AL/MS AWWA
Effective Backflow
Prevention
August 26, 2013
Sam McElroy, PE
Civil Services, LLC
sammc@knology.net
(256) 755-0050
Introduction
•
•
•
•
•
Years ago, water systems did not include any form of backflow prevention in
system designs.
Today, systems are required by law to develop and implement a backflow
prevention program which meets state’s requirements.
We will look at basic policies for residential, commercial, irrigation and fireline
backflow prevention.
To help establish if the program is effective, we will consider the functionality,
cost, and convenience of the system.
We will also consider the acceptance of the program by the customers, the
public and regulatory officials.
Cross Connection/Backflow
Prevention - Definitions
•
•
•
•
•
•
•
Cross Connection - Any physical connection or other arrangement through
which unauthorized or potentially harmful materials can be introduced into
drinking water.
Backflow – a reversal of the normal direction of flow within a piping system.
A backflow program should effectively protect a water system’s distribution lines
from contamination or pollution from foreign substances which may compromise
health.
Check Valves -- typically do not have test ports. Are not considered true
backflow preventers.
Dual checks -- low hazard installations.
Double Checks -- standard installations. Most common required.
RPZ --- high hazard installations, chemicals, treatment plants, hospital.
Backflow Prevention - What is it?
Backflow Prevention - What is it?
Backflow Prevention Codes
• No single rule.
• Different states, city, counties have different
requirements.
• Authority having jurisdictions may vary – water
departments, fire departments, regulatory
agencies, health department, inspection
departments, etc.
Backflow Prevention
Alabama vs. Mississippi BFP
Requirements
• Alabama State Law
• alabamaBFP.pdf
• Every connection shall have a BFP installed.
Alabama vs. Mississippi BFP
Requirements
• mscrossconnection.pdf
• Mississippi State Law
• No low hazard installation shall be required to
have a BFP.
Cost
• Installation Cost
• Maintenance Cost
• Eye Soar - Above ground installations, loss of
land use
• Monitoring systems on some installations
Communication
• Does the public understand your BFP policy?
• How do you communicate your departmental
requirements.
• How does the industry communicate BFP
requirements?
• Marble Mountain Sprinkler Burn.mpg
Effective BFP Programs
• Many different programs and requirements exist for BFP
requirements.
• Each system is required by law to develop and implement a
backflow prevention program which meets minimum state’s
requirements.
• Your program is most effective when you consider the
functionality, cost, and convenience of the program.
• These aspects of the program should convey to customers
the value of life safety though effective communications with
customers and the public.
• Questions ???
• Comments …
Sam McElroy, PE
Civil Services, LLC
sammc@knology.net
(256) 755-0050