During its years of operation, Fort Ord operated much like a small city with its own fire department, police, water supply, and garbage disposal. Garbage was disposed of in a landfill (more frequently referred as “the dump”). This landfill is located near the corner of Imjin and Abrams Roads.

Like many municipal landfills from this era, Fort Ord’s landfill was later found to be leaking hazardous chemicals into the groundwater beneath the landfill. The quantities and kinds of chemicals disposed of at the Fort Ord landfill during its operation were typical of other municipal landfills of that time, as people during that era often discarded old paint cans, cleaning solvents, and other chemicals (that we now know to be hazardous) as if they were normal household garbage.

Aerial View of the OU-2 Landfill

The Army, acting under the oversight of three federal and state regulatory agencies -- the U.S. Environmental Protection Agency, the California Department of Toxic Substances Control, and the California Regional Water Quality Control Board -- has implemented a program to clean up the contaminated water and close and cap the landfill to stop further contamination.

The Cleanup Program

The Army’s cleanup program has three elements:

1. The Army excavated one portion of the landfill (known as Cell A) on the north side of Imjin Road, and consolidated materials from that site into the larger landfill south of the road;
2. The Army put a cover over the consolidated landfill to keep all surface water (such as rainfall) from reaching the materials in the landfill, and
3. the Army built a treatment facility to treat the contaminated groundwater. The treatment plant began operating in fall 1995.

The primary way that materials in the landfill can cause contamination is for water to flow through the landfill materials, carrying any chemicals from the landfill with it as it flows into the groundwater below the site. Putting a cover over the area prevents water from reaching landfill materials. This is a standard cleanup/closure technique used to prevent future contamination.

Landfill Cover Cross Section

The cap consists of an engineered geomembrane, that is placed on top of foundation soil, and then covered with two-feet of soil. The entire area is replanted with natural vegetation.

While capping the landfill, the Army did use some soil taken from other cleanup sites as part of the foundation soil under the membrane. Soil was taken from several contaminated sites, including the beach ranges which were used during Fort Ord’s operation as small-arms (rifles and handguns) training ranges.

The Army screened the soils from the beach ranges for spent bullets, but very small particles of lead remain in the soil. Because these particles are contained under the landfill cover, water cannot reach them and the contaminants will not move out of the landfill into either the air or groundwater.

The Army put the cap over the landfill to prevent future contamination, but the Army also has to remove the groundwater contamination that has already occurred. The Army constructed a treatment facility that pumps water from wells drilled in the areas of contamination, Water from these wells is treated using granulated activated carbon. This process removes the hazardous chemicals. The water is then re-injected back into the ground. This treatment process will be continued until the quantities of contamination are below standards that are protective of human health. This process will take some years. The water in the area of contamination is not used for drinking water or for crops.

Under the terminology used in federal cleanup laws, this entire cleanup activity at the landfill is referred to as “Operable Unit 2 (OU2).”

Landfill Gas

All landfills generate gases when organic waste decomposes. This results from the action of anaerobic bacteria on the organic matter present in the waste. Landfill gas is chiefly composed of methane and carbon dioxide, with small amounts of other organic gases. While methane gas has practically no toxic effects, California regulations require that methane concentrations be less than 5% at the landfill boundary. This is because methane in certain concentrations can explode. The Environmental Protection Agency also has established standards for exposure to gases known as volatile organic compounds (VOCs).

The Army has conducted landfill gas testing and monitoring since the landfill’s closure. The Army installed monitoring devices that detect methane and volatile organic compounds.

In 2000, the Army measured concentrations of methane and other gases at the fenceline around the landfill that exceeded California and U.S. Environmental Protection Agency standards. In response, the Army installed a landfill gas extraction and treatment system adjacent to the landfill. The system sucks in methane and other gases from a series of extraction wells/pipes around the eastern edge of the landfill. These are then transported in pipes to a facility where potentially harmful compounds are removed. The gas extraction system was installed to address the methane, but it also removes other gases as an added benefit.

Subsurface Perimeter Probe Monitoring
Methane is monitored below ground with “perimeter probes” installed at the landfill boundary. To measure landfill gas, the Army installed probes at depths below the surface of the ground ranging from 12 to 32 feet, at a spacing of about one every 1,000 feet. They are installed 25 to 35 feet inside the landfill’s fence line. The Army also installed probes at the fenceline.

Air samples are also taken downwind of the landfill at five locations located between the landfill boundary and the closest residences. Air samples are taken over a 24-hour period and analyzed. Additional samples are also taken “upwind” of the landfill. These samples are referred to as the “background” samples, because they show concentrations of gases in the air that are normally in the air that are not produced by the landfill. These same gases are in the air in virtually all communities both large and small, from vehicle exhaust, industrial facilities, construction materials, household products, and natural fires.

The boundary of Cell F of the landfill is located 368 feet from the nearest house at the end of Gettysburg Court, and about 700 feet from the nearest homes on Fredricksburg Court. Residents in the student housing cannot see the landfill from the housing – except maybe from some upstairs windows – because there is a small ridge with heavy vegetation between the landfill and the student housing.

The 2002 Health Risk Assessment

In 2001, the Army conducted measurement of the gases in the air at the student housing. These tests showed that the quantities of the gases in the air in Frederick Park posed no significant health risks.

The Army conducted another round of tests in 2002. These tests showed somewhat higher readings. The Army then conducted a formal initial assessment of health risk.

In an initial assessment, researchers compare the contaminants that were measured in the air against Preliminary Remediation Goals established by the U.S. Environmental Protection Agency. The U.S. Environmental Protection Agency has determined that people are safe when exposed to contaminants at or below the amounts contained in the Preliminary Remediation Goals, even if they are exposed to these levels 24 hours a day for 30 years. If researchers find that the amount of a contaminant exceeds those goals, and are greater than the background readings (the amount of these materials already in the air from other sources), researchers conduct a risk assessment.

The Army’s researchers make some very conservative assumptions in the 2002 health assessment. Rather than using average readings of a contaminant, for example, they used the highest reading they had, even though that reading may be an abnormally high reading. Based on these assumptions, the Army found slightly elevated health risk if someone were exposed constantly (24 hours a day) for a period of 6 years. The increase in health risk was sufficiently small that it falls in the range where further study is needed, but no action is required until further investigation. The Army is now conducting a much more extensive study to measure the gases in the air.

Neither the Army nor the regulators believe there have been or are currently any harmful exposures to residents. Aside from the very conservative assumptions used in estimating health risk, some of the highest measurements were from test sites upwind of the landfill. This suggests that the source of the gases might not be the landfill, or, at least, not only the landfill. It is normal to find these gases in the air in almost all communities. In fact, even the elevated readings were still far below the background readings in a community such as Santa Barbara, which has many similarities to Monterey, and significantly below statewide averages, which include more industrialized areas.

Also, the Army did not place the cap over the final section of the landfill until Dec. 2002 – after the air measurements had been made. The agencies expect air emissions will drop now that the entire landfill is capped.

The Army will be conducting extensive tests throughout 2003 to answer the question of whether the gas concentrations are actually above EPA guidelines, and what the sources of the gases are. If action is needed, the Army will develop a program to protect the public from health risks. For example, the Army could expand the extraction system if future sampling results are elevated. Results of the Army’s studies will be posted on the Army’s web site at www.FortOrdCleanup.com and will also be posted on the CSUMB web site.

Important Links

Former Fort Ord Cleanup program website, http://www.FortOrdCleanup.com.

U.S. Environmental Protection Agency rules and guidance for cleanup of municipal landfills, http://www.epa.gov/superfund/resources/presump/landfill.htm

California Department of Toxic Substances Control Fort Ord page, http://www.dtsc.ca.gov/OMF/Fort_Ord/index.html

U.S. Environmental Protection Agency overview of Fort Ord Cleanup, http://yosemite.epa.gov/r9/sfund/overview.nsf/

Fort Ord Document Repository – CSUMB Library, http://library.csumb.edu/itcrepository

Frequently Asked Questions

What is a landfill?

A landfill is where municipalities dispose of household garbage.

What was stored in the landfill?

Landfills are used to dispose of household garbage. Unfortunately, before scientists knew they were dangerous, people used to discard items like paint cans, paint thinner, cleaning solvents, and other household products that we now describe as “hazardous materials,” as part of their household garbage. As a result, many older landfills “leak” into the groundwater beneath them, and this contamination must be removed.

Did the Army put military items like explosives, poisonous gases, or bio-medical supplies in the landfill?

No. During its operation, the landfill was used for disposal of normal household garbage and municipal waste. As the landfill was being closed, the Army used some soil taken from other cleanup sites as part of the foundation soil to support the cap, which now covers the landfill. This soil was taken from contaminated sites known as Sites 2 & 12 and from cleanup of the beaches, which were used during Fort Ord's operation as small arms (rifles and handguns) training ranges. The Army screened the soil from the beaches for spend bullets, but very small particles of lead remain in the soil. Because the contaminants are contained under the landfill cover, water cannot reach them and they will not move out of the landfill into either the air or groundwater. Explosives and live munitions were not allowed to be landfilled but it was a normal practice to dispose of inert scrap metal in a landfill. A handful of pyrotechnic items were found along with inert scrap metal from used munitions, during the excavation and relocation of landfill Cell A.

Why does a landfill produce gases?

All landfills generate gases when organic waste decomposes. This results from the action of anaerobic bacteria on the organic matter present in the waste. Landfill gas is chiefly composed of methane and carbon dioxide, with small amounts of other organic gases.

Are these gases unsafe?

These gases would be unsafe if you were exposed to very large amounts. The Army has installed underground monitoring probes and also takes air samples, to be sure the gases are at levels that are safe.

What is the Army doing to get rid of the gases?

The Army has installed a landfill gas extraction and treatment system adjacent to the landfill. The system sucks in methane and other gases from a series of extraction pipes around the perimeter of the landfill. These are then transported in pipes to a facility where potentially harmful compounds are removed.

Which homes are closest to the landfill?

The landfill is located near the Frederick Park student housing. The boundary of Cell F of the landfill is located 368 feet from the nearest house at the end of Gettysburg Court, and about 700 feet from the nearest homes on Fredricksburg Court. Residents in the student housing cannot see the landfill from the housing – except maybe from some upstairs windows – because there is a small ridge with heavy vegetation between the landfill and the student housing.

Is there a health risk from exposure to these gases?

A health risk assessment based on measurements made in 2002 showed slightly elevated health risk, but only if you had been exposed to the highest readings for six years, 24-hours a day. The amount of increased risk was small enough that it fell in a range where the U.S. Environmental Protection Agency says that further study is appropriate, but no action is required until studies are completed. The regulatory agencies have stated that they do no believe there is any significant health risk at this time.

Why do regulators think there is no significant health risk?

There are several reasons. First, the study showing elevated health risk used very conservative assumptions. For example, it used only the very highest readings, not the average readings. Many of these high readings were recorded at monitoring stations that, most of the time, were upwind of the landfill. This suggests that the readings are coming from sources other than the landfill. These same gases are in the air in virtually all communities, from vehicle exhaust, incinerators, construction materials, household products, and natural fires. In fact, even the elevated readings are significantly lower than the state average. Finally, the Army just completed capping the final section of the land in December 2002. Readings are expected to drop now that the landfill is capped. But the Army will be taking extensive readings during 2003 to be certain that health standards are not exceeded.