Yarmouth detects ‘rapid rise’ of COVID-19 markers in wastewater The number of coronavirus cases in the town has risen from seven to 21 in the last three weeks, according to a local task force. Share The town of Yarmouth is warning residents to redouble their efforts to prevent the spread of the coronavirus after samples taken from its wastewater treatment system showed “a steady and accelerating increase in key indicators of the presence of COVID-19 in our community.” The advisory, issued Saturday by the Yarmouth Community Coronavirus Task Force, said the increase has occurred over the past several weeks. The advisory was also posted on the town’s website.