title: Evaluation of ground water denitrification at a biosolids disposal site.
abstract: A study was conducted at a sanitary sewage sludge (biosolids) disposal site in Springfield, Illinois, U.S.A. to determine if biological denitrification played a significant factor in attenuation of ground water nitrate values. The site selected for this study is a 23 ha (57 acre) dedicated biosolids disposal facility located adjacent to a 75.7 million liter per day (20 million gallons per day) municipal treatment plant that uses anaerobic solids stabilization for treatment of generated biosolids material. Biosolids have been disposed of by fixed-point spray applicators at the site since 1976, which has caused ground water nitrate levels to increase significantly above background levels. A method was developed using a conservative chemical tracer to simulate the biosolids application process and monitor the ground water directly beneath the simulated disposal site. Results demonstrated a net decline of nitrates that could not be attributed to dilution alone. While the monitoring methodology developed for this study did not directly estimate the denitrification rate, a rate for overall nitrate reduction was calculated that could be considered to take into account all transport and reduction mechanisms such as denitrification, advection, dispersion and dilution.
authors.affiliation: Crawford, Murphy and Tilly, Inc., Springfield, Illinois, USA.
authors.forename: Allen O
authors.initials: AO
authors.lastname: Oertel
authors.forename: John W
authors.initials: JW
authors.lastname: Nicklow
mesh_terms: D004784:Environmental Monitoring; D006256:Hazardous Waste / Q000032:analysis*; D006801:Humans; D007087:Illinois; D009566:Nitrates / Q000737:chemistry*; D012037:Refuse Disposal; D012722:Sewage; D014876:Water Pollution / Q000032:analysis*
chemical_list: D006256:Hazardous Waste; D009566:Nitrates; D012722:Sewage