Public-health agencies in at least six states have shut beaches or posted swimming advisories days before the July 4 holiday after tests found fecal bacteria far above safety limits. Advisories cover popular ocean and freshwater sites from California to Massachusetts, raising the prospect of crowded waterfronts with no access to the water during one of the year’s busiest travel weekends. Massachusetts has imposed the broadest restrictions, closing 26 beaches as of July 3, with state data showing 21 shuttered for bacterial exceedance and two for harmful cyanobacteria blooms. Four New York beaches and at least eight in Illinois are also off-limits, while Washington state has posted multiple warnings. In California, Los Angeles County is maintaining eight ocean-water quality advisories and San Diego County has closed two shoreline parks after cross-border sewage flows from Mexico. Officials attribute the spike to runoff from heavy rain, sewage overflows and warm summer water that accelerates the growth of E.coli and Enterococcus. The contaminants can cause gastrointestinal illness and skin infections; laboratories must confirm that bacterial counts have returned to acceptable levels before the bans are lifted. Health departments are urging holidaymakers to check local dashboards and avoid water contact at any site under advisory or closure.