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Field case study  /  Hydrocarbon bioremediation

Track bed remediation at a
chemical plant railroad

Industrial chemical plant  ·  Houston, Texas  ·  3,000 cubic yards

Contaminated track bed treated in place over four and a half months, with rail service running throughout.

29,000
mg/kg TPH
at the worst point
Under 900
mg/kg TPH
across the whole site
3,000
cubic yards
treated in place

The site

Railroad tracks running through an industrial chemical plant, contaminated by years of operation.

The track bed and surrounding soils held brake fluids, grease, diesel fuel, creosote and other halogenated hydrocarbons. Runoff from the track area was migrating into the floodplain, which triggered a cleanup requirement.

Why conventional remediation was not an option

Doing it the usual way meant lifting track sections, excavating the bed and the gravel beneath it, and hauling the waste to landfill or an incinerator. The remediation cost alone would have been substantial. The cost of stopping rail service for the duration would have been far higher. Any approach that closed the line was out.

What we did

Six treatments over four and a half months, each combining a biodegradable surfactant, nutrients and a hydrocarbon-degrading microbial blend, applied to the track bed and the surrounding contaminated ground. Surface washing was carried out as needed between treatments. Labour was minimal and the track stayed open throughout.

Worst sampling point
Before treatment
29,000
mg/kg TPH
After treatment
Under 900
mg/kg TPH
From 2.9 times over the benchmark to more than 11 times under it
Best sampling point
Before treatment
4,000
mg/kg TPH
After treatment
Under 900
mg/kg TPH
Already under the benchmark at the start, and lower again after treatment
The benchmark above is the Railroad Commission of Texas cleanup level for crude oil in non-sensitive areas, one per cent by weight, or 10,000 mg/kg. Quoted for scale only. Cleanup criteria vary by state, by programme and by site, and the governing criterion for this site is not stated here.

Four and a half months, 3,000 cubic yards, and not one day of lost rail service.

What this does and does not show

It shows that a mixed hydrocarbon contamination, including creosote and halogenated compounds, can be brought down in place on ground that has to stay in daily use.

It does not show that every track bed behaves this way. Initial concentrations here ranged from 4,000 to 29,000 mg/kg depending on where the sample was taken, and the treatment schedule was built around that spread. Your site will need its own.

How the work was done. Delivered through our partnered Houston microbiology and genomics laboratory, which has run this class of work for more than thirty-five years. RAD Microbes LLC was founded in 2024. Contamination levels were measured by laboratory TPH testing before treatment and after four and a half months.

Start with a discovery call

Every site is different, and a short conversation tells us far more than a sample does. Talk us through what you are dealing with and we will tell you honestly whether biology is the right answer for it. If it is not a fit, we will say so on the call.

Call +1 949 333 9072