SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* ENERGY CAPITAL PARTNERS II, LLC (Last) (First) (Middle) 51 JOHN F. KENNEDY PARKWAY SUITE 1250 (Street) SHORT HILLS NJ 07078 (City) (State) (Zip)	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) X Other (specify below) See Footnotes
	3. Date of Earliest Transaction (Month/Day/Year) 02/24/2016
	4. If Amendment, Date of 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

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)	02/24/2016		P		59,627(1)	A	$15.8(2)(3)	2,675,638	I(4)	BY: SMLP HOLDINGS, LLC
COMMON UNITS (LIMITED PARTNER INTERESTS)	02/25/2016		P		46,492(1)	A	$13.17(3)(5)	2,722,130	I(4)	BY: SMLP HOLDINGS, LLC
COMMON UNITS (LIMITED PARTNER INTERESTS)	02/25/2016		P		21,100(1)	A	$13.92(3)(6)	2,743,230	I(4)	BY: SMLP HOLDINGS, LLC
COMMON UNITS (LIMITED PARTNER INTERESTS)	02/25/2016		P		15,885(1)	A	$14.97(3)(7)	2,759,115	I(4)	BY: SMLP HOLDINGS, LLC
COMMON UNITS (LIMITED PARTNER INTERESTS)	02/25/2016		P		1,400(1)	A	$15.86(3)(8)	2,760,515	I(4)	BY: SMLP HOLDINGS, LLC
COMMON UNITS (LIMITED PARTNER INTERESTS)	02/26/2016		P		84,877(1)	A	$12.89(3)(9)	2,845,392	I(4)	BY: SMLP HOLDINGS, LLC
COMMON UNITS (LIMITED PARTNER INTERESTS)								29,703,421	I(10)	BY: SUMMIT MIDSTREAM PARTNERS HOLDINGS, LLC
COMMON UNITS (LIMITED PARTNER INTERESTS)								151,160	I(10)	BY: SUMMIT MIDSTREAM PARTNERS, LLC

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 Securities Underlying Derivative Security (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: 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

1. Name and Address of Reporting Person* ENERGY CAPITAL PARTNERS II, LLC (Last) (First) (Middle) 51 JOHN F. KENNEDY PARKWAY SUITE 1250 (Street) SHORT HILLS NJ 07078 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner Officer (give title below) X Other (specify below) See Footnotes

1. Name and Address of Reporting Person* ENERGY CAPITAL PARTNERS II, LP (Last) (First) (Middle) 51 JOHN F. KENNEDY PARKWAY SUITE 1250 (Street) SHORT HILLS NJ 07078 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* ENERGY CAPITAL PARTNERS II-A, LP (Last) (First) (Middle) 51 JOHN F. KENNEDY PARKWAY SUITE 1250 (Street) SHORT HILLS NJ 07078 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* ENERGY CAPITAL PARTNERS II-B IP, LP (Last) (First) (Middle) 51 JOHN F. KENNEDY PARKWAY SUITE 1250 (Street) SHORT HILLS NJ 07078 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* ENERGY CAPITAL PARTNERS II-C (SUMMIT IP), LP (Last) (First) (Middle) 51 JOHN F. KENNEDY PARKWAY SUITE 1250 (Street) SHORT HILLS NJ 07078 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Energy Capital Partners II (Summit Co-Invest), LP (Last) (First) (Middle) 51 JOHN F. KENNEDY PARKWAY SUITE 1250 (Street) SHORT HILLS NJ 07078 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. Units were purchased pursuant to a 10b5-1 plan entered into on December 15, 2015.

2. These common units were purchased in multiple transactions ranging from $15.25 to $16.05, inclusive.

3. 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 2, 5, 6, 7, 8 and 9.

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 2,845,392 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 $12.57 to $13.56, inclusive.

6. These common units were purchased in multiple transactions ranging from $13.57 to $14.55, inclusive.

7. These common units were purchased in multiple transactions ranging from $14.58 to $15.57, inclusive.

8. These common units were purchased in multiple transactions ranging from $15.69 to $16.05, inclusive.

9. These common units were purchased in multiple transactions ranging from $12.70 to $13.00, inclusive.

10. 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.

	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	02/26/2016
	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	02/26/2016
	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	02/26/2016
	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	02/26/2016
	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	02/26/2016
	Energy Capital Partners II, LLC By: /s/ Enoch O. Varner Title: Counsel	02/26/2016
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* 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).
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