NPDES Permit Basics

Understanding what’s in your Permit

Part Four of Four

This is the last in a series of four articles about NPDES permits for Publicly-owned Treatment Works (POTWs). The first three articles in this series discussed Technology-based limits-—TBELs-—and Water quality-based effluent limits-—WQBELs-— in both numerical and narrative form. This article discusses what may be the most important aspect of Permits as they apply to Certified Operators: reporting. Because the reporting rules are so complicated, and because some NPDES permit provisions conflict with the regulations, this article cannot prescribe what to do in all situations. Attempts to obtain clarification from DEP have not been successful, although at the time of writing (fall, 2017) we have received some preliminary and informal comments that might result in revision of this article if they are affirmed by DEP administrative staff.

In any situation where a requirement is unclear, contact with DEP should be made (and recorded or documented) so that inadvertent reporting violations do not occur. Keep in mind that this article provides only a general description of the requirements; the regulations and NPDES permit should always be consulted when any sort of incident occurs. (The Certification regulations require that a copy of the permit must be provided to all Certified Operators.)

Because all Certified Operators are required to report to the Owner any actual or potential permit or regulatory violations, it might appear that the discharge limits in the Permit are all that you need to know. Also, the Certification regulations do not require Certified Operators to report anything directly to DEP. However, the NPDES regulations and permits include reporting requirements that go beyond the Certification regulations and may affect operators directly. In particular, the requirements to report any unusual releases “immediately” and certain others within 24 hours may affect operators on duty when an event occurs. The telephone number for emergency reporting to your DEP regional office should be posted so that all operators can comply with these requirements.

One last caveat: To keep the article to a manageable size, I have not discussed all of the EPA regulations, which in some cases are somewhat different from the DEP regulations and permits. Most (not all) of the federal requirements are reflected in the Permit, although in different places than are discussed here.[1] Also, because of the complexity, I have constructed a matrix that shows the three sets of requirements for many different possible scenarios; this may not be accurate for all events and is not intended to instruct you on the legal requirements. It is meant to help point to the sections to look at when an event occurs.

DMR/Supplemental DMR
The first kind of report required by the permit is the monthly Discharge Monitoring Report, or DMR. This is a standard form (now usually in electronic form) that summarizes treatment plant performance for the prior month. In addition to the DMR, most DEP regional offices are also requiring “Supplemental” DMR forms, reporting such data as MLSS and biosolids generation and disposal. Note that the frequency and kind of data collection is controlled by the NPDES Permit, not the reporting forms. Thus, although the Supplemental DMRs have a place to enter MLSS each day, this does not create a requirement to sample MLSS each day; similarly, if a particular parameter is not monitored, you are not required to start doing so just because a column for it appears on the Supplement DMR form; data only need to be entered as they are generated as part of routine system monitoring. Since these reports are usually prepared by the plant superintendent and the operators are not directly involved, I won’t discuss them further in this article.

The real concern with reporting is the myriad of special conditions that are required to be reported at differing times by both the Regulations and the permits. These fall into two general categories: routine changes and unexpected events. For each, I provide a discussion of the regulations and the NPDES permits which, unfortunately, do not always agree with each other.

Planned Changes-—DEP Regulation
DEP regulations (§ 92a.24(a)) require reporting three kinds of changes that might result from a planned change in the wastestream or a change in treatment plant processes [2]: (1) a discharge of “new” pollutants not limited in the permit; (2) an increase in the discharge of pollutants with no effluent limit; or (3) an increase in effluent pollutants that might violate effluent limits. The regulation states that any of these changes must be reported to DEP in advance and written permission obtained from DEP before the change is made. [3] In some cases DEP might require an application for a revised NPDES permit to be submitted so that the changed circumstances can be addressed through new permit conditions.

This requirement is an integral part of a concept created by the Clean Water Act and incorporated into the DEP regulations (§ 92a.6): the “permit as a shield” rule. In effect, the burden of protecting the environment falls on the government; once a discharger submits all of the relevant data, DEP decides what permit conditions are necessary to protect the environment. The “permit as a shield” rule says that as long as the POTW complies with the permit, it is deemed to be in compliance with the statute. That is, as long as all permit conditions are met, even if a pollution event occurs, it is not a violation by the permittee since it was DEP’s duty to include all of the necessary protections in the permit. This concept fails, of course, if the information changes. That is, if DEP does not know that an industrial user has started or increased its discharge of, say, “methyl-ethyl death” into the sewer system, it cannot determine what permit conditions, if any, are necessary to deal with it. Thus, the regulation requires the POTW to report whenever the influent is proposed to contain new or increased pollutants and receive written permission from DEP to do so.

Planned Changes-—NPDES Permits
While the regulation is not a model of clarity, the situation is complicated by the fact that NPDES permits include somewhat different requirements. Similarly to the regulations, permits include a requirement to report any planned “new” pollutants due to industrial discharges or hauled wastes; “new” pollutants are defined as those not detected in the last permit application or which were not previously present in industrial wastes. [4] However, regarding “increased” pollutants (those detected in the last Permit application), the permit differs somewhat from the regulations.

First, while the regulation requires reporting (and getting permission to accept) any increase of existing pollutants with no effluent limit (i.e., those reported at low levels in the permit application so that no effluent limit was necessary), this is not required by the permit. Instead, only increases of more than 20% of the loading reported in the permit application are to be reported. Also, in addition to the regulatory requirement to report increases that could violate an effluent limit, the permit also requires reporting increases that could; (1) violate a water quality standard in the receiving water or (2) interfere with plant operations. This means that the POTW must evaluate the probable effect of a proposed increase in influent pollutants on (1) the in-stream concentration and (2) plant operations before deciding whether to report and get permission to accept it. Because these requirements are so different, they must be evaluated carefully to determine when reporting is required under the regulations and when it is required under the permit. Why? Because the regulations require obtaining written permission to accept an increased pollutant, while the permit does not. In fact, the permit states that if DEP ignores the report and does not give permission, “the permittee may proceed with the increase.”

Unplanned Changes-—NPDES Permits
In addition to addressing a limited class of proposed increases, the permit also requires reporting when an actual increase is more than 20% higher than the highest influent loading reported in the last renewal application. This requirement does not appear in the regulations (but the EPA regulation does require it; see footnote [1]). In addition, since it is found in an un-numbered paragraph of the permit under section C.2 of the Permit, captioned “Planned changes,” it might not be noticed. [5]

Comparing Regulatory and Permit Requirements. The fact that a regulatory requirement does not appear in a permit does not mean you can ignore the regulation. So, since there are two sets of slightly different requirements, one in the permit and one in the regulations, operators should be aware of both sets of requirements and report to management when any new or increased pollutant occurs or is planned so that management can decide whether to report the information to DEP. Because of the differing requirements of the regulations and the permits, I prepared the attached matrix to help in this decision, which addresses the following possibilities:

• Proposed introduction of a new pollutant not previously detected in a permit application, or not previously found in industrial or hauled wastes (both regulation and permit)

• Actual (but unplanned) acceptance of a new pollutant (permit only-—Part B.I.C)

• Proposed increase of a “known” pollutant (i.e., one that showed up on the most recent application testing) for which there is no effluent limit in the permit (regulation; permit applies if the proposed increase is >“ 20% of existing load†)

• Proposed increase of a “known” pollutant that would result in an effluent limit violation (both regulation and permit)

• Proposed increase of a “known” pollutant that would result in a water quality criterion violation (permit only)

• Proposed increase of a “known” pollutant that would result in interference with POTW operations (permit only).

• Proposed increase of a “known” pollutant that would not cause any of the above results (permit only, but only if the increase is >“ 20% of the existing load†)

• Actual (unplanned) increase of a “known” pollutant loading by >“20% † (permit § A.I.C.)

• Actual (unplanned) increase of a “known” pollutant loading by

In addition to the above requirements applicable to influent changes, the regulations and permits require reporting of unexpected discharge events. There are two different requirements: one in the DEP regulations and one in the EPA regulations.

Unexpected Events-—EPA Rules and the Permit 
The EPA regulations (40 CFR §122.41(l)(6)) are found in Part A.III.C of the permit and require reporting within 24 hours when one of these three events occurs:

• An unanticipated “bypass” (with certain exceptions);
• An “upset” that violates effluent limits; or
• A violation of a daily maximum limit that appears in the permit and is specially marked as reportable under this provision (no such limits appear in DEP-issued permits, so this reporting requirement can be ignored)

“Bypass” is defined in the EPA regulations (40 CFR § 122.41(m)) as when a portion of the forward flow is routed around one or more entire treatment processes. An “upset” (§ 122.41(n)) is narrowly defined as an exceptional and unintentional incident that violates Technology-based limits, which we discussed in the first installment of this series (e.g., C-BOD, TSS and TRC).

DEP includes the EPA rules regarding bypasses in Part B of the permits. There are three types of bypass: (1) necessary for essential maintenance and does not result in an effluent limits violation; (2) unavoidable to prevent injury or “severe property damage;” and (3) any other bypass. The reporting rules are different for each. For the first type, no report is necessary (although I would recommend documenting what happened so that the criteria-—”essential maintenance” and “no violations”-—are on record). For the other two types, a report should be submitted ten days prior to the bypass if possible and within 24 hours if the bypass is unexpected (see the first bullet point above regarding the EPA 24-hour reports). If the report is timely submitted, DEP cannot take enforcement action for the second type of bypass (unavoidable to prevent injury or severe damage), but other instances of bypass are a violation, even if timely reported.[6]

In addition to reporting these events within 24 hours, the EPA regulation requires that a follow-up written report be submitted within 5 days, describing the event, its cause and duration, and steps taken to correct it and prevent reoccurrence. This written report may be waived by DEP at the time the oral report is made (be sure to ask when making the initial report).

Unexpected Events-—DEP Regulations and Permit
The DEP regulations require reporting several types of discharge and potential discharge events that are not addressed by the EPA regulations discussed above. Section 91.33 of the DEP regulations requires reporting any “accident or other activity or incident” that results in a discharge of a pollutant to a waterway (including ditches and drains) or “placed so that it might discharge.” The “person in charge” must report to DEP “immediately” by telephone. For no apparent reason, this Chapter 91 rule is modified in Chapter 92a of the DEP rules. Section 92a.41(b) provides that reports under this section must be submitted as soon as possible but always within four hours. This section also requires that a written report similar to the one in the EPA 24-hour reporting rule be submitted within 5 days. Note that, although this rule is superficially similar to the EPA 24-hour reporting rule, it covers different types of events. Also, there is no provision for DEP to waive the 5 day written report under this section. The Section 91.33 rule also includes requirements to (1) notify downstream users if possible, and (2) clean up the release within 15 days.

Probably of most interest to operators, this provision applies to sanitary sewer overflows (SSOs) as well as other sorts of spills or releases. Note that the report is required only if the discharge reaches, or has the potential to reach, a waterway. Overflows or leaks on a site that are contained so that they do not reach a waterway are not subject to this reporting requirement (although some DEP field staff may insist otherwise).

DEP has developed Supplemental Noncompliance forms to report these discharges and violations. Most of these forms are available on the DEP website or from the Regional office.

There is no DEP regulation for “upsets,” so an upset is reportable within 24 hours under the EPA regulation discussed above.[7]

Compliance Schedules-—EPA Rules
EPA regulations provide that if there is a compliance schedule in the Permit, a report of compliance or non-compliance must be submitted within 14 days of each schedule due date. 40 CFR § 122.41(l)(5).

Compliance Schedules-—NPDES Permit
Part B of DEP-issued NPDES permits contains the EPA requirement above, but extends the requirement well beyond schedules. The Permit states that a report is to be submitted for compliance or non-compliance with “any interim and final requirements contained in this Permit. Such reports shall be submitted no later than 14 days following the applicable schedule date or compliance deadline.” Since effluent limits are final permit requirements with a compliance deadline of the effective date of the permit, this provision requires a report that the POTW is meeting its effluent limits to be submitted within 14 days of the effective date of the permit when it is first issued.

Other Reports 
This article is not comprehensive and does not discuss reports such as the annual “Chapter 94” and industrial pretreatment program reports, whole effluent toxicity testing reports (again, DEP permits differ from the EPA requirements), special studies, and other such things. All operators should review the entire NPDES permit and identify the various kinds of reports that are required. While you may not need to submit the report yourself, your diligence may help the administrative staff avoid a permit violation.

Because of the number of reporting requirements, and the fact that there are three different sets of them (EPA regulations, DEP regulations, and NPDES permits), a matrix is attached which should help identify what requirements apply to what sort of event. In all cases, if there is a question DEP should be contacted and a written record kept of the advice received regarding how, when, and what to report.

[1] For instance, EPA rules require giving “adequate notice” of any “substantial change” in pollutants received from industrial users, while the DEP rules only address planned changes. A truncated version of the EPA requirement is found in Part B.I.C.4 of the permit, which requires reporting certain kinds of industrial waste changes in the annual Wasteload Management (“Chapter 94”) report.

[2] Since the regulations apply to all dischargers, including industrial sources, they are worded very broadly and include reporting changes in treatment processes. However, since substantial modifications to POTW treatment processes may only be made pursuant to a DEP permit, this reporting requirement will only be triggered by a new or changed industrial waste discharge into the system: a “change in waste stream.”

[3] It is not known under what circumstances DEP might approve an increase that would cause a violation of effluent limits, so that part of the requirement seems pointless.

[4] The permit condition actually states any “new introduction of pollutants into the POTW,” which literally would mean any new industrial user, regardless of whether the pollutants were already present from another source. In an attempt to reconcile the regulations and the permit, and in the absence of clarification from DEP, I have assumed that this phrase is intended to mean the “introduction of new pollutants.”

[5] DEP has informally stated that this provision does not require reporting increases in pollutants if they are not planned. If that position is confirmed by a responsible official, we will revise this article and the decision matrix accordingly.

[6] Failure to report a violation is itself a violation, so bypasses should be reported even if they are not excusable.

[7] The EPA regulations state than an upset is a defense to a violation because it is beyond the reasonable control of the operator. However, DEP has not adopted this rule and treats upsets as permit violation.

1. By definition, a “New” Pollutant is one that was not detected in the influent during the last permit application and, therefore, has no permit limit. However, many detected pollutants (i.e., “existing” pollutants) will also not have a permit limit, so the determination of a “new pollutant” or “existing” pollutant depends on a review of the Application, not the Permit.

2. The 20% criterion is based on maximum loading in the most recent Permit Application

† Most of the EPA Regulations are either restated, or incorporated by reference, in the DEP regulations of Chapter 92a. Where they are not, the entry so indicates (e.g., upsets).

‡ Note that a violation occurs even if effluent limits are met during these bypasses.

© Mette, Evans & Woodside. May be reproduced only with author’s permission. This summary table does not constitute legal advice and should not be relied on to determine legal obligations.


Other articles in the NPDES Permit Basics – Understanding what’s in your Permit:

Article I: NPDES Technology Based Effluent Limits
Article II: NPDES Water Quality-Based Effluent Limits
Article III: NPDES Technology-Based Effluent Limits
Article IV: NPDES Permit Basics