What are phosphates?
Phosphorus is a nutrient vital to human, animal, and plant life.
It is one of the most common substances in our environment, naturally occurring
in our food, water, and bodies, as well as, in human and animal waste.
In nature , phosphorus usually exists in the form of an organic or inorganic
phosphate molecule. Organic phosphates are formed from plant or
animal tissue. Inorganic phosphates are like minerals and which are an
essential nutrient for plant growth. Both organic and inorganic phosphate
can be dissolved in water or attached to other particles in water.
Why is too much phosphorus bad?
Too much of an increase of phosphorus in freshwater systems can set off
a whole chain of undesirable events in a stream. Under the right
conditions too much phosphorus in streams, rivers and lakes can lead to
accelerated plant growth, algae blooms, low dissolved oxygen, and the death of
certain fish, invertebrates and other aquatic animals.
Because phosphorus is a nutrient, algae thrive on it. Algae can spread across
the water surface in floating blooms that prevent sunlight from reaching the
underlying plants. As a consequence, plants die and decompose. Micro-organisms that feed on dying plants also thrive
and consume too much of the oxygen in the water body, leaving fish and other
aquatic life to die.
The ban on phosphates in laundry and dishwashing soaps was part of the
Great Lakes Water Quality Agreement signed by Canada and the United States in 1972
and renewed in 1978.
The ban is credited for reducing phosphorus levels in the Great Lakes by 50 per
cent in the 10 years that followed.
With frequent occurrences of algae blooms this past summer there is a new move
to ban phosphorus in dishwasher detergents with the Provinces of Manitoba and
Quebec raising concerns. Washington State passed a law in March 2006 limiting
the amount of phosphates in household dishwasher detergent sold in that state to
0.5%, or a trace amount, effective July 1, 2010 (in most of the state).
Maryland, Vermont, Minnesota and Illinois have followed Washington State's lead.
On September 26, 2007, the Canadian Consumer Specialty Products Association
news release committing to limit the phosphorus content in household
automatic dishwashing detergent to 0.5 per cent by weight effective July 2010.
On February 15, 2008 the Minister of the Environment and
Minister of Public Works and Government Services announced action on restricting
the level of phosphates in laundry and dishwasher detergent. For more
information, see the
Consumer Reports article
evaluated different dishwasher detergents and determined that environmentally friendly detergents
with enzymes were effective in cleaning dishes. They found of the eight
phosphate-free detergents tested, six contained enzymes.
Experts suggest that biodegradable detergents may not necessarily mean
phosphate-free. Consumers should check the labels or contact the manufacturers
to determine whether the product is free of phosphates.
For more information on the phosphate content in popular
For information about environmentally-friendly products and
GreenerChoices.org is a source of information on buying products that have
minimal environmental impact.
Phosphorus and the Thames River
background phosphorus concentrations
in the Thames River are
higher than interim
Provincial Water Quality Objectives for phosphorus. Accordingly,
the Thames River is designated as a " Policy 2" river which means that waters
should not be degraded further until all practical measures shall be taken to
upgrade the water quality to the Objectives. This situation is not unique to
London as many other rivers and water bodies in the Province also fall under a
Policy 2 designation for phosphorus.
In recognition of the need to reduce phosphorus loading to the Thames
River, the City of London embarked on a Pollution Control Plant (PCP)
Discharge Strategy to examine water quality in the Thames River system
and set targets for reducing phosphorus concentrations from our PCPs.
With reduced limits, London can still sustain growth while
systematically reducing the quantity of phosphorus that is discharged
from our PCPs to the Thames River. This
report to the Environment and Transportation Committee provides more
information on the PCP Discharge Strategy.