In 2013, Klity Creek became the site of Thailand's first legally required remediation, 15 years after the spill of lead (Pb)‐contaminated mine tailings into the creek. Even today, nature cannot attenuate Pb‐contaminated sediment, arguably due to either high geological background Pb or continuous leakage of Pb from the unlined tailing ponds, upstream of the creek. In this study, four lines of evidence were used to reveal that the leakage from tailing ponds is primarily responsible for the long‐term Pb contamination. First, stable Pb isotope ratios (²⁰⁶Pb/²⁰⁷Pb and ²⁰⁸Pb/²⁰⁷Pb) were used to apportion sources between the tailings and geological background. The analysis of samples from the tailing ponds, geological background, and local zinc (Zn)‐Pb deposit revealed five different Pb sources (i.e., two distinct mine tailings, two different backgrounds, and a local Zn‐Pb deposit) in the area based on five unique isotope ratios. Using source apportionment analysis, Pb‐contaminated sediments in Klity Creek were consistent with tailings being the dominant source (30%–100%). Likewise, an analysis of Pb radionuclide (²¹⁰Pb) revealed the Pb in the contaminated sediment was relatively new, 0–6.7 years old, suggesting that the Pb source was recent leakage from the tailing ponds rather than the 15‐year‐old tailing spill. Isotope evidence was supported by the elevated Pb‐contaminated seepage (0.30 ± 0.22 mg/L) from the tailing ponds and groundwater samples (up to 0.225 mg/L) collected from monitoring wells surrounding the tailing ponds. Consequently, proper management of Pb leakage from the tailing ponds is critical for successful Klity Creek remediation.

中文翻译：

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从废弃矿山尾矿池到泰国北碧府Klity Creek的铅（Pb）泄漏评估

2013年，在铅（Pb）污染的矿山尾矿溢入小河15年后，Klity Creek成为泰国第一个法律要求的补救地点。即使到了今天，自然界也无法减弱受铅污染的沉积物，这可能是由于高地质背景的铅或小溪上游无衬砌的尾矿池不断泄漏的铅所致。在这项研究中，使用四项证据来揭示尾矿池的泄漏是造成长期铅污染的主要原因。首先，稳定的Pb同位素比（²⁰⁶ Pb / ²⁰⁷ Pb和²⁰⁸ Pb / ²⁰⁷Pb）用于在尾矿和地质背景之间分配来源。对来自尾矿池，地质背景和当地锌（Zn）-Pb矿床的样品进行分析后发现，该地区有五种不同的Pb来源（即两种不同的矿山尾矿，两种不同的背景以及一种本地的Zn-Pb矿床）。五个独特的同位素比率。使用源分配分析，在Klity Creek中受Pb污染的沉积物与尾矿为主要来源一致（30％–100％）。同样，分析Pb放射性核素（²¹⁰Pb）表明受污染的沉积物中的Pb较新，为0-6.7年，这表明Pb源是最近从尾矿池泄漏的，而不是15年之久的尾矿溢漏。尾矿池中铅污染的增加（0.30±0.22 mg / L）和尾矿池周围监测井收集的地下水样品（最高0.225 mg / L）为同位素证据提供了支持。因此，正确处理尾矿池中的铅泄漏对于成功进行Klity Creek治理至关重要。