MaineDMR Public Health - 2016 P90 Scores

The Department of Marine Resources (DMR) Bureau of Public Health collects water samples at approximately 1,400 water quality stations along the Maine coast. At each station, after at least 30 samples have been collected under systematic random sampling and analyzed for fecal coliforms, DMR scientists calculate final scores which, along with sanitary surveys of the area, help determine whether the water quality is acceptable for harvesting shellfish. Fecal coliform results are reported as the number of colony forming units (individual bacterium capable of forming colonies) per 100mL of water. Most sample sites show a range of scores, and some sites may have high as well as low scores. The DMR Shellfish Growing Area Classification Program classifies shellfish areas as Approved, Conditionally Approved, Restricted, Conditionally Restricted or Prohibited using standards set by the National Shellfish Sanitation Program (NSSP), a federal/state cooperative program that sets the requirements for all states involved in interstate shellfish harvest and sale. All classifications are based on two factors: the results of a shoreline survey which looks for the presence of pollution sources and fecal coliform test results. For more information about the classification of shellfish flats, visit https://www.maine.gov/dmr/shellfish-sanitation-management/programs/growingareas/index.html. For each water quality station, two statistical values are calculated from the most recent 30 fecal scores: the geometric mean (geomean) and the 90th percentile (P90). The standards for Approved are 14 or less (geomean) and 31 or less (P90). The standards for Restricted are 88 or less (geomean) and 163 or less (P90). The standards for Prohibited are greater than 88 (geomean) and greater than 163 (P90). End of year 2016 P90 data for all Maine active water quality stations are based on the most recent 30 samples. Conditional Area stations are based on last 30 samples in the open status. Data projection is NAD 1983 UTM Zone 19N.缅因州海洋资源部（Department of Marine Resources, DMR）公共卫生局会在缅因沿岸约1400个水质监测站开展水样采集工作。每个监测站采用系统随机采样法采集至少30份水样，完成粪大肠菌群检测分析后，DMR科研人员将计算最终得分，结合该区域的卫生调查结果，共同判定该水域是否适合贝类采收。粪大肠菌群的检测结果以每100毫升水中的菌落形成单位（colony forming units，即可形成菌落的单个细菌）数量为单位进行报告。多数监测站点的得分存在区间差异，部分站点的得分兼具高值与低值。 DMR贝类养殖区分类项目依据全国贝类卫生计划（National Shellfish Sanitation Program, NSSP）制定的标准，将贝类养殖区划分为批准类、有条件批准类、限制类、有条件限制类及禁止类。全国贝类卫生计划是一项联邦-州级合作项目，为所有参与跨州贝类采收与销售的州制定相关规范。所有分类均基于两项依据：一是针对污染源排查的岸线调查结果，二是粪大肠菌群检测结果。若需了解更多贝类养殖滩涂的分类信息，请访问：https://www.maine.gov/dmr/shellfish-sanitation-management/programs/growingareas/index.html。 针对每个水质监测站，科研人员会基于最新的30份粪大肠菌群得分计算两项统计指标：几何均值（geometric mean，简称geomean）与90分位数（90th percentile，简称P90）。各类别对应的判定标准如下：批准类的几何均值≤14、90分位数≤31；限制类的几何均值≤88、90分位数≤163；禁止类的几何均值＞88且90分位数＞163。 2016年末，缅因州所有活跃水质监测站的90分位数数据均基于其最近采集的30份水样。有条件养殖区站点的判定依据为其处于开放状态时采集的最近30份水样。本数据集采用NAD 1983 UTM Zone 19N坐标系进行投影。