<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-09-30</periodOfReport>

    <issuer>
        <issuerCik>0000078128</issuerCik>
        <issuerName>AQUA AMERICA INC</issuerName>
        <issuerTradingSymbol>WTR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001194707</rptOwnerCik>
            <rptOwnerName>DEBENEDICTIS NICHOLAS</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>762 W LANCASTER AVE.</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BRYN MAWR</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>19010</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2018-09-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>544</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>36.75</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>29798.79</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The number of shares beneficially owned following the reported transaction has been updated to reflect the disposition by the reporting person of 15,343 shares in a gift transaction effected in January 2018 and reported on a voluntary Form 4 on January 11, 2018, but not reflected in the beneficial ownership on Form 4 reports filed on April 3, 2018 and July 3, 2018.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Brian Dingerdissen, attorney-in-fact for Mr. DeBenedictis</signatureName>
        <signatureDate>2018-10-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
