Effluent Charts Help

Effluent Charts allows you to create charts and tables of effluent limits, measurements, and violations over time for Clean Water Act (CWA) discharge permits issued under the National Pollutant Discharge Elimination System (NPDES). Information about NPDES discharge measurement is available under "CWA/NPDES Compliance Status" in the ECHO Data Dictionary.

Here you can find help with the following topics:

Getting to the Charts
Viewing the Charts
Viewing and Downloading Data
Custom Searches
Data Considerations

There are two ways to arrive at a page of effluent charts:

• From facility search results. When you run a PCS or ICIS-NPDES query in ECHO and get a list of facilities, every icon and every non-zero number in the "Quarters in Noncompliance" column is a link to a page of effluent charts for its facility:
• From a Detailed Facility Report. In any Detailed Facility Report that includes a CWA permit, the "Three Year Compliance Status" section includes links to effluent charts for that permit: Each parameter name is a link to a page of effluent charts for that parameter in that permit. "All violations" links to a page of charts for all parameters for which there was a violation for the given permit. "Custom" links to a custom search form, prefilled with data about the parameters and discharge points for this permit, where you can choose which charts you want to see and then create them.

Clicking on any of the links highlighted above will take you to a page of charts for your selected permit and parameters. At the top of the page is a table showing the search criteria: Revise search will take you to a custom search form with all of your previous selections in place, so you can revise them and search again. Download will give you a listing of the data in all of the charts on this page; see Downloading Data for details.

Below the list of search criteria is a table of information about the selected permit: Below that is the series of effluent charts, grouped by parameter. Each chart shows all of the effluent measures, permitted limits, and effluent violations for the given dates, for a single permit, discharge point, parameter, monitoring location, and sampling period. The charts show different violation data for PCS and ICIS-NPDES permits, reflecting the different information stored about violations in those systems.

ICIS-NPDES records violation data for each permitted limit: up to three concentrations (identified as concentrations 1, 2, and 3; typically specified in the permit as minimum, average, and maximum concentrations) and two quantities (quantities 1 and 2; typically average and maximum) for each outfall, parameter, monitoring location, and monitoring period. The charts for ICIS-NPDES permits show these violation data in separate quantity and concentration violation plots above the corresponding effluent plots:

• A Legend link leads to a popup legend that explains the meanings of the different lines and symbols.
• Hover your mouse pointer over any measurement symbol or limit line to see a text balloon containing the measurement or limit value.
• Click anywhere on the chart image, or on the View Detail link above it, to see a printable page showing the permit information, a larger chart, legend, and a table of the data used to create the chart.

PCS records the same information as ICIS-NPDES about permitted limits and effluent discharges, but it has less detailed information about violations. For a given outfall, parameter, monitoring location, and monitoring period, PCS will only record at most one violation for the up to five permitted measures (concentration 1, 2, 3; quantity 1 and 2), and it does not record which of the measures caused it. If more than one permitted measure causes a violation in the same reporting period, then only the most severe violation is recorded. Therefore, effluent charts for PCS permits include only a single violation plot at the top, showing the recorded worst violation for each monitoring period: For PCS permits, the effluent value markers are filled in when the discharge values exceed their permitted limits (or go below them, in the case of minimum limits). This may be presumed to be the cause of an effluent violation in PCS, even though PCS itself does not record that information. To download a table of the data for all of the charts on a chart page, click on the Download button at the top of that page.

To view a table of the data shown in one chart, click anywhere on the chart, or on the View Detail link above it. You will be taken to a printable page that includes a data table: Measurements are shown in bold red when they exceed their permitted limits.

Click on the Download button above the table to download the data from just that table.

Clicking on either the "custom" link in a Detailed Facility Report, or the "Revise query" button on a page of effluent charts, will take you to an effluent data query form prefilled with information about that permit:

The update form button is enabled when you enter a new, valid (9 letters and digits) NPDES permit ID. If you click on it, the form will be refilled with information associated with that permit.

Under "Select charts", the With violations button selects only those charts that include effluent violations. All selects all of the charts for which there is some data available, whether or not they include violations.

Under Monitoring locations and Outfall types, the Effluents only checkboxes select only the monitoring locations or outfall types associated with effluent discharges. All selects all outfall types or monitoring locations, not just those associated with effluent discharges.

When you've made your selections, click on any Search button to create the page of charts.

The Effluent Charts only show effluent data and violations. They do not show single-event violations.

Under certain circumstances, Effluent Charts may appear to be missing effluent, limit, or violation data. There are several reasons for this apparent lack of information, which may be broken into the following cases:

Numeric limits are present without measurement data or violations. This can occur in the presence of "no data indicator" codes (NODI), which are used in PCS to indicate why data is not entered (lost sample, operation shutdown, etc.) and suppress violation generation. Also, in some cases for non-major permits, states do not have DMR non-receipt tracking turned on in PCS. Without this functionality, missing measurements will not result in violations.

Effluent measurements are present without corresponding numeric limits. This may reflect a condition where "monitoring only" is either optional or required.

No limit or measurement data are shown for a specific time period. Lack of limit or measurement data may be due to seasonal limits or optional monitoring. Lack of measurement data for required monitoring will generate violations, unless DMR non-receipt tracking is turned off.

There are competing violations at the same time for the same parameter under quantity and concentration. PCS contains only one violation field per parameter per time period, and therefore prioritizes violations with effluent violations taking priority over missing values.