HomeMy WebLinkAboutCSD-06-039 - Lower Doon Pumping Station Spill
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Community Services
Report To:
Date of Meeting:
Submitted By:
Prepared By:
Community Services Committee
March 27, 2006
Ken Currier, Director of Operations
Ken Currier, Director of Operations
Ward(s) Involved:
Date of Report:
Report No.:
Subject:
Fairway-Gateway
March 1 0, 2006
CSD-06-039
LOWER DOON PUMPING STATION SPILL
RECOMMENDATION:
For information and discussion.
BACKGROUND:
The City of Kitchener has 22 pumping stations located throughout the city. A pumping station
functions as a collection location in the wastewater collection system to gather wastewater and
pump it into a forcemain which in turn flows into the gravity sewer system. The Lower Doon
Pumping station located at 1820 Old Mill Rd contains the following characteristics.
Station Characteristics provided by CRA Field Verification Report Wastewater Pumping
Facilities, March 2005. Ref. No. 31368 (1)
· Steel pre-fabricated pumping station, built in 1969 with a separate wet well. Dry pit is
accessible through a shaft access via tube ladder.
· Pumps are two dry pit submersible Flygt Type, field tests indicate capacity at 12 Lis and
13 Lis respectively.
· Station inlet via two sanitary sewage pipes.
· Station discharge is a 300mm forcemain.
· Station overflow, 300mm pipe from wet well.
· Standby power is not installed (scheduled for 2006)
· Communication, a single telephone service for alarm purposes via a DCS autodialler.
· Certificate of Approval 3-0204-69-006
Kitchener's pumping stations were subject to an assessment by Consultants in 2003 which
recommended improvements to their infrastructure. During the 2004 capital budget process
$1 ,950,000 was approved to improve the pumping station facilities on a short, medium and long
term priority basis. One of the recommendations was to have stand-by power generators
Report No: CSD -06-039 2
installed at the Lower Doon Pumping Station and the Stoke Drive Station which will be
completed in 2006. This will leave one additional station, Springdale Dr that although not
identified for immediate installation of stand-by power, the options for stand-by power or station
removal will need to be investigated and re -prioritized within the Sanitary Utility capital forecast.
REPORT:
On February 17, 2006 the Lower Doon area of Kitchener experienced a power failure at
approximately 9:20am. The power failure was caused by a tree branch falling across power
lines on Pinnacle Drive between Old Mill Road and Amherst Drive. The power failure interrupted
the pump operation at the Lower Doon Pumping station, as well as 212 other nearby power
customers. The initial power failure was limited to supplying single phase power until
approximately 10:19am at which time all three phases of power were interrupted, allowing hydro
crews to make repairs. Full power supply was restored to the area at 1:21 pm.
An initial assessment of the spill volume was estimated at approximately 18,000 L and a
communication line failure was believed to have prevented staff from immediately responding.
This information was thoroughly investigated and updated information is provided later in this
report.
The pumping station is equipped with an alarm system which is designed to notify a manned
central dispatch monitoring center that the power has been interrupted at the station. The
dispatch center received the call of an alarm at 10:19am but did not notify the pumping station
on-call staff as they misinterpreted the alarm as being for another location that had its power
restored.
This alarm monitoring center is also the dispatch center for the Utilities Operations Division and
during the initial three hour power outage the center received 88 additional alarms, 82 inbound
telephone calls and 120 two way radio communications, all the responsibility of the dispatcher to
coordinate the communication. This level of activity is abnormal for the dispatch center and as
such had only two dispatch staff present to handle all of the calls.
The quantity of spill that was released via the overflow piping from the station was calculated by
determining the inflow rate of approx. 486 L/min. times the power outage of approx 320 minutes
allowing for the station and system capacity of approx. 67,520 L resulting in a spill of up to
88,000 L. The inflow rate and system capacity were determined by selecting another similar day
one week later and shutting down the pumps at the station to determine the inflow rate and the
time to reach system storage capacity.
The configuration of the pumping station property contributed too much of the spill being
contained on the property in two depressions adjacent to the Grand River. The river is
approximately 40 meters east of the overflow outlet. The spillage that was contained in the
depressions was pumped back into the station during the site cleanup operation. Measuring the
volume of the two depressions, containing 15,000 L and 35,000 L respectively this 50,000 L
pump back was deducted from the station spill resulting in a spill to the Grand River of up to
38,000 L.
Operations Pumping Station on-call staff were eventually notified by the Grand River
Conservation Authority at approximately 2:OOpm and response staff were immediately deployed.
The station was manually restored by 2:45pm and cleanup efforts began immediately. While the
station was being restored Operations Management staff contacted the Ministry of the
Environment Spills Action Center, the Grand River Conservation Authority, the municipalities of
Cambridge and Brantford and the Region of Waterloo's Public Health Department. Confirmation
Report No: CSD-06-039
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was received from the Region of Waterloo's Public Health unit that the downstream private well
owners abutting the Grand River were not at risk from the spill. A call was also placed to the
local area representative from the Ministry of the Environment.
Site Impact
Once the pump back operation was complete staff were able to inspect the property and
manually collect any solids that were visible. Site inspections will continue regularly as melting
snow may expose more solids. The quantity of solids that were released in the spill were
minimized as the station inlet chamber contains a bar screen designed to filter the solids. This
screen is cleaned on a regular basis.
Also snow fencing was installed in the area of the spill to keep residents and animals out of the
area until precipitation and ground filtration removes any remaining residue from the spill.
FINANCIAL IMPLICATIONS:
Once the station was brought back on line and the site cleanup was complete staff met to
determine what measures could be taken to ensure a repeat of this spill is minimized. A
summary of the preventative measures that are to occur include:
1. Installation of a standby power generator will take place between May and October of
2006 as a departmental priority. Site costs approximately $350,000.
2. Station alarms will include simultaneous calls to the central dispatch center and to a pager
carried by on-call staff. This technology which includes a dedicated SCADA system for
pumping stations will be installed during the installation of the stand by power generator
and utilized at all pumping stations by early 2007 at a cost of approximately $140,000.
3. Education and training sessions for dispatch center staff will focus on understanding
station alarms and interpretation of priority alarms.
4. Mandatory contact and logging of all pumping station alarms by dispatch staff.
5. Reduction adjustment of workload for dispatchers responsible for alarm monitoring and
response.
6. Updating of pumping station identifiers to eliminate station name confusion.
7. Field trips to stations by dispatchers.
8. Complete review of emergency procedures for each station.
9. Updating of emergency contact information for all agencies and contractors.
The additional costs identified have been previously approved and are included in the 1 0 year
capital forecast for the Sanitary Utility. Any additional training and procedural costs will be
absorbed by the operating divisions.
COMMUNICATIONS:
Communications were provided to the media at the time of the spill and an additional media
release has accompanied the release of this report. A formal report of the incident has also
been forwarded to the Ministry of the Environment for their review.
CONCLUSION:
This incident has re-enforced the need to place a high value on communication and systems
between all levels of our organization. Kitchener is in a fortunate situation as to not have
experienced any spills from our pumping stations into the Grand River in past memory and the
foresight of staff to identify priorities for our pumping station infrastructure has proved beneficial
Report No: CSD-06-039
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to address station problems. Although the timing of the installation of a back-up generator at
this site could have impacted this spill, Kitchener is well positioned to ensure power supply and
improved communications for all stations are installed.
Ken Currier
Director of Operations
AP