Report to: General Committee Date
of Meeting: May 9, 2007
Community Services and Environment
SUBJECT: Protection of the Water
Distribution System through Backflow Prevention and Cross-Connection Control
PREPARED BY: Robert Flindall, Manager,
Operations and Maintenance
RECOMMENDATION:
THAT Council endorse
the proposed strategy to implement a backflow prevention and cross-connection control
program for protection of the Markham
drinking-water system as set out in this report;
AND THAT Council enact
a By-law to regulate cross-connections and backflow prevention on private
plumbing systems in a form substantially similar to Attachment ‘B’;
AND THAT staff be
authorized and directed to review and bring forward for consideration
technologies that can reduce the risk and impact of contamination of the
drinking-water system due to backflows originating from those properties that
are currently exempted from the provisions of the By-law;
AND FURTHER THAT Staff
be authorized and directed to do all things necessary to give effect to this
resolution.
EXECUTIVE SUMMARY:
The Ministry of the
Environment (MOE) has recommended that the Town of Markham implement a By-law to prevent
backflows from non-potable water systems into the municipal drinking water
system and control cross–connections between potable and non-potable water
systems. A similar recommendation has
been received by all of the municipalities in York Region. At the meeting of May10, 2005 Council
directed staff to report back on an inter-departmental
strategy to implement the MOE recommendation to enact a By-law to protect the
municipal drinking-water system from backflows and back-siphonage. Staff has
developed a program and a draft By-law that will satisfy the requirements of
the MOE recommendations that will provide added protection and security for the
municipal water supply.
The
proposed By-law will apply to all property within the
Town, except buildings or structures of
residential occupancies where each dwelling unit is individually serviced from
the municipal drinking-water system through a single connection less than 50mm
diameter. The exempted properties are generally all
single family residential dwellings, while affected properties are generally
commercial or industrial establishments.
However, any residential properties with connections to both the municipal drinking-water system and another potable water system, certain types of fire protection
system, or a lawn sprinkler system would also be required to comply with the
By-law. Owners are not permitted to
connect private wells to plumbing systems that are connected to the municipal
drinking-water system.
The By-law
will require property owners to perform annual testing of all backflow
prevention devices and to submit the test performance results to the Town. The
By-law will also require property owners to conduct and submit a survey of the plumbing on his/her property every three (3) years to identify existing
cross-connections, and to identify the sufficiency of existing or required backflow
prevention devices. The By-law supports
the Building Code requirements for backflow prevention by requiring testing of existing
installed devices, however the By-law does not supersede the Building Code or impose
any higher standard for construction of new buildings and plumbing systems. The By-law is consistent with the By-laws
adopted in many other municipalities in the province.
FINANCIAL CONSIDERATIONS
AND TEMPLATE:
Implementation of the Cross-Connection Control By-law will require
on-going staffing and information technology resources to commensurate with
growth in the Town and evolving drinking water regulations.
Funds have
been allocated in the 2007 Waterworks
Capital Budget under the Capital expenditure account #53-6150-7683-005 for the
purchase or development of a records management and tracking systems to assist
in the administration of Waterworks compliance programs. The requirements for the records management and
tracking system will be assessed as part of the proposed implementation
strategy described in this report. When the requirements and specifications are
finalized the capital and operating needs will be adjusted as required.
Compliance of the
Town-owned properties with the requirements of the By-law will have a future
effect on the operating budgets of other departments. As a minimum, the Operations
Department, Asset Management Department and Recreation Department operating
budgets will have to provide for annual testing of backflow prevention
assemblies, and periodic cross-connection control surveys within municipal
properties. The anticipated cost to
conduct the cross-connection surveys and testing of backflow prevention devices
at 70 affected municipal properties is approximately $28,000 per year. The
testing of backflow prevention devices could identify inoperable devices or
other deficiencies that would require repairs or upgrades. The funding requirements for the on-going surveys,
annual testing and necessary repairs, if required, will be brought forward for
consideration by the affected Department in their 2008 Operating Budget.
The
Building Standards Department anticipates the potential requirement for one
Building Inspector II position in year 2009, or later, if implementation of the
By-law results in a large number of plumbing permits being issued to property
owners that are undertaking upgrades to their plumbing to correct deficiencies.
The requirement for this position will
be evaluated after the By-law is implemented and an assessment is made of the
number of additional plumbing permits being issued. This position, if required, will be brought forward
for consideration by the Building Standards Department in their 2009 Operating
Budget and will be funded through collection of Building Permit fees as set out
in By-law #2005-190.
PURPOSE:
The purpose of this
report is to recommend that Council adopt the proposed strategy to implement a
backflow prevention and cross-connection control program for protection of the Markham drinking-water
system.
BACKGROUND:
The Ministry of the
Environment (MOE) has inspected the Town of Markham water distribution system annually
since 2004 for compliance with Regulations made under the Safe Drinking Water Act, and with respect to Ministry policies and guidelines. On each occasion since 2004 the MOE has identified
that Markham
does not have a program or By-law to prohibit cross-connections between the
municipal drinking-water system and non-potable water sources. The MOE recommends as a “Best Management
Practice” that a backflow prevention and cross–connection control By-law be
enacted. A similar recommendation has
been received by all of the municipalities inspected by the MOE in York Region. At the meeting of May10, 2005 Council
directed staff to report back on an inter-departmental
strategy to implement the MOE recommendation to enact a By-law to control cross
connections between the municipal drinking-water system and non-potable water
sources.
The potential for
harmful effects resulting from a backflow incident caused by a cross-connection
has recently been highlighted by an event that occurred at a car wash in Stratford, Ontario
on March 7, 2005. On that day, a cleaning detergent from the
car-wash entered the municipal water supply during a backflow incident caused by
defective backflow prevention equipment.
The majority of the City was placed on an Unsafe Water Advisory by the
Medical Officer of Health until the chemical had been entirely flushed from the
system. The owner of the car wash was
subsequently charged with two counts under Section 20(1) (a) and 20(1) (c) of
the Safe Drinking Water Act, for
causing or permitting detergent to enter the city’s drinking water system which
resulted in a health hazard and resulted in the interference with the normal
operation of the drinking water system. The
owners were ordered by the MOE to immediately repair the backflow prevention
equipment.
The City of Stratford had enacted a
cross connection control By-law in March, 2004 but the implementation of this
By-law, including testing of backflow prevention devices had not been
implemented prior to the car wash incident.
OPTIONS/ DISCUSSION:
Private Plumbing Owner
Responsibilities and Municipal Responsibilities
Owners of private
plumbing systems have the responsibility to ensure that cross connections in
private plumbing are prevented or eliminated in order to protect the municipal
supply during back-siphonage or back pressure occurrence. This requirement is made clear in the Ontario
Building Code Act and Regulations.
The municipality also
has a “duty of care” that must be exercised with respect to the drinking water
supply. A water purveyor has an
obligation under the Safe Drinking Water
Act to protect its drinking water supply from contamination, and to supply
potable water to its customers. Section
11 of the Safe Drinking Water Act
requires every owner of a municipal drinking-water system ensure the following:
“That all water provided by the system to the
point where the system is connected to a user’s plumbing system meets the
requirements of the prescribed drinking-water quality standards.”
The experiences in Stratford and Walkerton
show that once the municipal system is contaminated, it can take days and weeks
to remove the pollutants and restore the potable water supply. The cost in terms of human health, monetary
value, and public confidence can be extremely high.
The Ministry of the
Environment has recently approved and finalized the Drinking Water Quality
Management Standard (DWQMS) for drinking-water systems required under the Safe Drinking Water Act. A key component of the DWQMS is the
requirement for the Operating Authority to undertake a risk assessment for the
drinking-water system, and then implement and document a process for managing
those risks. The tasks involved in
satisfying this element of DWQMS include identifying the potential hazards,
assessing the risks, and identifying the control measures to address the
hazards. For the Markham distribution system backflow and
back-siphonage of non-potable water is one of the main hazards that cannot be
otherwise controlled through treatment and the standard operating practices of
the Waterworks Department.
Currently the Town of Markham relies on Section
7.6.2 of the Ontario Building Code for prevention of backflow and cross-connections
within the plumbing of newly constructed buildings. The Building Code Act and Regulations are
enforced by the Markham Building Standards Department. The Building Code requires identification
and control of cross-connections and prevention of backflow during the design
of plumbing systems. The Building Code Regulation was updated in 2006 including
many revisions to the requirements for backflow prevention. The Building Code now includes a requirement for
premise isolation for buildings or facilities where a potentially severe health
hazard may be caused by backflow. This
means that commercial properties containing process that could cause a severe
health hazard will have a backflow prevention device installed where the
municipal supply enters the building or property.
The provisions of the
Building Code cannot completely protect the municipal drinking-water system
because backflow prevention devices are only tested at the time of
installation, but do not require any subsequent testing. The municipality has no mechanism under the
Building Code to verify that the cross-connection control measures and devices
continue to work as intended following initial installation. A municipal By-law is required to
continuously protect the municipal drinking-water system through a program of
periodic inspections in order to identify and eliminate cross-connections, and routine
testing of backflow prevention devices to ensure they continue to function
properly. Backflow prevention testers
report that the typical failure rates for backflow prevention devices installed
in commercial locations is approximately 25% annually. Waterworks has found that the failure rate is
approximately 75% annually for backflow preventers used with hydrant meters and
in other construction applications.
Another area of
concern that has been addressed by the proposed By-law is the protection of the
drinking-water system from cross-connections and backflow from plumbing systems
that may no longer conform to the Code
requirements due to unreported modifications, or because they were constructed
in the past under different Code requirements.
A By-law is required to ensure that these plumbing systems are routinely
surveyed by professionals familiar with the Building Code and backflow
prevention methods. These surveys will
identify cross-connections and inadequate protection against backflow and
provide property owners with the information required to correct these
situations.
The provisions of the
Building Code do not address the potential for back-siphonage from fire service
mains constructed to supply water to private fire hydrants. While these hydrants are necessary for fire
protection, the water in the fire service mains rapidly loses its chlorine
residual and the water becomes non-potable as it sits unused in the pipes. This is a concern because this stagnant water
is easily drawn back into the municipal supply. Private fire hydrants are also
a location where uncontrolled access to the municipal water supply can occur
and therefore represent a potential contamination source. A method of ensuring that private fire
service mains and fire hydrants are routinely flushed is required.
The municipal
drinking-water system is also vulnerable to incidents of malicious, negligent,
or accidental backflow and back-siphonage. The majority of connections to the
drinking-water system are from residential properties, of which there are more
than 65,000 in the Town. The Town should
continue to explore various technologies and practices to identify backflow and
back-siphonage events as they are occurring, and develop procedures to provide
rapid response to contamination of the system.
Markham Backflow Prevention and
Cross-Connection ELIMINATION Strategy
The
proposed strategy to eliminate cross-connections and prevent backflow of
non-potable water into the municipal drinking-water system is as follows:
·
Adoption
of a municipal By-law to prevent cross-connections in plumbing and to ensure
that property owners maintain backflow prevention devices in working
condition. A draft By-law for consideration
is provided as Attachment ‘B’. A brief
description of the By-law and its application is provided in the following
section.
·
Development
and implementation of a public education program to ensure the public is aware
of the need for the By-law and the requirements of the By-law, including
compliance deadlines
·
The
Waterworks System Engineering Section will be responsible for administration of the By-law;
developing a public education program with respect to backflow prevention and
cross-connection control; and assisting property owners with compliance
issues. Building Code compliance will
continue to be administered and enforced through by the Building Standards
Department.
·
Development
of a Cross-Connection Control By-law tracking and compliance database
system. This system would provide a
database of all properties included in the program and would provide a
repository for backflow preventer test and cross-connection survey data. The property database system would also
provide notification of compliance issues and system performance issues to Waterworks, Building Standards, Fire Department, and
By-law. Waterworks
is evaluating use of the Town’s existing AMANDA, HANSEN and GIS information systems
for this purpose along with other software.
The estimated cost for this
project has been approved as a project in the 2007 Waterworks
Capital Expenditure Budget.
·
Explore
various technologies and practices to protect the water distribution system
from negligent or accidental backflow and back-siphonage. These technologies include the use of automatic meter readers that can
detect reverse flow through the water meter, and district management area
monitors that can detect fluctuations in system pressures and flows that would
indicate a back-siphonage event. These
systems report can back through a SCADA (Supervisory Control and Data
Acquisition) to a centralized location for continuous monitoring of the
distribution system.
Proposed By-law Application and Requirements
The main features of the proposed By-law are described
as follows:
Application of the
By-Law
The
proposed By-law will apply to all property within the
Town, except buildings or structures of
residential occupancies where each dwelling unit is individually serviced from
the municipal drinking-water system through a single connection less than 50mm
diameter. These properties are generally all single family
residential dwellings. However, any
residential properties with connections to both the municipal drinking-water system and any other potable water system, certain types of fire protection
system, or a lawn sprinkler system would also be required to comply with the
By-law. There are approximately 2,500
industrial, commercial, and institutional properties within the Town that would
be affected by this By-law, including approximately 70 municipally owned
buildings.
There are no fees
collected by the Town or permits issued by the Town. Compliance is based on the
submission of acceptable test results for backflow prevention devices, and
submission of completed and acceptable cross-connection surveys of the plumbing
system.
Owner’s
Responsibility to Eliminate Cross-Connections
The
proposed By-Law requires the private owner to identify and eliminate any cross-connections
in plumbing and fire service mains which could allow backflow of contaminants
into the municipal drinking water system. This responsibility is consistent
with the provisions of Section
7.6.2.of the Building Code Regulation, and with Sections 20(1) (a) and 20(1)
(c) of the Safe Drinking Water Act
which prohibit a person from causing or permitting any thing to enter a
drinking water system which could result in a drinking water hazard or
interfere with the normal operation of a drinking-water system.
Owner’s
Responsibility to Conduct a Cross-Connection Survey
The proposed By-law
will require every owner of an applicable property to conduct a survey, by
authorized personnel, of the plumbing on his/her
property every three (3) years to identify any potential cross-connections, and
to identify the sufficiency of existing or required backflow prevention
devices. This report must be submitted to the Town in order to update the
Town’s tracking system and to verify that modifications have not been made to
the plumbing system that could result in a new unprotected
cross-connection. The frequency of these
surveys is consistent with the By-laws of other municipalities. The Building Department has indicated that
the “Best Practice” would be annual inspections.
Owner’s
Responsibility to Test Backflow Prevention Devices and Assemblies
The proposed By-law will ensure that private owners annually
test and maintain the backflow prevention devices in
their plumbing system. Certain devices require
annual testing in accordance with the CSA
Standard, CAN/CSA-B64.10.1-01
Manual for the Selection and Installation
of Backflow Prevention Devices. The frequency of testing proposed in the
By-law is consistent with the By-laws of other municipalities and is as per the
requirements of the CSA Standard.
Owner’s Responsibility to Maintain Fire
Service Main
The proposed By-law requires the owner to inspect
all fire hydrants annually as required by the Ontario Fire Code and to submit to the Town a copy of the hydrant
inspection. The annual hydrant inspection described in the Ontario Fire Code includes a requirement fully
open the main valve of the hydrant and flow the hydrant through one hose
connection port in order to check the flows.
This is normally sufficient to flush stagnant
water from fire service mains.
Submission of the hydrant inspection record has an added benefit to the Town
and private owners by ensuring that all private fire hydrants are inspected and
maintained in operating condition. The
inspection information collected will be shared with the Fire Department.
Date of Compliance
Completion
of the first cross-connection survey and testing of backflow prevention devices
and assemblies shall occur prior to the date set out below for the degree of
hazard. A guide to the assessment of
hazards from various types of cross-connection is provided in CSA Standard
CAN/CSA-B64.10-01 Manual for the Selection and Installation of Backflow
Prevention Devices.
|
Degree of Hazard According
To CAN/CSA-B64.10-01
|
Compliance Date
|
|
Severe
|
(one year from By-law adoption)
|
|
Moderate
and Minor
|
(three
years from By-law adoption)
|