The sewage spills and brown water advisories pose significant public health risks, particularly for swimmers and beachgoers. Polluted runoff can lead to gastrointestinal illnesses, and the presence of fecal bacteria in coastal waters is a major concern. The affected areas include Oahu's Ala Moana and Sandy Beach, where signs have been posted to warn the public. The delays in water testing further complicate efforts to assess and mitigate the risks. Residents are advised to avoid all contact with brown or murky water until advisories are lifted.