Dairy washwater is generated each time the dairy cows are washed prior to milking. OCWD is conducting the project because the dairy washwater contributes salts and nitrates to the Chino groundwater basin. Some of that washwater eventually impacts the flows of the Santa Ana River -- the principal water supply for Orange County's large groundwater basin.
"We see increased salts and nitrates in our water supply as a `cost shifting' issue. We have to clean up after the dairies at the expense of Orange County water users," said Irv Pickler, president of the Board of Directors of the Orange County Water District. "If we can help solve this problem before the washwater migrates to the river, we can reduce our treatment costs and prolong the useful life of our customers' pipes, plumbing and home appliances."
Dairy washwater is water used to wash down dairy cows, usually twice a day, prior to milking. Between 50 and 100 gallons of water are used to wash down each cow prior to milking, which amounts to between 15-30 million gallons per day of washwater generated in the Chino Basin, home to about 270 dairies and more than 330,000 cows.
The demonstration project will implement wetlands treatment of dairy washwater and evaluate reductions in organic materials, nitrate levels, bacteria, viruses, ammonia and other compounds before the water is reused or returned to the environment. One of the goals will be to develop successful wetlands treatment technology that can be transferred to other dairy sites around the state.
SOURCE: Orange County Water District