City of London Emission
Reporting
The City of London is required to report emissions to Environment Canada under the Canadian Environmental Protection Act 1999, Part 3 Information Gathering and as amended in the
Canada Gazette Notice. Further details on reporting can be found on the
Environment Canada
website.
The City of London is required to report for the:
- Adelaide Pollution Control Plant
- Greenway Pollution Control Centre
- Oxford Pollution Control Plant
- Pottersburg Pollution Control Plant
- Vauxhall Pollution Control Plant, and
- W12A Landfill
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Table of Contents
Supplementary Notes
2011 NPRI Emission report
NPRI data is used on some web sites to
identify the "largest polluters". The listing of a quantity in total tonnes does
little to differentiate between contaminants and their effects on the
environment and actually masks contaminants with lower reporting thresholds such
as dioxins (measured in grams), mercury and arsenic (measured in kilograms).
Sewage treatment plants and landfills are operated by the City on behalf of and
for the betterment of the community. "Environmental degradation" is greatly
reduced when the systems are in place to handle liquid and solid wastes from
residences and businesses. While the municipality strives to improve performance
on an ongoing basis, municipal facilities are not the source of these pollutants
and pollution prevention best begins at source with the individuals and
businesses who use these services.
Brief Explanatory Notes on Compounds Listed in this
Report
A report on the quality of the Thames
River and a report on performance of the sewage treatment plants can be found at
http://www.london.ca/d.aspx?s=/Sewer_and_Wastewater/Thames_River_quality.htm
.
The NPRI data is broken down into Releases (discharges to the environment) and
Disposal (material captured and put into landfills or other final treatment
methods. The largest tonnage compound reported from the sewage treatment plants
is Nitrate (992 tonnes). The City of London sewage treatment plants utilize
bacteria to convert ammonia, which, in significant concentrations, is toxic to
fish, to nitrates and this is called nitrification. The city sewage treatment
plants convert over 96% of the ammonia to nitrates. Ammonia and nitrates are
nutrients and are used to fertilize farms and gardens.
There is no Ontario surface water criterion for nitrates; however, there is a
drinking water criterion of 10 mg/L. The City of London monitors nitrate levels
upstream of the City on two branches of the Thames River and the average for
2011 was 5.1 mg/L. Downstream of the City the average for 2011 was 5.3 mg/L. The
implications are that the nitrates are not above drinking water criterion. There
is no Ontario surface water criterion for nitrates but a proposed CCME criterion
is 2.9 mg/L. The criterion is based on Lake trout which do not spawn in rivers.
Levels of nitrate in Lake Huron and Lake Erie range from 0.2 to 0.8 mg NO3-N/L
based on City of London water supply data. The Maximum Acceptable Toxicant
Concentration (MATC) for Rainbow trout is 8.6 mg NO3-N/L due to delay of sac fry
to the swim-up stage. Rainbow trout are found in lakes, and move to rivers and
streams in the spring and fall. The average concentration of nitrates in the
spring and fall between 2006 and 2010 inclusive is less than 6 mg NO3-N/L in the
Thames River entering or leaving the City of London. Levels of nitrates are
below the MATC for rainbow trout.
While the amount of ammonia released in 2011 is 85 tonnes from the pollution
control plants the average concentration over the year was 0.77 mg/l which is
well below the City compliance limits of 3 to 5 mg/l. This is the residual
amount of ammonia that remains after nitrification and it is low enough that it
is not toxic to fish in the concentrations discharged from the City’s sewage
treatment plants into the river.
The City’s sewage treatment plants remove 90% of phosphorous and dispose of it
as ash at the St. Mary’s Cement plant in 2011. The balance of the phosphorous in
2011, released into the river, is 34 tonnes. Phosphorous is not toxic but is a
nutrient that can enable excessive algae and plant growth. The sewage treatment
phosphorous is approximately 17% of the phosphorous found in the Thames year
based on annual averages. Other sources of phosphorous include agriculture and
lawn fertilizer.
Other parameters reported in kg include lead, arsenic, cadmium and mercury.
Concentrations in the sewage plant effluent for these metals are 1 ug/L or less
(parts per billion). There is little that can be done at the sewage treatment
plant to reduce levels further. Regulating consumer products that have trace
metals would be one method of pollution prevention but this would have to be
done at the federal level. An example is cadmium in bleach. Dentists have been
required to install ISO certified amalgam separators to reduce mercury
discharges.
The W12A landfill emitted 52 tonnes of Carbon monoxide in 2011 based on emission
factors from the United States Environmental Protection Agency. Ammonia released
in runoff from the landfill was 0.06 tonnes and ammonia from leachate sent for
treatment at the Greenway Pollution Control Centre was 74.5 tonnes and releases
after treatment are noted above.
The Canadian Council of Ministers of the Environment (CCME) reported (October
2004) that there were 195 grams of Dioxins and furans discharged from 26 sector
groups per year. Of the 26 sectors, incineration was responsible for 2.4% of the
dioxin and furan emissions or about 4.6 ITEQ grams. This is a decrease of about
90% from numbers reported in 2001. The Incinerator sector includes Municipal
solid waste, Hazardous waste, Hospital waste and sewage sludge. Sewage sludge
incinerators accounted for 0.05 grams of Dioxins and furans or 1% of the
Incinerator sector. There are 6 sewage sludge incinerators in the group and the
Greenway Incinerator has the lowest dioxin and furan emissions of the group. The
CCME has come out with a dioxin and furan standard for sewage sludge
incinerators and Greenway emissions are below the standard.
As a comparison, an October 2004 CCME report suggests that burning of domestic
waste in barrels represented between 12 and 22% of the Canadian emissions of
dioxins and furans (an emission level similar to the Incineration sector).
Hexachlorobenzene was not detected at the Greenway Incinerator and a value of
the detection limit 0.08 ug/m3 was used for the reported emission estimate.
Sewage treatment plants and landfills are operated by the City on behalf of and
for the betterment of the community. "Environmental degradation" is greatly
reduced when the systems are in place to handle liquid and solid wastes from
residences and businesses. While the municipality strives to improve performance
on an ongoing basis, municipal facilities are not the source of these pollutants
and pollution prevention best begins at source with the individuals and
businesses who use these services.
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