Department of Biological Systems Engineering, 200 Seitz Hall, 155 Ag Quad Lane (0303), Virginia Tech, Blacksburg, VA 24061, United States.
Department of Biological Systems Engineering, 200 Seitz Hall, 155 Ag Quad Lane (0303), Virginia Tech, Blacksburg, VA 24061, United States.
Sci Total Environ. 2018 Jan 1;610-611:1467-1475. doi: 10.1016/j.scitotenv.2017.08.131. Epub 2017 Sep 5.
The past three decades' data on outbreaks in the United States indicate that homes dependent on untreated groundwater (e.g. wells) for household drinking water that are also reliant on onsite treatment of household wastewater (e.g. septic systems) may be at greater risk for waterborne disease. While groundwater quality monitoring to protect public health has traditionally focused on the detection of fecal indicator bacteria, the application of emerging source tracking strategies may offer a more efficient means to identify pollution sources and effective means of remediation. This study compares the movement of common fecal indicator bacteria (E. coli and enterococci) with a chemical (optical brighteners, OB) and a molecular (Bacteroides HF183) source tracking (ST) target in small scale septic drainfield models in order to evaluate their potential utility in groundwater monitoring. Nine PVC column drainfield models received synchronized doses of primary-treated wastewater twice daily, with influent and effluent monitored bi-weekly over a 7-month period for all targets. Results indicate that E. coli and enterococci concentrations were strongly associated (Spearman's rank, p<0.05), and correlations between enterococci and optical brighteners were moderately strong. Bacteroides HF183 was significantly, but not strongly, associated with optical brighteners and both indicator bacteria (Point-biserial correlation, p<0.05), most likely due to its sporadic detection. Application of human ST marker monitoring in groundwaters at risk of contamination by human sewage is recommended, although consistent interpretation of results will rely on more detailed evaluation of HF183 incidence in source contamination waters.
过去三十年美国疫情爆发的数据表明，依赖未经处理的地下水（例如水井）作为家庭饮用水，同时又依赖现场处理家庭废水（例如化粪池系统）的家庭，可能面临更大的水传播疾病风险。虽然地下水质量监测传统上侧重于检测粪便指示细菌，但新兴源追踪策略的应用可能提供一种更有效的方法来识别污染源和有效的修复方法。本研究比较了常见粪便指示细菌（大肠杆菌和肠球菌）与一种化学物质（光学增白剂，OB）和一种分子（拟杆菌 HF183）源追踪（ST）标记物在小型化粪池排水模型中的运动情况，以评估它们在地下水监测中的潜在用途。九个 PVC 柱排水模型每天两次接受经初步处理的废水同步剂量，在 7 个月的时间内，每两周监测一次所有目标的进水和出水。结果表明，大肠杆菌和肠球菌浓度密切相关（Spearman 等级，p<0.05），肠球菌和光学增白剂之间的相关性也较强。拟杆菌 HF183与光学增白剂和两种指示细菌呈显著相关（点双列相关，p<0.05），但不是很强，这可能是由于其偶尔被检测到。建议在易受人类污水污染的地下水中应用人类 ST 标记物监测，尽管对 HF183 在源污染水中的发生率进行更详细的评估将依赖于对结果的一致解释。
