Wednesday, February 21, 2007

 

Landfill fire expert Todd Thalhamer's report to the EPA

The Canton Repository

Director Chris Korleski (Chris),

As you and your staff requested, I would like to take this opportunity to provide you with my preliminary opinions and recommendations for the incident at Countywide RDF (CRDF). I understand you have a decision to formulate concerning the site issues by February 21, 2007. Should you desire a report of my findings and opinions I request you contact my agency in writing so I may account for the work time to develop the report.

During the past two weeks I have attempted to collect data to examine the “heating event” at CRDF. Your staff and Countywide RDF staff have gone beyond my expectations is assisting. Countywide RDF was able to sample and collect carbon monoxide and temperatures within seven days of the initial request. An immense effort both in time and money has been put forth to understand the complexity of this reaction. While more data collection is necessary to indicate a trend for the reaction occurring at the landfill, verify my conclusions, clarify a few data anomalies, and adequately characterize the landfill gas composition, I have been able to develop my opinion on this incident.

With all the recent correspondence from Countywide Recycling and Disposal Facility, Cornerstone Environmental Group, LLC., SCS Engineers, US EPA, internal memos, gas data logs, graphs and charts, and various professional papers, and fire behavior and investigation text books, I have developed an opinion concerning this event. Let me summarize the facts concerning the “heating event” at CRDF that I am aware of to date:

The current event began sometime prior to December 2005;

A reaction is occurring in the aluminum dross and is producing heat and hydrogen gas;

A reaction is occurring between layers of aluminum dross and waste from the recirculation of leachate;

CRDF is experiencing temperatures outside the normal operating range of a permitted solid waste landfill;

A number of gas collection wells at CRDF are not in compliance with the US EPA’s New Source Performance Standards (NSPS) maximum temperature of 131 degrees Fahrenheit (F)

The highest reported temperature was 353 °F degree and recent temperature survey indicated the highest recorded temperature was 214 °F;

An event is producing carbon monoxide (CO) at CRDF;

The CO is not coming from the reaction of the aluminum dross

Detectable CO (i.e., greater than 1,000 ppmv) levels in the landfill were reported in February, April, July, August of 2006 and recently in February 2007;

One of the highest carbon monoxide levels was detected in February 2006 at 8067 ppmv in gas well W43R, and the recent CO data indicates the CO has leveled off. (Note: CO may be decreasing); and

CRDF is experiencing remarkable settlement (e.g. over 30 feet in less than a year) in the area of the “heat event.”

I could debate the issues I professionally disagree with in the some of the referenced documents, however, I will just provide my opinions and recommendations for the event.

Opinion on CRDF

Based on my review of the information available to date, Countywide has experienced and is currently experiencing a subsurface event outside the normal decomposition cycles of a landfill. This event has the potential to damage the engineered component unless certain steps are put in place. Past CO level, gas extraction temperatures, methane production, and infrared analysis indicate this event has grown in size and is continuing. I believe the event at this time has leveled off and may be decreasing depending on additional CO and temperature surveys. Professionally I do not believe anyone can fully understand the entire event at CRDF due to its complexities, but this is why I will recommend at number of professionals examine certain matters.

Opinion on the “Heating or Pyrolysis Event”

After reviewing the available data and information, I believe Countywide CRDF is currently experiencing two types of fires. Neither type of these fires is the characteristic underground fire documented in the literature or as seen in the field; however, the latter is the first stage of a characteristic underground fire. Countywide is experiencing a classic metal fire and smoldering fire.

The fact a reaction has occurred in the aluminum dross and bag house dust waste, and that the reaction is and has produced significant quantities of hydrogen gas with heat above 200 F by definition is a self-sustaining metal fire. This metal fire (aka “heating event”) has caused a second fire in the municipal waste. This second fire is a smoldering fire. So what is the difference? Temperature is the difference in this assessment. As stated by CRDF and its consultants, which I agree with, you would typically have a thermal runaway in the waste by now and probably have destroyed a number of gas collection wells. However, this is not the case. To date, I have not seen or heard any evidence of damage to the engineering controls except for the damage to the cover from settlement. With that said, I believe Ohio EPA will need to establish a more stringent temperature survey program to verify the site conditions and monitor the smoldering fire.

The most fundamental fire observation is that the landfill is producing CO. Until it can be reasonably explained why, where, or how the CO is being produced, I will opine that the carbon monoxide is being produce from incomplete combustion. This incomplete combustion is part of the pyrolysis of organic waste at temperatures over 170 °F. The only scientific reason I know this to occur is in an oxygen deficient atmosphere by a smoldering fire. I would like to point out again that this is not an underground fire that I have previously defined. While this is a fire in itself, this is the first stage of an underground. A smoldering fire does not have the energy or temperature required to melt engineered controls. Additionally I need to note that the smoldering fire is producing CO at levels in the wells that are Immediately Dangerous to Life or Health. While I do not expect anyone to be exposed to these levels of CO while working on the facility, I also recommend below one change to the site operations at Countywide RDF.

I believe the metal fire started sometime around November 2005 and caused the smoldering event to occur as early as February 2006 based on data supplied by CRDF. I also conclude from the July and August 2006 CO analysis that the smoldering event had expanded.

Additionally I am surmising that the majority of the odor complaints and settlement occurred after March or April 2006 when the smoldering event expanded and produced many compounds of incomplete combustion that in turn combined with free hydrogen from the aluminum dross to produce the unusual odors. These odors were then driven from the landfill by the pressure deferential produced by metal fire and resulting hydrogen gas.

Also, I have examined the volatile organic compounds (VOCs) list from a June 2006 sample under the tarp. While I typically use CO to determine if a landfill fire and now a smoldering fire exists, there are other indicators. I primarily use CO testing because the tests are inexpensive and landfill gas literature and industry recognizes CO is not a part of the normal landfill decomposition cycle. I also have been able to look at compounds like benzene, acetonitrile, vinyl acetate, and xylenes. The reason benzene is important at this stage of the event is that benzene is produced from melting (i.e., pyrolysis) plastics around 250 °F. The data supports my theory that the landfill is only undergoing a smoldering fire (Temperatures less than 250-275 °F) and not an underground landfill fire (Temperatures well over 450 °F) , however, this data set for the landfill gas is incomplete. I was only able to find VOC analysis in Ohio EPA data set and was not able to compare other known compounds. I will also recommend to Ohio EPA perform a complete gas analysis for VOCs, Semi-VOCs, and Polycyclic aromatic hydrocarbons (PAHs), etc.

This is my profession opinion of the events at Countywide. This opinion is provided with the understanding that my comprehension of the event is as principled as the data supplied.

Recommendations

Fire Issues: Recommend Ohio EPA request CRDF to activity develop a suppression plan that includes examining injection technologies and expanding a cover system for the 88 acres. I recommend Ohio EPA allow CRDF to start the injection of the 25% solution of magnesium chloride in two wells to demonstrate the effectiveness of the injection. This process should be closely examined with real-time gas analysis with set stop points. Also, I recommend CRDF examine in the laboratory environment the possibility of the application of other specialty foams capable of extinguishment through heat encapsulation or other methods. I can provide a list if necessary.

I consider the smoldering fire to be extinguished when the CO levels fall below 100 ppmv and under control when 95% of the gas extraction wells are under 1000 ppmv. I consider the metal fire to be extinguished when landfill temperatures are below 131 °F and under control when 95% of the gas extraction wells temperatures are under 170 °F. Hydrogen gas guidance for the metal fire may be used if a protocol can be developed.

Slope Stability: Strongly recommend Ohio EPA hire a independent third party consultant to examine the structural integrity of the landfill. While the landfill has examined this issue with its consultants and has determined the facility is stable, I believe a third party review is warranted given the rapid rate of settlement (i.e., over 30 vertical feet) over the past year. Stability and heating issues are traditionally the only issues that cause significant events.

Landfill Engineered Components: Ohio EPA should request the landfill provide their methodology in determining the integrity of the engineered components (i.e., liner, leachate recovery, etc.) and verify the data. The landfill may want to examine the possibility of placing a camera and thermocouple down the leachate collection system to verify the condition.

Aerial Infrared Imagery: While there are some conflicts with the December 2006 infrared and gas well log data, I believe Ohio EPA should investigate the possibility of surveying this facility again as well as two to three others to compare the infrared results. The Ohio State Patrol did indicate two small irregularity (both under 10,000 sq ft) on the northwest corner of Cell #5c; however, the site conditions did not support the infrared results (i.e., snow was present on the slope where the infrared indicated heat). Additional results may provide Ohio EPA with the ability to indicate the problem is not advancing.

Health Impacts: Recommend Ohio EPA request all employees working or sampling on the gas collection system wear at a minimum real time carbon monoxide samplers, preferably a personal four gas meter (i.e., CO, H2, O2, % Gas). These CO meters can be the disposable kind that will not need calibration. Please check the cross sensitivity of the CO Sensor to hydrogen gas.

Groundwater monitoring: Recommend Ohio EPA compile the groundwater monitoring data and establish background results for the public. Also, Ohio EPA may want to perform their own quarterly groundwater monitoring along with the landfill to provide additional safe guards for the community. I do not expect any issues based on the past groundwater monitoring; however, it would demonstrate to the community at large that Ohio EPA is verifying the groundwater monitoring system.

Emergency Response Plan for a Catastrophic Event: Given I do not anticipate a catastrophic event occurring, I suggest the landfill and Ohio EPA provide a joint document briefly addressing the evacuation routes, shelter locations, necessary response resources and other issue under the community right to know.

Incident History: Request the landfill develop an incident history to provide lessons learned for the industry. Ohio EPA may also want to request a technical discussion with the landfill to examine the fill sequence of the aluminum dross and when and where the leachate recirculation was activated.

Data Issues: Recommend that Ohio EPA continue to collect independent data, similar to the CO sampling and temperature data, along with the landfill to assure the public the data collection process is valid. Additionally, recommend Ohio EPA require temperature and CO program to verify the site conditions and monitor the smoldering fire.

Gas Collection Data: Ohio EPA should request the landfill reduce the allowable oxygen in an interior gas extraction well from 5% by volume to 1.5% by volume and nitrogen from 20% to 12%. Although this request is more stringent than the federal regulations (i.e., NSPA) allow, the landfill needs to reduce the amount of oxygen/nitrogen available inside the waste cell. California environmental code requires the oxygen levels below 1.5 % and a nitrogen levels below 12% in an interior well. I believe this requirement is based on sound engineering principles. Also, Ohio EPA needs to communicate to the landfill that they should repair well boot and cover membranes as soon as feasible to reduce the infiltration of oxygen. One note of caution with this request, it is typical in the landfill industry to reduce the amount of vacuum on an interior well to meet the 1.5%/12% requirement or goal. However, with the odor issue I am not recommending the reduction of vacuum to meet the 1.5%/12% goal. I am suggesting the landfill place additional soil and/or membrane or repair the collection system to allow for the continued extraction and odor abetment while complying with the 1.5%/12% goal.

Gas Extraction StandardOxygen Level Nitrogen Level
NSPS5%20%
California Standard1.5%12%

Also Ohio EPA should request CRDF complete full characterization of the landfill gas to establish the compound present.

Task Force: Ohio EPA may want to consider establishing a working task force to oversee the landfill operation and investigation for the next year. This task force would have primary responsibility for oversight and be composed of local, state and federal representatives. This task force would regularly meet with the landfill and public interest groups to ensure communication channels are open.

Should you or your staff like to discuss this fire issue further or other operational landfill issues over the holiday weekend I will make myself available.

Regards,

Todd Thalhamer, P.E.