Environmental Health Workforce Act of 2019 This bill requires the Department of Health and Human Services (HHS) to develop model standards and guidelines for credentialing environmental-health workers. Additionally, HHS must develop a plan for the environmental-health workforce that includes performance measures and identifies (1) gaps between existing programs and future environmental-health workforce needs, (2) actions needed to address any identified gaps, and (3) any additional statutory authority necessary to implement such actions. The bill also specifies that environmental-health workers are eligible for public-service loan forgiveness.