Is there any regulation in Harris County about restaurants providing number of restrooms based on their capacity?

Went to a restaurant yesterday that had about 80 people in the dining area. But they only provide one restroom (one sink and one toilet). I was in line to use the restroom and guy infront said they are breaking Harris County regulation. Number of restrooms has to be based on capacity. I noticed the employees were also using the same restroom.

Is there any such regulation?