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NEW WATERMAIN COMMISSIONING REQUIREMENTS

TABLE OF CONTENTS

Definitions: .................................................................................................................................................... 3

1.0 INTRODUCTION ................................................................................................................................. 4

1.1 Obligations .................................................................................................................................... 4

1.2 Requests ........................................................................................................................................ 4

1.3 Mandatory Submissions ................................................................................................................ 4

1.4 Site Meetings ................................................................................................................................ 5

2.0 NEW WATERMAIN – PHYSICALLY SEPARATED FROM EXISTING WATERMAIN ................................. 5

2.1 Installation and Certification of Backflow Prevention Device ...................................................... 5

2.2 Loading and Swabbing .................................................................................................................. 6

2.3 Flushing for Turbidity and Turbidity Testing ................................................................................. 6

2.4 Hydrostatic Pressure Testing ........................................................................................................ 6

2.4.1 Live Taps ................................................................................................................................ 6

2.5 Chlorination .................................................................................................................................. 6

2.6 Dechlorination .............................................................................................................................. 7

2.7 Sampling ........................................................................................................................................ 7

2.8 Installation of Closure Piece for New Mains Physically Separated from the System ................... 7

2.9 Implementing a Flushing Program** ............................................................................................ 8

2.9.1 Program Structure, Reporting & Obligations ........................................................................ 9

2.9.2 Regulatory Mandates and Obligations.................................................................................. 9

2.10 Phasing out of Flushing Program ................................................................................................ 10

2.11 Constructed, non-Commissioned Watermain ............................................................................ 10

Flow Diagram - New Watermain Physically Separated from Existing System ........................................ 11

Service Request Form – New Mains Physically Separated from System ................................................ 12

3.0 NEW WATERMAIN ISOLATED BY A VALVE FROM EXISTING WATERMAIN ..................................... 15

3.1 Installation and Certification of Backflow Prevention Device .................................................... 15

3.2 Loading and Swabbing ................................................................................................................ 15

O:\Environmental Services\Compliance and Training\WATER PROCEDURES MANUAL\Current Version\Appendices\Appendix Q Working Documents\Final version\New Watermain Commissioning Requirements.docx April 18, 2017

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3.3 Flushing for Turbidity and Turbidity Testing ............................................................................... 15

3.4 Chlorination ................................................................................................................................ 16

3.5 Dechlorination ............................................................................................................................ 16

3.6 Sampling ...................................................................................................................................... 16

3.7 Hydrostatic Pressure Testing ...................................................................................................... 17

3.7.1 Live Taps .............................................................................................................................. 17

3.8 Flush and 2nd Set of Samples ....................................................................................................... 17

3.9 Removal or Backflow and Opening Valve ................................................................................... 17

3.10 Implementing a Flushing Program** .......................................................................................... 17

3.10.1 Program Structure, Reporting & Obligations ...................................................................... 18

3.10.2 Regulatory Mandates and Obligations................................................................................ 18

3.11 Phasing out of Flushing Program ................................................................................................ 19

3.12 Constructed, Non-Commissioned Watermain ............................................................................ 19

Flow Diagram – New Main Connected to Existing Watermain and Isolated by a Valve ........................ 20

Service Request Form – New Main Connected to Existing Watermain and Isolated by a Valve ............ 21

4.0 SERVICING TO CONDOMINIUMS / PRIVATE TOWN HOMES / INDUSTRIAL, COMMERCIAL, INSTITUTIONAL BUILDINGS ......................................................................................................................... 24

4.1 Backflow Prevention ................................................................................................................... 24

4.2 Private Side Testing ..................................................................................................................... 24

4.3 Final Connection ......................................................................................................................... 24

Service Request Form – Servicing to Condominiums/Private Town Homes/Industrial, Commercial, Institutional Buildings ............................................................................................................................. 25

Figure 1 - 3rd Party Chlorine Residual/Consumption Reporting Form .................................................... 28

Figure 2 - Disinfection Record ................................................................................................................ 29

Figure 3 - Consumption Calculation ........................................................................................................ 30

Figure 4 - Backflow Preventer & Chamber for 21/2" Through 10" Double Check Valve Assembly ........ 31

Figure 5 - Watermain Test By-Pass & Chlorination ................................................................................. 32


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Definitions:

AWWA C651: American Water Works Association Standard for Disinfecting Water Mains

Commissioned: Watermain deemed as “in service” by City of Vaughan staff for the distribution of potable/safe drinking water

Flushing: The sudden rush of water for the purpose of cleaning, scouring or the turnover of watermain

Microbiological test: water samples taken and analyzed for E. coli, Total Coliform, background microorganisms and HPC (heterotrophic Plate Count)

MOECC: Ministry of the Environment and Climate Change

Non-commissioned: Watermain that is not in service and unavailable for distribution of potable/safe drinking water

Operative: Person or entity conducting work. For the purposes of this procedure, an Operative can be either the “Consulting Engineer” for new developments and/or the “Contractor” for capital projects

Operator: A MOECC Certified, City of Vaughan Water Operator (Operator)

Potable (AWWA): Safely Drinkable

Sample Set: A round of samples collected at the same moment in time consisting of 1 (one) or multiple sample point locations.

Sample Round: Consists of two (2) sets of samples.

Swab: A polyurethane foam plug used to clean watermain


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NEW WATERMAIN COMMISSIONING REQUIREMENTS

1.0 INTRODUCTION

1.1 Obligations The City of Vaughan has adopted Ontario Ministry of the Environment and Climate Change’s (MOECC) Watermain Procedure for commissioning all new and temporary watermain. Additional to this procedure, the City of Vaughan also has an obligation to adhere to the most current version of AWWA Standard C651 as required under the Drinking Water Works Permit (DWWP) issued to the City of Vaughan by the MOECC.

Service pipes of 100mm diameter shall be considered as watermain for the purposes of this procedure.

All new mains will be physically separated from the existing water distribution system during the commissioning process. Requests for isolation (by a valve) of the new watermain from the existing water distribution system will be reviewed on a case by case basis and shall be permitted only if physical separation is not a viable option. It will be the responsibility of the Operative (see definitions) to demonstrate that isolation by a valve is the only available option. The decision of the City of Vaughan will be considered final.

A MOECC Certified, City of Vaughan Water Operator (Operator) is required to witness and verify all commissioning activities including:

• Physical Separation • Isolation by a valve • Condominium, Commercial, Industrial, Private Townhomes, Institutional

1.2 Requests All requests for commissioning activities must be scheduled through the Environmental Services Dispatch office by providing a minimum of three (3) business day’s notification to the City. The Applicant shall hand deliver the following information to the attention of the Environmental Services Dispatch Office, otherwise the request will be denied. Requests will not be processed earlier.

A Service Request Form (SRF) must be completed prior to work commencing. These forms are located within this document and can be downloaded from the City’s website at: https://www.vaughan.ca/services/residential/water/Pages/default.aspx.

1.3 Mandatory Submissions Four (4) copies of an 11 x 17 and four (4) copies of a 24 x 36 general plan / key plan must be submitted to the Environmental Services Department located at 2800 Rutherford Road. Drawings must identify street names and highlight the limits by lot/block numbers of the


https://www.vaughan.ca/services/residential/water/Pages/default.aspx

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watermain commissioning area. The general plan must contain ONLY site servicing information (No grading/landscaping, etc.).

The Operative shall submit a disinfection proposal plan to the Supervisor(s) of Water Operations. This plan shall be reviewed and approved prior to any work commencing and will include:

a) The disinfection criteria shall include watermain dimensions, watermain material, disinfection method, contact time, concentration, receiving location and source of water supply.

b) Disinfection site map and key map shall be submitted and will include location of mainline valves, (e.g. V1, V2, etc.), flushing points, sampling points (e.g. S1, S2, etc.), etc.

c) Calculation sheets including chemical volumes, watermain volume, flushing discharge rate and chemical application rates.

1.4 Site Meetings A site meeting with the Water Department is mandatory prior to the start of the commissioning process. Arrangements for the site meeting shall be coordinated by the Operative and shall be made through the City’s Environmental Services Dispatch office.

2.0 NEW WATERMAIN – PHYSICALLY SEPARATED FROM EXISTING WATERMAIN All commissioning and disinfection of new watermains and temporary watermains are to be completed in accordance with Ministry of the Environment & Climate Change’s (MOECC) Watermain Disinfection Procedure and the most recent version of the American Water Works Association (AWWA) Standard C651.

An Operator must be present to witness all steps within this procedure. All requests for scheduling an Operator must be done through the Environmental Services Dispatch office at 905-832-8562 x 8807 or email: [email protected].

2.1 Installation and Certification of Backflow Prevention Device • A backflow preventer (CSA approved B64 standard) shall be installed as per

manufacturers specifications on all by-passes between potable and non-potable water sources (See Figure 4)

• All water used for commissioning purposes taken from the City of Vaughan’s Water Distribution System shall be through the by-pass

• All backflow preventers shall be tested and certified in place by an AWWA Cross Connection Control Specialist

• Backflow preventers shall not be removed until completion of the commissioning project

• Installation of backflow preventer needs proper fittings and appropriate pipe materials. • Any hose connecting risers/pipes/backflow preventers must be of potable water grade.


mailto:[email protected]

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• Backflow preventer must be installed above grade level as per manufacturer’s

specifications.

2.2 Loading and Swabbing • When swabbing branched watermain, a swabbing plan shall be submitted to the City of

Vaughan’s Environmental Services Department at a minimum of five (5) business days prior to the swabbing of the watermain

• All swabs shall be clean and new • Swabs shall be minimum one size larger than the pipe diameter • All swabs shall be marked by the number in the order by which they are launched • All swabs must be collected after launching • For sections of watermain which cannot be swabbed due to a butterfly valve installation

or size/pipe material, the watermain shall be flushed as per AWWA C651 to ensure minimum flushing velocity of 3.0 ft/sec (0.91 m/s) in order to achieve 2.5 to 3.0 log removal of particles.

2.3 Flushing for Turbidity and Turbidity Testing • Watermain shall be flushed to ensure that air and other material have been removed.

This includes all hydrant leads, services and sample point locations • The watermain must be flushed until a turbidity of less than 1.0 NTU is achieved. If

turbidity of 1.0 NTU cannot be achieved within 8 hours of flushing, the watermain shall be reswabbed.

• Turbidity results shall be taken at each sample location and documented on the ‘Disinfection Record’ (Figure 2).

• The flushing velocity shall not be less than 3.0 ft/sec (0.91 m/s) in order to achieve 2.5 to 3.0 log removal of particles as per AWWA C651. If such flow rate is not possible, then flushing at the maximum expected velocity for the line for 2-3 times the volume of the line may be acceptable.

2.4 Hydrostatic Pressure Testing • A safety restrainer is required on riser caps • Watermains must hold at 150 psi (1034 kPa) for 2 consecutive hours, with no leaks and

no additional water added once pressurized. Failure will result in rescheduling of appointment which will include retesting of turbidity and hydrostatic pressure test.

• Calibrated gauges must be used at all times

2.4.1 Live Taps

• Any live tap shall be pressurized at 150 psi (1034 kPa) for 30 minutes with no leaks.

2.5 Chlorination • Continuous feed chlorination will be used and introduced through the by-pass (backflow

protected) using the water from the distribution system


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• Chlorine concentration range should be within the range of 80-120 ppm • Note: appropriate high count instrument shall be used to verify high chlorine

concentrations

2.6 Dechlorination • Appropriate high count instrument shall be used to verify high chlorine concentration • Watermain shall be flushed so that all superchlorinated water is removed from all points

of the watermain that is being commissioned. This includes all hydrant leads, services and sample point locations

• All superchlorinated water shall be neutralized before discharging into the natural environment

• Chlorine residuals shall be taken and must be 1.0 mg/L (combined chlorine) or greater and be reflective of the trend of the City

• After 24 hours of contact time, chlorine high count must be taken at all sample points prior to flushing the watermain. At the end of this 24 hour period, all sample points must meet at least 50% concentration from the original chlorination day. If any one sample fails, then rechlorination of watermain is required.

2.7 Sampling • After final flushing and before the new watermain is connected to the existing water

distribution system, two (2) consecutive sets of passing microbiological samples* shall be taken at least 16 hours apart (as per AWWA C651, section 5.1)

• At least one (1) set of samples shall be collected from every 370 meters (1200 feet) of the new watermain, plus one set from the end of each branch

• Sample points shall be constructed with appropriate fittings • Coordination to obtain samples will be arranged by the Operative • All water distribution samples will be conducted by an Operator • If more than 2 sets of samples are required to obtain release of the new watermain, the

Operative shall reimburse the City for the additional cost incurred by the City resulting from the additional testing and sampling of the watermain section, consistent with City of Vaughan By-Law 054-2014 (or as otherwise amended). This cost will include administration, additional water usage, laboratory fees, staff and resource charges.

*New watermain guidelines for microbiological test results are as follows:

HPC <=250, Background <=25, Total Coliform =0, E.Coli =0

2.8 Installation of Closure Piece for New Mains Physically Separated from the System • Closure pieces shall not exceed 3 meters with minimum connection pieces unless pre-

authorized by the City of Vaughan • Closure pieces shall be planned and scheduled through the City of Vaughan’s

Environmental Services Dispatch office by the Operative.


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• At the time of scheduling with the Environmental Services Dispatch office, a drawing of

the affected area (those impacted by the shutdown) along with a water disruption notice shall be submitted. It is the responsibility of the Operative responsible for the shutdown to provide a minimum 48 hours notification to those that will be affected by the water service disruption.

• Closure piece must be witnessed by a City Inspector and Operator. If there is no City Inspector available, the closure piece must be rescheduled. The Contractor shall not be permitted to work without both of the above present.

• The removal of the temporary connection and the installation of the final connection piping must be witnessed by an Operator

• All piping must be thoroughly cleaned and disinfected using 1% sodium hypochlorite solution or equivalent (Ex. Fittings/pipe shall be sprayed with chlorine solution and pipe hand swabbed with chlorine solution)

• To eliminate the possibility of contamination or the presence of foreign material, trench water must be kept from entering the watermain, by keeping the excavated area dewatered at all times. An air gap must be maintained between pipe and ground water. If the watermain becomes contaminated, the entire watermain commissioning procedure shall be repeated.

• Once the closure piece(s) are complete, the Operator will flush that section to the nearest hydrant or available flushing point, take chlorine residuals and then the valves will be turned on for water quality purposes.

• Watermain that is not commissioned and non-potable shall not be used for construction purposes and no service connections shall be permitted (example: model homes)

2.9 Implementing a Flushing Program** • It is the sole responsibility of the Operative to ensure that the newly constructed

watermain maintains the regulated secondary disinfection (chlorine residuals) as required per Ontario Regulation 170/03. If the City determines that a flushing program is required, a valid copy of the MOECC water distribution Operator certificate must be submitted to the Environmental Services Department and approved prior to the start of the flushing/residual program. Any existing City assets and infrastructure (e.g.: valves, fire hydrants, etc.) shall not be accessed until formal authorization had been given by the City. The City of Vaughan staff reserve the right to request proof of a valid MOECC water distribution Operator certificate from any individual preforming flushing activities on its water system.

• The Operative must submit a flushing plan, clearly identifying flushing points, discharge locations and size of output along with a letter of intent identifying details of AWWA C651, Table 3, and a proposed diagram to include flushing runs, calculation of proposed flushing volumes for each run and chlorine residual sampling/flushing locations.

• During the winter season, road salt must be applied to those areas affected by flushing to ensure public safety.


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• Uni-directional flushing shall be completed at a minimum velocity of 0.91 meters per

second or 3.0 ft/sec (as per AWWA Standard C651 Section 4.4.2.) or as otherwise amended. If such flow rate is not possible, then flushing at the maximum expected velocity for the line for 2-3 times the volume of the line may be acceptable.

• Chlorine residuals shall be taken and be reflective of the trend of the City. • All valves are to be returned to the open position when flushing is not taking place and

all flushing/residual points are to be closed when flushing is not taking place. • The flushing program will commence no later than 15 calendar days from the date that

the final passing sample was taken. • It shall be the responsibility of the Operative to enquire and/or request the laboratory

results from Environmental Services. ** The City of Vaughan is the sole authority regarding approving, changing and terminating all commissioning and flushing programs.

2.9.1 Program Structure, Reporting & Obligations • It is mandatory that flushing programs start with one (1) flushing event and three (3)

chlorine residual events per week. • The City shall be notified of a schedule identifying days of the week these events will

occur. • The Operative shall be responsible for supplying and maintaining meters used at

flushing/residual points. • All flushed water must pass through a water meter at all flushing/residual points. • All water meters shall be approved prior to use by the City. • Every flushing and residual event shall be logged on City issued and MOECC endorsed

document “New Development 3rd Party Chlorine Residual/Consumption” (Figure 1) and supplied to the email address [email protected] within one (1) week of obtaining the results.

• Water consumption will be invoiced to the Developer on a quarterly basis and will reflect the water/wastewater rate for the dates that the water is taken.

• Invoices will include charges for both water and wastewater and a 15% administration fee.

2.9.2 Regulatory Mandates and Obligations • Minimum combined chlorine residuals must be higher than 0.30 mg/L and shall not drop

below the regulated 0.25 mg/L. • Maximum combined chlorine residuals must be below 2.75 mg/L and shall not go above

the regulated limit of 3.0 mg/L. • If a combined chlorine residual of less than 0.30 mg/L or above 2.75mg/L is obtained ,

the City of Vaughan, Environmental Services Dispatch office shall immediately be



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notified by calling 905-832-8562 x 8807, with an immediate follow up sent via email to [email protected].

2.10 Phasing out of Flushing Program • Reduction and phasing out of flushing programs will be determined on a case-by-case

basis. Consideration will be made based on build out, occupancy, presence of dead-ended watermain, and the watermain turnover rate.

• Consumption calculations must be filled out to determine the watermain turnover rate (Figure 3) and must be submitted with the request for program reduction/elimination. Requests can be made by email to [email protected].

2.11 Constructed, non-Commissioned Watermain • If the choice has been made to not fulfill the requirements of a flushing program, it will

be considered constructed watermain but “non-commissioned” unless otherwise identified by the City.

• Disconnection will not be completed by the City. • Physical separation must be established 1 meter outside of the valve chamber. • A letter of intent must be supplied to the City identifying length of time the watermain

will be constructed and non-commissioned. • Each subdivision will be considered on a “case-by-case” basis for approval.




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Flow Diagram - New Watermain Physically Separated from Existing System


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Service Request Form – New Mains Physically Separated from System


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3.0 NEW WATERMAIN ISOLATED BY A VALVE FROM EXISTING WATERMAIN All disinfection is to be completed in accordance with the Ontario Ministry of the Environment and Climate Change’s (MOECC) Watermain Disinfection Procedure and American Water Works Association (AWWA) Standard C651.

City of Vaughan Operators must be scheduled to witness the watermain commissioning process as outlined in this procedure. All scheduling shall be done through the Environmental Services Dispatch office at 905-832-8562 x 8807 or email: [email protected].

3.1 Installation and Certification of Backflow Prevention Device • A backflow preventer (CSA approved B64 standard) shall be installed as per

manufacturers specifications on all by-passes between potable and non-potable water sources (See Figure 4)

• All water used for commissioning purposes taken from the City of Vaughan’s Water Distribution System shall be through the by-pass

• All backflow preventers shall be tested and certified in place by an AWWA Cross Connection Control Specialist

• Backflow preventers shall not be removed until completion of the commissioning project

• Installation of backflow preventer needs proper fittings and appropriate pipe materials. • Any hose connecting risers/pipes/backflow preventers must be of potable water grade. • Backflow preventer must be installed above grade level as per manufacturer’s

specifications.

3.2 Loading and Swabbing • When swabbing branched watermain, a swabbing plan shall be submitted to the City of

Vaughan’s Environmental Services Department at a minimum of five (5) business days prior to the swabbing of the watermain

• All swabs shall be clean and new • Swabs shall be minimum one size larger than the pipe diameter • All swabs shall be marked by the number in the order by which they are launched • All swabs must be collected after launching • For sections of watermain which cannot be swabbed due to a butterfly valve installation

or size/pipe material, the watermain shall be flushed as per AWWA C651 to ensure minimum flushing velocity of 3.0 ft/sec (0.91 m/s) in order to achieve 2.5 to 3.0 log removal of particles.

3.3 Flushing for Turbidity and Turbidity Testing • Watermain shall be flushed to ensure that air and other material have been removed.

This includes all hydrant leads, services and sample point locations • The watermain must be flushed until a turbidity of less than 1.0 NTU is achieved. If

turbidity of 1.0 NTU cannot be achieved within 8 hours of flushing, the watermain shall be reswabbed.



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• Turbidity results shall be taken at each sample location and documented on the

‘Disinfection Record’ (Figure 2). • The flushing velocity shall not be less than 3.0 ft/sec (0.91 m/s) in order to achieve 2.5 to

3.0 log removal of particles as per AWWA C651. If such flow rate is not possible, then flushing at the maximum expected velocity for the line for 2-3 times the volume of the line may be acceptable.

3.4 Chlorination • Continuous feed chlorination will be used and introduced through the by-pass (backflow

protected) using the water from the distribution system • Chlorine concentration range should be within the range of 80-120 ppm • Note: appropriate high count instrument shall be used to verify high chlorine

concentrations

3.5 Dechlorination • Appropriate high count instrument shall be used to verify high chlorine concentration • Watermain shall be flushed so that all superchlorinated water is removed from all points

of the watermain that is being commissioned. This includes all hydrant leads, services and sample point locations

• All superchlorinated water shall be neutralized before discharging into the natural environment

• Chlorine residuals shall be taken and must be 1.0 mg/L (combined chlorine) or greater and be reflective of the trend of the City

• After 24 hours of contact time, chlorine high count must be taken at all sample points prior to flushing the watermain. At the end of this 24 hour period, all sample points must meet at least 50% concentration from the original chlorination day. If any one sample fails, then rechlorination of watermain is required.

3.6 Sampling • After final flushing and before the new watermain is connected to the existing water

distribution system, two (2) consecutive sets of passing microbiological samples* shall be taken at least 16 hours apart (as per AWWA C651, section 5.1)

• At least one (1) set of samples shall be collected from every 370 meters (1200 feet) of the new watermain, plus one set from the end of each branch

• Sample points shall be constructed with appropriate fittings • Coordination to obtain samples will be arranged by the Operative • All water distribution samples will be conducted by an Operator • If more than 2 sets of samples are required to obtain release of the new watermain, the

Operative shall reimburse the City for the additional cost incurred by the City resulting from the additional testing and sampling of the watermain section, consistent with City of Vaughan By-Law 054-2014 (or as otherwise amended). This cost will include administration, additional water usage, laboratory fees, staff and resource charges.


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*New watermain guidelines for microbiological test results are as follows:

HPC <=250, Background <=25, Total Coliform =0, E.Coli =0

3.7 Hydrostatic Pressure Testing • A safety restrainer is required on riser caps • Watermains must hold at 150 psi (1034 kPa) for 2 consecutive hours, with no leaks and

no additional water added once pressurized. Failure will result in rescheduling of appointment which will include retesting of turbidity and hydrostatic pressure test.

• Calibrated gauges must be used at all times

3.7.1 Live Taps • Any live tap shall be pressurized at 150 psi (1034 kPa) for 30 minutes with no leaks.

3.8 Flush and 2nd Set of Samples • The new watermain shall be flushed and 2nd set of samples taken after the pressure test has

passed. The 2nd set of samples shall be taken in accordance with 3.6 Sampling.

3.9 Removal or Backflow and Opening Valve • The backflow preventer shall be removed once the City of Vaughan has confirmed that

both sets of microbiological samples have passed. • An appointment by providing a minimum of three (3) business days’ notice shall be

made with the City of Vaughan’s Environmental Services Dispatch office to coordinate the opening of the valve.

• The valve shall then be opened by an MOECC Certified, City of Vaughan Water Operator once flushing commences.

All scheduling shall be done through the Environmental Services Dispatch office at 905-832-8562 x 8807 or email: [email protected].

3.10 Implementing a Flushing Program** • It is the sole responsibility of the Operative to ensure that the newly constructed

watermain maintains the regulated secondary disinfection (chlorine residuals) as required per Ontario Regulation 170/03. If the City determines that a flushing program is required, a valid copy of the MOECC water distribution Operator certificate must be submitted to the Environmental Services Department and approved prior to the start of the flushing/residual program. Any existing City assets and infrastructure (e.g.: valves, fire hydrants, etc.) shall not be accessed until formal authorization had been given by the City. The City of Vaughan staff reserve the right to request proof of a valid MOECC water distribution Operator certificate from any individual preforming flushing activities on its water system.

• The Operative must submit a flushing plan, clearly identifying flushing points, discharge locations and size of output along with a letter of intent identifying details of AWWA



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C651, Table 3, and a proposed diagram to include flushing runs, calculation of proposed flushing volumes for each run and chlorine residual sampling/flushing locations.

• During the winter season, road salt must be applied to those areas affected by flushing to ensure public safety.

• Uni-directional flushing shall be completed at a minimum velocity of 0.91 meters per second or 3.0 ft/sec (as per AWWA Standard C651 Section 4.4.2.) or as otherwise amended. If such flow rate is not possible, then flushing at the maximum expected velocity for the line for 2-3 times the volume of the line may be acceptable.

• Chlorine residuals shall be taken and be reflective of the trend of the City. • All valves are to be returned to the open position when flushing is not taking place and

all flushing/residual points are to be closed when flushing is not taking place. • The flushing program will commence no later than 15 calendar days from the date that

the final passing sample was taken. • It shall be the responsibility of the Operative to enquire and/or request the laboratory

results from Environmental Services. ** The City of Vaughan is the sole authority regarding approving, changing and terminating all commissioning and flushing programs.

3.10.1 Program Structure, Reporting & Obligations • It is mandatory that flushing programs start with one (1) flushing event and three (3)

chlorine residual events per week. • The City shall be notified of a schedule identifying days of the week these events will

occur. • The Operative shall be responsible for supplying and maintaining meters used at

flushing/residual points. • All flushed water must pass through a water meter at all flushing/residual points. • All water meters shall be approved prior to use by the City. • Every flushing and residual event shall be logged on City issued and MOECC endorsed

document “New Development 3rd Party Chlorine Residual/Consumption” (Figure 1) and supplied to the email address [email protected] within one (1) week of obtaining the results.

• Water consumption will be invoiced to the Developer on a quarterly basis and will reflect the water/wastewater rate for the dates that the water is taken.

• Invoices will include charges for both water and wastewater and a 15% administration fee.

3.10.2 Regulatory Mandates and Obligations • Minimum combined chlorine residuals must be higher than 0.30 mg/L and shall not drop

below the regulated 0.25 mg/L. • Maximum combined chlorine residuals must be below 2.75 mg/L and shall not go above

the regulated limit of 3.0 mg/L.



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• If a combined chlorine residual of less than 0.30 mg/L or above 2.75mg/L is obtained ,

the City of Vaughan, Environmental Services Dispatch office shall immediately be notified by calling 905-832-8562 x 8807, with an immediate follow up sent via email to [email protected].

3.11 Phasing out of Flushing Program • Reduction and phasing out of flushing programs will be determined on a case-by-case

basis. Consideration will be made based on build out, occupancy, presence of dead-ended watermain, and the watermain turnover rate.

• Consumption calculations must be filled out to determine the watermain turnover rate (Figure 3) and must be submitted with the request for program reduction/elimination. Requests can be made by email to [email protected].

3.12 Constructed, Non-Commissioned Watermain • If the choice has been made to not fulfill the requirements of a flushing program, it will

be considered constructed watermain but “non-commissioned” unless otherwise identified by the City.

• Disconnection will not be completed by the City. • Physical separation must be established 1 meter outside of the valve chamber. • A letter of intent must be supplied to the City identifying length of time the watermain

will be constructed and non-commissioned. • Each subdivision will be considered on a “case-by-case” basis for approval.




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Flow Diagram – New Main Connected to Existing Watermain and Isolated by a Valve


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Service Request Form – New Main Connected to Existing Watermain and Isolated by a Valve


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4.0 SERVICING TO CONDOMINIUMS / PRIVATE TOWN HOMES / INDUSTRIAL,

COMMERCIAL, INSTITUTIONAL BUILDINGS

4.1 Backflow Prevention • Once the watermain is commissioned on the City side, backflow and water meter(s) are

to be installed without delay. See Figure 4 for specifications for backflow preventer and chamber for 2-1/2” – 10” double check valve assembly.

4.2 Private Side Testing • Commissioning must be conducted with complete separation at the property line with

an approved certified backflow preventer in place. All water used for commissioning purposes taken from the City of Vaughan’s water distribution system must be through a by-pass. See Figure 5 for specifications on watermain test by-pass and chlorination.

4.3 Final Connection • Any fire service that is connected before the backflow preventer will require an

additional backflow preventer (device is to be the same size as the pipe). See Figure 4 City of Vaughan Engineering Standard Backflow Preventer & Chamber for 2.5” through 10” Double Check Valve Assembly.

• Private services up to 75mm diameter require flushing and chlorine residual testing. The combined chlorine residuals shall not be less than 1.0 mg/L before the City will turn on the service valve. For private services 100 mm diameter and larger, chlorine residual testing and microbiological sampling by an Operator is required. Additionally, analysis of the microbiological samples must be done by an MOECC Certified Accredited laboratory. Copies of the passing sample results from an MOECC Certified Accredited laboratory will be provided to the City within 15 days from the date the last sample was taken and before the service valve can be turned on.

• Passing microbiological results for the private side must be received by the City within 15 days from the date that the sample was taken. Failure to do so will require the commissioning procedure to be conducted again.

If further information is required, please contact the City of Vaughan, Environmental Services, Dispatch office at 905-832-8562 x 8807 or by email at: [email protected]



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Service Request Form – Servicing to Condominiums/Private Town Homes/Industrial, Commercial, Institutional Buildings


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Figure 1 - 3rd Party Chlorine Residual/Consumption Reporting Form


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Figure 2 - Disinfection Record


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Figure 3 - Consumption Calculation


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Figure 4 - Backflow Preventer & Chamber for 21/2" Through 10" Double Check Valve Assembly


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Figure 5 - Watermain Test By-Pass & Chlorination
