I spoke to the head chemist at the local water treatment plant about it, he said that the source water (Grand River) is contaminated from mostly agricultural runoff. He also said the concentration of NH4 does not exceed "Maximum Acceptable Concentration" or MAC according to provincial regulations and has been deemed acceptable for human consumption. Unfortunately I found out the hard way that it's not acceptable to my sensitive species of fish.
I personally don't drink tap water because I have health problems, but for most healthy people I don't think it would be an issue.
I have spoke to the head chemist quite a few times, he has always been really helpful in answering my questions and seems really happy to talk to someone that has an interest in water quality.
I think everyone should contact their local water treatment authority for more info in this hobby, I have really learned a lot about my water in doing so. He also gave me online links to all of the water chemistry reports for the city, I wish I contacted them a lot sooner than I did.