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* SUMMIT MIDSTREAM PARTNERS, LLC (Last) (First) (Middle) 1790 HUGHES LANDING BLVD., SUITE 500 (Street) THE WOODLANDS TX 77380 (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 REMARKS
	3. Date of Earliest Transaction (Month/Day/Year) 12/15/2015
	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)	12/15/2015		P		68,364	A	$15.86(1)	143,641	D
Common Units (Limited Partner Interests)	12/15/2015		P		7,519	A	$16.59(2)	151,160	D
Common Units (Limited Partner Interests)								5,293,571	I	BY: SUMMIT MIDSTREAM PARTNERS HOLDINGS, 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* SUMMIT MIDSTREAM PARTNERS, LLC (Last) (First) (Middle) 1790 HUGHES LANDING BLVD., SUITE 500 (Street) THE WOODLANDS TX 77380 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner Officer (give title below) X Other (specify below) SEE REMARKS

1. Name and Address of Reporting Person* SUMMIT MIDSTREAM PARTNERS HOLDINGS, LLC (Last) (First) (Middle) C/O SUMMIT MIDSTREAM PARTNERS LP 1790 HUGHES LANDING BLVD., SUITE 500 (Street) THE WOODLANDS TX 77380 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* ENERGY CAPITAL PARTNERS II, LLC (Last) (First) (Middle) 51 JOHN F. KENNEDY PARKWAY, SUITE 200 (Street) SHORT HILLS NJ 07078 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* ENERGY CAPITAL PARTNERS II, LP (Last) (First) (Middle) 51 JOHN F. KENNEDY PARKWAY, SUITE 200 (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 200 (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 200 (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 200 (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 200 (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. The price reported in Column 4 is a weighted average price. These common units were purchased in multiple transactions ranging from $15.21 to $16.17, inclusive. 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 range set forth above.

2. The price reported in Column 4 is a weighted average price. These common units were purchased in multiple transactions ranging from $16.24 to $16.90, inclusive. 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 range set forth above.

Remarks:

Energy Capital Partners II, LLC ("ECP"), Energy Capital Partners II, LP ("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"), 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"), collectively hold greater than a majority of the membership interest in Summit Midstream Partners, LLC ("Summit") and are entitled to elect five of the five directors of Summit. Summit is the sole member of Summit Midstream Partners Holdings, LLC ("SMPH") and as such, may be deemed to have indirect beneficial ownership of the 5,293,571 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 5,444,731 common units held by Summit and SMPH but disclaim beneficial ownership except to the extent of their pecuniary interest therein.

	/s/ Steven J. Newby, President and Chief Executive Officer, Summit Midstream Partners, LLC	12/16/2015
	/s/ Brock M. Degeyter, Executive Vice President, General Counsel and Secretary of Summit Midstream Partners Holdings, LLC	12/16/2015
	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/ Christopher M. Leininger, Deputy General Counsel	12/16/2015
	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/ Christopher M. Leininger, Deputy General Counsel	12/16/2015
	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/ Christopher M. Leininger, Deputy General Counsel	12/16/2015
	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/ Christopher M. Leininger, Deputy General Counsel	12/16/2015
	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/ Christopher M. Leininger, Deputy General Counsel	12/16/2015
	Energy Capital Partners II, LLC; By: /s/ Christopher M. Leininger, Deputy General Counsel	12/16/2015
	** Signature of Reporting Person	Date
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