462 Preventing and Reducing Harm from Toxics
A taste of clean production
The beautiful views from the hills of San Francisco, USA, attract tourists
from around the world. So does the variety of foods served by its many small
restaurants. But with so many restaurants, waste oil from cooking became a
problem, clogging sewers and costing the city money. The city requires that
all restaurants use a “grease trap” to prevent oil from entering the sewers, but
emptying and cleaning grease traps is expensive. Many small businesses owned
by recent immigrants cannot afford it.
San Francisco’s Public Utilities Commission, in charge of the city’s sewers,
decided that instead of charging large fines to restaurants for not disposing of
their oil properly, they would offer a solution. They would collect the waste oil
and use it to run city buses!
When the diesel engine was invented, it burned light fuels such as vegetable
oil. But because petroleum was cheap and plentiful, and the companies that
produced it were powerful, most diesel engines began to use petroleum. Now,
with the serious pollution and global warming caused by petroleum, people are
returning to vegetable oil as a cleaner and less costly fuel.
Vegetable oil can be used after making a few changes to a diesel engine,
or the oil can be turned into “biodiesel,” which can be used with no changes.
Burning biodiesel dramatically reduces the air pollution that causes asthma
and cancer, and it does not cause global warming. Compared to other fuels,
such as natural gas, it is also less expensive.
Making biofuels by recycling waste oil is different than growing a new crop
just for fuel. It keeps a waste product out of the sewers and puts it to use.
To make clean production work, the San Francisco Public Utilities
Commission hired native speakers of many languages to visit restaurants and
collect waste oil. The restaurant owners
no longer pay to get rid of their oil,
and the city benefits by
having fewer clogged
sewers and cheaper
fuel for its buses.
Now, instead of
smelling like traffic, the
streets of San Francisco
smell like fried food.
Which brings more
tourists than ever to
local restaurants.
A Community Guide to Environmental Health 2012