurred by D&amp;#038;S in connection
       with its subcontract with Mowlem for work performed through 1996.
   &lt;/div&gt;
   &lt;div style="margin-top: 6pt; font-size: 1pt"&gt;&amp;#160;
   &lt;/div&gt;
   &lt;div align="left" style="margin-left: 0%; margin-right: 0%; text-indent: 3%; font-size: 10pt; font-family: 'Times New Roman', Times; color: #000000; background: transparent"&gt;
       We are involved in other proceedings in which damages and claims
       have been asserted against us. We believe that we have a number
       of valid defenses to such proceedings and claims and intend to
       vigorously defend ourselves. We do not believe that any such
       matters will have a materially adverse effect on our financial
       position, results of operations or liquidity.
   &lt;/div&gt;
   &lt;/div&gt;
</NonNumbericText><NonNumericTextHeader>&lt;!--DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd" --&gt;
   &lt;!-- Begin Block Tagged Note</NonNumericTextHeader><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios></Cell></Cells><OriginalInstanceReportColumns /><Unit>Other</Unit><ElementDataType>us-types:textBlockItemType</ElementDataType><SimpleDataType>string</SimpleDataType><ElementDefenition>Includes disclosure of commitments and contingencies. This element may be used as a single block of text to encapsulate the entire disclosure including data and tables.</ElementDefenition><ElementReferences>Reference 1: http://www.xbrl.org/2003/role/presentationRef
 -Publisher FASB
 -Name FASB Interpretation (FIN)
 -Number 14
 -Paragraph 3

Reference 2: http://www.xbrl.org/2003/role/presentationRef
 -Publisher FASB
 -Name Statement of Financial Accounting Standard (FAS)
 -Number 5
 -Paragraph 9, 10, 11, 12

</ElementReferences><IsTotalLabel>false</IsTotalLabel><IsEPS>false</IsEPS><Label>COMMITMENTS AND CONTINGENCIES</Label></Row></Rows><Footnotes /><NumberOfCols>1</NumberOfCols><NumberOfRows>2</NumberOfRows><ReportName>Commitments and Contingencies</ReportName><MonetaryRoundingLevel>UnKnown</MonetaryRoundingLevel><SharesRoundingLevel>UnKnown</SharesRoundingLevel><PerShareRoundingLevel>UnKnown</PerShareRoundingLevel><ExchangeRateRoundingLevel>UnKnown</ExchangeRateRoundingLevel><HasCustomUnits>false</HasCustomUnits><SharesShouldBeRounded>true</SharesShouldBeRounded></InstanceReport>
