Drinking Water 

National Primary Drinking Water Standards

The National Primary Drinking Water Standards are quality standards for public drinking water, promulgated by the United States Environmental Protection Agency under the authority of the Safe Drinking Water Act. There are three types of standards: Primary Standards, which are enforceable health based standards; Secondary Standards, which are non-enforceable aesthetic based standards, and Unregulated Contaminants, which are being studied for possible future regulation. Information includes contaminant names, analytical technique used by the Arkansas Department of Health, Maximum Contaminant Level (MCL) or Treatment Technique (TT) (used instead of Maximum Contaminant Level for certain contaminants), and links to the US Environmental Protection Agency's web site for health effects and other technical information. The index site for drinking water information is http://www.epa.gov/safewater/dwh/health.html

Primary Standards

Secondary Contaminants
Unregulated Contaminants

Microbiological Contaminants

Microbiological Contaminants MCL./TT
Total Coliform <5% positive, (>40 samples/mo)
1 colony, (<40 samples/mo)
Fecal Coliform/E. Coli Present
Turbidity

TT
<0.5 NTU in at least 95% of measurements
No reading >5.0 NTU

Girdia Lambia TT
Viruses (enteric) TT
Legionella TT
Standard Plate Count TT

Notes:

TCR = Total Coliform Rule
TT = Treatment Technique

 

Inorganic Contaminants

Primary Inorganic Contaminants (Enforceable) MCL./mg/l) EPA Method Detection Limit (mg/l)
Antimony 0.006 0.003
Arsenic 0.05 0.001
Asbestos

 7 MFL

0.01 MFL
Barium 2 0.002
Beryllium 0.004 0.002
Cadmium 0.005 0.0001
Chromium 0.1 0.001
Copper** 1.3 0.001
Cyanide 0.2 0.005
Fluoride 4.0 1.0
Lead** 0.015 0.001
Mercury 0.002 0.0002
Nitrate (as nitrogen) 10 0.05
Nitrite (as nitrogen) 1 0.05
Combined Nitrate/Nitrite 10 0.05
Selenium 0.05 0.002
Thallium 0.002 0.001

Notes:

* MFL = Millions of Fibers (>10m m) per Liter. Analyzed by Transmission Electron Microscopy method: "Analytical Method

** No MCL. Action Level based upon 90 percentile sample results.

Organic Contaminants

Primary Organic Contaminants (Enforceable) MCL./mg/l) EPA Detection Limit (mg/l)**
1,1,1-Trichloroethane 0.2 0.0005
1,1,2-Trichloroethane 0.005 0.0005
1,1-Dichloroethylene

0.007 

0.0005
1,2,4-Trichlorobenzene 0.07 0.0005
1,2-Dichloroethane 0.005 0.0005
1,2-Dichloropropane 0.005 0.0005
2,3,7,8-TCDD (Dioxin) 0.00000003 0.000000011
2,4,5-TP (Silvex) 0.05 0.00044
2,4-D 0.07 0.00022
Acrylamide  * TT N/A
Alachlor 0.002 0.00044
Aldicarb 0.003  
Aldicarb Sulfoxide    
Aldicarb Sulfone    
Atrazine 0.003 0.00022
Benzene 0.005 0.0005
Carbofuran 0.04 0.00198
Carbon Tetrachloride 0.005 0.0005
Chlordane 0.002 0.00044
cis-1,2-Dichlorethylene 0.07 0.0005
Dalapon 0.2 0.0022
Di(ethylhexyl)-adipate 0.4 0.00132
Di(ethylhexyl)-phthalate 0.006 0.00132
Dibromochloropropane (DBCP) 0.0002 0.000044
Dichloromethane (Methylene Chloride) 0.005 0.0005
Dinoseb 0.007 0.00044
Diquat 0.02 0.00088
Endothall 0.1 0.0198
Endrin 0.002 0.000022
Epichlorohydrin  * TT N/A
Ethylbenzene 0.7 0.0005
Ethylene Dibromide 0.00005 0.000022
Glyphosate 0.7 0.0132
Heptachlor 0.0004 0.000088
Heptachlor Epoxide 0.0002 0.000044
Hexachlorobenzene 0.001 0.00022
Hexachlorocyclo-pentadiene 0.05 0.00022
Lindane 0.0002 0.000044
Methoxychlor 0.04 0.00022
Monochlorobenzene (Chlorobenzene) 0.1 0.0005
o-Dichlorbenzene 0.6 0.0005
Oxyml 0.2 0.0044
PAH's (Benzo(a)pyrene) 0.0002 0.000044
PCB's (as decachlorobiphenyl) * 0.0005 0.00022
p-Dichlorobenzene 0.075 0.0005
Pentachlorophenol 0.001 0.000088
Picloram 0.5 0.00022
Simazine 0.004 0.000154
Styrene 0.1 0.0005
Tetrachloroethylene 0.005 0.0005
Toluene 1 0.0005
Total Trihalomethanes 0.100 0.0005
Toxaphene 0.003 0.0022
trans-1,2-Dichloroethylene 0.1 0.0005
Trichloroethylene 0.005 0.0005
Vinyl Chloride 0.002 0.0005
Xylenes 10 0.005

Radiochemical Contaminants

Primary Radiochemical Contaminants (Enforceable) MCL EPA Detect Limit
Gross Alpha (excluding radon and uranium) 15 pCi/l 3 pCi/l
Radium 226 & 228 combined 5 pCi/l 1 pCi/l
Gross Beta 4 mrem/yr* 4 pCi/l
Tritium

20,000

1,000
Strontium-90 8 2

Notes:
pCi/l = picocuries per year
mrem/yr = millirem per year

Secondary Contaminants

Secondary Contaminants (Non-Enforceable) Recommended Limit
milligrams/liter
Aluminum 0.05 - 0.2
Chloride 250
N/AColor

15 Color Units

Corrosivity Non-corrosive
Fluoride 2.0
Foaming Agents 0.5
Iron 0.3
Manganese 0.05
Odor 3 Threshold Odor Number
pH 6.5 - 8.5
Silver 0.1
Sulfate 250
Total Dissolved Solids 500
Zinc 5

Unregulated Contaminants

Unregulated Organic Contaminants (Not-Enforceable) MCL (mg/l)
3-Hydroxycarbofuran N/A
Aldrin N/A
Butachlor

 N/A

Carbaryl N/A
Dicamba N/A
Dieldrin N/A
Methomyl N/A
Metolachlor N/A
Metribuzin N/A
Propachlor N/A
Bromobenzene N/A
Bromodichloromethane N/A
Bromoform N/A
Bromomethane N/A
Chlorodibromethane N/A
Chloroform N/A
Chloroethane N/A
Chloromethane N/A
o-Chlorotoluene N/A
p-Chlorotoluene N/A
m-Dichlorobenzene N/A
1,1-Dichloroethane N/A
1,3-Dichloropropane N/A
2,2-Dichloropropane N/A
1,1-Dichloropropene N/A
1,3-Dichloropropene N/A
1,1,1,2-Tetrachloroethane N/A
1,1,2,2-Tetrachloroethane N/A
1,2,3-Trichloropropane N/A