Nebraska Administrative Code
Topic - HEALTH AND HUMAN SERVICES SYSTEM
Title 179 - PUBLIC WATER SYSTEMS
Chapter 2 - PUBLIC WATER SUPPLY SYSTEMS
Section 179-2-002 - DRINKING WATER STANDARDS AND TREATMENT TECHNIQUES
Current through March 20, 2024
2-002.01 SCOPE AND AUTHORITY: These regulations establish drinking water standards, treatment techniques, best available technologies (BATs) and compliance technologies for public water systems. The authority is found in Neb. Rev. Stat. §§ 71-5301 to 71-5313.
2-002.02 DEFINITIONS
Best Available Technology or BAT means the best technology, treatment techniques, or other means which the U.S. Environmental Protection Agency finds, after examination for efficacy under field conditions and not solely under laboratory conditions, are available (taking cost into consideration). For the purposes of setting MCLs for synthetic organic chemicals, any BAT must be at least as effective as granular activated carbon.
GAC10 means granular activated carbon filter beds with an empty-bed contact time of 10 minutes based on average daily flow and a carbon reactivation frequency of every 180 days, except that the reactivation frequency for GAC10 used as a best available technology for compliance with Title 179 NAC 24 MCLs under 179 NAC 2-002.04E2a(1) is 120 days.
GAC20 means granular activated carbon filter beds with an empty-bed contact time of 20 minutes based on average daily flow and a carbon reactivation frequency of every 240 days.
Maximum Contaminant Level (MCL) means the maximum permissible level of a contaminant in water which is delivered to any user of a public water system.
2-002.03 DRINKING WATER STANDARDS AND TREATMENT TECHNIQUES: The basis for the establishment of maximum contaminant levels is based either upon potential acute health effects over a short length of time of exposure or chronic health effects over a long length of time of exposure.
2-002.04 Maximum Contaminant Levels
CONTAMINANT |
MCL (mg/L) |
(1) Antimony |
0.006 |
(2) Asbestos (fibers >10 µm) |
7 million fibers/Liter |
(3) Arsenic |
0.010 |
(4) Barium |
2 |
(5) Beryllium |
0.004 |
(6) Cadmium |
0.005 |
(7) Chromium total |
0.10 |
(8) Cyanide (as free cyanide) |
0.2 |
(9) Fluoride* |
4.0 |
(10) Mercury |
0.002 |
(11) Nickel |
0.1 |
(12) Nitrate (as Nitrogen) |
10 |
(13) Nitrite (as Nitrogen) |
1 |
(14) Total Nitrate and Nitrite (as Nitrogen) |
10 |
(15) Selenium |
0.05 |
(16) Sodium |
500.0 |
(17) Thallium |
0.002 |
*Community water systems experiencing fluoride levels above 2.0 milligrams per liter must notify the public as required in 179 NAC 4-010.
CONTAMINANT |
MCL (mg/L) |
(1) Vinyl chloride |
0.002 |
(2) Benzene |
0.005 |
(3) Carbon tetrachloride |
0.005 |
(4) 1,2-Dichloroethane |
0.005 |
(5) Trichloroethylene |
0.005 |
(6) para-Dichlorobenzene |
0.075 |
(7) 1,1-Dichloroethylene |
0.007 |
(8) 1,1,1-Trichloroethane |
0.2 |
(9) cis-1,2-Dichloroethylene |
0.07 |
(10) 1,2-Dichloropropane |
0.005 |
(11) Ethylbenzene |
0.7 |
(12) Monochlorobenzene |
0.1 |
(13) o-Dichlorobenzene |
0.6 |
(14) Styrene |
0.1 |
(15) Tetrachloroethylene |
0.005 |
(16) Toluene |
1 |
(17) trans-1,2-Dichloroethylene |
0.1 |
(18) Xylenes (total) |
10 |
(19) Dichloromethane |
0.005 |
(20) 1,2,4-Trichlorobenzene |
0.07 |
(21) 1,1,2-Trichloroethane |
0.005 |
CONTAMINANT |
MCL (mg/L) |
(1) Alachlor |
0.002 |
(2) reserved |
|
(3) reserved |
|
(4) reserved |
|
(5) Atrazine |
0.003 |
(6) Carbofuran |
0.04 |
(7) Chlordane |
0.002 |
(8) Dibromochloropropane |
0.0002 |
(9) 2,4-D |
0.07 |
(10) Ethylene dibromide |
0.00005 |
(11) Heptachlor |
0.0004 |
(12) Heptachlor epoxide |
0.0002 |
(13) Lindane |
0.0002 |
(14) Methoxychlor |
0.04 |
(15) Polychlorinated biphenyls |
0.0005 |
(16) Pentachlorophenol |
0.001 |
(17) Toxaphene |
0.003 |
(18) 2,4,5-TP |
0.05 |
(19) Benzo[a]pyrene |
0.0002 |
(20) Dalapon |
0.2 |
0.4 |
|
0.006 |
|
(23) Dinoseb |
0.007 |
(24) Diquat |
0.02 |
(25) Endothall |
0.1 |
(26) Endrin |
0.002 |
(27) Glyphosate |
0.7 |
(28) Hexachlorobenzene |
0.001 |
(29) Hexachlorocyclopentadiene |
0.05 |
(30) Oxamyl (Vydate) |
0.2 |
(31) Picloram |
0.5 |
(32) Simazine |
0.004 |
(33) 2,3,7,8-TCDD (Dioxin) |
3 x 10-8 |
AVERAGE ANNUAL CONCENTRATIONS ASSUMED TO PRODUCE A TOTAL BODY OR ORGAN DOSE OF 4 MILLIREM PER YEAR
Radionuclide |
Critical Organ |
pCi per liter |
Tritium |
Total Body |
20,000 |
Strontium-90 |
Bone Marrow |
8 |
Disinfection Byproduct |
MCL (mg/L) |
Bromate . . . . . . . . . . . . . . . . . . . . . . . . . . |
0.010 |
Chlorite . . . . . . . . . . . . . . . . . . . . . . . . . . |
1.0 |
BATs FOR BROMATE AND CHLORITE
Disinfection Byproduct |
Best Available Technology |
Bromate |
Control of ozone treatment process to reduce production of bromate. |
Chlorite |
Control of treatment processes to reduce disinfectant demand and control of disinfection treatment processes to reduce disinfectant levels. |
Disinfection byproduct |
MCL (mg/L) |
Total trihalomethanes (TTHMs) |
0.080 |
Haloacetic acids (five) (HAA5) |
0.060 |
Disinfection byproduct |
Best available technology |
Total trihalomethanes (TTHMs) and Haloacetic acids (five) (HAA5s) |
Enhanced coagulation or enhanced softening or GAC10, with chlorine as the primary and residual disinfectant |
Disinfection byproduct |
MCL (mg/L) |
Total trihalomethanes (TTHMs) |
0.080 |
Haloacetic acids (five) (HAA5) |
0.060 |
Disinfection byproduct |
Best available technology |
Total trihalomethanes (TTHMs) and Haloacetic acids (five) (HAA5s) |
Enhanced coagulation or enhanced softening plus GAC10, or nanofiltration with a molecular weight cutoff <=1000 Daltons; or GAC20 |
Disinfection byproduct |
Best available technology |
Total trihalomethanes (TTHMs) and Haloacetic acids (five) (HAA5s) |
Systems serving >=10,000: Improved distribution system and storage tank management to reduce residence time, plus the use of chloramines for disinfectant residual maintenance Systems serving <10,000: Improved distribution system and storage tank management to reduce residence time |
MRDLs
DISINFECTANT RESIDUAL |
MRDL (MG/L) |
Chlorine |
4.0 (as Cl2). |
Chloramines |
4.0 (as Cl2). |
Chlorine dioxide |
0.8 (as ClO2). |
2-002.05 Treatment Techniques
2-002.06 BAT (Best Available Technology): The Director hereby identifies as indicated in the table below granular activated carbon (GAC), packed tower aeration (PTA), or oxidation (OX) as the best technology treatment technique, or other means available for achieving compliance with the maximum contaminant level for organic contaminants identified in 179 NAC 2-002.04B1 and 2-002.04B2.
BAT FOR CONTAMINANTS LISTED IN 179 NAC 2-002.04B1 and 2-002.04B2
CAS NO. |
Contaminant |
GAC |
PTA |
OX |
15972-60-8 |
Alachlor |
X |
-- |
-- |
116-06-3 |
Aldicarb |
X |
-- |
-- |
1646-88-4 |
Aldicarb sulfone |
X |
-- |
-- |
1646-87-3 |
Aldicarb sulfoxide |
X |
-- |
-- |
1912-24-9 |
Atrazine |
X |
-- |
-- |
71-43-2 |
Benzene |
X |
X |
-- |
1563-66-2 |
Carbofuran |
X |
-- |
-- |
56-23-5 |
Carbon tetrachloride |
X |
X |
-- |
57-74-9 |
Chlordane |
X |
-- |
-- |
75-99-0 |
Dalapon |
X |
-- |
-- |
94-75-7 |
2,4-D |
X |
-- |
-- |
103-23-1 |
Di(2-ethylhexyl)adipate |
X |
X |
-- |
117-81-7 |
Di(2-ethylhexyl)phthalate |
X |
-- |
-- |
96-12-8 |
Dibromochloropropane (DBCP) |
X |
X |
-- |
95-50-1 |
o-Dichlorobenzene |
X |
X |
-- |
106-46-7 |
para-Dichlorobenzene |
X |
X |
-- |
107-06-2 |
1,2-Dichloroethane |
X |
X |
-- |
75-35-4 |
1,1-Dichloroethylene |
X |
X |
-- |
156-59-2 |
cis-1,2-Dichloroethylene |
X |
X |
-- |
156-60-5 |
trans-1,2-Dichloroethylene |
X |
X |
-- |
75-09-2 |
Dichloromethane |
-- |
X |
-- |
78-87-5 |
1,2-Dichloropropane |
X |
X |
-- |
88-85-7 |
Dinoseb |
X |
-- |
-- |
72-20-8 |
Endrin |
X |
-- |
-- |
100-41-4 |
Ethylbenzene |
X |
X |
-- |
106-93-4 |
Ethylene Dibromide (EDB) |
X |
X |
-- |
1071-83-6 |
Glyphosate |
-- |
-- |
X |
76-44-8 |
Heptachlor |
X |
-- |
-- |
1024-57-3 |
Heptachlor epoxide |
X |
-- |
-- |
118-74-1 |
Hexachlorobenzene |
X |
-- |
-- |
77-47-3 |
Hexachlorocyclopentadiene |
X |
X |
-- |
58-89-9 |
Lindane |
X |
-- |
-- |
72-43-5 |
Methoxychlor |
X |
-- |
-- |
108-90-7 |
Monochlorobenzene |
X |
X |
-- |
23135-22-0 |
Oxamyl (Vydate) |
X |
-- |
-- |
87-86-5 |
Pentachlorophenol |
X |
-- |
-- |
1918-02-1 |
Picloram |
X |
-- |
-- |
1336-36-3 |
Polychlorinated biphenyls (PCB) |
X |
-- |
-- |
122-34-9 |
Simazine |
X |
-- |
-- |
100-42-5 |
Styrene |
X |
X |
-- |
1746-01-6 |
2,3,7,8-TCDD (Dioxin) |
X |
-- |
-- |
127-18-4 |
Tetrachloroethylene |
X |
X |
-- |
108-88-3 |
Toluene |
X |
X |
-- |
8001-35-2 |
Toxaphene |
X |
-- |
-- |
93-72-1 |
2,4,5-TP (Silvex) |
X |
-- |
-- |
120-82-1 |
1,2,4-Trichlorobenzene |
X |
X |
-- |
71-55-6 |
1,1,1-Trichloroethane |
X |
X |
-- |
79-00-5 |
1,1,2-Trichloroethane |
X |
X |
-- |
79-01-6 |
Trichloroethylene |
X |
X |
-- |
75-01-4 |
Vinyl chloride |
-- |
X |
-- |
1330-20-7 |
Xylene |
X |
X |
-- |
2-002.07 BAT FOR INORGANIC COMPOUNDS LISTED IN 179 NAC 2-002.04A (EXCEPT FLUORIDE)
BATs FOR INORGANIC COMPOUNDS
Chemical Name |
BAT(s) |
Antimony |
2,7 |
Asbestos |
2,3,8 |
Arsenic4 |
1,2,5,6,7,9,125,6 |
Barium |
5,6,7,9 |
Beryllium |
1,2,5,6,7 |
Cadmium |
2,5,6,7 |
Chromium |
2,5,62,7 |
Cyanide |
5,7,13 |
Mercury |
21,4,61,71 |
Nickel |
5,6,7 |
Nitrate |
5,7,9 |
Nitrite |
5,7 |
Selenium |
1,23,6,7,9 |
Thallium |
1,5 |
1 BAT only if influent Hg concentrations <= 10µg/L.
2 BAT for Chromium III only.
3 BAT for Selenium IV only.
4BAT for Arsenic V. Pre-oxidation may be required to convert Arsenic III to Arsenic V.
5To obtain high removals, iron to arsenic ratio must be at least 20:1.
6Effective for the purpose of compliance on January 23, 2006.
Key to BATS in Table
1 = Activated Alumina
2 = Coagulation/Filtration (not BAT for systems <500 service connections)
3 = Direct and Diatomite Filtration
4 - Granular Activated Carbon
5 = Ion Exchange
6 = Lime Softening (not BAT for systems <500 service connections)
7 = Reverse Osmosis
8 = Corrosion Control
9 = Electrodialysis
10 = Chlorine
11 = Ultraviolet
12 = Oxidation/Filtration
13 = Alkaline Chlorination (pH >= 8.5)
2-002.08 Best Available Technologies (BATs) for Radionuclides: The Director hereby identifies as indicated in the following table the best technology available for achieving compliance with the maximum contaminant levels for combined radium-226 and -228, uranium, gross alpha particle activity, and beta particle and photon radioactivity.
BAT FOR COMBINED RADIUM-226 AND RADIUM-228, URANIUM, GROSS ALPHA PARTICLE ACTIVITY, AND BETA PARTICLE AND PHOTON RADIOACTIVITY
Contaminant |
BAT |
1. Combined radium-226 and radium-228 |
Ion exchange, reverse osmosis, lime softening |
2. Uranium |
Ion exchange, reverse osmosis, lime softening, coagulation/filtration |
3. Gross alpha particle activity (excluding radon and uranium) |
Reverse osmosis |
4. Beta particle and photon radioactivity |
Ion exchange, reverse osmosis |
2-002.09 Small Systems Compliance Technologies List for Radionuclides
LIST OF SMALL SYSTEMS COMPLIANCE TECHNOLOGIES FOR RADIONUCLIDES AND LIMITATIONS TO USE
Unit Technologies |
Limitations (See Footnotes) |
Operator Skill Level Required1 |
Raw Water Quality Range and Considerations1 |
1. Ion exchange (IE) |
a |
Intermediate |
All ground waters |
2. Point of use (POU2) IE |
b |
Basic |
All ground waters |
3. Reverse osmosis (RO) |
c |
Advanced |
Surface waters usually require pre-filtration |
4. POU2 RO |
b |
Basic |
Surface waters usually require pre-filtration |
5. Lime softening |
d |
Advanced |
All waters |
6. Green sand filtration |
e |
Basic |
|
7. Co-precipitation with barium sulfate |
f |
Intermediate to Advanced |
Ground waters with suitable water quality |
8. Electrodialysis/ electrodialysis reversal |
--- |
Basic to Intermediate |
All ground waters |
9. Pre-formed hydrous manganese oxide filtration |
g |
Intermediate |
All ground waters |
10. Activated alumina |
a, h |
Advanced |
All ground waters; competing anion concentrations may affect regeneration frequency |
11. Enhanced coagulation/filtration |
i |
Advanced |
Can treat a wide range of water qualities |
1 National Research Council (NRC), Safe Water from Every Tap: Improving Water Service to Small Communities. National Academy Press. Washington, D.C. 1997.
2 A POU, or "point-of-use" technology is a treatment device installed at a single tap used for the purpose of reducing contaminants in drinking water at that one tap. POU devices are typically installed at the kitchen tap. See the April 21, 2000 Federal Register Notice of Data Availability (NODA) at http://www.epa.gov/safewater/radws/frnoda.pdf for more details.
Limitations Footnotes: Technologies for Radionuclides
a The regeneration solution contains high concentrations of the contaminant ions. Disposal options should be carefully considered before choosing this technology.
b When POU devices are used for compliance, programs for long-term operation, maintenance, and monitoring must be provided by water utility to ensure proper performance.
c Reject water disposal options should be carefully considered before choosing this technology. See other RO limitations described in the SWTR compliance technologies table.
d The combination of variable source water quality and the complexity of the water chemistry involved may make this technology too complex for small surface water systems.
e Removal efficiencies can vary depending on water quality.
f This technology may be very limited in application to small systems. Since the process requires static mixing, detention basins, and filtration, it is most applicable to systems with sufficiently high sulfate levels that already have a suitable filtration treatment train in place.
g This technology is most applicable to small systems that already have filtration in place.
h Handling of chemicals required during regeneration and pH adjustment may be too difficult for small systems without an adequately trained operator.
i Assumes modification to a coagulation/filtration process already in place.
2-002.10 Small System Compliance Technologies (SSCTs) for Arsenic: The Director identifies in the following table the affordable technology, treatment technique, or other means available to systems serving 10,000 individuals or fewer for achieving compliance with the maximum contaminant level for arsenic effective for the purpose of compliance as of January 23, 2006:
SMALL SYSTEM COMPLIANCE TECHNOLOGIES (SSCTs)1 FOR ARSENIC2
Small system compliance technology |
Affordable for listed small system categories3 |
Activated Alumina (centralized) |
All size categories |
Activated Alumina (Point-of-use)4 |
All size categories |
Coagulation/Filtration5 |
501-3,300, 3,301-10,000 |
Coagulation-assisted Microfiltration |
501-3,300, 3,301-10,000 |
Electrodialysis reversal6 |
501-3,300, 3,301-10,000 |
Enhanced coagulation/filtration |
All size categories |
Enhanced lime softening (pH>10.5) |
All size categories |
Ion Exchange |
All size categories |
Lime Softening5 |
501-3,300, 3,301-10,000 |
Oxidation/Filtration7 |
All size categories |
Reverse Osmosis (centralized)6 |
501-3,300, 3,301-10,000 |
Reverse Osmosis (Point-of-Use)4 |
All size categories |
1 Section 1412(b)(4)(E)(ii) of the federal Safe Drinking Water Act (SDWA) specifies that SSCTs must be affordable and technically feasible for small systems.
2SSCTs for Arsenic V. Pre-oxidation may be required to convert Arsenic III to Arsenic V.
3The federal SDWA specifies three categories of small systems: (i) those serving 25 or more, but fewer than 501, (ii) those serving more than 500, but fewer than 3,301, and (iii) those serving more than 3,300, but fewer than 10,001.
4When POU or POE devices are used for compliance, programs to ensure proper long-term operation, maintenance, and monitoring must be provided by the water system to ensure adequate performance.
5Unlikely to be installed solely for arsenic removal. May require pH adjustment to optimal range if high removals are needed.
6Technologies to reject a large volume of water-may not be appropriate for areas where water quantity may be an issue.
7To obtain high removals, iron to arsenic ratio must be at least 20:1.
2-002.11 Compliance Technologies by System Size Category for Radionuclide Drinking Water Standards
COMPLIANCE TECHNOLOGIES BY SYSTEM SIZE CATEGORY FOR RADIONUCLIDE DRINKING WATER STANDARDS
Contaminant |
Compliance technologies1 for system size categories (population served) |
||
25-500 |
501-3,300 |
3,300-10,000 |
|
Combined radium-226 and radium-228 |
1,2,3,4,5,6,7,8,9 |
1,2,3,4,5,6,7,8,9 |
1,2,3,4,5,6,7,8,9 |
Gross alpha particle activity |
3,4 |
3,4 |
3,4 |
Beta particle activity and photon activity |
1,2,3,4 |
1,2,3,4 |
1,2,3,4 |
Uranium |
1,2,4,10,11 |
1,2,3,4,5,10,11 |
1,2,3,4,5,10,11 |
1 Note: Numbers correspond to those technologies found listed in the unit technologies column in the table in 179 NAC 2-002.09.