**Exhibit 99.5**

 

**CERTIFICATION PURSUANT TO RULE 13a-14 OR 15d-14 OF THE SECURITIES**

**EXCHANGE ACT OF 1934**

 

I, William E. Andrew, certifythat:

 

1.     I have reviewed this annual report on Form 40-F of Penn WestEnergy Trust;

 

2.     Based on my knowledge, this report does not contain any untruestatement of a material fact or omit to state a material fact necessary to makethe statements made, in light of the circumstances under which such statementswere made, not misleading with respect to the period covered by this report;

 

3.     Based on my knowledge, the financial statements, and other financialinformation included in this report, fairly present in all material respectsthe financial condition, results of operations and cash flows of the issuer asof, and for, the periods presented in this report;

 

4.     The issuer’sother certifying officer and I are responsible for establishing and maintainingdisclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and15d-15(e)) and internal control over financial reporting (as defined inExchange Act Rules 13a-15(f) and 15d-15(f)) for the issuer and have:

 

(a)           Designed suchdisclosure controls and procedures, or caused such disclosure controls andprocedures to be designed under our supervision, to ensure that materialinformation relating to the issuer, including its consolidated subsidiaries, ismade known to us by others within those entities, particularly during theperiod in which this report is being prepared;

 

(b)           Designed such internalcontrol over financial reporting, or caused such internal control overfinancial reporting to be designed under our supervision, to provide reasonableassurance regarding the reliability of financial reporting and the preparationof financial statements for external purposes in accordance with generallyaccepted accounting principles;

 

(c)           Evaluated theeffectiveness of the issuer’s disclosure controls and procedures and presentedin this report our conclusions about the effectiveness of the disclosurecontrols and procedures, as of the end of the period covered by this reportbased on such evaluation; and

 

(d)           Disclosed in thisreport any change in the issuer’s internal control over financial reportingthat occurred during the period covered by the annual report that has materiallyaffected, or is reasonably likely to materially affect, the issuer’s internalcontrol over financial reporting; and

 

5.     The issuer’s other certifying officer and I have disclosed, based onour most recent evaluation of internal control over financial reporting, to theissuer’s auditors and the audit committee of the issuer’s board of directors(or persons performing the equivalent function):

 

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(a)   All significant deficiencies and material weaknesses in the design oroperation of internal control over financial reporting which are reasonablylikely to adversely affect the issuer’s ability to record, process, summarizeand report financial information; and

 

(b)   Any fraud, whether or not material, that involves management or otheremployees who have a significant role in the issuer’s internal control overfinancial reporting.

 

Dated:  March 27,2009

 

 
|   | /s/ William E.  Andrew                               |
|--------|------------------------------------------------------|
|   | William E.  Andrew                                   |
|   | Chief Executive  Officer of Penn West Petroleum Ltd. |

 

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