Few-Ganache1416 OP t1_j8s3nqf wrote on February 16, 2023 at 3:44 PM

For anyone interested, below is a link to all the EPA documents available to the public.

https://response.epa.gov/site/doc_list.aspx?site_id=15933

KarateKid72 t1_j8u8d5k wrote on February 16, 2023 at 11:53 PM

That’s some questionable numbers on the surface waters. A lot of J-flags, especially on compounds like Phenol. 8270-SIM could get better results on the SVOCs. I saw a hit for 1,4-dioxane too. Fascinating. I’d love to know if they used a heated purge, since that’s a requirement for 624.1.

Few-Ganache1416 OP t1_j8uarx9 wrote on February 17, 2023 at 12:10 AM

There were quite a few hits above the risk standards they referenced in surface water, but they seem to be localized to the immediate area near the spill. 1,4-Dioxane is typically found with chemicals like VC and TCE as an additive, so that isn't too surprising. Given that I am not so sure on the 8270, what SVOCs would you expect here? VC doesn't really degrade into anything I can think of on the SVOCs list, I could be wrong though. I don't really know what you mean by the 624.1 comment, that is for GC/MS laboratory analysis typically. I am not an expert in everything though, so if you would like to expand it may be helpful for everyone.

KarateKid72 t1_j8uevnx wrote on February 17, 2023 at 12:40 AM

My career has been in CWA/SDWA/RCRA analyses. The reason I brought up EPAMethod 624.1 is that there is a requirement for the sample to be heated during analysis to 80C. The analysis gets tricky if the sample is preserved to pH<2 (it hydrolyzes and would give low bias on the results).

The PQLs for SVOCs are a different matter. They are higher than I would expect for storm water given the advances in technology available. I can think of several commercial labs that could achieve much lower limits, which would be more protective. And there are 3 different sites. Two have very low PQLs (the lowest verifiable concentration, usually the lowest standard in the calibration curves), but site 2 has much higher elevated PQLs. That leads me to believe they didn’t collect enough sample (a liter is required for SVOCs, whereas 40mL is required for VOCs). I assume the DRO/GRO/ORO are from the fuel spill of the train itself and not one of the cars.

KarateKid72 t1_j8ufrz4 wrote on February 17, 2023 at 12:46 AM

The second site has PQLs that are higher by a factor of 50x from the other two sites. I want to see the instruments they are using, see the procedures they are following, see results of quality control assessments. This looks very strange.

Few-Ganache1416 OP t1_j8ufwhp wrote on February 17, 2023 at 12:47 AM

Oh got it for 624.1. Oh I see, yes I agree, the PQLs are much higher they could also be due to turbid samples requiring significant dilution. I cant imagine why they wouldn't be able to collect enough sample for surface water unless its a dry creek bed.

StructureNo8299 t1_j8vxhxf wrote on February 17, 2023 at 9:33 AM

Probably more of a convenience thing with cooler space & shipping demands and perhaps bottle availability.

Few-Ganache1416 OP t1_j8wmoy4 wrote on February 17, 2023 at 2:04 PM

I highly doubt they are concerned with a matter of convenience in this scenario and I also doubt they are shipping these samples rather than direct transport for faster results.

Few-Ganache1416 OP t1_j8xl9eg wrote on February 17, 2023 at 5:52 PM

I found the laboratory analytical results for the surface water samples at the site, apparently one of the bottles broke in transit from the site to the lab, so I think you are right about not having enough sample for the analysis.