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                                                                     Exhibit 4.7

                              WCA WASTE CORPORATION

                                 ---------------

                           CERTIFICATE OF DESIGNATIONS
                                       OF
                SERIES A CONVERTIBLE PAY-IN-KIND PREFERRED STOCK

        (Pursuant to Section 151 of the Delaware General Corporation Law)

                                 ---------------

      WCA Waste Corporation, a Delaware corporation (the "CORPORATION"), in
accordance with the provisions of Section 103 of the Delaware General
Corporation Law (the "DGCL") does hereby certify that, in accordance with
Section 141(c) of the DGCL, the following resolution was duly adopted by the
board of directors of the Corporation as of June 12, 2006:

      RESOLVED, that the board of directors of the Corporation pursuant to
authority expressly vested in it by the provisions of the Certificate of
Incorporation of the Corporation, hereby authorizes the issuance of one series
of Preferred Stock designated as the Series A Convertible Pay-In-Kind Preferred
Stock, par value $0.01 per share, of the Corporation and hereby fixes the
designation, number of shares, powers, preferences, rights, qualifications,
limitations and restrictions thereof (in addition to any provisions set forth in
the Certificate of Incorporation of the Corporation which are applicable to the
Preferred Stock of all classes and series) as follows:

                      SERIES A CONVERTIBLE PREFERRED STOCK

      1. Designation, Amount and Par Value. The following series of preferred
stock shall be designated as the Corporation's Series A Convertible Pay-In-Kind
Preferred Stock (the "SERIES A PREFERRED STOCK"), and the number of shares so
designated shall be 750,000. Each share of Series A Preferred Stock shall have a
par value of $0.01 per share. The "STATED VALUE" for each share of Series A
Preferred Stock equals the sum of (i) $100 plus (ii) any amount added to the
Stated Value pursuant to Section 3 hereof. The Series A Preferred Stock is to be
issued only pursuant to the terms of the Purchase Agreement (as hereinafter
defined).

      2. Definitions. In addition to the terms defined elsewhere in this
Certificate of Designations the following terms have the meanings indicated:

            "ACCELERATION EVENT" means the occurrence of any one or more of the
      following events: (i) a Liquidation Event; (ii) a Bankruptcy Event; (iii)
      the Corporation shall consummate a public offering of shares of Common
      Stock pursuant to an effective registration

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      statement under the Securities Act (other than (x) a registration relating
      to a transaction covered by Form S-4 (or successor form) adopted by the
      Securities and Exchange Commission, including a transaction covered by
      Rule 145 (or successor rule) adopted by the Securities and Exchange
      Commission, (y) a registration statement solely relating to Common Stock
      held by third parties (including Common Stock to be held by or issued
      pursuant to an employee benefit or stock ownership plan) and (z) pursuant
      to the Registration Rights Agreement); (iv) (a) the average of the Closing
      Price for each day during any period of twenty (20) consecutive Trading
      Days exceeds $14.40 per share on the twentieth (20th) Trading Day of such
      period or (b) if not sooner, immediately prior to a conversion pursuant to
      Section 7(b) hereof; or (v) any other Fundamental Transaction.

            "BANKRUPTCY EVENT" means any of the following events: (a) the
      Corporation or a Subsidiary of the Corporation commences a case or other
      proceeding under any bankruptcy, reorganization, arrangement, adjustment
      of debt, relief of debtors, dissolution, insolvency or liquidation or
      similar law of any jurisdiction relating to the Corporation or any
      Subsidiary thereof; (b) there is commenced against the Corporation or any
      Subsidiary any such case or proceeding that is not dismissed within 60
      days after commencement; (c) the Corporation or any Subsidiary is
      adjudicated insolvent or bankrupt or any order of relief or other order
      approving any such case or proceeding is entered; (d) the Corporation or
      any Subsidiary suffers any appointment of any custodian or the like for it
      or any substantial part of its property that is not discharged or stayed
      within 60 days; (e) the Corporation or any Subsidiary makes a general
      assignment for the benefit of creditors; (f) the Corporation or any
      Subsidiary fails to pay, or states that it is unable to pay or is unable
      to pay, its debts generally as they become due; (g) the Corporation or any
      Subsidiary calls a meeting of its creditors with a view to arranging a
      composition, adjustment or restructuring of its debts; or (h) the
      Corporation or any Subsidiary, by any act or failure to act, expressly
      indicates its consent to, approval of or acquiescence in any of the
      foregoing or takes any corporate or other action for the purpose of
      effecting any of the foregoing.

            "BUSINESS DAY" means any day except Saturday, Sunday and any day on
      which banking institutions in New York City are authorized or required by
      law or other governmental action to close.

            "CLOSING PRICE" means, for any date, the price determined by the
      first of the following clauses that applies: (a) if the Common Shares are
      then listed or quoted on the Trading Market, the closing price per Common
      Share for such date (or the nearest preceding date) on the Trading Market
      or exchange on which the Common Shares are then listed or quoted; or (b)
      in all other cases, the fair market value of a Common Share as determined
      by an independent appraiser selected in good faith by a majority in
      interest of the purchasers.

            "COMMON STOCK" means the common stock of the Corporation, par value
      $0.01 per share, and any securities into which such common stock may
      hereafter be reclassified or exchanged or converted.

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            "CONVERSION PRICE" means $9.60 per share (as adjusted for stock
      dividends, stock splits, stock combinations or other similar events
      pursuant to Section 13 hereof occurring after the Original Issue Date).

            "EQUITY CONDITIONS" means, with respect to a specified issuance of
      Common Stock, that each of the following conditions is satisfied: (i) the
      number of authorized but unissued and otherwise unreserved shares of
      Common Stock is sufficient for such issuance; (ii) the Common Stock is
      listed or quoted (and is not suspended from trading) on the Trading Market
      and such shares of Common Stock are approved for listing upon issuance;
      (iii) no Bankruptcy Event has occurred; and (iv) the Corporation is not in
      default with respect to any material obligation hereunder or under any
      other Transaction Document.

            "EXCHANGE ACT" means the Securities Exchange Act of 1934, as
      amended.

            "FUNDAMENTAL TRANSACTION" means the occurrence of any of the
      following in one or a series of related transactions: (i) an acquisition
      after the date of the Purchase Agreement by an individual or legal entity
      or "group" (as described in Rule 13d-5(b)(1) under the Exchange Act) of
      more than 35% of the voting rights or voting equity interests in the
      Corporation; (ii) a replacement of more than one-half of the members of
      the Corporation's board of directors with members that are not approved by
      those individuals who are members of the board of directors on the date of
      the Purchase Agreement (or other Persons approved by such members to be
      directors (or their successors so appointed) or appointed pursuant to the
      terms of the Stockholder's Agreement; (iii) a merger or consolidation of
      the Corporation or any Subsidiary or a sale of all or substantially all of
      the assets of the Corporation in one or a series of related transactions,
      unless following such transaction or series of transactions, the holders
      of the Corporation's securities prior to the first such transaction
      continue to hold a majority of the voting rights or voting equity
      interests in of the surviving entity or acquirer of such assets; (iv) a
      recapitalization, reorganization or other transaction involving the
      Corporation or any Subsidiary that constitutes or results in a transfer of
      a majority of the voting rights or voting equity interests in the
      Corporation; (v) consummation of a "Rule 13e-3 transaction" as defined in
      Rule 13e-3 under the Exchange Act with respect to the Corporation; (vi)
      any tender offer or exchange offer (whether by the Corporation or another
      Person) is completed pursuant to which holders of Common Stock are
      permitted to tender or exchange their shares for other securities, cash or
      property and as a result thereof the holders of a majority of the shares
      of Common Stock prior to the offer do not hold securities representing a
      majority of the voting rights or voting equity interests in the
      Corporation; (vii) the Corporation effects any reclassification of the
      Common Stock or any compulsory share exchange pursuant to which the Common
      Stock is effectively converted into or exchanged for other securities that
      do not represent a majority of the voting rights or voting equity
      interests of the Corporation, cash or property; or (viii) the execution by
      the Corporation of an agreement directly or indirectly providing for any
      of the foregoing events; provided that none of items (i) through (viii)
      shall be deemed a Fundamental Transaction if it involves Purchaser (as
      such term is defined in the Purchase Agreement) or its Related Persons (as
      such term is defined in the Stockholder's Agreement).

                                      -3-
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            "HOLDER" means any holder of Series A Preferred Stock.

            "JUNIOR SECURITIES" means the Common Stock and all other equity or
      equity equivalent securities of the Corporation.

            "LIQUIDATION EVENT" means any liquidation, dissolution or winding up
      of the Corporation, either voluntary or involuntary.

            "ORIGINAL ISSUE DATE" means the date of the first issuance of any
      shares of Series A Preferred Stock, regardless of the number of transfers
      of any particular shares of Series A Preferred Stock and regardless of the
      number of certificates that may be issued to evidence shares of Series A
      Preferred Stock.

            "PERSON" means any individual or corporation, partnership, trust,
      incorporated or unincorporated association, joint venture, limited
      liability company, joint stock company, government (or an agency or
      subdivision thereof) or other entity of any kind.

            "POST-CONVERSION EQUITY" means as of the date of determination that
      number of shares of Common Stock that are then outstanding or would be
      outstanding upon the exercise of all rights, options, and warrants (to the
      extent then exercisable and vested) and conversion of all other securities
      (including the Series A Preferred Stock) that are convertible into shares
      of Common Stock, including (if the date of determination is on or before
      the fifth anniversary of the Original Issue Date) the number of shares of
      Common Stock into which the Series A Preferred Stock could be converted if
      an Acceleration Event had occurred immediately prior to such
      determination.

            "PURCHASE AGREEMENT" means the Preferred Stock Purchase Agreement,
      dated as of June 12, 2006, among the Corporation and the original
      purchaser of the Series A Preferred Stock, as the same may be amended or
      modified in accordance with its terms.

            "REGISTRATION RIGHTS AGREEMENT" means the Registration Rights
      Agreement, dated as of the date of the Purchase Agreement, to be entered
      into among the Corporation and the Holders upon the Closing Date.

            "RULE 144" means Rule 144 promulgated by the Securities and Exchange
      Commission pursuant to the Securities Act, as such Rule may be amended
      from time to time, or any similar rule or regulation hereafter adopted by
      the Securities and Exchange Commission having substantially the same
      effect as such Rule.

            "SECURITIES ACT" means the Securities Act of 1933, as amended.

            "STOCKHOLDER'S AGREEMENT" means the Stockholder's Agreement, dated
      as of July 27, 2006, among the Corporation and the original purchaser of
      the Series A Preferred Stock.

            "SUBSIDIARY" means any significant subsidiary of the Corporation as
      defined in Rule 1-02(w) of Regulation S-X promulgated by the Securities
      and Exchange Commission.

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            "TRADING DAY" means (a) any day on which the Common Stock is listed
      or quoted and traded on the Trading Market, or (b) if the Common Stock is
      not then listed or quoted and traded on the Trading Market, then any
      Business Day.

            "TRADING MARKET" means The Nasdaq Stock Market (the "NASDAQ") or, at
      any time the Common Stock is not listed for trading on the NASDAQ, any
      national securities exchange upon which the Common Stock is then primarily
      listed or quoted.

            "TRANSACTION DOCUMENTS" means the Purchase Agreement, the
      Registration Rights Agreement, the Stockholder's Agreement, this
      Certificate of Designations and any other documents or agreements executed
      or delivered in connection with the transactions contemplated under the
      Purchase Agreement and thereunder.

            "UNDERLYING SHARES" means the shares of Common Stock issuable upon
      conversion of the shares of Series A Preferred Stock.

      3. Dividends.

            (a) Each Holder shall be entitled to receive, and the Corporation
shall pay, cumulative dividends on the Series A Preferred Stock at the rate per
share (as a percentage of the Stated Value per share) of 5.00% per annum,
payable semi-annually in arrears commencing on December 31, 2006 and thereafter
on each June 30 and December 31, except if such date is not a Trading Day, in
which case such dividend shall be payable on the next succeeding Trading Day
(each, a "DIVIDEND PAYMENT DATE"). Dividends on the Series A Preferred Stock
shall be calculated on the basis of a 360-day year, shall accrue daily
commencing on the Original Issue Date for the applicable Series A Preferred
Stock, and shall be deemed to accrue from such date whether or not earned or
declared and whether or not there are profits, surplus or other funds of the
Corporation legally available for the payment of dividends. Dividends shall be
payable by the Corporation solely by adding the amount of deferred dividends per
share of Series A Preferred Stock to the Stated Value of that share; provided
that after the fifth anniversary of the Closing Date, the Corporation may, at
its option, pay dividends in cash. No dividend or other distribution (other than
(y) a dividend or distribution payable solely in Common Stock or (z) a cash
dividend or distribution with respect to which holders of shares of Series A
Preferred Stock receive a pro rata portion of such dividend or distribution on
an as-converted basis) shall be paid on or set apart for payment on Common Stock
or any other Junior Securities unless all accrued and unpaid dividends on the
Series A Preferred Stock (but not amounts previously added to Stated Value
pursuant to this Section 3) have been paid in accordance with this Certificate
of Designations.

            (b) Immediately prior to the occurrence of any Acceleration Event
prior to the fifth anniversary of the Original Issue Date, the Stated Value of
each share of Series A Preferred Stock shall immediately and automatically be
increased by an amount per share equal to all dividends that would otherwise be
payable on a share of Series A Preferred Stock on each Dividend Payment Date on
and after the occurrence of such Acceleration Event and prior to and including
the fifth anniversary of such Original Issue Date (the "ACCELERATION PERIOD").
The accelerated payment of dividends pursuant to this Section 3(b) shall be in
lieu of, and not in addition to, the dividends that would otherwise be payable
on each Dividend Payment Date during the Acceleration

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Period. For the purpose of clarity, and only in the event that the Corporation
has not elected to require conversion under Section 7(b), each Holder shall be
entitled to receive, and the Corporation shall pay, all dividends payable in
accordance with Section 3(a) above on each Dividend Payment Date after the fifth
anniversary of the Original Issue Date.

            (c) All accrued but unpaid dividends shall be payable upon,

                  (i) a Liquidation Event in cash;

                  (ii) a Fundamental Transaction that the Holders elect to treat
            as a Liquidation Event pursuant to Section 6(c) in cash or in other
            securities or property as specified in Section 6(c); or;

                  (iii) conversion of the Series A Preferred Stock,

                        (1) during the Acceleration Period and prior to an
                        Acceleration Event, in additional Underlying Shares as
                        provided in Section 8(a); and

                        (2) otherwise, at the option of the Company, either (A)
                        in cash or (B) in additional Underlying Shares as
                        provided in Section 8(a).

      For the purposes of this Section 3(c), accrued but unpaid dividends shall
include any amounts added to Stated Value as a result of deferred dividends or
accelerated dividends as provided in Section 3(a), provided, however, that to
avoid double counting accrued but unpaid dividends shall not be counted both for
the purposes of this Section 3(c) and in determining Stated Value.

      4. Registration of Issuance and Ownership of Series A Preferred Stock. The
Corporation shall register the issuance and ownership of shares of the Series A
Preferred Stock, upon records to be maintained by the Corporation for that
purpose (the "SERIES A PREFERRED STOCK REGISTER"), in the name of the record
Holders thereof from time to time. The Corporation may deem and treat the
registered Holder of shares of Series A Preferred Stock as the absolute owner
thereof for the purpose of any conversion hereof or any distribution to such
Holder, and for all other purposes, absent actual notice to the contrary.

      5. Registration of Transfers. Subject to the terms of the Stockholder's
Agreement, the Corporation shall register the transfer of any shares of Series A
Preferred Stock in the Series A Preferred Stock Register, upon surrender of
certificates evidencing such Shares to the Corporation at its address specified
herein. Upon any such registration or transfer, a new certificate evidencing the
shares of Series A Preferred Stock so transferred shall be issued to the
transferee and a new certificate evidencing the remaining portion of the shares
not so transferred, if any, shall be issued to the transferring Holder.

      6. Liquidation.

            (a) In the event of any Liquidation Event, the Holders of Series A
Preferred Stock shall be entitled to receive, prior and in preference to any
distribution of any of the assets

                                       -6-
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or surplus funds of the Corporation to the holders of Junior Securities by
reason of their ownership thereof, an amount per share in cash equal to the
greater of (i) the Stated Value for each share of Series A Preferred Stock then
held by them (as adjusted for any stock split, stock dividend, stock combination
or other similar transactions with respect to the Series A Preferred Stock),
plus all accrued but unpaid dividends (including, without duplication, dividends
added to Stated Value as provided in Section 3 above) on such Series A Preferred
Stock as of the date of such event, and (ii) the amount per share that would be
payable to a holder of Series A Preferred Stock had all shares of Series A
Preferred Stock been converted to Underlying Shares immediately prior to such
Liquidation Event (and taking into account Section 3(b), if applicable) (the
"SERIES A STOCK LIQUIDATION PREFERENCE"). If, upon the occurrence of a
Liquidation Event, the assets and funds thus distributed among the holders of
the Series A Preferred Stock shall be insufficient to permit the payment to such
Holders of the full Series A Stock Liquidation Preference, then the entire
assets and funds of the Corporation legally available for distribution shall be
distributed ratably among the Holders of the Series A Preferred Stock in
proportion to the aggregate Series A Stock Liquidation Preference that would
otherwise be payable to each of such Holders.

            (b) In the event of a Liquidation Event, following completion of the
distributions required by the first sentence of paragraph (a) of this Section 6,
if assets or surplus funds remain in the Corporation, the holders of the Common
Stock and other Junior Securities shall share in all remaining assets of the
Corporation.

            (c) The Corporation shall provide written notice of any Liquidation
Event or Fundamental Transaction to each record Holder not less than 45 days
prior to the payment date or effective date thereof; provided that such
information shall be made known to the public prior to or in connection with
such notice being provided to the Holders. At the request of any Holder, which
must be delivered prior to the effective date of a Fundamental Transaction (or,
if later, within five (5) Trading Days after such Holder receives notice of such
Fundamental Transaction from the Corporation), such Fundamental Transaction will
be treated as a Liquidation Event with respect to such Holder for the purposes
of this Section 6; provided, however, that if the consideration to be paid to
the holders of the Common Stock is not to be paid in cash, but rather in
securities or other property, then at the option of the Corporation, the amount
payable to the Holders pursuant to this Section 6(c) shall be either (i) in cash
or (ii) in the same securities or other property as is to be paid to the holders
of Common Stock so long as (a) such securities or other property consist
exclusively of common equity interests quoted on the Nasdaq Stock Market or
listed on the New York Stock Exchange, (b) the value of such common equity
interests shall be determined as 98% of the closing price of such common equity
interests on the Nasdaq Stock Market or the New York Stock Exchange, as the case
may be, on the Trading Day immediately preceding the consummation of such
Fundamental Transaction and (c) such common equity interests shall be freely
transferable by the Holders, without legal or contractual restrictions. At the
request of the original purchaser under the Purchase Agreement, prior to the
issuance of any common equity interests referred to in the preceding sentence,
counsel to the issuer of such common equity interests familiar with United
States federal securities laws shall provide the Purchaser with a legal opinion
to the effect that such common equity interests are transferable without legal
restriction under United States federal securities laws.

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            (d) In the event that, immediately prior to the closing of a
Liquidation Event the cash distributions required by subsection 6(a) have not
been made, the Corporation shall forthwith either: (i) cause such closing to be
postponed until such time as such cash distributions have been made, or (ii)
cancel such transaction, in which event the rights, preferences and privileges
of the holders of the Series A Preferred Stock shall revert to and be the same
as such rights, preferences and privileges existing immediately prior to the
date of the first notice by the Corporation required under subsection 6(c).

      7. Conversion; Redemption

            (a) Conversion at Option of Holder. At the option of any Holder, any
shares of Series A Preferred Stock may be converted into Common Stock based on
the Conversion Price then in effect for the Series A Preferred Stock; provided
that if less than 20% of the number of shares of Preferred Stock outstanding on
the date the Preferred Stock is first issued by the Corporation would remain
outstanding after any such conversion, then all shares must be converted at that
time. A Holder may convert shares of Series A Preferred Stock into Common Stock
pursuant to this paragraph at any time and from time to time after the Original
Issue Date, by delivering to the Corporation a conversion notice (the
"CONVERSION NOTICE"), in the form attached hereto as Exhibit A, appropriately
completed and duly signed, and the date any such Conversion Notice is delivered
to the Corporation (as determined in accordance with the notice provisions
hereof) is a "CONVERSION DATE."

            (b) Conversion at Option of Corporation. At any time that (i) the
average Closing Price for the 20 Trading Day period ending on the date of the
Conversion Notice (as defined below) equal to or exceeds $14.40 per share or
(ii) a Fundamental Transaction occurs that the Holders do not elect to treat as
a Liquidation Event, the Corporation may elect to require the Holders to convert
all shares of the Series A Preferred Stock into Common Stock based on the
Conversion Price by delivering an irrevocable written notice of such election to
the Holders (the "CONVERSION NOTICE"). The tenth (10th) Trading Day after the
delivery of such notice will be the "CONVERSION DATE" for such required
conversion. Notwithstanding the foregoing, (x) in the event of a conversion at
the option of the Corporation predicated on clause (i) of the first sentence of
this Section 7(b), the Corporation may not require any conversion under this
paragraph (and any notice thereof will be void), unless from the beginning of
such ten Trading Day period through the Conversion Date, the Closing Price for
each such Trading Day is equal to or exceeds $14.40 per share and (y) in the
event of a conversion at the option of the Corporation predicated on clause (i)
or (ii) of the first sentence of this Section 7(b), the Corporation may not
require any conversion under this paragraph (and any notice thereof will be
void), unless the Equity Conditions are satisfied (or waived in writing by the
applicable Holder) on each Trading Day with respect to all of the Underlying
Shares then issuable upon conversion in full of all outstanding Series A
Preferred Stock.

            (c) Redemption. On or after the fifth anniversary of the Closing
Date, the Corporation may, at its option, redeem any of the Series A Preferred
Stock owned by the Holders, for a cash purchase price equal to the Series A
Stock Liquidation Preference; provided that if less than 20% of the number of
shares of Preferred Stock outstanding on the date the Preferred Stock is first
issued by the Corporation would remain outstanding after any such redemption,
then all shares must be redeemed at that time.

                                       -8-
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      8. Mechanics of Conversion.

            (a) The number of Underlying Shares issuable upon any conversion of
shares of Series A Preferred Stock hereunder shall equal (A) the sum of (i) the
Stated Value of such shares of Series A Preferred Stock to be converted plus
(ii) the accrued and unpaid dividends on such shares of Series A Preferred Stock
that have not been added to the Stated Value on the Conversion Date, divided by
(B) the applicable Conversion Price on the Conversion Date.

            (b) Upon conversion of any shares of Series A Preferred Stock, the
Corporation shall promptly issue or cause to be issued and cause to be delivered
to or upon the written order of the Holder and in such name or names as the
Holder may designate a certificate for the Underlying Shares issuable upon such
conversion, free of restrictive legends unless such Underlying Shares are still
required to bear a restrictive legend; the Corporation shall use its
commercially reasonable efforts to cause the transfer agent to issue such
certificates on or before the sixth Trading Day after the Conversion Date. The
Holder shall be deemed to have become holder of record of such Underlying Shares
as of the Conversion Date. If the shares are then not required to bear a
restrictive legend, the Corporation shall, upon request of the Holder, deliver
Underlying Shares hereunder electronically through The Depository Trust
Corporation ("DTC") or another established clearing corporation performing
similar functions, and shall credit the number of shares of Common Stock to
which the Holder shall be entitled to the Holder's or its designee's balance
account with DTC through its Deposit Withdrawal Agent Commission System
("DWAC").

            (c) A Holder shall deliver the original certificate(s) evidencing
the Series A Preferred Stock being converted in connection with the conversion
of such Series A Preferred Stock. Upon surrender of a certificate following one
or more partial conversions, the Corporation shall promptly deliver to the
Holder a new certificate representing the remaining shares of Series A Preferred
Stock.

            (d) The Corporation's obligations to issue and deliver Underlying
Shares upon conversion of Series A Preferred Stock in accordance with the terms
hereof are absolute and unconditional, irrespective of any action or inaction by
any Holder to enforce the same, any waiver or consent with respect to any
provision hereof, the recovery of any judgment against any Person or any action
to enforce the same, or any setoff, counterclaim, recoupment, limitation or
termination, or any breach or alleged breach by any Holder or any other Person
of any obligation to the Corporation or any violation or alleged violation of
law by any Holder or any other Person, and irrespective of any other
circumstance which might otherwise limit such obligation of the Corporation to
any Holder in connection with the issuance of such Underlying Shares.

      9. Voting Rights; Director Designation.

            (a) Except as otherwise provided in this Section 9(a) or in Section
9(b) or as required by applicable law and subject to the Stockholder's
Agreement, the Holders of the Series A Preferred Stock shall be entitled to vote
on all matters on which holders of Common Stock are entitled to vote. For such
purposes, each Holder shall be entitled to a number of votes in respect of the
shares of Series A Preferred Stock owned of record by it equal to the number of
shares of Common Stock into which such shares of Series A Preferred Stock are
convertible by the Holders

                                      -9-
<PAGE>

as of the record date for the determination of stockholders entitled to vote on
such matter, or if no record date is established, at the date such vote is taken
or any written consent of stockholders is solicited. Except as otherwise
provided in this Section 9(a) or in Section 9(b), in any relevant agreement or
as required by applicable law, the holders of the Series A Preferred Stock and
Common Stock shall vote together as a single class on all matters submitted to a
vote or consent of stockholders; provided that so long as any shares of Series A
Preferred Stock are outstanding, the Corporation shall not, without the
affirmative vote of the Holders of a majority of the shares of Series A
Preferred Stock then outstanding, voting together as a separate class,

            (i) alter or change the powers, preferences or rights given to the
            Series A Preferred Stock or alter or amend this Certificate of
            Designation (whether by amendment of this Certificate of
            Designations or the Company's certificate of incorporation or other
            charter documents or through any reorganization, recapitalization,
            transfer of assets, consolidation, merger, dissolution, issue or
            sale of securities or any other voluntary action) or avoid or seek
            to avoid the observance or performance of any or the terms to be
            observed or performed hereunder by the Corporation;

            (ii) authorize or create any class of stock ranking as to dividends,
            redemption or distribution of assets upon a Liquidation Event or
            Fundamental Transaction senior to or otherwise pari passu with the
            Series A Preferred Stock;

            (iii) increase the authorized number of shares of Series A Preferred
            Stock;

            (iv) pay or declare any dividend or make any distribution on any
            Junior Securities, except pro rata stock dividends on the Common
            Stock payable in additional shares of Common Stock; or

            (v) enter into any agreement with respect to the foregoing.

      The protective rights set forth in (i) through (v) inclusive will
terminate and cease to apply on the first date on which there are outstanding
less than 20% of the number of shares of Series A Preferred Stock outstanding on
the date the Series A Preferred Stock is first issued by the Corporation.

            (b) The Holders of the Series A Preferred Stock shall not be
entitled nor have the right or power to vote in any election or removal, with or
without cause, of directors of the Corporation elected or removed generally by
the holders of the Common Stock (and any capital stock entitled to vote in the
election or removal of directors with the holders of the Common Stock) but shall
instead have the special voting rights set forth in this Section 9(b). Until
such time as the original purchaser under the Purchase Agreement, together with
its Affiliates, owns shares of Series A Preferred Stock that collectively
represent less than (y) 20% of the Post-Conversion Equity, the Series A
Preferred Stock voting together as a separate class shall be entitled to elect
two directors to the Corporation's board of directors and (z)10% of the
Post-Conversion Equity, the Series A Preferred Stock voting together as a
separate class shall be entitled to elect one director to the Corporation's
board of directors. The original purchaser of the Series A Preferred Stock may
remove any director elected pursuant to this Section 9(b) at any

                                      -10-
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time and from time to time, without cause (subject to the Bylaws of the
Corporation and any requirements of law), in its sole discretion. In the event a
director elected by the Series A Preferred Stock is removed, the vacancy in the
board of directors shall be filled by the original purchaser of Series A
Preferred Stock, and such action shall be taken only by vote or written consent
in lieu of a meeting of the holders of the Series A Preferred Stock or by any
remaining director or directors elected by the holders of Series A Preferred
Stock pursuant to this Section 9(b). On the date that the original purchaser
under the Purchase Agreement, together with its Affiliates, owns shares of
Series A Preferred Stock that collectively represent less than 10% of the
Post-Conversion Equity, then (i) the term of office of all directors elected
pursuant to the special voting rights set forth in this Section 9(b) shall be
deemed to terminate automatically and (ii) the rights set forth in this section
will terminate and cease to apply.

      10. Charges, Taxes and Expenses. Issuance of certificates for shares of
Series A Preferred Stock and for Underlying Shares issued on conversion of (or
otherwise in respect of) the Series A Preferred Stock shall be made without
charge to the Holders for any issue or transfer tax, withholding tax, transfer
agent fee or other incidental tax or expense in respect of the issuance of such
certificates, all of which taxes and expenses shall be paid by the Corporation.
The Holder shall be responsible for all other tax liability that may arise as a
result of holding or transferring the Series A Preferred Stock or receiving
Underlying Shares in respect of the Series A Preferred Stock.

      11. Replacement Certificates. If any certificate evidencing Series A
Preferred Stock or Underlying Shares is mutilated, lost, stolen or destroyed, or
a Holder fails to deliver such certificate as may otherwise be provided herein,
the Corporation shall issue or cause to be issued in exchange and substitution
for and upon cancellation thereof, or in lieu of and substitution for such
certificate, a new certificate, but only upon receipt of evidence reasonably
satisfactory to the Corporation of such loss, theft or destruction (in such
case) and, in each case, customary and reasonable indemnity, if requested.
Applicants for a new certificate under such circumstances shall also comply with
such other reasonable regulations and procedures and pay such other reasonable
third-party costs as the Corporation may prescribe.

      12. Reservation of Underlying Shares. The Corporation covenants that it
shall at all times reserve and keep available out of the aggregate of its
authorized but unissued and otherwise unreserved Common Stock, solely for the
purpose of enabling it to issue Underlying Shares as required hereunder, the
number of Underlying Shares which are then issuable and deliverable upon the
conversion of (and otherwise in respect of) all outstanding Series A Preferred
Stock (taking into account the adjustments of Section 13), free from preemptive
rights or any other contingent purchase rights of persons other than the Holder.
The Corporation covenants that all Underlying Shares so issuable and deliverable
shall, upon issuance in accordance with the terms hereof, be duly and validly
authorized, issued and fully paid and nonassessable. The Corporation covenants
that it shall use its best efforts to satisfy each of the Equity Conditions.

      13. Certain Adjustments. The Conversion Price is subject to adjustment
from time to time as set forth in this Section 13. Such adjustments shall be
made as the Conversion Price for all shares of Series A Preferred Stock from and
after the Original Issue Date.

                                      -11-
<PAGE>

            (a) Stock Dividends and Splits. If the Corporation, at any time
while Series A Preferred Stock is outstanding, (i) pays a stock dividend on its
Common Stock or otherwise makes a distribution on any class of capital stock
that is payable in shares of Common Stock, (ii) subdivides outstanding shares of
Common Stock into a larger number of shares, or (iii) combines outstanding
shares of Common Stock into a smaller number of shares, then in each such case
the applicable Conversion Price for Series A Preferred Stock shall be multiplied
by a fraction of which the numerator shall be the number of shares of Common
Stock outstanding immediately before such event and of which the denominator
shall be the number of shares of Common Stock outstanding immediately after such
event. Any adjustment made pursuant to clause (i) of this paragraph shall become
effective immediately after the record date for the determination of
stockholders entitled to receive such dividend or distribution, and any
adjustment pursuant to clause (ii) or (iii) of this paragraph shall become
effective immediately after the effective date of such subdivision or
combination.

            (b) Pro Rata Distributions. If the Corporation, at any time while
Series A Preferred Stock is outstanding, distributes or pays as a dividend to
holders of Common Stock (i) evidences of its indebtedness, (ii) any security
(other than a distribution of Common Stock covered by the preceding paragraph),
(iii) rights or warrants to subscribe for or purchase any security, or (iv) any
other asset (including, without limitation, cash) (in each case, "DISTRIBUTED
PROPERTY"), then in each such case the Corporation shall simultaneously deliver
to each Holder the Distributed Property that each such Holder would have been
entitled to receive in respect the number of Underlying Shares then issuable
pursuant to Section 7(a) above had the Holder been the record holder of such
Underlying Shares immediately prior to the applicable record or payment date.

            (c) Fundamental Transactions. If the Corporation, at any time while
Series A Preferred Stock is outstanding, effects any Fundamental Transaction,
then upon any subsequent conversion of Series A Preferred Stock, each Holder
shall have the right to receive, for each Underlying Share that would have been
issuable upon such conversion absent such Fundamental Transaction, the same kind
and amount of securities, cash or property as it could have been entitled to
receive upon the occurrence of such Fundamental Transaction if it had been,
immediately prior to such Fundamental Transaction, the holder of one share of
Common Stock (the "ALTERNATE CONSIDERATION"). For purposes of any such
conversion, the determination of the applicable Conversion Prices for the Series
A Preferred Stock shall be appropriately adjusted to apply to such Alternate
Consideration based on the amount of Alternate Consideration issuable in respect
of one share of Common Stock in such Fundamental Transaction, and the
Corporation shall apportion the Conversion Price among the Alternate
Consideration in a reasonable manner reflecting the relative value of any
different components of the Alternate Consideration. If holders of Common Stock
are given any choice as to the securities, cash or property to be received in a
Fundamental Transaction, then each Holder shall be given the same choice as to
the Alternate Consideration it receives upon any conversion of Series A
Preferred Stock following such Fundamental Transaction. To the extent necessary
to effectuate the foregoing provisions, any successor to the Corporation or
surviving entity in such Fundamental Transaction shall issue to the Holder a new
series of preferred stock consistent with the foregoing provisions and
evidencing the Holders' right to convert such preferred stock into Alternate
Consideration. The terms of any agreement pursuant to which a Fundamental
Transaction is effected shall include terms requiring any such successor or
surviving entity to comply with the provisions of this paragraph (c) and

                                      -12-
<PAGE>

insuring that the Series A Preferred Stock (or any such replacement security)
will be similarly adjusted upon any subsequent transaction analogous to a
Fundamental Transaction.

            (d) Calculations. All calculations under this Section 13 shall be
made to the nearest cent or the nearest 1/100th of a share, as applicable. The
number of shares of Common Stock outstanding at any given time shall not include
shares owned or held by or for the account of the Corporation, and the
disposition of any such shares shall be considered an issue or sale of Common
Stock.

            (e) Notice of Adjustments. Upon the occurrence of each adjustment
pursuant to this Section 13, the Corporation at its expense will promptly
compute such adjustment in accordance with the terms hereof and prepare a
certificate describing in reasonable detail such adjustment and the transactions
giving rise thereto, including all facts upon which such adjustment is based.
Upon written request, the Corporation will promptly deliver a copy of each such
certificate to each Holder and to the Corporation's Transfer Agent.

            (f) Notice of Corporate Events. If the Corporation (i) declares a
dividend (other than a dividend pursuant to Section 3 above) or any other
distribution of cash, securities or other property in respect of its Common
Stock, including without limitation any granting of rights or warrants to
subscribe for or purchase any capital stock of the Corporation or any
Subsidiary, (ii) authorizes or approves, enters into any agreement contemplating
or solicits stockholder approval for any Fundamental Transaction or (iii)
authorizes the voluntary dissolution, liquidation or winding up of the affairs
of the Corporation, then the Corporation shall deliver to each Holder a notice
describing the material terms and conditions of such transaction, at least 20
calendar days prior to the applicable record or effective date on which a Person
would need to hold Common Stock in order to participate in or vote with respect
to such transaction.

      14. Fractional Shares. The Corporation shall not be required to issue or
cause to be issued fractional Underlying Shares on conversion of Series A
Preferred Stock.

      15. Notices. Any and all notices or other communications or deliveries
hereunder (including without limitation any Conversion Notice) shall be in
writing and shall be deemed given and effective on the earliest of (i) the date
of transmission, if such notice or communication is delivered via facsimile at
the facsimile number specified in this Section prior to 4:30 p.m. (New York City
time) on a Trading Day, (ii) the next Trading Day after the date of
transmission, if such notice or communication is delivered via facsimile at the
facsimile number specified in this Section on a day that is not a Trading Day or
later than 4:30 p.m. (New York City time) on any Trading Day, (iii) the Trading
Day following the date of mailing, if sent by nationally recognized overnight
courier service, or (iv) upon actual receipt by the party to whom such notice is
required to be given. The addresses for such communications shall be: (i) if to
the Corporation, to One Riverway, Suite 1400, Houston, Texas 77056, facsimile:
713-292-2455, Attention: Corporate Secretary, or (ii) if to a Holder, to the
address or facsimile number appearing on the Corporation's stockholder records
or such other address or facsimile number as such Holder may provide to the
Corporation in accordance with this Section.

      16. Miscellaneous.

                                      -13-
<PAGE>

            (a) The headings herein are for convenience only, do not constitute
a part of this Certificate of Designations and shall not be deemed to limit or
affect any of the provisions hereof.

            (b) Any of the rights of the Holders of Series A Preferred Stock set
forth herein, including any Equity Conditions or any other similar conditions
for the Holders' benefit, may be waived by the affirmative vote of Holders of at
least a majority of the shares of Series A Preferred Stock then outstanding. No
waiver of any default with respect to any provision, condition or requirement of
this Certificate of Designations shall be deemed to be a continuing waiver in
the future or a waiver of any subsequent default or a waiver of any other
provision, condition or requirement hereof, nor shall any delay or omission of
either party to exercise any right hereunder in any manner impair the exercise
of any such right.

                                      -14-

<PAGE>

         IN WITNESS WHEREOF, WCA Waste Corporation has caused this Certificate
of Designations to be duly executed as of this 27th day of July, 2006.

                                      WCA WASTE CORPORATION

                                      By:  /s/ J. Edward Menger
                                           -------------------------------------
                                            Name: J. Edward Menger
                                            Title: Vice President & General
                                                   Counsel

                                      -15-

<PAGE>

                                                                       EXHIBIT A

                            FORM OF CONVERSION NOTICE

(To be executed by the registered Holder
in order to convert shares of Series A Preferred Stock)

The undersigned hereby elects to convert the number of shares of Series A
Convertible Preferred Stock indicated below into shares of common stock, par
value $0.01 per share (the "COMMON STOCK"), of WCA Waste Corporation, a Delaware
corporation (the "CORPORATION"), according to the conditions hereof, as of the
date written below.

                                  ______________________________________________
                                  Date to Effect Conversion

                                  ______________________________________________
                                  Number of shares of Series A Preferred Stock
                                  owned prior to Conversion

                                  ______________________________________________
                                  Number of shares of Series A Preferred Stock
                                  to be Converted

                                  ______________________________________________
                                  Stated Value of shares of Series A Preferred
                                  Stock to be Converted

                                  ______________________________________________
                                  Number of shares of Common Stock to be Issued

                                  ______________________________________________
                                  Applicable Conversion Price

                                  ______________________________________________
                                  Number of shares of Series A Preferred Stock
                                  subsequent to Conversion

                                  ______________________________________________
                                  Name of Holder

                                  By: __________________________________________
                                        Name:
                                        Title: