Two cancer-causing components have been found in Sebastopol’s aging water wells, raising red flags among city council leadership, especially as the city lacks funding to fix its infrastructure. Specifically, traces of arsenic were detected in three of the city’s wells, according to a recently released city report. Tetrachloroethylene, commonly known as PCE, has been detected in one of those three wells, too. But the levels of both arsenic and PCE in the city’s drinking water remain under thresholds deemed dangerous by state and federal regulators, city officials say. That’s because filtering or treatment systems have been installed to remove the bulk of the contaminants, and water from the wells is blended to reduce them even more.