Frank J. Horgan Filtration Plant

The Frank J. Horgan Filtration Plant is located Southeast of Toronto on
the shores of Lake Ontario (See map). Its purpose is to provide safe drinking
water to our taps by filtering the water. The water is gathered from Lake
Ontario. This plant has a production capacity of 455 million litres per day to
supply the residents of Toronto with drinking water. Its average production of
drinking water is 355 million litres per day. It is also the newest filtration
plant in Toronto.

The Frank J. horgan Filtration Plant was built from 1974 to 1979 on
property acquired from the city of Scarborough, It opened on May 22,1980. When
it opened, it was not named Frank J. Horgan Filtration Plant but was names
Easterly Filtration Plant. This was because the plant was on the eastern side of
Toronto. The name seemed appropriate at the time. The name was changed to Frank
J. Horgan Filtration Plant at 1990 by the commissioner of works for Metro
Toronto. This plant cost about 57 million dollars to construct. About nineteen
major contractors worked on this plant and were supervised by the Engineering
firm of James F. Macharen Limited. Although it is the newest plant, it had it’s
disasters. Their intake value exploded twice between 1980 and 1995 because of
the extreme pressure and Wight of the water. these incidents cause a shutdown of
the plant until they could repair it.


The Frank J. Horgan Filtration Plant needs only one row materials to
operate, which is water. The plant is right next to lake Ontario, collecting
water to purify. The water enters the plant by means of two 114 and four 182
million litres per day pumps, sum 18 meters below sea level and 2960 meters off
the shore. Since the pressure of the water at that depth is so strong, there is
no need for any mechanical pumps. They just let pressure and suction to do the
job. The water is now treated with chemicals which are aluminium sulphate (alum),
lime and chlorine. Alum is used to stick dirt particles together, to make large
clumps of dirty called "floc". A lot of chlorine is added to the water to kill
the bacteria. If we were to drink it, you would die from chlorine poisoning. The
Chlorine, by the end of the filtration, drops to a safe level. This is where the
alum does its work. Coagulation is basically mixing the alum with the water.
This is a achieved by high speed in-line mechanical blenders. Flocculation
occurs right afterwards. Alum could be either poly-aluminium chloride or
aluminium sulphate, is a very sticky substance which likes clinging onto dirt
particles. All this flocculation is done in three stages:

1.Focculation is achieved by exail flow turbines with varied inputs of energy
and the last two stages are done in two 900mm diameter pipelines.

2.The next step in filtering the water is filtration. The water passes through 8
dual media filters. This is where some bacteria and the floc are removed. The
filters consists of the following in order: 0.305m of grated gravel, 0.35m of
sand and 0.460m of anthracite. This was the best composition for the filter to
make it effective. Normally this would be done once but if the water is really
dirty it would have to be filtered again to meet the government standard. By now
most of the chlorine in the water has killed most of the bacteria and the level
of chlorine in the water is much lower.

3.Here is where they kill any remaining bacteria and add flavouring to the water.
They add about 1.2mg per litre of chlorine, any more and it will kill you from
fluorine poisoning. Chlorine is also added to kill any remaining bacteria. This
time if you drink the water it is safe. If there are high levels of bacteria
they would have to go through a process called "Super-chlorination". Hence the
name, they increase the chlorine dosage. After that, they reduce the chlorine
content by adding sulphur-dioxide. Ammonium is added to the water.

The final stage is storage and distribution. By the time the water gets to your
home there may not be any chlorine left. This is not good because what if there
was bacteria in the pipes? The ammonia prevents the chlorine from evaporating
that easily that way it is killing any bacteria in the pipes. All water you
receive from your taps is a combination of all four filtration plants in Toronto.

Waste Disposal

Most of the waste produced in the filtration plant is in the dirty