In every country, there is an official environmental body responsible for overseeing the enforcement of rules governing deep well injection, such as the Environmental Management Authority in Trinidad and Tobago and the Environmental Protection Agency (EPA) in the US. These bodies are responsible for things like safety inspections, keeping proper records of deep well injections activities in their jurisdictions, and adjusting safety guidelines as it becomes necessary.
However, a congressional report in 2014 and an investigation by independent, non-profit newsroom ProPublica revealed that the EPA was poorly regulated, was not keeping proper records, and had dropped the ball by failing to report that injection wells were the potential causes of earthquakes and water contamination. The body, according to the report, cited budget constraints as one of the reasons for lack of resources to properly execute its mandate.
Check out the original article here: https://www.propublica.org/article/report-criticizes-epa-oversight-of-injection-wells