Category: Drinking Water Contaminants


 

This site is supported by Ron Perrin.  Since 1997 my company Ron Perrin Water Technologies has been a leader in underwater inspection and cleaning for the water utility industry. We offer underwater inspection and cleaning services to municipal water utilities so they do not need to drain water tanks or towers to inspect or clean them. Our city drinking water comes from surface waters (lakes, rivers or streams) or ground water (well water).  After the water is treated it is sent to the water storage tanks & towers where it waits to be used at your tap.  Over time sediment builds up in these tanks  the sediment can be a safe habitat for bacteria protozoa and even viruses.

Our cleaning service is performed by Commercial Divers(also called line air because they are breathing surface supplied air on an umbilical line). They wear dry suits that completely seal them in their own environment.  The diver is then washed down with a chlorine solution before entering the water supply.

Once inside the water tank or tower our diver can quickly remove the accumulated sediment from the interior floor of the tank. Removing the habitat that can hide bacteria and other contamnants makes the water safer to drink and safes the utility money by reducing chlorine cost.   because the contaminants are no longer growing and depleting the chlorine reserves.

WORMS IN TAP WATER!
Worms are ok in water if you’re fishing, but Thursday morning, the 30th of July, I woke to see a news story about worms in drinking water. I live in Fort Worth but the story was getting wide coverage from CBS Houston. I had to know more about this! I went to work and told Ryan, our director of media & video production, to pack a bag because we were headed to Houston. We went to the heart of the story, Woodland Acres, which is a subdivision in Old River-Winfree about 25 miles east of Baytown, Texas, to see the worms for ourselves. We met several residents who were still had worms coming out of their tap water. Read more on our new page www.WORMSINDRINKINGWATER.COM

National Primary Drinking Water Regulations: Finished Water Storage Facility Inspection Requirements Addendum to the Revised Total Coliform Rule.

EPA is planning to propose an addendum to the Revised Total Coliform Rule (RTCR) to strenghten public health protection by including finished water storage facility inspection (SFI) requirements. In the preamble to the July 2010 proposed RTCR (75 FR 40926), EPA requested comment on the value and cost of storage facility inspection and cleaning. (Hide)

EPA received comments regarding unsanitary conditions and contamination that can be found in finished water storage facilities that are not routinely inspected and cleaned, including breaches and accumulation of sediment, animals, insects, and other contaminants. The Agency is developing an SFI proposal in order to allow interested parties to again comment and provide any additional relevant information. EPA is planning to propose and request comment on requirements for public water systems to periodically inspect the interior and exterior of their finished water storage facilities at least and to correct any sanitary defects found. Any potential requirements would apply to all public water systems that have one or more finished water storage facilities. Like the 2013 final RTCR, the proposed storage tank inspection requirements would maintain or improve public health protection by reducing cases of illnesses, and possibly deaths, due to exposure to waterborne pathogens.
          ———————————————————————————————————————-
8/15/14 UPDATE:  At a Water Quality Conference in Austin, Texas earlier this month, I spoke to an EPA official who advised me the inspection requirement of the RTCR will stop short of requiring storage tanks to be inspected.  The rule will be implemented by the States and in full effect by 2015.  We may see a wide range of different interpretations as we compare State to State.
Another EPA spokesperson confirmed to me that a water storage tank inspection would be an important part of assessing the system if there would be a violation under RTCR.  In addition, if sediment was found in the storage tank, cleaning the tank and removing the sediment would be considered a corrective action.  The official refused to go on camera and asked not to be named due to EPA rules against speaking for privately owned companies.
This blog will post new developments on the RTCR as news becomes available.

Click here for more information including the proposed time line: Regulatory Development and Retrospective Review Tracker

Image

Sediment being removed from potable water storage tank 2014. (c) Ron Perrin Water Technologies.

From my conversations with others in the industry this is what

their concerns are for storage tanks.

None of the tools that are outlined below have worked to get PWSs to

clean their tanks every 5 years.  Unfortunately, it comes down to the

personal preference of each PWS’s Manager whether the tank is cleaned on

a schedule recommended by guidance.

Some manager’s religiously clean their tanks every year, or every three years but for others, it never

occurs to them to clean their tanks.

This is unacceptable and can

sicken hundreds and cause fatalities.  Because nothing has worked, it is
vital for the protection of public health to create a regulatory (not
guidance) back stop that any system that has not cleaned and inspected
their storage tanks in the last 5 years would incur a violation.  This
is not a burden to those PWSs that have done what is right and followed
guidance but it does provide equal public health protection for those
who have not followed guidance.  We need to ask ourselves, where will
the next waterborne disease outbreak, like Alamosa occur?   In Alamosa,
one person died and 1300 others were sickened in a waterborne disease
outbreak that was caused due to neglect of their storage tanks – this
was completely preventable.  This person died needlessly.  Create a
regulatory backstop to prevent waterborne disease outbreaks from ever
occurring from such a preventable cause.

AWWA guidance and EPA whitepapers do not work to get PWSs to clean their
tanks every 5 years!

AWWA Manual M42 recommends tanks be drained, inspected and cleaned at
least every 3 years.  This same recommendation is reflected in EPA’s
Whitepaper on Finished Water Storage Tanks.  Kirmeyer, one of the
industry’s most  knowledgeable persons on storage tanks and water
quality, recommends tanks be drained, cleaned and have a comprehensive
inspection every 3  to 5 years.  These recommendations are ignored and
unknown to most PWSs.  They are recommendations, they are nice to do and
as a consequence, tanks are not cleaned and inspected and that’s why we
continue to find feet of sediment inside of tanks.  They don’t realize
the public health significance that sediment and holes large enough to
allow birds, rodents and insects into their tanks can have, it can lead
to waterborne disease outbreaks.  Salmonella can last for months in a
wet environment.  Clearly guidance does not work to get PWSs to clean
their tanks every 5 years.  We need a regulatory backstop to get PWSs to
do what is right for public health protection.  This does not need to be
delayed to study this to death, this is one of the most simple and
practical ways to protect public health.

None of the 50 states use their Significant Deficiency authority in
sanitary surveys for ground or surface water to clean their tanks every
5 years

None of the states have “not cleaning and inspecting their tank within
the last 5 years” as an item on their list of significant deficiencies.
The reason is States don’t realize the public health significance of
sediment buildup and/or the significance of breaches to a storage tank.
That is why cleaning and inspection is not on State’s significant
deficiency lists for sanitary surveys.  When you have both sediment
buildup and breaches, that is a fatal combination, and what causes
waterborne disease outbreaks like in Alamosa, Colorado.  One person died
from this Salmonella waterborne disease outbreak in Alamosa, he died,
from something that is totally and completely preventable.  There is a
class action lawsuit ongoing at this time.   You may justly ask why
aren’t we having waterborne outbreaks at more systems?  Because along
with sediment buildup and holes you need an event that would scour this
disease laden sediment into the distribution system.  Unfortunately,
that event that would awake this sleeping giant of a public health
concern is uncontrolled (e.g., fire flow, poor operation, power outages,
etc.) and that is completely unpredictable.  Gideon, Missouri had holes
that allowed salmonella contaminated bird feces into their tank but, it
was not until they underwent a flushing program that accidentally
drained their tank and flushed contaminated sediment into their
distribution system that the outbreak occurred.  This series of events
that led to hundreds of illnesses and 7 deaths stands ready to occur
again at hundreds of PWSs across the country.  EPA you have given the
drinking water industry a tremendous opportunity to prevent hundreds of
serious illnesses and fatalities from occurring from something the
industry already recognizes is vital to perform by creating a regulatory
backstop.  But, and I can not say this strongly enough, if you are
relying on significant deficiencies to achieve this goal it is not and
will not work unless there is a regulatory back stop.

State regulations that require PWSs to inspect their tanks only do not
work to get PWSs to clean their tanks every 5 years!

In the State of Texas where they have regulations that require PWSs to
have yearly inspections do not clean their tanks even when provided
overwhelming video and picture evidence of the sediment buildup.  They
don’t clean their tanks because they are not required to.  It is
impossible to inspect the floor of a tank when the sediment is not
removed.  The State of Wisconsin has recommendations for inspection
every 5 years, yet in the City of Brookfield two tanks were last cleaned
at a frequency of 7 years with 4 to 12 inches of sediment and another at
a 15 year frequency with 28 inches of sediment.     Clearly regulations
and recommendations to inspect only do not work to get PWSs to clean
their tanks every 5 years.  We need a regulatory backstop to get PWSs to
do what is right for public health protection.

State recommendations to inspect and clean their tanks do not work to
clean tanks every 5 years

Recommendations are largely ignored by PWSs.  Actually it’s much worse,
PWSs don’t even know these recommendations exist.  For example in the
State of Minnesota they had recommendations that stated ” All water
storage tanks should be inspected, cleaned and disinfected on an annual
basis.  Cleaning and disinfection should take place more frequently when
there have been identified water quality issues”.  The City of Moorhead,
one of the largest PWSs in the State, was unaware of any such
recommendation.  Recommendations to inspect and clean do not work to get
PWS to clean their tanks every 5 years.  We need a regulatory backstop
to get PWSs to do what is right for public health protection.

Protect public health over politics

Many agencies purporting to protect small systems (e.g., Rural Water,
RCAP, etc.) from the high costs of regulations are the very same systems
with the highest levels of sediment and most significant holes in their
storage tanks.  Many of these small systems can clean their tanks by
themselves with their own staff and fire hoses.  If these agencies were
truly helping these systems they should be assisting them to comply with
industry guidance of cleaning their tanks every 3 years.  If this were
the case such agencies would be able to say don’t worry about a
regulation to inspect and clean your tank it will never apply to you
because we ensure your tank in cleaned every 3 years.   The cost of a
cleaning a storage tank does not compare to the cost of a waterborne
disease outbreak and defending yourself from class action lawsuits.

Oocyst – An oocyst is the thick-walled spore phase of certain protists (sporozoans), such as Cryptosporidium and Toxoplasma. This state can survive for lengthy periods outside a host and is very resistant.

I know what a Cryptosporidium spore is but I must confess this was the first time I saw Oocyst.  So I looked it up on Wikipedia, the free encyclopedia.  The results are posted above.  I am in the process of writing a book and I came accross that word in “Final Long Term 1 Enhanced Surface Water Treatment Rule”.

A excerpt of the book is posted below.  I want to encorage everyone to use Wikipedia, It is a free site that I use often.  They are now taking donations to keep the site free.

 

Physical removal is critical to the control of Cryptosporidium because it is highly resistant to standard disinfection practices. Cryptosporidiosis, the infection caused by Cryptosporidium, may manifest itself as a severe infection that can last several weeks and may cause the death of individuals with compromised immune systems.  

 

 

Final Long Term 1 Enhanced Surface Water Treatment Rule

 

The LT1ESWTR extends further this necessary protection from Cryptosporidium to communities of fewer than 10,000 persons.  Today’s rule for the first time establishes Cryptosporidium control requirements for systems serving less than 10,000 persons by requiring a minimum 2-log removal for Cryptosporidium. The rule also strengthens filter performance requirements to ensure 2-log Cryptosporidium removal, establishes individual filter monitoring to minimize poor performance in individual units, includes Cryptosporidium in the definition of GWUDI, and explicitly considers unfiltered system watershed control provisions.

 

Twelve waterborne cryptosporidiosis outbreaks have occurred at drinking water systems since 1984 (Craun, 1998; USEPA, 2000a). The largest of the known outbreaks occurred in Milwaukee and was responsible for over 400,000 illnesses and at least 50 deaths (Hoxie, et al., 1997; MacKenzie et al., 1994); other known outbreaks have occurred in smaller communities and have involved many fewer people. An incident such as a rainstorm that flushes many oocysts into the source water or causes a sanitary sewer overflow combined with a water treatment plant upset could allow a large pulse of oocysts to move past the multiple barriers of a water treatment plant.

 

To read more about the “Final Long Term 1 Enhanced Surface Water Treatment Rule”

 

See the Fact Sheet at: http://www.epa.gov/safewater/mdbp/lt1eswtr_fact.html  or

For general information on the LT1ESWTR, contact the Safe Drinking Water Hotline, at (800) 426-4791, or visit the EPA Safewater website, http://www.epa.gov/safewater/mdbp/lt1eswtr.html.

 

For copies of the Federal Registernotice of the final regulation or technical fact sheets, contact the Safe Drinking Water Hotline at (800) 426-4791. The Safe Drinking Water Hotline is open Monday through Friday, excluding Federal holidays, from 9:00 a.m. to 5:30 p.m. Eastern Time.

 

 

 
 
 

 

http://www.epa.gov/safewater/disinfection/tcr/pdfs/whitepaper_tcr_biofilms.pdf

 

A list of possible Drinking Water Contaminants has been posted by the EPA

The link below gets you top the EPA page that has National Primary Drinking Water Regulations (NPDWRs or primary standards) are legally enforceable standards that apply to public water systems. Primary standards protect public health by limiting the levels of contaminants in drinking water. Visit the list of regulated contaminants with links for more details.

http://www.epa.gov/safewater/contaminants/index.html#micro

The problem with the EPA web site it that it is constantly in motion with thousands of web pages and hundreds being added daily.  I have elected to repost the list of list of regulated contaminants here to make it easier to find when people search the web.  The EPA posted this list in June of 2003 with this identifier #. EPA 816-F-03-016.  I have personally found this information to be very hard to find when searching their site. In addition to that you never know when it will be taken down.  All the more reason to re-post it here where more people will be able to find it when searching for Drinking Water Contaminates.

Microorganisms
Contaminant MCLG1
(mg/L)2
MCL or TT1
(mg/L)2
Potential Health Effects from Ingestion of Water Sources of Contaminant in Drinking Water
Cryptosporidium (pdf file)
zero
TT 3
Gastrointestinal illness (e.g., diarrhea, vomiting, cramps) Human and animal fecal waste
Giardia lamblia
zero
TT3
Gastrointestinal illness (e.g., diarrhea, vomiting, cramps) Human and animal fecal waste
Heterotrophic plate count
n/a
TT3
HPC has no health effects; it is an analytic method used to measure the variety of bacteria that are common in water. The lower the concentration of bacteria in drinking water, the better maintained the water system is. HPC measures a range of bacteria that are naturally present in the environment
Legionella
zero
TT3
Legionnaire’s Disease, a type of pneumonia Found naturally in water; multiplies in heating systems
Total Coliforms (including fecal coliform and E. Coli)
zero
5.0%4
Not a health threat in itself; it is used to indicate whether other potentially harmful bacteria may be present5 Coliforms are naturally present in the environment; as well as feces; fecal coliforms and E. coli only come from human and animal fecal waste.
Turbidity
n/a
TT3
Turbidity is a measure of the cloudiness of water. It is used to indicate water quality and filtration effectiveness (e.g., whether disease-causing organisms are present). Higher turbidity levels are often associated with higher levels of disease-causing microorganisms such as viruses, parasites and some bacteria. These organisms can cause symptoms such as nausea, cramps, diarrhea, and associated headaches. Soil runoff
Viruses (enteric)
zero
TT3
Gastrointestinal illness (e.g., diarrhea, vomiting, cramps) Human and animal fecal waste

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Disinfection Byproducts
Contaminant MCLG1
(mg/L)2
MCL or TT1
(mg/L)2
Potential Health Effects from Ingestion of Water Sources of Contaminant in Drinking Water
Bromate
zero
0.010
Increased risk of cancer Byproduct of drinking water disinfection
Chlorite
0.8
1.0
Anemia; infants & young children: nervous system effects Byproduct of drinking water disinfection
Haloacetic acids (HAA5)
n/a6
0.0607
Increased risk of cancer Byproduct of drinking water disinfection
Total Trihalomethanes (TTHMs)
<!– none7

–>n/a6

0.0807
Liver, kidney or central nervous system problems; increased risk of cancer Byproduct of drinking water disinfection

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Inorganic Chemicals
Contaminant MCLG1
(mg/L)2
MCL or TT1
(mg/L)2
Potential Health Effects from Ingestion of Water Sources of Contaminant in Drinking Water
Antimony
0.006
0.006
Increase in blood cholesterol; decrease in blood sugar Discharge from petroleum refineries; fire retardants; ceramics; electronics; solder
Arsenic
07
0.010
as of 01/23/06
Skin damage or problems with circulatory systems, and may have increased risk of getting cancer Erosion of natural deposits; runoff from orchards, runoff from glass & electronicsproduction wastes
Asbestos
(fiber >10 micrometers)
7 million fibers per liter
7 MFL
Increased risk of developing benign intestinal polyps Decay of asbestos cement in water mains; erosion of natural deposits
Barium
2
2
Increase in blood pressure Discharge of drilling wastes; discharge from metal refineries; erosion of natural deposits
Beryllium
0.004
0.004
Intestinal lesions Discharge from metal refineries and coal-burning factories; discharge from electrical, aerospace, and defense industries
Cadmium
0.005
0.005
Kidney damage Corrosion of galvanized pipes; erosion of natural deposits; discharge from metal refineries; runoff from waste batteries and paints
Chromium (total)
0.1
0.1
Allergic dermatitis Discharge from steel and pulp mills; erosion of natural deposits
Copper
1.3
TT8;
Action Level=1.3
Short term exposure: Gastrointestinal distressLong term exposure: Liver or kidney damage

People with Wilson’s Disease should consult their personal doctor if the amount of copper in their water exceeds the action level

Corrosion of household plumbing systems; erosion of natural deposits
Cyanide (as free cyanide)
0.2
0.2
Nerve damage or thyroid problems Discharge from steel/metal factories; discharge from plastic and fertilizer factories
Fluoride
4.0
4.0
Bone disease (pain and tenderness of the bones); Children may get mottled teeth Water additive which promotes strong teeth; erosion of natural deposits; discharge from fertilizer and aluminum factories
Lead
zero
TT8;
Action Level=0.015
Infants and children: Delays in physical or mental development; children could show slight deficits in attention span and learning abilitiesAdults: Kidney problems; high blood pressure Corrosion of household plumbing systems; erosion of natural deposits
Mercury (inorganic)
0.002
0.002
Kidney damage Erosion of natural deposits; discharge from refineries and factories; runoff from landfills and croplands
Nitrate (measured as Nitrogen)
10
10
Infants below the age of six months who drink water containing nitrate in excess of the MCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue-baby syndrome. Runoff from fertilizer use; leaching from septic tanks, sewage; erosion of natural deposits
Nitrite (measured as Nitrogen)
1
1
Infants below the age of six months who drink water containing nitrite in excess of the MCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue-baby syndrome. Runoff from fertilizer use; leaching from septic tanks, sewage; erosion of natural deposits
Selenium
0.05
0.05
Hair or fingernail loss; numbness in fingers or toes; circulatory problems Discharge from petroleum refineries; erosion of natural deposits; discharge from mines
Thallium
0.0005
0.002
Hair loss; changes in blood; kidney, intestine, or liver problems Leaching from ore-processing sites; discharge from electronics, glass, and drug factories
Organic Chemicals
Contaminant MCLG1
(mg/L)2
MCL or TT1
(mg/L)2
Potential Health Effects from Ingestion of Water
Sources of Contaminant in Drinking Water
Acrylamide
zero
TT9

Nervous system or blood problems; increased risk of cancer

Added to water during sewage/wastewater treatment
Alachlor
zero
0.002

Eye, liver, kidney or spleen problems; anemia; increased risk of cancer

Runoff from herbicide used on row crops
Atrazine
0.003
0.003

Cardiovascular system or reproductive problems

Runoff from herbicide used on row crops
Benzene
zero
0.005

Anemia; decrease in blood platelets; increased risk of cancer

Discharge from factories; leaching from gas storage tanks and landfills
Benzo(a)pyrene (PAHs)
zero
0.0002

Reproductive difficulties; increased risk of cancer

Leaching from linings of water storage tanks and distribution lines
Carbofuran
0.04
0.04

Problems with blood, nervous system, or reproductive system

Leaching of soil fumigant used on rice and alfalfa
Carbon
tetrachloride
zero
0.005

Liver problems; increased risk of cancer

Discharge from chemical plants and other industrial activities
Chlordane
zero
0.002

Liver or nervous system problems; increased risk of cancer

Residue of banned termiticide
Chlorobenzene
0.1
0.1

Liver or kidney problems

Discharge from chemical and agricultural chemical factories
2,4-D
0.07
0.07

Kidney, liver, or adrenal gland problems

Runoff from herbicide used on row crops
Dalapon
0.2
0.2

Minor kidney changes

Runoff from herbicide used on rights of way
1,2-Dibromo-3-chloropropane (DBCP)
zero
0.0002

Reproductive difficulties; increased risk of cancer

Runoff/leaching from soil fumigant used on soybeans, cotton, pineapples, and orchards
o-Dichlorobenzene
0.6
0.6

Liver, kidney, or circulatory system problems

Discharge from industrial chemical factories
p-Dichlorobenzene
0.075
0.075

Anemia; liver, kidney or spleen damage; changes in blood

Discharge from industrial chemical factories
1,2-Dichloroethane
zero
0.005

Increased risk of cancer

Discharge from industrial chemical factories
1,1-Dichloroethylene
0.007
0.007

Liver problems

Discharge from industrial chemical factories
cis-1,2-Dichloroethylene
0.07
0.07

Liver problems

Discharge from industrial chemical factories
trans-1,2-Dichloroethylene
0.1
0.1

Liver problems

Discharge from industrial chemical factories
Dichloromethane
zero
0.005

Liver problems; increased risk of cancer

Discharge from drug and chemical factories
1,2-Dichloropropane
zero
0.005

Increased risk of cancer

Discharge from industrial chemical factories
Di(2-ethylhexyl) adipate
0.4
0.4

Weight loss, liver problems, or possible reproductive difficulties.

Discharge from chemical factories
Di(2-ethylhexyl) phthalate
zero
0.006

Reproductive difficulties; liver problems; increased risk of cancer

Discharge from rubber and chemical factories
Dinoseb
0.007
0.007

Reproductive difficulties

Runoff from herbicide used on soybeans and vegetables
Dioxin (2,3,7,8-TCDD)
zero
0.00000003

Reproductive difficulties; increased risk of cancer

Emissions from waste incineration and other combustion; discharge from chemical factories
Diquat
0.02
0.02

Cataracts

Runoff from herbicide use
Endothall
0.1
0.1

Stomach and intestinal problems

Runoff from herbicide use
Endrin
0.002
0.002

Liver problems

Residue of banned insecticide
Epichlorohydrin
zero
TT9

Increased cancer risk, and over a long period of time, stomach problems

Discharge from industrial chemical factories; an impurity of some water treatment chemicals
Ethylbenzene
0.7
0.7

Liver or kidneys problems

Discharge from petroleum refineries
Ethylene dibromide
zero
0.00005

Problems with liver, stomach, reproductive system, or kidneys; increased risk of cancer

Discharge from petroleum refineries
Glyphosate
0.7
0.7

Kidney problems; reproductive difficulties

Runoff from herbicide use
Heptachlor
zero
0.0004

Liver damage; increased risk of cancer

Residue of banned termiticide
Heptachlor epoxide
zero
0.0002

Liver damage; increased risk of cancer

Breakdown of heptachlor
Hexachlorobenzene
zero
0.001

Liver or kidney problems; reproductive difficulties; increased risk of cancer

Discharge from metal refineries and agricultural chemical factories
Hexachlorocyclopentadiene
0.05
0.05

Kidney or stomach problems

Discharge from chemical factories
Lindane
0.0002
0.0002

Liver or kidney problems

Runoff/leaching from insecticide used on cattle, lumber, gardens
Methoxychlor
0.04
0.04

Reproductive difficulties

Runoff/leaching from insecticide used on fruits, vegetables, alfalfa, livestock
Oxamyl (Vydate)
0.2
0.2

Slight nervous system effects

Runoff/leaching from insecticide used on apples, potatoes, and tomatoes
Polychlorinated
biphenyls (PCBs)
zero
0.0005

Skin changes; thymus gland problems; immune deficiencies; reproductive or nervous system difficulties; increased risk of cancer

Runoff from landfills; discharge of waste chemicals
Pentachlorophenol
zero
0.001

Liver or kidney problems; increased cancer risk

Discharge from wood preserving factories
Picloram
0.5
0.5

Liver problems

Herbicide runoff
Simazine
0.004
0.004

Problems with blood

Herbicide runoff
Styrene
0.1
0.1

Liver, kidney, or circulatory system problems

Discharge from rubber and plastic factories; leaching from landfills
Tetrachloroethylene
zero
0.005

Liver problems; increased risk of cancer

Discharge from factories and dry cleaners
Toluene
1
1

Nervous system, kidney, or liver problems

Discharge from petroleum factories
Toxaphene
zero
0.003

Kidney, liver, or thyroid problems; increased risk of cancer

Runoff/leaching from insecticide used on cotton and cattle
2,4,5-TP (Silvex)
0.05
0.05

Liver problems

Residue of banned herbicide
1,2,4-Trichlorobenzene
0.07
0.07

Changes in adrenal glands

Discharge from textile finishing factories
1,1,1-Trichloroethane
0.20
0.2

Liver, nervous system, or circulatory problems

Discharge from metal degreasing sites and other factories
1,1,2-Trichloroethane
0.003
0.005

Liver, kidney, or immune system problems

Discharge from industrial chemical factories
Trichloroethylene
zero
0.005

Liver problems; increased risk of cancer

Discharge from metal degreasing sites and other factories
Vinyl chloride
zero
0.002

Increased risk of cancer

Leaching from PVC pipes; discharge from plastic factories
Xylenes (total)
10
10

Nervous system damage

Discharge from petroleum factories; discharge from chemical factories

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Radionuclides
Contaminant MCLG1
(mg/L)2
MCL or TT1
(mg/L)2
Potential Health Effects from Ingestion of Water Sources of Contaminant in Drinking Water
Alpha particles
none7
———-
zero
15 picocuries per Liter (pCi/L)
Increased risk of cancer Erosion of natural deposits of certain minerals that are radioactive and may emit a form of radiation known as alpha radiation
Beta particles and photon emitters
none7
———-
zero
4 millirems per year
Increased risk of cancer Decay of natural and man-made deposits ofcertain minerals that are radioactive and may emit forms of radiation known as photons and beta radiation
Radium 226 and Radium 228 (combined)
none7
———-
zero
5 pCi/L
Increased risk of cancer Erosion of natural deposits
Uranium
zero

30 ug/L
as of 12/08/03

Increased risk of cancer, kidney toxicity Erosion of natural deposits

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Notes From EPA WEB PAGE: http://www.epa.gov/safewater/contaminants/index.html#mcls

1 Definitions:
Maximum Contaminant Level (MCL) – The highest level of a contaminant that is allowed in drinking water. MCLs are set as close to MCLGs as feasible using the best available treatment technology and taking cost into consideration. MCLs are enforceable standards.
Maximum Contaminant Level Goal (MCLG) – The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety and are non-enforceable public health goals.
Maximum Residual Disinfectant Level (MRDL) – The highest level of a disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants.
Maximum Residual Disinfectant Level Goal (MRDLG) – The level of a drinking water disinfectant below which there is no known or expected risk to health. MRDLGs do not reflect the benefits of the use of disinfectants to control microbial contaminants.
Treatment Technique – A required process intended to reduce the level of a contaminant in drinking water.

2 Units are in milligrams per liter (mg/L) unless otherwise noted. Milligrams per liter are equivalent to parts per million.

3 EPA’s surface water treatment rules require systems using surface water or ground water under the direct influence of surface water to (1) disinfect their water, and (2) filter their water or meet criteria for avoiding filtration so that the following contaminants are controlled at the following levels:

  • Cryptosporidium: (as of1/1/02 for systems serving >10,000 and 1/14/05 for systems serving <10,000) 99% removal.
  • Giardia lamblia: 99.9% removal/inactivation
  • Viruses: 99.99% removal/inactivation
  • Legionella: No limit, but EPA believes that if Giardia and viruses are removed/inactivated, Legionella will also be controlled.
  • Turbidity: At no time can turbidity (cloudiness of water) go above 5 nephelolometric turbidity units (NTU); systems that filter must ensure that the turbidity go no higher than 1 NTU (0.5 NTU for conventional or direct filtration) in at least 95% of the daily samples in any month. As of January 1, 2002, turbidity may never exceed 1 NTU, and must not exceed 0.3 NTU in 95% of daily samples in any month.
  • HPC: No more than 500 bacterial colonies per milliliter.
  • Long Term 1 Enhanced Surface Water Treatment (Effective Date: January 14, 2005); Surface water systems or (GWUDI) systems serving fewer than 10,000 people must comply with the applicable Long Term 1 Enhanced Surface Water Treatment Rule provisions (e.g. turbidity standards, individual filter monitoring, Cryptosporidium removal requirements, updated watershed control requirements for unfiltered systems).
  • Long Term 2 Enhanced Surface Water Treatment Rule (Effective Date: January 4, 2006) – Surface water systems or GWUDI systems must comply with the additional treatment for Cryptosporidium specified in this rule based on their Cryptosporidium bin classification calculated after the completion of source water monitoring.
  • Filter Backwash Recycling; The Filter Backwash Recycling Rule requires systems that recycle to return specific recycle flows through all processes of the system’s existing conventional or direct filtration system or at an alternate location approved by the state.

4 more than 5.0% samples total coliform-positive in a month. (For water systems that collect fewer than 40 routine samples per month, no more than one sample can be total coliform-positive per month.) Every sample that has total coliform must be analyzed for either fecal coliforms or E. coli if two consecutive TC-positive samples, and one is also positive for E.coli fecal coliforms, system has an acute MCL violation.

5 Fecal coliform and E. coli are bacteria whose presence indicates that the water may be contaminated with human or animal wastes. Disease-causing microbes (pathogens) in these wastes can cause diarrhea, cramps, nausea, headaches, or other symptoms. These pathogens may pose a special health risk for infants, young children, and people with severely compromised immune systems.

6 Although there is no collective MCLG for this contaminant group, there are individual MCLGs for some of the individual contaminants:

  • Trihalomethanes: bromodichloromethane (zero); bromoform (zero); dibromochloromethane (0.06 mg/L): chloroform (0.07mg/L).
  • Haloacetic acids: dichloroacetic acid (zero); trichloroacetic acid (0.02 mg/L); monochloroacetic acid (0.07 mg/L). Bromoacetic acid and dibromoacetic acid are regulated with this group but have no MCLGs.

7 The MCL values are the same in the Stage 2 DBPR as they were in the Stage 1 DBPR, but compliance with the MCL is based on different calculations. Under Stage 1, compliance is based on a running annual average (RAA). Under Stage 2, compliance is based on a locational running annual average (LRAA), where the annual average at each sampling location in the distribution system is used to determine compliance with the MCLs. The LRAA requirement will become effective April 1, 2012 for systems on schedule 1, October 1, 2012 for systems on schedule 2, and October 1, 2013 for all remaining systems.

8 Lead and copper are regulated by a Treatment Technique that requires systems to control the corrosiveness of their water. If more than 10% of tap water samples exceed the action level, water systems must take additional steps. For copper, the action level is 1.3 mg/L, and for lead is 0.015 mg/L.

9 Each water system must certify, in writing, to the state (using third-party or manufacturer’s certification) that when acrylamide and epichlorohydrin are used in drinking water systems, the combination (or product) of dose and monomer level does not exceed the levels specified, as follows:

  • Acrylamide = 0.05% dosed at 1 mg/L (or equivalent)
  • Epichlorohydrin = 0.01% dosed at 20 mg/L (or equivalent)

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National Secondary Drinking Water Regulations

National Secondary Drinking Water Regulations (NSDWRs or secondary standards) are non-enforceable guidelines regulating contaminants that may cause cosmetic effects (such as skin or tooth discoloration) or aesthetic effects (such as taste, odor, or color) in drinking water. EPA recommends secondary standards to water systems but does not require systems to comply. However, states may choose to adopt them as enforceable standards.

List of National Secondary Drinking Water Regulations
Contaminant
Secondary Standard
Aluminum
0.05 to 0.2 mg/L
Chloride
250 mg/L
Color
15 (color units)
Copper
1.0 mg/L
Corrosivity
noncorrosive
Fluoride
2.0 mg/L
Foaming Agents
0.5 mg/L
Iron
0.3 mg/L
Manganese
0.05 mg/L
Odor
3 threshold odor number
pH
6.5-8.5
Silver
0.10 mg/L
Sulfate
250 mg/L
Total Dissolved Solids
500 mg/L
Zinc
5 mg/L


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Unregulated Contaminants

This list of contaminants which, at the time of publication, are not subject to any proposed or promulgated national primary drinking water regulation (NPDWR), are known or anticipated to occur in public water systems, and may require regulations under SDWA. For more information check out the list, or vist the Drinking Water Contaminant Candidate List (CCL) web site.

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This page has been republished on this site to make it easier to find the list of Drinking Water Contaminants.

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