13D Filing: Lightfoot Capital Partners, LP and Arc Logistics Partners LP (ARCX)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 1)

Arc Logistics
Partners LP

(Name of Issuer)

Common Units representing limited partner interests

(Title of Class of Securities)

03879N 101

(CUSIP
Number)

Steven C. Schnitzer

725 Fifth Avenue, 19th Floor

New York, NY 10022

(212)
993-1290

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

August 29, 2017

(Date of Event which Requires Filing of this Statement)

If the filing
person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following
box.    ☐

CUSIP No. 03879N 101

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CUSIP No. 03879N 101

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AMENDMENT NO. 1 TO SCHEDULE 13D

This Amendment No. 1 to Schedule 13D (this Amendment) amends and restates the Schedule 13D initially filed with the
Securities and Exchange Commission on November 18, 2016 and relates to the beneficial ownership of the Reporting Persons (as defined herein) of the common units representing limited partner interests (the Common Units) of Arc
Logistics Partners LP, a Delaware limited partnership (the Issuer).

The purpose of this Amendment is to
(i) update the plans of the Reporting Persons with respect to the Common Units and the Issuer and (ii) update the Reporting Persons contracts with respect to the Common Units.

This statement on Schedule 13D (the Schedule
13D) relates to Common Units of the Issuer. The Issuers principal executive offices are located at 725 Fifth Avenue, 19th Floor, New York, NY 10022.

(a), (f) This Schedule 13D is being filed jointly by
Lightfoot Capital Partners, LP, a Delaware limited partnership (LCP LP), and Lightfoot Capital Partners GP LLC, a Delaware limited liability company and the general partner of LCP LP (LCP GP and, together with
LCP LP, the Reporting Persons).

(b) The business address for each Reporting Person is 725 Fifth Avenue, 19th Floor, New
York, NY 10022.

(c) LCP LP is a private investment vehicle that focuses on investing directly in master limited partnership-qualifying
businesses and assets.

LCP GP is the general partner of LCP LP. LCP GP owns 100% of the limited liability company interests in Arc
Logistics GP LLC, the general partner of the Issuer (the General Partner). Information with respect to the managers and Series A Members of LCP GP, including, as applicable, name, principal business, residence or business address,
present principal occupation or employment, the name, principal business and address of any corporation or other organization in which such employment is conducted, citizenship and state or other place of organization, is listed on the attached
Schedule A, which is incorporated in this Schedule 13D by reference.

(d), (e) During the last five years, none of the Reporting
Persons nor, to the knowledge of LCP GP, any manager or Series A Member of LCP GP, has been (i) convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors) or (ii) a party to a civil proceeding of a judicial
or administrative body of competent jurisdiction and as a result of such proceeding was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities
laws or finding any violation with respect to such laws.

In connection with the Issuers
initial public offering, and pursuant to the Contribution Agreement dated October 25, 2013 by and among the Issuer, the General Partner, LCP LP, Center Terminal Company-Cleveland, Gulf Coast Asphalt Company, L.L.C., Arc Terminals GP LLC
(Arc Terminals GP), Arc Terminals LP (Arc Terminals), Arc Terminals Holdings LLC and Arc Terminals Mississippi Holdings LLC, LCP LP contributed all of its limited partner interests in Arc Terminals and all of
its limited liability company interests in Arc Terminals GP to the Issuer in exchange for 68,617 Common Units and 5,146,264 subordinated units representing limited partner interests (Subordinated Units) of the Issuer.

On November 16, 2016, the Subordinated Units converted into Common Units on a one-for-one basis upon the satisfaction of certain tests
set forth in the Issuers First Amended and Restated Agreement of Limited Partnership (the Partnership Agreement).

The acquisitions of Common Units by the Reporting Persons were
undertaken for investment purposes. LCP GP owns a 100% limited liability company interest in the General Partner.

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(a)-(j) On August 29, 2017, the Issuer, the General Partner, the Reporting Persons,
Zenith Energy U.S., L.P., a Delaware limited partnership (Parent), Zenith Energy U.S. GP, LLC, a Delaware limited liability company and the general partner of Parent (Parent GP), Zenith Energy U.S. Logistics
Holdings, LLC, a Delaware limited liability company and a subsidiary of Parent (Holdings), and Zenith Energy U.S. Logistics, LLC, a Delaware limited liability company and a subsidiary of Holdings (Merger Sub
and, together with Parent, Parent GP and Holdings, the Parent Entities), entered into a Purchase Agreement and Plan of Merger (Merger Agreement) pursuant to which Merger Sub will, upon the terms and subject to
the conditions thereof, merge with and into the Issuer (the Merger), with the Issuer surviving the Merger as a subsidiary of Parent, and LCP GP will transfer to Holdings 100% of the issued and outstanding membership interests in
the General Partner, including all rights and obligations relating thereto and all economic and capital interest therein (the GP Equity Transfer).

Upon the Merger and GP Equity Transfer becoming effective (the Effective Time), (a) each Common Unit issued and
outstanding immediately prior to the Effective Time (other than those Common Units owned by the Reporting Persons (the Sponsor Units)) will be converted into the right to receive an amount in cash equal to $16.50 per Common Unit,
no longer be outstanding, automatically be cancelled and cease to exist, (b) each Sponsor Unit issued and outstanding immediately prior to the Effective Time will be converted into the right to receive an amount in cash equal to $14.50 per
Common Unit, no longer be outstanding, automatically be cancelled and cease to exist, in each case, upon the terms and subject to the conditions set forth in the Merger Agreement and (c) Holdings will (or Parent will on Holdings behalf)
pay to LCP GP $94,500,000 in cash in exchange for 100% of the membership interests in the General Partner acquired by Holdings in connection with the GP Equity Transfer.

The consummation of the Merger and the GP Equity Transfer is subject to the satisfaction or waiver of a number of conditions, including, among
others, approval by the holders of a majority of the outstanding Common Units, the expiration of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, and Parents receipt of the written resignation of
each member of the board of directors of the General Partner and each officer of the General Partner, to be effective as of the Effective Time. Additionally, the consummation of the Merger and the GP Equity Transfer are subject to (i) the
closing of the purchase by Holdings and the Reporting Persons from EFS Midstream Holdings LLC of certain of the interests in Arc Terminals Joliet Holdings LLC, which indirectly owns among other things a crude oil unloading facility and a 4-mile
crude oil pipeline in Joliet, Illinois, and (ii) the closing of the purchase by Holdings of a 5.5% interest (and, subject to certain conditions, an additional 4.2% interest) in Gulf LNG Holdings Group, LLC, which owns a liquefied natural gas
regasification and storage facility in Pascagoula, Mississippi, from the LCP LP.

On August 29, 2017, the Reporting Persons entered
into a support agreement (the Lightfoot Support Agreement) with the Parent Entities. Under the Lightfoot Support Agreement, the Lightfoot Entities agree to vote the Sponsor Units for approval of the Merger Agreement and any
related proposal necessary or desirable for the consummation of the transactions and against any alternative proposal, including any superior proposal. The Lightfoot Support Agreement terminates on the earlier to occur of (i) mutual agreement
of the parties thereto and (ii) termination of the Merger Agreement in accordance with its terms.

The Merger is targeted to close at
the end of the fourth quarter of 2017 or early in the first quarter of 2018, and is subject to the General Partners and Parent GPs right to terminate the Merger Agreement if the Merger has not been consummated on or before
February 7, 2018, subject to extension at Parent GPs election to March 1, 2018, in certain circumstances as specified in the Merger Agreement (the Outside Date).

From the date of the Merger Agreement until the Effective Time, the Issuer plans to declare and pay quarterly distributions in the ordinary
course of business and consistent with past practices. Assuming that the Merger has not closed by January 26, 2018, the Issuer expects that it would declare a distribution associated with the fourth quarter of 2017 on or about January 26,
2018, to be paid on or about February 15, 2018 to holders of record on February 8, 2018. If, as anticipated, the Merger closes prior to the record date for the distribution associated with the fourth quarter of 2017, then none of the
holders as of immediately prior to the closing of the Merger will receive any distribution associated with the fourth quarter of 2017. If, alternatively, the Merger does not close by the record date for the distribution associated with the fourth
quarter of 2017, then the Issuer will pay the fourth quarter distribution to holders of record as of the record date, irrespective of whether the Merger closes thereafter or whether either party terminates the Merger Agreement after the Outside
Date.

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If the Merger is completed, the Common Units will be delisted from the New York Stock Exchange
and deregistered under the Securities Exchange Act of 1934, as amended (the Exchange Act) (via termination of registration pursuant to Section 12(g) of the Exchange Act).

(a), (b) Based on 19,545,944 Common Units
outstanding as of August 28, 2017.

Lightfoot Capital Partners, LP

Lightfoot Capital Partners GP LLC

Management and control of LCP LP is vested in its general partner, LCP GP, which is in turn managed and
controlled by its board of managers consisting of Jonathan Cohen, Vincent T. Cubbage, Eric Scheyer, Joshua Tarnow, John Pugh and Alec Litowitz and its Series A Members consisting of Vincent T. Cubbage, MCP Lightfoot Investment LLC, Atlas Lightfoot,
LLC, LB GPS Lightfoot L.L.C. and EFS LF Holdings, LLC. LCP GP may therefore be deemed to beneficially own Common Units owned directly by LCP LP. Certain of the managers and Series A Members of LCP GP own equity interests in the Issuer.

(c) Except as set forth in this Schedule 13D, the Reporting Persons and the managers and Series A Members of LCP GP have not effected any
transactions in the class of securities described herein during the past 60 days.

(d) Not applicable.

(e) Not applicable.

Joint Filing Agreement

A Joint
Filing Agreement, dated September 6, 2017, by and between the Reporting Persons has been executed. A copy of the Joint Filing Agreement is attached hereto as Exhibit 99.1 to this Schedule 13D and is incorporated herein by reference.

Partnership Agreement

On
November 12, 2013, in connection with the closing of the Issuers initial public offering, the Issuer amended and restated its Agreement of Limited Partnership. The Partnership Agreement describes the terms and rights of the Common Units,
including with respect to voting and cash distributions. The foregoing description of the Partnership Agreement is qualified in its entirety by reference to the full text of the Partnership Agreement, which is listed as Exhibit 99.2 and incorporated
herein by reference.

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Merger Agreement

On August 29, 2017, the Reporting Persons, the Issuer, the General Partner and the Parent Entities entered into the Merger Agreement. The
Merger Agreement sets forth the terms and conditions for consummation of the Merger and the GP Equity Transfer. The foregoing description of the Merger Agreement is qualified in its entirety by reference to the full text of the Merger Agreement,
which is listed as Exhibit 99.3 and incorporated herein by reference.

Lightfoot Support Agreement

On August 29, 2017, the Reporting Persons entered into the Lightfoot Support Agreement with the Parent Entities. Under the Lightfoot
Support Agreement, the Lightfoot Entities have agreed to vote the Sponsor Units for approval of the Merger Agreement and any related proposal necessary or desirable for the consummation of the transactions and against any alternative proposal,
including any superior proposal. The foregoing description of the Lightfoot Support Agreement is qualified in its entirety by reference to the full text of the Lightfoot Support Agreement, which is listed as Exhibit 99.4 and incorporated herein by
reference.

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SIGNATURES

After reasonable inquiry and to the best of its knowledge and belief, each of the undersigned certifies that the information with respect to
it set forth in this statement is true, complete and correct.

Dated: September 6, 2017

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