By the end of September of this year, Providence Water will apply orthophosphate (phosphoric acid) in a very small dose to enhance the corrosion control treatment throughout the Providence distribution and wholesale system.  Providence Water began research on improved corrosion control treatment back in 2005.  This research led to the formation of a panel of national recognized industry experts to evaluate the potential benefits of the addition of orthophosphate to mitigate corrosion in pipes, service lines and household plumbing.  Orthophosphate is commonly used in water systems throughout the US and the world.  Both bench scale testing, and full scale testing in a section of their distribution system, provided positive results with no documented negative consequences.  The Providence studies showed a significant reduction in metals leaching from piping, including lead and iron.  As such, Providence Water is moving forward with system wide orthophosphate utilization.

The following are some frequently as questions related to the addition and utilization of orthophosphate for corrosion control practices:


What is orthophosphate and why is it being added to our drinking water?

Providence Water has had issues with elevated lead levels in some household plumbing due to lead service lines.  Orthophosphate forms a protective coating inside water pipes. This coating helps reduce corrosion that can release lead and other metals into the water.


Why did Providence Water select Orthophosphate?

In 2013, Providence Water organized a panel of nationally recognized drinking water experts (Expert Panel) to find the best form of corrosion control treatment for the distribution system.  Following extensive testing and evaluation, the Expert Panel recommended the use of orthophosphate, which was then approved by the Rhode Island Department of Health.  Orthophosphate is approved by the EPA as the optimal corrosion control treatment for reducing lead and is used successfully throughout the United States.


Why is orthophosphate good for the BCWA system?

The BCWA has removed the few lead service lines (pipe from the main to the building) that had been installed in the system.  We are presently removing lead connections from the main to the service line (about 100 left).  However, galvanized service lines have recently been cited as a concern and are also in the process of being removed.  Orthophosphate will help reduce the  corrosion of cast iron mains (about 1/3 of the BCWA distribution system), galvanized iron piping, and fixtures in homes that may contain lead.


Is Orthophosphate Safe?

Yes. Orthophosphate is approved for use by the Food and Drug Administration, EPA, and the National Sanitation Foundation (NSF).  NSF is an independent international testing organization that certifies and writes standards for products, food, air, water and consumer goods in use. According to the EPA, the typical phosphate levels found in a liter of drinking water are about one hundred times lower than the phosphate levels found in the average American diet. For example, a person would have to drink ten to fifteen liters of water to equal the amount of phosphates in just one can of soda.


Will orthophosphate have any effect on my drinking water?

Orthophosphate should not affect the taste, color or smell of your drinking water.


Where else is Orthophosphate Used?

Orthophosphate is used throughout the country. According to a 2010 survey conducted by the New England Water Works Association, more than half of the 194 New England water suppliers listed use a phosphate corrosion inhibitor.


Will Orthophosphate in drinking water impact individual septic systems?

There is no evidence that orthophosphate levels found in drinking water will negatively impact septic system functionality.


Additional questions or concerns related to this topic can be directed to the Bristol County Water Authority @ 401-245-2022 or Providence Water @ 401-521-6300.