X0306 4 2019-03-22 0 0001549922 Summit Midstream Partners, LP SMLP 0001558915 ENERGY CAPITAL PARTNERS II, LLC 51 JOHN F. KENNEDY PARKWAY SUITE 200 SHORT HILLS NJ 07078 1 0 1 1 See Footnotes 0001456360 ENERGY CAPITAL PARTNERS II, LP 51 JOHN F. KENNEDY PARKWAY SUITE 200 SHORT HILLS NJ 07078 1 0 1 0 0001456364 ENERGY CAPITAL PARTNERS II-A, LP 51 JOHN F. KENNEDY PARKWAY SUITE 200 SHORT HILLS NJ 07078 1 0 1 0 0001558920 ENERGY CAPITAL PARTNERS II-B IP, LP 51 JOHN F. KENNEDY PARKWAY SUITE 200 SHORT HILLS NJ 07078 1 0 1 0 0001558930 ENERGY CAPITAL PARTNERS II-C (SUMMIT IP), LP 51 JOHN F. KENNEDY PARKWAY SUITE 200 SHORT HILLS NJ 07078 1 0 1 0 0001532708 Energy Capital Partners II (Summit Co-Invest), LP 51 JOHN F. KENNEDY PARKWAY SUITE 200 SHORT HILLS NJ 07078 1 0 1 0 Common Units (Limited Partner Interests) 2019-03-22 4 A 0 8750000 A 40520408 I See footnotes On March 22, 2019, pursuant to that certain Equity Restructuring Agreement, dated as of February 25, 2019, the incentive distribution rights ("IDRs") and the approximately 2% general partner interest in the Issuer held by Summit Midstream GP, LLC (the "General Partner") were converted into (i) 8,750,000 newly issued common units of the Issuer and (ii) a non-economic general partner interest in the Issuer. Immediately following the issuance of the 8,750,000 common units, the General Partner distributed the units to its sole member, Summit Midstream Partners Holdings, LLC ("SMPH"). Following the transactions reported herein, includes 34,604,581 common units held by SMPH and 5,915,827 common units held by SMLP Holdings, LLC ("SMLP Holdings"). Energy Capital Partners II, LP ("ECP II") and certain of its parallel funds (collectively, the "SMLP Holdings Owners") collectively hold all of the SMPH membership interests in 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 5,915,827 common units held by SMLP Holdings but disclaim beneficial ownership except to the extent of their pecuniary interest therein. 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 SMPH. Accordingly, ECP and the ECP Funds may be deemed to indirectly beneficially own the 34,604,581 common units held by 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 2019-03-26 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 2019-03-26 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 2019-03-26 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 2019-03-26 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 2019-03-26 Energy Capital Partners II, LLC By: /s/ Enoch O. Varner Title: Counsel 2019-03-26