Yeah, the problem with the nationwide stuff is the more you zoom out from the source the less resolution you have for your data. Like honestly it feels kind of reckless for researchers to be making nationwide claims based on wastewater nowadays when there are so many states with only a handful of monitoring sites. A single monitoring site doesn't tell us anything about the distribution of cases within that site's territory and the estimates only become dramatically more inaccurate the larger the territory the monitoring site is estimated to represent. Especially when we're outside of the typical large surges and the handful of monitoring stations you have in a geographic area aren't showing synchronous elevation in levels of infection.