Generally, radon is not a problem with public drinking water systems because during the water treatment process aeration releases dissolved radon to the atmosphere. However, if the water supply is from a private well, radon levels could be unacceptably high. The EPA has published a map characterizing all Colorado counties. If you identify the county, I can tell you how EPA characterized that county. There is also some older data which, although incomplete, may prove helpful.
Schools are at risk from radon just as homes are.
Colorado statute requires all schools to have tested for radon, and to maintain records of the test results for disclosure on request. The regulation does not require schools that find a problem to mitigate according to a mandated schedule. It is up to the District and its constituents to address mitigation issues. About fifty percent of the schools that were found to have a problem have mitigated. Further information on radon in schools can be found in the EPA Radon Publication Radon Measurement in Schools.