The short response is that typically most beaches while in the Turks and Caicos do not have any obvious sargassum, but some coasts do obtain varying quantities of the seaweed at some moments. Many homes and villas on Providenciales use ‘city water’, but not all. Cistern drinking water is usual https://holdenwdgil.wikibriefing.com/2815765/not_known_details_about_weed_laws_turks_and_caicos