1.1 本指南涵盖了为获取代表性地下水信息和颗粒含水层水质样本而安装的屏蔽井的开发，尽管本文所述方法也可应用于其他用途的井。本指南中未描述仅用于裸眼基岩井的其他油井开发方法。 1.2 本指南中所述方法的应用和局限性基于以下假设，即所应用方法的监测井的主要目标是从含水层中获取具有代表性的水质样本。使用本指南所述方法开发的筛选监测井应能从砾石到粉砂等颗粒状含水层材料中获得相对无沉积物的样品。虽然许多监测井被视为“小直径”井（即小于10厘米[4英寸）。 ]内径），本指南中描述的一些技术将更容易应用于大直径井（即10 cm[4 in]或更大内径）。 1.3 以国际单位制或英寸-磅单位表示的数值应单独视为标准值。每个系统中规定的值可能不是精确的等效值；因此，每个系统应相互独立使用。将两个系统的值合并可能会导致不符合标准。 1.4 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.5 本指南提供了有组织的信息收集或一系列选项，并不推荐具体的行动方案。 本文件不能取代教育或经验，应与专业判断一起使用。并非本指南的所有方面都适用于所有情况。本ASTM标准不代表或取代需要判断给定专业服务是否充分的谨慎标准，也不应在不考虑项目的许多独特方面的情况下应用本文件。本文件标题中的“标准”一词仅表示该文件已通过ASTM共识程序获得批准。 1.6 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 4.1 正确设计、安装和开发的地下水监测井，按照实践建造 D5092 应提供以下内容:可分析的代表性地下水样本，以确定样本的物理性质和水质参数，或代表由油井筛选的该部分含水层总水头的电位水平，或两者兼而有之。该井也可用于进行含水层性能测试，以确定完井的目标水文地层单元的水文地质特性。 注1: 内布拉斯加州灌浆工作队从2001年到2009年以及随后几年对环形密封剂进行了广泛的研究计划（Lackey等人，2009年和加利福尼亚州，2015年）。这项研究包括水泥和膨润土灌浆以及颗粒和碎屑的使用。 研究的总体发现表明，所有密封方法都会在非饱和带的油井部分出现收缩。最好的灌浆是水泥砂、膨润土碎屑、纯水泥和固体含量超过20%的膨润土泥浆。尤其是在不饱和带使用低固体含量的膨润土泥浆，导致加利福尼亚州禁止使用这些泥浆（加利福尼亚州，2015年）。强烈建议在设计之前评估有关非饱和区密封的州和联邦规范/法规，以确保符合规范。 4.2 油井开发是监测完井的重要组成部分。应充分开发安装在含水层中的监测井，使其达到预期目标。油井开发方法因筛选监测井的目标水文地层单元的物理特征、油井的施工细节、油井安装前钻孔施工期间使用的钻井方法以及地下水质量而异。 每个监测井的开发方法应从本指南所述的几种方法中选择，并应由井施工承包商或负责监测井完井的合格人员使用。 4.3 油井开发在监测油井中的重要性无论怎样估计都不为过。如果监测井与项目一起继承，则最好由井施工承包商或合格人员考虑未进行井开发或未充分进行井开发的可能性，如果井未重新开发和/或无法获得适当的井开发文件，这可能会影响之前和未来的采样结果。适当和仔细的油井开发将提高大多数监测井提供代表性、无偏化学和水力数据的能力。 在监测完井或维护过程中执行这一重要步骤所花费的额外时间和金钱将减少损坏泵送设备和现场传感器的可能性，并增加地下水样本代表所监测目标地层水的可能性。实践 D3740 提供本指南中活动的评估因素。 注2: 本标准产生的结果的质量取决于执行该标准的人员的能力，以及所用设备和设施的适用性。符合实践标准的机构 D3740 通常认为能够胜任和客观的测试/采样/评估/等。本标准的用户应注意遵守惯例 D3740 本身并不能保证可靠的结果。可靠的结果取决于许多因素。实践 D3740 提供了一种评估其中一些因素的方法。

1.1 This guide covers the development of screened wells installed for the purpose of obtaining representative groundwater information and water quality samples from granular aquifers, though the methods described herein could also be applied to wells used for other purposes. Other well-development methods that are used exclusively in open-borehole bedrock wells are not described in this guide. 1.2 The applications and limitations of the methods described in this guide are based on the assumption that the primary objective of the monitoring wells to which the methods are applied is to obtain representative water quality samples from aquifers. Screened monitoring wells developed using the methods described in this guide should yield relatively sediment-free samples from granular aquifer materials, ranging from gravels to silty sands. While many monitoring wells are considered “small-diameter” wells (that is, less than 10 cm [4 in.] inside diameter), some of the techniques described in this guide will be more easily applied to large-diameter wells (that is, 10 cm [4 in.] or greater inside diameter). 1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.5 This guide offers an organized collection of information or a series of options and does not recommend a specific course of action. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this guide may be applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the adequacy of a given professional service needs to be judged, nor should this document be applied without consideration of a project's many unique aspects. The word “Standard” in the title of this document means only that the document has been approved through the ASTM consensus process. 1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 4.1 A correctly designed, installed, and developed groundwater monitoring well, constructed in accordance with Practice D5092 should provide the following: representative samples of groundwater that can be analyzed to determine physical properties and water quality parameters of the sample or potentiometric levels that are representative of the total hydraulic head of that portion of the aquifer screened by the well, or both. The well may also be utilized for conducting aquifer performance tests used for the purpose of determining the hydrogeologic properties of the targeted hydrostratigraphic unit in which the well has been completed. Note 1: An extensive research program on annular sealants was conducted from 2001 through 2009 and in subsequent years by the Nebraska Grout Task Force (Lackey et al., 2009 and State of California, 2015). This research included cement and bentonite grouts and the use of pellets and chips. The general finding of the study indicates all sealing methods suffer from some shrinkage in the portion of the well in the unsaturated zone. The best grouts were cement-sand, bentonite chips, neat cements, and bentonite slurries with more than 20 percent solids. Especially problematic is the use of low solids content bentonite slurries in the unsaturated zone leading to a prohibition on their use in California (State of California, 2015). It is also highly recommended that State and Federal codes/regulations regarding seals within the unsaturated zone be evaluated prior to design to ensure codes are met. 4.2 Well development is an important component of monitoring well completions. Monitoring wells installed in aquifers should be sufficiently developed to such that they serve their intended objectives. Well development methods vary with the physical characteristics of the targeted hydrostratigraphic unit in which the monitoring well is screened, the construction details of the well, the drilling method utilized during the construction of the borehole prior to well installation, and the quality of the groundwater. The development method for each individual monitoring well should be selected from among the several methods described in this guide and should be employed by the well construction contractor or the qualified personnel in responsible charge of the monitoring well completion. 4.3 The importance of well development in monitoring wells cannot be overestimated. If a monitoring well is inherited with a project, it is best for the well construction contractor or the qualified personnel to consider the possibility that well development was not performed or was carried out inadequately, which may influence both previous and future sampling results if the wells were not redeveloped and/or appropriate documentation of well development cannot be obtained. Proper and careful well development will improve the ability of most monitoring wells to provide representative, unbiased chemical and hydraulic data. The additional time and money spent performing this important step in monitoring well completion or maintenance will reduce the potential for damaging pumping equipment and in situ sensors, and increase the probability that groundwater samples are representative of the targeted formation water monitored. Practice D3740 provides evaluation factors for the activities in this guide. Note 2: The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/evaluation/and the like. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors. Practice D3740 provides a means of evaluating some of those factors.