A Change in Your Water Treatment: What's Happening and Why

A Change in Your Water Treatment: What's Happening and Why

Because of drought conditions and a major upgrade underway at our treatment plant, some customers may notice changes in their tap water: specifically, more hardness deposits in filters and occasional rust-colored water. To address these changes, the City is adding a safe, EPA-approved treatment to protect your water and your pipes.

Here's what you need to know.

What is changing?

The City is adding a blended mix of orthophosphate and polyphosphate, which are two common and safe mineral-based additives. These substances are commonly used by water utilities across the country to soften "hard" water and to protect pipes and keep water clear.

What is "hard water," and what causes it?

Hardness comes from calcium and magnesium, natural minerals that dissolve into water as it moves through soil and rock long before it ever reaches our treatment plant. It is not a contaminant and not a health concern. It can, however, leave spots on dishes, reduce soap lather, and cause scale buildup in pipes, faucets, and appliances.

Why is this happening?

Southwest Florida is in a severe drought, so our regional supplier, Tampa Bay Water, has had to change the mix of water sources it blends together for our area. Groundwater is naturally harder than surface water because it picks up more minerals as it flows through underground soil and rock, and with less surface water available during the drought, a larger share of our supply is now coming from groundwater. At the same time, the decades-old softening equipment at our Cosme Water Treatment Plant is temporarily offline for a major rehabilitation. Together, these two temporary conditions can cause harder water, mineral buildup, or occasional discolored water.

What are orthophosphate and polyphosphate, and why add them?

They are safe, common water-treatment additives used by utilities nationwide. Polyphosphate binds with naturally occurring iron and manganese so they stay dissolved instead of discoloring your water. Orthophosphate forms a thin, protective mineral coating on the inside of pipes that reduces corrosion. Together, this blend helps offset the temporary loss of softening at the Cosme Water Treatment Plant and the shift in Tampa Bay Water's supply blend, while also better protecting our distribution pipes going forward.

When is this happening?

To address these changes, starting Tuesday, September 8, the City is adding a safe, EPA-approved treatment to protect your water and your pipes.

Is hardness or iron in water a health hazard?

No. The EPA classifies both as "secondary" standards, meaning they can affect taste, color, or appearance but are not linked to health risks. Your water is tested continuously and continues to meet all Florida Department of Environmental Protection and EPA safety requirements.

What should I do if I notice discolored water?

For the first two to three weeks as the new treatment starts up, you may briefly notice discoloration. If this happens, run a cold water tap (bathtub or outside hose bib) for several minutes until it runs clear, and avoid using hot water so discoloration doesn't reach your water heater. If the issue continues, call us and we'll send a technician.

Questions? We're here to help. Contact the St. Petersburg Water Resources Department at 727-893-7261.