Straight from the Tap

What We Do About Lead: Water Treatment

10/22/2018

At Cleveland Water, we take the risks associated with lead in drinking water seriously. That is why we have optimized our water treatment process to help protect you and your family from the risks associated with lead pipes.

Add Orthophosphate

Drinking water is lead-free when it leaves our treatment plants, but tap water can pick up lead as it travels through lead service lines, plumbing, and fixtures. We add a chemical called orthophosphate to minimize the chances of this happening.

We've been adding orthophosphate at the end of the drinking water treatment process since 1997. Orthophosphate forms a protective coating inside metal service lines and water pipes that prevents water from coming in direct contact with the pipe material, reducing the likelihood of lead being dissolved into the water.

Testing shows that orthophosphate treatment is very successful at reducing lead from leaching into drinking water. If the orthophosphate coating inside a lead service line or lead plumbing is disturbed and flakes off, the coating will reform.

The amount of orthophosphate added to water for your protection is very small – about 1 mg to 1.5 mg per liter. By comparison, one liter of pop contains up to 1,000 times that amount.

Control pH

We control the pH of treated drinking water to help control corrosion. Water that has a pH below 7 (on the pH scale of 0 to 14) is more acidic and therefore more likely to corrode metal. The pH of water leaving our treatment plants is always above 7, usually between 7.3 and 7.6.

The pH of Lake Erie water naturally varies between 7.5 and 8.4; usually on the higher end of the range during summer and more toward 7.5 during winter. This means water coming into our treatment plants is naturally slightly alkaline rather than acidic.

If we need to, we can adjust the pH of the water to reduce corrosiveness and ensure the water we deliver to our customers is within the optimal range for preventing lead from leaching into water.

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