State water pollution regulators in San Diego are asking federal officials to do more monitoring of cross-border water flows that could be polluted.

The San Diego Regional Water Quality Control Board issued an investigative order in February that requires more monitoring of sewage-tainted cross-border flows.

The order requires the International Boundary and Water Commission to monitor more than a dozen locations over an 18-month period.

Regional Board Executive Director David Gibson said the order also calls for the testing results to be made public.