MaineDMR Public Health - 2022 P90 Scores

The Department of Marine Resources (DMR) Bureau of Public Health collects surface water grab samples at approximately 1,200 water quality monitoring stations along the Maine coast year-round. Samples are processed in the lab via membrane filtration and enumerated for fecal coliform bacteria. Fecal coliform results are reported as the number of colony forming units (individual bacterium capable of forming colonies) per 100mL of water. DMR scientists analyze data from each station and calculate annual summary statistics using at least 30 of the most recent samples collected under a systematic-random sampling strategy. These values, along with sanitary surveys of the area, help determine whether the water quality is acceptable for harvesting molluscan shellfish. DMR's 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. For more information about the classification of shellfish flats, visit https://www.maine.gov/dmr/fisheries/shellfish/shellfish-growing-area-classification. All classifications are based on two factors: the results of a shoreline survey which looks for the presence of pollution sources, and fecal coliform monitoring results. Two statistical values are calculated from the most recent 30 fecal coliform scores: the geometric mean (geomean) and the 90th percentile (P90). The standards for Approved classification are 14 CFU or less (geomean) and 31 CFU or less (P90). The standards for Restricted are 88 CFU or less (geomean) and 163 CFU or less (P90). The standards for Prohibited are greater than 88 CFU (geomean) and greater than 163 CFU (P90). End of year 2022 P90 data for all Maine active and investigative water quality stations 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）公共卫生局全年在缅因海岸沿线约1200个水质监测站点采集表层水体瞬时水样。样本在实验室通过膜过滤法处理，并计数粪大肠菌群数量。粪大肠菌群的检测结果以每100mL水体中的菌落形成单位（Colony Forming Unit, CFU）数量报告，菌落形成单位即具备形成菌落能力的单个细菌。DMR的科研人员会分析各站点的数据，并基于系统随机抽样策略采集的最新至少30份样本，计算年度汇总统计量。上述统计值结合区域卫生调查结果，可用于判断水体质量是否适宜开展双壳类贝类采收活动。DMR的贝类养殖区分类项目依据国家贝类卫生计划（National Shellfish Sanitation Program, NSSP）制定的标准，将贝类养殖区划分为获批（Approved）、条件获批（Conditionally Approved）、限制级（Restricted）、条件限制级（Conditionally Restricted）以及禁止级（Prohibited）五类。国家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捕捞与销售的州制定相关规范。如需了解贝类滩涂分类的更多信息，请访问：https://www.maine.gov/dmr/fisheries/shellfish/shellfish-growing-area-classification。所有分类均基于两项核心依据：一是旨在排查污染源的岸线调查结果，二是粪大肠菌群监测数据。从最新的30份粪大肠菌群检测结果中可计算得到两项统计指标：几何均值（geometric mean, 简称geomean）与90分位数（90th percentile, 简称P90）。获批类别的水质标准为：几何均值≤14 CFU，且90分位数≤31 CFU；限制级类别的标准为：几何均值≤88 CFU，且90分位数≤163 CFU；禁止级类别的标准为：几何均值＞88 CFU，且90分位数＞163 CFU。本数据集为2022年末缅因州所有活跃及调查性质控水质站点的P90数据，基于最新采集的30份样本计算得到；条件区域站点的数据基于其处于开放状态时的最近30份样本。数据投影采用NAD 1983 UTM Zone 19N坐标系。