Everyone seems to have questions about the proper way to collect an industrial stormwater sample. Unfortunately, the sampling requirements differ from state to state. With the new California Industrial Stormwater General Permit (IGP), all facilities need to collect samples for pH (in the field) and send samples to the laboratory for Oil & Grease (O&G) and Total Suspended Solids (TSS). If you are collecting samples from sheet flow across a site, it can be quite tricky. Here is a good video from Minnesota on how to create a dam and collect a stormwater sample. However, please note that if you are sampling for O&G you should not use a plastic container to collect the sample (in the video they use a plastic bag). Instead you should collect your industrial stormwater sample in the glass (amber) container supplied by the laboratory. The creation of a temporary dam should make it a lot easier.
In California, the IGP has an attachment (H) that covers sampling procedures. It is derived from the US EPA’s industrial stormwater monitoring guide. You can reference the guide here. For other resources on industrial stormwater sampling, see the list below:
Remember if you need help submitting your sampling results to SMARTS (California online system), check out our step-by-step guide and the California State Water Resources Control Board (SWRCB) discharger guide.