We saw many signs on Interstate 5 on the way to Lodi saying “Congress created a Dustbowl” because of recent legislation which limits the amount of water that can be drawn from the Sacramento River for irrigation. To me, the farmers knew that they were not going to be able to pull water out of the Sacramento forever. They shouldn’t be so surprised that unsustainable farming practices will be banned eventually. Norris pointed out that CA congress should not suddenly impose new rules on farmers. Sure, current practices may not be sustainable, but there needs to be a transition period for farmers to adapt. So there are two of the arguments. I am sure there are plenty of others.
There was also a sign that read: “Toilet to your tap! Why can Sacramento & Stockton Daily Dump 200 Million Gallons of Sewage into the S.F. Bay-Delta? Killing Fish & Polluting the Drinking Water for 25 Million People Downstream!” This seems to be part of the land applied biosolids question we have been looking so much at the last couple of weeks.
Castelanelli Brothers Dairy was the first time we saw a lagoon digester. This is the cheapest kind of digester and the only kind which Kurt Roos at the EPA thought would be appropriate for Nigeria. I was interested to see how it works.
This digester was operated by Larry Castelanelli. He has 2 acres of lagoon digester. The lagoon is covered with black plastic to catch the methane. Larry decided to use one gauge thicker plastic than was recommended just to be safe. He said it was fine to walk on and we did. The bottom of the lagoon is just dirt. “Is it filling up with solids on the bottom? I don’t know,” said Larry. To cover the two acres cost $220,000 in 2003. In 2003 Larry spent $800,000 overall on the project and recently he spent about $400,000 to upgrade the generator and install a biogas scrubber. The lagoon is not heated and the only stirring is caused by a 6 foot agitator. The manure comes from 3,000 cows.
At the Fiscalini Cheese Farm, John had mentioned that his anaerobic digester system was the only one that would work on a flush dairy. This was also a flush dairy yet used a very different digester system. Larry suspected John’s water table may have been too high to install a lagoon digester.
Here is one of the flush lanes.
This is the screen separator. One of the important (and different) processes in Lagoon digesters is to remove solids from the effluent so that it does not accumulate at the bottom of the lagoon. Whereas at Fiscalini the solids were removed and applied to the digester, here, the solids where removed and left in a pile to be hauled away while the liquid was used in the anaerobic digester. This has me confused as to which part of the manure should be used for digestion, but perhaps the answer is both. Both the liquid and solids have energy for digestion.
A Guascor Generator rated at 300kW (I believe) was used to turn the biogas into electricity. Larry previously had a 180kW generator which was enough to power the whole farm. At the time, his contract with the electric company said his excess power was given to the electric company for no charge. Under a new contract he makes $0.10 per kWh sent to the grid. Because his original grant application in 2003 stated that he planned to install 300kW of capacity, he did not have to deal with any extra red tape that John at Fiscalini Cheese Farm experienced.
The gas is now scrubbed using a biologically active screen. Probably a biotrickling filter as RCM installed Larry’s digester and that seems to be their scrubber of choice.
The screen shows the operating status of the digester. Here was the first time we saw a farmer use his iPhone4 to keep track of the status of his anaerobic digester system.
Larry left us these words, “whatever you decide to put in, keep it simple.”
401 W Armstrong Rd
Lodi, CA 95242