A Comparative Study of On-line and Laboratory TOC Analyzers for Analysis of Raw and Finished Drinking Water0 pages

Application Note 39450413

Keywords
Aurora 1030W TOC Analyzer
Disinfectants / Disinfection
Byproducts Rule (D/DBPR)
9210p On-line TOC Analyzer
Fulvic Acid
Humic Acid
Natural Organic Matter (NOM)
U.S. EPA Method 415.3
Standard Method SM 5310C

A Comparative Study of On-line and Laboratory
TOC Analyzers for Analysis of Raw and Finished
Drinking Water

Introduction
Total organic carbon (TOC) analysis is an important indicator of water
quality throughout the drinking water treatment process. Raw source
water is progressively treated in chemical coagulation, flocculation,
sedimentation, and filtration steps to remove particulate matter and
natural organic matter (NOM). Humic acid and fulvic acids contained in
the residual NOM of water undergoing disinfection by chlorination react
with chlorine to form disinfection by-product compounds such as
trihalomethanes (THMs) and haloacetic acids (HAAs), which have been
linked to cancer. THMs continue to form during drinking water
distribution due to excess chlorine levels required to maintain microbial
disinfection.
Disinfectants and Disinfection Byproducts Rule

The U.S. EPA has issued two rules regulating levels of disinfectants and
disinfection by-products in drinking water. The Stage 1 Disinfectants and
Disinfection Byproducts Rule (D/DBPR) was promulgated in 1998(1) and
took effect on January 1, 2002. This rule lowered permissible levels of
trihalomethanes (THMS) to 80 μg/L and regulated levels for five
haloacetic acids (HAAs), bromate and chlorite in drinking water for the
first time.(2)
The USEPA Stage 2 D/DBPR was promulgated in 2006.(3) Compliance
dates for the Stage 2 D/DBPR are phased in over time based upon the
number of people served by a water system. The compliance date for
systems serving over 100,000 people was April 1, 2012. Systems serving
10,000-49,000 people and less than 10,000 people must be in compliance
by October 1, 2013.(4) TOC analysis is an indicator of NOM and THM
levels in source water and finished drinking water.(5)
Drinking Water Security

Presented at the 2013 Pittsburgh
Conference on Analytical
Chemistry and Applied
Spectroscopy, Philadelphia,
Pennsylvania, March 17-21, 2013

The U.S. Government has passed legislation and issued directives to
protect the nations’ water supply infrastructure(6). Title IV of the Public
Health Security and Bioterrorism Preparedness and Response Act
requires drinking water systems serving more than 3,300 people to
develop response measures to incidents that could disrupt the supply of
safe drinking water, or pose serious public health concerns(7). Under
Homeland Security Presidential Directive 9 the USEPA is responsible for
developing a “robust, comprehensive surveillance and monitoring
program to provide early warning in the even of a terrorist attack using
biological, chemical, or radiological contaminants”(8).
On-line TOC monitoring of drinking water supply systems provides
warning of organic chemical contamination from accidental or intentional