St. Petersburg Adds Phosphates to Tap Water Tuesday

St. Petersburg will begin treating tap water with orthophosphate and polyphosphate on Tuesday, September 8, to address hard water and occasional discoloration.

The EPA-approved mineral additives soften hard water and protect pipes. Polyphosphate keeps naturally occurring iron and manganese dissolved so they don't discolor water. Orthophosphate forms a protective coating inside pipes to reduce corrosion.

The city's Cosme Water Treatment Plant has taken its decades-old softening equipment offline for a major rehabilitation. Simultaneously, drought conditions have forced Tampa Bay Water, the regional supplier, to shift toward groundwater sources. Groundwater contains more calcium and magnesium than surface water, making it naturally harder.

Hard water and iron are not health hazards. The EPA classifies both as secondary standards, meaning they affect taste, color, or appearance but pose no health risks. St. Petersburg's water meets all Florida Department of Environmental Protection and EPA safety requirements.

Residents may notice rust-colored water or more hardness deposits in filters for the first two to three weeks. The Water Resources Department recommends running a cold water tap at a bathtub or outside hose bib for several minutes until water runs clear, and avoiding hot water use so discoloration doesn't reach the water heater. Call 727-893-7261 for continued issues.