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Ask Nelson
Ask Nelson
Our 30+ years of experience is now with you any time of day, anywhere in the world, with Ask Nelson.
In another Nelson innovation, we’ve turned more than three decades of environmental remediation knowledge and experience into an AI team member you can take into the field or use from the office.
It is a custom-trained environmental remediation agent, built around Nelson’s technical knowledge, project experience and capabilities, rather than a general-purpose assistant.
Ask a straightforward question and get a straightforward answer. Turn on Deep Dive when you want more technical detail. You can also give Nelson images, drawings and schematics to help provide context for your questions.
And when your question needs a human, just ask. Nelson can connect you with a member of our team.
30+ years of Nelson experience. Now available whenever you need it.
Start with your own document
Nelson reads the document, pulls out the contaminants, tonnage and jurisdiction, and matches it against the treatment paths that fit. You see the extracted text before anything is analysed, and you can correct it.
These are the questions that come up most often, with the short version of each answer. Open the chat for the version that fits your site.
Start with the petroleum product, TPH analytical methods and ranges, relevant BTEX and PAHs, co-contaminants, soil moisture and sample locations. Cleanup objectives and groundwater or vapor pathways also matter. Nelson's US petroleum-soil guide connects those inputs to site-specific treatment selection and verification, with Tioga as a documented project reference.
US petroleum soil treatment guide
The Tesoro Tioga pipeline spill in Mountrail County, North Dakota. Nelson moved 2.4 million tons of soil and thermally treated 1.2 million tons of Bakken-crude-impacted soil, one of the largest onshore oil spills in continental US history, with zero soil sent to landfill.
Nelson provides treatment and disposal options. The appropriate approach depends on the contaminants, material properties, site access, regulatory requirements and approved receiving facilities. Characterization and project requirements guide the selection, and any reuse of treated material requires verification and regulatory acceptance.
Preparing a remediation inquiry
Confirm the applicable waste determination, receiving-facility acceptance, analytical profile and transport documentation before soil moves. Keep excavation units and stockpiles traceable, and assign responsibility for residuals and rejected loads. Treatment and permitted disposal can serve different streams within the same project; the full material profile determines the appropriate route.
US contaminated soil management guide
Mobilisation depends on permits, site preparation and distance more than on equipment availability. The mobile fleet is designed to travel, and Nelson has set up on five continents including Arctic sites and a Pacific island tank farm. The realistic path is a site assessment first, then a schedule built around the permitting authority's clock.
Contaminant type and concentration, estimated tonnage, soil moisture and texture, the closure standard being targeted, site access and power, and the schedule you are working to. Analytical data from the site investigation moves the conversation fastest. Ask Nelson can work through the list with you before anyone picks up the phone.
A Phase II assessment measures what a Phase I review flagged: which contaminants are present, at what concentrations and across what extent. Those findings set the criteria comparison, the affected volumes and the treatment options a remediation plan can be built on.
Assessment establishes what is present, the intended land use sets the criteria, and treatment, disposal or risk management bring the property to them. Closure documentation is what lenders, buyers and regulators rely on, so it belongs in the scope from the start.
Compare proposals using the same quantities, scope boundaries, material conditions and verification requirements. Clarify inclusions, exclusions, assumptions and responsibilities before comparing totals.
A laydown area for the plant and stockpiles, all-weather access for haul trucks, power or fuel supply, water, and a sampling area that keeps treated batches separate from untreated feed. Confirming those five items early prevents most of the schedule slippage that shows up after mobilisation.
PFAS can be destroyed. Breaking the carbon-fluorine bond takes sustained high temperature with controlled residence time and full off-gas treatment. Granular activated carbon, ion exchange and foam fractionation concentrate PFAS into a smaller waste stream that still has to go somewhere. Concentration is a useful first step. Destruction is what closes the liability.
In the United States the EPA set enforceable drinking water limits in 2024 at 4 parts per trillion for PFOA and PFOS, with hazard-index limits for several others. Soil and groundwater screening levels are set state by state. In Canada the Health Canada objective is 30 ng/L for the sum of 25 PFAS, with provincial guidance layered on top.
PFAS rules by state and province
Yes. NATO selected Nelson's mobile thermal technology for a PFAS destruction test bed, and a 60-tonne biosolids PFAS destruction pilot was run for a major Canadian city. Independent evaluation matters here because most PFAS destruction claims in the market rest on vendor-run bench tests rather than field work at tonnage.
Spent media holds the PFAS it captured, so it becomes a concentrated waste that needs a destination. Options are landfill, which defers the problem, or thermal destruction, which ends it. Media regeneration only makes sense when the desorbed concentrate goes to a destruction step rather than back into storage.
Yes. Nelson ran a 60-tonne biosolids PFAS destruction pilot for a major Canadian city. Biosolids bring high moisture and organic content, so the process design has to handle water load and odour alongside the destruction requirement itself. Pilot data is what sizes a full-scale programme.
Separation technologies such as carbon, ion exchange and foam fractionation reduce volume and are appropriate on dilute water. Destruction is required once you hold a concentrate or impacted solids. Most complete programmes use separation first and destruction second, and the decision hinges on where the liability finally stops.
Use a laboratory accredited for the relevant PFAS method, sample with PFAS-free equipment and field blanks, and agree the analyte list up front because short-chain compounds are easy to miss. Results should report each compound individually so they can be compared with the limits that apply in your jurisdiction.
Yes. The United States sets enforceable federal drinking water limits with state-level soil and groundwater screening on top. Canada works from a Health Canada objective of 30 ng/L for the sum of 25 PFAS, with provincial guidance layered over it. The regulatory tracker records changes in both countries.
Light hydrocarbons come off in the 150 to 350 C band. Heavier crude fractions and PCBs need 350 to 550 C. Dioxins, furans and PFAS need high-temperature destruction with a secondary chamber holding the off-gas long enough to complete the reaction. The right band depends on the contaminant, soil moisture and the closure standard being met.
Direct-fired systems put the flame in contact with the soil, which moves high volumes quickly and suits hydrocarbon-impacted soil. Indirect systems heat the vessel from outside so the soil never touches the flame, which gives tighter control of the off-gas stream. Indirect is the choice for dioxins, PCBs and PFAS where the gas train does the destruction work.
Usually yes, once post-treatment sampling confirms it meets the applicable standard. A four-year field study published in the Agronomy Journal in 2022 followed thermally treated soil and tracked how it performed after replacement. Backfilling treated soil removes haulage cost, landfill tipping fees and the long-term liability that follows waste off site.
Thermal remediation applies controlled heat to contaminated soil or sludge so contaminants leave the solid phase and are then destroyed in a gas treatment stage. It covers thermal desorption, thermal oxidation and in-situ heating. The output is treated soil that meets a closure standard and an off-gas stream that has been burned out.
Feed soil is screened and metered into a rotating drum where heat drives volatile and semi-volatile contaminants off the solids. The vapour stream passes to a secondary chamber for destruction, then through cooling and particulate control before discharge. Treated soil discharges hot, gets moisture conditioned and is sampled before backfill.
In a direct-fired unit the burner flame and combustion gases contact the soil inside the drum. Heat transfer is fast, so throughput is high and fuel use per ton is low. The trade is a larger gas volume to treat downstream, which suits hydrocarbon-impacted soil where destruction targets are straightforward.
An indirect unit heats the drum shell from outside, so the soil never touches the flame. Off-gas volume stays small and concentrated, which makes the destruction stage easier to control and verify. Indirect firing is the configuration used for PFAS, dioxins, furans and PCBs where the gas train carries the compliance burden.
Match the firing mode to the contaminant and the verification you must show. Direct firing wins on tonnage and cost for petroleum hydrocarbons. Indirect firing wins where destruction efficiency has to be demonstrated on halogenated compounds or PFAS, because the smaller gas stream can be held at temperature and sampled properly.
A thermal oxidiser burns the vapour coming off the desorption stage. Burner design, chamber temperature and residence time decide how completely the organics are destroyed. Without an oxidiser a desorber only transfers contaminants from soil to air, which fails both the permit and the point of the exercise.
Typical designs hold the gas at temperature for one to two seconds, with the exact figure set by the compound being destroyed and the permit condition. Temperature, time and turbulence work together. Shortening any one of the three drops destruction efficiency, which is why the chamber is sized rather than improvised.
DRE is the percentage of a target compound destroyed between the inlet and the stack, measured by paired sampling during a performance test. Permits for hazardous organics commonly require 99.99 percent. Reporting DRE with the sampling method and test conditions attached is what separates a measured claim from a marketing number.
Carbon-fluorine bond breakdown needs sustained high temperature in the destruction stage, well above the desorption band that pulls PFAS off the soil. Two conditions matter as much as the peak figure: holding the gas at temperature long enough, and controlling the cool-down so shorter-chain products do not survive the exhaust path.
No. Desorption heats soil to volatilise contaminants and leaves the mineral soil intact for reuse. Incineration combusts the material itself. The practical consequence is that a desorption project can return treated soil to the excavation, while incineration produces ash that still needs disposal.
Sands, silts, clays and mixed fill all run, with pretreatment adjusting for the difficult ones. High moisture raises fuel demand, plastic clays need conditioning to avoid balling, and oversize or debris is screened out at the feed. A representative sample and moisture figure will tell you the throughput to expect.
Throughput depends on contaminant, moisture, target temperature and feed consistency rather than on a single nameplate figure. Nelson has sustained production at project scale, including 1.2 million tons of Bakken-crude-impacted soil at Tioga. Site-specific throughput is modelled from your analytical data before a schedule is committed.
Ex-situ treatment excavates the impacted material and processes it through a plant on site or nearby. It gives direct control of feed rate, temperature and sampling, so results are verifiable per batch. In-situ heating leaves soil in place and suits situations where excavation is blocked by structures or depth.
Yes, with indirect firing and a verified destruction stage. Nelson thermally destroyed 24,000 tonnes of PCB-impacted soil within a 60,000 tonne program at a remote Ontario gold mine, a Canadian first. PCBs sit in the 350 to 550 C desorption band, and the compliance work happens in the gas train where destruction efficiency is measured.
Treated soil loses organic matter and biological activity, both of which recover. A four-year field study published in the Agronomy Journal in 2022 tracked thermally treated soil after replacement and documented physical and nitrogen-cycling recovery. Amendment at backfill accelerates the process where the end use is agricultural.
A typical train runs oxidiser, rapid quench, particulate control and acid gas scrubbing, with continuous monitoring on the parameters the permit names. Quench rate matters for halogenated feeds because slow cooling through the reformation window is how dioxins come back after being destroyed.
Yes. The mobile fleet is built to travel and has operated on five continents, including Arctic conditions, a Pacific island tank farm and a remote Ontario mine site reachable only part of the year. Remote work is planned around logistics windows, power and fuel supply, and permit timing.
Permitting is jurisdictional. Most authorities require an air approval covering emission limits and monitoring, a waste handling approval, and a performance test demonstrating destruction efficiency before full production. Building the schedule around the regulator's clock rather than the mobilisation date is what keeps projects on track.
Nelson provides site-specific proposals rather than a public price list. Share available analytical results, estimated quantity, soil conditions and site access so the scope can be reviewed.
Where access is constrained, contamination is deep or sits under structures, or hauling large volumes is impractical, heating the ground in place can fit. The trade-off is verification: treated ground is never opened up, so sampling and groundwater monitoring carry the proof. Compare both routes against the same treatment boundary.
Petroleum hydrocarbons, BTEX, PAHs, chlorinated solvents, PCBs, dioxins and furans, PFAS, munitions constituents, creosote and coal tar. What varies is the temperature band, the firing mode and the gas train configuration required to reach the closure standard for each compound class.
Yes, with feed screening and clearance procedures agreed before material reaches the plant. Explosive residues such as TNT and RDX break down thermally, and the operational risk lives in the handling and inspection steps ahead of the drum rather than in the treatment itself.
Treated material is stockpiled in defined batches and sampled against the applicable standard, with the analytical suite matched to the contaminant of concern. Batches that pass go to backfill and batches that fail are reprocessed. The sampling plan is agreed with the regulator before production starts.
The terms describe the same function in most remediation specifications: a chamber that burns organics out of the vapour stream leaving the desorber. Oxidiser is the usual term in permit language, and it implies a designed chamber with stated temperature and residence time rather than a simple flame at the outlet.
Yes, with winterised feed handling and stockpile management. Frozen material has to be broken and thawed before it will meter evenly, and moisture from thaw raises fuel demand. Nelson has run production in Arctic and northern Canadian conditions where the schedule is planned around freeze and thaw cycles.
European projects reference best available techniques conclusions for waste treatment, which set expected emission ranges and monitoring practice for thermal processes. Meeting a BAT-associated emission level requires the gas train and monitoring package to be specified at bid stage rather than retrofitted after mobilisation.
Dioxins and furans need high-temperature destruction with verified destruction and removal efficiency, because partial treatment can form them again as the gas cools. Nelson has destroyed legacy dioxin residues in Vietnam and thermally destroyed 24,000 tonnes of PCB-impacted soil within a 60,000 tonne program at a remote Ontario gold mine, a Canadian first.
Yes. The destruction process is engineered to drive treated soil to Tier 1 values for the hydrocarbon fractions, confirmed by post-treatment sampling. Alberta Energy Regulator Directive 058 requires documented management of oilfield waste with a pathway that achieves closure, and destruction satisfies that test where landfill transfer often does not.
That depends on jurisdiction and on the verification record. Where post-treatment sampling shows the material meets the applicable standard, most authorities allow reuse as backfill on site. The classification question is settled by the sampling plan agreed before production, so it belongs in the permitting conversation.
A documented pathway showing the contaminant was destroyed or removed to the applicable standard, verification sampling that supports it, and a record the regulator will accept as final. Containment and monitoring can satisfy a regulator for a period, and it leaves an obligation on the balance sheet.
NATO Science and Technology Organization researchers ran a PFAS destruction test bed with Nelson's mobile thermal plant at Nelson headquarters during the week of 10 August 2026. The purpose was independent measurement of destruction performance on real PFAS-impacted material at working tonnage rather than a bench-scale demonstration.
Most PFAS destruction figures in the market come from vendor-run bench tests on small sample volumes. A defence science organisation running its own measurement protocol on a working plant changes the evidence class. Buyers and regulators can weigh the result against a third-party method instead of a supplier brochure.
At Nelson's headquarters facility, using the mobile thermal treatment fleet in its operating configuration. Running the test at a Nelson site meant the plant, the feed handling, the off-gas train and the sampling points were the same ones deployed to client projects rather than a purpose-built research rig.
Nelson's mobile high-temperature thermal system, with indirect desorption feeding a secondary destruction stage that holds the off-gas at temperature long enough to break carbon-fluorine bonds. Selection turned on mobility, tonnage capability and a gas train that can be instrumented for independent sampling.
Yes. Aqueous film-forming foam impacts at airfields, fire training areas and hangar aprons present the same soil and concentrate streams the test bed addressed. The difference on a defence project is contracting route, site security and the closure standard the installation is working to, rather than the treatment chemistry.
Brandon Hodge, Chief Revenue Officer, handles enquiries about the test bed and what it means for a specific site. Technical questions on plant configuration and off-gas verification route to John Tucker as technical lead. A short site description and any analytical data speeds the first conversation considerably.
Nelson technology was selected for a NATO Science and Technology Organization PFAS test bed. That is an evaluation programme for measuring PFAS destruction performance. It is separate from prime defence contracting, and Nelson describes it as test bed selection rather than a procurement award or a partnership.
Feed and treated-solids PFAS concentrations, off-gas behaviour through the destruction stage, operating temperature and residence time, and the mass balance across the system. Those four measurements together decide whether PFAS was destroyed or simply moved into another phase of the process.
The Hub is Nelson's open contamination data surface. It brings PFAS, hydrocarbon release and military contamination records into one mapped, filterable view with published methodology and version history, so a site owner or consultant can see what is documented near a location without filing a records request.
Public regulatory and agency sources, including federal and state or provincial release reporting and US Nuclear Regulatory Commission event notifications. Each dataset carries its source, refresh cadence and version in the published methodology so any figure on the map can be traced back to the originating record.
Roughly 20,000 reported releases across North America in the last twelve months, alongside tens of thousands of historical and event records. Counts move with each dataset refresh, and the released version history records what changed between updates rather than silently overwriting the previous figures.
Yes. The PFAS contamination map plots documented sites across the United States and Canada, filterable by state or province with regulatory context attached to each jurisdiction. It is a starting point for screening rather than a substitute for a site investigation on a specific parcel.
Yes. The military contamination map covers documented impacts at defence installations, with aqueous film-forming foam sites forming a large share of the PFAS records. Each entry links back to the jurisdictional regulatory picture that governs how a cleanup on that installation would be scoped.
Yes, under the published data licence, with attribution. Consultants, journalists and researchers use it for screening and context. The licence page sets out permitted use and the citation format, and the methodology page gives the provenance you need to defend a figure in a report.
Refresh cadence varies by source, because agencies publish on different schedules. Each dataset shows its own last-updated stamp, and every refresh is recorded as a version so a figure quoted last month can still be reproduced. The releases page lists what changed in each version.
Yes. Embeddable views exist for the PFAS, hydrocarbon and military layers, intended for agency pages, association sites and research write-ups. Attribution and the link back to the methodology travel with the embed so readers can check the provenance of what they are looking at.
The Hub
103,483 public records for PFAS, petroleum hydrocarbons and military sites across 63 states, provinces and territories.
Plus 14,738 release events reported across the United States and Canada in the last 12 months, spills, pipeline and rail incidents, fires and AFFF discharges, updated to 2026-08-16.