KarateKid72

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.

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.

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.