Skip Navigation LinksDEP > Businesses > Program Integration > Pennsylvania Pipeline Portal > Mariner East II



Compliance and Enforcement Information

Statement on Settlement of Suspension of Drilling:

On August 9, 2017, the Pennsylvania Department of Environmental Protection reached an agreement with the Clean Air Council, Delaware Riverkeeper Network, and the Mountain Watershed Association, Inc. and Sunoco to resolve the temporary suspension of horizontal directional drilling (HDD) activity associated with construction of the Mariner East 2 pipeline (ME2) being built by Sunoco, LP.

That agreement can be viewed here

As part of the agreement reflected in the Environmental Hearing Board Stipulated Order dated August 9, 2017, Sunoco made revisions to some of the plans associated with the project, which are provided below:

Under the agreement, Sunoco will notify all landowners and water supply owners within 450 feet of future HDDs and provide additional opportunities for water testing for those owners.  Sunoco will also reevaluate at least 63 areas where HDD activity will take place. The reevaluations will include site specific geologic data for each location. The reevaluation reports will be posted to this webpage as they are received. 

HDD Reevaluation Reports

As part of the August 9, 2017 Environmental Hearing Board Stipulated Order, Sunoco is to provide DEP for review supplemental HDD Analysis. The HDD Reevaluation Table represents the supplemental information that DEP has received to date.

Public comments can be submitted within 14 calendar days from the date each HDD study has been posted on the table by sending an email to EP-Pipelines.

To view details of each HDD study and public comments, visit the HDD Reevaluation Table.

Inadvertent Returns:

The following spreadsheet details the inadvertent returns and the status of the incident for construction related to the Mariner East 2 pipeline. This information will be updated regularly. 

Press Releases:
Notices of Violation:
Consent Order and Agreement:


The PA Pipeline Project (PPP)/Mariner East II is an expansion of the existing Sunoco Mariner East pipeline system. Sunoco recently upgraded its existing Mariner East I pipeline to transport natural gas liquids from Ohio and the Pittsburgh area to its Marcus Hook Facility in Delaware County. More than 80% of the PPP will follow the same pipeline corridor as Mariner East I. The pipeline will traverse 17 counties in the southern tier of Pennsylvania.

Below is information on DEP's review and approval of the permit applications and other useful project information. The material is presented here to enable the public to readily review the application material, noted technical deficiencies and the company's responses to the technical deficiencies. The other material on this web page represents other documents associated with this project that the Department has received.

Additional documents, such as additional correspondence and emails between the DEP and the Applicant, may be in DEP files maintained at that regional office in which a given portion of the project is located. Persons wishing to review the entire file for this application should schedule a file review with the appropriate regional office (i.e. Southwest, South-Central or Southeast).

PPP/Mariner East II Project Overview Information Sheet

This information sheet provides a summary of the project and current status. 

Approved Chapter 105, Water Obstruction and Encroachment Permits and Chapter 102, Erosion and Sediment Control (E&S) Permits

On February 13, 2017, DEP approved the permit applications from Sunoco Pipeline L.P. for the PA Pipeline Project/Mariner East 2 pipeline project. DEP considered 17 Chapter 105 permit applications and 3 Chapter 102 permit applications for the project.

Addendums to Chapter 105, Water Obstruction and Encroachment Permits and Chapter 102, Erosion and Sediment Control (E&S) Permits

On February 6, 2017, DEP received updated application material from Sunoco Pipeline, L.P. in response to the technical deficiency items that were provided to the company on January 27, 2017, January 30, 2017 and on February 1, 2017.

Comment Response Document

The Comment Response Document summarizes the comments submitted to DEP by 29,835 commentators during the public participation process. These comments were submitted through the 2 comment periods and 5 public hearings that were held for the project.

Chapter 105, Water Obstruction and Encroachment Permits

On December 5, 2016, DEP received updated application material from Sunoco Pipeline, L.P. in response to the technical deficiency letters that were sent on September 6, 2016.

The following responses to technical deficiency letters and revised permit applications were reviewed.

Chapter 102, Erosion and Sediment Control General Permit for Earth Disturbance Associated with Oil and Gas Exploration, Production, Processing or Treatment Operations or Transmission Facilities (ESCGP-2), Notice of Intent (NOI)

On December 5, 2016, DEP received from Sunoco Pipeline, L.P. updated application material in response to the technical deficiency letters that were sent on September 6, 2016.

The following responses to technical deficiency letters and revised permit applications were reviewed.

PPP/Mariner East II Technical Deficiency Letters

On September 6, 2016, the DEP sent to Sunoco Pipeline, L.P. technical deficiency letters for the proposed PA Pipeline Project (PPP)/Mariner East II. These letters outlined technical deficiencies that were found during the technical review of the Chapter 105, Water Obstruction and Encroachment Permits and Chapter 102, Erosion and Sediment Control General Permit for Earth Disturbance Associated with Oil and Gas Exploration, Production, Processing or Treatment Operations or Transmission Facilities (ESCGP-2) Notices of Intent (NOI).

PPP/Mariner East II Shapefiles

The Department received revised shapefiles from Sunoco Pipeline, L.P. The revised files were provided to mirror the information provided in the technical deficiency responses.

These shapefiles are the GIS data layers associated with the permits that have been submitted for the proposed pipeline project. These shapefiles are not required as part of a permit application and are not commonly submitted but were provided to the Department by Sunoco Pipeline, L.P.

The files were accepted by the Department to aid in the review of the application material given the large scale of the project. The shapefiles ease the review by displaying some information contained in the hardcopy of the plans and application in a different format.

Public Hearings and Additional Comment Period

The Department is aware of the significant public interest regarding additional public participation opportunities for this project. The Department chose not to extend the comment period or offer an additional comment period on the applications. DEP held a 60-day public comment period in summer 2016, during which the Department conducted five public hearings and received feedback from more than 29,000 commentators. DEP did not hold an additional public comment period because the revisions Sunoco Pipeline LP made to the applications did not substantively change right-of-ways nor the corridors of the permits. The previously submitted comments were still applicable to those revisions. The Department extended the comment period at the outset of comment period and made the applications available online.

Historic Applications and Public Participation Information

On June 24, 2016, DEP published notice in the Pennsylvania Bulletin of the Chapter 105, Water Obstruction and Encroachment Permits. DEP accepted written comments through Wednesday, August 24, 2016. The permits associated with the comment period included:

On August 6, 2016, DEP provided notice in the Pennsylvania Bulletin that the Chapter 102, Erosion and Sediment Control General Permit for Earth Disturbance Associated with Oil and Gas Exploration, Production, Processing or Treatment Operations or Transmission Facilities (ESCGP-2), Notices of Intent (NOI) were under technical review for Sunoco Pipeline, L.P.'s PA Pipeline Project (PPP)/Mariner East II. DEP accepted written comments through Wednesday, August 24, 2016 on the permit applications.

DEP also held five public hearings to collect comments from citizens on the Chapter 105 Water Obstruction and Encroachment permit applications currently under technical review for PA Pipeline Project (PPP)/Mariner East II. Notice of these hearings was published in the Pennsylvania Bulletin on July 9, 2016.