**5. Analysis of contamination by NJ landfills**

156 Management of Organic Waste

Total Tons Total Tons Disposed Total Disposed of In State Total Disposed of Out of State

1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003

**Year**

Pennsylvania Virginia West Virginia New York Ohio Delaware Indiana Connecticut Maryland Kentucky South Carolina Other

\*Note: Data for 1990 through 2003 was developed from information received from solid waste transfer stations and transporter monthly reports submitted to the New Jersey Department of Environmental

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003

**Year**

Fig. 2. Solid Waste Exports from New Jersey to neighboring states (in 000's of tons) (NJDEP,

The New Jersey chapter of the Solid Waste Association of North America states that about 3.6 million cubic meters of waste was disposed of in 2004 and there is a sufficient permitted

Fig. 1. New Jersey Solid Waste Trend Analysis (NJDEP, 2006)

Total

Protection

0

500

1,000

1,500

2,000

**Solid Waste Exports (103**

 **tons)**

2,500

3,000

3,500

4,000

4,500

0.0

5.0

10.0

15.0

**Amount (Million tons)**

20.0

25.0

2006)

The contamination caused by active, inactive, and closed landfills in New Jersey, particularly landfill Superfund sites, is reviewed and analyzed. All the data on the landfills were acquired from US EPA, and then input into a database with regards to geographical location, contaminant type, pollution media, current status, and remediation method.

Since there were no regulatory requirements or mandatory registration for solid waste landfilling activities until the 1970s, many New Jersey landfills were poorly sited, designed, and controlled. In addition, solid waste from neighboring states was sent to New Jersey in an uncontrolled manner. The solid waste was dumped with little or no provision for cover to prevent odor, to control birds, insects, and rodents, or to minimize long-term environmental impacts. Even though New Jersey has the strictest design and performance standards for new landfills in the nation, there are many old landfills throughout New Jersey. The legacy of past landfills not designed with stringent controls for environmental protection or closed properly remains a significant challenge facing the state (NJDEP, 2006).

Most landfills established before to the mid- 1970's lacked any leachate collection or control system, discharging the leachate directly to surface and groundwater causing serious water quality impairments. And closed landfills that do not have leachate collections systems require a costly retrofitting of a system to control discharges to surface and groundwater. Landfills, operated before the relevant environmental laws were enacted, accepted all types of waste, including industrial and commercial waste. Even after the laws were enacted, commercial and industrial waste continued to be illegally dumped at many municipal landfills. Therefore, many landfills may contain a variety of hazardous wastes. Nonetheless, municipal waste contains trace amounts of different household hazardous materials as homeowners dispose of paints, cleaning agents, solvents, and pesticides. As these hazardous materials accumulate in a landfill, a significant level of hazardous substances may result (NJDEP, 2006).

The largest anthropogenic source of methane gas emissions in New Jersey is landfills, accounting for 72% or 13.3 million tons of methane emissions. Approximately 35% or 1.9 million tons of methane emissions is released from only forty-seven landfills, both open and

Landfill Management and Remediation Practices in New Jersey, United States 159

Fig. 3. Percentages of New Jersey landfill superfund sites in terms of different contaminated

Fig. 4. Percetages of NJ landfill superfund sites where certain contaminants are found.

media

closed. These sites should use energy recovery systems to capture and use the greenhouse gas as a renewable resource. Additional revenue is obtained when the methane gas is resold or used to generate electricity (NJDEP, 2006).

New Jersey implements energy recovery facilities at several large landfills. At one landfill, revenue is generated from the electricity sales and the carbon dioxide emission credits. All suitable landfills in New Jersey, both large and small, should develop these energy-torecovery systems and assist in the funding to properly close the landfill and monitor gas emissions after closure (NJDEP, 2006).

In New Jersey, even if landfills do not receive wastes, they are not technically closed due to financial issues since final closure is expensive. All closure plans involve some degree of grading, landscaping, re-vegetation, site securing, drainage control, capping, and groundwater monitoring. Based upon historical experience in the solid and hazardous waste management program of the NJDEP, the following financial estimates are made. For a facility that requires the most limiting measures of closure may costs of up to \$180,000 per acre, while a more detailed closure involving an impermeable cap with a single synthetic geo-membrane could cost up to \$225,000 per acre. Finally, a full capping scenario of a remediation case, where substantial contamination has been identified and a 24-inch clay cap and synthetic membrane was used, the cost of closure increased up to \$ 700,000 per acre (NJDEP, 2006).

The NJDEP has more than 400 registered landfills and 200 additional sites suspected not to be registered. Before January 1, 1982, landfills were not required to submit detailed closure and post closure care plans. Therefore, out of the 400 registered landfills, 166 operated after 1982 submitting detailed plans under the "Sanitary Landfill Facility Closure and Contingency Fund Act" (Closure Act), N.J.S.A. 13:1E-100. The Closure Act places regulatory control upon closure and collects taxes on the landfills, which is reserved for final site plans (NJDEP, 2006).

Among the 146 NJ Superfund sites, namely NPL sites, 45 were, at least partially, contaminated by municipal and industrial landfill activities, of which only 10 have been completely remediated. The polluted media, in terms of occurrence frequency, are groundwater (91%), soil (62%), surface water (31%), wetlands (16%), and air (11%). A breakdown of the primary contaminated media for landfills on the Superfund list in New Jersey is shown in Figure 3. Moreover, 10s-100s of thousands of people reside within 5 km from these sites and they are located nearby natural water and public parks. Particularly, the Ringwood Mines Landfill is near a major drinking water source supplied for approximately 2 million people. Contamination of drinking water sources has been occurring but to date has been offset by improvements in detection and water treatment systems. Of the 45 NJ landfill Superfund sites, the most frequently found contaminants are volatile organic compounds such as benzene, contaminating 84% of the sites, and heavy metals like lead are found in 80% of the cases. Figure 4 shows the primary contaminants of landfills on the Superfund list in New Jersey.

Landfill leachate from the most landfills contain the common contaminants at different levels such as biochemical oxygen demand (BOD), chemical oxygen demand (COD),

closed. These sites should use energy recovery systems to capture and use the greenhouse gas as a renewable resource. Additional revenue is obtained when the methane gas is resold

New Jersey implements energy recovery facilities at several large landfills. At one landfill, revenue is generated from the electricity sales and the carbon dioxide emission credits. All suitable landfills in New Jersey, both large and small, should develop these energy-torecovery systems and assist in the funding to properly close the landfill and monitor gas

In New Jersey, even if landfills do not receive wastes, they are not technically closed due to financial issues since final closure is expensive. All closure plans involve some degree of grading, landscaping, re-vegetation, site securing, drainage control, capping, and groundwater monitoring. Based upon historical experience in the solid and hazardous waste management program of the NJDEP, the following financial estimates are made. For a facility that requires the most limiting measures of closure may costs of up to \$180,000 per acre, while a more detailed closure involving an impermeable cap with a single synthetic geo-membrane could cost up to \$225,000 per acre. Finally, a full capping scenario of a remediation case, where substantial contamination has been identified and a 24-inch clay cap and synthetic membrane was used, the cost of closure increased up to \$ 700,000 per acre

The NJDEP has more than 400 registered landfills and 200 additional sites suspected not to be registered. Before January 1, 1982, landfills were not required to submit detailed closure and post closure care plans. Therefore, out of the 400 registered landfills, 166 operated after 1982 submitting detailed plans under the "Sanitary Landfill Facility Closure and Contingency Fund Act" (Closure Act), N.J.S.A. 13:1E-100. The Closure Act places regulatory control upon closure and collects taxes on the landfills, which is reserved for final site plans

Among the 146 NJ Superfund sites, namely NPL sites, 45 were, at least partially, contaminated by municipal and industrial landfill activities, of which only 10 have been completely remediated. The polluted media, in terms of occurrence frequency, are groundwater (91%), soil (62%), surface water (31%), wetlands (16%), and air (11%). A breakdown of the primary contaminated media for landfills on the Superfund list in New Jersey is shown in Figure 3. Moreover, 10s-100s of thousands of people reside within 5 km from these sites and they are located nearby natural water and public parks. Particularly, the Ringwood Mines Landfill is near a major drinking water source supplied for approximately 2 million people. Contamination of drinking water sources has been occurring but to date has been offset by improvements in detection and water treatment systems. Of the 45 NJ landfill Superfund sites, the most frequently found contaminants are volatile organic compounds such as benzene, contaminating 84% of the sites, and heavy metals like lead are found in 80% of the cases. Figure 4 shows the primary contaminants of landfills on the

Landfill leachate from the most landfills contain the common contaminants at different levels such as biochemical oxygen demand (BOD), chemical oxygen demand (COD),

or used to generate electricity (NJDEP, 2006).

emissions after closure (NJDEP, 2006).

(NJDEP, 2006).

(NJDEP, 2006).

Superfund list in New Jersey.

Fig. 3. Percentages of New Jersey landfill superfund sites in terms of different contaminated media

Fig. 4. Percetages of NJ landfill superfund sites where certain contaminants are found.

Landfill Management and Remediation Practices in New Jersey, United States 161

ammonia, heavy metals, and chlorinated hydrocarbons. However, due to old landfills accepting all types of waste and illegal dumping, the leachate from these landfills may contain uncommon pollutants (e.g. PCBs) derived from hazardous substances such astar, paint sludge, waste oils, drummed industrial waste, and medical waste. These old landfills with mixed solid wastes are usually the ones considered for redevelopment, which poses

New Jersey landfills listed on the Known Contaminated Site List and the National Priority List are shown in Figure 5. It would be noted that the known contaminated sites include all sites on the National Priorities List (Superfund sites) and other contaminated sites (e.g. brownfields). The majority of the landfills are concentrated the areas of New Jersey close to New York City and Philadelphia area, with a band connecting the two areas in central New Jersey. The counties with the most landfills are Atlantic, Middelsex, and Morris, with 9, 7, and 6 landfills, respectively, most likely as a result of high population density, urbanization,

The frequently used remediation methods for landfills on the National Priority List in New Jersey include excavation to recover recyclable material, capping to reduce leachate generation, air sparging and soil vapor extraction to capture and remediate gases, and

Since siting new landfills is a lengthy, expensive endeavor and the community raises opposition to landfills nearby, New Jersey may not have suitable areas for a new landfill. Additionally, existing, operating landfills cannot adequately expand new cells. Therefore, the Statewide Waste Management Plan promotes the use of "sustainable landfills" implementing innovative technologies to extend the lifetime of the landfills. In addition to the methods mentioned above, New Jersey is researching alternative daily covers, deterring

Landfill mining consists of excavating and the subsequent processing of landfilled wasted. This procedure recovers recycled materials, cover soil, and a combustible fraction to free landfill space. The excavation techniques for landfill mining have not changed since the 1950's and resembles surface mining. The excavated mass is processed through a series of screens for sorting. The amount recovered depends heavily on the physical and chemical properties of the waste, types of mining technologies used, and the efficiencies of the

However, if the separated materials are contaminated or have a poor quality, the viability of recovering recyclable items from old landfills in New Jersey is reduced. Landfill mining would be most advantageous when the waste is fully decomposed and stabilized such as

Capping a landfill involves three layers: an upper vegetative (topsoil) layer, a drainage layer, and a low permeability layer made of a synthetic material covering two feet of

after either aerobic or anaerobic bioreactor (NJDEP, 2006).

bulky wastes, landfill surcharging, and redevelopment opportunities (NJDEP, 2006).

many problems with remediation (Wiley and Assadi, 2002).

and industrialization.

**6. Remediation methods** 

pump-and-treat the leachate plume .

**6.1 Excavation/ landfill mining** 

applied technologies

**6.2 Landfill caps** 

Fig. 5. New Jersey Landfills listed on the Known Contaminated Site List and the National Priority List

ammonia, heavy metals, and chlorinated hydrocarbons. However, due to old landfills accepting all types of waste and illegal dumping, the leachate from these landfills may contain uncommon pollutants (e.g. PCBs) derived from hazardous substances such astar, paint sludge, waste oils, drummed industrial waste, and medical waste. These old landfills with mixed solid wastes are usually the ones considered for redevelopment, which poses many problems with remediation (Wiley and Assadi, 2002).

New Jersey landfills listed on the Known Contaminated Site List and the National Priority List are shown in Figure 5. It would be noted that the known contaminated sites include all sites on the National Priorities List (Superfund sites) and other contaminated sites (e.g. brownfields). The majority of the landfills are concentrated the areas of New Jersey close to New York City and Philadelphia area, with a band connecting the two areas in central New Jersey. The counties with the most landfills are Atlantic, Middelsex, and Morris, with 9, 7, and 6 landfills, respectively, most likely as a result of high population density, urbanization, and industrialization.
