Q: What are W.E.T. Lab’s hours?

A: W.E.T. Lab experts are available for consultation at no charge to the general public between the hours of 10:00 a.m. and 4:00 p.m. Monday thru Thursday (except holidays). Additional consultation times may be available by appointment. Please call (530) 677-5776 for scheduling. We do our best to answer our telephone personally; however, if you get our voicemail please leave a message with your return phone number and we will return your call just as soon as possible.

Q: What will the tests show?

A: The basic potability test determines whether or not your water sample is contaminated by bacteria. Our basic test is a “presence or absence” test that simply tells if there is any Total Coliform* or E. coli in your water.  If you have no reason to believe your water may be contaminated – i.e. no cloudiness, bad smell, and no one has had G.I. (gastrointestinal) problems – then this test is the simplest and least expensive way to verify its potability.

*Some microorganisms are quite difficult and expensive to test for. Therefore, Total Coliform is the indicator organism used by scientists as well as the State Department of Health to determine if there may be more harmful organisms (such as Giardia or Cryptosporidium) present in the water.

Q: What are the Additional Tests?  Do I need them?

A: 1)Quanti-Tray Analysis (or Bacterial Enumeration) determines how many bacteria are present in the sample and therefore the level of contamination in the water supply.  This is helpful when a well tests positive for bacteria because it helps the remediating well specialist or engineer know the type and amount of remediation media needed for the specific well. Comparing the results of one density analysis before remediation efforts and one after (usually about eight weeks later) can help determine the effectiveness of the remediation.  When a well does test  positive for microbial contamination, a client’s next questions are usually; “How much bacteria is there and how serious is the contamination?”  These questions cannot be answered unless a bacterial enumeration has been done.  It is impossible to go back and perform this test retroactively. For this reason, if you feel your well or water system may be contaminated you may want to consider ordering this test (an additional $10) to be done at time of initial sampling. Doing so may save you time and money in the long run.

2)  A Heterotrophic Plate Count determines how many different kinds of bacteria are present in a sample – whether “friendly” or not. This test is generally not necessary for private well owners.

Q: Does this white powder belong inside my sample bottle? What is it?

A: Yes! The enclosed factory sealed bottle contains Sodium Thiosulfate in powdered form. This chemical is used to neutralize any residual chlorine that may be present in your water which would invalidate the accuracy of the test.  (It is similar to the chemical used to de-chlorinate a fish tank.) Please do not pour it out or overfill the sample bottle. REMOVAL OF THIS NECESSARY POWDER WILL INVALIDATE YOUR TEST RESULTS.

Q: Can I take my sample from a kitchen spray nozzle or garden hose?

A: Please do not! Samples from any kind of nozzle or hose will usually fail testing. They will most likely show the presence of contaminating bacteria even if the water itself is free from contamination. We strongly urge you to take the sample exactly as described on the How To Take A Sample page.  If you do not, and the sample tests positive for bacteria, it will be impossible from that sample to determine whether the water is actually non-potable or if the contamination is simply from the non-sterile nozzle or hose, requiring a replacement sample.

Q: Can I take my sample from a bathroom sink?

A: For the same reasons outlined above, this is not recommended.  However, if it is your only option, be sure to disinfect the faucet thoroughly as described on the  How To Take A Sample page.

Q: How often should I have my water tested?

A: The EPA and State and local Health Departments recommend that private wells be tested – and if necessary treated – at least once every year. Some government websites recommend testing every 6 months; once in the rainy season and again during dry, hot weather.

Q: My sample tested positive for bacterial contamination. What should I do?

A: If you suspect your water supply may be contaminated we strongly suggest you use a bottled water – or boil your water for 1 minute – for drinking and brushing your teeth until after testing, remediation, and retesting have produced a clean sample free of bacteria. We suggest you have your well disinfected by a licensed well professional, such as a well driller, pump specialist, or water treatment operator. (Especially if this is your first time to have your well treated.)

Q:  How long do I wait to re-sample after well treatment?

A: W.E.T. Lab suggests waiting a minimum of two weeks – preferably two to three months – after treatment before re-testing. A well is “like an English muffin with many nooks and crannies”. Once coliform and /or E. coli get inside a well, it becomes easy for bacteria to find a foothold in one or more of these crannies or small spaces. Because of this, well treatment does not always accomplish the task of eliminating 100% of the bacteria on the first try, but is not uncommon to require repeat treatments before potability is obtained. Waiting at least two weeks prior to re-sampling will help ensure that any bacteria which may have survived treatment have had sufficient time to re-grow enough to be detected.

Q:  What if I need to re-test right away in order to process a loan or re-finance?

A: This is when it is especially prudent to enlist the aid of a qualified well-specialist for treatment. They may have access to more effective treatment options than what the general public has access to. Then, even if a previously contaminated well passes potability right away, we at W.E.T. Lab are concerned about the health of the homeowner: Therefore we would strongly suggest additional re-sampling 2 weeks to 3 months after well treatment to ensure the bacteria has not re-colonized the well. This is especially important if the well has tested positive for E. coli.

Q:  I have watched a professional chlorinate my well and have studied the process sufficiently that I feel qualified to chlorinate the well myself: Is it okay if I use pool chlorine?

A: NEVER use pool chlorine to disinfect a well!  It is toxic to humans and may permanently damage pump wires. Also, please be careful to provide adequate air circulation around the area where you are working (such as inside a pump house) so that you will not be overcome by toxic fumes.  And, please do not over-chlorinate! “The more the better” is not the case when it comes to treating a well. Over-chlorination may cause serious problems with well bio-fouling, in addition to damaging the pump wires. Truly it is best to consult with a well treatment specialist if you are not experienced.  

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