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Pipe scale analysis
A calcium phosphate solid formed as an unintended consequence of a novel high-pH orthophosphate lead corrosion control strategy in Providence, RI, causing some consumer complaints and clogged plumbing. The calcium phosphate initially precipitated at orthophosphate doses above about 2 mg/L as PO4 during field testing, and the extent of precipitation increased with water age and higher temperature. Lab scale tests confirmed that doses above about 2 mg/L were required to form the precipitate in the absence of pre-existing calcium phosphate solids, and that the solid formed quickly at 60 °C (upper range for hot water heaters) and tended to dissolve at lower pH. Solubility modeling and other techniques suggest the solids are a mixture of compounds. For water systems currently practicing a high pH/low alkalinity corrosion control strategy, orthophosphate dosing can enhance plumbosolvency control without risky pH reduction, but calcium hardness puts a constraint on the maximum orthophosphate level that can be applied and tolerated.
This dataset is associated with the following publication:
Devine, C., K. Mello, M. Desantis, M. Schock, J. Tully, and M. Edwards. Calcium Phosphate Precipitation as an Unintended Consequence of Phosphate Dosing to High-pH Water. ENVIRONMENTAL ENGINEERING SCIENCE. Mary Ann Liebert, Inc., Larchmont, NY, USA, 41(5): 171-215, (2024).
Complete Metadata
| accessLevel | public |
|---|---|
| bureauCode |
[
"020:00"
]
|
| contactPoint |
{
"fn": "Christina Devine",
"hasEmail": "mailto:devine.christina@epa.gov"
}
|
| description | A calcium phosphate solid formed as an unintended consequence of a novel high-pH orthophosphate lead corrosion control strategy in Providence, RI, causing some consumer complaints and clogged plumbing. The calcium phosphate initially precipitated at orthophosphate doses above about 2 mg/L as PO4 during field testing, and the extent of precipitation increased with water age and higher temperature. Lab scale tests confirmed that doses above about 2 mg/L were required to form the precipitate in the absence of pre-existing calcium phosphate solids, and that the solid formed quickly at 60 °C (upper range for hot water heaters) and tended to dissolve at lower pH. Solubility modeling and other techniques suggest the solids are a mixture of compounds. For water systems currently practicing a high pH/low alkalinity corrosion control strategy, orthophosphate dosing can enhance plumbosolvency control without risky pH reduction, but calcium hardness puts a constraint on the maximum orthophosphate level that can be applied and tolerated. This dataset is associated with the following publication: Devine, C., K. Mello, M. Desantis, M. Schock, J. Tully, and M. Edwards. Calcium Phosphate Precipitation as an Unintended Consequence of Phosphate Dosing to High-pH Water. ENVIRONMENTAL ENGINEERING SCIENCE. Mary Ann Liebert, Inc., Larchmont, NY, USA, 41(5): 171-215, (2024). |
| distribution |
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"title": "RIPRFHP1_XRF data_2.25.19.xlsx",
"mediaType": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
"downloadURL": "https://pasteur.epa.gov/uploads/10.23719/1528531/RIPRFHP1_XRF%20data_2.25.19.xlsx"
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"title": "TIC RIPRFHP1_ 1-13-2020.xlsx",
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"downloadURL": "https://pasteur.epa.gov/uploads/10.23719/1528531/TIC%20RIPRFHP1_%201-13-2020.xlsx"
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|
| identifier | https://doi.org/10.23719/1528531 |
| keyword |
[
"Calcium",
"Orthophosphate",
"high pH",
"solids analysis"
]
|
| license | https://pasteur.epa.gov/license/sciencehub-license.html |
| modified | 2019-09-06 |
| programCode |
[
"020:000"
]
|
| publisher |
{
"name": "U.S. EPA Office of Research and Development (ORD)",
"subOrganizationOf": {
"name": "U.S. Environmental Protection Agency",
"subOrganizationOf": {
"name": "U.S. Government"
}
}
}
|
| references |
[
"https://doi.org/10.1089/ees.2023.0190"
]
|
| rights |
null
|
| title | Pipe scale analysis |
