UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
 Washington, D.C. 20549
 
 FORM 11-K
  þ
    
    Annual Report Pursuant to Section 15(d) of the Securities Exchange Act of 1934
 For the fiscal year ended December 31, 2010
 OR
 o
    
    Transition Report Pursuant to Section 15(d) of the Securities Exchange Act of 1934
 Commission file number: 0-49807
 A.
    
    Full title of the plan and the address of the plan, if different from that of
the issuer named below:
 WASHINGTON GAS LIGHT COMPANY
CAPITAL APPRECIATION PLAN
 B.
    
    Name of issuer of the securities held pursuant to the plan and the address of its
principal executive office:




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Washington Gas Light Company Capital Appreciation Plan
For the Fiscal Year Ended December 31, 2010
 Table of Contents
  Report of Independent Registered Public Accounting Firm
    
    
    1Statements of Net Assets Available for Benefits
    
    
    2Statements of Changes in Net Assets Available for Benefits
    
    
    3Notes to Financial Statements
    
    
    4Form 5500, Schedule G, Part I  Schedule of Loans on Fixed
Income Obligations in Default or Classified as uncollectible
    
    
    15Form 5500, Schedule H, Line 4i  Schedule of Assets (Held at End of
Year) as of December 31, 2010
    
    
    16Signatures
    
    
    17Exhibit 23  Consent of Independent Registered Public Accounting Firm
    
    
    18




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REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM
 
      
 -1-




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Washington Gas Light Company Capital Appreciation Plan
Statements of Net Assets Available for Benefits
 2010
    
    
    2009AssetsInvestments, at fair value:Registered investment companies
    
    $
    27,375,858
    
    
    $
    25,249,875Common/collective trust funds
    
    
    10,875,877
    
    
    
    9,114,272Stable Value Fund
    
    
    16,246,930
    
    
    
    15,655,076WGL Holdings, Inc. Common Stock Fund
    
    
    12,535,440
    
    
    
    12,059,809Total Investments
    
    
    67,034,105
    
    
    
    62,079,032Receivables:Employee contribution
    
    
    83,737
    
    
    
    56,187Employer contribution
    
    
    28,741
    
    
    
    18,108Notes receivable from participants
    
    
    3,185,382
    
    
    
    3,009,174Total Receivables
    
    
    3,297,860
    
    
    
    3,083,469Net Assets Reflecting Investments at Fair Value
    
    
    70,331,965
    
    
    
    65,162,501Adjustment from fair value to contract value for fully
benefit-responsive investment contracts
    
    
    (349,738
    )
    
    
    (31,248
    )Net Assets Available for Benefits
    
    $
    69,982,227
    
    
    $
    65,131,253
 The accompanying notes are an integral part of these statements.
 -2-




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Washington Gas Light Company Capital Appreciation Plan
Statements of Changes in Net Assets Available for Benefits
 2010
    
    
    2009Investment Income:Net appreciation in fair value of investments
    
    $
    5,101,673
    
    
    $
    7,330,948Net appreciation in contract value of investments
    
    
    437,538
    
    
    
    420,737Dividend and interest income
    
    
    767,260
    
    
    
    851,454Total Investment Income
    
    
    6,306,471
    
    
    
    8,603,139Interest income on notes receivable from participants
    
    
    146,208
    
    
    
    163,683Transfer out  to the Washington Gas Light Company Savings Plan
    
    
    (1,214,338
    )
    
    
    (605,289
    )Contributions:Employee
    
    
    2,669,287
    
    
    
    2,670,864Employer
    
    
    1,213,502
    
    
    
    1,191,940Total Contributions
    
    
    3,882,789
    
    
    
    3,862,804Deductions:Benefits paid
    
    
    (4,110,219
    )
    
    
    (2,995,865
    )Administrative expenses
    
    
    (159,937
    )
    
    
    (19,636
    )Total Deductions
    
    
    (4,270,156
    )
    
    
    (3,015,501
    )Net Increase in Net Assets
    
    
    4,850,974
    
    
    
    9,008,836Net Assets Available for Benefits:Beginning of Year
    
    
    65,131,253
    
    
    
    56,122,417End of Year
    
    $
    69,982,227
    
    
    $
    65,131,253
 The accompanying notes are an integral part of these statements.
 -3-




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WASHINGTON GAS LIGHT COMPANY CAPITAL APPRECIATION PLAN
 Note 1Description of the Capital Appreciation Plan
  General
   Contributions
    -4-




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WASHINGTON GAS LIGHT COMPANY CAPITAL APPRECIATION PLAN
NOTES TO FINANCIAL STATEMENTS (continued)
 Note 1Description of the Capital Appreciation Plan (continued)
    Vesting
  Participant Accounts
  Investments
  Distributions
  -5-




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WASHINGTON GAS LIGHT COMPANY CAPITAL APPRECIATION PLAN
NOTES TO FINANCIAL STATEMENTS (continued)
 Note 1Description of the Capital Appreciation Plan (continued)
  In-Service Withdrawals
  Participant Loans
  Amendment or Termination
  Note 2Significant Accounting Policies
 Basis of Accounting
  Use of Estimates
  -6-




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WASHINGTON GAS LIGHT COMPANY CAPITAL APPRECIATION PLAN
NOTES TO FINANCIAL STATEMENTS (continued)
 Note 2Significant Accounting Policies (continued)
 Investment Valuation and Income Recognition
    Reporting of Investment Contracts  (Stable Value Fund)
   Plan Accounting  Defined Contribution Pension Plans
 Distributions
  -7-




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WASHINGTON GAS LIGHT COMPANY CAPITAL APPRECIATION PLAN
NOTES TO FINANCIAL STATEMENTS (continued)
 Note 2Significant Accounting Policies (continued)
 Administrative Expenses
  Note 3Tax Status
   Note 4Plan Amendments
  -8-




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WASHINGTON GAS LIGHT COMPANY CAPITAL APPRECIATION PLAN
NOTES TO FINANCIAL STATEMENTS (continued)
 Note 5Investments
  2010
    
    2009American Funds Growth Fund of America
    
    $
    11,409,015
    
    
    $
    10,922,885Stable Value Fund a/ b/
    
    
    15,897,192
    
    
    
    15,655,076Van Kampen Growth & Income Fund
    
    
    7,012,867
    
    
    
    6,999,812WGL Holdings, Inc. Common Stock Fund
a/
    
    
    12,535,440
    
    
    
    12,059,809
 
 a/
    
    Party-in-interest (see Note 8).b/
    
    At contract value (see Note 2).  2010
    
    
    2009Net appreciation in fair value of:Registered investment companies
    
    $
    2,773,268
    
    
    $
    5,236,659Common/collective trust funds
    
    
    1,414,185
    
    
    
    1,724,258WGL Holdings, Inc. Common Stock Fund *
    
    
    914,220
    
    
    
    370,031Total
    
    $
    5,101,673
    
    
    $
    7,330,948Net appreciation in contract value of:Stable Value Fund *
    
    $
    437,538
    
    
    $
    420,737Total
    
    $
    437,538
    
    
    $
    420,737
 
 *
    
    Party-in-interest (see Note 8). -9-




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WASHINGTON GAS LIGHT COMPANY CAPITAL APPRECIATION PLAN
NOTES TO FINANCIAL STATEMENTS (continued)
 Note 6Fair Value Measurements
  
    
    Level 1  Inputs to the valuation methodology are unadjusted quoted prices for
identical assets or liabilities in active markets that the Plan has the ability to access.
    
    Level 2  Inputs to the valuation methodology include quoted prices for similar assets
or liabilities in active markets, quoted prices for identical or similar assets or
liabilities in inactive markets, inputs other than quoted prices that are observable for
the asset or liability, or inputs that are derived principally from or corroborated by
observable market
data by correlation or other means.
    
    Level 3  Inputs to the valuation methodology are unobservable and significant to the
fair value measurement.
 Financial Services  Investment Companies
 -10-




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WASHINGTON GAS LIGHT COMPANY CAPITAL APPRECIATION PLAN
NOTES TO FINANCIAL STATEMENTS (continued)
 Note 6Fair Value Measurements (continued)
 
 December 31, 2010Level 1
    
    Level 2
    
    Level 3
    
    TotalRegistered investment companiesLarge cap funds
    
    $
    18,421,882
    
    
    $
    
    
    
    $
    
    
    
    $
    18,421,882Fixed income funds
    
    
    2,460,899
    
    
    
    
    
    
    
    
    
    
    
    2,460,899International funds
    
    
    3,842,054
    
    
    
    
    
    
    
    
    
    
    
    3,842,054Small/mid cap funds
    
    
    2,651,023
    
    
    
    
    
    
    
    
    
    
    
    2,651,023Common/collective trust fundsTarget date funds
    
    
    
    
    
    
    7,627,422
    
    
    
    
    
    
    
    7,627,422Large cap blend funds
    
    
    
    
    
    
    2,911,061
    
    
    
    
    
    
    
    2,911,061Small/mid income funds
    
    
    
    
    
    
    337,394
    
    
    
    
    
    
    
    337,394Stable Value Fund
    
    
    
    
    
    
    
    
    
    
    16,246,930
    
    
    
    16,246,930WGL Holdings, Inc. Common Stock Fund
    
    
    
    
    
    
    12,535,440
    
    
    
    
    
    
    
    12,535,440Total investments, at fair value
    
    $
    27,375,858
    
    
    $
    23,411,317
    
    
    $
    16,246,930
    
    
    $
    67,034,105
 December 31, 2009Level 1
    
    Level 2
    
    Level 3
    
    TotalRegistered investment companiesLarge cap funds
    
    $
    17,922,696
    
    
    $
    
    
    
    $
    
    
    
    $
    17,922,696Fixed income funds
    
    
    2,030,090
    
    
    
    
    
    
    
    
    
    
    
    2,030,090International funds
    
    
    3,417,278
    
    
    
    
    
    
    
    
    
    
    
    3,417,278Small/mid cap funds
    
    
    1,879,811
    
    
    
    
    
    
    
    
    
    
    
    1,879,811Common/collective trust fundsTarget date funds
    
    
    
    
    
    
    7,412,824
    
    
    
    
    
    
    
    7,412,824Large cap blend funds
    
    
    
    
    
    
    1,701,448
    
    
    
    
    
    
    
    1,701,448Stable Value Fund
    
    
    
    
    
    
    
    
    
    
    15,655,076
    
    
    
    15,655,076WGL Holdings, Inc. Common Stock Fund
    
    
    
    
    
    
    12,059,809
    
    
    
    
    
    
    
    12,059,809Total investments, at fair value
    
    $
    25,249,875
    
    
    $
    21,174,081
    
    
    $
    15,655,076
    
    
    $
    62,079,032
 -11-




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WASHINGTON GAS LIGHT COMPANY CAPITAL APPRECIATION PLAN
NOTES TO FINANCIAL STATEMENTS (continued)
 Note 6Fair Value Measurements(continued)
  Registered investment companies
 Common/collective trust fund:
 Stable Value Fund
 WGL Holdings, Inc. Common Stock Fund
 -12-




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WASHINGTON GAS LIGHT COMPANY CAPITAL APPRECIATION PLAN
NOTES TO FINANCIAL STATEMENTS (continued)
 Note 6Fair Value Measurements(continued)
  Stable Value FundBalance as of January 1, 2009
    
    $
    Purchases, sales, issuances, and
settlements, net
    
    
    Transfer in from Level 2
    
    
    15,655,076Balance as of December 31, 2009
    
    $
    15,655,076Balance as of January 1, 2010
    
    $
    15,655,076Purchases, sales, issuances, and
settlements, net
    
    
    (167,787
    )Total gains
(realized/unrealized)
    
    
    759,641Balance as of December 31, 2010
    
    $
    16,246,930
 Fair Value Measurements and Disclosures 
Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent)
  Note 7Risks and Uncertainties
  Note 8Related-Party Transactions
  -13-




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WASHINGTON GAS LIGHT COMPANY CAPITAL APPRECIATION PLAN
NOTES TO FINANCIAL STATEMENTS (continued)
 Note 9 Recent Accounting Pronouncements
 Accounting Standards Adopted in the Current Plan Year
   Reporting Loans to
Participants by Defined Contribution Pension Plans,
 Other Newly Issued Accounting Standards
  -14-




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WASHINGTON GAS LIGHT COMPANY CAPITAL APPRECIATION PLAN
 SUPPLEMENTAL SCHEDULE
 Schedule G, Part 1  Schedule of Loans or Fixed Income
Obligations in Default or Classified as Uncollectible  As of December 31, 2010
 
 * If Party
    
    
    
    
    
    Original
    
    Amount Received Duringin
    
    
    
    
    
    amount of
    
    Reporting Year
    
    Unpaid Balance
    
    
    
    Amount Over-DueInterest
    
    Identity of Obligor
    
    loan
    
    Principal
    
    Interest
    
    at 12-31-10
    
    Loan Terms
    
    Principal
    
    InterestLoan date: 06-18-09*
    
    
    Alma Smith
    
    $
    42,986.95
    
    
    $
    0.00
    
    
    $
    0.00
    
    
    $
    42,986.95
    
    
    Maturity Date: 07/10/14

Interest Rate: 4.25% 
Uncollateralized
    
    $
    11,636.16
    
    
    $
    2,322.00Loan date: 12-19-06*
    
    
    Gary Botts
    
    $
    35,174.26
    
    
    $
    0.00
    
    
    $
    0.00
    
    
    $
    29,232.89
    
    
    Maturity Date: 01/10/12

Interest Rate: 6.24% 
Uncollateralized
    
    $
    21,000.24
    
    
    $
    3,593.16
 -15-




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WASHINGTON GAS LIGHT COMPANY CAPITAL APPRECIATION PLAN
 SUPPLEMENTAL SCHEDULE
 Schedule H, Line 4i  Schedule of Assets (Held at End of Year)  As of December 31, 2010
 
 Name of Issuer
    
    Type of Investment
    
    Current ValueAmerican Funds Growth Fund of America
    
    Registered Investment Company
    
    $
    11,409,015CRM Small/Mid Cap Value Institiutional Fund
    
    Registered Investment Company
    
    
    1,213,896MFS International Growth Fund
    
    Registered Investment Company
    
    
    1,487,483PIMCO Total Return Fund
    
    Registered Investment Company
    
    
    2,460,899Templeton Institutional Foreign Equity Fund
    
    Registered Investment Company
    
    
    2,354,571Van Kampen Growth & Income Fund
    
    Registered Investment Company
    
    
    7,012,867Wells Fargo Advantage Discovery Fund
    
    Registered Investment Company
    
    
    1,437,127JPMorgan SmartRetirement Income Fund
    
    Common/Collective Trust
    
    
    337,394JPMorgan SmartRetirement 2010 Fund
    
    Common/Collective Trust
    
    
    707,657JPMorgan SmartRetirement 2015 Fund
    
    Common/Collective Trust
    
    
    1,437,569JPMorgan SmartRetirement 2020 Fund
    
    Common/Collective Trust
    
    
    1,813,556JPMorgan SmartRetirement 2025 Fund
    
    Common/Collective Trust
    
    
    1,233,013JPMorgan SmartRetirement 2030 Fund
    
    Common/Collective Trust
    
    
    1,295,519JPMorgan SmartRetirement 2035 Fund
    
    Common/Collective Trust
    
    
    516,099JPMorgan SmartRetirement 2040 Fund
    
    Common/Collective Trust
    
    
    276,702JPMorgan SmartRetirement 2045 Fund
    
    Common/Collective Trust
    
    
    120,140JPMorgan SmartRetirement 2050 Fund
    
    Common/Collective Trust
    
    
    227,167a/
    
    SSgA S&P 500 Index Fund
    
    Common/Collective Trust
    
    
    2,911,061a/ b/
    
    Stable Value Fund
    
    Common/Collective Trust
    
    
    15,897,192a/
    
    WGL Holdings, Inc. Common Stock Fund
    
    Common Stock Fund
    
    
    12,535,440Notes
Receivable from Participants
    
    Participant loans with interest
rates ranging from 4.25% to 8.44%
    
    
    3,185,382Total
    
    
    
    $
    69,869,749
 
 a/  Denotes Party-in-Interestb/  Contract Value -16-




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Washington Gas Light Company Capital Appreciation Plan
 
 Signatures
 The Plan.
 WASHINGTON GAS LIGHT COMPANY
CAPITAL APPRECIATION PLANDate: June 29, 2011
    /s/ Vincent L. Ammann, Jr.Vincent L. Ammann, Jr. (Plan Administrator)Vice President and Chief Financial Officer
Washington Gas Light Company Date: June 29, 2011
    /s/ Luanne GutermuthLuanne Gutermuth (Plan Administrator)Vice President, Human Resources and
Organization Development
Washington Gas Light Company -17-