No Such Thing as a Free Sample

Grace Miller – Environmental Scientist, VET Environmental Engineering, LLC
Jamie McCrocklin – Environmental Manager, VET Environmental Engineering, LLC

“An ounce of prevention is worth a pound of remediation.” – The Iron Butterfly


The new general storm water permit for Illinois (passed by the IEPA on April 5, 2017 with a mandatory compliance date of October 5, 2017) requires permitted industrial facilities to collect storm water samples and send them to a lab for analysis.  Since a facility’s permit quarters are based on their permit (rather than calendar quarters), some facilities updated their Storm Water Pollution Prevention Plan (SWPPP) early to meet new requirements and have already completed their second quarter of sampling.  As the results come in and people have questions, VET is here to answer them and offer guidance.


What are benchmarks?

There are two kinds of sampling mandated by the IEPA under the new permit: benchmark sampling and impairment sampling.  Every industrial facility with a general storm water permit is required to sample for industry-specific pollutants and meet specific benchmarks (limits) mandated by the IEPA.  For auto recycling facilities, these pollutants and benchmarks include total suspended solids (TSS), total aluminum (Al), total iron (Fe), and total lead (Pb).  In order to be compliant with Illinois storm water regulations, the average results from your first four sampling quarters must be below the state-mandated benchmarks.  It is possible to request exemption from future sampling for the remainder of your permit once your 4-quarter average meets the benchmarks.


Do I need to sample for impairments?  

In addition to benchmark sampling, facilities whose storm water runoff discharges to an impaired (polluted) waterbody may be required to conduct annual impairment sampling to ensure additional pollutants aren’t discharged to the impaired waterbody.  Illinois provides a list of waterbodies that are impaired and the contaminants of concern.  Facilities are only required to sample for the pollutants they could reasonably be discharging.  For example: if the river that receives your storm water is polluted by fecal coliform bacteria, you aren’t expected to sample for fecal coliform bacteria because you don’t handle or process sewage at an auto salvage yard (no matter how much crap you take at work!).  However, if your river is polluted by oil and grease, you’re required to sample for oil and grease because an auto salvage yard is reasonably expected to discharge some oil and grease in its storm water runoff.


Facilities discharging to impaired waters must sample applicable impairment pollutants once per year for the duration of their permit.  If a benchmark pollutant is also an impairment pollutant (for example, if your river is impaired for total iron), you must continue to sample for total iron annually even after your 4-quarter average meets the total iron benchmark.  For those of you who are VET clients, VET has determined if you are required to sample for impairments and included appropriate bottles in your sample kits.  


Why were my Total Suspended Solids high?

TSS is a measurement of how much sediment is in your storm water sample.  TSS tends to be high for several reasons:

·       Low-flow events: not enough rain falls, resulting in sluggish flows, making it difficult to sample without disturbing sediment.

·       High-flow events: too much rain falls, resulting in fast, heavy flows that stir up lots of sediment.

·       Not enough ground cover: exposed dirt on your site gets picked up by runoff.

·       Excessive dust: runoff collects dust generated from roads and unpaved surfaces.

·       Poor sampling procedure: accidently scraping the ground, sampling from a stagnant puddle, or walking upstream of your outfall prior to sampling can increase sediment in your sample.


Why were my metals high?

Well…auto recycling yards have metal!  More specifically, metals (Al, Fe, Pb) tend to be high for the following reasons:

·       Exposure: metal parts, metal vehicles, metal buildings, metal racks – rainwater exposed to these items picks up trace amounts of metal.

·       Excessive dust: runoff collects metal dust, especially if you have processes that generate metal dust from cutting vehicles or parts.  

·       Poor sampling procedure: same deal as TSS.


Metals are often correlated with high TSS.  This is because fast-flowing water or water that has been disturbed picks up lots of sediment, including metals.  Stagnant water can also have high TSS and metals because no-flow conditions allow pollutants to collect and build up over time.


Aw man, I exceeded a benchmark.  Now what?

When you exceed a benchmark for one quarter, you should consider implementing control measures to try to lower your numbers and reevaluate your sampling methodology.  While a 1-quarter exceedance is not necessarily a permit violation, it does mean it will be harder to keep your 4-quarter average under the benchmark for that pollutant.  Get those numbers down before it becomes a bigger problem!


When your 4-quarter average exceeds a benchmark, you must implement control measures to try to lower pollutants, document the exceedance and new control measures in your SWPPP, and restart your quarterly sampling to test your control measures’ effectiveness.  Failure to do these things constitutes a permit violation.  For some yards, a 4-quarter exceedance occurs after only one or two sampling events: if you get a TSS result of 1,000 on your first sampling event and the TSS benchmark is 100, there’s no way your 4-quarter TSS average will be 100 or less – you’ve already exceeded your benchmark.  If you are a VET client, we are tracking your storm water results and will keep you informed of how you are doing each time you sample.


What can I do to get my numbers down?

General things everyone can do to lower TSS, Al, Fe, and Pb include:

·       Best Management Practices and inspections, Good Housekeeping inspections, and regular yard clean-ups.

·       Move parts and processes indoors where possible.

·       Minimize storm water exposure to fluids – keep ‘em covered and contained, and clean up spills right away.

·       Reduce dust as much as possible on your site.

·       Ensure your sampling procedure is sound.


Some common control measures you may consider installing to slow down storm water and trap pollutants include straw bales, green buffers (planting grass in bare areas), filter bags/socks/booms, and structural improvements (swales, berms, etc.).  The best control measures to try will depend on your site and the location of your outfall(s).  VET can help you decide what will work best for your site.


Any sampling tips for newbies?

·       Try to sample medium-flow events.

·       Do not sample from stagnant water.

·       Sample early – the sooner the better, especially before it gets dry in the summer!

·       Fill ALL your sample bottles!  For VET clients, this includes the unpreserved 1-liter plastic bottle you use to fill the preserved bottles – it’s not just a fill bottle, it must go to the lab!

·       If needed, use the cap from the unpreserved 1-liter plastic bottle to scoop water into the other sample bottles.

·       Pack as much ice as possible in your cooler with your samples – samples must be 4°C or colder when they get to the lab.

·       Make sure your cooler is clean and dry when you stick the shipping label on – we had a cooler detour to Memphis for a few days because the label came off!


Got Compliance?


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