Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
ENERGY CAPITAL PARTNERS II, LLC
  2. Issuer Name and Ticker or Trading Symbol
Summit Midstream Partners, LP [SMLP]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
See Footnotes
(Last)
(First)
(Middle)
51 JOHN F. KENNEDY PARKWAY, SUITE 1250
3. Date of Earliest Transaction (Month/Day/Year)
03/11/2016
(Street)

SHORT HILLS, NJ 07078
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
___ Form filed by One Reporting Person
_X_ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
COMMON UNITS (LIMITED PARTNER INTERESTS) 03/11/2016   P   208,033 (1) A $ 14.93 (2) (3) 4,457,829 I (4) BY: SMLP HOLDINGS, LLC
COMMON UNITS (LIMITED PARTNER INTERESTS) 03/14/2016   P   29,138 (1) A $ 14.88 (2) (5) 4,486,967 I (4) BY: SMLP HOLDINGS, LLC
COMMON UNITS (LIMITED PARTNER INTERESTS) 03/15/2016   P   82,122 (1) A $ 14.76 (2) (6) 4,569,089 I (4) BY: SMLP HOLDINGS, LLC
COMMON UNITS (LIMITED PARTNER INTERESTS)               29,703,421 I (7) BY: SUMMIT MIDSTREAM PARTNERS HOLDINGS, LLC
COMMON UNITS (LIMITED PARTNER INTERESTS)               151,160 I (7) BY: SUMMIT MIDSTREAM PARTNERS, LLC

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
ENERGY CAPITAL PARTNERS II, LLC
51 JOHN F. KENNEDY PARKWAY
SUITE 1250
SHORT HILLS, NJ 07078
  X   X   See Footnotes
ENERGY CAPITAL PARTNERS II, LP
51 JOHN F. KENNEDY PARKWAY
SUITE 1250
SHORT HILLS, NJ 07078
    X    
ENERGY CAPITAL PARTNERS II-A, LP
51 JOHN F. KENNEDY PARKWAY
SUITE 1250
SHORT HILLS, NJ 07078
    X    
ENERGY CAPITAL PARTNERS II-B IP, LP
51 JOHN F. KENNEDY PARKWAY
SUITE 1250
SHORT HILLS, NJ 07078
    X    
ENERGY CAPITAL PARTNERS II-C (SUMMIT IP), LP
51 JOHN F. KENNEDY PARKWAY
SUITE 1250
SHORT HILLS, NJ 07078
    X    
Energy Capital Partners II (Summit Co-Invest), LP
51 JOHN F. KENNEDY PARKWAY
SUITE 1250
SHORT HILLS, NJ 07078
    X    

Signatures

 Energy Capital Partners II, LP By: Energy Capital Partners GP II, LP Its: General Partner By: Energy Capital Partners II, LLC Its: General Partner By: /s/ Enoch O. Varner Title: Counsel   03/15/2016
**Signature of Reporting Person Date

 Energy Capital Partners II-A, LP By: Energy Capital Partners GP II, LP Its: General Partner By: Energy Capital Partners II, LLC Its: General Partner By: /s/ Enoch O. Varner Title: Counsel   03/15/2016
**Signature of Reporting Person Date

 Energy Capital Partners II-B IP, LP By: Energy Capital Partners GP II, LP Its: General Partner By: Energy Capital Partners II, LLC Its: General Partner By: /s/ Enoch O. Varner Title: Counsel   03/15/2016
**Signature of Reporting Person Date

 Energy Capital Partners II-C (Summit IP), LP By: Energy Capital Partners GP II, LP Its: General Partner By: Energy Capital Partners II, LLC Its: General Partner By: /s/ Enoch O. Varner Title: Counsel   03/15/2016
**Signature of Reporting Person Date

 Energy Capital Partners II (Summit Co-Invest), LP By: Energy Capital Partners GP II Co-Investment (Summit), LLC Its: General Partner By: Energy Capital Partners II, LLC Its: Managing Member By: /s/ Enoch O. Varner Title: Counsel   03/15/2016
**Signature of Reporting Person Date

 Energy Capital Partners II, LLC By: /s/ Enoch O. Varner Title: Counsel   03/15/2016
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) Units were purchased pursuant to a 10b5-1 plan entered into on December 15, 2015.
(2) The price reported in Column 4 is a weighted average price. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of common units purchased at each separate price within the ranges set forth in footnotes 3, 5 and 6.
(3) These common units were purchased in multiple transactions ranging from $14.84 to $15.05, inclusive.
(4) Energy Capital Partners II, LP ("ECP II") and certain of its parallel funds (collectively, the "SMLP Holdings Owners") collectively hold all of the membership interests in SMLP Holdings, LLC (''SMLP Holdings''). Energy Capital Partners II, LLC (''ECP'') indirectly controls the SMLP Holdings Owners. Accordingly, ECP and the SMLP Holdings Owners may be deemed to indirectly beneficially own the 4,569,089 common units held by SMLP Holdings but disclaim beneficial ownership except to the extent of their pecuniary interest therein.
(5) These common units were purchased in multiple transactions ranging from $14.62 to $14.98, inclusive.
(6) These common units were purchased in multiple transactions ranging from $14.32 to $14.95, inclusive.
(7) ECP indirectly controls ECP II, Energy Capital Partners II-A, LP (''ECP II-A''), Energy Capital Partners II-B IP, LP (''ECP II-B''), Energy Capital Partners II-C (Summit IP), LP (''ECP II-C'') and Energy Capital Partners II (Summit Co-Invest), LP ("ECP Summit Co-Invest" and together with ECP II, ECP II-A, ECP II-B and ECP II-C, the ''ECP Funds''), which collectively hold more than a majority of the membership interests in Summit Midstream Partners, LLC ("Summit") and are entitled to appoint all the directors of Summit. Summit is the sole member of Summit Midstream Partners Holdings, LLC (''SMPH'') and may be deemed to have indirect beneficial ownership of the 29,703,421 common units held by SMPH in addition to the 151,160 common units held directly. Accordingly, ECP and the ECP Funds may be deemed to indirectly beneficially own the 29,854,581 common units held by Summit and SMPH but disclaim beneficial ownership except to the extent of their pecuniary interest therein.

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