Nebraska Administrative Code
Topic - HEALTH AND HUMAN SERVICES SYSTEM
Title 179 - PUBLIC WATER SYSTEMS
Chapter 12 - CONTROL OF LEAD AND COPPER
Section 179-12-010 - MONITORING REQUIREMENTS FOR WATER QUALITY PARAMETERS

Universal Citation: 179 NE Admin Rules and Regs ch 12 ยง 010

Current through September 17, 2024

All large systems, and all small and medium-size systems that exceed the lead or copper action level must monitor water quality parameters in addition to lead and copper in accordance with 179 NAC 12-010. These monitoring requirements are summarized in the table at the end of 179 NAC 12-010.

010.01 General Requirements

12-010.01A Sample Collection Methods
12-010.01A1 Tap samples must be representative of water quality throughout the distribution system taking into account the number of persons served, the different sources of water, the different treatment methods employed by the system, and seasonal variability. Tap sampling under 179 NAC 12-010 is not required to be conducted at taps targeted for lead and copper sampling under 179 NAC 12-009.01. [Note: Systems may find it convenient to conduct tap sampling for water quality parameters at sites used for coliform sampling.]

12-010.01A2 Samples collected at the entry point(s) to the distribution system must be from locations representative of each source after treatment. If a system draws water from more than one source and the sources are combined before distribution, the system must sample at an entry point to the distribution system during periods of normal operating conditions (i.e., when water is representative of all sources being used).

12-010.01B Number of Samples
12-010.01B1 Systems must collect two tap samples for applicable water quality parameters during each monitoring period specified under 179 NAC 12-010.02 to 12-010.05 from the following number of sites.

System Size(# People Served)

# of Sites For Water Quality Parameters

>100,000

25

10, 001-100,000

10

3,301 to 10,000

3

501 to 3,300

2

101 to 500

1

<=100

1

12-010.01B2 Except as provided in 179 NAC 12-010.03C, systems must collect two samples for each applicable water quality parameter at each entry point to the distribution system during each monitoring period specified in 179 NAC 12-010.02. During each monitoring period specified in 179 NAC 12-010.03 to 12-010.05, systems must collect one sample for each applicable water quality parameter at each entry point to the distribution system.

010.02 Initial Sampling

All large water systems must measure the applicable water quality parameters as specified below at taps and at each entry point to the distribution system during each six-month monitoring period specified in 179 NAC 12-009.04A. All small and medium-size systems must measure the applicable water quality parameters at the locations specified below during each six-month monitoring period specified in 179 NAC 12-009.04A during which the system exceeds the lead or copper action level.

12-010.02A At taps:
1. pH;

2. Alkalinity;

3. Orthophosphate, when an inhibitor containing a phosphate compound is used;

4. Silica, when an inhibitor containing a silicate compound is used;

5. Calcium;

6. Conductivity; and

7. Water temperature.

12-010.02B At each entry point to the distribution system: all of the applicable parameters listed in 179 NAC 12-010.02A.

010.03 Monitoring after Installation of Corrosion Control

Any large system which installs optimal corrosion control treatment pursuant to 179 NAC 12-004.04 item 4 must measure the water quality parameters at the locations and frequencies specified below during each six-month monitoring period specified in 179 NAC 12-009.04B 1. Any small or medium-size system which installs optimal corrosion control treatment must conduct such monitoring during each six-month monitoring period specified in 179 NAC 12-009.04B 2 in which the system exceeds the lead or copper action level.

12-010.03A At taps, two samples for:
1. pH;

2. Alkalinity;

3. Orthophosphate, when an inhibitor containing a phosphate compound is used;

4. Silica, when an inhibitor containing a silicate compound is used;

5. Calcium, when calcium carbonate stabilization is used as part of corrosion control.

12-010.03B Except as provided in 179 NAC 12-010.03C, at each entry point to the distribution system, one sample every two weeks (bi-weekly) for:
1. pH;

2. When alkalinity is adjusted as part of optimal corrosion control, a reading of the dosage rate of the chemical used to adjust alkalinity, and the alkalinity concentration; and

3. When a corrosion inhibitor is used as part of optimal corrosion control, a reading of the dosage rate of the inhibitor used, and the concentration of orthophosphate or silica (whichever is applicable).

12-010.03C Any ground water system can limit entry point sampling described in 179 NAC 12-010.03B to those entry points that are representative of water quality and treatment conditions throughout the system. If water from untreated ground water sources mixes with water from treated ground water sources, the system must monitor for water quality parameters both at representative entry points receiving treatment and representative entry points receiving no treatment. Prior to the start of any monitoring under 179 NAC 12-010.03C, the system must provide to the Director written information identifying the selected entry points and documentation, including information on seasonal variability, sufficient to demonstrate that the sites are representative of water quality and treatment conditions throughout the system.

010.04 Monitoring after the Director Specifies Water Quality Parameter Values for Optimal Corrosion Control

After the Director specifies the values for applicable water quality control parameters reflecting optimal corrosion control treatment under 179 NAC 12-005.06, all large systems must measure the applicable water quality parameters in accordance with 179 NAC 12010.03 and determine compliance with the requirements of 179 NAC 12-005.07 every six months with the first six-month period to begin on the date the Director specifies the optimal values under 179 NAC 12-005.06. Any small or medium-size system must conduct such monitoring during each six-month period specified in 179 NAC 12-010.04 in which the system exceeds the lead or copper action level. For any such small and medium-size system that is subject to a reduced monitoring frequency pursuant to 179 NAC 12-009.04D at the time of the action level exceedance, the end of the applicable six-month period under 12-010.04 must coincide with the end of the applicable monitoring period under 179 NAC 12-009.04D. Compliance with the Director-designated optimal water quality parameter values must be determined as specified under 179 NAC 12-005.07.

010.05 Reduced Monitoring

12-010.05A Any water system that maintains the range of values for the water quality parameters reflecting optimal corrosion control treatment during each of two consecutive six-month monitoring periods under 179 NAC 12-010.04 must continue monitoring at the entry point(s) to the distribution system as specified in 179 NAC 12-010.03B. The system may collect two tap samples for applicable water quality parameters from the following reduced number of sites during each six-month monitoring period.

System Size (# People Served)

Reduced # of Sites for Water Quality Parameters

>100,000

10

10,001 to 100,000

7

3,301 to 10,000

3

501 to 3,300

2

101 to 500

1

<=100

1

12-010.05B Systems Maintaining Range of Water Quality Parameters Reflecting Optimal Corrosion Control
12-010.05B1 Any water system that maintains the range of values for the water quality parameters reflecting optimal corrosion control treatment specified by the Director under 179 NAC 12-005.06 during three consecutive years of monitoring may reduce the frequency with which it collects the number of tap samples for applicable water quality parameters specified in 179 NAC 12-010.05A from every six months to annually. Any water system that maintains the range of values for the water quality parameters reflecting optimal corrosion control treatment specified by the Director under 179 NAC 12-005.06 during three consecutive years of annual monitoring under 179 NAC 12-010.05B1 may reduce the frequency with which it collects the number of tap samples for applicable water quality parameters specified in 179 NAC 12-010.05A from annually to every three years.

12-010.05B2 A water system may reduce the frequency with which it collects tap samples for applicable water quality parameters specified in 179 NAC 12-010.05A to every three years if it demonstrates during two consecutive monitoring periods that its tap water lead level at the 90th percentile is less than or equal to the PQL for lead specified in 179 NAC 12-012.01A item 2, that its tap water copper level at the 90th percentile is less than or equal to 0.65 mg/L for copper in 179 NAC 12-003.01B, and that it also has maintained the range of values for the water quality parameters reflecting optimal corrosion control treatment specified by the Director under 179 NAC 12-005.06.

12-010.05C A water system that conducts sampling annually must collect these samples evenly throughout the year so as to reflect seasonal variability.

12-010.05D Any water system subject to reduced monitoring frequency that fails to operate at or above the minimum value or within the range of values for the water quality parameters specified by the Director under 179 NAC 12-005.06 for more than nine days in any six-month period specified in 179 NAC 12-005.07 must resume distribution system tap water sampling in accordance with the number and frequency requirements in 179 NAC 12-010.04. The system may resume annual monitoring for water quality parameters at the tap at the reduced number of sites specified in 179 NAC 12-010.05A after it has completed two subsequent consecutive six-month rounds of monitoring that meet the criteria of 179 NAC 12-010.05A and/or may resume triennial monitoring for water quality parameters at the tap at the reduced number of sites after it demonstrates through subsequent rounds of monitoring that it meets the criteria of either 179 NAC 12-010.05B1 or 12-010.05B2.

010.06 Additional Monitoring by Systems

The results of any monitoring conducted in addition to the minimum requirements of 179 NAC 12-010 will be considered by the system and the Director in making any determinations (i.e., determining concentrations of water quality parameters) under 179 NAC 12-010 or 12-005.

SUMMARY OF MONITORING REQUIREMENTS FOR WATER QUALITY PARAMETERS1

Monitoring Period

Parameters2

Location

Frequency

Initial Monitoring

pH, alkalinity, orthophosphate or silica3, calcium, conductivity, temperature.

Taps and at entry point(s) to distribution system

Every six months

After Installation of Corrosion Control

pH, alkalinity, orthophosphate or silica3, calcium4

Taps

Every six months

pH, alkalinity, dosage rate and concentration (if alkalinity adjusted as part of corrosion control), inhibitor dosage rate and inhibitor residual5

Entry point(s) to distribution system6

No less frequently than every two weeks

After Director Specifies Parameter Values For Optimal Corrosion Control

pH, alkalinity, orthophosphate or silica3, calcium4.

Taps

Every six months

pH, alkalinity dosage rate and concentration (if alkalinity adjusted as part of corrosion control), inhibitor dosage rate and inhibitor residual5.

Entry point(s) to distribution system6

No less frequently than every two weeks

Reduced Monitoring

pH, alkalinity, orthophosphate or silica3, calcium4.

Taps

Every six months; annually7 or every three years8;; reduced number of sites

pH, alkalinity dosage rate and concentration (if alkalinity adjusted as part of corrosion control), inhibitor dosage rate and inhibitor residual5.

Entry point(s) to distribution system6

No less frequently than every 2 weeks

1 Table is for illustrative purposes; consult the text of 179 NAC 12-010 for precise regulatory requirements.

2 Small and medium-size systems have to monitor for water quality parameters only during monitoring periods in which the system exceeds the lead or copper action level.

3 Orthophosphate must be measured only when an inhibitor containing a phosphate compound is used. Silica must be measured only when an inhibitor containing a silicate compound is used.

4 Calcium must be measured only when calcium carbonate stabilization is used as part of corrosion control.

5 Inhibitor dosage rates and inhibitor residual concentrations (orthophosphate or silica) must be measured only when an inhibitor is used.

6 Ground water systems may limit monitoring to representative locations throughout the system.

7 Water systems may reduce frequency of monitoring for water quality parameters at the tap from every six months to annually if they have maintained the range of values for water quality parameters reflecting optimal corrosion control during three consecutive years of monitoring.

8 Water systems may further reduce the frequency of monitoring for water quality parameters at the tap from annually to once every three years if they have maintained the range of values for water quality parameters reflecting optimal corrosion control during three consecutive years of annual monitoring. Water systems may accelerate to triennial monitoring for water quality parameters at the tap if they have maintained 90th percentile lead levels less than or equal to 0.005 mg/L, 90th percentile copper levels less than or equal to 0.65 mg/L, and the range of water quality parameters designated by the Director under 179 NAC 12-005.06 as representing optimal corrosion control during two consecutive 6-month monitoring periods.

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