WATER SAMPLING & TESTING Introduction: According to the well code, all new drinking water wells are required to be sampled for the presence of coliform bacteria prior to being placed into service. The well owner is ultimately responsible for collecting the samples, and the well contractor is responsible for notifying the well owner of their need to collect the samples. Some local health departments may require additional sampling such as partial chemical or arsenic. This additional sampling will typically be described on the well construction permit. General Rules: • The sampling location selected should reflect the quality of water coming from that portion of the water supply being evaluated. • For new installations, the sampling tap at the pressure tank is most commonly used. • For routine monitoring of both existing and new installations, the sampling tap at the kitchen sink is often used. • Sampling from the well head is the most practical method of determining the quality of water from the well itself. This eliminates the influence from service lines, pressure tanks, valves, etc. Sampling at the pressure tank evaluates the following: 1. piping (drop pipe and service line) 2. pressure tank 3. pump 4. well structure 5. aquifer Sampling at the kitchen sink evaluates the following: 1. piping (drop pipe and service line) 2. treatment equipment 3. hot water tank 4. pressure tank 5. pump 6. well structure 7. aquifer Coliform Bacteria Sampling Procedures: 1. Flush sampling tap (into pail if at pressure tank). 2. Reduce flow. 3. Obtain correct sample container. 4. Remove seal from sampling container. 5. Carefully remove cap and do not set down. 6. Collect sample (do not fill above designated fill line). 7. Recap bottle immediately. 8. Shake bottle to dissolve thiosulfate tablet. 9. Promptly mail or deliver the sample to a certified laboratory for analysis. Sample Interpretation: • Coliform is an indicator. • Coliform distribution is not uniform. • Sampling is just a “snapshot” in time. • Repeat unsafe = problem. RULES Rule 161: (2) Prior to placing well into service: 9 Flush all chlorine (use test kit). 9 Collect 1 or more samples. 9 Coliform shall not be present. (3) Owner responsible for collection of water sample. (3) Driller must notify owner of the requirement to sample. (4) A driller is not required to redisinfect a well or pump installation if unacceptable results are obtained from a tap other than the sampling faucet. Rule 158: Sampling tap must be installed: 9 At least 8 inches above the floor. 9 In a convenient location. 9 Downturned faucet. Drinking Water Sampling and Testing Overview Laboratory The DNRE drinking water laboratory and numerous other private laboratories provide testing services for the evaluation of drinking water. The DNRE lab testing services include physical, chemical and microbiological analyses. It is recommended that individuals use laboratories certified by the state of Michigan to analyze drinking water samples. A laboratory may be certified, but only for microbiological analysis and perhaps not for volatile organic compounds (VOC), even if the laboratory has the capability to perform that testing. To receive a list of state certified labs go to www.michigan.gov/deq and click on “Water”, then “Drinking Water”, then “Contamination Investigation”. General If investigating a specific problem, always consider how the well location (including sample location) is related to suspect sources of potential problems. When selecting a sampling point, consider the following: • Collect the sample as close to the well as possible, generally near the pressure tank. Caution: Do not enter confined spaces such as well pits to collect samples. • Outside taps may be used for sample collection. These taps allow for easy access and more extensive flushing. Typically, these taps supply untreated water. • Intermediate plumbing or connections to the source may contribute other contaminants. • Samples should be untreated (without softener, filter, etc.). • Do not collect samples from plumbing materials not approved by NSF for potable water use. The water to be sampled should be representative of ground water quality. As a general rule, let the water run at full flow from the sampling point through two pump cycles or 10 minutes before collecting the sample. This may not be practical, as it may be difficult to dispose that volume of water in a basement or crawl space. The water may run through another tap, such as an outside or laundry sink tap for two pump cycles, then flush the sampling tap with 10 to 15 gallons of water into a pail before collection. For a recently chlorinated well, sample only after the well water is free of chlorine. Check the water for chlorine residual before collecting samples. VOC samples may show disinfection byproducts such as chloroform, bromiform, and other trihalomethanes (THM). For new wells constructed with approved plastic casing, be aware that volatile organic analyses may detect by-products of construction such as methyl ethyl ketone (MEK) and tetrahydrofuran (THF). Volatile organic analyses of water from new wells may also detect toluene, which can be a by-product of well construction/development. If toluene is present as a result of construction/development, thorough flushing will gradually diminish its concentration. • After flushing the water supply system at full flow, reduce the water flow to provide a stream of water approximately the size of a pencil diameter. • Do not open sample container until the moment of sample collection. Do not touch the inside of the bottle or cap. • Follow the recommended procedures below for the specific type of sampling container(s). • Do not use felt markers that contain solvents near sample vials. Complete laboratory analysis request form in pencil or waterproof black ink. All sample bottles use the same laboratory form. One form must be completed for each bottle submitted. • Attach form to sample bottle or enclose within the single mailing container. • Return samples to the laboratory immediately. • Types of common analyses are explained below with the bottle, or kit number, in parentheses. Volatile Organic (36VO) • Do not collect a sample where chemical odors are detected. Collect the sample in a location free of organic chemical vapors (gasoline, fuel oil, paint, paint thinner, and solvents). • Do not touch the inside of the cap, septum or bottle. Do not rinse the bottle or allow the water to overflow. A preservative must be added to the bottles at the time of collection. Do not drop the septum out of the cap. If the septum is dropped or touched, do not use the bottle. • Fill the bottle so as to exclude all air. Fill completely with low flow until water rounds above the top of the bottle. Carefully replace and tighten cap. Invert. If an air bubble appears, remove the cap and carefully add water. Repeat until no air remains in the vial. • Chill the sample and transport to the laboratory immediately. Nonvolatile Organic (36NV) • Do not touch the inside of the cap or bottle. • Do not rinse the bottle or allow water to overflow. Bottles contain a dechlorinating agent. Fill to bottom of bottle neck. • Chill sample and transport to the laboratory immediately. Metals (36ME) • Do not touch the inside of the cap or bottle. • Do not rinse the bottle. • Do not filter LSS samples. The sample will be automatically acidified at the time of sample collection. • Fill to bottom of bottle neck. • Transport to the laboratory immediately. Chilling of sample is not required. Cyanide (36CN (unchlorinated) or 36CNa (chlorinated)), Hydrogen Sulfide by titration (36HS) or Hydrogen Sulfide presence/absence (CH2S), and Ammonia (36AC) • Do not touch the inside cap or bottle. • Do not rinse the bottle. Do not allow the water to overflow. These bottles contain a preservative to either keep cyanide or ammonia in solution or to precipitate sulfide in the hydrogen sulfide analysis. Fill to bottom of neck. • Cyanide samples need to be chilled. • Hydrogen sulfide and ammonia do not need to be chilled. • Transport to the laboratory immediately. Bacteriology (30) • Do not touch the inside cap or bottle. Do not rinse the bottle or allow overflowing. Bottle contains a dechlorinating agent. Fill vial to 100-milliliter (ml) line. • Chill sample and transport to the laboratory immediately. United States Environmental Protection Agency (U.S. EPA) holding time limit is 30 hours. Partial Chemical (32) and Complete Minerals (33) • Do not touch the inside cap or bottle. Do not rinse the bottle. Fill bottle to bottom of neck. • Chill sample and transport to the laboratory immediately. U.S. EPA holding time for nitrate (NO3) and nitrite (NO2) is 48 hours. Transporting Samples to Laboratory Samples kept inside cars during summer months can reach excessive temperatures and adversely affect sample results. Temperature sensitive samples (noted above) during collection day should be kept in an insulated container at approximately same temperature as ground water (50°F, 10°C). • DO NOT let ice come in contact with laboratory analysis request forms. • DO USE ice cubes in sealed plastic bags. • DO USE reusable ice packs (i.e. “Blue Ice” or type with hard plastic shell). The best method of delivery is transporting directly to the DEQ laboratory the same day as collection inside the insulated container. It is acceptable to mail samples. U.S. Mail will deliver to DEQ laboratory Lansing post office box that is checked twice per day. Bottles must be properly packaged in laboratory mailing containers provided to avoid breakage during transit. UPS provides the best route for sending time sensitive samples or when requesting RUSH analysis. • Bottles must be properly packaged in laboratory packaging containers bearing address label provided to avoid breakage during transit. • Time sensitive samples should not be sent this route as arrival to post office may be after staff pick up time (6 and 9:30 AM M-F).