The summer surge of COVID-19 doesn't appear to be slowing down — instead, a key indicator for tracking the spread of the virus has increased, according to the latest data from the Centers for Disease Control and Prevention.

In an update shared Friday, official data showed wastewater activity for COVID-19 is now at a "moderate" level nationwide, up from "low" the previous week.

Wastewater levels for the virus are currently the highest in the Western U.S., the data also showed. States in this region showing high levels include: Alaska, California, Colorado, Nevada and Utah.