Today D. and I visited the Las Gallinas Sanitary District Wildlife Area in San Rafael (Marin County, north of SF). Although the name of the place doesn't sound very appealing ("Sanitary District"??), waste water treatment plants often provide birdwatchers with excellent opportunities to see marshland species from levee trails encircling their oxidation ponds. These are the ponds where microorganisms (such as aerobic and anaerobic bacteria and algae) biodegrade the organic nutrients present in the wastewater. The Las Gallinas plant has 5 such freshwater and saltwater ponds alongside nearby tidal marshes, creating an exceptional bird habitat. Numerous waterfowl and an array of raptors as well as songbirds can be seen there.
Today we saw huge flocks of white pelicans; great and snowy egrets; killdeers; stilts; avocets; mallards; Canada geese; barn swallows; a mockingbird; crows; cormorants; starlings; Savanah sparrows; goldfinches; a falcon too far away for me to identify; an immature black-crowned night heron (but no sign of mom or dad); what was probably an immature green heron (why can't these birds sit still long enough for us to get a good look at them?!); lots of turkey vultures circling the thermals overhead for endless stretches without flapping their wings; and a great blue heron.
Behind one pond we were startled to see a huge array of solar panels. They're used to power the pumping equipment for the various ponds at the treatment plant. (The plant also gets some power during the primary stage of waste treatment: the methane gas produced by the enclosed anaerobic digesters is used in an engine generator to produce electricity, and the waste heat from this cogeneration is recovered to heat the digester.)
It was a nice chance to get out of the foggy city and into some sunshine and toasty temperatures and observe wild creatures living their lives in peace.