"This is milk that's come in from the donors but this is quite low," Mother's Milk Bank Director Pauline Sakamoto said.
Sakamoto says donations have actually remained steady, but the program is in essence, a victim of its own success.
"The demand for human milk has gone exponentially high and we're just getting calls every day from more and more hospitals who want milk," she said.
Increasingly, those hospitals include advanced neural infant care units, like the one at UCSF's Benioff Children's Hospital in San Francisco. There, doctors treat premature infants whose body weights are just a fraction of a normal baby.
Lactation specialist Fritzi Drosten says the unit began adding milk from the bank about six months ago.
"We started purchasing donor milk for the very tiniest babies, the babies most at risk for getting serious infections," Drosten said.
When Dominique Hamilton isn't watching over her son in the NICU, she pumps milk for him. She says she'd be willing to donate extra for mothers who can't produce enough, an idea UCSF actively encourages.
"It's definitely a very good feeling to be able help other mothers who can't produce milk," Hamilton said.
The demand for donated milk has risen from about 1.5 million ounces a year in 2009, to more than 2 million ounces last year.
In centers like the one in San Jose, technicians pasteurize the milk and process it for distribution. Volunteers who contact the bank are asked to provide health information and take a free blood test.
Mothers pumping breast milk at home can send it to the bank in pre-paid coolers.
Sakamoto is hoping that a public appeal will bridge the shortfall before the end of the year.
"We're hoping for a 25 percent increase; we need to ramp up and make sure everybody understands who we are and what we do," Sakamoto said.
Written and produced by Tim Didion