Storm Water Monitoring Basics

Storm water monitoring in the automotive recycling industry, as required by the Indiana Department of Environmental Management (IDEM) includes both quantitative and qualitative elements.  Visual inspection, or qualitative analysis, helps to determine the presence or absence of chemical compounds in storm water runoff.  Analytical testing, or quantitative analysis, is used to determine if and at what concentration chemical compounds are present.  If chemical compounds are present at concentrations that exceed published guidelines or benchmarks the recycler may be required to implement control measures to reduce or eliminate pollutants in the storm water runoff from the facility.  These control measures are a part of the facility’s Storm Water Pollution Prevention Plan (SWP3).  Good sampling techniques are imperative to ensure that unnecessary control measures are not required due to contamination or uncertainty introduced as a result of poor sampling practices.      

Qualitative analysis in the form of visual inspections of each storm water outfall should take place quarterly. The data from the outfall inspection is not required to be submitted to IDEM in the form of a report; however, documentation is maintained at the facility as part of the SWP3.  Visual inspections are a quick and inexpensive way to observe the conditions at the facility and be alerted to a problem if one arises.  First, determine whether or not the outfall is operating properly: is the area free of clutter and debris, is the outfall clogged?  Secondly, observe the water flowing through the outfall.  Watch for foam on the water, a stirred up or muddy appearance (turbidity), matter floating on the surface, oil sheen, color of the water and any odors observed.  Observations are noted on a Quarterly SWP3 Site Inspection Checklist and maintained with the SWP3.    

Quantitative analysis in the form of analytical testing by a laboratory is required on an annual basis under the requirements of the Rule 6 Industrial General Permit.  Storm water sampling can be difficult and unpredictable based on the fluctuation of weather conditions; therefore, it is important to be prepared when a qualifying rain event arrives.  In order for a rain event to qualify for analytical testing it must be preceded by at least 72 hours without rain and the total rainfall from the target storm event must be greater than 0.1 inch.  In order to determine how much rain has fallen mount a rain gauge (must read down to tenths of an inch) clear from overhead cover.  Ensure that the rain gauge has been emptied from prior rain events so an accurate measure of rain fall for the sampling event is recorded.  Quantity of rainfall for the storm event will be recorded on the Storm Water Field Data Sheet and maintained in the SWP3.  If you were unable to obtain an accurate measurement from your rain gauge, some local agencies may provide this information.  In order to qualify for the annual storm water monitoring requirement under Rule 6, each sampling event must be a minimum of three months apart.      

When the rain fall begins, proceed to the first outfall.  If there is more than one outfall ensure that you use the laboratory supplied cooler with the correct outfall number annotated.  The cooler will contain approximately six sample bottles depending on the contaminants of concern for the facility.  There are eight contaminants of concern that all industrial facilities are required to monitor.  There are an additional four ‘salvage yard metals’ - copper, aluminum, iron and lead that are an additional requirement for automotive recyclers to monitor.  If the facility in question accepts and/or processes white goods (appliances) there may be an additional requirement to monitor for polychlorinated biphenyls (PCBs).  Some of the sample bottles may contain an acid solution preservative.  The labels on the bottles should indicate whether the bottle contains a preservative or not.  Another easy way to tell is the unpreserved bottles will appear completely empty while the preserved bottles will have a small amount of liquid in the bottom (the acid preservative).  Ensure that there is ice available to completely fill each of the coolers at the conclusion of sampling.  Begin filling in the known portions of the Storm Water Field Data Sheet. 

When water begins to flow from the outfall, the clock begins.  The samples are to be collected within the first 30 minutes of water discharging from the outfall.  For most laboratories, samples must be collected between Monday and Thursday due to short hold times on some analytical methods - to obtain accurate results the samples must be on the instrument at the lab within 48 hours.  Verify hold time requirements and hours of operation with your chosen lab prior to collecting samples.    

pH is a required field measurement meaning that it must be taken in the field at the time of sampling.  If you choose to collect samples independent of a consulting firm we recommend purchasing a digital pH meter.  This type of meter is available for less than $100 on the internet.  Colorimetric paper tests (litmus paper) are not currently an approved method for measuring pH.  Ensure that the pH meter is calibrated according to instructions that accompany the meter prior to collecting readings.  The pH value for each outfall should be recorded on the Storm Water Field Data Sheet and maintained in the SWP3.  

Latex gloves should be worn while collecting storm water samples.  Wearing gloves will protect your skin from exposure to acid and contamination, and will prevent cross-contamination of the samples from any chemicals that may be present on your hands.  Ensure that you change gloves between outfalls (if there is more than one outfall on the site) so that there is no cross-contamination from location to location.  When water begins discharging from the outfall, use one of the unpreserved bottles to transfer water from the outfall into the preserved sample bottles.  Ensure that each bottle is filled to the top (preferably with no air bubbles) but do not overflow the bottles because the acid preservative can be flushed out. 

Place the provided packing material in the bottom of the cooler.  Insert the large clear plastic bag in the cooler and arrange the sample bottles inside the plastic bag.  Place the bottles inside the bubble wrap sleeves, if provided.  Ensure that if there are glass bottles they do not lean against each other to prevent breakage.  Fill the rest of the plastic bag with ice ensuring that as much ice as possible is inside the cooler.  IDEM requires samples be kept at or below 4 degrees Celsius during shipping.  When the cooler is filled with ice tightly twist the excess top of the bag and utilize a zip tie (if provided) or knot the excess to secure the top of the bag. 

Ask your lab to pre-fill the chain of custody form to the extent possible.  Some line items will require filling out on the day the samples are collected.  If you are unsure how to properly fill in the chain of custody form it is recommended that you contact your lab.  The chain of custody form is a legal record.  Analytical results can be rejected, invalidated or challenged in court due to improper chain of custody documentation.  Ensure that a copy of the chain of custody is maintained in the SWP3 (usually the pink carbon copy) and that the remaining two copies (usually white and yellow) are enclosed in a plastic bag and mailed to the lab inside the sample cooler.  Complete the remainder of the Storm Water Field Data Sheet if necessary and add it to the SWP3. 

Use packing tape to securely close the cooler.  Date and sign the provided custody seal and place it over the edge of the lid and side of the cooler.  Ensure that the samples are shipped on the same day they are collected.  Ship the samples directly to the lab using a priority overnight delivery service or a laboratory courier service.  Most laboratories provide prepaid or bill recipient shipping documents.  The laboratory will provide a return shipment label with the cooler or the address will be written on the cooler itself. 

Automotive recyclers can save money by choosing to collect storm water samples internally without the assistance of an environmental consulting firm; however, it is critical to understand the importance of good sampling techniques.  Analytical testing is not cheap.  It is imperative that it is done correctly the first time as to not incur additional analytical fees.  Results below all applicable criteria and benchmarks serve to confirm a yard’s commitment to best management practices and environmental compliance.  Unfortunately, poor sampling techniques can introduce contaminants or uncertainties with regard to validity of the sample results that are not necessarily representative of a yard’s operation.  Fields Environmental, Inc. has conducted several classes with clients to enable them to properly collect storm water samples on their own.  If you are not sure how to do it, ask. 

The rainy season is upon us.  Happy sampling!

This article was originally featured in the April/May 2011 issue of ARI Magazine

Sara HamidovicComment