While the Regional Water Quality Control Board is trying to make a clean sweep of West Marin's Stemple Creek, further upstream Sonoma County public works officials have proposed expanding the county's central landfill - near the creek's headwaters at Button Ranch.

The Two Rock ranch has several streams that converge to become Stemple Creek, which flows into the Estero de San Antonio and enters the ocean above Dillon Beach. These interlinked waterways span 50 miles of agricultural land in West Marin and Sonoma counties.

Stemple Creek has been contaminated by erosion, run-off from the watershed's dairy and livestock ranches, and leachate discharged from the Sonoma landfill in 1995, according to water board records.

Required by the Clean Water Act to target pollution in the state's watersheds, the water board now aims to clean up the creek by the year 2004.

Sonoma's Central landfill on Mecham Road lies near the eastern border of Button Ranch. As the county's sole municipal dump, the landfill accepts about 430,000 tons of garbage every year. Although Sonoma residents are recycling "responsibly," the dump is nearly full, said Integrated Waste Manager Ken Wells of the public works department.

In order to avoid a "crisis," public works staff wants to expand the existing 390-acre dump by carving out portions of county property to the west and to the east, stretching the landfill's use until the year 2014.

By that time, a new dump site should be selected and ready for use, Wells said.

In addition, Wells' agency wants to acquire about 10 acres of private ranchland to be used for "operational improvements" including a hazardous-waste collection facility and a public recycle/reuse area.

The additional 10 acres would be carved from the Summit C Dairy near the proposed eastern expansion - a maneuver which would "destroy" the dairy, said owner Eugene Camozzi.

"They want to expand the dump to about 200 feet behind our hay barn. Hazardous waste would be put along our fence line," Camozzi complained, adding that he didn't want his Holsteins nearer to debris.

"We've been pretty good neighbors to the dump, and we knew it was next door when we moved here six years ago. We just didn't expect this expansion," the dairyman said. "We really don't want to sell our land to the county."

Wells argues that the proposed project would solve a countywide disposal problem, and would improve the way people sort, recycle, and discard their trash.

"Of course, no one wants a dump in their backyard," he added, "but unfortunately, we all make garbage."

Kathy Tresch, co-owner of Button Ranch, says she's tired of the junk beyond her backyard. A ridge now hides the landfill from view, but she says that may change should dump spread west.

"They're going to scoop out the ridge, and we'll see the garbage and hear more noise," Tresch told The Light. As she spoke, dump trucks beeped in the distance.

Tresch objects that her land was placed "on the county list" as a possible landfill site in 1988, and since 1991, as a possible site for a city of Santa Rosa sewage reservoir.

Although The Geysers north of Healdsburg has now been chosen for a sewage facility, Tresch worries that her land has been permanently tagged for trash.

Plans for the county's future dump site are now sketchy, but four sites are being considered by public works officials - and one with "potential" is Button Ranch, Wells said.

"Clearly, it's located in a beautiful valley. But since it's secluded and nice, the ranch would make for a great landfill," he explained. "It's close to the existing facility, and relatively close to population centers where garbage is generated."

Setting aside her worries about the future landfill site, Tresch is wary of "the garbage spread" close to home. She wonders how it may affect the marshy headwaters of Stemple Creek on her land, and the groundwater below.

She also fears the swelling landfill may weaken the health of the cattle that are her livelihood.

Kathy and husband Joe Tresch run an organic dairy ranch - the second to be certified in the state after the Straus Dairy in Marshall. To become certified last year, the Treschs had to prove that their land was toxin-free and that their herd was healthy.

"If the dump expands, the health of our organic herd could be affected, and we're limited in the ways we can respond to illness," Kathy Tresch said. "We don't have an arsenal of antibiotics at our disposal. We have to use homoeopathic remedies and aspirin."

The Tresches also milk 600 commercial Holsteins, continuing a near century-old family tradition. Their 320-acre "home ranch" was established in 1905 by Robert Tresch, a Swiss-Italian immigrant from the Ticino region.

Last year, the Tresches expanded their ranch by buying the bordering 1100-acre Button Ranch from the Regents of the University of California.

Kathy Tresch noted with irony that when Ray Button first acquired the property in the 1960s, he gave neighboring ranchers a copy of Rachel Carson's Silent Spring , an early warning of toxic hazards and pollution.

"Mr. Button took really good care of the springs on this ranch while he was alive. He only made a couple of mistakes," Tresch said.

Dennis Salisbury, the Regional Water Board engineer overseeing the cleanup of Stemple Creek, agreed that dumping garbage nearer to springwater might be a big mistake.

"There may be other, better sites for the landfill expansion. Button Ranch has got a lot of groundwater resources and springs, and it may have some seismic faults," Salisbury explained.

"I don't care how good a landfill is, it can have problems," he added, citing the leachate and sediment "flushed" into Stemple Creek from the existent dump during the storms of 1995.

Salisbury called the Tresches "model stewards" because of their careful erosion management and their "innovative" manure-spreading technique.

"They've got a pretty healthy ecosystem there," he said. " The only thing missing are black bears, which used to roam around those hills for hundreds of years."

Kathy Tresch refers to her ranch as a "nature preserve." She says her land serves as a habitat for 500 plant species, Northwestern pond turtles, steelhead trout, blue-tailed skink lizards - and a pair of breeding golden eagles.

Landfill expansions tend to "eat up" valuable habitat, noted Fish and Game environmental specialist Mike Rugg, who regretted that his agency "rarely" affects public-works department decisions.

"We can only hope that any expansion of the dump would be regulated by the water board to a degree that would improve the situation," Rugg said.

Nevertheless, the garbage will mount. Tresch fears that scavenger seagulls - "vectors for disease" - will follow the litter to her land.

In addition, she worries about the archeological value of her property. Four Miwok Indian sites are known to exist there, she noted, adding that she's discovered a number of mortars and pestles.

"Sometimes I find things on the ground while I'm walking the cows out to pasture after heavy rains. My daughter once found a perfectly-formed spearhead made of obsidian."

After hiking around the hills and streambeds of Button Ranch, waste manager Wells told The Light that the land had "significant biological diversity and several kinds of resources."

Yet, he added, "I have to divorce myself from my emotional feelings about that place in order to be a good waste manager."

The deadline for public comment on the Sonoma County landfill-expansion proposal ends Nov. 20. Comments should be addressed to: Tim Mayer, Sonoma County Permit and Resource Management Department, 2550 Ventura Ave., Santa Rosa 95403.

Copies of the county's environmental-impact report can be viewed at Sonoma County regional libraries in Petaluma, Rohnert Park, Sebastopol, Santa Rosa, and Sonoma.