FAQs - Frequently Asked Questions

Q:  How do I know that my water is safe to drink?

A: The first line of testing always done on water to determine its suitability for drinking is the Coliform Bacteria Test.  This is a simple 24-hour test that determines if there are coliforms in your water supply. Coliform bacteria are organisms that are abundantly present in the environment and in our water supplies.  The presence of coliform bacteria will not likely cause illness.  However, its presence is an indicator that other, more harmful organisms, (pathogens) such as E. coli, may be present in the water system.  As a general rule, your water should be free of Total Coliforms to be considered totally safe to drink.  For more information please see the Department of Health's Coliform Bacteria in Drinking Water Page.

Q:  Should I boil my water if I find Coliform Bacteria in my drinking water?

A: Not necessarily.  As stated above, most Coliform bacteria are harmless and we live with them everyday.  However, it would be wise to go through all of the troubleshooting steps to try and eliminate the presence of the Coliforms, as their presence could indicate more serious problems and potentially Fecal or E. coli contamination.  If E. coli is found in your water, you would want to boil your water or drink bottled water until the problem was corrected.

Q:  How do I test for Coliform Bacteria and when can I do this?

A: Call us for a sample bottle, instructions and order form or stop by one of our labs to pick one up.  Samples must be recieved within 24 hours of sample time and kept refrigerated or in a cooler (below 40o F)  We will receive Coliform Bacteria samples M-Th only.  We do not accept Coliform Bacteria samples on Fridays. 

Q:  What do I do if Coliforms or E. coli are found in my water?

A: As mentioned above, if only Total Coliforms are found, it doesn't necessarily mean that your water is unsafe to drink.  However, it should move you to investigate your system a little more closely.  If E. coli is found in your water, you need to move to treatment options, most likely chlorination to disinfect your water supply.  For more information, please see the following resources:

Trouble Shooting Checklist for Coliform Contamination ~ Disinfecting Your Well

Emergency Disinfection of Small Water Systems


Q:  I have a private well.  How often do I need to test my water?

A: The recommendation is once a year for Coliform Bacteria and once every 3 years for Nitrate.  It is also recommended that at least twice, while you own the well, to test for arsenic—once in summer and again in winter – to check any seasonal influences that may occur.  More information and guidance, see:  Wells.

Q:  I just want to test my water safety and quality.  Where do I start and how much will it cost?

A: We recommend starting with the Coliform Bacteria test to make sure that it is safe to drink.  This test costs $28.  To ensure safety, the next recommended test is for Nitrates.  This test costs $48.  After that we would recommend a General Water Quality Package that looks for the following: (pH, Iron, Manganese, Conductivity, Turbidity (cloudiness), Total Dissolved Solids, Alkalinity and Hardness).   From there, we can always look at other specific trace heavy metals of concern, such as Arsenic or Lead, or other minerals such as Calcium or Sodium.  It all depends on what you want or need to know about your water.  More information see:  Wells.

Q:  What is nitrate and is it harmful?

A: Nitrate (NO3-) is a chemical found in most fertilizers, manure, and liquid waste discharged from septic tanks.  Natural bacteria in soil can convert nitrogen into nitrate, and then rain or irrigation water can carry nitrate down through the soil into groundwater, where it can get into your well water.  At low levels, nitrate is not necessarily a concern; however, it is regulated by the State Department of Health as an acute contaminant above 10 ppm.  Nitrate reduces the ability of red blood cells to carry oxygen.  Infants are especially susceptible to elevated concentrations of nitrate, leading to "blue baby syndrome".  Read more here8 Nitrate in Drinking Water

Q:  What is the hold time for Coliform and Nitrate samples?

A: Coliform samples have a 24 hour hold time.  Nitrate has a 48 hour hold time.  You are encouraged to get the samples to the laboratory ASAP after sampling.   If not possible, please keep samples cold (at or near 4o C). Coliform samples must be set up to analyze within 24 hours and  we do not accept Coliform Samples on Fridays! Receiving Nitrate samples on Fridays is discouraged; however, in emergency situations and with advance notice,  special arrangements may be made.

Q:  I'm a small water system manager and can't find/remember my system number!

A: You will find all the information you need on the Department of Health's Sentry Internet Water System Data website.  Click here.

Q:  How do I get my samples to you within hold time if I can't deliver them myself?

A: We routinely use several courier services for your convenience.  For businesses and utilities, the best option is Brett & Son same day service throughout most of Central Washington.  Call them first 1-800-572-2235, to find out if you are in their service area.  We also receive via UPS and Fed Ex for clients outside Brett & Son's area.  Call for a sample kit/cooler and we'll send it out to you with shipping instructions/labels, etc.  A shipping surcharge will apply.

Q:  Is lead and arsenic in the soil going to hurt my children or contaminate my vegetable garden?

A: Generally speaking, probably not.  However, lead and arsenic are both naturally occurring elements found in the soil and their levels could be elevated if you are on older orchard land, or know that lead-based paint or leaded gasoline has been a part of your property's history.  Arsenic and lead were both common components in pesticides prior to 1950.  The most common exposure to lead and arsenic is through breathing contaminated soil dust or from small children ingesting it.  Taking basic precautions is always advisable:  wash hands after playing outside or working in garden, wear gloves while gardening, wash vegetables before eating them, mop, dust and vacuum regularly to avoid breathing indoor dust and keep your pets clean.  If you are concerned you might live, work or play where the levels may be elevated, have your soil tested to find out.  For more information, see the following:  Arsenic in the Environment ~

How much is 1 part per million?

A: 1 part per million (ppm) is equivalent to 1 milligram per liter of water (mg/L).  This is true because a liter of water weighs 1000 grams and a milligram is 1 one thousandth of a gram, so 1 one thousandth divided by 1000 equals 1 millionth or 1 ppm.  Here are some fun concentration analogies that help us better understand this concept:

One-Part-Per-Million (ppm) is approximately equal to:

  • one automobile in bumper-to-bumper traffic from Cleveland to San Francisco
  • one inch in 16 miles
  • one minute in two years
  • one ounce in 32 tons
  • one cent in $10,000

One-Part-Per-Billion (ppb)

  • one 4-inch hamburger in a chain of hamburgers circling the earth at the equator 2.5 times
  • one silver dollar in a roll of silver dollars stretching from Detroit to Salt Lake City
  • one kernel of corn in a 45-foot high, 16-foot diameter silo
  • one second of time in 32 years
Information gleaned from:  Water On The

What does CFU and MPN mean?

A: CFU stands for 'Colony Forming Units' and refers to the number of viable bacterial cells in a sample per unit of volume.  For example:  50 CFU/100 mL means 50 Colony Forming Units per 100 mL of sample.  It is different from the direct microscopic counts that include both dead and living cells.

MPN stands for 'Most Probable Number' and refers to a method that uses dilution cultures and a probability calculation to determine the approximate number of viable cells in a given volume of sample.   It is useful when samples contain too few organisms for agar plates to be used or when organisms will not grow on agar.  For example:  50 MPN/100 mL means that the Most Probable Number of viable cells in 100 mL of sample is 50.

Is it safe for my children to swim in the Columbia River?

A: Absolutely, as long as you keep them from getting swept away by the current!  Based on a DOE study in 2005/2006, Fecal Coliform levels in the Columbia were less than 5 MPN/100 mL throughout the entire year.  Spikes can occur during high runoff times and in general, slower, warmer water will have greater potential for higher counts, but the overall quality of the surface water in the Central Washington region is quite high and the Fecal Coliform counts are well below the DOE's upper limit of 200 MPN/100 mL.  See:  Department of Ecology's Recreational Water Standards


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