Drinking Water Standards

National Primary Drinking Water Standards Primary (Health Related) Inorganic Contaminants

Contaminants

MCLG 

MCL 

WQA Recommended Treatment Methods 

Potential Health Effects from Ingestion of Water 

Sources of Contaminant in Drinking Water

Antimony

0.006 mg/L

0.006 mg/L

-Coagulation/Filtration
-Submicron Filtration
-Reverse Osmosis
-Ultrafiltration
-Distillation

-Cancer

-Fire retardants
-Ceramics
-Electronics
-Fireworks
-Solder
Arsenic (+3)

0.05 mg/L

0.05 mg/L
(Interim
Standard)

-Chemical Oxidation/Disinfection
-Reverse Osmosis
-Distillation		-Skin Damage
-Nervous system toxicity		-Natural deposits
-Smelters
-Glass
-Electronic wastes
-Orchards
Arsenic (+5)  -Coagulation/Fiiltration
-Submicron Filtration
-Anion Exchange
-Activated Alumina
-Reverse Osmosis
-Distillation
-Electrodialysis		  
Arsenic (organic complexed)  -Activated Carbon  
Asbestos (fibers > 10 µm)7 MFL7 MFP
(million fibers
per iter, >10 µm)

-Coagulation/Filtration
-Submicron Filtration
-Reverse Osmosis
-Ultrafiltration
-Distillation

-Cancer
-Nervous system toxicity

-Natural deposits
-Asbestos cement in water systems

Barium

2.0 mg/L

2.0 mg/L

-Cation Exchange
-Reverse Osmosis
-Distillation
-Electrodialysis		-Circulatory system effects
-Nervous system toxicity		-Natural deposits
-Pigments
-Epoxy sealants
-Spent coal

Beryllium

0.004 mg/L0.004 mg/L-Coagulation/Filtration
-Submicron Filtration
-Activated Carbon
-Activated Alumina
-Cation Exchange
-Reverse Osmosis
-Distillation
-Electrodialysis		-Bone damage
-Lung Damage		-Electrical aerospace, defense industries

Cadmium

0.005 mg/L0.005 mg/L-Coagulation/Filtration
-Submicron Filtration
-Cation Exchange
-Distillation		-Kidney Effects-Galvanized pipe corrosion
-Natural deposits
-Batteries
-Paints

Choromium (+3)

0.1 mg/L

0.1 mg/L (total chromium)

-Coagulation/Filtration
-Cation Exchange
-Reverse Osmosis
-Distillation
-Electrodialysis

-Liver Disorders
-Kidney Disorders
-Circulatory disorders		-Natural deposits
-Mining
-Electroplating
-Pigments

Chromium (+6)

Same As above  

-Anion Exchange
-Reverse Osmosis
-Distillation
-Electrodialysis

  
Chromium (organic complexes)Same As above 

-Activated Carbon

  

Copper

1.3 mg/L1.3 mg/L (action level)-Cation Exchange (20%-90%)
-Reverse Osmosis
-Distillation
-Electrodialysis		-Gastrointestinal irritation-Natural/industrial deposits
-Wood preservatives
-Plumbing

Cyanide

0.2 mg/L0.2 mg/L-Chemical Oxidation/Disinfection
-Anion Exchange (20%-90%)
-Reverse Osmosis
-Distillation
-Electrodialysis		-Thyroid Damage
-Nervous system damage		-Electroplating
-Steel
-Plastics
-Mining
-Fertilizer

Fluoride

4.0 mg/L

4.0 mg/L

-Activated Alumina
-Bone Char
-Reverse Osmosis
-Distillation
-Electrodialysis

-Skeletal & dental florosis-Natural deposits
-Fertilizer
-Aluminum industries
-Water additive

Lead

zero

0.015 mg/L (action level)

-Cation Exchange(20%-90%)
-Coagulation/Filtration
-Submicron Filtration/Activated Carbon
-Reverse Osmosis
-Distillation
-Electrodialysis

-Kidney damage
-Nervous system damage		-Natural/industrial deposits
-Plumbing
-Solder
-Brass alloy faucets

Mercury (+2)

0.002 mg/L

0.002 mg/L (total mercury)

-Cation Exchange(20%-90%)
-Coagulation/Filtration
-Submicron Filtration/Activated Carbon
-Reverse Osmosis
-Distillation
-Electrodialysis		-Kidney disorders
-Nervous system damage		-Crop runoff
-Natural deposits
-Batteries
-Electrical switches

Mercury (HgCl3)

  -Anion Exchange(20%-90%)
-Reverse Osmosis
-Distillation
-Electrodialysis		  

Mercury (organic complexes)

  -Activated Carbon  

Nickel

0.1 mg/L0.1 mg/L-Cation Exchange(20%-90%)
-Reverse Osmosis
-Distillation
-Electrodialysis		-Heart damage
-Liver damage		-Metal alloys
-Electroplating
-Batteries
-Chemical production

Nitrate (as nitrogen)

10 mg/L10 mg/L

-Anion Exchange
-Reverse Osmosis (sensitive to pressure)
-Distillation
-Electrodialysis

-Methemolglobulinemia-Animal waste
-Fertilizer
-Natural deposits
-Septic tanks
-Sewage

Nitrite (as nitrogen)

1 mg/L

1 mg/L-Chemical Oxidation
-Anion Exchange
-Reverse Osmosis
-Distillation
-Electrodialysis		-Methemolglobulinemia

Same as Nitrate;rapidly converted to Nitrate

Selenium (+4)

0.05 mg/L

 		0.05 mg/L (total selenium)-Coagulation/Filtration
-Submicron Filtration/Activated Carbon
-Anion Exchange
-Activated Alumina
-Reverse Osmosis
-Distillation
-Electrodialysis

-Liver damage

-Natural deposits
-Mining
-Smelting
-Coal/Oil combustion

Selenium (+6)

  

-Anion Exchange
-Activated Alumina
-Reverse Osmosis
-Distillation
-Electrodialysis

  

Sulfate

500 mg/L (proposed standard)500 mg/L (proposed standard)-Anion Exchange
-Activated Alumina
-Reverse Osmosis
-Distillation
-Electrodialysis

-Diarrhea

-Natural deposits

Thallium

0.0005 mg/L (proposed standard)0.002 mg/L (proposed standard)

-Cation Exchange
-Activated Alumina
-Distillation

-Kidney, liver, brain, intestinal damage

-Electronics
-Drugs
-Alloys
-Glass

National Primary Drinking Water Standards Primary (Health Related) Organic Contaminants

Contaminants

MCLG, mg/L

MCL, mg/L

Treatment Methods

Acrylamide

zero

0.0005 (action level)Control of water treatment chemicals and surfaces in contact with water
Adipates (diethylhexyl)

0.4

0.4

Activated Carbon
Aeration

Alachlor

zero

0.002

Activated Carbon

Aldicarb

0.007 (P)*

0.007 (P)*

Activated Carbon

Aldicarb sulfone

0.007 (P)*

0.007 (P)*

Activated Carbon

Aldicarb sulfoxide

0.007 (P)*0.007 (P)*Activated Carbon

Altrazine

0.003

0.003

Activated Carbon

Benz(a)anthracene (PAH)

zero (P)*

0.0001 (P)*

Activated Carbon

Benzene

zero

0.005

Activated Carbon
Aeration

Benzo(a)pyrene (PAH)

zero

0.0002

Activated Carbon

Benzo(b)fluroanthene

zero (P)*

0.0002 (P)*

Activated Carbon

Benzo(k)fluoranthene (PAH)

zero (P)*

0.0002 (P)*

Activated Carbon

Butyl benzyl phthalate (PAE)

zero (P)*

0.1 (P)*

Activated Carbon

Carbofuran

0.04

0.04

Activated Carbon

Carbon tetrachloride

zero

0.005  

Activated Carbon
Aeration

Chlordane

zero

0.002

Activated Carbon

Chrysene (PAH)

zero (P)*

0.0002 (P)*

Activated Carbon

2,4-D

0.07

0.07

Activated Carbon

Dalapon

0.20.2

Activated Carbon

Di[2-ethylhexyl]adipate

0.40.4

Activated Carbon

Dibenza(a,h)anthracene (PAH)

zero (P)*

0.0003 (P)*

Activated Carbon

Dibromochloropropane (DBCP)

zero

0.0002

Activated Carbon
Aeration

Dichlorobenzene (ortho-)

0.6

0.6

Activated Carbon
Aeration

Dichlorobenzene (meta-)

0.60.6

Activated Carbon
Aeration

Dichlorobenzene (para-)

0.075

0.075Activated Carbon
Aeration

Dichloroethane (1,2-)

zero

0.005

Activated Carbon
Aeration

Dichloroethylene (1,1-)

0.007

0.007Activated Carbon
Aeration
Dichloroethylene (cis-1,2-)

0.07

0.07

Activated Carbon
Aeration
Dichloroethylene (trans-1,2-)

0.1

0.1

Activated Carbon
Aeration
Dichloromethane (methylene chloride)zero0.005Aeration

Dichloropropane (1,2-)

zero

0.005

Activated Carbon
Aeration

Diethylhexyl phthalate (PAE)

zero  

0.006Activated Carbon

Dinoseb

zero

0.006

Activated Carbon

Diquat

0.02

0.02

Activated Carbon

Endothall

0.10.1

Activated Carbon

Endrin

0.002

0.002

Activated Carbon

Epichlorohydrinzero

0.002 (action level)

Control of water treatment chemicals and surfaces in contact with water

Ethylbenzene

0.7

0.7

Activated Carbon
Aeration

Ethylene Dibromide (EDB)

zero

0.00005

Activated Carbon
Aeration

Glyphosphate

0.70.7

Activated Carbon

Heptachlor

zero

0.0004

Activated Carbon

Heptachlor epoxide

zero

0.0002

Activated Carbon

Hexachlorocyclopentadiene

0.05

0.05

Activated Carbon
Aeration

Indenol (1,2,3-c,d)pyrene (PAH)

zero (P)*

0.0004 (P)*

Activated Carbon

Lindane

0.0002

0.0002

Activated Carbon

Methoxychlor

0.04

0.04

Activated Carbon

Monochlorobenzene

0.1

0.1

Activated Carbon
Aeration

Oxamyl (vydate)

0.2

0.2

Activated Carbon

Pentachlorophenol

zero

0.001

Activated Carbon

Picloram

0.5

0.5

Activated Carbon

Polychlorinated byphenyls (PCBs)

zero

0.0005Activated Carbon

Simarzine

0.004

0.004

Activated Carbon

Styrene

0.1

0.1

Activated Carbon
Aeration

2,3,7,8-TCDD (dioxin)

zero

3X10-8

Activated Carbon

Tetrachloroethylene

zero

0.005

Activated Carbon
Aeration

Toluene

1.

1.Activated Carbon
Aeration

Toxaphene

zero

0.003

Activated Carbon

2,4,5-TP (silvex)

0.05

0.05

Activated Carbon

Trichlorobenzene (1,2,4)

0.07

0.07

Activated Carbon
Aeration

Trichloroethane (1,1,1-)

0.2

0.2

Activated Carbon
Aeration

Trichloroethane (1,1,2-)

0.003

0.005

Activated Carbon
Aeration

Trichloroethylene

zero

0.005

Activated Carbon
Aeration

Trihalomethanes (THMs)

  • Chloroform
  • Bromodichloromethane
  • Dibromochloromethane
  • Bromoform
zero

0.100

Activated Carbon
Aeration
Ultrafiltration (20%-90%)
Reverse Osmosis (20%-90%)

Vinyl chloride

zero

0.002

Aeration

Xylenes (total)

10.10.

Activated Carbon
Aeration

(P)* = Proposed Standard
MCLG = Maximum Contaminant Level Goal established at the level at which no known or anticipated adverse effects on the health of persons occur and which allows an adequate margin of safety; expressed in milligrams per liter unless otherwise specified.
MCL = Maximum Contaminant Level established as close to the MCLG as feasible taking into consideration costs and treatment techniques applicable at public water systems; expressed in milligrams per liter unless otherwise specified.

 

National Secondary Drinking Water Regulations

Recognized Treatment Techniques for meeting the National Secondary Drinking Water Regulations with the Application of Point-Of-Use Systems

"The National Secondary Drinking Water regulations control contaminants in drinking water that primarily affect the aesthetic qualities relating to the public acceptance of drinking water. The regulations are not federally enforceable but are intended as guidelines for the states" (40 CFR Section 143.3)

For simplicity, WQA uses the term Point-Of-Use (POU) when referring to both treatment at the tap and for whole house treatment.

Except for instances of contamination through inhalation or dermal adsorption, the WQA notes that in-home treatment of drinking and cooking water only is often the most economical and preferred method of choice for reducing these drinking water aesthetic contaminants. Of course, the particular contaminant found in the water will determine the appropriate treatment technique.

The recognized treatment methods listed here reflect the fact that point-of-use systems on the market today may differ widely in their effectiveness to treat any specific contaminant. Anyone contemplating use of such point-of-use equipment for a specific application or purpose should make their selection only after careful investigation of the performance capabilities. As part of the installation procedure, the performance of the system should be verified through an appropriate water analysis. In addition, the product water should be monitored periodically to verify performance.

It is the general consensus of the manufacturers and sellers of the point-of-use systems employing the listed techniques that, if these systems are defect free, properly applied and installed, and maintained strictly according to the manufacturers' installation and maintenance instructions, they may be considered for use in meeting the requirements of the National Secondary Drinking Water Regulations (SDWR).

Contaminant

SMCL, mg/L

Treatment Methods

Aluminum (AL +3 )

0.05 to 0.2 depending on case-by-case circumstances

Cation Exchange
Reverse Osmosis
Distillation
Electrodialysis

Chloride (C1 -1 )

250

Reverse Osmosis
Distillation
Anion Exchange
Electrodialysis

Color

15 color units

Anion Exchange
Activated Carbon
Filtration
Chlorination

Reverse Osmosis
Distillation
Ozonation
Activated Alumina

Copper (Cu +2 )

1.0

Reverse Osmosis
Distillation
Cation Exchange (20%-90%)
Electrodialysis

Corrosivity

Non-corrosive

Calcite or Calcite/Magnesium Oxide (Magnesia)
(5 to 1) Filter to raise pH
Soda Ash Chemical Feed
Polyphosphate Feed
Sodium Silicate Feed
Reduce TDS via Reverse Osmosis (partial, split stream treatment)
Coatings
Insulating Unions

Fluoride (Fl -1 )

2.0

Activated Alumina
Bone Char
Reverse Osmosis
Distillation
Electrodialysis

Foaming agents (MBAS)
(methylene blue active substances)

0.5

Chlorination
Activated Carbon
Ozonation

Reverse Osmosis
Distillation

Iron (Fe +2)
(ferric iron)

0.3

Filtration(oxidizing filters)
Cation Exchange
Reverse Osmosis*
Pressure Areation/Filtration
Chlorination - Precipitation/Filtration

Distillation
Electrodialysis

Iron (Fe +3 )

0.05

Filtration

*Ferrous Iron (clear water iron) is readily converted to ferric iron (red water iron) in the presence of any air or oxidizing material; precipitating ferric iron must be prevented to avoid fouling and interference with effective reverse osmosis membrane rejection.

Manganese (Mn +2)
(ferric iron)

0.5

Filtration(oxidizing filters)
Cation Exchange
Reverse Osmosis*
Distillation
Pressure Areation/Filtration
Chlorination - Precipitation/Filtration
Electrodialysis

Manganese (Mn +4 )

 

Filtration

*manganese must be maintained in the soluble manganous (Mn +2) to avoid fouling and interference with effective reverse osmosis membrane rejection.

Odor

3 threshold odor number

Activated Carbon
Aeration
Oxidation

Note: Chlorine and hydrogen sulfide are examples of odors that may e reduced by the treatment methods suggested.

pH

6.5-8.5

pH may be increased by alkalies and may be decreased by acids
Ion Exchange
Neutralizing Filter (Calcite, Magnesia)

Silver (Ag +1)

0.1

Coagulation/Filtration
Submicron Filtration/Activated Carbon
Ion Exchange (Anion or Cation depending on complexed Ion Species)

Sulfate (SO 4 -2)

250

Reverse Osmosis
Distillation
Anion Exchange
Electrodialysis

Total dissolved solids (TDS)

500

Reverse Osmosis
Distillation
Deionzation by Ion Exchange (Cation/Anion in two bed or mixed bed)
Electrodialysis

Zinc (Zn +2)

5

Reverse Osmosis
Distillation
Cation Exchange
Electrodialysis