US EPA Air Quality Design Values for Criteria Pollutants

This web service contains layers which depict Design Values for the following criteria air pollutants: Lead (Pb), Annual and Daily Fine Particulate Matter (PM2.5), Particulate Matter (PM10), Carbon Monoxide (CO), Sulfur Dioxide (SO2), Ozone (O3), and Nitrogen Dioxide (NO2). A design value is a statistic that describes the air quality status of a given location relative to the level of the National Ambient Air Quality Standards (NAAQS). This GIS dataset includes design values for individual monitoring sites, counties, and nonattainment areas, where applicable. Design values are defined to be consistent with the individual NAAQS as described in CFR Part 50. Design values are typically used to designate and classify nonattainment areas, as well as to assess progress towards meeting the NAAQS. Design values are computed and published annually by EPA's Office of Air and Radiation (OAR) and reviewed in conjunction with the EPA Regional Offices. Some of these design values can change after the date of publication for a variety of reasons, including but not limited to: 1) EPA agreement that certain data were influenced by exceptional events and therefore not subject for comparison with the NAAQS, 2) States retroactively entering or changing erroneous data based on later findings, and/or 3) notification of a monitoring issue (e.g. network design, site combination, change in the regulatory status of a monitor) that would prompt a revision. The information contained in this web service is intended for informational use only and does not constitute a regulatory determination by EPA as whether an area has attained a NAAQS. The information set forth in this report has no regulatory effect. To have regulatory effect, a final EPA determination as to whether an area has attained a NAAQS or attained a NAAQS as of its applicable attainment date can be accomplished only after rulemaking that provides an opportunity for notice and comment. No such determination for regulatory purposes exists in the absence of such rulemaking.

本Web服务提供的图层可描绘以下标准管控空气污染物的设计值（Design Values）：铅（Lead, Pb）、年平均与日平均细颗粒物（Fine Particulate Matter, PM2.5）、可吸入颗粒物（Particulate Matter, PM10）、一氧化碳（Carbon Monoxide, CO）、二氧化硫（Sulfur Dioxide, SO2）、臭氧（Ozone, O3）及二氧化氮（Nitrogen Dioxide, NO2）。设计值是一类统计指标，用于描述特定区域的空气质量状况与国家环境空气质量标准（National Ambient Air Quality Standards, NAAQS）限值的对应关系。本地理信息系统（Geographic Information System, GIS）数据集涵盖了适用情形下各监测站点、郡县及未达标区域的设计值。设计值的定义需符合《联邦法规汇编》（Code of Federal Regulations, CFR）第50部分中明确的各项国家环境空气质量标准。设计值通常用于划定、分类未达标区域，同时也可用于评估区域达成国家环境空气质量标准的进展情况。设计值由美国环境保护署（Environmental Protection Agency, EPA）空气与辐射办公室（Office of Air and Radiation, OAR）每年计算并发布，并会同EPA区域办公室开展审核。部分设计值在发布后可能因多种原因发生变更，包括但不限于：1）EPA认定部分数据受异常事件影响，不应与国家环境空气质量标准进行比对；2）各州基于后续调查结果回溯补录或修正错误数据；3）收到监测相关问题（如监测网络设计、站点合并、监测站监管状态变更等）的通知并因此启动修订。本Web服务所包含的信息仅用于参考用途，不构成美国环境保护署对某区域是否达到国家环境空气质量标准的监管判定。本Web服务所载信息不具备监管效力。若要具备监管效力，EPA需针对某区域是否达到国家环境空气质量标准，或是否在其适用达标日期前达到标准作出最终判定，而该判定仅能通过开展包含公示与意见征询环节的规则制定程序后方可作出。若未开展此类规则制定程序，则不存在具备监管效力的相关判定。