Spill Management for the Toronto AOC:
The City of Vaughan Study
Sponsored by
Ministry of Environment and Energy
Introduction
One of the water pollution sources in the Toronto Area of Concern (AOC) is spills. Between 1988 and 2000,
there were 2475 oil spills (estimated 830,600 L) and 1584 chemical spills (estimated 1,125,000 L) in Toronto,
Richmond Hill, Markham, and Vaughan. Spills negatively affect air, water, and soil and their associated terrestrial
and aquatic species. Recognizing the Toronto AOC’s restoration targets and priorities, Government of Canada’s
Canada’s Great Lakes Sustainability Fund (GLSF), the Toronto and Region Conservation Authority (TRCA), the
Town of Richmond Hill, and the Ontario Ministry of Environment and Energy’s Spills Action Centre (SAC)
sponsored this study to evaluate spill characteristics and management options for southern York Region and the City
of Toronto. The specific objectives of this study are to:
 Review spill legislation
 Compile a spill database
 Analyze spill event characteristics
 Evaluate preventive and control options for municipalities
This factsheet focuses on the study for the City of Vaughan. Similar factsheets for the Town of Markham,
Town of Richmond Hill, and the City of Toronto are published separately.
Phase 1: Spill legislation
The legislative framework behind spill management of materials (including oil) in Canada spans all levels of
government, all the way to individual responsibility of the dischargers themselves. Regulations for prevention
planning, notification to the proper authorities, clean-up and restoration of the natural environment, manifest
themselves in many Federal Acts including the Canadian Environmental Protection Act, the Canada Shipping Act,
the Emergency Plans Act; Provincial Acts such as the Environmental Protection Act (Ontario) and the Ontario
Water Resources Act; and municipal by-laws. The main focus of the regulations prescribed by these acts and others
is to maintain the integrity of the natural environment and to prevent any adverse effects to the natural environment
by spills.
Municipal sewer use by-laws can be effective ways to promote pollution prevention since they can regulate
activities that prevent spilled materials from entering sewers. However, there are not many cases where this is
being done. The City of Vaughan has currently no sewer use bylaws adopted particularly for spills. The Wastewater
& Drainage section (WDS) is responsible to monitor and maintain infrastructure for the collection of wastewater and
to control the environmental impact of its storm management system. The WDS provides the following services:
clean-up of spills of hazardous materials; investigate sewer back-ups; investigate odors from drains; and yellowfish
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road program. Liquids such as engine oil, paint, and cooking oil, contaminate and clog sewers creating expensive
maintenance costs. The City of Vaughan advises residents not to pour down these materials into drains and
recommends that these materials be taken to the hazardous waste depot at Toronto’s Keele Valley Landfill site.
Phase 2: Compilation of spill database
SAC records the majority of its spill events through a province wide toll-free number on a 24 hour-per-day
basis. All occurrences reported to SAC are recorded on a computerized database management system called the
Occurrence Report Information System (ORIS). Each occurrence is classified into one of four different types of
occurrences: Spills, Notifications, Complaints and Other. The spill database includes date, municipality, owner
name, address where a spill occurs, material type, estimated volume, description of the event, source, sector, reason,
cause, estimated cleanup percentage, and impact. This database was developed primarily for the Ministry. In order
to use the spill data for the purpose of municipal spill management, additional works are necessary. A general
methodology to compile a spill database for municipal spill management is listed below:
1. Request spill data from SAC and compare with municipal spill records such as occurrence, volume,
material types, cause and reason, cleanup, and impact.
2. Scrutinize spill data in terms of consistency and eliminate erroneous information.
3. Create new fields to describe spill records such as location (roads, parking lots, storage yards, etc), material
properties (density, boiling point, hazardous material classification, etc.) and so on.
4. Assemble digital municipal infrastructure information such as sewershed, outfall locations, drainage system
types, local environmental sensitive areas, etc.
5. Geocode municipal addresses where spills occur.
6. Compile all information into a database where updating, importing, exporting of data can be performed
easily.
Phase 3: Characterization of spills
Over the period from 1988 to 2000, the annual number of oil spills in the City of Vaughan (released to
waterways) ranged from 11 to 38 while the annual oil spill volume varied between 1,320 to 20,670 L. The
following spill statistics are derived from the SAC’s spill data between 1988 and 2000. The average annual number
of oil spills was 25 and the average spill event volume was approximately 430 L. However, the range of oil spill
event volume varied between minimal to 13,500 L. The top four frequent spill locations were roads (104 spills),
service stations (45 spills), hydro related facilities (33 spills), and parking lots (22 spills). Arterial (82 spills) and
collector (35 spills) roads also had a high frequency of oil spills. Diesel fuel (163 spills), gasoline (40 spills), and
hydraulic oil (34 spills) were the most frequent oil types. In terms of spill event volume, diesel oil was the largest
spill material. The larger oil spill events occurred at CN railways (13,500 L event), roads (1,000 L event) and
parking lots (675 L event). Oil spills at other locations were generally less than 400 L. Soil contamination and water
pollution were the primary environmental impacts of oil spills in the City of Vaughan. However, soil contamination
due to oil spills is likely to impact on the local environment while water pollution associated with oil spills may be
transported downstream resulting in greater environmental damages. The primary causes of oil spills were related to
human errors and equipment failure. About two-thirds of the oil spills in Vaughan were cleaned up after their
occurrence.
To evaluate the spatial distribution of oil spills in Vaughan, oil spills with municipal addresses (about 27%)
were geo-coded and mapped using ArcView GIS. As shown in Figure 1, most oil spills were found in the urban
core within the Don and Humber River watersheds. No oil spills were found at the TRCA’s Environmental
Sensitive Areas. It is noted that many of the original SAC’s spill records do not have good descriptions of locations
and addresses. Thus, the spatial analysis in this study is only a preliminary evaluation. Additional works such as
geocoding spill locations manually using Global Position System should be conducted to improve the quality of spill
analysis.
In the City of Vaughan, two stormwater ponds (i.e. pond 26 and 43) in the Don River watershed were found to
be susceptible to oil spills (Fig. 2). Pond 26 is a quantity pond located near Rutherford Road and Keele Street while
Pond 43 is a quality/quantity pond located near Major Mackenzie Road and Jane Street. Depending upon further
site investigations, retrofitting these ponds for oil spill control may provide some protection against oil spills at the
western tributary of Don Rivers near Keele Street. Seven potential locations for retrofitting oil interceptors are
identified in Fig. 3. These locations are determined by identifying public lands downstream of the spill prone
outfalls. Further site investigations are necessary to screen the most appropriate locations for retrofitting oil
interceptors.
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Figure 1 Selected spill locations in the City of Vaughan
Figure 2 Oil spills which enter the stormwater drainage systems in the Don and Humber River watersheds
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Figure 3 Potential oil spill control locations in the Don and Humber River watersheds
In the Region of York (all 9 municipalities), there were 432 chemical spills between 1988 and 2000. The
frequency of chemical spills reached the highest level in 1993 and occurred mostly in summer months. The
following spill statistics are derived from the SAC’s spill data between 1988 and 2000. Among all these chemical
spills, the more frequent chemical types were used motor oil, smoke, waste oil, oily water, and mineral acids. In
terms of volume, natural gas, Chlorinated fluorocarbons (CFC)and Refrigerant Hp-80 were the largest, because of
their gaseous form, while waste oil and oily water were the second largest in volume. Most of the spills originated
from industrial plants, storage facilities, and transportation vehicles. Pipelines, industrial plants, and storage-related
spills produced the larger volumes. General manufacturing and food processing sectors had frequent spills while the
petroleum sector produced the largest spill event volume. Parking areas, storm sewers, roads, and water bodies were
frequent spill locations. Water pollution (e.g., watercourses, surface and ground water) and soil contamination were
the most frequent impacts of chemical spills while the larger chemical spill event volumes were associated with air
pollution. Leakages at containers, fuel tanks, and valve fittings were the frequent causes of chemical spills while
leakages at valve fittings resulted in the largest chemical spill event volumes.
Phase 4: Management options for spills
Municipalities, such as the City of Vaughan, should adopt sewer use by-laws that regulate industrial discharges
to sewers and require industries to prepare pollution prevention plans. Additionally, municipalities should
coordinate with provincial and federal agencies and industrial associations to promote spill education and training.
Employee training and preventive maintenance should be emphasized in training programs for spill-prone sectors
(e.g., petroleum and transportation). Spill prevention should also be promoted to residents in older residential areas
and institutions where heating oil is still used.
For the control of oil spills at individual facilities, containment structures and oil/water interceptors can be
conceivably used. However, sizing of oil separator devices is currently not based on oil spill characteristics, as
derived from studies described in this fact sheet Based upon the statistical properties of oil spill event volumes, this
study has developed sizing criteria for these control measures.
Installation of large oil spill control devices may be required at spill-prone sewer outfalls to prevent spilled oil
from discharging directly to watercourses.
Another control option is to retrofit stormwater ponds that are
susceptible to oil spills. However, these spill control options (at either stormwater ponds or outfalls) are untested and
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needed to be developed and demonstrated. Further investigations are needed to determine recommendations for any
outfall control options.
For chemical spills, the management options should focus primarily on pollution prevention, as control
measures generally require expensive wastewater treatment techniques.
Based on the findings of this study, the following recommendations are made.
1. The spill reporting and recording system can be further improved by compiling detailed and consistent
reports. For instance, spill event volumes should be reported in consistent units and detailed description of
cause and reason should be given. Additionally, spill characteristics such as locations, road types, and
occurrence of rainfall should be reported, as this information can be used to develop sizing criteria for spill
control devices. To facilitate spatial analysis of spill characteristics, addresses of spills should be geocoded by inspectors using Global Position System.
2. Public education of spills should be part of spill management planning by all levels of government. This
will improve public awareness of spills and assist the reporting of spills.
3. As human error and equipment related failure are the primary reasons of spills, spill prone industries should
emphasize preventive maintenance and improved employee training.
4. Municipalities such as the City of Vaughan can take a lead role in spill prevention. By establishing a
municipal sewer use by-law, a municipality can require industries to prepare pollution prevention plans as
well as regulate the discharge of toxic chemicals to sewers.
5. A comprehensive spill control strategy should be developed for each spill prone watershed. Both on-site
and off-site facilities should be considered for spill control. On-site oil/water separators should be installed
in spill-prone commercial and industrial facilities. At the downstream end of a spill-prone sewershed,
either a stormwater pond retrofitted for spill containment or an outfall oil-water separator should be
considered. This strategy should be integrated with land use approval and municipal capital programs.
6. Stormwater management criteria for spill prone commercial and industrial sites should include a spill
control volume that reflects the statistical properties of spill event volume at these facilities.
7. Stormwater ponds and outfalls that are prone to spills should be investigated further for retrofit potentials.
For additional information, please contact
James Li, Ph.D., P.Eng.
Email: jyli@acs.ryerson.ca
Phone: (416) 979-5000 Ext. 6470
Fax: (416) 979-5122.
References
Li, J. 2000a. Sizing criteria for oil separators in urbanized areas. Proc. 6 th Environmental Specialty Conference,
CSCE, 496-503.
Li, J. 2000b. A GIS planning model for urban oil spill management. Proc. 1 st World Water Congress of the
International Water Association, Paris, France.
Li, J. and P. McAteer. 2000. Urban oil spills as a non-point pollution source in the Golden Horseshoe of Southern
Ontario, Water Quality Research Journal of Canada, 35:331-340.
Li, J. 2002. Spill Management for the Toronto AOC: The City of Toronto Study. Report and factsheet prepared
for the Great Lakes Sustainability Fund, Burlington, Ontario, Canada.
Li, J. 2002. Spill Management for the Toronto AOC: The City of Vaughan Study. Report and factsheet prepared
for the Great Lakes Sustainability Fund, Burlington, Ontario, Canada.
Li, J. 2002 Spill Control Study for the Humber Creek subwatershed. Report and factsheet prepared for the Great
Lakes Sustainability Fund, Burlington, Ontario, Canada.
Li, J. 2002. Spill Management for the Toronto AOC: The Town of Markham Study. Report and factsheet
prepared for the Great Lakes Sustainability Fund, Burlington, Ontario, Canada.
Li, J. 2002. Spill Management for the Toronto AOC: The Town of Richmond Hill Study. Report and factsheet
prepared for the Great Lakes Sustainability Fund, Burlington, Ontario, Canada.
Toronto and Region Conservation Authority (TRCA). 2001. City of Vaughan Stormwater Retrofit Study.
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