A large percentage of dialysis technicians are failing a new competency test required by federal authorities, cutting into the patient-care workforce in California. Dialysis patients rely heavily on services provided at storefront facilities to do what their kidneys can no longer do ? clean their blood. Medicare and Medicaid are key funders of the service. Those federal programs decided in 2008 that all dialysis technicians must pass a test proving that they know what they're doing. But the test has proven challenging. The California Dialysis Council, which has administered its test to about 1,200 people so far, is seeing a pass rate of about 56%, according to the group's executive director.