Does it feel like communicating with labs is like talking to aliens? It feels like they speak another language, 200.8 what and MDL who? Don’t worry you’re not alone out there in this universe! Many facilities run into communication issues when attempting to obtain sample kits for stormwater collection or simply to understand how to extract your sample results from the lab report. Most of these miscommunications occur because (1) labs think everyone should speak their strange acronym-heavy, method-focused language, and (2) facilities are usually not sure what parameters they should even be sampling for. That is why it is important to take the following steps to ensure that you and your lab have a friendly and understanding relationship from the start!
1. Know Your Required Sample ParametersBefore you call the lab, be prepared to request exactly what you will need, this way it is not a guessing game for you or the lab representative. How can you find out what your facility needs to sample for? Well, first you need to know your Standard Industrial Classification (SIC) Code, which can be found in your stormwater permit. Once you know your SIC Code then you can utilize your state’s stormwater permit to look up what parameters are required based off of your SIC Code. For example, California has a table in the Industrial General Permit (IGP), TABLE 1: Additional Analytical Parameters (below), which demonstrates what parameters in addition to the three minimums, total suspended solids (TSS), pH and oil and grease, that a facility will need to sample for based off of their SIC Code. Some state’s permits are separated by sector, which is still based off of your industrial activities at the site but is generally associated with a letter instead of a series of numbers (i.e. Sector R) for this information, use the EPA Industrial Stormwater Fact Sheet Series. If you are sampling for media other than stormwater (i.e. soil, hazardous materials, wastewater, etc.) refer to permits, consultants assisting with the project and other regulatory materials that can assist in figuring out what specific parameters you will need to sample for.
2. Find the Appropriate Sample MethodsSimply knowing what you need to sample for, like total aluminum, might not be enough to ensure compliance with your stormwater regulations. So, once you have figured out what parameters you need to sample for, you should dig a little deeper and figure out the methods required for that parameter in your stormwater permit. Certain methods are more sensitive, meaning they can detect lower levels of the pollutants, which is why specific methods are generally required to ensure that the method detection limit (MDL) is lower than the thresholds set forth by the state. For California stormwater regulations, this information can also be found in the IGP in TABLE 2: Parameter NAL Values, Test Methods, and Reporting Units as seen in the picture below.
3. Finding a Lab and Reaching OutOk, so you have figured out what parameters your facility needs to sample for, and also identified the specific methods needed for each parameter. Congratulations, the hard work is over! Now you need to actually find a lab that can supply you with what you need to collect and analyze your samples. During your search for a lab it is important to keep a couple things in mind; (1) the lab needs to be certified to conduct analyses on regulatory samples, for California they must be ELAP certified (refer to the Water Boards national map for ELAP certified labs), for other states your permit should clearly layout the requirements if there are any, (2) it is a commercial lab meaning that it is open to the public, as some labs are municipal, meaning that they only take samples from municipalities. Those are the two most important things to verify, but location, hours of operation and available services are also things to consider based on your facility’s needs. This is also a great time to ask if they can provide you with a chain of custody (the sheet of paper that tells the lab what the samples will be analyzed for and provides a record of who had possession of the samples) that is already filled out with the requested parameters and test methods. That way all you have to worry about is filling out the sample date, time, and collector. Once you decide on the lab you would like to work with, it’s now time to reach out and get setup with an account, request your sample kit(s) and coordinate on how collected samples will get from the facility back to the lab for analysis. Once you get into contact with a project manager, explain what type of samples you are taking (i.e. stormwater, wastewater, drinking water, soil, etc.) this way the rest of the conversation is clear. Now for the exciting part, run down your list of parameters and test methods like you’ve worked at a lab for years, and revel in your glory as the project manager is lost for words and all of your hard work pays off! Now simply collect your stormwater samples, not sure how to collect stormwater samples? Check out our blog on sample collection techniques. Last thing that will need to be decided on is will staff members from the facility transport the collected samples to the lab, or will a courier (someone from the lab who picks up samples and delivers new sample kits) be picking up the samples from the facility? Most labs charge for courier service, but you might be able to get it as an included bonus. For either delivery method it is imperative to keep stormwater samples on ice, or in the fridge (NOT the freezer!!!) to keep them cold before arriving at the lab as they will test the temperature when the samples arrive and if they are over 4℃ or 39 ℉, a flag will be placed on the lab report. The idea is that if the samples are too warm it can change the chemistry and ultimately the results of the analysis.
4. Learn How to Read your Lab ReportWhoohoo! You have successfully done your research, set up your lab, collected samples and sent them in for analysis, great work! Two weeks later you receive the lab report with all those numbers and acronyms that look like hieroglyphics, but they are really your results. Now it’s time to decode this report and get your results uploaded into your regulatory website (yikes!!). I know I said the hard part was over, and many of you may feel that I lied (maybe just a little), but I promise after this blog you will be able to dissect that lab report to extract the results and submit them to your state. Many permits have a time limit on when sampling data needs to be uploaded to the regulatory website, some are from the time of receipt of the lab report like California the data should be uploaded within 30-days of receipt of the report, other states it’s just once per quarter. Make sure to know dates and deadlines for data upload based off of your permit requirements. The report release date should be on the first page of the report (see below), generally adjacent to the project managers signature.
Next thing that should be verified is the sample collection date, the received date which is the date that the samples were received by the lab, and the analyzed date which is the date that the analyses were run for that parameter. The received date and analyzed dates are important to ensure that the hold times are not exceeded. All parameters have a “hold time” which is the amount of time that a sample can be held before analysis by the lab. As an example, total suspended solids has a hold time of 7 days, if the sample does not get received by the lab until 8 days after the sample is collected, then it has passed it’s hold time. Though analyses can still be run past the hold times, there will be a flag placed on the report, similar to the temperature reading mentioned earlier, that means they cannot validate that the results are accurate.
Next is to determine the sample location so that you know which data point you need to enter the results for.
Finally, you can finalize your data entry with the test method (verify that it is the same as your requirements that you already provided to the lab because they are people too and we all make mistakes 🙂 ), and the units. You will generally need all of this information to upload the results into your state’s database.
Occasionally, depending on how low your results are, you will need to enter either the method detection limit (MDL) or the reporting limit (RL). The MDL is the lowest level at which a method can detect the parameter it is analyzing for. Whereas, the RL, not to be confused with the threshold limits set by your permit, is actually the limit at which the lab can say with confidence the result is accurate, or that it is “quantifiable”. When a result falls between the MDL and RL it is flagged (another flag on the play!) and is considered “detected but not quantifiable” or DNQ, though this is not a negative flag as the others generally are.
Lastly, make sure to not upload the QC Data that is generally found in the last few pages of the report. It will be labeled QC Report or something to that effect on the top of the page (see below). This data is NOT your sampling results, DO NOT UPLOAD. These analyses are run to ensure that the equipment being used to test your media is accurate.