Low-flow toilets cause stink in San Francisco
Rain drenches San Francisco last month, but it's during summer when sewers emit a rotten-egg smell.
March 1st, 2011
07:21 AM ET

Low-flow toilets cause stink in San Francisco

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 olfactory.

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 report.

So the city is spending $14 million to buy a three-year supply of concentrated bleach to combat the sewer odor, disinfect treated water before it's pumped into San Francisco Bay and sanitize tap water.

The plan is drawing criticism from environmental advocates.

"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 harmlessly."

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Filed under: California • Environment • San Francisco
soundoff (287 Responses)
  1. Philip

    Lowering water flow does not conserve water, it just makes it harder to purify. All of the "inventions" said to conserve water are for one thing: to lower your personal water bill at the expense of the community. Want to really conserve water? Stop flushing food and medications down your drain. Stop washing the grease off your car into the sewer...go to the car wash like everyone else. And remember, it takes about 10 times more water to process red meat than it does to process chicken.

    March 1, 2011 at 10:45 am | Report abuse |
  2. omegarising

    You just have to shake your head at these Governmental morons. So it's going to cost them five times if not more, as much to fix the problem, then what they MIGHT have saved on the 20 million gallons of water. And besides the fact that the bleach will eventually erode the pipes which will lead to MUCH bigger problems and WAY more money. Ahhh, Government brilliance at work.

    March 1, 2011 at 10:46 am | Report abuse |
  3. not surprised

    Uuuuh why dont they just turn the pressure back up a little ????

    March 1, 2011 at 10:59 am | Report abuse |
  4. tm1946

    Got to love the left wing loonies. With the best of intentions, they continue to outthink themselves. Got to feel warm and fuzzy about themselves and create problems no one considered. HAHAHA, quite humorous. Maybe they could get some of the illegals hiding there for a common sense solution.

    March 1, 2011 at 11:01 am | Report abuse |
  5. Add Up

    Wait – it's saving 20 million gallons of water per year – that's 60 million in three years, but it's gonna cost $14 million to fix problems caused by this "water saving" over three years?

    That's about a quarter per gallon of water "saved".

    That's expensive water.

    March 1, 2011 at 11:10 am | Report abuse |
  6. scieng

    Most of the major cities in the world have this problem. I worked on it for over 10 years, and came up with numerous treatments (and patents)–some used in other CA towns. This is not just one problem–but several. All are created by increasing the solid compared to the liquid flows. You can save water with reduced flushing, but increase the cost of treatment. In the end the systems require a lot of non-toilet direct flushing from water mains. The water savings is very small, but the health and environmental risks are very large. The utlimate answer is to limit the number of people to the amount of available potable water in that area. And no, sea water flushing destroys the waste water treatment system. Bleach will also damage or destroy the wastewater system.

    March 1, 2011 at 11:11 am | Report abuse |
    • DB

      Ding, ding, we have a winner.

      March 1, 2011 at 9:47 pm | Report abuse |
  7. buccakenji

    Pelosi is living in the sewers now????

    March 1, 2011 at 11:15 am | Report abuse |
  8. Dan

    ughhhhh. Not San Francisco whining and crying again about some minuscule issue. You wanted to save the earth with your crappy crappers; live with the consequences and leave the rest of us alone.

    March 1, 2011 at 11:24 am | Report abuse |
  9. Don G

    I have been a property manager for over 35 years. Blaming low flow toilets for the smell is the biggest bunch of BS I have ever heard, and here is why. First, if there is enough water to clear the bowl then there is plenty of water to keep it moving along once it reaches the sewer mains. If low flow was to blame for the build up then the lines within the homes and other buildings would also have a build up and stop working. Second, toilet water is only a fraction of the water running through the sewer mains, there are still the showers, sinks, washing machines, restaurant kitchen use, industruial use, etc. Thirdly, if you ever saw inside a sewer main you would see that most of the time the pipes are only 1/3rd full as the water and solids pass through. The deposits on the sides and top of the pipe happen when there is higher than normal flow or a clog occurs. Who the heck do they think they are kidding? The problem is almost certainly related to the fact that the old cast iron pipes naturally catch and hold the solids. The odor which has to be coming from the vented man hole covers is most likely due to the fact that the pipes have narrowed and during high flow periods, IE first thing in the morning, the water and solids back up and start filling the man hole. When the flow reduces, the man hole concrete sides are covered in the sludge. That is what is causing the odor. So rather than admit that a lot of the infrastructure needs to be either replaced or mechanically cleaned they are going to take the cheep method of blaming low flow toilets so they can dump chemicals into the system. Ineffective and a waste of money!!

    March 1, 2011 at 11:25 am | Report abuse |
  10. mike

    20 million gallons a year savings is only abour 2.5 gallons per person per year. This is a drop in the bucket, really. Why all the cost to change toilets (even gradually, as remodels occur) and the unintended consequences as in this article for such small savings, yet the use of water by agriculture wastes a lot more.
    Besides, how does the city even know how much was saved? Does it measure the number of flushes? NO! It is fiddling with gross measurements and making unsubstantiated assumptions to try to prove that there is a savings. More would be saved just by helping people learn to fix leaks and turn off the water when you brush your teeth.

    March 1, 2011 at 11:28 am | Report abuse |
  11. fuyuko

    I hate the low flush toilets. what is the point if you have to flush multiple times to get a flush you used to get in one shot. Why not simply use gray water instead of forcing everyone to use toilets that cause a stink and don't work as well?

    March 1, 2011 at 11:32 am | Report abuse |
  12. Ceng

    The rotten egg smell is caused by bacteria that break down the sewage, pouring bleach on it will not solve the problem, which is the low flow situation. Maintenance needs to get out there with a Vac truck and flush the sewer lines, that's what manhoels and cleanouts are for. A utility as big as San Francisco should know better.

    March 1, 2011 at 11:34 am | Report abuse |
  13. not surprised

    If its yellow let it mellow if its brown flush it down

    March 1, 2011 at 11:34 am | Report abuse |
  14. Bubbashrimp2

    Good for them! SF is the pig stye of liberalism and Nancy Pelosi and her friends should wallow in the world they have created. The summer of sludge has replaced the Summer of Love. Quick, send John Cafferty to cover that story, send him down in a spilunking outfit to determine the real cause....The goverment can't even flush a toilet correctly. And you want socialized goverment controled Health Care? Try to see how that plunges us into the sewer of their corruption!

    March 1, 2011 at 11:35 am | Report abuse |
    • Mars Bonfire

      Crap... does this mean there's a bubbashrimp1 running loose out there somewhere?

      March 1, 2011 at 1:11 pm | Report abuse |
  15. major

    more fiber less ricearoni

    March 1, 2011 at 11:37 am | Report abuse |
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