Kentucky Division of Water Issues New Multi-Sector General Stormwater Permit

Environmental Consulting

August 29, 2023

Share it with the world!

Title 40 of the Code of Federal Regulations (40 CFR) Part 122.26 outlines the Environmental Protection Agency (EPA) administered program for stormwater discharges known as the National Pollutant Discharge Elimination System (NPDES). The Kentucky Division for Environmental Protection (KDEP) is responsible for implementing Kentucky’s NPDES program (KPDES). Facilities located in Kentucky that discharge stormwater which encounters industrial activity are required to obtain a KPDES permit from the Kentucky Division of Water (KDOW) to discharge such stormwater.

Stormwater discharge includes discharge that is directly related to manufacturing, processing, or raw materials storage areas at an industrial facility. Certain qualifying facilities may choose to obtain coverage by KDOW under the Multi-Sector General Permit, permit ID KYR000000 (KYR00), which includes pre-established terms and conditions applicable to all covered facilities. Facilities with an individual KPDES permit for process wastewater discharges often have stormwater discharge requirements rolled into their individual KPDES in lieu of obtaining coverage under KYR00.

KYR00 expired on July 31, 2023, and was renewed by KDOW with an effective date of August 1, 2023. Facilities currently covered under KYR00 have 90 days from the effective date of the permit (i.e., October 30, 2023) to submit a complete Notice of Intent (NOI) to request continued coverage under the renewed general permit. Whether a facility is seeking renewed coverage or obtaining coverage under KYR00 for the first time, it is important to understand the changes in requirements associated with the new permit to ensure ongoing compliance is maintained. The NOI must be submitted using KDOW’s web-based eNOI-KYR00 form on Kentucky’s EEC eForms Portal, accessed through the Kentucky Online Gateway. There is no fee for applying. Facilities that discharge stormwater which is covered under an individual KPDES permit are not required to submit a NOI for coverage under KYR00.

KDOW has incorporated several changes to the permit terms and conditions within KYR00. The most notable changes include an updated list of industries that can obtain coverage under the general permit, new effluent limitations and monitoring requirements, and more clearly defined sample collection and analysis procedures.

New Industries Covered

As part of the renewal of KYR00, KDOW has included additional types of industries that may qualify for coverage under the general permit. New industries that may obtain coverage under KYR00 include the following:

Timber facilities
- Sawmills (SIC code 2421)
- Fabricated wood containers (SIC code 2449)
- Logging storage (SIC code 2411), including wet decking
Facilities discharging non-contact cooling waters along with stormwater
State, county, and local governmental agency highway maintenance garages

KDOW estimates that including the above industries in the list of covered facilities will incorporate over 155 facilities, including at least 30 facilities currently covered under an individual KPDES permit. With the incorporation of these new facilities, the list of excluded facilities that may not obtain coverage under KYR00 has also been expanded. The following exclusions have been added to KYR00:

Those discharges that are subject to a promulgated national effluent guideline specific to stormwater discharges except as allowed under the Timber Products Category
Timber processing facilities with stormwater discharges from areas where there may be contact with the chemical formulations sprayed to provide surface protection
Those facilities that are privately-owned and operated maintenance garages
Any facility whose primary function is vehicle or equipment cleaning

All other exclusions previously listed in the general permit remain unchanged.

New Effluent Limitations and Monitoring Requirements

Facilities covered under the general permit are subject to effluent limitations and benchmark monitoring. Under the previous general permit, covered facilities were required to conduct benchmark monitoring via grab samples twice per year, and to submit the results of such monitoring within Discharge Monitoring Reports (DMRs) by January 28th and July 28th through NetDMR. Upon issuance of the renewed general permit, facilities previously covered have become subject to new monitoring requirements for chemical oxygen demand (COD) and surfactants. Effluent flow, pH, total suspended solids (TSS) and oil and grease are required to be monitored as before. Facilities subject to these requirements are categorized as “stormwater only” to separate them from the new industries covered by KYR00. Consistent with the previous general permit, “stormwater only” industries are required to complete the benchmark monitoring semiannually, and DMRs are still due January 28th and July 28th. These requirements are summarized in Table 1 below.

Table 1.

Effluent Limitations							Monitoring Requirements
Effluent Characteristics	Loadings (lb/day)		Concentrations				Monitoring Requirements
Effluent Characteristics	Monthly Average	Daily Maximum	Units	Minimum	Monthly Average	Daily Maximum	Frequency²	Sample Type
Flow	Report	Report	MGD	N/A	N/A	N/A	2/Year	Calculated
pH	N/A	N/A	SU	6.0	N/A	9.0	2/Year	Grab
Total Suspended Solids	N/A	N/A	mg/L	N/A	Report	100¹	2/Year	Grab
Oil & Grease	N/A	N/A	mg/L	N/A	Report	15	2/Year	Grab
Chemical Oxygen Demand	N/A	N/A	mg/L	N/A	Report	Report	2/Year	Grab
Surfactants³	N/A	N/A	mg/L	N/A	Report	Report	2/Year	Grab
¹100 mg/l is not an effluent limit, but a trigger. Should the daily maximum of Total Suspended Solids (TSS) exceed 100 mg/l for two (2) consecutive reporting periods, see BMP Evaluation Trigger for TSS Section of this permit for additional requirements. ²Discharge Monitoring Report (DMR) data shall be submitted by July 28^th and by January 28^th. ³If washwaters containing detergents are not used or are transported to a POTW, use NODI Code 9 for reporting. N/A means Not Applicable.

The new industries that may obtain coverage under KYR00 are subject to different additional effluent limitations and benchmark monitoring requirements than the “stormwater only” industries. Newly covered timber facilities are required to monitor outfalls for total recoverable zinc and hardness (as CaCO3) if sawmills are operated onsite. Facilities that discharge non-contact cooling water alongside stormwater and that obtain coverage under KYR00 are required to monitor outfalls for temperature and total residual chlorine. Lastly, highway maintenance garages are required to monitor outfalls for chlorides and surfactants. Like the “stormwater only” category of facilities, all three new categories of facilities are required to monitor effluent flow, pH, TSS, oil and grease, and COD. Results of the monitoring prescribed by KYR00 for facilities in these new categories are due quarterly, or by January 28th, April 28th, July 28th, and October 28th. Tables 2-4 below summarize the effluent limitations for the timber products, non-contact cooling waters, and highway maintenance garages categories.

Table 2.

Effluent Limitations							Monitoring Requirements
Effluent Characteristics	Loadings (lb/day)		Concentrations				Monitoring Requirements
Effluent Characteristics	Monthly Average	Daily Maximum	Units	Minimum	Monthly Average	Daily Maximum	Frequency	Sample Type
Flow	Report	Report	MGD	N/A	N/A	N/A	1/Quarter	Calculated
pH	N/A	N/A	SU	6.0	N/A	9.0	1/Quarter	Grab
Total Suspended Solids	N/A	N/A	mg/L	N/A	Report	100¹	1/Quarter	Grab
Oil & Grease	N/A	N/A	mg/L	N/A	10	15	1/Quarter	Grab
Chemical Oxygen Demand	N/A	N/A	mg/L	N/A	Report	Report	2/Year	Grab
Hardness (as CaCO₃)²	N/A	N/A	mg/L	N/A	Report	Report	1/Quarter	Grab
Total Recoverable Zinc²	N/A	N/A	mg/L	N/A	Report	0.12	1/Quarter	Grab
¹100 mg/l is not an effluent limit, but a trigger. Should the daily maximum of Total Suspended Solids (TSS) exceed 100 mg/l for two (2) consecutive reporting periods, see BMP Evaluation Trigger for TSS Section of this permit for additional requirements. ²Use NODI Code 9 for reporting if no sawmill is on site.

Table 3.

Effluent Limitations							Monitoring Requirements
Effluent Characteristics	Loadings (lb/day)		Concentrations				Monitoring Requirements
Effluent Characteristics	Monthly Average	Daily Maximum	Units	Minimum	Monthly Average	Daily Maximum	Frequency	Sample Type
Flow	Report	Report	MGD	N/A	N/A	N/A	1/Quarter	Calculated
pH	N/A	N/A	SU	6.0	N/A	9.0	1/Quarter	Grab
Total Suspended Solids	N/A	N/A	mg/L	N/A	Report	100¹	1/Quarter	Grab
Oil & Grease	N/A	N/A	mg/L	N/A	10	15	1/Quarter	Grab
Chemical Oxygen Demand	N/A	N/A	mg/L	N/A	Report	Report	2/Year	Grab
Temperature²	N/A	N/A	*F	N/A	Report	89	1/Quarter	Grab
Total Residual Chlorine³	N/A	N/A	mg/L	N/A	Report	0.019	1/Quarter	Grab
¹100 mg/l is not an effluent limit, but a trigger. Should the daily maximum of Total Suspended Solids (TSS) exceed 100 mg/l for two (2) consecutive reporting periods, see BMP Evaluation Trigger for TSS Section of this permit for additional requirements. ²Use NODI Code 9 if discharge contains stormwater only with no non-contact cooling waters. ³Use NODI Code 9 for reporting if municipal water is not used.

Table 4.

Effluent Limitations							Monitoring Requirements
Effluent Characteristics	Loadings (lb/day)		Concentrations				Monitoring Requirements
Effluent Characteristics	Monthly Average	Daily Maximum	Units	Minimum	Monthly Average	Daily Maximum	Frequency	Sample Type
Flow	Report	Report	MGD	N/A	N/A	N/A	1/Quarter	Calculated
pH	N/A	N/A	SU	6.0	N/A	9.0	1/Quarter	Grab
Total Suspended Solids	N/A	N/A	mg/L	N/A	Report	100¹	1/Quarter	Grab
Oil & Grease	N/A	N/A	mg/L	N/A	10	15	1/Quarter	Grab
Chemical Oxygen Demand	N/A	N/A	mg/L	N/A	Report	Report	2/Year	Grab
Chlorides²	N/A	N/A	mg/L	N/A	N/A	1200	1/Quarter	Grab
Surfactants³	N/A	N/A	mg/L	N/A	Report	Report	1/Quarter	Grab
¹100 mg/l is not an effluent limit, but a trigger. Should the daily maximum of Total Suspended Solids (TSS) exceed 100 mg/l for two (2) consecutive reporting periods, see BMP Evaluation Trigger for TSS Section of this permit for additional requirements. ²Year-round sampling is required if bulk road salt is stored or handled at the facility during any portion of the year. Use NODI Code 9 for reporting if not required. ³If washwaters containing detergents are not used or are transported to a POTW, use NODI Code 9 for reporting.

Sample Collection and Analysis

To complete the required benchmark monitoring outlined above, facilities will have to carefully schedule when to collect grab samples at their outfalls. The previous general permit only specified that stormwater samples were to be collected during periods of stormwater discharge. 40 CFR 122.26 requires sampling to be conducted within 30 minutes (or as soon as practicable) of a storm event (i.e., greater than 0.1 inches of rainfall) and at least 72 hours from the previous storm event. KDOW has historically followed this federal requirement and has rolled this requirement directly into the renewed general permit. KYR00 also now specifies that, should a facility be unable to collect the sample within 30 minutes of a qualified storm event, the facility shall keep documentation in its Stormwater Pollution Prevention Plan (SWPPP)/Best Management Practices Plan (BMPP) explaining why it was not possible to take samples within the first 30 minutes. Samples shall be performed by Kentucky Energy and Environment Cabinet (KY EEC) certified general wastewater laboratories and EEC certified field-only laboratories. A list of certified laboratories can be obtained by emailing the DOW Laboratory Certification Section at [email protected].

Permittees are required to update their existing SWPPP within 180 days of the effective date of the renewed general permit, or by January 28, 2024, to ensure compliance with all provisions of KYR00. In addition to administrative updates, permittees should review and update the plan’s monitoring requirements in accordance with the new effluent limitations. Trinity recommends conducting a walkthrough of the facility to identify changes to potential pollutant sources, physical control measures, best management practices, or other relevant operational changes to ensure that all requirements of the renewed KYR00 are being met.

If you would like to discuss the new general permit requirements and how they may impact your facility, please contact Trinity’s Covington, KY office or call 859.341.8100.

Trinity provides the environmental compliance expertise we need to keep our business flowing. The amount of collaboration between us has established a high level of trust. Trinity is always looking out for our best interest.

Brent Jensen/Frazier

Manufacturing Director of EHS and HR