The city of San Francisco’s push
for low-flow toilets is saving water –
at a smelly price.
Use of the low-flow toilets has cut
city water consumption by 20 million gallons a year, Public Utilities
Commission spokesman Tyrone Jue told the San Francisco Chronicle.
But the cost is both monetary and
Because water flow isn’t pushing
the waste through the system fast enough, a stinky sludge is building up in the
sewers, the Chronicle reports.
It’s blamed for a rotten-egg smell
wafting through areas of the city, especially during summer, according to the
So the city is spending $14 million
to buy a three-year supply of concentrated bleach to combat the sewer odour,
disinfect treated water before it’s pumped into San Francisco Bay and sanitize
The plan is drawing criticism from
“Using sodium hypochlorite,
commonly known as bleach, is the equivalent of using a sledgehammer to crack an
egg; it’s the wrong tool, and it will cause irreversible collateral
damage,” San Francisco chemical engineer Adam Lowry and German chemist
Michael Braungart wrote in a Chronicle op-ed.
Their solution to the stink: either
dumping hydrogen peroxide into the sewers or “a pro-biotic solution, that
is, enzymes or bacteria that would simply ‘eat’ the smell then degrade