|
||||||
|---|---|---|---|---|---|---|
| Home | 29 CFR | 40 CFR | 49 CFR | Federal Register | MSDS Search | Purchase CFR e-Books |
§141.131 Analytical requirements.
(a) General. (1) Systems must use only the analytical method(s) specified in this section, or otherwise approved by EPA for monitoring under this subpart, to demonstrate compliance with the requirements of this subpart. These methods are effective for compliance monitoring February 16, 1999.
(2) The following documents are incorporated by reference. The Director of
the Federal Register approves this incorporation by reference in accordance with
5 U.S.C. 552(a) and 1 CFR part 51. Copies may be inspected at EPA's Drinking
Water Docket, 401 M St., SW., Washington, DC 20460, or at the Office of the
Federal Register, 800 North Capitol Street, NW, Suite 700, Washington DC. EPA
Method 552.1 is in Methods for the Determination of Organic Compounds in
Drinking Water-Supplement II, USEPA, August 1992, EPA/600/R-92/129
(available through National Information Technical Service (NTIS), PB92-207703).
EPA Methods 502.2, 524.2, 551.1, and 552.2 are in Methods for the
Determination of Organic Compounds in Drinking Water-Supplement III, USEPA,
August 1995, EPA/600/R-95/131. (available through NTIS, PB95-261616). EPA Method
300.0 is in Methods for the Determination of Inorganic Substances in
Environmental Samples, USEPA, August 1993, EPA/600/R-93/100. (available
through NTIS, PB94-121811). EPA Method 300.1 is titled USEPA Method 300.1,
Determination of Inorganic Anions in Drinking Water by Ion Chromatography,
Revision 1.0, USEPA, 1997, EPA/600/R-98/118 (available through NTIS,
PB98-169196); also available from: Chemical Exposure Research Branch,
Microbiological & Chemical Exposure Assessment Research Division, National
Exposure Research Laboratory, U.S. Environmental Protection Agency, Cincinnati,
OH 45268, Fax Number: 513-569-7757, Phone number: 513-569-7586. Standard Methods
4500-Cl D, 4500-Cl E, 4500-Cl F, 4500-Cl G, 4500-Cl H, 4500-Cl I, 4500-ClO (b) Disinfection byproducts. (1) Systems must measure disinfection
byproducts by the methods (as modified by the footnotes) listed in the following
table: (2) Analysis under this section for disinfection byproducts must be conducted
by laboratories that have received certification by EPA or the State, except as
specified under paragraph (b)(3) of this section. To receive certification to
conduct analyses for the contaminants in §141.64(a), the laboratory must carry
out annual analyses of performance evaluation (PE) samples approved by EPA or
the State. In these analyses of PE samples, the laboratory must achieve
quantitative results within the acceptance limit on a minimum of 80% of the
analytes included in each PE sample. The acceptance limit is defined as the 95%
confidence interval calculated around the mean of the PE study data between a
maximum and minimum acceptance limit of +/−50% and +/−15% of the study mean.
(3) A party approved by EPA or the State must measure daily chlorite samples
at the entrance to the distribution system.
(c) Disinfectant residuals. (1) Systems must measure residual
disinfectant concentrations for free chlorine, combined chlorine (chloramines),
and chlorine dioxide by the methods listed in the following table: (2) If approved by the State, systems may also measure residual disinfectant
concentrations for chlorine, chloramines, and chlorine dioxide by using DPD
colorimetric test kits.
(3) A party approved by EPA or the State must measure residual disinfectant
concentration.
(d) Additional analytical methods. Systems required to analyze
parameters not included in paragraphs (b) and (c) of this section must use the
following methods. A party approved by EPA or the State must measure these
parameters.
(1) Alkalinity. All methods allowed in §141.89(a) for measuring
alkalinity.
(2) Bromide. EPA Method 300.0 or EPA Method 300.1.
(3) Total Organic Carbon (TOC). Standard Method 5310 B
(High-Temperature Combustion Method) or Standard Method 5310 C
(Persulfate-Ultraviolet or Heated-Persulfate Oxidation Method) or Standard
Method 5310 D (Wet-Oxidation Method). TOC samples may not be filtered prior to
analysis. TOC samples must either be analyzed or must be acidified to achieve pH
less than 2.0 by minimal addition of phosphoric or sulfuric acid as soon as
practical after sampling, not to exceed 24 hours. Acidified TOC samples must be
analyzed within 28 days.
(4) Specific Ultraviolet Absorbance (SUVA). SUVA is equal to the UV
absorption at 254nm (UV (i) Dissolved Organic Carbon (DOC). Standard Method 5310 B (High-Temperature
Combustion Method) or Standard Method 5310 C (Persulfate-Ultraviolet or
Heated-Persulfate Oxidation Method) or Standard Method 5310 D (Wet-Oxidation
Method). Prior to analysis, DOC samples must be filtered through a 0.45 μm
pore-diameter filter. 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. DOC samples must be filtered
through the 0.45 μm pore-diameter filter prior to acidification. DOC samples
must either be analyzed or must be acidified to achieve pH less than 2.0 by
minimal addition of phosphoric or sulfuric acid as soon as practical after
sampling, not to exceed 48 hours. Acidified DOC samples must be analyzed within
28 days.
(ii) Ultraviolet Absorption at 254 nm (UV (5) pH. All methods allowed in §141.23(k)(1) for measuring pH.
[63 FR 69466, Dec. 16, 1998, as amended at 66 FR 3776, Jan. 16,
2001]
Approved Methods for Disinfection Byproduct Compliance Monitoring
--------------------------------------------------------------------------------------------------------------------------------------------------------
Byproduct measured \1\
Methodology \2\ EPA method Standard method -------------------------------------------------------
TTHM HAA5 Chlorite \4\ Bromate
--------------------------------------------------------------------------------------------------------------------------------------------------------
P&T/GC/ElCD & PID................. \3\502.2 ....................................... X ............ ............ ............
P&T/GC/MS............................. 524.2 ....................................... X ............ ............ ............
LLE/GC/ECD................................ 551.1 ....................................... X ............ ............ ............
LLE/GC/ECD................................ ........... 6251 B ............ X ............ ............
SPE/GC/ECD................................ 552.1 ....................................... ............ X ............ ............
LLE/GC/ECD................................ 552.2 ....................................... ............ X ............ ............
Amperometric Titration.................... ........... 4500-ClO[INF]2[/INF] E ............ ............ X ............
IC........................................ 300.0 ....................................... ............ ............ X ............
IC........................................ 300.1 ....................................... ............ ............ X X
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ X indicates method is approved for measuring specified disinfection byproduct.
\2\ P&T = purge and trap; GC = gas chromatography; ElCD = electrolytic conductivity detector; PID = photoionization detector; MS = mass
spectrometer; LLE = liquid/liquid extraction; ECD = electron capture detector; SPE = solid phase extractor; IC = ion chromatography.
\3\ If TTHMs are the only analytes being measured in the sample, then a PID is not required.
\4\ Amperometric titration may be used for routine daily monitoring of chlorite at the entrance to the distribution system, as prescribed in §
141.132(b)(2)(i)(A). Ion chromatography must be used for routine monthly monitoring of chlorite and additional monitoring of chlorite in the
distribution system, as prescribed in § 141.132(b)(2)(i)(B) and (b)(2)(ii).
Approved Methods for Disinfectant Residual Compliance Monitoring
--------------------------------------------------------------------------------------------------------------------------------------------------------
Residual Measured \1\
-------------------------------------------------------
Methodology Standard method ASTM method Free Combined Total Chlorine
chlorine chlorine chlorine dioxide
--------------------------------------------------------------------------------------------------------------------------------------------------------
Amperometric Titration.............. 4500-Cl D D 1253-86 X X X ............
Low Level Amperometric Titration.... 4500-Cl E ............................ ............ ............ X ............
DPD Ferrous Titrimetric............. 4500-Cl F ............................ X X X ............
DPD Colorimetric.................... 4500-Cl G ............................ X X X ............
Syringaldazin e (FACTS)............. 4500-Cl H ............................ X ............ ............ ............
Iodometric Electrode................ 4500-Cl I ............................ ............ ............ X ............
DPD................................. 4500-ClO[INF]2[/INF] D ............................ ............ ............ ............ X
Amperometric Method II.............. 4500-ClO[INF]2[/INF] E ............................ ............ ............ ............ X
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ X indicates method is approved for measuring specified disinfectant residual.
