City Manager's Bi-Weekly Report Volume 2 | Issue 14 | September 14, 2018 | Page 16
Utility Systems Cont’d
Why Free Chlorinate?
Free chlorination of our vast water distribution system is
currently underway. We are temporarily modifying the
disinfection process between August 31 and September 28.
Port St. Lucie Utility Systems has not conducted a free
chlorination operation since May 2008, which is a testament
to our ability to maintain our outstanding water quality.
Martin County Utilities, West Palm Beach Public Utilities,
City of Fort Lauderdale, and Miami-Dade Water Department
are just a few of our many neighboring utilities who conduct
free chlorination annually or as they deem necessary.
The Florida Department of Environmental Protection (FDEP)
cites in their Disinfection Byproducts Requirements the
following, "The definition of 'normal operating conditions'
include any routine maintenance practices. An event such as
a chlorine burn, a switch from chloramine to chlorine, is
considered to be part of normal operations of a system for
periodic maintenance. A water line break or other disruptive
event which is outside the control of the facility is
considered non-normal operation condition. The length of
chlorine burns should be kept to a maximum of 21 days.
Whenever possible, systems should try to optimize
processes using guidance such as AWWA manual 'A Guide to
the Implementation and Use of Chloramines'."
The American Water Works Association (AWWA) states,
“chloramines are widely used to maintain a disinfectant
residual in water distribution systems. However,
chloraminated distribution systems can promote the growth
of nitrifying bacteria, an undesirable condition known as
nitrification. Many chloraminated systems minimize the
potential for nitrification by converting from chloramines to
free chlorine on a periodic basis. The concept behind this
switch is that free chlorine will oxidize any ammonia present
in the distribution system, thus removing the food source for
nitrifying bacteria, and will reduce the number of nitrifying
bacteria.”
Our Promise
Port St. Lucie Utility Systems will continue to work closely
with FDEP and our other regulatory agencies to maintain
and provide a safe and clean water supply for our customers
through the use of preventative maintenance and industry-
wide best practices. Water is essential for life and it is
essential for this utility to continue to provide clean, safe,
great-tasting drinking water our customers can trust.
References:
1. Florida Department of Environmental Protection
Memorandum: Clarification of Rile 62-550.822 Disinfection
Byproducts (DBP) Requirements
2. American Chemistry Council
https://chlorine.americanchemistry.com/Chlorine/
DrinkingWaterFAQ/
2. American Water Works Association
https://www.awwa.org/store/productdetail.aspx?
productid=7989
3. Centers for Disease Control and Prevention
https://www.cdc.gov/healthywater/drinking/public/chlorine
-disinfection.html
4. Port St. Lucie Utility Systems 2017 Water Quality Report
Hydrant flushing schedule
Watch Positively Port St. Lucie for an in-depth
discussion with Utility Systems Laboratory, Cross
Connection, and Environmental Compliance Manager Joe
Presti and Cross Connections Supervisor Glen Cockrell.
16