Bridgeton Landfill stops accepting waste of any kind. The site begins implementing closure activities, in coordination with the Missouri Department of Natural Resources.
Republic Services acquires companies as part of a larger transaction involving assets around the country, including Bridgeton Landfill, LLC.
The Landfill's monitoring contractor detected high levels of carbon monoxide in a large group of gas extraction wells, leading to the discovery of a heat-producing reaction deep within the site.
Within 24 hours, Landfill operators notify State regulators and St. Louis County officials, sharing and analyzing data as well as establishing emergency contact protocols. Operators also adjust the flow of gas in the affected wells.
Landfill operators implement odor-management plan with daily odor control logs and temperature monitoring. They also begin procuring odor-control equipment. Operators meet with Missouri Department of Natural Resources personnel, brief local first responders, and begin coordination with health and safety contacts at neighboring businesses.
Landfill operators install a High-Density-Polyethylene liner on known odor locations, as well as piping beneath the liner to manage liquid and gas accumulation. Operators install 18 new monitoring points, and work on a gas interceptor trench along the western slope of the South Quarry. Data indicates that the reaction is stabilized, and there are few complaints of off-site odor.
Continued surface settlement causes gas lines to sag, restricting normal flow. Leachate collection systems are also affected. Both factors increase odors. Landfill operators advise the community that necessary repairs will produce more odor in the coming weeks. Operators use an odor-neutralizing turbine to mitigate odors during repairs. They submit the first contingency plan to State regulators on the subsurface reaction.
Landfill operators commit additional resources to manage the reaction, including expert personnel and enhanced systems to collect and destroy odor-causing gas. The new personnel will form a team of 14 full-time environmental professionals — one of the most capable landfill management teams anywhere. They will lead dozens of engineers, technicians and consultants at the site.
Comprehensive air sampling event concludes that the odors, while unpleasant, do not pose a risk to public health or safety. The Landfill team begins installing additional gas extraction wells and temperature monitoring probes, makes upgrades to leachate conveyance piping and continues work on a gas and leachate collection trench.
The subsurface reaction increases surface settlement. Landfill operators make extensive repairs to areas in the South Quarry affected by surface settlement. Operators install new piping and more durable wellheads. This work requires temporarily shutting down the gas collection system, which has a corresponding effect on odors.
Missouri Department of Natural Resources (MDNR) begins air monitoring twice daily at 13 predetermined testing points around the Landfill’s perimeter, using stationary AreaRAE monitors and handheld devices. MDNR also conducts weekly 4-hour sampling events at two upwind and two downwind locations beyond the Landfill’s boundary. Data is evaluated on a weekly basis by the Missouri Department of Health and Senior Services.
The Landfill team installs 40 new gas extraction and interceptor wells to collect, control and destroy odor-causing gas. They add more temperature monitoring probes in strategic locations to monitor the movement of the reaction. They also make upgrades to the flare system and begin work on a synthetic liner that will eventually cover 46 acres of the South Quarry and a portion of the North Quarry.
The Landfill team enters into an Agreed Order with the State of Missouri where the Landfill commits to additional monitoring, reporting and contingency planning. In addition, it requires the Landfill team to submit detailed information to the public on a weekly and monthly basis.
The Landfill team also offers temporary relocation assistance to approximately 270 nearby households in response to community concerns about potential odors during three weeks of scheduled repair work. The team completes the repairs within six days.
The Landfill team installs an Ethylene Vinyl Alcohol (EVOH) synthetic liner over the South Quarry. The liner consists of two layers of High-Density Polyethylene with a layer of EVOH in the middle, and is capable of preventing build-up of gas and moisture under the liner. The liner covers 42 acres and helps to manage the reaction and corresponding odors, as well as enabling more efficient gas collection.
Polar Vortex brings record cold to St. Louis. Temperatures drop to 12 degrees below. Three of four flares go down, leading to odor alerts. The team makes repairs in blistering winds, uses a heated tent to accommodate tanker trucks, and thermal blankets and kerosene heaters to protect working infrastructure. The team presses ahead with construction at the leachate pretreatment plant, one of a few active construction sites in greater St. Louis.
The team agrees to expanded carbon monoxide monitoring, confirming that the reaction has not impacted the Landfill's North Quarry.
A small surface fire, unrelated to the reaction, occurs and is quickly extinguished by team members. This incident leads to closer working relationships with local first responders, and will soon result in a revised, comprehensive Incident Management Plan.
Landfill team announces new real-time odor monitoring capabilities, enabling a more prompt response to community concerns submitted through the MDNR web site. The new capabilities allow the community to provide information on date, time, location and strength of odors. Three-out-of-four complaints submitted are determined to originate from non-landfill sources.
Data from the third round of additional Carbon Monoxide testing confirms that the North Quarry has not been impacted by the subsurface reaction occurring in the South Quarry. The North Quarry is the area closest in proximity to the radiological materials in the adjacent West Lake Landfill. The results from three additional rounds of CO testing indicate healthy well conditions in the North Quarry.
The Circuit Court of St. Louis County accepts the Second Amendment to the First Agreed Order between the State of Missouri and Bridgeton Landfill. The Amendment affirms the substantial site improvements made in the past year and it establishes an updated monitoring plan and additional odor control measures to be developed in coordination with the Missouri Department of Natural Resources.
The Landfill team announces an updated, comprehensive Incident Management Plan that incorporates feedback from local first responders and regulatory agencies after multiple coordination meetings in recent months. The plan enhances safety measures at the site by establishing roles and responsibilities for a coordinate response to an incident. It also simplifies incident classification systems and expands upon the list of available on-site resources.
Landfill team notifies state officials that the first of four, 1-million gallon tanks supporting the leachate pretreatment plant is operational. It represents a $40 million infrastructure investment that under normal circumstances can take four years to complete. The team will complete construction within approximately 18 months.
The Landfill team completes ahead of schedule odor reduction milestones set by the Circuit Court of St. Louis County in the Second Amendment to the First Order with the State of Missouri. Milestones include removing 30 temporary liquid treatment tanks and submitting a work plan for an upcoming odor reduction pilot study.
The U.S. District Court for the Eastern District of Missouri approves a final settlement that brings closure and fair compensation to 76 percent of Landfill neighbors for any loss of use or enjoyment of property as a result of odors emanating from the site. The final settlement amount totaled nearly $4.8 million.
The team implements ahead of schedule an Odor Management Plan with detailed protocols for identifying, investigating and remediating actual odor occurrences. They begin a pilot study on an odor filtration process using woodchips to neutralize odor-causing elements within landfill gas. They also begin a fifth round of air quality sampling that will be measured against 2012 and 2013 data.
Although all available evidence confirms that the reaction occurring in a portion of the Landfill’s South Quarry has not impacted the adjacent North Quarry, the Landfill team agrees to State requests to conduct a fifth Carbon Monoxide sampling event. This includes analysis of wells in the North Quarry, and similar testing in a series of Gas Interceptor Wells located in strategic positions across the site. The resulting data, which was publicly available by late October 2014, verifies once again that the reaction is not impacting the North Quarry.
The team also begins a pilot program to evaluate the potential for extracting heat from the Landfill’s subsurface, using closed-loop cooling lines. In addition, the Landfill team installs a new pilot odor-control system along the Landfill’s southern fence line, which uses a vaporizing system designed to seek out, attach to and neutralize faster and lighter odor-causing molecules.
The highly advanced leachate pretreatment plant — built by the Landfill team in less than one third the normal construction time for a project of that magnitude — begins 24/7 operations, and is approved by the St. Louis Metropolitan Sewer District. Their approval allows the Landfill team to resume its longstanding practice of discharging wastewater directly to the District through an on-site connection, instead of trucking the wastewater from the site on local roads. This saves hundreds of truck trips on local roads each month.
The Landfill team completes a project to install 36 new or replacement Gas Extraction Wells in the South Quarry, further improving the Landfill’s systems for collecting and controlling odor-causing gas. The team also performs the latest in a series of comprehensive air sampling events, analyzing landfill gas and ambient air around the Landfill for more than 200 constituents or compounds, and produces summary data from its previous comprehensive air sampling conducted in July 2014. The data from the July sampling shows that upgrades to the Landfill’s infrastructure have succeeded in reducing various constituents in landfill gas, and verifies that the constituents responsible for any odors at the site do not pose a public-health concern.
The Landfill team installs an additional nine temperature-monitoring probes in the North Quarry, and five additional probes in the South Quarry and “neck” area between the two Quarries. Results from the probes are added to the voluminous data compilations produced to the public and regulatory agencies on a weekly basis, providing further verification that the reaction occurring in a portion of the South Quarry has not impacted the North Quarry.
The Landfill team completes construction on a new, 7.2-mile sewer-line extension to connect the site directly to MSD’s Bissell Point facility. The project provides even more flexibility for MSD when deciding where to route pretreated wastewater for final treatment. The extension project is funded entirely by the Landfill, with construction work performed by an area contractor involving local labor.
The State of Missouri approves the Landfill team’s proposal to expand of an innovative heat extraction pilot program at five additional gas interceptor wells in the South Quarry. The pilot program tests a promising, proprietary technology involving a closed-loop system that continually circulates temperature-treated liquid at select gas interceptor wells.
The Missouri Department of Health & Senior Services releases results from the latest Comprehensive Air Sampling Event, conducted in January of 2016, confirming that air conditions at the Landfill do not pose a public health concern.
An extensive scientific study of landfill gas constituents destroyed by the Landfill’s flare system confirms that air conditions at or in the vicinity of the site do not pose a public health concern. The study also concludes that any constituents of concern in landfill gas destroyed at the site’s flare system continue to decline, which is another indication that the site is in a managed state.
The Landfill team conducts the fifth in a series of Comprehensive Air Sampling events at the site since 2012, testing for more than 170 constituents in ambient air on the Landfill property, upwind and downwind from the site, and in gas extracted from the Landfill’s subsurface. All such studies to date have confirmed that any constituents detected in air at the site do not pose a public-health threat and are well below health-based screening levels.
In sworn deposition testimony, Dr. Tony Sperling, the lead expert for the Missouri Attorney General’s Office testifies that the subsurface reaction occurring at Bridgeton Landfill: (a) is not a fire; (b) is confined to the Landfill’s South Quarry; and (c) is not in the Landfill’s North Quarry or close to the radiologic material at the adjacent West Lake Landfill OU-1. Dr. Sperling testifies that it is “physically impossible” for the reaction to ever enter the Landfill’s North Quarry, as long as existing water levels in the North Quarry are not reduced.
The Centers for Disease Control and Prevention’s Agency for Toxic Substances Disease Registry releases a health consultation, concluding: that any levels of radioactive substances in groundwater in off-site wells “are below the regulatory limits for drinking water;” that “there is no evidence that radon produced in the landfill will migrate to residential areas;” and that “there is no evidence of contamination along roads leading to the landfill property.”
The Landfill team announces new data that shows continued, favorable trends over a two year span in wellhead temperatures. The data provides further confirmation that the Landfill is in a managed state.
The Missouri Department of Natural Resources releases results from samples of stormwater flowing along the boundary of the adjacent West Lake Landfill, taken in December of 2015. The testing detected no constituents above levels of public health concern, even applying stringent drinking water standards.
The Landfill team announces plans to install 16 additional cooling points in the “Neck” area, located between the North and South Quarries. The innnovative, proprietary technology has demonstrated promising results in extracting heat from the subsurface at 12 locations in the Neck area to date.
The Landfill team conducts a major expansion of the site’s heat extraction system. The proprietary technology circulates temperature-treated water through a closed-loop line, extracting heat as it travels. Warmer water is returned to a chiller for re-cooling and re-circulation. The points are at various depths, up to 180 feet beneath surface level. The system was first introduced as a pilot program in the fall of 2013 and expanded in June 2015 due to early successes. The team worked in conjunction with U.S. EPA on the project. This expansion more than doubles the system.
The Landfill team implements sulfur dioxide (SO2) ambient air monitories in the vicinity of the site. The monitors are placed in collaboration with the U.S. EPA and provide real time air monitoring. Data from the devices is made available to the public in real time on the Landfill’s website. The data provide further assurance that air conditions at and near the Landfill do not pose a risk to public health.
An agreement is reached in 34 lawsuits brought on behalf of individual households in the vicinity of the Landfill. The suits were pending in the U.S. District Court for the Eastern District of Missouri. Concluding the cases brings further closure with Landfill neighbors, the majority of whom reached a settlement with the Landfill in August, 2014.
The Landfill’s heat extraction system is more than doubled by installation of 16 additional cooling points in the neck area between the North and South Quarries. With the addition, the total number of cooling points is 28. Thanks to the system, subsurface temperatures have been reduced by as much as 50% in nearby temperature monitoring locations.
19 additional temperature monitoring probes are installed in and adjacent to the North Quarry. There are now approximately 50 such probes in strategic locations throughout the Landfill. The probes are engineered to operate at a range of depths, from 20 to over 150 feet below surface level. The site team collaborated with U.S. EPA on the installation. Data from the probes are made available to regulators and the public in weekly and monthly reports. The new probes complement existing comprehensive capabilities at the Landfill and provide even more data and greater redundancies.
Recent site data shows slowing surface level settlement rates in the South Quarry. This provides further confirmation that the subsurface reaction remains isolated in the South Quarry. Data released in March 2017 show a South Quarry surface settlement rate of 0.74 feet. By comparison, one year earlier settlement was nearly double at 1.35 feet. Two years prior, the settlement rate was 1.75 feet over the same period. The data is made available to regulators and the public via weekly and monthly reports.
The Landfill team begins work to expand the Ethylene Vinyl Alcohol (EVOH) geomembrane cover. The project will install additional liner over the North Quarry and add to the existing 46-acres of cover already in place. The EVOH cover is part of the site’s proactive odor control system and another site enhancement. Contractors and local labor participate in the installation.
An expert review of stormwater samples collected by MDNR shows stormwater runoff from the Bridgeton Landfill is safe. Samples were collected in April, 2017 during an extreme rain event. A leading expert conducted a technical review of MDNR’s data and analyzed a split sample of the stormwater collection. The report concludes the Landfill’s stormwater runoff is safe.
An MDNR report concludes radioactivity found in the stormwater samples collected in April, 2017 did not originate from the West Lake Landfill or the Bridgeton Landfill. The agency’s report provides further evidence that the site does not present a public health risk.
The West Lake Landfill Potentially Responsible Party (PRP) group responds to EPA comments on draft plans for the adjacent West Lake Landfill. The responses represent another milestone toward reaching a final, scientifically-based remediation decision for the adjacent Superfund site. They also provide further confirmation that the site is safe and in a managed state.
The Landfill team submits a Heat Extraction Barrier One-Year Report to State regulators. Data in the report show that over 2.7 billion BTUs of subsurface heat have been extracted since the system was expanded the previous year. The Report also demonstrates that the heat extraction barrier is successfully reducing temperatures in nearby subsurface temperature monitoring probes, effectively creating a 40 foot wide subsurface barrier in the “Neck” area between the Landfill’s North and South Quarries.
After 16 months of data compilation from two sulfur dioxide monitoring locations near the site, the data confirm that sulfur dioxide emissions from the Landfill have consistently been below the EPA’s National Ambient Air Quality Standards. There has not been a single elevated reading to date that exceeds the Standards.