Concentration of nutrients in water samples collected from the upper Clark Fork River (Montana, USA) during water years 2017 and 2018 (1 Oct 2016 - 30 Sep 2018)

The LTREB monitoring project is a portion of the 200 million-dollar superfund project for ecological restoration of the Clark Fork River, associated tributaries, and head water streams including Silver Bow and Warm Springs Creek. Restoration along the Clark Fork River includes removal of metal-laden floodplain soils, lowering of the floodplain to its original elevation, and re-vegetation of over 70 km of the river's floodplain closest to contaminant sources. The LTREB monitoring project consists of bi-weekly water quality monitoring across a 200-km restoration gradient contaminated by historic mining practices to monitor inorganic phosphorus and nitrogen concentrations, biotic standing stocks, and heavy metal contamination. The LTREB monitoring project is conducted within the first 200km of the Clark Fork River and associated tributaries located in Western Montana. This LTREB monitoring program began in 2017 and will be completed in the year 2022 with potential for funding extension. Surface water samples represented in this data product are collected from thirteen sites along the mainstem of the upper Clark Fork River. Water samples are collected at each monitoring site in triplicate and filtered with a 0.7 µm glass fiber filter. Nutrient samples are analyzed using a spectrophotometric flow injection analyzer (AP2) for nitrate (N-NO3), soluble reactive phosphorus ((SRP) P-PO4), and ammonium (N-NH4) concentrations reported in mg/L. This data package excludes from the final data product all but three WY2017 NO3N data due to column inefficiency during most measurements. The valid, analysis-ready data of this dataset therefore primarily represent two sets of Quality Assurance and Quality Control (QAQC) processed data from thirteen sites along the mainstem of the upper Clark Fork River: NH4N and SRP concentrations collected in water year 2017 (1 Oct 2016 - 30 Sept 2017) and NH4N, SRP, and NO3N collected in water year 2018 (1 Oct 2017 - 30 Sept 2018).

LTREB监测项目是针对克拉克弗拉特河（Clark Fork River）及其相关支流、源头溪流（含西尔弗博溪（Silver Bow Creek）与暖泉溪（Warm Springs Creek））开展生态修复的2亿美元超级基金（Superfund）项目的组成部分。
克拉克弗拉特河沿岸的修复工程包括移除富含重金属的河漫滩土壤、将河漫滩恢复至原始高程，以及对紧邻污染源的70余公里河漫滩实施植被重建。
LTREB监测项目沿受历史采矿活动污染的200公里修复梯度开展每两周一次的水质监测，旨在监测无机磷、氮浓度、生物现存量以及重金属污染状况。
本监测项目实施于蒙大拿州西部克拉克弗拉特河上游前200公里河段及相关支流区域。
该监测计划始于2017年，原定于2022年完成，或可获得经费延期。
本数据产品涵盖的地表水样本采集自克拉克弗拉特河上游干流沿线的13个监测点位。
每个监测点位的水样均采集三份平行样，并使用0.7 µm玻璃纤维滤膜进行过滤。
营养盐样本采用分光光度流动注射分析仪（AP2）进行分析，检测指标包括硝酸盐（N-NO3）、可溶性活性磷（(SRP) P-PO4）以及铵盐（N-NH4），浓度单位为mg/L。
由于多数检测过程中分析柱效率不佳，本数据包最终数据产品仅保留2017水年度的3组硝酸盐氮（NO3N）数据，其余同年度数据均已剔除。
因此本数据集经质量保证与质量控制（QAQC）处理后的有效可用数据主要包含两类：一是2017水年度（2016年10月1日—2017年9月30日）采集的铵盐氮（NH4N）与可溶性活性磷（SRP）浓度数据；二是2018水年度（2017年10月1日—2018年9月30日）采集的铵盐氮（NH4N）、可溶性活性磷（SRP）及硝酸盐氮（NO3N）浓度数据。