The San Francisco Ecological Intelligence Pop Quiz

Lisa Van Cleef / SF Chronicle 10jan01

1. Where does your trash go?

"Out to the curb" is not the right answer. Trash is picked up by either Golden Gate Disposal if you live downtown or by Sunset Scavenger if you live in any other San Francisco neighborhood. Then it's all taken to the Solid Waste Transfer Station on the southern edge of town across the freeway from Candlestick Park.

It's then loaded onto trucks, which take the garbage to the Altamont Landfill, east of Livermore. These trucks make approximately 110 trips a day to dispose of the whopping 8 million tons of trash San Franciscans throw away every year.

Now, some folks are under the misconception that kitchen and yard waste will decompose in a landfill. Not true. The landfill is packed so tightly that the necessary water or oxygen never reach the trash, which means decomposition cannot occur.

Tragically, a whole lot of that garbage doesn't need to be there. It is estimated that 30 to 50 percent of everything that ends up in the landfill can actually be composted. By doing so, organic gardeners and their compost bins help to divert valuable compost material from a hogging land and becoming mummified in the landfill.

2. Where do the contents of your toilet go when you flush?

Into the sewer line that is typically buried five feet below your front sidewalk. Our storm drains empty into this system, as well. Gravity hustles the sewage off to our two main treatment stations -- Oceanside, near the zoo, and the Southeast plant in Hunters Point.

Wastewater and solid matter are separated and undergo a series of purification treatments. The solid matter eventually ends up in the landfill (see question 1) and the wastewater is dumped directly into the ocean at the Oceanside plant and into the bay over at the Southeast plant.

According to Beverly Hennessey of the San Francisco Public Utilities Commission, people who use our storm drains to dispose of used motor oil, paint, herbicides or pesticides, and those who pour grease, coffee grounds and oily foods down their sinks or garbage disposals are directly affecting the quality of our water.

Even a state-of-the-art treatment plant can't eliminate all of the crud from our wastewater. The SFPUC proudly touts the fact that the wastewater is 95 percent pure before it's dumped into the ocean. But it still leaves that other 5 percent floating in the bay.

Each of us -- corporations included -- has a direct impact on the health and cleanliness of our bay and ocean. Anything we toss down the sink may eventually make its way there. This hits closer to home, too when you realize that ocean water evaporates and becomes rain and snow, which collects in our reservoirs and is eventually returned to us as drinking water.

3. Where does your tap water come from?

Anyone watering a garden will have this question wander by at least once. If you've lived in California for any length of time, you're aware that water is a rare, precious resource. It does not come gushing out of your hose like magic. In fact, our water actually travels 167 miles to get here.

Eighty-five percent of our tap water comes from the Hetch Hetchy Water and Power system. The snow melt from Yosemite National Park and the Stanislaus National Forest is collected and sent by gravity through a series of pipelines and tunnels to San Francisco. The other 15 percent comes from reservoirs in Alameda and San Mateo counties. (It has been said that John Muir died of a broken heart when the Hetch Hetchy Valley was dammed, a move he vigorously opposed.)

Because the water is so pure and is transported through enclosed pipes, our system is one of only four systems nationwide that does not filter its water (unless it's been stored in one of the open reservoirs). Chlorine is added at plants in Alameda and Palo Alto. The systems serves 2.4 million people in Alameda, San Francisco, San Mateo and Santa Clara counties.

BONUS QUESTION (This is not about your ecological intelligence. It's just interesting.)

What is the most reliable economic indicator that sits on your curb?

A. Your trash. According to Robert Reed, spokesman for Norcal Waste Systems Inc., the parent company of both Golden Gate and Sunset, trash is a key indicator of economic health. Reed says the volume of garbage always goes up when times are flush, and bottoms out when times are tough.

Last December, San Franciscans tossed out 65,123 tons of trash. This December, we disposed of a cautious 62,114 tons. In fact, we disposed of more garbage in November, 63,518 tons, than in December.

That fact is more disconcerting than it appears, because trash volume can and often does increase by up to 2,000 tons in December, due to all the garbage the holidays generate. For the landfill, our reduced trash is great news. Economically, it is not a good portend.