Section 179-16-004 - ANALYTICAL REQUIREMENTS004.01 General 16-004.01A Systems must use only the analytical method(s) specified in 40 CFR 141.131(a)(1) through (b)(1) or their equivalent as approved by the United States Environmental Protection Agency (EPA) to demonstrate compliance with the requirements of 179 NAC 16, 179 NAC 23 and 179 NAC 24..16-004.02B Analysis under 179 NAC 16 for disinfection byproducts must be conducted by the Department Public Health Environmental Laboratory (certified by EPA) or a laboratory that has entered into an agreement with the Department Laboratory except as specified under 179 NAC 20. To receive certification to conduct analyses for the DBP contaminants in 179 NAC 2-002.04E, 179 NAC 16-008, 179 NAC 23 and 179 NAC 24 the laboratory must: 1. Analyze performance evaluation (PE) samples that are acceptable to the Department at least once during each consecutive 12 month period by each method for which the laboratory desires certification.2. The laboratory must achieve quantitative results on the PE sample analyses that are within the following acceptance limits: Disinfection Byproduct | Acceptancelimits (percent of true value) | Comments |
TTHM Chloroform Bromodichloromethane Dibromochloromethane Bromoform | ±20 ±20 ±20 ±20 | Laboratory must meet all 4 individual THM acceptance limits in order to successfully pass a PE sample for TTHMs |
HAA5 Monochloroacetic Acid Dichloroacetic Acid Trichloroacetic Acid Monobromoacetic Acid Dibromoacetic Acid | +40 +40 +40 +40 +40 | Laboratory must meet the acceptance limits for 4 out of 5 of the HAA5 compounds in order to successfully pass a PE sample for HAA5 |
Chlorite | ±30 |
Bromate | +30 |
3. Report quantitative data for concentrations at least as low as the ones listed in the following table for all DBP samples analyzed for compliance with 179 NAC 2-002.04E, 179 NAC 16-008, and 179 NAC 23 and 179 NAC 24. Disinfection Byproduct | Minimum reporting level (mg/L) 1 | Comments |
TTHM 2 Chloroform Bromodichloromethane Dibromochloromethane Bromoform | 0.0010 0.0010 0.0010 0.0010 |
HAA5 2 Monochloroacetic Acid Dichloroacetic Acid Trichloroacetic Acid Monobromoacetic Acid Dibromoacetic Acid | 0.0020 0.0010 0.0010 0.0010 0.0010 |
Chlorite Bromate | 0.020 0.0050 or 0.0010 | Applicable to monitoring as prescribed in 179 NAC 16-005.02 items 2.a(2) and 2.b. Laboratories that use EPA Methods 317.0 Revision 2.0, 326.0 or 321.8 must meet a 0.0010 mg/L MRL for bromate. |
1 The calibration curve must encompass the regulatory minimum reporting level (MRL) concentration. Data may be reported for concentrations lower than the regulatory MRL as long as the precision and accuracy criteria are met by analyzing an MRL check standard at the lowest reporting limit chosen by the laboratory. The laboratory must verify the accuracy of the calibration curve at the MRL concentration by analyzing an MRL check standard with a concentration less than or equal to 110% of the MRL with each batch of samples. The measured concentration for the MRL check standard must be ±50% of the expected value, if any field sample in the batch has a concentration less than 5 times the regulatory MRL. Method requirements to analyze higher concentration check standards and meet tighter acceptance criteria for them must be met in addition to the MRL check standard requirement.
2 When adding the individual trihalomethane or haloacetic acid concentrations to calculate the TTHM or HAA5 concentrations, respectively, a zero is used for any analytical result that is less than the MRL concentration for that DBP, unless otherwise specified by the Department.
16-004.02C A Grade I, II, III, or IV licensed water operator or a person who has been trained to take the samples must measure daily chlorite samples at the entrance to the distribution system. If a licensed operator does not take the sample, Attachment 3, which is incorporated herein by reference must be completed and sent to the Department.004.03 Disinfectant Residuals 16-004.03A Systems must measure residual disinfectant concentrations for free chlorine, combined chlorine (chloramines), and chlorine dioxide by the methods listed in 40 CFR 141.131(c) or an equivalent method approved by EPA: 16-004.03B If approved by the Department, systems may also measure residual disinfectant concentrations for chlorine, chloramines, and chlorine dioxide by using DPD colorimetric test kits.16-004.03C A Nebraska licensed Grade I, II, III, or IV operator or a person who has been trained to take the samples must measure residual disinfectant concentration. If the sample is not taken by a licensed operator, Attachment 3 to 179 NAC 16 must be completed and sent to the Department.004.04 Additional Analytical Methods : Systems required to analyze parameters not included in 179 NAC 16-004.02 and 16-004.03 must use the following methods or an equivalent method approved by EPA. The Department Laboratory (certified by EPA) or a laboratory that has entered into an agreement with the Department Laboratory must analyze for the following parameters, except that pH may be analyzed by the Department Laboratory, or a laboratory that has entered into an agreement with the Department Laboratory, or on-site by a Nebraska licensed Grade I, II, III, or IV operator or a person who has been trained on how to take the samples. If the sample is not taken by a licensed operator, Attachment 3 must be completed and sent to the Department.
1.Alkalinity: All methods allowed in 179 NAC 3-005.11A for measuring alkalinity.2.Bromide: Methods found in 40 CFR 141.131(d) (2).3.Total Organic Carbon (TOC): Methods found in 40 CFR 141.131(d) (3. Inorganic carbon must be removed from the samples prior to analysis. TOC samples may not be filtered prior to analysis. TOC samples must be acidified at the time of sample collection to achieve pH less than or equal to 2 with minimal addition of the acid specified in the method or by the instrument manufacturer. Acidified TOC samples must be analyzed within 28 days.4.Specific Ultraviolet Absorbance (SUVA): SUVA is equal to the UV absorption at 254 nm (UV254) (measured in m-1 divided by the dissolved organic carbon (DOC) concentration (measured as mg/L). In order to determine SUVA, it is necessary to separately measure UV254 and DOC. When determining SUVA, systems must use the methods stipulated in 179 NAC 16-004.04 item 4.a. to measure DOC and the method stipulated in 179 NAC 16-004.04 item 4.b. to measure UV254. SUVA must be determined on water prior to the addition of disinfectants/oxidants by the system. DOC and UV254 samples used to determine a SUVA value must be taken at the same time and at the same location. SUVA may be calculated using DOC and UV254 data as found in EPA Method 415.3 Rev. 1.2, "Determination of Total Organic Carbon and Specific UV Absorbance at 254 nm in Source Water and Drinking Water," August 2009. EPA/600/R-09/122. Available at http://www.epa.gov/nerlcwww/ordmeth.htm.. a.Dissolved Organic Carbon (DOC): Methods in CFR 141.131(d)(4)(i). DOC samples must be filtered through a 0.45 µm pore-diameter filter as soon as practical after sampling, not to exceed 48 hours. After filtration, DOC samples must be acidified to achieve pH less than or equal to 2 with minimal addition of the acid specified in the method or by the instrument manufacturer. Acidified DOC samples must be analyzed within 28 days of sample collection. Inorganic carbon must be removed from the samples prior to analysis. Water passed through the filter prior to filtration of the sample must serve as the filtered blank. This filtered blank must be analyzed using procedures identical to those used for analysis of the samples and must meet the following criteria: DOC< 0.5 mg/L.b.Ultraviolet Absorption at 254 nm (UV254): Methods in CFR 141.131(d)(4)(ii). UV absorption must be measured at 253.7 nm (may be rounded off to 254 nm). Prior to analysis, UV254 samples must be filtered through a 0.45 µm pore-diameter filter. The pH of UV254 samples may not be adjusted. Samples must be analyzed as soon as practical after sampling, not to exceed 48 hours.5.pH: All methods allowed in 179 NAC 3-005.11A for measuring pH.6. Magnesium. All methods allowed in 179 NAC 3-005.11A for measuring magnesium.179 Neb. Admin. Code, ch. 16, § 004