title: Environmental fate of Ra in cation-exchange regeneration brine waste disposed to septic tanks, New Jersey Coastal Plain, USA: migration to the water table.
abstract: Fate of radium (Ra) in liquid regeneration brine wastes from water softeners disposed to septic tanks in the New Jersey Coastal Plain was studied. Before treatment, combined Ra ((226)Ra plus (228)Ra) concentrations (maximum, 1.54 Bq L(-1)) exceeded the 0.185 Bq L(-1) Maximum Contaminant Level in 4 of 10 studied domestic-well waters (median pH, 4.90). At the water table downgradient from leachfields, combined Ra concentrations were low (commonly < or =0.019 Bq L(-1)) when pH was >5.3, indicating sequestration; when pH was < or =5.3 (acidic), concentrations were elevated (maximum, 0.985 Bq L(-1) - greater than concentrations in corresponding discharged septic-tank effluents (maximum, 0.243 Bq L(-1))), indicating Ra mobilization from leachfield sediments. Confidence in quantification of Ra mass balance was reduced by study design limitations, including synoptic sampling of effluents and ground waters, and large uncertainties associated with analytical methods. The trend of Ra mobilization in acidic environments does match observations from regional water-quality assessments.
authors.affiliation: U.S. Geological Survey, 810 Bear Tavern Rd., Site 206, W. Trenton, NJ 08628, USA. zszabo@usgs.gov
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Szabo
authors.forename: Eric
authors.initials: E
authors.lastname: Jacobsen
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Kraemer
authors.forename: Bahman
authors.initials: B
authors.lastname: Parsa
mesh_terms: D005618:Fresh Water / Q000737:chemistry; D007474:Ion Exchange; D007700:Kinetics; D009515:New Jersey; D011834:Radiation Monitoring / Q000379:methods*; D011883:Radium / Q000032:analysis*; D012492:Salts / Q000737:chemistry*; D014865:Waste Disposal, Fluid; D014875:Water Pollutants, Radioactive / Q000032:analysis*
chemical_list: D012492:Salts; D014875:Water Pollutants, Radioactive; C017082:brine; D011883:Radium