Department of Civil and Environmental Engineering, The University of Iowa, Iowa City, Iowa, USA.
Environ Sci Technol. 2010 Oct 1;44(19):7193-9. doi: 10.1021/es100164c.
State water quality monitoring has been augmented by volunteer monitoring programs throughout the United States. Although a significant effort has been put forth by volunteers, questions remain as to whether volunteer data are accurate and can be used by regulators. In this study, typical volunteer water quality measurements from laboratory and environmental samples in Iowa were analyzed for error and bias. Volunteer measurements of nitrate+nitrite were significantly lower (about 2-fold) than concentrations determined via standard methods in both laboratory-prepared and environmental samples. Total reactive phosphorus concentrations analyzed by volunteers were similar to measurements determined via standard methods in laboratory-prepared samples and environmental samples, but were statistically lower than the actual concentration in four of the five laboratory-prepared samples. Volunteer water quality measurements were successful in identifying and classifying most of the waters which violate United States Environmental Protection Agency recommended water quality criteria for total nitrogen (66%) and for total phosphorus (52%) with the accuracy improving when accounting for error and biases in the volunteer data. An understanding of the error and bias in volunteer water quality measurements can allow regulators to incorporate volunteer water quality data into total maximum daily load planning or state water quality reporting.
美国各地的志愿者监测计划已经补充了国家水质监测。尽管志愿者付出了巨大的努力，但仍存在一些问题，即志愿者数据是否准确，以及监管机构是否可以使用这些数据。在这项研究中，分析了爱荷华州实验室和环境样本中典型的志愿者水质测量结果的误差和偏差。志愿者对硝酸盐+亚硝酸盐的测量值明显低于（约 2 倍）实验室和环境样本中通过标准方法确定的浓度。志愿者分析的总活性磷浓度与实验室制备样本和环境样本中通过标准方法确定的测量值相似，但在五个实验室制备样本中的四个样本中，其浓度统计上低于实际浓度。志愿者水质测量成功地识别和分类了大多数违反美国环境保护署建议的总氮（66%）和总磷（52%）水质标准的水，当考虑到志愿者数据中的误差和偏差时，准确性有所提高。了解志愿者水质测量中的误差和偏差，可以使监管机构将志愿者水质数据纳入总最大日负荷规划或州水质报告中。
