Who this article is for: Authority users who create and manage discharge limits.
Overview
This article covers the hands-on management of discharge limits: creating new limits on an outfall, editing and deleting them, toggling their active status, and connecting them to General Controls. For conceptual background on limit types, definitions, rationales, and how enforceability works, see Discharge Limits: Types, Rationales, and Enforceability.
Before You Begin
Limits are created at the outfall level. Navigate to Industrial Users > select an IU > select an Outfall.
Adding a Limit
In the Discharge Limits section of the outfall page, click New Limit (or Add Limit > New Limit, where your organization has limit libraries). The button is available while the outfall is active — an inactive outfall does not accept new limits.
Fill in the required fields in the window that opens.
Click Save to create the limit.
Required Fields
Field | Description |
Analyte | Select the pollutant or parameter this limit applies to (e.g., BOD, TSS, pH, Lead). |
Limit Unit | Select a unit compatible with the selected analyte and limit type. |
Limit Type | Select how the limit is evaluated (e.g., Daily Maximum, Monthly Average, Instantaneous). |
Limit Definition | Select Compliance or Notification. |
Limit Rationale | Search and select the regulatory basis. General holds Local limits, Authority (other), Surcharge, Notification and TRC. A CFR rationale cites a specific standard: under Federal Categorical Standards, type at least two characters to search the 40 CFR catalog. |
Min and Max Values
Enter a Min Value, a Max Value, or both. At least one is required.
Field | Description |
Min Value | The minimum acceptable value (e.g., 6.0 for pH). |
Max Value | The maximum acceptable value (e.g., 9.0 for pH, or 250 for BOD mg/L). |
💡 Analyte, Limit Unit, and Limit Type use three-way filtering. Selecting any one field narrows the available options for the other two based on compatibility. For example, selecting a concentration analyte filters units to Milligrams per liter, Micrograms per liter, and so on, and filters limit types to those compatible with concentration measurements.
💡 Picking an analyte fills in its usual unit for you, replacing any unit already selected. You can then change the unit. If the suggested unit would not work with a limit type you already picked, the unit is left empty for you to choose a compatible one, and your limit type is kept as-is.
The Limit Detail Page
Click a limit's row in the outfall's Discharge Limits table to open it in a window, where you can review and edit its details without leaving the outfall page.
Each limit also has its own detail page, which contains:
Limit Summary card — shows the limit's analyte, type, unit, definition, rationale, min/max values, and status. Includes Edit and Delete actions (when available based on status).
Enforceability card (Compliance limits only) — shows all legal controls connected to this limit in a table with Status, Legal Control Name, Effective Date, Expiration Date, Termination Date, Inactive On, and Template Name columns. Clicking a row navigates to that legal control's detail page. Includes the + General Control button for manually connecting to General Controls.
Connecting a Limit to a General Control
The + General Control button on the Enforceability card lets you manually connect a Compliance limit to a General Control:
Open the limit detail page.
In the Enforceability card, click + General Control.
Select the General Control from the dropdown (already-connected controls are excluded).
Click Confirm.
The connection appears as a new row in the Enforceability table. You can connect a limit to multiple General Controls.
📝 The + General Control button is only available for Compliance limits that are not in Inactive status. Notification limits do not have an Enforceability section.
Limits are connected to permits (Specific Controls) through the permit creation process, not from the limit detail page. See Discharge Limits: Types, Rationales, and Enforceability for details on how this works.
Editing a Limit
Compliance limits can be edited while in New status; once connected to a control they are locked. Notification limits can be edited in any status from the limit's window on the outfall page. On the limit detail page:
Open the limit detail page.
Click Edit in the header.
Update values and save.
📝 If the limit was originally created with a limit type that has since been deprecated, the system will clear the limit type field and display a warning. You must select a new limit type before saving.
Deleting a Limit
Limits can be deleted when they are in New status or have a Notification definition:
Open the limit detail page.
Click Delete in the header.
Confirm the deletion in the modal.
⚠️ Deleting a limit is permanent and cannot be undone.
Activating and Deactivating a Limit
How a limit is activated depends on its definition:
Notification limits can be toggled on and off freely using the Active toggle switch on the limit detail page. Their status does not depend on legal controls.
Compliance limits are activated based on the status of the legal control they are connected to. When a legal control (permit or General Control) is active, the compliance limits connected to it are active. A Compliance limit that is Active, Upcoming, or Available can also be switched off with the Active toggle, unless it is enforced by an active or upcoming permit. The system blocks that change. Where permit revisions are turned on for your organization, the limit is changed through a permit revision instead; otherwise, it is changed by terminating the permit and creating a new one. An inactive Compliance limit can be switched back on with the Active toggle.
This distinction also affects what happens when an IU or outfall is reactivated after being set to inactive:
Notification limits are automatically reactivated when the parent outfall is reactivated
Compliance limits are not — they stay inactive until each one is switched back on with the Active toggle.
⚠️ Reactivating an IU or outfall does not reactivate its Compliance limits. They stay Inactive in the Discharge Limits section until switched back on.
FAQ
Q: What is the difference between Min Value and Max Value?
A: Min Value sets the lower boundary and Max Value sets the upper boundary. A limit can have just a max (most common for pollutant limits), just a min (e.g., for pH minimum), or both (for range-based limits like pH 6.0-9.0).
Q: Why can't I select certain units or limit types?
A: Units, limit types, and analytes are filtered by compatibility. Selecting one narrows the options for the other two. For example, you cannot assign temperature units to a concentration-based analyte.
Q: How do I create a range limit (like pH 6.0-9.0)?
A: Create a limit with the analyte set to pH, use the "Instant Range (High-Low Values)" limit type, and enter both a Min Value (6.0) and Max Value (9.0).
Q: Why can't I see the + General Control button?
A: The button only appears for Compliance limits that are not in Inactive status. Check that your limit's definition is set to Compliance and that it is not inactive.
Q: How do I connect a limit to a permit?
A: Limits are added to a permit in Step 2 (Limits) of the permit wizard, not from the limit detail page. See Discharge Limits: Types, Rationales, and Enforceability for details.