The Arizona Dept of Health Services issued its school benchmarks for school reopenings on August 6, 2020 and they are found here.
Websites for various Arizona school districts, to check on their various policies and schedules, can be found in this article which seems to be updated as of August 5, 2020.
This chart shows the benchmarks for positive cases per 100,000 population and % positivity, with schools to stay at all distance learning when in the red, and return-to-school in person when in the green.
Arizona Superintendent of Schools Kathy Hoffman’s August 3 announcement regarding schools can be found here, and her Twitter feed is @Supt_Hoffman.