FAIRFIELD — A nighttime storm pounds the grassy, rural hills containing Potrero Hills Landfill and a creature seldom seen emerges from burrows and crevices for a rare journey.
That’s when it’s California tiger salamander time. That’s when the 8-inch-long black salamander with white or yellow stripes travels through dark fields for up to a mile looking for its breeding pond.
“They’ve been co-existing 30 years with the current landfill,” said Jim Dunbar of Potrero Hills Landfill.
But Potrero Hill Landfill wants to expand its active operations into a 215-acre field that contains the salamanders. A five-year quest is under way to remove California tiger salamanders from the field and bring them to another part of the landfill property.
Dunbar on a recent rainy morning drove a van across a muddy, hilly road to reach the trapping area. He had to hike the last quarter-mile because the road became treacherous and he didn’t want the van to slip down an embankment.
The traps are far from elaborate. Dunbar stopped near a small, white bucket buried in the ground with wood over the top. A gap between the wood and the top of the bucket allows a wandering salamander to fall inside.
Biologists with LSA Associates are doing the trapping. They had found no salamanders this particular morning because the rain had arrived after daylight, somewhat later than the previous day’s weather reports predicted. The salamander shuns the daylight for its treks.
Virtually anytime a substantial chance of rain is forecast at night, the biologists come out the next morning. They check 540 buckets containing sponges to keep any trapped salamanders moist.
These traps are designed to catch salamanders, but not other creatures. A string extending from the top to the bottom of the bucket allows beetles and spiders to crawl out and escape. It’s a lifeline for insects and arachnids that does the salamanders no good, given that they can’t climb string.
A plastic-mesh fence around the 215 acres prevents relocated salamanders from returning. Potrero Hills Landfill is creating what is designed to be a new salamander homeland on its property, an area that will remain preserved for the rare creatures, complete with breeding ponds.
Dunbar’s expertise is landfills. He can also recite quite a few facts about the California tiger salamander. That’s because the landfill business and the salamander have become somewhat intertwined for him.
Potrero Hills Landfill has had to address the presence of the California tiger salamander since it proposed expanding the landfill in 2003. At the time, the U.S. Fish and Wildlife Service classified the salamander as a candidate for threatened or endangered status. It has since declared the salamander as endangered.
“The tiger salamander is a cryptic species that spends the majority of its life underground in rodent burrows and cracks in the soil,” the November 2003 draft environmental report for the project said. “Adults are typically observable for only a very short time each year as they move to aquatic breeding sites.”
California tiger salamanders may be rare in general, but not at Potrero Hills Landfill. Researchers found adults in much of the proposed expansion area and salamander larvae in ponds.
All mitigation steps for California tiger salamander loss must take place within the salamander’s known range in southern Solano County, as opposed to another county where the creature is found, the 2003 report said. That southern Solano County range is from Potrero Hills in Suisun Marsh to the Jepson Prairie in the flatlands near Highway 113.
In subsequent years, the California tiger salamander issue came up repeatedly as various federal, state and regional agencies had their say. A major issue was how much land to preserve to make up for the wildlife habitat lost to landfill expansion.
In October 2010, the Bay Conservation and Development Commission issued a permit requiring the landfill to preserve six properties totaling 993 acres for various rare creatures, including the California tiger salamander.
A Solano County Superior Court judge in December 2013 called for BCDC to vacate its permit for the Potrero Hills Landfill expansion because of another issue related to a creek. It remains to be seen how that matter will turn out.
But the salamander hunt goes on as the rainy season continues. This is year two of the effort and Dunbar said more than 200 salamanders have been relocated.
Reach Barry Eberling at 427-6929 or [email protected] Follow him on Twitter at www.twitter.com/beberlingdr.