Streamline - Summer 2015 - (Page 7)
BY PAM BAUGHMAN, VRWA PRESIDENT
A Disinfection Byproducts Odyssey
Environmental Protection Agency (EPA) adopted the Stage 1 Disinfectants and
Disinfection Byproducts Rule (DBP). The purpose of the Stage 1 Rule was to strengthen control of
chemical disinfectants like chlorine (the known disinfectant for over 100 years) and the potentially
cancer-causing byproducts in drinking water.
IN 1998 THE
The Stage 1
DBP Rules sets
limits on two
chlorine is added
to surface water
with high levels
of Total Organic
Carbon (TOC) and
The Stage 1 DBP Rules sets limits on two contaminants in drinking water created when chlorine is added
to surface water with high levels of Total Organic
Carbon (TOC) and Dissolved Organic Carbon (DOC).
Total Trihalomethanes (TTHM) and Haloacetic Acids
(HAA5) form in chlorinated (a disinfectant) water as
a result of the reaction that occurs when chlorine is
added to water with high organic materials (decaying
leaves, branches, grasses, trees etc.).
The Stage 2 DBP Rules came into effect during the
third quarter of 2014, further tightening the limits set by
the Stage 1 DBP Rules, by implementing site specific
compliance as opposed to a running annual average.
Louisa County Water Authority (LCWA) remained
in compliance, for the most part, with Stage 1 DBP
Rules; however, when the stage 2 DBP Rules came into
effect, the LCWA found it difficult to impossible to
meet the regulation without some combination of water
age reduction and Dissolved Organic Carbon removal.
What did we do?
In late 1999, the LCWA and the County of Louisa
(County) negotiated Addendum 3 to the Buy-Sell
Agreement with the Town of Louisa (Town). In that
agreement, the Town agreed to allow a lease for 15
years at no cost to LCWA for the use of the wells and
springs owned by Town. The cost to upgrade, maintain
and operate the wells and springs would be the responsibility of LCWA and the County. LCWA intended to
use the wells and springs as a supplemental source to
blend with the Northeast Creek Water Treatment Plant
(NECWTP) water. However, during our evaluation
in 2010 of the wells, it was determined that the wells
were contaminated with Tetrachloroethylene and also
influenced by surface water; rendering them unsuitable for human consumption.
In 2004, the first of two outside engineering
reviews was conducted. This evaluation consisted
of review of the current processes at the plant and
distribution system. The evaluation consisted of historical data and treatability studies (jar testing).
In 2009, LCWA contracted for an engineering report to evaluate DBP Reduction and the
development of control strategies.
Initially process changes were implemented at
the NECWTP including enhanced coagulation
(the reduction of pH in the treatment process). 6.2
Standard Units pH was indicated as the desirable
level. Higher doses of Alum were also fed. Finally,
the chlorine feed was relocated from pretreatment
to applied treatment to reduce the contact time
between the TOC and the chlorine.
Simulated Distribution System testing (SDS) was
conducted on the use of an alternative disinfectant
called chloramines. The SDS testing with the use
of chloramines did show a decrease in DBPs, but
not significantly enough to ensure compliance. The
Virginia Department of Health (VDH) determined
that due to the operational schedule (start-up and
shut-down daily) at the NECWTP, Chloramines
would not be a viable option. Chloramines also
produce DBPs that are currently unregulated, but
will be within the next seven years; those DBPs are
known in the utility business as "super bugs" and
chloramines can cause corrosion in the distribution
system, leading to lead and copper issues.
Table of Contents for the Digital Edition of Streamline - Summer 2015
From the President: A Disinfection Byproducts Odyssey
From the Executive Director: It’s Over
Importance of Professional Relationships in the Water and Wastewater Industry
Spring Cleaning … All Year Long
Region Meetings: the Next Big Thing
Preventing Heat-Related Illnesses
Virginia Source Water
USDA Rural Development
A Successful Model for Waterworks
Professional Licensing Update: News You Can Use
Tank Team Tackles Water Distribution
VRWA 2015 Conference Highlights
Town of Lovettsville Wins the ‘Great Water Taste Contest’
Throwing My Loop: Helpers in Our Path
VRWA Booster Club
Do You Know What Your VRWA Benefits Are?
Board of Directors
Index to Advertisers/Ad.com
Streamline - Summer 2015