In December 2016, EPA announced the review results for the Agency’s third Six-Year Review (called Six-Year Review 3). EPA analyzed compliance monitoring data for the Six-Year Review 3 using data provided by states/primacy agencies through the Information Collection Request (ICR) for Six-Year Review 3 covering January 2006 through December 2011. Each zip file contains data for multiple contaminants and related information that can be unzipped into tab delimited text files. The number of records and associated systems in the data files and the size of the files range considerably from contaminant to contaminant, which may be attributed to many factors such as the applicability of monitoring requirements, the required sampling frequency and results from quality assurance/quality control (QA/QC) measures. A detailed description of the data fields and their definitions, notes about the data, and instructions for downloading and importing datasets into software applications such as Excel can be found in the User Guide. Citation information for this dataset can be found in Data.gov's References section.

The Safe Drinking Water Act (SDWA) requires EPA to review each National Primary Drinking Water Regulation (NPDWR) at least once every six years and revise them, if appropriate. The purpose of the review, called the Six-Year Review, is to identify those NPDWRs for which current health effects assessments, changes in technology, and/or other factors provide a health or technical basis to support a regulatory revision that will maintain or strengthen public health protection. To support the national contaminant occurrence and exposure assessments performed under the Six-Year Review process, EPA analyzes SDWA compliance monitoring data from public water supplies for regulated drinking water contaminants. This analysis allows EPA to characterize the national occurrence of contaminants to help the Agency determine if there may be a meaningful opportunity to improve public health protection.

The Safe Drinking Water Act (SDWA) requires EPA to review each National Primary Drinking Water Regulation (NPDWR) at least once every six years and revise them, if appropriate. The purpose of the review, called the Six-Year Review, is to identify those NPDWRs for which current health effects assessments, changes in technology, and/or other factors provide a health or technical basis to support a regulatory revision that will maintain or strengthen public health protection. To support the national contaminant occurrence and exposure assessments performed under the Six-Year Review process, EPA analyzes SDWA compliance monitoring data from public water supplies for regulated drinking water contaminants. This analysis allows EPA to characterize the national occurrence of contaminants to help the Agency determine if there may be a meaningful opportunity to improve public health protection.

Integrated Compliance Information System (ICIS) National Pollutant Discharge Elimination System (NPDES) Discharge Monitoring Report (DMR) data sets for Clean Water Act permitted dischargers.

This is the 2014 Integrated Report. EPA approved this submission in accordance with Sections 303(d), 305(b), and 314(l) of the Clean Water Act, on October 16, 2015. The Integrated Report (IR) combines two water quality reports required under sections 305(b) and 303(d) of the federal Clean Water Act. Section 305(b) requires states, territories and authorized tribes to perform annual water quality assessments to determine the status of jurisdictional waters. Section 303(d) requires states, territories and authorized tribes to identify waters assessed as not meeting water quality standards(see Code of Maryland Regulations 26.08.02). Waters that do not meet standards may require a Total Maximum Daily Load to determine the maximum amount of an impairing substance or pollutant that a particular water body can assimilate and still meet water quality criteria. Historically, the 303(d) List and the 305(b) report were submitted to the Environmental Protection Agency (EPA) as separate documents but more recent guidance has called for combining these two reports into a single biennial publication. More information is available at http://www.mde.state.md.us/PROGRAMS/WATER/TMDL/INTEGRATED303DREPORTS/Pages/Programs/WaterPrograms/TMDL/Maryland%20303%20dlist/index.aspx A searchable version of this data is available at http://www.mde.state.md.us/programs/Water/TMDL/Integrated303dReports/Pages/303d.aspx

Integrated Compliance Information System (ICIS) National Pollutant Discharge Elimination System (NPDES) Discharge Monitoring Report (DMR) data sets for Clean Water Act permitted dischargers.