A list of frequently asked questions about the environmental remediation of the former Harrison MGP site. Topics include location of the project site, its history, the remediation work done so far, and upcoming work for the site.

Updated July 29, 2020

What was a Manufactured Gas Plant (MGP)?

Prior to the widespread availability of natural gas, gas was “manufactured” through a process of heating coal in specialized ovens. These facilities, called Manufactured Gas Plants (MGP), were common in many urban areas of the United States during the late nineteenth and early twentieth centuries.  Manufactured gas was used for residential and street lighting and cooking. The manufactured gas process produced byproducts, such as coal tar and other chemicals that were also used in the chemical, dye and pharmaceutical industries. An unintended consequence of the MGP industry was the effects from coal tar and various byproducts to the environment.

About the Site Remediation

What is the extent of impacts to be remediated? 

The entire 32-acre Site housed the former manufactured gas plant and related operations. As a result, the impacts extend across a substantial portion of the Site. Some of these impacts were remediated between 2004-2018 but more work is needed and planned. 

What are the contaminants?

The source of the MGP materials is the former MGP operations. Some by-products of the gas manufacturing process, including coal tar residues and oils, are found in the soil and groundwater at the Site. Compounds of concern present in coal tar and oils include benzene, toluene, ethylbenzene and xylene(s) (or BTEX), naphthalene, and polycyclic aromatic hydrocarbons (or PAHs).

What remediation work has been completed to date?

Since 1999, PSE&G has installed and sampled regularly more than 60 onsite and off-site monitoring wells to determine the MGP impacts to groundwater. At PSE&G’s request, NJDEP first authorized in 2001 and then updated in 2002 a Classification Exception Area (CEA) and Well Restriction Area (WRA) for the entire Site. The CEA identifies where groundwater does not comply with NJDEP standards. A WRA restricts the use of groundwater in a CEA for potable use. 

PSE&G performed Interim Remediation Actions (IRMs) in 2004, 2008, 2009, 2010 and 2012 that included a River Front Remediation conducted between the Site and the Passaic River to address migration of Site contaminants in the overburden. In 2018, a pilot project, focused on remediating 1.8 acres of the 32-acre site, was successfully completed. 

What remediation is planned?

In two phases, the Harrison former MGP Site is being addressed with a combination of different remedies, including the treatment of soils in place, referred to as In Situ Stabilization (ISS).  The first phase of work began in July 2020.

What is In Situ Stabilization Solidification (ISS)?

It is a proven environmental remediation process that involves mixing of contaminated soil in place with stabilizing agents, such as Portland cement and blast furnace slag. It solidifies the soil below ground.

Is NJDEP supervising the work?

In 2012, NJDEP fully implemented the Licensed Site Remediation Professional (LSRP) program. LSRPs provide guidance and oversight to ensure projects like this are performed in accordance with state regulations. The LSRP for this site is John Bolan with PS&S.

The work plan for the Site remediation was reviewed and approved by the LSRP and then submitted to NJDEP, which provided no comments.  After each phase of work is completed, PSE&G develops a report documenting its actions. The report is reviewed and approved by the LSRP and submitted to the NJDEP.

Who is responsible for the remediation of the Site?

PSE&G is the responsible party.

If steel sheeting was installed along the river front. Why is this current work necessary?

In 2004-2005, a River Front Remediation was conducted between the Site and the Passaic River to address migration of Site contaminants in the overburden. The interior of the Site still needs to be addressed.

About the Pilot Project Remedy

How do you know the pilot study was successful?

The mixture of stabilizing agents used in the ISS process varies from site to site and is determined based on the conditions of the soil and groundwater. The success of the ISS remedy was determined by taking cylinder samples as the mixture cures and assessing whether the stabilized soils meets a minimum strength, maximum hydraulic conductivity, and leachability. Testing to date has determined the process worked as designed.

Dust Management, Odor Mitigation and Air Monitoring

Does PSE&G control dust during remediation?

Yes. Dust control measures such as water misting, and foaming are performed as needed during soil intrusive work. 

Are odors associated with the remediation work?

Soils containing MGP-related materials sometimes have an odor similar to that of mothballs or fresh asphalt. These odors can be detected by people at levels below what can be detected by an air monitoring instrument and well below what would be considered a health concern. Dust and odor control measures (such as water mist, foam spray, plastic sheeting and sand cover) are commonly used to control potential dust and odors during excavation and non-work periods.

Odor assessments will be performed at least twice daily, or more frequently as required, to identify and manage observed odors at the source before they travelled off site.

If you have a concern about odors, or just a question, we encourage you to call the Project Information Line at (855) 356-2383 or email the team at comments@HarrisonMGP.com. Kelly Henry is the community liaison working on behalf of PSE&G for the project and will be the first person to respond to your call or email.

What is the foam used to control dust and odors and what is in it?

The foam to be used at the project site is made from a Rusmar brand foam concentrate, specifically Rusmar formulas AC645 and AC900. Both serve to form a barrier between contaminants and the atmosphere and are applied either during or after active excavation to provide an immediate and effective barrier to vapors and help to minimize odors. Both are completely biodegradable. Neither formula has an inherent odor; however, a scent (such as wintergreen or vanilla) may be added.

Rusmar AC-645: http://www.rusmarinc.com/_assets/img/PDFs/new/AC-645-RusFoamOC-MSDS.pdf

Rusmar AC-900: http://www.rusmarinc.com/_assets/img/PDFs/new/AC-900-RusFoam-LM-MSDS.pdf

In addition, Biosolve Pinkwater, a surfactant, may be used as an additional vapor suppression product: https://biosolve.com/sites/default/files/SDS%20BioSolve%20Pinkwater%202016R.pdf

Will air monitoring be performed?

Yes. An air monitoring plan specific to the site’s activity and constituents of concern has been developed for each phase of work. Air monitoring is performed when digging, or any soil disturbance activity, is performed. 

What do the air monitors do?

Air monitoring stations will be installed along all sides of the work area perimeter and between the project area and the closest building when remediation work is being performed. The stations house two monitoring devices that will operate continuously during active work hours. One device is a photoionization detector (PID), which is a type of vapor detector. It monitors and records total volatile organic compounds (TVOCs). The other device is a real-time particulate matter meter that monitors for dust.

The stations are closely monitored to ensure that the project stays below health-based action levels. A summary of air monitoring results is posted to this website after results are confirmed by an independent laboratory.

Where will the air monitors be stationed?

When remediation work is performed, there are always a minimum of five air monitoring stations. One monitoring station is located along each of the north, east, south and west sides of the work area perimeter, and a fifth will be placed by the laboratory building’s air-intake.

Will air monitoring be performed when work is not being done?

We will perform air monitoring only while our remediation work is being performed.

How quickly do you get air monitoring results?

While remediation is being performed, perimeter air monitoring equipment provides real-time readings, continually measuring and recording TVOCs and PM-100 to the project team during work hours.

Additionally, an air sample is collected weekly during remediation activities and sent for analysis at a New Jersey certified laboratory. These results are expected within three weeks of the collection date, and the current running average is posted on the Air Monitoring page.

The Air Monitoring page on the website provides only data for Benzene and Naphthalene. Are they the only contaminants you monitor?

No. In accordance with the Perimeter Air Monitoring Plan, air samples are analyzed for the full suite of volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs) and metals.

If levels for Benzene and Naphthalene are below the PAMP action level, then there is no indication that any of the remaining contaminants are at risk of exceeding the residential health-based standards. These contaminants are tracked and can be provided by request.

Who do I call if I have a concern?

If you have a more general question, we encourage you to call the Project Information Line at (855) 356-2383 or email the team at comments@HarrisonMGP.com. Kelly Henry is the community liaison working on behalf of PSE&G for the project and will be the first person to respond to your call or email.

Future Use of Site

What is the future use of the PSE&G property?

The PSE&G Site Remediation Group is not aware of any immediate plans to alter the property’s current use.

Will the remedy impact any future development on the property?

No. The remedy will not prevent future development of the Site.