The Environmental Protection Agency's inspector general says data released to the public about municipal sewer discharges is not accurate.

The agency watchdog sent a letter to the head of the EPA's Office of Chemical Safety and Pollution Prevention on Monday, warning that some information about hazardous substances released from publicly owned sewer systems is missing from a public database.

The watchdog says there were "discrepancies" between the total pounds of releases in the Toxics Release Inventory and internal data the EPA provided to the inspector general for the reporting years 2014-2017.

The agency publishes information about emissions and discharges of potentially harmful chemicals to water, air and land from private and public facilities nationwide.

An EPA spokesman says the agency corrected the information within three days of learning about it internally.