Environmental Services Committee/

Comité des services de l’environnement

 

Minutes / Procès-verbal

 

Tuesday, 22 May 2001, 9:30 a.m.

Le mardi 22 mai, 9h30

 

Britannia Water Purification Plant /

Usine de purification de Britannia

 

 

 

Members Present / Membres présents:

Councillors/Conseillers P. Hume (Chair), P. McNeely (Vice-Chair), G. Hunter, H. Kreling and D. Thompson

 

Members Absent / Membres absents:

Councillors/Conseillers G. Brooks, D. Deans, C. Doucet and W. Stewart

 

Others present / Autres présents: Councillors/Conseillers R. Bloess and J. Stavinga

 

 

PRESENTATION/

PRÉSENTATION

 

TRANSPORTATION, UTILITIES AND PUBLIC WORKS /

Transport, services et travaux publics

 

1.                  TOUR OF BRITANNIA WATER PURIFICATION PLANT

VISITE DE L’USINE DE PURIFICATION DE BRITANNIA

 

 

The Committee departed from City Hall at 9:30 a.m. on an OC Transpo bus.  The bus passed by the Fleet Street Pumping Station.

 

Dixon Weir, Drinking Water Services Manager provided an on-the-bus presentation about the Fleet Street Pumping Station.

 

The following history, provided by John Van Den Oever, Pilot Plant Operator, Water Quality Section, is a brief summary of the development of the Fleet Street Pumping Station.

 

The City of Ottawa was selected by Queen Victoria as the seat of government of Canada in 1857.  This was a period of great economic and population growth in the Ottawa region.  With the commencement of construction of the Parliament Buildings in 1859, came demands for more civic services, which were unavailable in this rough lumber and agricultural community.  On July 4, 1859, the City of Ottawa commissioned the respected Engineer, Thomas Coltrin Keefer, to design a municipal water and sewage system.  Mr. Keefer prepared the preliminary report, proposing that an aqueduct be built to conduct water 3,000 feet upstream of the Chaudiere Falls to a reservoir atop Barrack (Parliament Hill), from which the town would be supplied by gravity flow.  The plan would have cost $300,000.00.  Combined with a sewage disposal system, the total cost was to be $1,675,800.00.  The amount was considered prohibitive, and no action was taken.

 

In August 1868, a public meeting was held in City Hall to get an expression of opinion from the Ottawa ratepayers on the desirability of constructing water works.  The meeting soon became raucous: all the water carriers, whose businesses would have been negatively affected by water works, were in attendance and were undeniably vocal in their expression of dissatisfaction with any such plan.  Ratepayers in attendance pointed out that no other city in Canada with a population of 20,000 or greater was without water works.  The motion affirming a water works for Ottawa was carried by a large majority.  In a heated discussion that followed, the water carriers became “turbulent” and a motion to defer action was carried by just as large a majority as the first motion favouring the water works.  The meeting broke up in chaos with a large brawl spilling out onto the street.

 

Thomas Coltrin Keefer was once again commissioned to develop proposals for a water works.  In his report he recommended the construction of a pumping station near the Chaudiere Falls.  By utilizing the inherent waterpower to drive pump turbines, water would be propelled into the distribution system.

 

The City Water Works Committee endorsed Keefer’s plan, but it failed to act on the plan.

On March 6, 1872, spurred by the disastrous fires of Chicago and Carleton County of 1870-1871, Ottawa City Council passed a by-law for the establishment of a water works.

 

During the years of 1873-1874, construction was under way on the Queen Street Pumping Station, which was later known as the Fleet Street Pumping Station.

 

Construction of Aqueduct No.1 and the distribution system were begun in 1873.

 

Until 1913 all pumping in the Ottawa Water Works was done by water wheels driving reciprocating pumps located at this station.  In 1874, the Queen Street Pumping Station housed pumping units Nos. 1, 2 and 3 delivering a maximum of 3 million gallons of water per day

(13.6 ML/d).  It is a substantial limestone structure and constitutes the central portion of the existing pumping station today.  It was erected at a cost of $28,000 and continues today as a central cog in the Ottawa-Carleton water distribution system.

 

In the ensuing years, the pumping station was expanded several times.  By 1899, the building had been extended twice and a total of eight pumping units had been installed, bringing the total capacity to 35 million gallons/day (159 ML/d).

 

During the year 1911, the first of two major typhoid epidemics occurred in Ottawa.  The citizens of Ottawa were then unaware of the fact that the cause of the outbreak of typhoid was not attributable to the natural water of the Ottawa river, but to the influent of sewage directly into the clear water pipe which supplied drinking water to the City.

 

On February 1st, 1911 a plant was installed at No. 1 pier (Nepean Bay/ Aqueduct No. 2 junction) for the disinfection of the water by hypochlorite treatment.

 

In 1912, inadequacies in the power water aqueduct were recognized and a second aqueduct was constructed.  Within moments of its official opening in April of 1912, a rupture occurred in the concrete section of pipe within the aqueduct.  It was opened unceremoniously by an operator weeks later after hasty repairs were made.  Within a few months, Ottawa experienced a second serious typhoid epidemic due to multiple ruptures in aqueduct No. 2 and the new steel intake pipe, which ran along the bottom of its north wall.

 

Following the two outbreaks of typhoid in 1911 and 1912, construction of a sedimentation basin and hypochlorite of lime treatment facility on Lemieux Island began in 1913 to combat the influence of the infectious agents introduced into the water intake pipe.

 

It was not until 1915 that a new electric pumping station on Lemieux Island was required to augment the city water supply derived from the Fleet Street Pumping Station.

 

By 1931, the City’s first water filtration plant was constructed on Lemieux Island.  At that time a 1300 mm diameter water main was constructed from the filtration plant to Fleet Street, treated water being transmitted by gravity through the main for pumping into the city system by the aging, but still operational, hydraulic pumping station.

 

DECISION TO REHABILITATE AND RETAIN

Over the years since 1912, the structural appearance and functioning of the station did not change substantially.  During the 1940’s, all of the original water wheels and reciprocating pumps were replaced with modern turbines and centrifugal pumps.

 

By 1969, a decision was made to abandon the station because of the need for costly remedial repairs, but in 1978, this decision was reversed as a result of the energy crisis of the 70’s.  Feasibility studies indicated that the facility could be repaired, restored and automated at a cost, which could be quickly recovered through energy and labour savings.

 

REHABILITATION (1982)

The installed pumping capacity in 1975 was 236 ML/d, but major hydraulic constraints had restricted actual pumping capacity to approximately 55 ML/d.  Prior to rehabilitation, a variety of operating innovations developed by our own staff resulted in an increase in station output of over 100 % in the period 1975 to 1981.

 

The actual rehabilitation works were conducted in 1982, the station being out of commission for six months.  This was the first extended outage of the station in its 108-year history.

 

DESCRIPTION OF EXISTING FACILITY

A new control structure at the head of the covered aqueduct regulates the flow of water through the aqueduct as required by the turbines at the pumping station.  Two motorized sluice gates, each 2.7m x 2.7m, automatically modulate to maintain a required water level in the head pond adjacent to the pumping station structure.  The old original open aqueduct has been abandoned, the new covered aqueduct being sufficient to supply all the necessary power water requirements.

 

Power water from the forebay at elevation 170.6 m supplies any of five turbine units through stone and concrete channels.  Each channel is fitted with trash racks and sluice gates.

 

The turbines are located in concrete chambers.  Each turbine is fitted with a wicket gate control structure to regulate inlet water flow, a vertical draft tube to collect discharge water flow, and a vertical shaft to transmit power to the operating flow immediately above.  Since the turbines operate at a relative slow speed, each turbine shaft is fitted with a speed increaser, the resulting power being transmitted at the desired speed directly to the shaft of the connected centrifugal pump.

 

A total of five turbine-pump units are installed, two at 760 HP, 77 ML/d each and three at 300HP, 27ML/d each.  The total installed capacity is 2420 HP, 236 ML/d.

 

Power water discharges from the turbines through vertical draft tubes to the tailrace, a channel cut out of solid rock underneath the pumping station structure.  The floor of the tailrace is at elevation 133 m, some 12 metres below the head pond water level.  Under normal operations, the water level in the tailrace is at elevation 143.6 m, the net head across the turbines being 8 metres.

 

Water to be pumped by this station originates from the Lemieux Island Water Filtration Plant, transmitted by gravity for a distance of some 2400 metres via two watermains.  An important feature of this operation is a surge protection system designed to divert water to waste in the event of excessive pressures caused by sudden flow changes.

 

The normal mode of operation is remote control and monitoring from the Lemieux Island Water Filtration Plant with local manual override for each individual turbine/pumping unit.

 

REFERENCES

The Fleet Street Pumping Station by S. Bonk, P.Eng. (Sept.26, 1984)

The historical Development of Lemieux Island - Regional Municipality of Ottawa-Carleton (August 1998)

 

 

Upon arrival at the Britannia Water Purification Plant, the Committee received an information kit.  The kit includes the following information, and is on file with the City Clerk:

 

Following Mr. Pat McNally, the Director of Utility Services’ opening remarks, the Committee received a presentation on Drinking Water Treatment by Mr. Dixon Weir, the Manager of Drinking Water Services.  Detailed information on the presentation is on file with the City Clerk.

 

The Committee then went on a tour of the Britannia Water Purification Plant and Pilot Facility guided by Mr. Ian Douglas, the Process Engineer - Water Quality.  Detailed information on the following stations is on file with the City Clerk:

 

In his closing remarks, Councillor Peter Hume, Chair of the Environmental Services Committee thanked staff for the very impressive tour.  He felt that it is very important that Councillors understand the process in order to instigate a higher level of confidence in the safety of drinking water to the Ottawa citizens; and to allow and encourage staff to continue this process.

He suggested that staff make arrangement for the Committee to visit some other facilities, for example, the Trail Road Landfill Site.

 

 

NEXT MEETING

PROCHAINE RÉUNION

 

12 June 2001

Le 12 juin 2001

 

 

ADJOURNMENT

 

The Committee adjourned the meeting at 12 Noon.

 

 

 

 

 

 

 

 

      _________________________                                        _________________________

      Committee Coordinator                                                      Chair