April 13, 2010
PAA Natural Gas Storage, L.P.
333 Clay Street, Suite 1500
Houston, Texas 77002
||RE: PAA NATURAL GAS STORAGE, L.P. REGISTRATION STATEMENT ON FORM S-1
Ladies and Gentlemen:
We have acted as counsel for PAA Natural Gas Storage, L.P. (the Partnership), a Delaware
limited partnership, with respect to certain legal matters in connection with the offer and sale of
common units representing limited partnership interests in the Partnership. We have also
participated in the preparation of a Registration Statement on Form S-1 and the amendments thereto
being collectively referred to herein as the Registration Statement to which this opinion is an
In connection therewith, we prepared the discussion (the Discussion) set forth under the
caption Material Income Tax Consequences in the Registration Statement.
All statements of legal conclusions contained in the Discussion, unless otherwise
noted, are our opinion with respect to the matters set forth therein as of the effective date of
the Registration Statement. In addition, we are of the opinion that the Discussion with respect to
those matters as to which no legal conclusions are provided is an accurate discussion of such
federal income tax matters (except for the representations and statements of fact by the
Partnership and its general partner, included in the Discussion, as to which we express no
We hereby consent to the filing of this opinion as an exhibit to the Registration Statement
and to the use of our name in the Registration Statement. This consent does not constitute an
admission that we are experts within the meaning of such term as used in the Securities Act of
1933, as amended, or the rules and regulations of the Securities and Exchange Commission issued
Very truly yours,
/s/ VINSON & ELKINS L.L.P.
Vinson & Elkins L.L.P.
Vinson & Elkins LLP Attorneys at Law Austin Beijing Dallas Dubai
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