Presentation on theme: "Collecting a Stormwater Sample Annual CMTA Marine Trades Exposition October 5, 2010."— Presentation transcript:
Collecting a Stormwater Sample Annual CMTA Marine Trades Exposition October 5, 2010
THE BASICS Sample at designated outfalls annually, before October 1 st Storm event must be: > 0.1 inch in magnitude >72 hours from a previous storm of 0.1 inch or greater No snow or ice runoff Grab sample only Collect sample within the first 30 minutes of discharge Take all discharge samples during the same storm event, if feasible.
INFORMATION TO RECORD You will need this information for the storm event: – the date – discharge temperature – time of the start of the discharge – time of sampling – magnitude (in inches) of the storm event sampled – pH of the uncontaminated rainfall (before it contacts the ground) – duration between the storm event sampled and the end of the most recent storm event that produced a discharge. www.wunderground.com
SUPPLIES Sample bottles – Get them from the lab at the beginning of the sampling season Powder-free disposable nitrile or latex gloves. – These are sold by medical and laboratory suppliers. Do not use powdered gloves as the powder may contain metals that could contaminate metals samples such as zinc. Cooler(s) & ice Sharpie & paper
HOW TO FILL SAMPLE BOTTLES Wear disposable powder-free gloves when sampling. Grab samples with the stormwater entering directly into bottles supplied by your lab. Do not transfer the samples from another container if possible. Metal contamination of ordinary containers is common and household detergents often contain phosphorus. Keep your hands away from the opening to prevent contaminating the sample.
HOW TO FILL SAMPLE BOTTLES Do not rinse or overfill the bottles. The bottles supplied by your lab for some parameters (ammonia and phosphorus) will include small amounts of liquid preservative (generally a few drops). Fill the bottle to about ½ inch of the top to ensure that no preservative is lost. Do not transfer this liquid to other bottles. As soon as the sample is collected, cap the bottle and label it. It is important that the bottles are labeled correctly so that the lab will be able to identify samples by sample site and ensure proper preservation for each parameter. It is a good idea to place sample bottles in reclosable bags. Place the samples in a picnic cooler partially filled with ice. Plan to maintain ice in the picnic cooler until the samples arrive at the lab. Remember to make certain that the samples will be delivered to the lab soon enough for the lab to meet holding times.
Avoid Contamination Wear gloves Use only bottles supplied by lab Don’t transfer sample X X
Lessons Learned Figure out how you are going to get your sample before you have to! Check with your lab-some are open on Saturdays! Lab will tell you how long you have to get the sample to the lab (eg aquatic toxicity test has to be done within 36 hours of collection-lab wants it there within 24 hours)
Quarterly Visual Monitoring required in the 2011 SWGP Once each quarter for the entire permit term, you must collect a stormwater sample from each outfall and conduct a visual assessment of each of these samples. For monitoring purposes, quarters will begin on January 1, April 1, July 1 and October 1. The visual assessment must be made of a sample in a clean, clear glass, or plastic container, and examined in a well-lit area.
Visually inspect the sample for the presence of the following water quality characteristics: 1.Color 2.Odor 3.Clarity 4.Floating solids 5.Settled solids 6.Suspended solids 7.Foam 8.Oil sheen 9.Other obvious indicators of stormwater pollution. You must keep records of your quarterly visual monitoring & take steps to eliminate any potential problem. Quarterly Visual Monitoring continued
All photo credits: Washington State Department of Ecology Publication #02-10-071, revised March 2010 Questions?