Frequently Asked Questions
- How do I preserve my samples?
- Making Sense of Method Numbers
- Why does my water smell like rotten eggs?
- What is the blue-green stain in my sink?
- What is the white residue in my sink or on my drinking glasses?
- What is the black 'sand' in my water aerator screens? What is the black or gray stain in my sink?
- What is electrical conductivity?
- What is hardness?
- What do all these acronyms stand for?
- Why is there no MCL for Sodium?
- Where can I learn more?
- What do my results mean?
- What are Coliforms? Are they like E. coli?
How do I preserve my samples?
All of our kits include the correct amount of preservative for the amount and
type of the sample. If you are not using our kit, please reference the chart.
If you have any further questions about how to preserve samples, please contact us.
Making Sense of Method Numbers
Why are there so many ways to get the same analytical result? Simply stated,
each Federal program has its own favorite procedures written for a specific
federal rule. But fear not, there is some logic to the method numbers. Look
at the table below to determine which analytical method best fits your
needs. The prefix 'SM' stands for Standard Methods for the Examination of
Water and Wastewater, 18th Edition.
Why does my water smell like rotten eggs?
Your water may smell like rotten eggs because the chemical that causes the
odor is the same as that in the eggs, namely Hydrogen Sulfide (H2S). Hydrogen
Sulfide is a volatile gas. Sulfides are produced in environments where oxygen
is low. This low Oxygen condition is often referred to as a reducing
environment. Other forms of Sulfides that produce the rotten egg odor are
Manganese and Iron. There are certain bacteria that produce sulfides known as
sulfur reducing bacteria. To determine if you have Hydrogen Sulfide in your
water, just send us a sample. If you'd like more information or sampling
instructions, give us a call. Sulfides can be
treated by one of three ways:
- Remove one of the reducing conditions by killing the sulfur reducing bacteria
- Oxidizing the sulfur to a form that does not produce the odor such as ozonation or chlorination
- Stripping the sulfides out of the water by air sparging.
What is the blue-green stain in my sink?
If you have copper pipes the colored stain is a dissolved form of copper
being deposited on lighter colored surfaces. It is usually caused by
corrosive waters that have low pH (acidic) and often have a low mineral
content. Water is called the 'universal solvent' for a good reason.
Water that has a low mineral content and is only slightly acidic will
dissolve anything it can. If left unchecked the corrosive water will eat
through your copper pipes.
One method of treatment is to 'lime' the water. This increases the pH and adds calcium minerals that will tend to deposit on the pipes instead of allowing the water to corrode the pipes. To find out if your water is acidic or alkaline, just send us a sample. Call us for more information or sampling instructions.
What is the white residue in my sink or on my drinking
glasses?
This white residue is typically the result of 'Hard' water. The deposits are
often made up of calcium and magnesium carbonates, also known as limestone or
dolomitic limestone if it contains magnesium. You can test your water for
hardness by sending a sample to us. Give us a call
to find out more about how to take your sample.
This type of problem is usually treated by using a water softener.
What is the black 'sand' in my water aerator screens? What is the
black or gray stain in my sink?
This black 'sand' or gray and black stain is most likely manganese. We can
test your water for manganese and other contaminants.
This type of problem is usually treated by using a water softener or by sand filtration after the manganese has been oxidized. Call us for more information.
What is electrical conductivity?
Electrical conductivity is also known as conductivity or specific
conductance. It is a measure of the ease of the flow of electricity. For
those that understand electricity, conductivity is the mathematical inverse
of electrical resistance. It is used to help determine the total amount of
dissolved salts in water because it is related to the total amount of
dissolved ions (electrolytes) in solution. For instance, pure water has a
very low conductivity because water is a poor conductor though if you add a
teaspoon full of table salt (Sodium Chloride) the conductivity will sky
rocket. A value of 700 uS/cm is the maximum contamination level in drinking
water. If you'd like to know about electrical conductivity in your water,
Edge Analytical can help. Call us for sampling
instructions.
You can reduce the conductivity of water by distilling it or by a process known as reverse osmosis (R.O.).
What is hardness?
Hardness is property of water that tends to precipitate soaps and deposits
white residues on various surfaces. There is no known health problem
associated with hard water, it is just a nuisance. Levels of approximately
70 mg/L (4 grains per gallon, gpg) are considered hard. You can convert
mg/L (parts per million) to gpg by dividing mg/L by 17.1.
You can test your water for hardness by sending a sample to us. Give us a call to fi nd out more about how to take your sample.
Hardness is treated by water softening.
What do all these acronyms stand for?
PQL- Practical Quantitation Limit is the lowest concentration at which a
chemical or property can be measured or quantified by a specific method.
MDL - Method Detection Limit is defined as that concentration at which you are 99% certain that the value is greater than zero. If the observed result is between the MDL and the PQL values are flagged as estimated values, or 'J' values. The 'J' flag comes from the word judgment meaning you are reporting the value as a judgment call. MDLs are statistically derived using analyte spiked laboratory reagent water. Proper consideration should be used when using 'J' flagged data with relation to real-world samples.
MCL- Maximum Contamination level is the highest concentration of a contaminant that is considered to be safe.
Why is there no MCL for Sodium?
EPA has not established a maximum contamination level (MCL) for Sodium in
drinking water. They have however, published an advisory level of 20 mg/L
for those individuals that may have high blood pressure concerns.
Where can I learn more?
Safe Water Drinking Act - www.epa.gov/safewater/sdwa/
Public Water Systems - www.epa.gov/safewater/dwinfo/
Bottled Water - www.bottlewater.org
Helpful Links - Resources
What do my results mean?
If you need information regarding individual results, please
call us so we can help you. If you have the
reference number of your sample, that will allow us to assist you most
effectively. If you don't have this reference number, any information such
as client name or sample date will also help!
What are Coliforms? Are they like E. coli?
Coliforms are a large group of bacteria that are common in the environment and are generally
not harmful. Their presence usually results from a problem in the water system and can mean
that other contaminants and germs could enter the water. E. coli and fecal coliforms come from
human and animal wastes. These bacteria can cause illness.