{"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 \u00b0C (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. \n\nThis dataset is associated with the following publication:\nDevine, 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": [{"downloadURL": "https://pasteur.epa.gov/uploads/10.23719/1528531/RIPRFHP1_XRF%20data_2.25.19.xlsx", "mediaType": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", "title": "RIPRFHP1_XRF data_2.25.19.xlsx"}, {"downloadURL": "https://pasteur.epa.gov/uploads/10.23719/1528531/TIC%20RIPRFHP1_%201-13-2020.xlsx", "mediaType": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", "title": "TIC RIPRFHP1_ 1-13-2020.xlsx"}, {"downloadURL": "https://pasteur.epa.gov/uploads/10.23719/1528531/XRD%20data.csv", "mediaType": "text/csv", "title": "XRD data.csv"}], "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"}