Exhibit 23.10

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the reference to our firm under the caption “Experts” and to the use of our report dated March 14, 2005 relating to Covanta Energy Corporation in Amendment No. 4 to the Registration Statement (Form S-1 No. 333-120755) and related Prospectus of Covanta Holding Corporation (formerly known as Danielson Holding Corporation) for the registration of up to 5,700,000 shares of its common stock issuable upon exercise of warrants to purchase common stock.

/s/ Ernst & Young LLP

MetroPark, New Jersey
January 25, 2006