1. Limit Sets

2. Limit Sets Defined
Limit Sets - groups monitoring & reporting requirements for each Permitted Feature
Limit Sets typically apply during particular operating conditions such as:
Summer vs Winter
High production volume vs low production volume
Frequency of reporting (monthly, quarterly, yearly, etc)
Limit Sets define Discharge Monitoring Reports (DMRs)
What date range will be covered on the DMR form
When the first DMR will begin
when the DMRs are due to the Agency
The purpose of the Limit Sets is to group the monitoring and reporting requirements for each permitted feature based on the permit requirements. Limit Sets typically apply during particular operating conditions such as: summer versus winter months, and high production volume versus low production volume. In addition often times there are different frequencies of reporting, such as monthly, quarterly, semi-annual, yearly, A different limit set is created for each group. For instance canning vegetables – during the growing and canning season the limits would be different than low production time. A limit set will define the Discharge Monitoring Reports (DMRs). Data entered on the limit set determines what date range will be covered on the DMR form, when the first DMR will begin for that limit set, and when the DMRs are due to the Agency.

3. Limit Set Example 001 has monthly, quarterly, and yearly requirements
Create 3 Limit Sets - For Expected DMRs and Generation of Violations
Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec
X X X X X X X X X X X X
Monthly
X X X X
Quarterly X
Yearly
We will illustrate how the limit sets would be set up for Permitted feature 001 when the limits have requirements for monthly, quarterly, and yearly reporting. If you put all the parameters on one big limit set, you will get invalid non-reporting violations that will appear on the Internet and may be displayed on the Quarterly noncompliance report. When a facility has monthly reporting, a DMR must be submitted every month and if it is not submitted a non-receipt violation will be generated which is accurate. In the case of a quarterly DMR, generally they would have 4 DMR forms due in a year, and the DMR timeframe many times follow the calendar quarters. For instance, they would have a DMR from January 1st thru March 31st and another DMR from April 1st thru June 30th, etc. The facility would get valid non-reporting violations if any of the four quarterly DMRs were not submitted. However, if the quarterly requirements are combined with the monthly requirements on one limit set, all parameters would be expected monthly which is not accurate. The parameters that are required to be reported quarterly instead of monthly would get 8 months of invalid violations for failing to report the data every month. If you have a quarterly DMR from January 1 thru March 31st, the monitoring period end date is the date used for the DMR data entry, which in this case is March 31st. Invalid violations would appear for the months of January and February if you had put the requirements in one large monthly limit set. In the case of an annual requirement where they only have to submit one DMR from January 1st thru December 31st, if you group the limits in one monthly limit set, this facility would have invalid non-receipt violations for 11 months. The DMRs only need to be keyed for the end date of December 31st. For our example above, 3 limit sets should be created. One for monthly, one for quarterly and one for yearly requirements.

4. Actual Permit Language
General Foods, Permitted Feature 001
Let’s review the permit requirements for Permitted Feature 001 in our General Foods permit. Are there any parameters that require samples taken monthly, weekly, or daily. If so, we will need to create a limit set for monthly reporting. Yes, Flow, Cbod, TSS, etc. Are there other requirements for bi-monthly, quarterly, semi-annual, or yearly? Yes, quarterly requirements for lead and copper. We will need to create a limit set for quarterly reporting also. You will need to be careful because there are parameter requirements in the sentences at the bottom of this page and there are also parameter requirements in the “Special Conditions” of this permit. We will set up our two limit sets a little later on. One for monthly reporting and the other for quarterly reporting. In addition, we will need to review our INFL permitted feature to see what limit sets need to be created.

5. Types of Limit Sets There are two types of Limit Sets
Traditionally, Limit Sets are Scheduled
DMRs are expected on a predictable basis
Non-Receipt Violations are generated when 30 days late
There are two types of Limit Sets available, scheduled and unscheduled. The traditional limit sets are the scheduled ones. This means the DMRs are expected on a predictable basis, every month, every quarter, etc. The permit requires the DMR by a specific date and non-receipt violations are generated when the DMRs are overdue. Almost all limits in the database are scheduled limit sets.

6. Unscheduled Limit Sets
Special Regulatory Programs may need Unscheduled Limit Sets
DMRs are entered on an as-received basis
There is no DMR Due Date
DMR Non-Receipt Violations are never generated
Unschedule Limit Sets support the variable reporting needs of the Storm Water, Biosolids, and other programs
Appropriate for event-based reporting, rather than a continuous discharge
ICIS has the ability to track unscheduled DMRs. The Special Regulatory programs such as storm water may need unscheduled limit sets. DMRs may be due when certain conditions are met and a specific due date is not known. The DMRs are entered on as as-received basis, there is no DMR due date, and DMR non-receipt violations are never generated. Unscheduled limits sets can support the reporting needs of Storm Water, Biosolids, and other programs. The DMRs are event-based reporting rather than a continuous discharge.

7. Unscheduled Limit Sets
Comparison Chart
Scheduled Limit Sets
Unscheduled Limit Sets
Number of Report Units
Number of Submission Units
Modification Effective Date
Initial Monitoring Date
Modification Type
Initial DMR Due Date
You can see that there are more fields for scheduled limit sets than for unscheduled limit sets.

8. Expected DMRs
Using Limit Set (and Limit) data, ICIS-NPDES creates an Expected DMR Schedule
Allows users to see the expected discharge activity
Aids in validation of submitted DMR data
Scheduled Limit Sets get an Expected DMR Schedule when at least one Limit has been added to the Limit Set
Expected DMRs are created one-at-a-time as they are received for Unscheduled Limit Sets
The Expected DMR Schedule will be discussed more during the Limits and DMR units
The Limit Set along with at least one parameter limit requirement are used to create Expected DMRs in ICIS. You will be able to view the expected DMRs and this will aid in the validation that DMR data was submitted. For unscheduled limit sets, the expected DMRs are created one at a time as the DMR data is received. We will be discussing expected DMR schedules later in other modules.

9. Limit Set Decision Making
General Foods Permit
Should we set up limit sets for “Scheduled” or “Unscheduled” Limit Sets?
Do you know how often they should sample (monthly, quarterly?
Both – monthly and quarterly
are the DMRs due on a specific date? (check permit)
Yes. “no later than the 15th of the following month”
Scheduled or Unscheduled?
Scheduled
For our sample General Foods permit, should we create scheduled or unscheduled limit sets? Ask yourself these questions… Do you know how often they should sample, monthly, quarterly, yearly, etc. The answer is both monthly and quarterly for General Foods. Are the DMRs due on a specific date? Take a minute to review the Special Conditions in the permit to locate a DMR due date. After reviewing the General Foods permit we found that the DMRs are due “no later than the 15th of the following month”. So do we need scheduled or unscheduled limit sets? For General Foods we need scheduled limit sets.

10. Example of Report Units
Example of an actual permit with different reporting frequencies
This is an actual permit with different reporting frequencies. One for monthly, 3 for quarterly, 6 for semi-annual, and 12 for yearly DMRs.

11. Limits

12. Permit Limits in ICIS
How can I tell in ICIS if the Permitted Feature and Limit Sets have been entered?
How can I tell if the permitted features and limit sets have been entered into ICIS? Once you search the permit and click on Permitted Features hyperlink, you should see a permitted feature, such as 001, 002, SUM, etc. To see the limit sets as displayed on this screen, click on the Limit Set hyperlink. You will see 3 limit sets that were created for our General Foods example permit.

13. Parameter Limit Defined
A Limit is a parameter (something to be measured) with associated numerical limits or monitoring requirements for a release to the environment from a permitted feature
A parameter may be one of the following
Chemical (e.g., phosphorus)
Biological organism (e.g., fecal coliform)
Physical condition (e.g., temperature)
Characteristic (e.g., pH)
A limit is a parameter, something to be measured with associated numerical limits or monitoring requirements for a release to the environment from a permitted feature. A parameter may be a chemical, biological organism, physical condition or a characteristic. Examples of those parameters that are monitored are phosphorus, fecal coliform, temperature and pH.

14. Parameter Limits on DMR Form
Limit Values determine the data a Permittee has to report on DMRs for a parameter
Limit Values determine the data a permittee has to report on the Discharge Monitoring Report (D M R) form for a specific parameter. Values can be reported in 5 columns on the DMR form. Quantity or Loading average and maximum and concentration minimum, average and maximum fields.

15. ICIS Columns Defined
ICIS refers to the value fields as Q1, Q2, C1, C2 and C3.
The terms “Average”, “Maximum” and Minimums” have no meaning as the Statistical Base code defines the type measurement taken for each value field.
ICIS is more flexible than the DMR form, and will allow up to 5 minimums, 5 averages, or 5 maximum values for each parameter limit. Q1 Q2 C1 C2 C3
For the 5 columns on the DMR form, the terms that are displayed on the form show the quantity or loading average and maximum and quality or concentration minimum, average and maximum. In our legacy database these column titles were used to enter minimum, averages and maximums. Later on when toxicity was added to permits it was necessary to be able to enter 2 minimums. To allow for the most flexibility in ICIS, the statistical base code is added to the permit requirement gray box to explain whether the value should be reported as a minimum, average or maximum value. You could enter up to 5 minimums, up to 5 averages, or up to 5 maximums or any combination. For consistency, many of the parameters are entered using the minimum, average and maximum columns if possible. ICIS refers to the columns as Q1, Q2 for the quantity or loading values, and C1, C2, and C3 for the concentration values. Coding these fields will be discussed at length a little later on in this module.

16. Limit Segments
Limits are organized within a Limit Set by Parameter (e.g., Ammonia Nitrogen)
A Parameter is defined as a collection of Limit Segments that have matching
NPDES ID
Permitted Feature Identifier
Limit Set Designator
Parameter Code
Monitoring Location Code
Season ID
Limits are organized within a limit set by parameter, for example Ammonia Nitrogen. A parameter is defined as a collection of limit segments that have a matching NPDES id, permitted feature identifer, limit set designator, parameter code, monitoring location and a season id.

17. Limit Segments
Segments are the actual Limits or monitoring requirements for a Parameter
Usually Segments for a Parameter have different Limit Start and/or End Dates
There are three kinds of Limit Segments
Base Limits
Permit Modification Limits (PML)
Enforcement Action Limits (EA)
Let’s talk about Limit Segments. What do we mean by limit segment? A limit segment are the actual limits or monitoring requirements for a parameter. Usually segments have a different limit start date and or a different end date. There are three kinds of limit segments. Base limits, permit modification limits referred to as P M L and enforcement action limits referred to as E A.

18. Limit Segments
Base Limits are the Limits initially issued with the Permit
PMLs are Limits that result from a Permit Modification
EA Limits are the Limits applied by an Enforcement Action’s Final Order
Limits for Segments within a Parameter can overlap each other
When Limits overlap, there is a hierarchy that determines which segment applies for a given point in time
EA Limits supercede PMLs and Base Limits
PMLs supercede Base Limits
Base limits are the limits initally issued within the permit. P M L s are limits that result from a permit modification. E A Limits are the limits applied by an enforcement actions final order. Limit segments within a parameter can overlap each other. When the limits overlap, there is a hierarchy that determines which segment applies for a given point in time. An enforcement action limit will supercede a modification or base limit. A modification limit will supercede the base limit. Let’s review an example of the 3 limit segments for the parameter Arsenic.

19. Limit Segments for Arsenic
PARAMETER
(VA , 001-A, Arsenic, Effluent Gross, Season 1)
Base Limit
Start
End
Value = 4
PML
Start
End
Value = 2
Only one limit segment can be in effect at a time. The Base limit usually has a start and end date for the 5 year permit. As you can see the limit value is equal to 4. When the permit modification starts, it overrules the base limit, so the value is now 2. When the enforcement action limit starts, it will overrule the modification and the base limit, so the value is now 7. At the end of the segment, the system will check to see if a permit modification is in effect and if not will revert back to the base limit. You can tell by the darker blue color when the E A limit ended, ICIS checks the permit modification’s end date and in this case the modified limit ended before the E A limit, so ICIS will revert back to the base limit.
Enforcement Action Limit
Start
End
Value = 7

20. Limit Segments ICIS Example of Limit Segments Base Limit Modification
Enforcement Action Limit
This is an example of how the segments would look in ICIS. The base limit has a start date which is the effective date of the permit and an end date on the expiration date of the permit. From September 2012 thru December 2012 the base limit is in effect. Then the modification start date is January 2013 and the limit is in effect until the enforcement action limit starts which is July When the enforcement action limit ends on October 31, 2013, ICIS will check to see the end date on the permit modification. Since the modification date was before the end date of the enforcement action limit of 10/31/2013, the limit will revert back to the base limit which ends in One note …. if the end date is the same for multiple segments, the hierarchy that we discussed earlier is in effect. Enforcement action overrules all, then the modification overrules the base limit.

21. Test Your Knowledge
Which limit is in effect for the month? Base, Mod, or Enf Action
July 2011
March 2012
September 2010
December 2010
October 2015
Test your knowledge. Which limit is in effect for the five months displayed on this screen? The base limit, modification limit or the enforcement action limit. Remember the hierarchy – it’s tricky.

22. Test Your Knowledge - Answer
Which limit is in effect for the month? Base, Mod, or Enf Action
July Enf Action
March Mod
September Base
December Enf Action
October Mod
And the answers are July 2011 is enforcement action, March 2012 is from a modification, September 2010 is from Base Limit, December 2010 is from an Enforcement Action and October 2015 is from a MOD. Remember if the mod and base limit end on the expiration date of the permit, the modification rules.

23. Expected DMRs
An Expected DMR Schedule is generated when Limits are added to a Limit Set
Parameters with a limit value or monitoring requirement will show on the expected DMRs
Once a parameter is entered, ICIS will generate an expected DMR schedule. You can view the expected DMRs in ICIS. The expected DMRs are similar to a place holder for data that is expected to be reported. The expected DMR data is used to evaluate whether the expected data was reported or not and to automatically generate non-receipt violations. Expected DMRs will be discussed further in the DMR module.

24. Limit Segments
If DMR data have been received for a segment and a new segment is added, the data may be moved to the new segment
Updates to Limits such as changing dates and months will result in updates to the Expected DMR Schedule
Any changes to the Expected DMR Schedule may result in updates to Violations for the received DMR data
Any change that will result in orphaned received DMR data will be rejected
A little more about segments. If DMR data has been received for a segment and a new segment is added, the data may move to the new segment if it is within the time frame. Updates to limits such as changing dates and months will result in updates to the expected DMR schedule. Any changes to the expected DMR schedule may result in updates to violations for the received DMR data. Any change that will result in orphaned received DMR data will be rejected. In the limit set module we discussed orphaned data and had some examples. If you need a refresher, you can access the Limit Set module.

25. Limit Segments
When the Permit’s Expiration Date is reached its Limits remain in effect
Base and PML segments with Limit End Date = Permit Expiration date are eligible for Administrative Continuance
If more than one Segment is eligible for Administrative Continuance for a Parameter, the one highest in the hierarchy will be continued
When the permit’s expiration date is reached, the limits remain in effect. If the base limit and or permit modified limit have an end date that is the same as the permit expiration date, the limits are eligible for Administrative Continuance. If more than one segment is eligible for Administrative continuance, the one highest in the hierarchy will be continued. In this case, the modified permit limits would be in effect.