Steps Towards Sustainable Agriculture, Summer 2005

Straus Family Creamery

Bill and Ellen Straus started dairy farming in 1941 near Marshall, next to Tomales Bay in western Marin County. Today, three of their children are still involved in what is now the Straus Family Creamery, run by son Albert Straus. The operation has 280 dairy cows that are grazed and milked on a 660-acre site, about a third of which is devoted to raising feed crops, including oats, rye grass, and vetch. The creamery facility is located on a half-acre nearby site.

Raised a conventional farmer, Straus has a degree in Dairy Science from Cal Poly. In the 1990s someone asked him about organic milk for ice cream, an idea he kept in the back of his mind. Straus revisited the organic idea again and in 1993, he and his parents converted the dairy to organic production. Theirs was the first certified organic dairy west of the Mississippi.

Straus also buys organic milk from the neighboring Tresch and Mattos family dairies. The three dairies have a combined total of 1,450 cows that produce an average of 10,000 gallons of milk a day. Milk production naturally fluctuates and the cows produce more in the summer and somewhat less in the winter. Most of the milk is bottled or made into butter, yogurt, or ice cream at the Straus facility. Excess is currently sold to other companies, including a company that makes organic cheese. Currently Straus sells about 70 percent of their products in the local region and are working to expand their markets so that they can sell 100 percent locally. Most of the rest is sold in California; some is also sold out of state.

California has about 1,950 dairies, with nearly 2 million cows producing 11 millions gallons of milk a day. Of these dairies, approximately 30 are producing organic milk. As is standard practice in both organic and non-organic dairies, male calves and cows removed from the herd, are sold for meat. Although their calves and cows are sold at auction in nearby Petaluma for human consumption, Straus noted than none of the calves are used for veal.

Energy Conservation

Straus’ energy use includes power to operate on-site equipment, including refrigeration, milking equipment, water pumps, slurry pump, milling equipment, grain grinder, and aerators. The dairy also uses fuel to operate on-and off-site farming equipment and transportation vehicles (delivery trucks, vehicles to transport employees on and between sites and to and from work.)

In 2000, through grants from the State Energy Commission and the State Water Resources Control Board, Straus was able to start construction on a methane digester. The digester turns cow manure into electricity, reducing air and water pollution along the way.   According to the Wallace Group, which built the digester, cow manure will produce approximately 44 cubic feel of biogas per day per cow, which is about 60 percent methane. All of that can be captured by the digester. Methane is a greenhouse gas, 21 times more potent than carbon dioxide gas.

Since April 2004, when the digester was completed, Straus has been able to meet 85 percent of its equipment energy needs related to milking and feeding the cows. Currently 14 other dairies in California have methane digesters that are producing electricity. All of these were constructed with some grant funds.

The digester process starts with manure being flushed out of the dairy stalls and downhill to a slurry separator that divides solids and liquids. The solids are trucked to an on-site area where they are composted and then spread on the fields. The liquids are collected in a holding pond and then pumped into the anaerobic digester, the first in a series of four unlined earthen ponds. According to the Wallace Group, although the ponds are unlined, the groundwater will not be contaminated because the bacteria create a membrane on the pond bottom that becomes impermeable to water over time.

The 9000 square-foot digester pond is covered with a 60-mil-thick plastic floating cover which is weighted at the edges so that it stays under the liquid, forming a sealed space into which the methane gas collects as it escapes from the liquid. The methane gas that is produced by the digester is suctioned into the nearby 75 KW generator. The generator runs 14–15 hours a day, sending electricity into PG&E’s grid. Both the generator’s output and Straus’ electricity use are metered and Straus is credited with the difference. There is a lag in payment, however, so Straus doesn’t get the economic benefits immediately. Overall, Straus’ monthly electric cost has been reduced from $4,000 to $600.

The water gets pumped from the second pond to a series of two more ponds that allow for more solids to settle out for ongoing biological digestion to clean the water. Water from the third pond is used to flush the stalls. Water from the fourth and final pond, which is the cleanest, is used to irrigate the pasture.

In addition to producing electricity, the generator also heats about 5,000 gallons of water per day that is used to wash out the stalls. The generator has also cut in half the site’s use of propane used to heat the water.

Digester designer Edwin Lee explained that digesters of this type are economically feasible because the ponds are constructed with low-cost earthen materials rather than with expensive concrete.  With government assistance, the typical payback for the initial investment is about 15 years.  However, ongoing maintenance of the digester will be required.  The cover will last about 15 years, after which time it could be potentially be recycled or will be landfilled.  At some future point, solids which have collected in the digester pond will have to be removed.

They have a solar-powered bug zapper, notes Straus, but do not plan any large scale solar power system because of the high cost. They have also experimented with a small-scale wind power system to pump water, but its capacity has been limited.

Vehicles and Transportation

Straus has five tractors and five trucks at the farm and four trucks at the creamery, all of which run on conventional diesel. Straus has not yet tried biodiesel; he has started to look at the possibility of using vegetable oil for fuel. He uses an electric car for work and personal use; the car is charged from the electricity produced from the methane generator.

Currently Straus produces about half of the cows’ food on site. He gets about a quarter of the feed from California and imports about a quarter from the Midwest.

Straus explained that when they converted to an organic dairy, they had to also feed the cows organically certified foods. “I went to the yellow pages and started looking for organic feeds. We’ve tried the organic soybean pulp (left over from tofu production), and cocoa beans. We now feed them organic rice grain from the Central Valley but still have to import from out of state.” Since becoming organic, their feed costs have gone up about 50 percent.

Finding feed sources was an issue even before they became organic. Straus describes how they once tried feeding the cows Saki residue from the plant in neighboring Napa County. “We ended up with a few drunk cows one night and we spent the night having to roll them from side to side so they wouldn’t stop breathing.”

Land and Habitat Preservation

Bill and Ellen Straus were both active in trying to preserve agricultural and open space in Marin County. As Albert explains, “My father helped found the Tomales Bay Association, an environmental group. He was very active in keeping communication between the environmentalist and the farmers. In the 1970s there were plans to develop the east side of Tomales Bay, to have 150,000 people living here and a freeway running along the bay. My parents were one of a few farming families that wanted to keep the land for agriculture.”

His parents’ effort included working to help pass a county ordinance that restricted development to one house per 60 acres. Although it passed, Ellen Straus was concerned that the Board of Supervisors might eventually overturn the ordinance, so something more permanent was necessary. In1980, she and a friend, biologist Phyllis Faber, founded the Marin Agricultural Land Trust (MALT). Farmers sell MALT their development rights and a conservation easement is recorded on their land. The easement runs with the deed so that the land cannot be developed by successive owners. To date, 50 farms and other landowners have sold MALT the development rights to more than 35,000 acres.

Their farming practices support natural habitat, Albert noted. “We have fenced off the creeks to keep the cows out and planted willows to help clean the water. We don’t allow guns or hunting on the property, so we have lots of wildlife, animals and birds.”

Water

Water quality is always a concern in any watershed, explains Straus. Dairies in California use about 25-50 gallons of fresh water per cow per year for dinking; water is also generally used to irrigate feed crops. At Straus, while they don’t irrigate the pasture or cultivated crops, Straus explained, they do put water from the digester ponds on the pasture as fertilizer. About 2,400 gallons of fresh water are used per day to flush the milking parlor and about 10,000 gallons of recycled water are used per day to wash out the freestall barns (in which the animals are not tied up).The fresh water comes from a shallow underground aquifer and the recycled water comes from the ponds as discussed above.

Water from dairies enters the surrounding watershed through surface runoff and by filtering through the soil into the water table. Currently, testing of agricultural water discharge in California is not required as it would be for factory, sewer, or other types of commercial or institutional discharge.

Water from the Straus and neighboring dairies, which are uphill of adjacent Tomales Bay, runs into the bay. Straus noted that a 1996 study of fecal coliform in Tomales Bay (conducted during the rainy season) showed that the bay was impaired by unacceptably high levels of fecal matter. Although the study did not specify the cause, Straus explained that better tests are now available to determine the pollution source. In 2003, two people got sick eating oysters from Tomales Bay. “There were voluntary efforts on the part of farmers to reduce runoff and potential pollutants in the runoff, but the standard was set too high. It is not realistic to assume that you can eat oysters out of the bay 365 days a year.”

Because Straus is a certified organic dairy, they cannot use hormones, antibiotics, pesticides or herbicides that could potentially contaminate surface- or groundwater cannot be used in production. Straus explained that one of the challenges of becoming organically certified was treating the cows without antibiotics. Albert had heard about homeopathy and took a class at Covelo Organic Vegetables, a community support agricultural farm in Mendocino County. “It was a little hard to see getting a cow to take a pill three times a day, but then we figured out how to inject it under the skin. We also used aspirin for certain things. Really it is about prevention, keep bedding clean and dry. You have to stay on top of illnesses and get things taken care of right away. Now, my herd’s health has never been better.”

One measure to prevent hoof and mouth disease is the shoe bath outside the gates. People step into a sanitizing solution to sterilize any bacteria before they come in. Straus also breeds all replacement animals from their own herd, which helps reduce the chance of disease that outside animals could bring.

Flies are an ongoing problem, he noted. They have tried fly strips and now have solar bug zappers which have eliminated most of the flies.

Soil Conservation

Loss of topsoil through cultivation practices is an important concern in commercial farming. Two ways to address this are through tilling practices and the use of compost. Of the 200 acres which Straus uses to raise feed crops, about 50 are planted using no-till methods and they use minimum tillage on the rest. The no-till planting is accomplished by the use of a drill seeder that cuts a small hole in the topsoil and plants and covers the seeds. No-till or minimum tillage practices also require less tractor usage, thus reducing fuel consumption.

Straus also adds compost to both the cultivated fields and the pasture made from the digester solids. Feedstock for the compost includes the solids from the digester slurry and manure and rice hulls that are cleaned out of the free stalls.

Waste Reduction

Straus generates potential waste at both the farm and creamery sites. Like most farm operations, potential waste includes non-working equipment, plastic bags, used tires, and employee food waste. Of this material, very little is going to the landfill. Non-working equipment is salvaged for parts, and leftover metal is taken to Global Recycling in southern Marin County for recycling. Waste tires are used to hold down covers on the silage piles. Film plastics are landfilled.

At the creamery location, areas of potential waste include a total of 77 tons of unsaleable product, packaging, and assorted lunch and office waste. The Straus Dairy has received several awards from the CIWMB Waste Reduction Award Program for reducing this waste. Products with short expiration dates are donated to local schools, and other unmarketable products are available to employees. Any remaining organics are trucked to the other site and put into the methane digester. Nearly two-thirds of the packaging waste, including glass, plastic bottles, and cardboard is recycled; the remaining approximately 7 tons is landfilled.

About 25 percent of Straus milk is sold in reusable glass bottles. A $1.25 deposit is charged on the glass bottles and the bottles are used between four and seven times year, notes Straus. Straus estimates that the glass in the bottles is 45-50 percent recycled content. The milk is transported in reuse able plastic crates that carry a deposit to ensure that they are returned.

Their ice cream and butter are packaged in coated paper which is not recyclable but can be composted. The cardboard boxes used to ship yogurt and butter range from 70-100 percent postconsumer content, notes Straus.

Straus previously used #2 colored plastic tubs for the yogurt. However, Straus noted, when they learned these were not recyclable, so they switched to #5 plastic because it is lighter and uses less plastic. They are on the lookout for a compostable package and considered using packaging made from cornstarch. But cornstarch packaging currently uses genetically modified organism (GMO) corn, which is not acceptable in the organic industry.

Another way the Straus Dairy reduces waste is to use much of the same milking and creamery equipment that has functioned since the 1950s and ‘60s. But keeping the equipment running requires three full-time mechanics, and getting spare parts can be a problem.

Other recycled products that Straus uses have included animal bedding made from shredded government documents from Mare Island. They now use rice hulls from the central valley and wood shavings from the north coast.

Contact Information:

Albert Straus
Straus Family Creamery
PO 768
Marshall, CA 94940
415-663-5464
Fax 415-663-5465
family@strausmilk.com
www.strausmilk.com

Last updated: August 01, 2008