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DOH PUB #331-225 December 2015 If you need this publication in an alternative format, call [PHONE REDACTED] (TDD/TTY call 711). This and other publications are available at www.doh.gov/eph/dw. For More Information If you have questions about coliform sampling procedures, call our regional office: Eastern Region Spokane Valley [PHONE REDACTED] Northwest Region Kent [PHONE REDACTED] Southwest Region Tumwater [PHONE REDACTED] Our publications are online at wa.gov/doh/eh/dw/publications/publications.cfm Related Publications Revised Total Coliform Rule (331-556): An explanation of the federal Revised Total Coliform Rule, including explanations of key terms, assess ments, and violations of the rule. General Sampling Procedure (331-219): An overveiw of how to sample water in your system, including explanations of best practices and key terms. Coliform Sampling Procedure Coliform Sampling Procedure We recommend that you follow these steps when collecting your sample. If instructions from your lab are different, please call us for clarification. Most sample kits contain a: Sample bottle Lab slip Rubber band Protect the sample bottle from contamination before and after sampling. Don’t rinse it and don’t expose it to direct sunlight, heat, or unsanitary conditions. A model sampling station in Kent. ---PAGE BREAK--- Do not set the cap down, touch any part of the cap that touches the bottle, or let anything touch the rim of the bottle or the inside of the cap. Step Six Hold the bottle under the stream of water. Be careful not to let the bottle touch the sample tap. Fully fill the bottle to the neck or indicated fill line. Don’t allow it to overflow. Remove the bottle from the water flow and carefully screw the cap back on. Step One Follow your Coliform Monitoring Plan to collect routine, repeat, and raw source samples from sites throughout the distribution system. You must collect raw source samples from sites prior to all treatment and close to the source while the source pump is running. Sample taps should represent the water in your distribution system. Avoid poor sample sites such as swivel faucets, hot and cold mixing faucets (with a single lever), leaky or spraying faucets, drinking fountains, janitorial sinks, frost-free hose bibs, and faucets below or near ground level. Step Two Remove any attachments from the faucet, includ ing aerators, screens, washers, hoses, and water filters. If you choose to disinfect the sample site before collecting the sample, be sure to flush the site thoroughly to remove all disinfectant. Step Three Turn on the cold water only and let it run with a steady stream for at least five minutes. Before collecting the sample, turn the water down to a thin stream (about the width of a pencil), then let the water run one minute. If you chlorinate your system, measure the free chlorine residual and note the measurement on the lab slip. Step Four There may be some liquid or powder in the sample bottle to neutralize chlorine. Do not rinse it out. Step Five To avoid contamination while taking the sample, hold the bottle near the bottom with one hand, hold the top of the cap with the other, and then unscrew the cap. Step Seven Complete the lab slip. If there was anything unusual about the sample collection, note it on the lab slip. Lab forms vary. It is important to include at least the following information: Collection date and time System type (Group A or B) Water system ID number Water system name Contact information Sample location (street address or other location identifier) Type of sample (check ONLY ONE Type: Routine, Repeat, Raw, or For Information Only) Chlorine residual—even if it’s zero. Step Eight Secure the lab slip to the bottle with the rubber band. Deliver the sample to a certified lab or a designated drop-off location for the lab as soon as possible. Lab analysis must begin within 30 hours after you collect your sample.