Long-term land application of biosolids-a case study

• Published in: Water science and technology Vol. 57; no. 3; pp. 345 - 352
• Main Authors: Surampalli, R.Y, Lai, K.C.K, Banerji, S.K, Smith, J, Tyagi, R.D, Lohani, B.N
• Format: Journal Article
• Language: English
• Published: England IWA Publishing 01-01-2008
• Subjects: Agriculture; Agronomy; Biosolids; biosolids composts; case studies; Contamination; Drinking water; Environmental Pollutants - chemistry; Environmental Pollutants - pharmacology; fertilizer application; Groundwater; groundwater contamination; Heavy metals; human health; Leaching; Metal concentrations; nitrate nitrogen; Nitrogen; Pathogens; phosphorus; pollution load; Sewage - adverse effects; Sewage - chemistry; Sludge; Soil - analysis; Soil amendment; soil amendments; soil bacteria; Soil contamination; soil nutrients; soil pollution; Soil quality; Soil testing; temporal variation; Time Factors; wastewater treatment; Water - analysis; Water - chemistry; water quality; Water quality standards; Water sampling
• DOI: 10.2166/wst.2008.024
• EISSN: 1996-9732
• ISSN: 0273-1223

Impact of long-term land application of biosolids on groundwater and soil quality of an application site, which had been operated for 8-15 years, was evaluated in this study. During and after the biosolids application, biosolids-amended soil, groundwater, and background soil samples were collected mainly for pathogen, nitrogen, phosphorus, and heavy metal analyses. Soil test data showed that there was no heavy metal accumulation in the biosolids-amended soil even after 10 years of biosolids application. Similar results were also observed from the groundwater samples in which the heavy metal concentrations in all groundwater samples were well below the maximum contamination levels of the drinking water standards. In addition, bacteriological levels of the soil and groundwater samples were close to the background level and below the permissible limits, respectively, thereby showing no pathogen contamination. However, nitrate-nitrogen contamination of the groundwater was occasionally observed probably due to an excess loading of the biosolids in the past. This problem can be alleviated by applying biosolids at agronomic rates so that no excess nitrogen is available for leaching down to the groundwater.