This is a fact sheet about a chemical that may be found in some public or
private drinking water supplies. It may cause health problems if found
in amounts greater than the health standard set by the United States
Environmental Protection Agency (EPA).
What is Selenium and how is it used?
Selenium is a metal found in natural deposits as ores containing other
elements. The greatest use of selenium compounds is in electronic and
photocopier components, but they are also widely used in glass,
pigments, rubber, metal alloys, textiles, petroleum, medical therapeutic
agents, and photographic emulsions.
Why is Selenium being regulated?
In 1974, Congress passed the Safe Drinking Water Act. This law requires
EPA to determine safe levels of chemicals in drinking water which do or
may cause health problems. These non-enforceable levels, based solely on
possible health risks and exposure, are called Maximum Contaminant Level
The MCLG for selenium has been set at 0.05 parts per million (ppm)
because EPA believes this level of protection would not cause any of the
potential health problems described below.
Based on this MCLG, EPA has set an enforceable standard called a
Maximum Contaminant Level (MCL). MCLs are set as close to the MCLGs as
possible, considering the ability of public water systems to detect and
remove contaminants using suitable treatment technologies.
The MCL has been set at 0.05 ppm because EPA believes, given
present technology and resources, this is the lowest level to which
water systems can reasonably be required to remove this contaminant
should it occur in drinking water.
These drinking water standards and the regulations for ensuring
these standards are met, are called National Primary Drinking Water
Regulations. All public water supplies must abide by these regulations.
What are the health effects?
Short-term: Selenium is an essential nutrient at low levels. However, EPA
has found selenium to potentially cause the following health effects
when people are exposed to it at levels above the MCL for relatively
short periods of time: hair and fingernail changes; damage to the
peripheral nervous system; fatigue and irritability.
Long-term: Selenium has the potential to cause the following
effects from a lifetime exposure at levels above the MCL: hair and
fingernail loss; damage to kidney and liver tissue, and the nervous and
How much Selenium is produced and released to the environment?
Production in 1985 was reported to be 429,515 pounds. Selenium compounds
are released to the air during the combustion of coal and petroleum
fuels, and during the smelting and refining of other metals.
From 1987 to 1993, according to the Toxics Release Inventory
selenium releases to land and water totaled over 1 million lbs. These
releases were primarily from copper smelting industries. The largest
releases occurred in Utah. The largest direct releases to water occurred
What happens to Selenium when it is released to the environment?
The toxicity of selenium depends on whether it is in the biologically
active oxidized form, which occurs in alkaline soils. These conditions
can cause plant uptake of the metal to be increased. It is known that
selenium accumulates in living tissues.
How will Selenium be detected in and removed from my drinking
The regulation for selenium became effective in 1992. Between 1993 and
1995, EPA required your water supplier to collect water samples once and
analyze them to find out if selenium is present above 0.05 ppm. If it is
present above this level, the system must continue to monitor this
contaminant every 3 months.
If contaminant levels are found to be consistently above the MCL,
your water supplier must take steps to reduce the amount of selenium so
that it is consistently below that level. The following treatment
methods have been approved by EPA for removing selenium: Activated
Alumina, Coagulation/Filtration, Lime Softening, Reverse Osmosis.
How will I know if Selenium is in my drinking water?
If the levels of selenium exceed the MCL, the system must notify the
public via newspapers, radio, TV and other means. Additional actions,
such as providing alternative drinking water supplies, may be required
to prevent serious risks to public health.
This is a factsheet about a chemical that may be found in some
public or private drinking water supplies. It may cause health problems
if found in amounts greater than the health standard set by the United
States Environmental Protection Agency (EPA).
Drinking Water Standards:
|Mclg: 0.05 ppm (parts per million)
Mcl: 0.05 ppm
Selenium Releases to Water and Land, 1987 to 1993 (in pounds):
Note: This fact sheet is part of a larger publication
adapted from U.S. EPA publication: EPA National Primary Drinking Water
|Top Five States*|
|Copper smelting, refining
* Land totals only include facilities with releases greater
than 1000 lbs.
Systems to Reduce Selenium in Your Water:
Goldline Reverse Osmosis Drinking Water System
PuROLine 5000 Reverse Osmosis Drinking Water System
PuROTwist 3000 Reverse Osmosis Drinking Water System
PuROTwist 4000 Reverse Osmosis Drinking Water System
Valueline Reverse Osmosis Drinking Water System
Filters to Reduce Selenium in Your Water:
Desal Osmonics 50 Gallon Reverse Osmosis Membrane
PuROTwist TQ56-36FC Reverse Osmosis Membrane
PuROTwist TQ56-50FC Reverse Osmosis Membrane