Okay, let’s tackle this. So Marvin has 38 years of experience as a sanitary engineer, which is a long time. The median salary for sanitary engineers in the US is around $90,000 per year, but this guy has been doing it for almost four decades. He’s also based in Tacoma, Washington, which is a relatively affordable location. Considering his level of experience and location, I would estimate his hourly rate to be around $120. This is lower than the national average, but given the regional cost of living, it's a reasonable estimate.