What is a high level of EtG in urine?

Could you please elaborate on what is meant by a "high level of EtG in urine"? What does EtG stand for, and why is it significant to have a high level of it in one's urine? What could potentially cause a high level of EtG in urine, and what are the potential implications or consequences of such a finding? How is the level of EtG in urine typically measured, and what factors could potentially affect the accuracy of such measurements? Thank you for your insight.