SecProbe.io

March 27, 2012
 Via E-mail

Mr. James H. Haddox, Chief Financial Officer Quanta Services, Inc. 2800 Post Oak Blvd., Suite 2600
Houston, TX  77056

Re: Quanta Services, Inc.
 Form 10-K for the year ended December 31, 2011
Filed February 29, 2012 File No. 1-13831

Dear Mr. Haddox:
 We have reviewed your filing and have the following comments.  In some of our
comments, we may ask you to provide us with  information so we may better understand your
disclosure.
 Please respond to this letter within te n business days by providing the requested
information, or by advising us when you will provide the requested response.  If you do not believe our comments apply to your facts and circ umstances please tell us  why in your response.
 After reviewing the information you provide in response to these comments, we may
have additional comments.  Form 10-K for the year ended December 31, 2011

 Notes to the Consolidated Financial Statements

 5.  Goodwill and Other Intangible Assets, page 97

 1. With a view towards future disclosure, please provide us with a specific and
comprehensive discussion of the under lyi ng reasons for and impact of your operating
unit reorganizations in fiscal 2011.  In this regard, please discuss how the goodwill
impairment testing for these units changed fr om 2010 to 2011.  In addition, please clarify
why the reorganization did not cause a reclas sification of your segment results in prior
periods.
 12.  Employee Benefit Plans, page 111

 2. We note that there have been fluctuations in  the amount of your c ontributions to each
plan year over year.  In futu re filings please provide a descri ption of the nature and effect

Mr. James H. Haddox Quanta Services, Inc. March 27, 2012 Page 2

 of any significant changes that affect the comparability of your contributions.  Please
refer to ASC Topic 715-80-50-6.
 3. We also note that you have made contribu tions to multi-employer defined contribution
plans and these contributions have increased year over year.  In future filings please provide a description of the nature and effect  of any significant ch anges that affect the
comparability of your contributions.  Please refer to ASC Topic 715-80-50-11
 14. Commitments and Contingencies, page 114

 Leases, page 115

 4. We note that you lease land, buildings and equi pment under operating leases.  Please tell
us how you evaluated the requirements of ASC Topic 840-10-25-14.  In this regard,
please explain whether these leases contain nonperformance related default covenants,
material adverse change clauses, cross-defau lt provisions or subjective default provisions,
and if so, how you evaluated su ch covenants and provisions.
 Litigation and Claims, page 115

5. Your disclosure indicates that you are unable to estimate the amount of a possible loss or
range of loss relating to both the Californ ia Fire Litigation and California Fire Claim
matters.  We have the following comments related to this disclosure:
 Please provide us with a specific and co mprehensive discussion regarding why you
cannot estimate your reasonably possible loss or range of loss in excess of amounts
accrued for each matter.  We remind you that ASC 450 does not require estimation with confidence or precision.
 If you conclude that you cannot estimate the reasonably possible loss or range of
loss please: (1) explain to us the procedures you undertak e on a quarterly basis to
attempt to develop an estimate disclosure and (2) what specific factors are causing the inability to estimate and when you exp ect those factors to be alleviated.  We
recognize that there are a number of uncerta inties and potential outcomes associated
with loss contingencies.  None theless, an effort should be made to develop estimates
for purposes of disclosures, including dete rmining which of the potential outcomes
are reasonably possible and what the reas onably possible range of losses would be
for those reasonably possible outcomes.
 Please clarify if the amount the USDA may s eek for past and future restoration and
other damages could exceed $51.3 million.
 Future disclosures regarding reasonably  possible losses in excess of amounts
accrued may be provided on an aggregated basis.

Mr. James H. Haddox Quanta Services, Inc. March 27, 2012 Page 3

 Collective Bargaining Agreements, page 119

 6. We note your disclosure that th e amount of additional funds that you may be obligated to
contribute to plans that are in the “endangered,” “seriously  endangered” or “critical”
status cannot be estimated because such amount s will “likely” be based on future levels
of work.  With a view towards future disclo sure, please clarify if additional funds may be
based on past levels of work or past cont ributions and, if so, how you have estimated
your potential obligations.

7. We note your disclosure that the amount of  your withdrawal liab ility for the Central
States plan could increase substantially.  With  a view towards future disclosure, please
provide us with a specific and comprehens ive discussion regarding why the amount of a
potential increase cannot be determined.  Please tell us what consideration you have
given to the range of reasonably pos sible losses.  Reference ASC 450.
 We urge all persons who are responsible for th e accuracy and adequacy of the disclosure
in the filing to be certain that the filing include s the information the Securities Exchange Act of
1934 and all applicable Exchange Act rules requir e.  Since the company and its management are
in possession of all facts relating to a company’s disclosure, they are responsible for the accuracy
and adequacy of the disclosures they have made.

 In responding to our comments, please provi de a written statement from the company
acknowledging that:
 the company is responsible for the adequacy  and accuracy of the disclosure in the
filing;
 staff comments or changes to disclosure  in response to staff comments do not
foreclose the Commission from taking any action with respect to the filing; and

 the company may not assert staff comments as a defense in any proceeding initiated
by the Commission or any person under the federal securities laws of the United
States.

You may contact Mindy Hooker at (202) 551-3732, Tricia Armelin at (202) 551-3747 or
me at (202) 551-3768 with any questions.
Sincerely,
   /s/ John Cash
John Cash Branch Chief