Nebraska Administrative Code
Topic - HEALTH AND HUMAN SERVICES SYSTEM
Title 179 - PUBLIC WATER SYSTEMS
Chapter 3 - MONITORING AND ANALYTICAL REQUIREMENTS
Section 179-3-005 - INORGANIC CHEMICAL SAMPLING AND ANALYTICAL REQUIREMENTS
Current through September 17, 2024
Community water systems and non-transient, non-community water systems must conduct monitoring to determine compliance with the maximum contaminant levels specified in 179 NAC 2-002.04A in accordance with 179 NAC 3-005. Transient, non-community water systems must conduct monitoring to determine compliance with the nitrate and nitrite maximum contaminant levels in 179 NAC 2-002.04A (12), (13), and (14) in accordance with 179 NAC 3-005. Monitoring must be conducted as follows.
005.01 Sampling Sites and Protocol
NOTE: For the purpose of 179 NAC 3-005.01 item 2, surface water systems include systems with a combination of surface and ground sources.
DETECTION LIMITS FOR INORGANIC CONTAMINANTS
Contaminant |
MCL (mg/L) |
Methodology |
Detection Limit (mg/L) |
Antimony |
0.006 |
Atomic Absorption; Furnace |
0.003 |
Atomic Absorption; Platform |
0.00085 |
||
ICP-Mass Spectrometry |
0.0004 |
||
Hydride- Atomic Absorption |
0.001 |
||
Arsenic |
0.0106 |
Atomic Absorption; Furnace Atomic Absorption; Platform - |
0.001 |
Stabilized Temperature |
0.00057 |
||
Atomic Absorption; Gaseous Hydride |
0.001 |
||
ICP-Mass Spectrometry |
0.00148 |
||
Asbestos |
7 MFL1 |
Transmission Electron Microscopy |
0.01 MFL |
Barium |
2 |
Atomic Absorption; furnace technique |
0.002 |
Atomic Absorption; direct aspiration |
0.1 |
||
Inductively Coupled Plasma |
0.002, ( 0.001) |
||
Beryllium |
0.004 |
Atomic Absorption; Furnace |
0.0002 |
Atomic Absorption; Platform |
0.000025 |
||
Inductively Coupled Plasma2 |
0.0003 |
||
ICP-Mass Spectrometry |
0.0003 |
||
Cadmium |
0.005 |
Atomic Absorption; furnace technique |
0.0001 |
Inductively Coupled Plasma |
0.001 |
||
Chromium |
0.1 |
Atomic Absorption; furnace technique |
0.001 |
Inductively Coupled Plasma |
0.007 ( 0.001) |
||
Cyanide |
0.2 |
Distillation, Spectrophotometric3 |
0.02 |
Distillation, Automated, Spectrophotometric3 |
0.005 |
||
Distillation, Selective Electrode3,4 |
0.05 |
||
Distillation, Amenable, Spectrophotometric4 |
0.02 |
||
UV, Distillation, Spectrophotometric9 Micro Distillation, Flow Injection, |
0.0005 |
||
Spectrophotometric3 |
0.0006 |
||
Ligand Exchange with Amperometry4 |
0.0005 |
||
Mercury |
0.002 |
Manual Cold Vapor Technique |
0.0002 |
Automated Cold Vapor Technique |
0.0002 |
||
Nickel |
xl |
Atomic Absorption; Furnace |
0.001 |
Atomic Absorption; Platform |
0.00065 |
||
Inductively Coupled Plasma2 |
0.005 |
||
ICP-Mass Spectrometry |
0.0005 |
||
Nitrate |
10 (as N) |
Manual Cadmium Reduction |
0.01 |
Automated Hydrazine Reduction |
0.01 |
||
Automated Cadmium Reduction |
0.05 |
||
Ion Selective Electrode |
1 |
||
Ion Chromatography |
0.01 |
||
Capillary Ion Electrophoresis |
0.076 |
||
Nitrite |
1 (as N) |
Spectrophotometric |
0.01 |
Automated Cadmium Reduction |
0.05 |
||
Manual Cadmium Reduction |
0.01 |
||
Ion Chromatography |
0.004 |
||
Capillary Ion Electrophoresis |
0.103 |
||
Selenium |
0.05 |
Atomic Absorption; furnace |
0.002 |
Atomic Absorption; gaseous hydride |
0.002 |
||
Thallium |
0.002 |
Atomic Absorption; Furnace |
0.001 |
Atomic Absorption; Platform |
0.00075 |
||
ICP-Mass Spectrometry |
0.0003 |
1 MFL = million fibers per liter >10µm.
2 Using a 2X preconcentration step as noted in Method 200.7. Lower MDLs may be achieved when using a 4X preconcentration.
3 Screening method for total cyanides.
4 Measures "free" cyanides when distillation, digestion, or ligand exchange is omitted.
5 Lower MDLs are reported using stabilized temperature graphite furnace atomic absorption.
6 The value for arsenic is effective January 23, 2006. Until then, the MCL is 0.05 mg/L.
7 The MDL reported for EPA Method 200.9 (Atomic Absorption; Platform-Stabilized Temperature) was determined using a 2x concentration step during sample digestion. The MDL determined for samples analyzed using direct analyses (i.e., no sample digestion) will be higher. Using multiple depositions, EPA 200.9 is capable of obtaining an MDL of 0.0001 mg/L.
8 Using selective ion monitoring, EPA Method 200.8 (ICP-MS) is capable of obtaining an MDL of 0.0001 mg/L.
9Measures total cyanides when UV-digestor is used, and "free" cyanides when UV-digestor is bypassed.
005.02 Asbestos Sampling
The frequency of monitoring conducted to determine compliance with the maximum contaminant level for asbestos must be conducted as follows:
005.03 Monitoring for Inorganic Chemicals (Except Asbestos, Nitrate, and Nitrite)
The frequency of monitoring conducted to determine compliance with the maximum contaminant levels in 179 NAC 2-002.04A for antimony, arsenic, barium, beryllium, cadmium, chromium, cyanide, fluoride, mercury, nickel, selenium, and thallium is as follows.
005.04 Monitoring Requirements for Nitrate
The owners of all public water systems (community; non-transient, non-community; and transient, non-community systems) must monitor to determine compliance with the maximum contaminant levels for nitrate.
3-00 5.04A Base Nitrate Sampling: Owners of community and non-transient, non-community water systems must monitor for nitrate as follows. Ground water entry points must be monitored annually beginning January 1, 1995 except as required in 179 NAC 3-005.04E; surface water entry points must be monitored quarterly beginning January 1, 1995.
3-00 5.04B Increased Nitrate Sampling Frequency: For community and non-transient non-community water systems; the monitoring frequency for ground water entry points must be quarterly following any one sample in which the concentration is greater than or equal to 5.0 milligrams per liter of nitrate as nitrogen. The monitoring frequency will reduce to annual after four consecutive quarterly samples are reliably and consistently less than the MCL except as required in 179 NAC 3-005.04E. In this case, annual monitoring must be done during the quarter which previously resulted in the highest analytical result.
3-00 5.04C Surface Water Reduced Nitrate Sampling Frequency: For community and non-transient, non-community water systems; the monitoring of surface water entry points will be reduced to annual if all analytical results from four consecutive quarters are less than 5.0 mg/L (as nitrogen) except as required in 179 NAC 3-005.04E. In this case, annual monitoring must be done during a quarter which previously resulted in the highest analytical result. Surface water entry points will return to quarterly monitoring if any one sample is greater than or equal to 5.0 mg/L (as nitrogen).
005.05 Monitoring Requirements for Nitrite
The owners of all public water systems (community; non-transient, non-community; and transient, non-community systems) must monitor to determine compliance with the maximum contaminant level for nitrite in 179 NAC 2-002.04A.
005.06 Confirmation Samples
005.07 Director's Designation of Increased Sampling Frequency
The Director may require more frequent monitoring than specified in 179 NAC 3-005.02 through 3-005.05 or may require confirmation samples for positive and negative results at his/her discretion.
005.08 Public water systems may apply to the Director to conduct more frequent monitoring than the minimum monitoring frequencies specified.
005.09 Compliance Calculations
Compliance with 179 NAC 2-002.04A must be determined based on the analytical result(s) obtained at each sampling point.
005.10 State Designated Sampling Schedules
Each public water system owner must monitor at the time designated by the Director during each compliance period.
005.11 Analytical Methods for Inorganic Analysis
Contaminant |
Preservative1 |
Container2 |
Time3 |
Antimony |
HNO3 |
P or G |
6 months |
Arsenic |
Conc HNO3 to pH<2 |
P or G |
6 months |
Asbestos |
4°C |
P or G |
48 hours4 |
Barium |
HNO3 |
P or G |
6 months |
Beryllium |
HNO3 |
P or G |
6 months |
Cadmium |
HNO3 |
P or G |
6 months |
Chromium |
HNO3 |
P or G |
6 months |
Cyanide |
4°C, NaOH |
P or G |
14 days |
Fluoride |
None |
P or G |
1 month |
Mercury |
HNO3 |
P or G |
28 days |
Nickel |
HNO3 |
P or G |
6 months |
Nitrate |
4°C |
P or G |
48 hours5 |
Nitrate-Nitrite6 |
H2SO4 |
P or G |
28 days |
Nitrite |
4°C |
P or G |
48 hours |
Selenium |
HNO3 |
P or G |
6 months |
Thallium |
HNO3 |
P or G |
6 months |
1For cyanide determinations samples must be adjusted with sodium hydroxide to pH 12 at the time of collection. When chilling is indicated, the sample must be shipped and stored at 4°C or less. Acidification of nitrate or metals samples may be with a concentrated acid or a dilute (50% by volume) solution of the applicable concentrated acid. Acidification of samples for metals analysis is encouraged and allowed at the laboratory rather than at the time of sampling provided the shipping time and other instructions in Section 8.3 of EPA Methods 200.7 or 200.8 or 200.9 are followed.
2P = plastic, hard or soft; G = glass, hard or soft.
3In all cases, samples should be analyzed as soon after collection as possible. Follow additional (if any) information on preservation, containers or holding times that is specified in method.
4Instructions for containers, preservation procedures and holding times as specified in Method 100.2 must be adhered to for all compliance analyses including those conducted with Method 100.1
5If the sample is chlorinated, the holding time for an unacidified sample kept at 4°C is extended to 14 days.
6Nitrate-Nitrite refers to a measurement of total nitrate.
Contaminant |
Acceptance Limit |
Antimony |
± 30% at >= 0.006 mg/L |
Arsenic |
± 30% at >= 0.003 mg/L effective January 23, 2006 |
Asbestos |
2 standard deviations based on study statistics |
Barium |
± 15% at >= 0.15 mg/L |
Beryllium |
± 15% at >= 0.001 mg/L |
Cadmium |
± 20% at >= 0.002 mg/L |
Chromium |
± 15% at >= 0.01 mg/L |
Cyanide |
± 25% at >= 0.1 mg/L |
Fluoride |
± 10% at >=1 to 10 mg/L |
Mercury |
± 30% at >= 0.0005 mg/L |
Nickel |
± 15% at >= 0.01 mg/L |
Nitrate |
± 10% at >= 0.4 mg/L |
Nitrite |
± 15% at >= 0.4 mg/L |
Selenium |
± 20% at >= 0.01 mg/L |
Thallium |
± 30% at >= 0.002 mg/L |
005.12 If the result of an analysis made under 179 NAC 3-005 indicates that the level of arsenic exceeds the maximum contaminant level, the owner of the public water system must initiate three additional analyses at the sampling point within one month.
005.13 When the average of four analyses made pursuant to 179 NAC 3-005.12, rounded to the same number of significant figures as the maximum contaminant level for the substance in question, exceeds the maximum contaminant level, the owner of the system must notify the Department pursuant to 179 NAC 5 and give notice to the public pursuant to 179 NAC 4. Monitoring after public notification must be at a frequency designated by the Director and must continue until the maximum contaminant level has not been exceeded in two successive samples or until a monitoring schedule as a condition to a variance, exemption or enforcement action becomes effective.
005.14 The provisions of 179 NAC 3-005.12 and 3-005.13 notwithstanding, compliance with the maximum contaminant level for nitrate will be determined on the basis of the mean of two analyses. When a level exceeding the maximum contaminant level for nitrate is found, a second analysis must be initiated within 24 hours, and if the mean of the two analyses exceeds the maximum contaminant level, the supplier of water must report his findings to the Department pursuant to 179 NAC 5 and must notify the public pursuant to 179 NAC 4.