Section 179-13-004 - CRITERIA FOR AVOIDING FILTRATIONA public water system that uses a ground water source under the direct influence of surface water must meet all of the conditions of 179 NAC 13-004.01 and 13-004.02 and is subject to 179 NAC 13-004.03 beginning 18 months after the Director determines that it is under the direct influence of surface water. Within 18 months of the failure of a system using a ground water source under the direct influence of surface water to meet any one of the requirements of 179 NAC 13-004.01 to 13-004.06 the system owner must have installed filtration and meet the criteria for filtered systems specified in 179 NAC 13-006.
004.01 Source Water Quality Conditions 13-004.01A The fecal coliform concentration must be equal to or less than 20 per 100 ml or the total coliform concentration must be equal to or less than 100 per 100 ml (measured by the Department Laboratory or an approved laboratory pursuant to 179 NAC 3-009) in representative samples of the source water immediately prior to the first or only point of disinfection application in at least 90% of the measurements made for the six previous months that the system served water to the public on an ongoing basis. If a system measures both fecal and total coliforms, the fecal coliform criterion, but not the total coliform criterion, in this paragraph must be met.13-004.01B The turbidity level cannot exceed 5 NTU (measured as specified in 179 NAC 13-007.01A and 13-007.02B) in representative samples of the source water immediately prior to the first or only point of disinfectant application unless: 1. The Director determines that any such event was caused by circumstances that were unusual and unpredictable; and2. As a result of any such event, there have not been more than two events in the past 12 months the system served water to the public, or more than five events in the past 120 months the system served water to the public, in which the turbidity level exceeded 5 NTU. An "event" is a series of consecutive days during which at least one turbidity measurement each day exceeds 5 NTU.004.02 Site-Specific Conditions 13-004.02A The public water system must meet the requirements of 179 NAC 13-005.01A at least 11 of the 12 previous months that the system served water to the public on an ongoing basis, unless the system fails to meet the requirements during 2 of the 12 previous months that the system served water to the public and the Director determines that at least one of these failures was caused by circumstances that were unusual and unpredictable.13-004.02B The public water system must meet the requirements of 179 NAC 13-005.01B at all times the system serves water to the public.13-004.02C The public water system must meet the requirements of 179 NAC 13-005.01C at all times the system serves water to the public unless the Director determines that any such failure was caused by circumstances that were unusual and unpredictable.13-004.02D The public water system must meet the requirements of 179 NAC 13-005.01D on an ongoing basis unless the Director determines that failure to meet these requirements was not caused by a deficiency in treatment of the source water.13-004.02E The public water system owner must develop and implement a wellhead protection program sufficient to exclude potential sources of microbiological contamination within a one year time-of-travel from the well or well field. A wellhead protection program must consist of the following: 1.A Wellhead Protection Area Delineation: The area delineated must be based on a one year time-of-travel and must be determined by use of a computer model acceptable to the Department or by the following formula: T = 3.14nbL2 divided by Q
Where T = Time-of-Travel (days)
L = Distance from the well (feet)
n = Effective porosity (assumed to be 0.2 unless supporting evidence indicates otherwise) b = Aquifer thickness (feet)
Q = Pumping rate (cubic feet per day)
2. Identification of all sources of microbiological contamination within the delineated area.3. Management of all sources identified in 179 NAC 13-004.02E item 2 to prevent contamination from the sources.004.03 The public water system must be subject to an annual on-site inspection to assess the wellhead protection program specified in 179 NAC 13-004.02E and the disinfection treatment process. Either the Director or a party approved by the Director must conduct the on-site inspection. The inspection must be conducted by competent individuals such as sanitary and civil engineers, sanitarians, or technicians who have experience and knowledge about the operation and maintenance of a public water system, and who have a sound understanding of public health principles and waterborne diseases. A report of the on-site inspection must be prepared every year and indicate to the Director's satisfaction that the disinfection treatment process is adequately designed and maintained. The on-site inspection must include: 1. A review of the effectiveness of the wellhead protection program required by 179 NAC 13-004.02E;2. A review of the physical condition of the well and the extent of protection provided;3. A review of the system's equipment maintenance program to ensure there is low probability for failure of the disinfection process;4. An inspection of the disinfection equipment for physical deterioration;5. A review of operating procedures;6. A review of data records to ensure that all required tests are being conducted and recorded and disinfection is effectively practiced; and7. Identification of any improvements which are needed in the equipment, system maintenance and operation, or data collection.004.04 The public water system must not have been identified as a source of a waterborne disease outbreak, or if it has been so identified, the system must have been modified sufficiently to prevent another such occurrence, as determined by the Director.004.05 The public water system must comply with the maximum contaminant level (MCL), for total coliforms in 179 NAC 2-002.04C1 and 2-002.04C2 and the MCL for E. coli in 179 NAC 2-002.04C4 at least 11 months of the 12 previous months that the system served water to the public, on an ongoing basis, unless the Director determines that failure to meet this requirement was not caused by a deficiency in treatment of the source water.004.06 The public water system was required to comply with the requirements for trihalomethanes in 179 NAC 2-002.04B1 and 179 NAC 3-006 until December 31, 2001. After December 31, 2001, the system must comply with the requirements for total trihalomethanes, haloacetic acids (five), bromate, chlorite, chlorine, chloramines, and chlorine dioxide in 179 NAC 16.004.07 A system that fails to meet any one of the criteria in 179 NAC 13-004.01 and 13-004.02, and/or for which filtration is required, and fails to install filtration is in violation of a treatment technique requirement.004.08 A system that has not installed filtration is in violation of a treatment technique requirement if: 1. The turbidity level (measured as specified in 179 NAC 13-007.01A) in a representative sample of the source water immediately prior to the first or only point of disinfection application exceeds 5 NTU; or2. The system is identified as a source of a waterborne disease outbreak.179 Neb. Admin. Code, ch. 13, § 004
Amended effective 3/22/2016.