FIRST AMENDMENT TO LEASE

This Amendment to Lease (this “ Amendment ”) is made as of the 25th day of October, 2011 (the “ Effective Date ”), by and between LIBERTY MA PORTFOLIO FEE LLC, with an address c/o Liberty Properties, One Liberty Square, Boston, Massachusetts 02109 (“ Landlord ”) and THERMOENERGY CORPORATION, a Delaware corporation, with an address of 10 New Bond Street, Worcester, MA 01606   (“Tenant”).

R E C I T A L S

A.           Landlord and Tenant entered into that certain Indenture of Lease, dated January __, 2008 (the “ Original Lease ”), pursuant to which Landlord leased to Tenant certain premises consisting of 19,200 rentable square feet in the building containing 221,111 total rentable square feet and located at 10 New Bond Street, Worcester, Massachusetts (the “ Original Premises ”) for a term that is scheduled to expire January 31, 2013, as more fully set forth in the Original Lease.

B.           Landlord and Tenant wish to enter into this Amendment to (i) expand the Original Premises to include 28,800 rentable square feet in the Building in the location shown on Exhibit A attached hereto (the “ Additional Premises ”), (ii) extend the Term of the Original Lease, and (iii) amend certain other terms and conditions of the Original Lease.

NOW, THEREFORE, in consideration of the mutual covenants herein contained, and for other good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, Landlord and Tenant hereby agree to amend the Lease as follows:

1.            Capitalized Terms .  All capitalized terms not otherwise modified or defined herein shall have the same meanings as are ascribed to them in the Lease. All references in the Lease to the “Lease” or “this Lease” or “the Lease” or “herein” or “hereunder” or similar terms or to any section thereof shall mean the Original Lease, or such section thereof, as amended by this Amendment.

2.            Extension of Term .  The Term of the Original Lease is hereby extended for a period commencing on February 1, 2013 and expiring on January 31, 2017(the “ Extended Term ”).

3.            Demise of Additional Premises .

(a)           In consideration of the rent and covenants set forth and contained herein on the part of Tenant to be paid, performed and observed, Landlord does hereby demise and lease to Tenant, and Tenant hereby leases from Landlord, the Additional Premises, commencing on October 1, 2011 (“ Additional Premises Commencement Date ”) and expiring on the last day of the Extended Term.  Except as otherwise expressly provided herein, Tenant’s lease of the Additional Premises shall be on all of the terms and conditions of the Original Lease.  Effective as of the Additional Premises Commencement Date, the rentable area of the Premises shall be 48,000 square feet.

(b)           Landlord shall deliver the Additional Premises