Techniques For Sampling Drinking Water (1970)

[Music] thank you [Music] [Music] thank you stop and consider for a moment the miracle of water made up of two parts hydrogen to one part oxygen it's one of the most common substances found on Earth along with the air that we breathe it is the prime sustainer of life without it nothing would grow and the world would look like this virtually nothing could live almost everything that man does or tries to accomplish is dependent in some way on water yet this precious substance water is treated with casual indifference by Society man in general takes water for granted after all there's so much of it that until some kind of disaster occurs he gives little thought to its preservation or quality every single day in the year our water resources are bombarded by both natural and man-made pollutants that threaten the quality of our drinking water most of them are invisible most of them are potentially dangerous there is a clear and distinct need to protect the quality of our water especially drinking water through careful sampling and detailed laboratory analysis we must constantly guard against the invasion of our water supply by these pollutants to ensure the highest quality of our water for our friends and Families in 1974 Congress passed the Safe Drinking Water Act which required the establishment of the national interim primary drinking water regulations but these regulations while setting forth national standards for the quality of our drinking water can't ensure the maintenance of this quality the job of maintaining those standards the responsibility for protecting the consumer from contaminated drinking water is a task that requires regularly scheduled sample collection and laboratory analysis you the water sampler have a large responsibility since it is you who must deliver to the analytical labs the actual samples representing the water that our community drinks you then are an important critical member of a team if the sample is not truly representative of the water in the distribution system then you will have no accurate measure of the quality of what we drink thus the care that you take in the collection preservation and storage of samples is key to being able to accurately measure the quality of your community's drinking water a proper schedule of sampling the use of proper containers and the correct selection of the sampling site are important with the most vital step in the entire sampling process is the collection of the water to be tested more things can happen at this critical stage to influence the Integrity of the sample than at any other time four basic principles should be followed in a proper sampling procedure these are the drinking water tap must be free of contaminating devices the sample container and cap must be handled with caution to avoid contamination all data must be recorded clearly on the label of the sample container and in the field log water samples must be treated with care during transport once again the drinking water tap must be free of contaminating devices the sample container and cap must be handled with caution to avoid contamination all data must be recorded clearly on the label of the sample container and in the field log water samples must be treated with care during transport remember these four cardinal principles as we now go through the detailed procedure for collecting a bacteriological sample as an example of these principles as they are applied in the field first select the location of the drinking water tap preferably indoors but if it is outdoors avoid dust splashing rain snow and any other possible sources of contamination sure come on in thank you foreign examine the tap carefully avoid swing spouts as they can be sights for bacteriological growth which could contaminate the sample make certain the tap is situated high enough so that your sample container can be placed under it without risk of contact between the mouth of the container and the faucet be sure that you choose the cold water tap make certain that no device is attached to the faucet that might contaminate the water check carefully for aeration devices hose attachments water purification devices or screens within the faucet by carefully examining it and remove them if present once you have removed any attachments check the faucet to be sure it is clear now the collection process begins turn on the cool water tap and allow it to run for several minutes or until a constant temperature is attained this will ensure that the sample to be collected is representative of water in the main and not of water in the interior Plumbing next reduce the water flow to an even non-splashing stream remove the cap or stopper and the covering from the sample container do not let them come in contact with anything that will contaminate them the best procedure is to hold them in your hand and avoid touching the inside with your fingers or gloves even the bacteria from a single fingerprint can ruin the sample now hold the container directly under the water flow do not rinse out the container prior to sampling since the container May hold a chemical reducing agent such as sodium thiosulfate do not allow any part of the container to touch the faucet fill the container leaving enough room at the top to allow proper mixing at the lab an inch or two from the top will do avoid splashing and do not let the water overflow from the container now take the container out from under the tap while the water is still flowing put the cap on immediately and then turn off the water the procedure just described is for bacteriological sampling however even though other types of sampling require slightly different procedures the same principles of sampling continue to apply now it is time to label the sample container remember principle number three all pertinent data must be legibly recorded on the container label and in the field log first make sure that your label is clean and big enough to contain all the recorded information and can be securely attached to the container use a non-smearing waterproof marker and be sure to write carefully to ensure a clear readable permanent and concise record when you have finished attach the label to the container and make sure it is secure record all of your data in the field log as each sample is taken your data should include the date and time of the sample the location and type of sample and identification of the water supply from which you have taken the sample if chlorine residual or turbidity or other field tests are to be conducted they should be completed at this time and notations properly made in the logbook and on the label the sample is now ready for transport to the laboratory this is the stage where a great many of the samples are invalidated by careless handling remember principle number four the water samples must be treated with extreme care during transport in order to assure that the water sample does not change in quality before it reaches the laboratory it is good general practice to avoid subjecting the samples to extreme temperature changes and to make sure that you get the samples to the lab as quickly as possible some samples require special handling during transport so be sure you clearly Mark the package with your sampling objectives bacteriological organic inorganic or radionuclide if the samples must be mailed to the lab be sure that they do not arrive on a weekend or holiday this completes the basic steps of a sound sampling procedure but depending on the type of sampling being performed slightly different techniques may be required let's take a look at each basic type of sampling first bacteriological sampling to begin remember to assure that bacteriological samples are not contaminated by picking a faucet that is clear of contaminating devices such as aeration devices or swing spots if such devices are attached remove them during shipment bacteriological samples should be kept cold to inhibit any additional bacteriological growth during Transit pack samples carefully in an ice chest just as you would with soft drinks for a picnic never never leave any kind of sample sitting in direct sunlight or in a closed car unprotected from the sun's Heat the intense heat generated under these conditions can adversely affect the quality of the sample if you mail or ship your bacteriological sample to the laboratory not only should the sample be kept cold but it should also arrive so that analysis can begin within 30 hours from the time the sample was collected a longer time span could result in bacteria that are not representative of the actual quality of the water now let's look at inorganic sampling in almost every case samples required for inorganic chemical analysis are preserved by adding a specified quantity of a preservative preservatives are added to keep chemicals in the sample from deteriorating or collecting on the walls of the container if the preservative has been added to the container prior to sampling do not rinse the container out make sure the label on the container shows the preservative that was added samples which contain a preservative need not be iced during transport but care should be taken to protect them from extreme temperatures samples collected for organic chemical analysis require different methods of collection when trialomethanes or other volatile Organics are to be determined the sample bottles must be filled so that no airspace exists in all cases the bottle should not be rinsed before collecting the samples all organic samples should be iced during transport samples required for radionuclide analysis don't require special collection procedures preservatives are necessary and caution should be exercised as with all other sample types so as not to expose them to extreme temperatures in every single case prompt analysis of the samples that you have collected is necessary to obtain results representative of the water in your system the samples should be transported as quickly as possible now your part of the job is completed if you have followed the procedures outlined your samples will be valid for analytical purposes let's take a moment and review the four key sampling principles the drinking water tap must be free of contaminating devices the sample container and cap must be handled with caution to avoid contamination all data must be recorded clearly on the label of the sample container and in the field log water samples must be treated with care during transport now you've got it right well let's see as we watch our star sampler Joe forget it all he's a likable guy very sociable today he's working on samples for bacteriological analysis he's on his sampling route and is about to arrive at Dina's luncheonette to collect a sample can I get you some coffee howdy Harvey honey hello hello [Music] what have you been up to chicken water I came to check your water you did you're gonna eat lunch with us no it's too early for lunch okay it's right back there you don't mean we're contaminated do you oh and it goes check it out make sure uh let's five minutes okay I'll be right back foreign [Music] wait a minute Joe you forgot to examine the tap for contaminating devices looks like there's a screen on that faucet Joe you've forgotten principle number one check the faucet for contaminating devices no another No-No principle number two guard the Integrity of the container don't let it touch anything and by all means protect the cap and cover from contamination don't put them down anywhere where they can become contaminated well he's consistent anyway consistently wrong remember Joe fill the container to about one or two inches from the top don't let the water spill over or splash and remove the sample container from the water flow before you turn off the water Daddy down heck fart it's worth it that's it Joe don't disappoint us you've done away with principle number three all data must be recorded clearly on the label and the label should be securely attached to the sample container tough life huh well it's about quitting time and I have a feeling that you aren't going to pack that sample so that it gets treated with care during transport you leaving me so soon I'll be right back I gotta put this in my car okay you're gonna come back in for a drink oh that's an a forever okay unbelievable Joe you've messed up every one of the principles of good water sampling that sample container should be iced during transport and never never left in the hot sun Joe it's very important to you and to your community Joe is an exaggeration of course but every year Laboratories receive thousands of water samples that are invalidated because of this same kind of abuse the results are far-reaching the sampler wastes time the lab Personnel wastes their time analyzing a meaningless sample and both of them waste public funds but most important is the fact that the water supplier does not know the true quality of the water supplied to the consumer remember the responsibility is yours avoid the simple mistakes and follow the proper sampling procedures review the four basic principles the drinking water tap must be free of all contaminating devices the sample container and cap must be handled with caution to avoid contamination all data must be recorded clearly on the sample container and in the field log book water samples must be treated with care during transport the quality of the water we drink is everyone's concern but the responsibility to collect samples that truly represent that quality is yours no matter how large or how small the water system you could take pride in knowing that the accuracy of the samples you collect really helps ensure that the water being consumed by your friends your neighbors and your family is of the highest quality [Music] thank you [Music] foreign [Music]