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

Cleveland 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 orthophosphate at the end of the drinking water treatment process to minimize the chances of this happening.

Cleveland Water has been adding orthophosphate since 1997. Orthophosphate inhibits the water from coming into contact with metal water pipes, service lines, and your home’s plumbing by forming a protective coating inside. This coating prevents water from coming in contact with the pipe material, reducing the likelihood of lead being dissolved into the water supply.

Test results show our orthophosphate treatment is very successful at reducing lead from leaching into the water. Even in houses that have lead plumbing, lead sample results are very low. If the orthophosphate coating inside a lead service line or lead plumbing is disturbed and flakes off, our water’s continuous orthophosphate feed will reform the coating.

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

Cleveland Water controls the pH of finished 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 water we deliver to customers is within the optimal range for preventing lead from leaching into water, which is also the optimal range for our orthophosphate treatment.

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