Louisiana Administrative Code › Title 51 - PUBLIC HEALTH-SANITARY CODE › Part XII - Water Supplies › Chapter 13 - Disinfectants and Disinfection Byproducts Rule › Subchapter B - Disinfection Byproduct (DBP) Precursor Control › Section XII-1305 - Monthly TOC Monitoring/Reporting

Current through Register Vol. 50, No. 6, June 20, 2024
A. Public water systems, meeting §1303. A applicability requirements of this Subchapter, shall submit the results of
				  their paired (source water and treated water) total organic carbon (TOC)
				  samples (which have been collected for compliance determination in accord with
				  the system's approved D/DBPR monitoring plan) to the state health officer
				  monthly for each individual treatment plant. In addition, the result of source
				  water alkalinity sampling conducted at the same time as the source water TOC
				  sample shall also be submitted to the state health officer monthly for each
				  individual treatment plant. The actual monthly TOC percent removal and the
				  removal ratio (reported to two significant figures past the decimal point)
				  shall be calculated in accord with
				  40
				  CFR 141.135(c) and indicated
				  on the form. All results for each particular plant shall be on a report form
				  approved by the state health officer. Such report shall specifically be
				  provided to the OPH District Engineering office which has jurisdictional
				  oversight of the public water system within 10 days following the end of each
				  calendar month.
B. When monthly TOC
				  percent removal calculations performed under Subsection A of this Section
				  result in a negative number (indicative of having a higher level of TOC in
				  treated water than in source water), a "0" percent removal shall be reported
				  for that particular paired sample set instead of the negative number. If this
				  should happen, OPH recommends that an additional paired sample set of TOC
				  samples be collected later in that same month. If the system chooses to collect
				  an additional paired sample set of TOC samples during that same month, the
				  system shall mathematically average the "0" result of the first paired sample
				  set with the result of the second paired sample set and report such average as
				  the monthly TOC percent removal achieved on the monthly TOC report form. If the
				  system does not choose to collect an additional paired sample set of TOC
				  samples during that same month, the system shall report a "0" percent removal
				  achieved on the monthly TOC report form.
C. Plant sites having multiple treatment
				  trains shall perform TOC paired monitoring on each treatment train and report
				  the results of each separate treatment train on its own, individual, and
				  properly identified TOC monthly operating report. The actual monthly TOC
				  percent removal and the removal ratio (reported to two significant figures past
				  the decimal point) for the entire plant site shall be determined by performing
				  a flow-weighted average using the results from each individual treatment train.
				  Flow-weighted averaging shall be based upon the flows at the moment in time
				  that the samples are collected. The percent flow attributed to each treatment
				  train shall be reported and shown in the flow-weighted average calculation
				  formula.
1. On a case-by-case basis, a system
				  may apply to DHH-OPH for approval of the use of a flow-weighted sample
				  composite of all treatment trains in lieu of individual TOC analyses of each
				  individual treatment train. The flow-weighted sample shall be composited by
				  laboratory personnel using aliquots from individual samples collected from each
				  treatment train. Flow-weighted averaging shall be based upon the flows at the
				  moment in time that the samples are collected. Each sample composite shall
				  consist of aliquots from no more than five different treatment trains. Each
				  laboratory report of a sample composite shall identify the specific treatment
				  trains associated with the composited sample.
2. On a case-by-case basis, a system may
				  apply to DHH-OPH for a waiver allowing monitoring of only one treatment train
				  at a facility having multiple treatment trains if the system can demonstrate
				  consistency in TOC sample results between each of the different treatment
				  trains located at the facility. If such waiver is granted, it shall be
				  stipulated therein that the waiver shall automatically cease if any treatment
				  changes are made which may affect the continued consistency between TOC sample
				  results between the various treatment trains.