JOINT FILING AGREEMENT

Exhibit 7.18

JOINT FILING AGREEMENT

This Agreement is made this 9^th day of May, 2008, by and between each of the undersigned.

WHEREAS, each of the undersigned is required to file a Schedule 13D with respect to ownership of securities in Waste Industries USA, Inc.;

NOW, THEREFORE, the undersigned agree to file only one Schedule 13D reflecting their combined beneficial ownership of securities in Waste Industries USA, Inc., and each of the undersigned hereby designates and appoints each of Xxxxxx X. Xxxxx, Xx. and Xxxxxx X. Xxxxx, III as its attorney-in-fact with full power of substitution for each of them, each acting singly, to sign, file and make any amendments to such Schedule 13D.

This Agreement may be executed in two or more counterparts, each of which shall be deemed an original but all of which together will constitute one and the same instrument.

[Signature Pages Follow.]

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IN WITNESS WHEREOF, each of the undersigned has executed this Joint Filing Agreement as of the date first written above.

Dated: May 9, 2008
/s/ XXXXXX X. XXXXX, XX.
XXXXXX X. XXXXX, XX.
/s/ XXXXXX X. XXXXX, III
XXXXXX X. XXXXX, III
/s/ XXX X. XXXXX
XXX X. XXXXX
/s/ XXXXX X. XXXXX
XXXXX X. XXXXX
XXXXXX X. XXXXX, III IRREVOCABLE TRUST (TAILWALKER TRUST)
By:		/s/ Xxxxx X. Xxxxx
Name:		Xxxxx X. Xxxxx
Title:		Trustee
XXXXXX X. XXXXX, III IRREVOCABLE TRUST (TAILWALKER NON-GST TRUST)
By:		/s/ Xxxxx X. Xxxxx
Name:		Xxxxx X. Xxxxx
Title:		Trustee
XXXXXX X. XXXXX, XX. GRANTOR TRUST DATED MAY 1, 1995
By:		/s/ Xxxxxx X. Xxxxx, III
Name:		Xxxxxx X. Xxxxx, III
Title:		Trustee
By:		/s/ Xxxxx X. Xxxxx
Name:		Xxxxx X. Xxxxx
Title:		Trustee

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DAMAS II CHARITABLE REMAINDER UNITRUST U/A/D 12/13/07
By:		/s/ Xxxxxx Xxxx
Name:		Xxxxxx Xxxx
Title:		Trustee
PERRY 2007 IRREVOCABLE TRUST U/A/D DECEMBER 13, 2007
By:		/s/ Xxxxxxx Xxxxxxx Xxxxx
Name:		Xxxxxxx Xxxxxxx Perry
Title:		Trustee
C3 FOUNDATION, INC.
By:		/s/ Xxxxxx X. Xxxxx, III
Name:		Xxxxxx X. Xxxxx, III
Title:		Vice-President

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