Nebraska Administrative Code › Topic - HEALTH AND HUMAN SERVICES SYSTEM › Title 179 - PUBLIC WATER SYSTEMS › Chapter 16 - DISINFECTANTS AND DISINFECTION BYPRODUCTS › Section 179-16-002 - DEFINITIONS

Current through June 17, 2024
Code of Federal Regulations (CFR)
means the Code of Federal Regulations as it existed on the effective date of
				  these regulations, and any CFR citations mentioned in these regulations are
				  hereby incorporated by reference. Copies of the CFR as it existed on the
				  effective date of these regulations can be obtained on the DHHS website at
http://dhhs.ne.gov/publichealth/Pages/enh_pwsindex.aspx
or by requesting via email a copy from the Department at
DHHS.drinkingwater@nebraska.gov
or by calling
				  402-471-2541.
Enhanced coagulation
means the
				  addition of sufficient coagulant for improved removal of disinfection byproduct
				  precursors by conventional filtration treatment.
Enhanced softening
means the
				  improved removal of disinfection byproduct precursors by precipitative
				  softening.
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.
Haloacetic acids (five) (HAA5)
means the sum of the concentrations in milligrams per liter of the haloacetic
				  acid compounds (monochloroacetic acid, dichloroacetic acid, trichloroacetic
				  acid, monobromoacetic acid, and dibromoacetic acid), rounded to two significant
				  figures after addition.
Maximum residual disinfectant level
				  (MRDL)
means a level of a disinfectant added for water treatment
				  that may not be exceeded at the consumer's tap without an unacceptable
				  possibility of adverse health effects. For chlorine and chloramines, a public
				  water system (PWS) is in compliance with the MRDL when the running annual
				  average of monthly averages of samples taken in the distribution system,
				  computed quarterly, is less than or equal to the MRDL. For chlorine dioxide, a
				  PWS is in compliance with the MRDL when daily samples are taken at the entrance
				  to the distribution system and no two consecutive daily samples exceed the
				  MRDL. MRDLs are enforceable in the same manner as maximum contaminant levels.
				  There is convincing evidence that addition of a disinfectant is necessary for
				  control of waterborne microbial contaminants. Notwithstanding the MRDLs listed
				  in 179 NAC
				  2-002.04F1,
				  operators may increase residual disinfectant levels of chlorine or chloramines
				  (but not chlorine dioxide) in the distribution system to a level and for a time
				  necessary to protect public health to address specific microbiological
				  contamination problems caused by circumstances such as distribution line
				  breaks, storm runoff events, source water contamination, or
				  cross-connections.
Maximum residual disinfectant level goal
				  (MRDLG)
means the maximum level of a disinfectant added for water
				  treatment at which no known or anticipated adverse effect on the health of
				  persons would occur, and which allows an adequate margin of safety. MRDLGs are
				  nonenforceable health goals and do not reflect the benefit of the addition of
				  the chemical for control of waterborne microbial contaminants.
SUVA
means Specific Ultraviolet
				  Absorption at 254 nanometers (nm), an indicator of the humic content of water.
				  It is a calculated parameter obtained by dividing a sample's ultraviolet
				  absorption at a wavelength of 254 nm (UV254) (in
				  m-1) by its concentration of dissolved organic
				  carbon (DOC) (in mg/L).
Total organic carbon (TOC)
means
				  total organic carbon in mg/L measured using heat, oxygen, ultraviolet
				  irradiation, chemical oxidants, or combinations of these oxidants that convert
				  organic carbon to carbon dioxide, rounded to two significant
				  figures.