A boom in charter schools has cost the Los Angeles Unified School District more than a half-billion dollars in the past year alone, according a report commissioned and released today by the district’s

teachers union, which strongly opposes charter schools. “This report is a first step in a necessary process to understand what it would take to have a sustainable system for all students, both in charters

and in district schools,” said Alex Caputo-Pearl, president of United Teachers Los Angeles. “It took over 12 years of declining enrollment at LAUSD to get an accounting of the financial strain of charter school growth. We cannot wait another 12 years to address the consequences it is having on public education

and our students.” A spokeswoman for LAUSD said the district had no comment on the study. Union officials are expected to make a presentation on the report to the LAUSD Board of Education this afternoon. According to the study, which was commissioned by UTLA and performed by MGT of America, 16 percent of LAUSD students attend charter schools, 56 of which operate rent-free on district campuses. The LAUSD the second-largest school district in the nation has the most charter schools, 221, of any district in the country. The number of charter schools has tripled over the last decade. According to the report, among the funds the district lost in 2014-15 due to charter schools include:

— $508.3 million in student enrollment funds;

— $15.3 million in oversight costs not paid by charters;

— $2.1 million in oversight costs for co-located schools;

— $10.4 million in additional special education costs; and

— $86,000 in in-lieu property taxes.

“When there is escalating competition for students and funding, both charter and district schools are faced with creating a situation where, if changes are not enacted immediately, the entire educational system in Los Angeles will be in a financial crisis,” said Donald Cohen, executive director of In the Public Interest, a Washington, D.C.-based research and public policy center.