Boron and lithium isotopes as groundwater tracers: a study at the Fresh Kills Landfill, Staten Island, New York, USA

• Published in: Applied geochemistry 2003-04, Vol.18 (4), p.615-627
• Main Authors: Hogan, James F, Blum, Joel D
• Format: Article
• Language: English
• Subjects: Earth sciences; Earth, ocean, space; Exact sciences and technology; Geochemistry; Hydrogeology; Hydrology. Hydrogeology; Mineralogy; Silicates; Water geochemistry
• ISSN: 0883-2927; 1872-9134
• DOI: 10.1016/S0883-2927(02)00153-1

A study was conducted at the Fresh Kills landfill, Staten Island, New York to investigate the use of B and Li isotopes as tracers of mixing and flow in the groundwater environment. Four end-member waters are present at the Fresh Kills: freshwater, seawater, a geochemically distinct transitional groundwater (that occurs in the zone of mixing between seawater and freshwater) and landfill leachate. The δ 11B and δ 6Li values of end-member waters are distinct and have isotopic compositions that reflect the solute sources: freshwater δ 11B∼+30‰, δ 6Li∼−22‰; transition zone groundwaters δ 11B∼+20‰, δ 6Li∼−27‰; seawater δ 11B+40 to +75‰, δ 6Li−37 to−44‰; leachate δ 11B∼+10‰ (δ 6Li not determined). Those wells influenced by seawater exhibited a clear chemical mixing trend, with seawater contributions ranging from 3 to 85%. Well waters with a high percentage of seawater (>30%) had δ 11B values that were within 1‰ of the seawater value (+40‰), whereas a trend of increasing δ 11B values (+55 to +75‰) was observed for wells with a lower percentage of seawater (