TWS Remediation-2

TWS REMEDIATION

Physical and Chemical Remediation in New Jersey

Stockton University

TJ Denbleyker, Sara Chojna, William Hale

Author Note

This project was done in conjunction with Stockton University’s Remediation and Biotechnology course, ENVL 4446, taught by Dr. Tait Chirenje.

In Honor of Toni Sr.

1

Abstract

Our company’s goal is to implement optimal remediation techniques for the soil and

groundwater contamination issues specific to New Jersey. Unfortunately, Trichloroethylene

(TCE), Tetrachloroethylene (PCE), benzene, toluene, ethylbenzene, xylene (BTEX), and Methyl

tert-butyl ether (MTBE) are not only dangerous to human health but remain as the most

prevalent contaminants in New Jersey. Our remediation services are a necessity in protecting

both human health and groundwater resources from these chemicals. Due to New Jersey’s

steadily rising population redevelopment and property transfers are growing and will continue to

do so making our services a much needed commodity. Whether the project requires the

remediation of soil or groundwater from leaking underground storage tanks, dry cleaning

services, or auto body shops we have highly trained professionals who can utilize a variety of

physical and chemical remediation techniques to meet or surpass the required cleanup

standards.

2

Table of Contents

Abstract Page 1

Table of Contents Page 2

Environmental Business Prospects Page 3

Contamination in New Jersey Page 3-4

Site Characterization Pages 4-5

Physical Remediation Techniques Pages 5-9

- Excavation Page 5

- Pump and Treat Pages 5-6

- Soil Vapor Extraction and Air Sparging Pages 6-7

- Capping Pages 7-8

- Soil Washing Page 9

Chemical Remediation Techniques Pages 9-11

- Chemical Oxidation Page 10

- Critical Fluid Extraction Page 10

- Permeable Reactive Barrier Page 10-11

Conclusion Page 11

References Page 12

3

Environmental Business Prospects

The remediation field in New Jersey is experiencing a wide variety of favorable factors

that will make the longevity and success of a remediation company certain. New Jersey has a

long past of industrial and commercial environmental pollution, having nearly a century’s worth

of legacy pollution to attest to. With the extensive pollution from New Jersey’s industrialized

past creating hot spots of contamination in conjunction with land reaching an all-time premium

the work for remediation firms is bountiful and alone could constitute a reason to get into the

mix. As the economy continues to recover remediation and redevelopment projects are

substantially increasing. With New Jersey’s growing population and the limited amount of

existing land in the state, brownfield remediation projects and property transfers will continue to

grow for quite a long time. Remediation services are a necessity in protecting human health and

groundwater resources and with New Jersey’s long history of legacy pollution and its need of

redevelopment and property transfers due to population increase and limited land the time to

enter into to the remediation field has never been better.

Contamination in New Jersey

Many counties in New Jersey have contaminated soil and groundwater with a large

majority of the contamination coming from gas stations, dry cleaners, scrap metal yards, and

auto repair shops. Gas stations contain underground storage tanks (USTs) that may leak

petroleum products like benzene, toluene, ethylbenzene, and xylene (abbreviated as BTEX),

while also leaking additives like Methyl tert-butyl ether (MTBE). The contamination of such

chemicals is due to the improper maintenance or deterioration of USTs over time. In New Jersey

alone, there are currently 5,936 active UST remediation’s and an additional 1,126 known or

suspected UST sites yet to begin the remediation process (NJDEP). In addition, many gas

4

stations are also auto repair shops and spilling antifreeze and oil products, in conjunction with

other potentially hazardous materials, is a fairly common occurrence. Lead, oil, and grease can

leak when radiators are flushed but the most prevalent pollutant in New Jersey according to

Goodguide scorecard report is Trichloroethylene (TCE), a chlorinated hydrocarbon. Used as an

industrial solvent it has found use in multiple industries with its greatest use as a degreaser of

metal parts at auto body shops and metal scrap yards. TCE amongst other VOCs and SVOCs are

released accidentally or improperly and eventually find their way into surface and groundwater

and site remediation is needed to protect and preserve these essential resources. New Jersey

contains a substantial number of dry cleaning businesses, and the improper disposal of hazardous

chlorinated solvents such as TCE and PCE is common cause for the need to conduct site

remediation as both chemicals are found to be probable carcinogens and are regulated under EPA

guidelines.

Site Characterization

Often times the first and most important step in producing a proper contaminated site

remediation strategy is site characterization. The site characterization process consists of the

collection and assessment of data representing the contaminant type and the distribution of the

identified contaminants on property. To properly and adequately characterize a site the

collection of data must include the site geology, site hydrology, and site contaminants, with a

specific focus on the type, concentration, and distribution. Site characterization is typically

carried out in a multiple phase process, starting with a simple preliminary assessment called a

phase I and ending with a full, detailed site investigation that takes into account all of the factors

mentioned above. This work will be subcontracted out to the lowest bidders and based on the

5

results of the site investigation and characterization a remediation method that is most applicable

to the site will be chosen and implemented to clean the property to acceptable levels.

Physical Remediation Techniques

Excavation

One of the most simple and straightforward physical remediation techniques our

company will use is excavation. The process involves the removal of the contaminated soils with

the use of standard construction equipment such as backhoes and excavator trackhoes for either

ex situ (above-ground) treatment or disposal via a hazardous waste landfill. Excavation is a

commonly used means of remediating a site and is typically used when other in situ cleanup

methods are either too expensive or too time consuming to perform. The process is highly

effective in remediating the area as it removes the entire zone of contamination, but its usability

is largely dictated by contaminant depth and site accessibility. Excavation in general is a

relatively quick process but the time span depends greatly on the specifics of the site, with

excavation for small quantities of contaminated soil being a very cost-effective approach. The

costs of using an excavation technique to remediate a site will come from renting both heavy

machinery and a licensed operator, based on nationwide averages hourly rates range from $70-90

dollars an hour and contracts can be worked out for sites that require extended use.

Pump & Treat

Our company will also utilize a pump and treat system, a method which consists of

installing one or more wells to extract contaminated groundwater from the site. The

groundwater is pumped from the subsurface via the drilled extraction wells and transported

either directly into a treatment system or storage tanks. Pump and treat systems are a physical

means of removing contamination but will always be used in conjunction with another treatment

6

method to treat the extracted groundwater. With a large portion of New Jersey’s contaminants

consisting of VOCs including TCE and PCE the use of a Granular Activated Carbon (GAC)

system can be used. GAC systems used alongside pump and treat systems have a tremendously

high level of efficiency in treating VOCs such as BTEX, TCE and PCE amongst other synthetic

organic compounds and disinfectants at nearly 99.99% (6). The cost of purchasing a GAC

system depends entirely on the size needed, but in many cases renting a unit will be sufficient

and the pricing can be negotiated based on the the time length required. Once a system is in

place it can run with relatively little human interaction, requiring periodic monitoring and

maintenance.

Soil Vapor Extraction and Air Sparging

Soil Vapor Extraction (SVE) and Air Sparging are two physical remediation techniques

that our company will use to remediate contaminants from the subsurface soil and

groundwater. SVE involves the drilling of one or more wells into the contaminated soil,

followed by the attachment of a vacuum pump called a blower which will create a vacuum under

the subsurface. The vacuum created by the pump pulls both air and vapors through the wells

towards the surface where they are collected for treatment. This process requires a minimum

depth of at least three feet otherwise the creation of a vacuum will not be possible. In some

instances the use of a tarp to cover the surface contamination zone will be needed so as to

prevent clean air from being sucked downward, reducing efficiency and increasing the length of

time required. The collected gases are typically run through a granular activated carbon system

referred to as a GAC, where they pollutants are deposited in the activated carbon and clean air is

released back out into the atmosphere. The air sparging process begins in similar fashion, but

instead the one or more wells will act as injection ports and will be sunk directly into the ground

7

water soaked soil underneath of the water table. With the use of an air compressor air is

forcefully pumped into the ground, as the air bubbles permeate through the groundwater they

carry the contaminant vapors upwards into the soil above the water table allowing an SVE

system to be used to collect the air and contaminant vapors for treatment. Both air sparging and

SVE are useful in remediating chemicals that readily evaporate, making VOC’s perfect

contaminants for these remediation techniques. What makes these techniques so incredibly

useful is its ability to be used underneath existing buildings allowing hard to reach contaminants

to be remediated with minimal disturbance to the surface of the site. The time length required to

achieve cleanup standards depends greatly on the type and moisture content of the soil. When

soils contain high clay contents or have high moisture content vapors travel at a much slower

pace increasing the project length. SVE and air sparging are tried and proven remediation

techniques having been selected for implementation at approximately 365 registered Superfund

nationwide (7).

Capping

Capping will also be another physical remediation method that can be implemented by

our company. Capping involves the placement of a cover over top of the contaminated

soil. These covers are commonly referred to as “caps” thus the name capping is used to describe

the remediation technique. Caps do not degrade, destroy or remove soil contaminants but instead

isolate and contain them to prevent further spreading with the main goal of preventing human

and wildlife interaction with the hazardous material. The type of cap used depends greatly on

the type of contaminant and the characteristics of the site, ranging from concrete and asphalt to

use of a clay or vegetative layer. Caps work well with containing most VOC’s, SVOC’s, X-

SVOC’s, and heavy metals. Caps work moderately well with X-VOC’s, radionuclides, and other

8

inorganic compounds. Cap depth plays an important part in how effective the implemented cap

will function; the deeper the cap is placed the better it will perform as a barrier. The sediment

type the cap is placed on is another factor in its effectiveness; high silt soils have the highest

performance while granular soils with large particle sizes perform the worst. Caps can be a costly

method of remediation as the material costs are high in addition to usually having to cover a

large area to properly contain the hazardous materials. The work involved to create the cap can

be intensive but if properly installed and maintained a cap can be a highly effective tool for

treatment.

Soil Washing

Soil washing is another physical remediation technique that will be used by our

company. Soil washing is a technology that uses liquids in conjunction with a mechanical

process to scrub contaminants from polluted soil. Silt and clay particles in soil have the

tendency to bind to contaminants and in return these silt and clay particles bind to larger sand

and gravel. The soil washing process begins with the excavation and relocation of the

contaminated soils into a staging area. The soil is then fed into the soil washing equipment

where larger sized rocks and and boulders are removed. The remaining soil enters into a soil

scrubbing machine where a liquid is used, typically water but additional additives such as

detergents are possible, is mixed with the soil to cleanse away the contaminants. The wash water

is then drained away and clean water is used to rinse the soil again. The costs typically range

from $150-250 per cubic meter of soil and the equipment needed can be rented and pricing can

be worked out based on how long the heavy equipment is needed.

9

Chemical Remediation Techniques

Chemical Oxidation

The first chemical remediation technique our company will use is called in situ Hydrogen

Peroxide Remediation. This technique can be used to remove TCE, MTBE, and BTEX. For the

removal of MTBE and BTEX, a warehousing facility in Union County, NJ had used the

technique to clean the groundwater in unsorted rocks and sand. While the total cost of the

demonstration turned out to be $220K, post-treatment samples indicated that both MTBE and

BTx were below detection limits. In addition to removing BTEX and MTBE, this technique has

proven useful to remove TCE from clay backfill types of soil. One such example was at

Anniston Army Depot, Anniston, AL, where the remedial project’s area was about 2 acres with

over 43,125 cubic yards of contaminated soil. After 4 months and more than $5.7M later, soils

that were over 1,760mg/kg in TCE concentration were reduced to below detection.

Our company’s second technique, in situ chemical oxidation with Potassium Permanganate

(KMnO₄), will address contamination issues with TCE and PCE in groundwater. This technique

has been shown to be effective in many instances. One such case was on the Canadian Forces

Base Borden located in Ontario, Canada. The soil type at that location was sand. The source zone

in this area had contained an average of 1,200 mg/kg TCE and 6,700 mg/kkg PCE. While the

price for such a process was low (a mere $45K), preliminarily analysis indicated that there was a

99% reduction in peak concentration for TCE and PCE.

Critical Fluid Extraction

The third chemical remediation technique the company will use to address the

contamination of organic compounds and petroleum hydrocarbons in soil is called Critical Fluid

Extraction. Organic compounds, like TCE and PCE, have shown to be responsive to extraction

10

from soils (higher in sandy and gravelly soils than in silt) and sludges with a technique utilizing

liquefied gas. Clay-Sand soils have also shown responsive, using this technique, when extracting

petroleum hydrocarbons (7). Usually the liquified gases used are carbon dioxide, propane,

butane, or alcohol (on rare occasions). The method begins in this way: High pressure and

moderate temperatures compress the specified gases to a fluid state. Extraction begins with the

addition of hazardous waste to a vessel containing a critical fluid. Organic compounds move to

the top of the vessel, with the critical fluid, and are pumped to a different vessel. In this vessel,

the temperature and pressure are decreased causing the contaminants to volatilize from the

critical fluid. At that point, the concentrated organics are recovered while the fluid is just

recycled. While this is a higher cost remediation technique, volatile and semivolatile organics in

liquid and semi-solid wastes have been removed with 99.9 percent extraction efficiency in the

laboratory and are quite effective when implemented in the field (4).

Permeable Reactive Barriers

The fourth technique our company will use to address TCE and PCE groundwater

contamination will be passive (requiring lower operational and maintenance than pump and treat)

in situ Permeable Reactive Barriers (PRBs). PRBs remediate contaminated groundwater that

passes through a reactive zone where contaminants like TCE and PCE are either immobilized or

chemically converted to a more desirable state (8). Most applications of this use zero-valent iron

(ZVI) to treat chlorinated solvents. It is important to note that a PRB is a barrier to contaminants,

but not to groundwater flow. The technique is advantageous for site redevelopment use and the

long-term performance of such a technique as shown to be reliable.

11

Conclusion

The formation of our New Jersey based remediation company is occurring at a time

where potential business is at an all-time high. With New Jersey’s history of pollution and the

increase in redevelopment activity the need for site remediation services is steadily

increasing. Our company will offer multiple remediation techniques that will allow us to clean a

wide variety of contaminated sites. Physical remediation methods will include excavation, pump

and treat, soil vapor extraction and air sparging, capping and soil washing. In addition, our

company will utilize chemical remediation methods that include chemical oxidation, critical fluid

extraction and permeable reactive barriers. Based on the results of the site investigations an

appropriate physical or chemical remediation method will be chosen to meet cleanup standards

and achieve optimal results.

12

References

1. C.L. Ho, M.A-A. Shebl, and R.J. Watts, Development of an injection system for in situ

catalyzed peroxide remediation of contaminated soil. Hazardous Waste & Hazardous

Materials 12:15-25; 1995.

2. D.D. Gates, R.L. Siegrist, In-situ chemical oxidation of trichloroethylene using hydrogen

peroxide. Journal of Environmental Engineering. 121(9):639-44; 1994.

3. E.K. Nyer, Groundwater treatment technology 2nd ed. New York, NY: Van Nostrand

Reinhold; 1992.

4. R. Bellandi (ed), Innovative engineering technologies for hazardous waste remediation.

New York: Van Nostrand Reinhold; 1995.

5. "Drinking Water Treatment Technology Unit Cost Models and Overview of

Technologies." EPA. Environmental Protection Agency, n.d. Web. 27 Mar. 2016.

6. A Citizen's Guide to Soil Vapor Extraction and Air Sparging. Washington, D.C.: U.S.

Environmental Protection Agency, Office of Solid Waste and Emergency Response,

2001. Www.EPA.gov. Environmental Protection Agency, Sept. 2012. Web.

7. Reis, E., Lodolo, A., & Miertus, S. (2007). Interstate Technology and Regulatory

Cooperation Work Group Permeable Reactive Barriers Work Team. Retrieved March 27,

2016

8. United States, Environmental Council of the States, Interstate Technology Regulatory

Corporation. (2009, September). Regulatory Guidance for Permeable Reactive Barriers

Designed to Remediate Inorganic and Radionuclide Contamination. Retrieved March 27,

2016, from http://www.itrcweb.org/Guidance/GetDocument?documentID=67